Timed Text (TT) Authoring Format 1.0 – Distribution Format Exchange Profile (DFXP)

1 Introduction

Unless specified otherwise, this section and its sub-sections are non-normative.

The Timed Text Authoring Format (TT AF) Distribution Format Exchange Profile (DFXP) provides a standardized representation of a particular subset of textual information with which stylistic, layout, and timing semantics are associated by an author or an authoring system for the purpose of interchange and potential presentation.

DFXP is expressly designed to meet only a limited set of requirements established by [TTAF1-REQ] , and summarized in J Requirements . In particular, only those requirements which service the need of performing interchange with existing, legacy distribution systems are satisfied.

In addition to being used for interchange among legacy distribution content formats, DFXP content may be used directly as a distribution format, providing, for example, a standard content format to reference from a <text> or <textstream> media object element in a [SMIL 2.1] document. Certain properties of DFXP support streamability of content, as described in M Streaming DFXP Content .

Note:

While DFXP was not expressly designed for direct (embedded) integration into a SMIL document instance, such integration is not precluded.

Note:

In some contexts of use, it may be appropriate to employ animated content to depict sign language representations of the same content as expressed by a Timed Text document instance. This use case is not explicitly addressed by DFXP mechanisms, but may be addressed by some external multimedia integration technology, such as SMIL.

1.1 System Model

Use of DFXP is intended to function in a wider context of Timed Text Authoring and Distribution mechanisms that are based upon a system model, depicted in Figure 1 – System Model , wherein the timed text authoring format serves as a bidirectional interchange format among a heterogeneous collection of authoring systems, and as a unidirectional interchange format to a heterogeneous collection of distribution formats after undergoing transcoding or compilation to the target distribution formats as required, and where one particular distribution format is DFXP.

Figure 1 – System Model

1.2 Document Example

A DFXP document instance consists of a tt document element that contains a header and a body, where the header specifies document level metadata, styling definitions and layout definitions, and the body specifies text content intermixed with references to style and layout information and inline timing information.

Example Fragment – DFXP Document Structure
<tt xml:lang="" xmlns="http://www.w3.org/2006/10/ttaf1"> <head> <metadata/> <styling/> <layout/> </head> <body/> </tt>

Document level metadata may specify a document title, description, and copyright information. In addition, arbitrary metadata drawn from other namespaces may be specified.

Example Fragment – DFXP Metadata
<metadata xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata"> <ttm:title>Timed Text DFXP Example</ttm:title> <ttm:copyright>The Authors (c) 2006</ttm:copyright> </metadata>

Styling information may be specified in the form of style specification definitions that are referenced by layout and content information.

In Example Fragment – DFXP Styling , four style sets of specifications are defined, with one set serving as a collection of default styles.

Example Fragment – DFXP Styling
<styling xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling"> <!-- s1 specifies default color, font, and text alignment --> <style xml:id="s1" tts:color="white" tts:fontFamily="proportionalSansSerif" tts:fontSize="22px" tts:textAlign="center" /> <!-- alternative using yellow text but otherwise the same as style s1 --> <style xml:id="s2" style="s1" tts:color="yellow"/> <!-- a style based on s1 but justified to the right --> <style xml:id="s1Right" style="s1" tts:textAlign="end" /> <!-- a style based on s2 but justified to the left --> <style xml:id="s2Left" style="s2" tts:textAlign="start" /> </styling>

Example Fragment – DFXP Styling

<styling xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <!-- s1 specifies default color, font, and text alignment -->
  <style xml:id="s1"
    tts:color="white"
    tts:fontFamily="proportionalSansSerif"
    tts:fontSize="22px"
    tts:textAlign="center"
  />
  <!-- alternative using yellow text but otherwise the same as style s1 -->
  <style xml:id="s2" style="s1" tts:color="yellow"/>
  <!-- a style based on s1 but justified to the right -->
  <style xml:id="s1Right" style="s1" tts:textAlign="end" />     
  <!-- a style based on s2 but justified to the left -->
  <style xml:id="s2Left" style="s2" tts:textAlign="start" />
</styling>

Layout information defines one or more regions into which content is intended to be presented. A region definition may reference one or more sets of style specifications in order to permit content flowed in the region to inherit from these styles. In Example Fragment – DFXP Layout , the region definition makes reference to style specification s1 which allows all content flowed into the region to inherit from the region's styles (in the case that a style is not already explicitly specified on content or inherited via the content hierarchy.)

Example Fragment – DFXP Layout
<layout xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling"> <region xml:id="subtitleArea" style="s1" tts:extent="560px 62px" tts:padding="5px 3px" tts:backgroundColor="black" tts:displayAlign="after" /> </layout>

Example Fragment – DFXP Layout

<layout xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <region xml:id="subtitleArea"
    style="s1"
    tts:extent="560px 62px"
    tts:padding="5px 3px"
    tts:backgroundColor="black"
    tts:displayAlign="after"
  />
</layout>

The content of a DFXP document instance is expressed in its body, which is organized in terms of block and inline text elements. The hierarchical organization of content elements serves a primary role in determining both spatial and temporal relationships. For example, in Example Fragment – DFXP Body , each paragraph ( p element) is flowed into its target region in the specified lexical order; furthermore, the active time interval of each paragraph is timed in accordance to its parent or sibling according to the applicable time containment semantics — in this case, the division parent is interpreted as a parallel time container.

Example Fragment – DFXP Body
<body region="subtitleArea"> <div> <p xml:id="subtitle1" begin="0.76s" end="3.45s"> It seems a paradox, does it not, </p> <p xml:id="subtitle2" begin="5.0s" end="10.0s"> that the image formed on<br/> the Retina should be inverted? </p> <p xml:id="subtitle3" begin="10.0s" end="16.0s" style="s2"> It is puzzling, why is it<br/> we do not see things upside-down? </p> <p xml:id="subtitle4" begin="17.2s" end="23.0s"> You have never heard the Theory,<br/> then, that the Brain also is inverted? </p> <p xml:id="subtitle5" begin="23.0s" end="27.0s" style="s2"> No indeed! What a beautiful fact! </p> <p xml:id="subtitle6a" begin="28.0s" end="34.6s" style="s2Left"> But how is it proved? </p> <p xml:id="subtitle6b" begin="28.0s" end="34.6s" style="s1Right"> Thus: what we call </p> <p xml:id="subtitle7" begin="34.6s" end="45.0s" style="s1Right"> the vertex of the Brain<br/> is really its base </p> <p xml:id="subtitle8" begin="45.0s" end="52.0s" style="s1Right"> and what we call its base<br/> is really its vertex, </p> <p xml:id="subtitle9a" begin="53.5s" end="58.7s"> it is simply a question of nomenclature. </p> <p xml:id="subtitle9b" begin="53.5s" end="58.7s" style="s2"> How truly delightful! </p> </div> </body>

Example Fragment – DFXP Body

<body region="subtitleArea">
  <div>
    <p xml:id="subtitle1" begin="0.76s" end="3.45s">
      It seems a paradox, does it not,
    </p>
    <p xml:id="subtitle2" begin="5.0s" end="10.0s">
      that the image formed on<br/>
      the Retina should be inverted?
    </p>
    <p xml:id="subtitle3" begin="10.0s" end="16.0s" style="s2">
      It is puzzling, why is it<br/>
      we do not see things upside-down?
    </p>
    <p xml:id="subtitle4" begin="17.2s" end="23.0s">
      You have never heard the Theory,<br/>
      then, that the Brain also is inverted?
    </p>
    <p xml:id="subtitle5" begin="23.0s" end="27.0s" style="s2">
      No indeed! What a beautiful fact!
    </p>
    <p xml:id="subtitle6a" begin="28.0s" end="34.6s" style="s2Left">
      But how is it proved?
    </p>
    <p xml:id="subtitle6b" begin="28.0s" end="34.6s" style="s1Right">
      Thus: what we call
    </p>
    <p xml:id="subtitle7" begin="34.6s" end="45.0s" style="s1Right">
      the vertex of the Brain<br/>
      is really its base
    </p>
    <p xml:id="subtitle8" begin="45.0s" end="52.0s" style="s1Right">
      and what we call its base<br/>
      is really its vertex,
    </p>
    <p xml:id="subtitle9a" begin="53.5s" end="58.7s">
      it is simply a question of nomenclature.
    </p>
    <p xml:id="subtitle9b" begin="53.5s" end="58.7s" style="s2">
      How truly delightful!
    </p>
  </div>    
</body>

The first subtitle Subtitle 1 – Time Interval [0.76, 3.45) is presented during the time interval 0.76 to 3.45 seconds. This subtitle inherits its font family, font size, foreground color, and text alignment from the region into which it is presented. Since no region is explicitly specified on the paragraph, the nearest ancestor that specifies a region determines the region. Note also that content is presented at the bottom (after edge) of the containing region due to the tts:displayAlign="after" being specified on the region definition.

Note:

The notation "[ X , Y ]" denotes a closed interval from X to Y , including X and Y ; "[ X , Y )" denotes a right half-open interval from X to Y , including X but not including Y ; "( X , Y ]" denotes a left half-open interval from X to Y , not including X but including Y ; "( X , Y )" denotes an open interval from X to Y , not including X or Y .

Subtitle 1 – Time Interval [0.76, 3.45)

The second subtitle continues with the default style, except that it contains two lines of text with an intervening author-specified line break. Note the effects of the use of tts:textAlign="center" to specify the paragraph's alignment in the inline progression direction.

Subtitle 2 – Time Interval [5.0, 10.0)

The third subtitle continues, using a variant style which overrides the default style's foreground color with a different color.

Subtitle 3 – Time Interval [10.0, 16.0)

The fourth subtitle reverts to the default style.

Subtitle 4 – Time Interval [17.2, 23.0)

The fifth subtitle continues, again using a variant style which overrides the default style's foreground color with a different color.

Subtitle 5 – Time Interval [23.0, 27.0)

During the next active time interval, two distinct subtitles are simultaneously active, with the paragraph expressing each subtitle using a different style that overrides color and paragraph text alignment of the default style. Note that the flow order is determined by the lexical order of elements as they appear in the content hierarchy.

Subtitles 6a and 6b – Time Interval [28.0, 34.6)

The next subtitle is specified in a similar manner using a style override to give a paragraph right (end) justified in the inline progression direction.

Subtitle 7 – Time Interval [34.6, 45.0)

The eighth subtitle uses the same style override as the previous subtitle in order to maintain the right (end) justification of the paragraph.

Subtitle 8 – Time Interval [47.3, 49.0)

During the final (ninth) active time interval, two distinct subtitles are again simultaneously active, but with a different style applied to the second paragraph to override the default color. Note that the flow order is determined by the lexical order of elements as they appear in the content hierarchy.

Subtitles 9a and 9b – Time Interval [53.5, 58.7)

The examples shown above demonstrate the primary types of information that may be authored using DFXP: metadata, styling, layout, timing, and content. In typical cases, styling and layout information are separately specified in a document instance. Content information is expressed in a hierarchical fashion that embodies the organization of both spatial (flow) and timing information. Content makes direct or indirect references to styling and layout information and may specify inline overrides to styling.

2 Definitions

2.1 Acronyms

DFXP	Distribution Format Exchange Profile
TT	Timed Text
TT AS	Timed Text Authoring System
TT AF	Timed Text Authoring Format
TT WG	Timed Text Working Group

2.2 Terminology

Abstract Document Instance: An instance of an abstract data set as represented by a Reduced XML Infoset .
Abstract Document Type: A set of constraints that defines a class of XML Information Set s [XML InfoSet] .
Attribute Information Item: Each specified or defaulted attribute of an XML document corresponds with an attribute information item as defined by [XML InfoSet] , §2.3.
Character Information Item: Each data character appearing in an XML document corresponds with a character information item as defined by [XML InfoSet] , §2.6.
Content Processor: A processing system capable of importing (receiving) timed text authoring format content for the purpose of transforming, presenting, or otherwise processing the content.
Content Profile: A collection of features and extensions that are (or may be) employed by timed text authoring format content.
Content Region: A logical region into which rendered content is placed when modeling or performing presentation processing.
Element Information Item: Each element appearing in an XML document corresponds with an element information item as defined by [XML InfoSet] , §2.2.
Exchange Profile: A content profile that serves a set of needs for content interchange.
Extension: A syntactic or semantic expression or capability that is defined and labeled (using a extension designation) in another (public or private) specification.
Feature: A syntactic or semantic expression or capability that is defined and labeled (using a feature designation) in this specification (or a future revision of this specification).
Processor: See Content Processor .
Processor Profile: A collection of features and extensions that must or may be implemented (supported) by by a content processor.
Profile Definition Document: A document that defines a specific collection of features and extensions for which support is required or optional in a recipient content processor.
Region: A logical construct that models authorial intention regarding desired or potential presentation processing, and which is represented as a rectangular area of a presentation surface into which content is composed and rendered during presentation processing.
Reduced XML Infoset: An XML Information Set [XML InfoSet] that satisfieds the constraints specify by A Reduced XML Infoset .
Root Container Region: A logical region that establishes a coordinate system into which content regions are placed and optionally clipped.
Timed Text: Textual information that is intrinsically or extrinsically associated with timing information.
Timed Text Authoring Format: A content type that represents timed text media for the purpose of interchange among authoring systems.
Timed Text Authoring System: A content authoring system capable of importing and exporting timed text authoring format content.

2.3 Documentation Conventions

Within normative prose in this specification, the words may , should , and must are defined as follows:

may: Conforming documents and/or TT AF processors are permitted to, but need not behave as described.
should: Conforming documents and/or TT AF processors are strongly recommended to, but need not behave as described.
must: Conforming documents and/or TT AF processors are required to behave as described; otherwise, they are in error.

All normative syntactic definitions of XML representations and other related terms are depicted with a light orange background color and labeled as "XML Representation" or "Syntax Representation", such as in the following:

XML Representation – Element Information Item: example
<example count = integer size = (large\|medium\|small) : medium> Content: (all \| any*) </example>

In an XML representation, bold-face attribute names (e.g. count above) indicate a required attribute information item, and the rest are optional. Where an attribute information item has an enumerated type definition, the values are shown separated by vertical bars, as for size above; if there is a default value, it is shown following a colon. Where an attribute information item has a built-in simple type definition defined in [XML Schema Part 2] , a hyperlink to its definition therein is given.

The allowed content of the information item is shown as a grammar fragment, using the Kleene operators ? , * and + . Each element name therein is a hyperlink to its own illustration.

All content of this specification that is not explicitly marked as non-normative is considered to be normative. If a section or appendix header contains the the expression "Non-Normative", then the entirety of the section or appendix is considered non-normative.

All paragraphs marked as a Note are considered non-normative.

Example code fragments are depicted with a light blue-green background color and labeled as "Example Fragment", such as in the following:

Example Fragment – Sample
<tt xml:lang="" xmlns="http://www.w3.org/2006/10/ttaf1"> <head> <metadata/> <styling/> <layout/> </head> <body/> </tt>

3 Conformance

This section specifies the general conformance requirements for TT AF content and processors.

3.1 Content Conformance

A TT AF document instance conforms to this specification if the following criteria are satisfied:

When transporting a document instance in a context in which a MIME Media Type [MIME] identifies the content type of the interchanged document instance, then the specified media type is application/ttaf+xml in conformance with [XML Media Types] § 7, with which an optional profile parameter may appear, the value of which conforms to a profile designator as defined by 5.2 Profiles .
The document instance is or can be represented as a Reduced XML Infoset as defined by A Reduced XML Infoset .
The Reduced XML Infoset that corresponds to the document instance is or can be associated with one of the TT AF Abstract Document Types defined by 4 Document Types .
The Reduced XML Infoset that corresponds to the document instance is a Valid Abstract Document Instance of the associated Abstract Document Type.
The Reduced XML Infoset satisfies all additional mandatory syntactic and semantic constraints defined by this specification. In addition, this Infoset should satisfy the web content accessibility guidelines specified by [WCAG] .

3.2 Processor Conformance

3.2.1 Generic Processor Conformance

A TT AF processor conforms to this specification if the following generic processor criteria are satisfied:

The processor provides at least one mechanism for notionally instantiating a Reduced XML Infoset representation of a conformant TT AF document instance.
If a process does or can perform validation of a candidate TT AF document instance, then it provides at least one mechanism to implicitly or explicitly associate the Reduced XML Infoset representation of a conformant TT AF document instance with one of the TT AF Abstract Document Types defined by 4 Document Types .
The processor does not a priori reject or abort the processing of a conformant TT AF document instance unless the processor does not support some required (mandatory) feature specified or implied by a TT AF content profile declared to apply to the document instance.
The processor supports all mandatory processing semantics defined by this specification.
If the processor supports some optional processing semantics defined by this specification, then it does so in a manner consistent with the defined semantics.

3.2.2 Transformation Processor Conformance

A TT AF processor is a conformant TT AF transformation processor if the following criteria are satisfied:

The processor satisfies all requirements specified by 3.2.1 Generic Processor Conformance .
The processor supports the DFXP Transformation profile as specified by G.1 DFXP Transformation Profile .

3.2.3 Presentation Processor Conformance

The processor satisfies all requirements specified by 3.2.1 Generic Processor Conformance .
The processor supports the DFXP Presentation profile as specified by G.2 DFXP Presentation Profile .

3.3 Claims

Any claim of compliance with respect to TT AF content or processor conformance must make reference to an implementation compliance statement (ICS).

An implementation compliance statement must identify all mandatory and optional features of this specification that are satisfied by the content or processor implementation. In particular, the statement must identify the utilized or supported TT AF vocabulary profile(s) as defined by 5.2 Profiles , and, if a subset or superset profile is used or supported, then what features are excluded or included in the subset or superset profile.

A TT AF document instance for which a compliance claim is made must specify either (1) a ttp:profile attribute on its root tt element as defined by ~~6.2.7~~ 6.2.8 ttp:profile or (2) a ttp:profile element as a child of the head element as defined by 6.1.1 ttp:profile .

4 Document Types

This section defines the following TT AF Abstract Document Types:

4.1 DFXP Content

Each abstract document type consists of the following constraints:

a non-empty collection of element types, where each element type consists of a name, a (possibly empty) collection of attributes, and a content specification
a non-empty collection of element types that may appear as the document element

An Abstract Document Instance may be assessed in terms of validity, and is considered to be a Valid Abstract Document Instance if it satisfies the following condition: if after

pruning all element information items whose names are not members of the collection of element types defined by the associated abstract document type, then
pruning character information item children from any remaining element in case that all character children of the element denote XML whitespace characters and the element's type is defined as empty in the associated Abstract Document Type, and then
pruning all attribute information items having expanded names such that the namespace URI of the expanded names are not listed in Table 1 – Namespaces ,

then the document element is one of the document element types permitted by the associated abstract document type, the descendants of the document element satisfy their respective element type's content specifications, all required attributes are present, and the declared value of each attribute satisfies the type declared by the associated abstract document type.

Note:

While a conformant processor may not a priori reject a conformant document instance that adheres to a supported content profile, a given document instance may be constrained by the author or authoring tool to satisfy a more restrictive definition of validity.

4.1 DFXP Content

DFXP Content is an abstract document type of the Timed Text Authoring Format intended to be used for interchange among distribution systems. This document type is defined in terms of the element and attribute vocabulary specified in 5 Vocabulary .

This specification defines two types of normative schemas that may be used to validate a subset of conformant DFXP document instances:

C.1 Relax NG Schema
C.2 XML Schema Definition (XSD) Schema

The (root) document element of a DFXP document instance must be a tt element, as defined by 7.1.1 tt .

Note:

The schemas included in this specification do not validate all syntactic constraints defined by this specification. In particular, performing validation with one of the above referenced schemas may result in a false positive indication of validity. However, with one exception, their use will not produce a false negative indication of validity when used with a compliant validating processor.

In exception to the above statement about false negatives, if the Relax NG schema included in this specification is used to validate a TT AF Document containing elements in a foreign namespace and the xml:id attribute is used with any of those (foreign) elements, then an error will be reported even though such usage is permitted by this specification. In this case, the false negative arises due to a specific limitation in expressing wildcard patterns involving xsd:ID typed attributes in Relax NG schemas. Note that this specification defines the formal validity of a TT AF Document to be based on an abstract document instance from which all foreign namespace elements and attributes have been removed. Therefore, the exceptional reporting of this false negative does not impact the formal assessment of TT AF Document validity.

5 Vocabulary

This section defines the namespaces, profiles, and vocabulary (as an element an attribute catalog) of the Timed Text Authoring Format (TT AF) as follows:

5.1 Namespaces
5.2 Profiles
5.3 Catalog

5.1 Namespaces

The Timed Text Authoring Format (TT AF) employs a number of namespaces for elements and certain global attributes. The following table specifies this set of namespaces and indicates the default prefix used within this specification and the normative URI that denotes each namespace.

Note:

In a specific document instance, it is not required that the default prefixes shown below are used. Any prefix or namespace binding that satisfies the constraints of XML Namespaces may be used that is associated with the specified namespace URI.

Table 1 – Namespaces
Name	Prefix	Value
TT	`tt:`	`http://www.w3.org/2006/10/ttaf1`
TT Parameter	`ttp:`	`http://www.w3.org/2006/10/ttaf1#parameter`
TT Style	`tts:`	`http://www.w3.org/2006/10/ttaf1#styling`
TT Metadata	`ttm:`	`http://www.w3.org/2006/10/ttaf1#metadata`
TT Profile	none	`http://www.w3.org/2006/10/ttaf1/profile /`
TT Feature	none	`http://www.w3.org/2006/10/ttaf1/feature /`
TT Extension	none	`http://www.w3.org/2006/10/ttaf1/extension /`

Note:

If a reference to an element type is used in this specification and the name of the element type is not namespace qualified, then the TT Namespace applies.

For certain namespaces defined above, the default prefix is specified as none if no XML vocabulary is defined in the namespace by this specification (nor expected to be defined in a future version of this specification). In such cases, the use of the namespace URI is for purposes other than defining XML vocabulary, e.g., for designating profiles, features, extensions and for dereferencing standard profile definitions.

All TT AF Namespaces are mutable [NSState] ; all undefined names in these namespaces are reserved for future standardization by the W3C.

5.2 Profiles

The Timed Text Authoring Format (TT AF) employs a number of standard, predefined profiles of its vocabulary and associated semantics. The following table specifies this set of profiles, indicating a normative name and designator for each predefined profile, and where each of these profiles is formally elaborated in G Profiles .

Table 2 – Profiles
Name	Designator
DFXP Transformation	`http://www.w3.org/2006/10/ttaf1/profile/dfxp-transformation`
DFXP Presentation	`http://www.w3.org/2006/10/ttaf1/profile/dfxp-presentation`
DFXP Full	`http://www.w3.org/2006/10/ttaf1/profile/dfxp-full`

A profile designator must adhere to the xsd:anyURI data type defined by [XML Schema Part 2] , §3.2.17. If the profile designator is expressed as a relative URI, then it must be absolutized by using the TT Profile Namespace value as the base URI.

Note:

For example, if a profile designator is expressed as dfxp-presentation , then the absolutized profile designator would be http://www.w3.org/2006/10/ttaf1/profile/dfxp-presentation .

A profile designator is not restricted to the set of designators enumerated in Table 2 – Profiles , but may be any URI that feasibly dereferences a TT AF Profile Definition Document.

The profile of TT AF that must be supported by a TT AF content processor in order to process a document instance is specified either (1) by specifying a ttp:profile attribute on the root tt element, as defined by ~~6.2.7~~ 6.2.8 ttp:profile , or (2) by including one or more ttp:profile elements in the head element, in accordance with 6.1.1 ttp:profile .

If a ttp:profile element appears as a descendant of the tt element, then the ttp:profile attribute should not be specified on the tt element. If both a ttp:profile element and a ttp:profile attribute are present (in a given document instance), then the ttp:profile attribute must be ignored for the purpose of determining the declared profile requirements.

If more than one ttp:profile element appears in a TT AF document instance, then all specified profiles apply simultaneously. In such a case, if some feature or some extension is specified by one profile to be used (mandatory and enabled) and by another profile to be required (mandatory) or optional (voluntary), then that feature or extension must be considered to be used (mandatory and enabled); if some feature or some extension is specified by one profile to be merely required (mandatory) and by another profile to be optional (voluntary), then that feature or extension must be considered to be required (mandatory).

If neither ttp:profile attribute nor ttp:profile element is present in a TT AF document instance, and if the document interchange context does not specify a profile, then the DFXP Transformation profile applies.

Note:

It is intended that the ttp:profile attribute be used when the author wishes to reference one of the standard, predefined profiles of TT AF content, and does not wish to modify (by supersetting or subsetting) that profile. This attribute may also be used by an author to indicate the use of a non-standard profile, in which case the specified profile designator expresses a URI that denotes an externally defined TT AF Profile Definition Document. However, it is not required that a conformant TT AF content processor be able to dereference such an externally specified profile definition.

In contrast, it is intended that the ttp:profile element be used when the author wishes to make use of a modified predefined profile or wishes to include in the document instance a non-standard profile definition not based upon one of the predefined profiles.

A predefined profile is supersetted by specifying some feature or extension to be required (mandatory) that was either not specified in the underlying, baseline profile or was specified as optional (voluntary) in the baseline profile. A predefined profile is subsetted by specifying some feature or extension to be optional (voluntary) that was specified as required in the underlying, baseline profile.

When a baseline profile is modified by subsetting, the resulting, derived profile is referred to as a subtractive profile; when modified by supersetting, the result is referred to as an additive profile. It is also possible to define a derived profile that is simultaneously subtractive and additive.

If a TT AF document instance makes use of a feature defined by E.1 Feature Designations and if the intended use of the document requires the recognition and processing of that feature, then the document must include a required feature or a used feature specification in one of its declared or referenced profiles. If a TT AF document instance makes use of an extension designatable by F.1 Extension Designations and if the intended use of the document requires the recognition and processing of that extension, then the document must include a required extension or a used extension specification in one of its declared or referenced profiles.

Note:

A required or used feature specification is expressed directly (or indirectly by referring to a profile) by means of a ttp:feature element where the value of its value attribute is required or use , respectively. A required or used extension specification is expressed directly (or indirectly by referring to a profile) by means of a ttp:extension element where the value of its value attribute is required or use , respectively.

An example of an author defined additive, derived profile of the DFXP Presentation profile is shown below in Example Fragment – DFXP Additive Profile .

Example Fragment – DFXP Additive Profile
<tt xml:lang="" xmlns="http://www.w3.org/2006/10/ttaf1"> <head> <profile use="dfxp-presentation" xmlns="http://www.w3.org/2006/10/ttaf1#parameter"> ~~<features xml:base="http://www.w3.org/2006/10/ttaf1/feature">~~ <features xml:base="http://www.w3.org/2006/10/ttaf1/feature/"> <feature value="required">#fontStyle-italic</feature> </features> </profile> </head> <body/> </tt>

Example Fragment – DFXP Additive Profile

<tt xml:lang="" xmlns="http://www.w3.org/2006/10/ttaf1">
 <head>
   <profile use="dfxp-presentation" xmlns="http://www.w3.org/2006/10/ttaf1#parameter">
     <features xml:base="http://www.w3.org/2006/10/ttaf1/feature">

     <features xml:base="http://www.w3.org/2006/10/ttaf1/feature/">

       <feature value="required">#fontStyle-italic</feature>
     </features>
   </profile>
 </head>
 <body/>
</tt>

Note:

In the above example, the baseline profile is declared to be the DFXP Presentation profile, which is then additively modified by making the #fontStyle-italic feature required (rather than optional as it is defined in G.2 DFXP Presentation Profile ). Note also the resetting of the default XMLNS binding on the profile element to the TT Parameter Namespace.

5.3 Catalog

The vocabulary of the Timed Text Authoring Format (TT AF) is defined in the following major catalogs (divisions of vocabulary):

5.3.1 Core Catalog
5.3.2 Extension Catalog

The core catalog defines the baseline, core vocabulary of the TT AF, and, in particular, the vocabulary of DFXP. The extension catalog serves as a placeholder for extensions to the core vocabulary defined by DFXP.

5.3.1 Core Catalog

The core vocabulary catalog is intended to satisfy the needs of DFXP while providing a baseline vocabulary for future profiles. This vocabulary is divided into distinct categories, specified in detail in the following sections:

6 Parameters
7 Content
8 Styling
9 Layout
10 Timing
11 Animation
12 Metadata

The core element vocabulary specified for use with a TT AF document instance is enumerated in Table 3 – Element Vocabulary .

Table 3 – Element Vocabulary
Module	Elements
Animation	set
Content	body , div , p , span , br
Document	tt
Head	head
Layout	layout , region
Metadata	metadata
Metadata Items	ttm:actor , ttm:agent , ttm:copyright , ttm:desc , ttm:name , ttm:title
Parameter Items	ttp:profile , ttp:features , ttp:feature , ttp:extensions , ttp:extension
Styling	styling , style

Element vocabulary groups that are used in defining content models for TT AF element types are enumerated in Table 4 – Element Vocabulary Groups .

Table 4 – Element Vocabulary Groups
Group	Elements
Animation.class	set
Block.class	div \| p
Inline.class	span \| br \| `#PCDATA`
Metadata.class	metadata \| ttm:agent \| ttm:copyright \| ttm:desc \| ttm:title
Parameters.class	ttp:profile

The attribute vocabulary specified for use with the core vocabulary catalog is enumerated in Table 5 – Attribute Vocabulary .

Table 5 – Attribute Vocabulary
Module	Attributes
Core Attributes	xml:id , xml:lang , xml:space
Layout	region
Metadata Attributes	ttm:agent , ttm:role
Parameter Attributes	ttp:cellResolution , ttp:clockMode , ttp: dropMode , ttp:frameRate , ttp:frameRateMultipler , ttp:markerMode , ttp:pixelAspectRatio , ttp:profile , ~~ttp:smpteMode ,~~ ttp:subFrameRate , ttp:tickRate , ttp:timeBase
Styling	style
Styling Attributes	tts:backgroundColor , tts:color , tts:direction , tts:display , tts:displayAlign , tts:dynamicFlow , tts:extent , tts:fontFamily , tts:fontSize , tts:fontStyle , tts:fontWeight , tts:lineHeight , tts:opacity , tts:origin , tts:overflow , tts:padding , tts:showBackground , tts:textAlign , tts:textDecoration , tts:textOutline , tts:unicodeBidi , tts:visibility , tts:wrapOption , tts:writingMode , tts:zIndex
Timing Attributes	begin , dur , end , timeContainer

Note:

Only those attributes defined as either (1) global, i.e., namespace qualified, or (2) shared element-specific, i.e., not namespace qualified but shared across multiple element types, are listed in Table 5 – Attribute Vocabulary above.

Note:

All vocabulary defined by the TT AF consistently makes use of the so-called lowerCamelCase naming convention. In some cases, this results in the change of a name when the name was based upon another specification that used a different naming convention.

5.3.2 Extension Catalog

The extension vocabulary catalog is intended for use by future profiles of the TT AF, and is not further defined by this version of this specification.

In addition to standardized extension vocabulary, a conforming TT AF document instance may contain arbitrary namespace qualified elements that reside in any namespace other than those namespaces defined for use with this specification. Furthermore, a conforming TT AF document instance may contain arbitrary namespace qualified attributes on TT AF defined vocabulary where such attributes reside in any namespace other than those defined for use with this specification.

6 Parameters

This section specifies the parameters matter of the core vocabulary catalog, where parameters are to be understood as information that is either (1) essential or (2) of significant importance for the purpose of interpreting the semantics of other types of information expressed by core vocabulary items or for establishing a processing context by means of which TT AF content can be related to an external environment.

6.1 Parameter Element Vocabulary

The following elements, all defined in the TT Parameter Namespace, specify parametric information that applies to a document or a content processor:

6.1.1 ttp:profile
6.1.2 ttp:features
6.1.3 ttp:feature
6.1.4 ttp:extensions
6.1.5 ttp:extension

6.1.1 ttp:profile

The ttp:profile element is used to specify a collection of used (mandatory and enabled), required (mandatory), and optional (voluntary) features and extensions that must or may be supported by a TT AF content processor in order to process a TT AF document that makes use (or may make use) of such features and extensions.

Note:

The difference between a feature and an extension is where it is defined an d how it is labeled: if defined in this specification (or a future revision thereof) and labeled with a feature designation in E Features , then it is considered to be a feature; if defined in another specification and labeled there with an extension designation, then it is considered to be an extension. In general, features are expected to be defined by the W3C standards process, while extensions are expected to be defined by third parties.

This specification defines two distinct uses of the ttp:profile element:

as a child of the head element within a TT AF document instance;
as the root element of a TT AF Profile Definition document instance;

When a tt:profile element appears within a TT AF document instance, its purpose is to express authorial intentions about which features and extensions must or may be supported by a recipient content processor. In addition, the element indirectly expresses information about the set of features or extensions that are (or may expected to be) used by the document instance.

When a tt:profile element is used by a TT AF Profile Definition document instance, it serves to publish a machine readable specification of a specific TT AF content profile, of which this specification defines four such Profile Definition Documents in G Profiles .

The ttp:profile element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more ttp:features elements, followed by zero or more ttp:extensions elements.

XML Representation – Element Information Item: ttp:profile
<ttp:profile use = string xml:id = ID {any attribute not in default or any TT namespace}> Content: Metadata.class, ttp:features, ttp:extensions* </ttp:profile>

If specified, the use attribute must adhere to the xsd:anyURI data type defined by [XML Schema Part 2] , §3.2.17, and, furthermore, must denote a profile designator in accordance with 5.2 Profiles . In this case, the profile designator must refer to (1) a standard, predefined TT AF Profile Definition Document as defined by G Profiles , or (2) a dereferenceable resource representing a valid TT AF Profile Definition document instance. In either case, the referenced profile serves as the baseline profile of the specifying ttp:profile element.

If the use attribute is not specified, then the baseline profile of the ttp:profile element must be considered to be the empty (null) profile, i.e., a profile definition containing no feature or extension specifications.

The collection of features and extensions of a profile are determined according to the following ordered rules:

initialize the features and extensions of the profile to the empty set;
if a use attribute is present, then augment the profile with the set of features and extensions specified by the referenced baseline profile;
for each ttp:feature and ttp:extension element descendant of the ttp:profile element, using a post-order traversal, merge the specified feature or extension with the features and extensions of the profile, where merging a feature or extension entails replacing an existing feature or extension specification, if it already exists, or adding a new feature or extension specification, if it does not yet exist in the profile;

A conformant TT AF processor is not required to be able to dereference a TT AF Profile Definition Document that is not one of the standard, predefined profiles defined by G Profiles . A conformant TT AF processor may make use of a built-in, static form of each standard, predefined profile so as not to require dereferencing a network resource.

If a TT AF processor is unable to dereference a non-standard TT AF Profile Definition Document, then it must not further process the document without the presence of an explicit override from an end-user or some implementation specific parameter traceable to an end-user or to a user or system configuration setting. If a TT AF processor aborts processing of a TT AF document instance due to the inability to reference a non-standard TT AF Profile Definition Document, then some end-user notification should be given unless the end-user or system has disabled such a notification, or if the processor does not permit or entail the intervention of an end-user.

The ttp:profile element is illustrated by the following example.

Example Fragment – ttp:profile
<ttp:profile use="dfxp-presentation"> ~~<ttp:features xml:base="http://www.w3.org/2006/10/ttaf1/feature">~~ <ttp:features xml:base="http://www.w3.org/2006/10/ttaf1/feature/"> <ttp:feature>#rollUp</ttp:feature> </ttp:features> </ttp:profile>

Example Fragment – ttp:profile

<ttp:profile use="dfxp-presentation">
  <ttp:features xml:base="http://www.w3.org/2006/10/ttaf1/feature">

  <ttp:features xml:base="http://www.w3.org/2006/10/ttaf1/feature/">

    <ttp:feature>#rollUp</ttp:feature>
  </ttp:features>
</ttp:profile>

Note:

In the above example, the DFXP presentation profile is used as the baseline profile. This baseline profile is then supersetted (thus creating an additive derived profile) by requiring support for #rollUp feature.

6.1.2 ttp:features

The ttp:features element is a container element used to group infomation about feature support requirements.

The ttp:features element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more ttp:feature elements.

XML Representation – Element Information Item: ttp:features
<ttp:features xml:base = string : TT Feature Namespace xml:id = ID {any attribute not in default or any TT namespace}> Content: Metadata.class, ttp:feature </ttp:features>

If specified, the xml:base attribute must (1) adhere to the xsd:anyURI data type defined by [XML Schema Part 2] , §3.2.17, (2) express an absolute URI that adheres to [XML Base] and, (3) express a feature namespace as defined by E.1 Feature Designations . If not specified, the xml:base attribute's default value applies, which is the TT Feature Namespace.

The xml:base attribute is used to permit the abbreviation of feature designation URIs expressed by child ttp:feature elements.

6.1.3 ttp:feature

The ttp:feature element is used to specify infomation about support requirements for a particular feature.

The children of the ttp:feature element must express a non-empty sequence of character information items that adheres to the xsd:anyURI data type defined by [XML Schema Part 2] , §3.2.17.

XML Representation – Element Information Item: ttp:feature
<ttp:feature value = (optional\|required\|use) : required xml:id = ID {any attribute not in default or any TT namespace}> Content: #PCDATA </ttp:feature>

If the URI expressed by the content of the ttp:feature element is a relative URI, then, when combined with the feature namespace value expressed by the xml:base attribute of the nearest ancestor ttp:features element, it must express an absolute URI. In either case (original absolute URI or resulting absolutized URI), the URI expressed by the ttp:feature element must further adhere to the syntax of a feature designation as defined by E.1 Feature Designations .

If the URI expressed by the content of the ttp:feature element is a relative URI, then an xml:base attribute should be specified on the nearest ancestor ttp:features element.

The value attribute specifies whether a conforming TT AF processor must or may implement the designated feature in order to process the document. If the value of the value attribute is optional , then the processor need not implement or otherwise support the feature in order to process the document; if the value is required , then the processor must implement or otherwise support the feature in order to process the document; if the value is use , then the processor must both (1) implement or otherwise support the feature and (2) enable (activate) use of the feature.

Note:

The default value of the value attribute is required , as indicated in the above element information item definition. Therefore, if a value attribute is not specified on a ttp:feature element, it is equivalent to specifying that support for the feature is required.

If the value of the value attribute is required or use , and if the TT AF processor implementation does not support the feature, then it must not further process the document without the presence of an explicit override from an end-user or some implementation specific parameter traceable to an end-user or to a user or system configuration setting. If a TT AF processor aborts processing of a TT AF document instance due to the specification of a required, but unsupported feature by this element, then some end-user notification should be given unless the end-user or system has disabled such a notification, or if the processor does not permit or entail the intervention of an end-user.

If the value of the value attribute is optional , and if the TT AF processor implementation does not support the feature, then it may further process the document even in the case that some use of the feature is present in the document. In the case of actual use of a feature designated as optional, the default semantics associated with that feature apply; that is, the processor may behave as if the feature were not actually used or referenced by the document. Notwithstanding the above, the syntactic presence or reference to an optional feature by a document must not be considered to be a violation of document validity or a barrier to further processing if the syntactic expression is well-formed and valid.

The ttp:feature element is illustrated by the following example.

Example Fragment – ttp:feature
<ttp:profile use="http://www.w3.org/2006/10/ttaf1/profile/dfxp-presentation"> ~~<ttp:features xml:base="http://www.w3.org/2006/10/ttaf1/feature">~~ <ttp:features xml:base="http://www.w3.org/2006/10/ttaf1/feature/"> <ttp:feature value="required">#fontStyle-italic</ttp:feature> <ttp:feature value="required">#textDecoration-under</ttp:feature> </ttp:features> </ttp:profile>

Example Fragment – ttp:feature

<ttp:profile use="http://www.w3.org/2006/10/ttaf1/profile/dfxp-presentation">
  <ttp:features xml:base="http://www.w3.org/2006/10/ttaf1/feature">

  <ttp:features xml:base="http://www.w3.org/2006/10/ttaf1/feature/">

    <ttp:feature value="required">#fontStyle-italic</ttp:feature>
    <ttp:feature value="required">#textDecoration-under</ttp:feature>
  </ttp:features>
</ttp:profile>

Note:

In the above example, the DFXP presentation profile is used as the baseline profile. This baseline profile is then modified by two ttp:feature elements in order to superset the baseline profile (since neither #fontStyle-italic nor #textDecoration-under are required by the DFXP presentation profile). Note that the explicit specification of required on the value attribute on these two ttp:feature elements is not strictly necessary, since it is the default value of this attribute.

The effect of this example is to express authorial intentions that italic font style and text underlining must be supported.

6.1.4 ttp:extensions

The ttp:extensions element is a container element used to group infomation about extension support requirements.

The ttp:extensions element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more ttp:extension elements.

XML Representation – Element Information Item: ttp:extensions
<ttp:extensions xml:base = string : TT Extension Namespace xml:id = ID {any attribute not in default or any TT namespace}> Content: Metadata.class, ttp:extension </ttp:extensions>

If specified, the xml:base attribute must (1) adhere to the xsd:anyURI data type defined by [XML Schema Part 2] , §3.2.17, (2) express an absolute URI that adheres to [XML Base] and, (3) express an extension namespace as defined by F.1 Extension Designations . If not specified, the xml:base attribute's default value applies, which is the TT Extension Namespace.

The xml:base attribute is used to permit the abbreviation of feature designation URIs expressed by child ttp:extension elements.

6.1.5 ttp:extension

The ttp:extension element is used to specify infomation about support requirements for a particular extension.

The children of the ttp:extension element must express a non-empty sequence of character information items that adheres to the xsd:anyURI data type defined by [XML Schema Part 2] , §3.2.17.

XML Representation – Element Information Item: ttp:extension
<ttp:extension value = (optional\|required\|use) : required xml:id = ID {any attribute not in default or any TT namespace}> Content: #PCDATA </ttp:extension>

If the URI expressed by the content of the ttp:extension element is a relative URI, then, when combined with the extension namespace value expressed by the xml:base attribute of the nearest ancestor ttp:extensions element, it must express an absolute URI. In either case (original absolute URI or resulting absolutized URI), the URI expressed by the ttp:extension element must further adhere to the syntax of an extension designation as defined by F.1 Extension Designations .

If the URI expressed by the content of the ttp:feature element is a relative URI, then an xml:base attribute should be specified on the nearest ancestor ttp:extensions element.

The value attribute specifies whether a conforming TT AF processor must or may implement the designated extension in order to process the document. If the value of the value attribute is optional , then the processor need not implement or otherwise support the extension in order to process the document; if the value is required , then the processor must implement or otherwise support the extension in order to process the document; if the value is use , then the processor must both (1) implement or otherwise support the extension and (2) enable (activate) use of the extension.

Note:

The default value of the value attribute is required , as indicated in the above element information item definition. Therefore, if a value attribute is not specified on a ttp:extension element, it is equivalent to specifying that support for the extension is required.

If the value of the value attribute is required or use , and if the TT AF processor implementation does not support the extension, then it must not further process the document without the presence of an explicit override from an end-user or some implementation specific parameter traceable to an end-user or to a user or system configuration setting. If a TT AF processor aborts processing of a TT AF document instance due to the specification of a required, but unsupported extension by this element, then some end-user notification should be given unless the end-user or system has disabled such a notification, or if the processor does not permit or entail the intervention of an end-user.

If the value of the value attribute is optional , and if the TT AF processor implementation does not support the extension, then it may further process the document even in the case that some use of the extension is present in the document. In the case of actual use of an extension designated as optional, the default semantics associated with that extension apply; that is, the processor may behave as if the extension were not actually used or referenced by the document. Notwithstanding the above, the syntactic presence or reference to an optional extension by a document must not be considered to be a violation of document validity or a barrier to further processing if the syntactic expression is well-formed and valid.

The ttp:extension element is illustrated by the following example.

Example Fragment – ttp:extension
<ttp:profile use="http://www.w3.org/2006/10/ttaf1/profile/dfxp-transformation"> ~~<ttp:extensions xml:base="http://foo.bar.example.org/ttaf1/extension">~~ <ttp:extensions xml:base="http://foo.bar.example.org/ttaf1/extension/"> <ttp:extension value="use">#prefilter-by-language</ttp:extension> </ttp:extensions> </ttp:profile>

Example Fragment – ttp:extension

<ttp:profile use="http://www.w3.org/2006/10/ttaf1/profile/dfxp-transformation">
  <ttp:extensions xml:base="http://foo.bar.example.org/ttaf1/extension">

  <ttp:extensions xml:base="http://foo.bar.example.org/ttaf1/extension/">

    <ttp:extension value="use">#prefilter-by-language</ttp:extension>
  </ttp:extensions>
</ttp:profile>

Note:

In the above example, the DFXP transformation profile is used as the baseline profile. This baseline profile is then supersetted by specifying that support and use is required for a private extension defined in a third party namespace.

The effect of this example is to express authorial intentions that a recipient processor must support the DFXP transformation profile and must also support and use an extension defined by a third party.

6.2 Parameter Attribute Vocabulary

The following attributes are defined in the TT Parameter Namespace.

6.2.1 ttp:cellResolution
6.2.2 ttp:clockMode
6.2.3 ~~ttp:frameRate~~ ttp:dropMode
6.2.4 ~~ttp:frameRateMultiplier~~ ttp:frameRate
6.2.5 ~~ttp:markerMode~~ ttp:frameRateMultiplier
6.2.6 ~~ttp:pixelAspectRatio~~ ttp:markerMode
6.2.7 ~~ttp:profile~~ ttp:pixelAspectRatio
6.2.8 ~~ttp:smpteMode~~ ttp:profile
6.2.9 ttp:subFrameRate
6.2.10 ttp:tickRate
6.2.11 ttp:timeBase

Unless explicitly stated otherwise, linear white-space (LWSP) may appear between tokens of a value of a TT Parameter.

6.2.1 ttp:cellResolution

The ttp:cellResolution attribute may be used by an author to express the number of horizontal and vertical cells into which the root container region area is divided for the purpose of expressing presentation semantics in terms of a uniform grid.

If specified, the value of this attribute must adhere to the following syntax:

Syntax Representation – ttp:cellResolution
ttp:cellResolution : columns rows // columns != 0; rows != 0 columns \| rows : <digit>+

If not specified, the number of columns and rows must be considered to be 32 and 15, respectively. If specified, then columns or rows must not be zero (0).

Note:

The choice of values 32 and 15 are based on this being the maximum number of columns and rows defined by [CEA-608-C] .

A ttp:cellResolution attribute is considered to be significant only when specified on the tt element.

Note:

The use of a uniform grid is employed only for the purpose of measuring lengths and expressing coordinates. In particular, it is not assumed that the presentation of text or the alignment of individual glyph areas is coordinated with this grid. Such alignment is possible, but requires the use of a monospaced font and a font size whose EM square exactly matches the cell size.

6.2.2 ttp:clockMode

The ttp:clockMode attribute is used to specify the interpretation of time expressions as real-time time coordinates when operating with time base of clock as defined by 6.2.11 ttp:timeBase .

Note:

See 10.3 Time Value Expressions for the specification of time expression syntax.

If specified, the value of this attribute must adhere to the following syntax:

Syntax Representation – ttp:clockMode
ttp:clockMode : "local" \| "gps" \| "utc"

If the time base, defined by 6.2.11 ttp:timeBase , is designated as clock , then this parameter applies as follows: if the parameter's value is local , then time expressions are interpreted as local wall-clock time coordinates; if utc , then time expressions are interpreted as UTC time coordinates [UTC] ; if gps , then time expressions are interpreted as GPS time coordinates [GPS] .

Note:

The primary difference between GPS time and UTC time is that GPS time is not adjusted for leap seconds, while UTC time is adjusted as follows: UTC = TAI ( Temp Atomique International ) + leap seconds accumulated since 1972 . TAI is maintained by the Bureau International des Poids et Mesures (BIPM) in Sevres, France. The GPS system time is steered to a Master Clock (MC) at the US Naval Observatory which is kept within a close but unspecified tolerance of TAI.

If not specified, the value of this parameter must be considered to be utc .

A ttp:clockMode attribute is considered to be significant only when specified on the tt element.

6.2.3 ttp: dropMode

The ttp: dropMode attribute is used to specify constraints on the interpretation and use of frame counts that correspond with [SMPTE 12M] time coordinates when operating with time base of smpte as defined by 6.2.11 ttp:timeBase .

If specified, the value of this attribute must adhere to the following syntax:

Syntax Representation – ttp: dropMode
ttp:dropMode : "dropNTSC" \| "dropPAL" \| "nonDrop"

If the time base, defined by 6.2.11 ttp:timeBase ,is designated as smpte ,then this parameter applies as follows: if the parameter's value is nonDrop ,then, within any given second of a time expression, frames count from 0 to N−1 ,where N is the value specified by the ttp:frameRate parameter, but while ignoring any value specified by the ttp:frameRateMultiplier parameter.

Note:

When operating in nonDrop mode, a second of a time expression may or may not be equal to a second of real time during normal (1x speed) forward playback. If the ttp:frameRateMultiplier parameter is specified and is not equal to 1:1, then a second of a time expression will either be shorter or longer than a second of elapsed play in real time.

If this parameter's value is dropNTSC ,then, within any given second of a time expression except the second 00 ,frames count from 0 to N−1 ,where N is the value specified by the ttp:frameRate parameter, but while ignoring any value specified by the ttp:frameRateMultiplier parameter. If the second of a time expression is 00 and the minute of the time expression is not 00 ,10 ,20 ,30 ,40 ,or 50 ,then frame codes 00 and 01 are dropped during that second; otherwise, these frame codes are not dropped.

Note:

For example, when operating in dropNTSC mode with ttp:frameRate of 30 ,a discontinuity in frame count occurs between consecutive frames as shown in the following sequence of time expressions: 01:08:59:28 ,01:08:59:29 ,01:09:00:02 ,01:09:00:03 .

If this parameter's value is dropPAL ,then, within any given second of a time expression except the second 00 ,frames count from 0 to N−1 ,where N is the value specified by the ttp:frameRate parameter, but while ignoring any value specified by the ttp:frameRateMultiplier parameter. If the second of a time expression is 00 and the minute of the time expression is even but not 00 ,20 ,or 40 ,then frame codes 00 through 03 are dropped during that second; otherwise, these frame codes are not dropped.

Note:

For example, when operating in dropPAL mode with ttp:frameRate of 30 ,a discontinuity in frame count occurs between consecutive frames as shown in the following sequence of time expressions: 01:09:59:28 ,01:09:59:29 ,01:10:00:04 ,01:10:00:04 .

Note:

The dropPAL mode is also known as the M/PAL or PAL (M) drop-frame code, which uses PAL modulation with the NTSC frame rate of ~29.97 frames/second. The M/PAL system is used primarily in Brazil.

If not specified, then nonDrop must be assumed to apply.

A ttp: dropMode attribute is considered to be significant only when specified on the tt element.

6.2.4 ttp:frameRate

The ttp:frameRate attribute is used to specify the frame rate of a related media object or the intrinsic frame rate of a document instance in case it is intended to function as an independent media object.

If specified, the value of this attribute must adhere to the following syntax:

Syntax Representation – ttp:frameRate
ttp:frameRate : <digit>+ // value > 0

The frame rate that applies to a document instance is used to interpret time expressions that are expressed in frames as defined by 10.3.1 <timeExpression> .

A frame is interpreted as a division of a second of media time, such that if the frame rate is specified as F , then a second of media time is divided into F intervals of equal duration, where each interval is labeled as frame f , with f ∈ [0… F−1 ].

If not specified, the frame rate must be considered to be equal to some application defined frame rate, or if no application defined frame rate applies, then thirty (30) frames per second. If specified, then the frame rate must be greater than zero (0).

A ttp:frameRate attribute is considered to be significant only when specified on the tt element.

6.2.4 6.2.5 ttp:frameRateMultiplier

The ttp:frameRateMultiplier attribute is used to specify a multiplier to be applied to the frame rate specified by a ttp:frameRate attribute in order to compute the effective frame rate.

If specified, the value of this attribute must adhere to the following syntax:

Syntax Representation – ttp:frameRateMultiplier
ttp:frameRateMultiplier ~~: numerator ( ":" denominator )? // != 0~~ : numerator denominator // numerator != 0; denominator != 0 numerator \| denominator : <digit>+

A frame rate multiplier is used when the desired frame rate cannot be expressed as an integral number of frames per second.

If not specified, the frame rate multiplier must be considered to be equal to one (1:1). ~~If a~~ Both numerator and denominator ~~is specified, then it~~ must ~~not~~ be ~~zero (0). If no denominator is specified, then a denominator of one (1) applies.~~ non-zero.

A ttp:frameRateMultiplier attribute is considered to be significant only when specified on the tt element.

Note:

The frame rate multiplier used for synchronizing with NTSC [SMPTE 170M] formatted video objects at 30 frames per second is nominally 1000:1001. The nominal frame rate of NTSC video is defined as the chrominance sub-carrier frequency of 3,579,545.45…Hz (= 5.0MHz × 63/88) times the ratio 2/455 divided by the number of horizontal lines per frame of 525, which yields a frame rate of 29.970029970029… (= 30 × 1000/1001) frames per second. Other frame rate multipliers apply to different regions of usage and video format standards.

Note:

Except in the case of PAL/M, the frame rate multiplier used for synchronizing with PAL formatted video objects at 25 frames per second is nominally 1:1.

6.2.5 6.2.6 ttp:markerMode

The ttp:markerMode attribute is used to specify constraints on the interpretation and use of time expressions that correspond with [SMPTE 12M] time coordinates when operating with time base of smpte as defined by 6.2.11 ttp:timeBase .

If specified, the value of this attribute must adhere to the following syntax:

Syntax Representation – ttp:markerMode
ttp:markerMode : "continuous" \| "discontinuous"

If the time base, defined by 6.2.11 ttp:timeBase , is designated as smpte , then this parameter applies as follows: if the parameter's value is continuous , then [SMPTE 12M] time coordinates may be assumed to be linear and either monotonically increasing or decreasing; however, if discontinuous , then any assumption must not be made regarding linearity or monotonicity of time coordinates.

If not specified, the value of this parameter must be considered to be continuous .

A ttp:markerMode attribute is considered to be significant only when specified on the tt element.

If a value of discontinuous applies, then time expressions must not be converted to either media time or real time coordinates, arithmetical operators (addition, multiplication) are not defined on time expressions, and, consequently, any expression of a duration must be ~~ignored.~~ considered to be invalid .

Note:

When operating with smpte time base and discontinuous marker mode, there is no effective time coordinate space; rather, all time expressions are interpreted as labeled synchronization events (markers), where some external synchronization context emits these events, which, when they correspond with time expressions that denote the same label, cause a temporal interval to begin or end accordingly.

An additional side-effect of operating in discontinuous mode is that time expressions of children have no necessary relationship with time expressions of their temporal container; that is, temporal containers and children of these containers are temporally activated and inactivated independently based on the occurrence of a labeled synchronization (marker) event.

Note:

The notion of marker discontinuity as captured by this parameter is logically independent from the method used to count frames as expressed by the ttp:smpteMode ttp: dropMode parameter. In particular, even if the ttp:smpteMode ttp: dropMode parameter is specified as dropNTSC or dropPAL , the marker mode may be specified as continuous , even in the presence of frame count discontinuities induced by the frame counting method, unless there were some other non-linearity or discontinuity in marker labeling, for example, two consecutive frames labeled as 10:00:00:00 and 10:00:01:00 .

6.2.6 6.2.7 ttp:pixelAspectRatio

The ttp:pixelAspectRatio attribute may be used by a content author to express the aspect ratio of non-square pixels in the production of content that makes use of pixel coordinates.

If specified, the value of this attribute must adhere to the following syntax:

Syntax Representation – ttp:pixelAspectRatio
ttp:pixelAspectRatio ~~: width ":" height // != 0~~ : width height // width != 0; height != 0 width \| height : <digit>+

If not specified, then square pixels (i.e., aspect ratio 1:1) must be assumed to apply. If specified, then both width or and height must ~~not~~ be ~~zero.~~ non-zero .

A ttp:pixelAspectRatio attribute is considered to be significant only when specified on the tt element.

Note:

This parameter may be used by a content transcoder or translator in order to convert pixel measurements between different pixel aspect ratios while still maintaining authorial layout intentions.

6.2.7 6.2.8 ttp:profile

The ttp:profile attribute may be used by a content author to express the profile of the Timed Text Authoring Format (TT AF) used in a document instance.

If specified, the value of this attribute must adhere to the xsd:anyURI data type defined by [XML Schema Part 2] , §3.2.17, and, further, must specify a profile designator in accordance with 5.2 Profiles .

A ttp:profile attribute is considered to be significant only when specified on the tt element.

6.2.8 ttp:smpteMode The ttp:smpteMode attribute is used to specify constraints on the interpretation and use of frame counts that correspond with [SMPTE 12M] time coordinates when operating with time base of smpte as defined by 6.2.11 ttp:timeBase . If specified, the value of this attribute must adhere to the following syntax: Syntax Representation – ttp:smpteMode ttp:smpteMode : "dropNTSC" | "dropPAL" | "nonDrop" If the time base, defined by 6.2.11 ttp:timeBase , is designated as smpte , then this parameter applies as follows: if the parameter's value is nonDrop , then, within any given second of a time expression, frames count from 0 to N−1 , where N is the value specified by the ttp:frameRate parameter, but while ignoring any value specified by the ttp:frameRateMultiplier parameter. Note: When operating in nonDrop mode, a second of a time expression may or may not be equal to a second of real time during normal (1x speed) forward playback. If the ttp:frameRateMultiplier parameter is specified and is not equal to 1:1, then a second of a time expression will either be shorter or longer than a second of elapsed play in real time. If this parameter's value is dropNTSC , then, within any given second of a time expression except the second 00 , frames count from 0 to N−1 , where N is the value specified by the ttp:frameRate parameter, but while ignoring any value specified by the ttp:frameRateMultiplier parameter. If the second of a time expression is 00 and the minute of the time expression is not 00 , 10 , 20 , 30 , 40 , or 50 , then frame codes 00 and 01 are dropped during that second; otherwise, these frame codes are not dropped. Note: For example, when operating in dropNTSC mode with ttp:frameRate of 30 , a discontinuity in frame count occurs between consecutive frames as shown in the following sequence of time expressions: 01:08:59:28 , 01:08:59:29 , 01:09:00:02 , 01:09:00:03 . If this parameter's value is dropPAL , then, within any given second of a time expression except the second 00 , frames count from 0 to N−1 , where N is the value specified by the ttp:frameRate parameter, but while ignoring any value specified by the ttp:frameRateMultiplier parameter. If the second of a time expression is 00 and the minute of the time expression is even but not 00 , 20 , or 40 , then frame codes 00 through 03 are dropped during that second; otherwise, these frame codes are not dropped. Note: For example, when operating in dropPAL mode with ttp:frameRate of 30 , a discontinuity in frame count occurs between consecutive frames as shown in the following sequence of time expressions: 01:09:59:28 , 01:09:59:29 , 01:10:00:04 , 01:10:00:04 . Note: The dropPAL mode is also known as the M/PAL or PAL (M) drop-frame code, which uses PAL modulation with the NTSC frame rate of ~29.97 frames/second. The M/PAL system is used primarily in Brazil. If not specified, then nonDrop must be assumed to apply. A ttp:smpteMode attribute is considered to be significant only when specified on the tt element. 6.2.9 ttp:subFrameRate

The ttp:subFrameRate attribute is used to specify the sub-frame rate of a related media object or the intrinsic sub-frame rate of a document instance in case it is intended to function as an independent media object.

If specified, the value of this attribute must adhere to the following syntax:

Syntax Representation – ttp:subFrameRate
ttp:subFrameRate : <digit>+ // value > 0

The sub-frame rate that applies to a document instance is used to interpret time expressions that are expressed in sub-frames as defined by 10.3.1 <timeExpression> .

A sub-frame is interpreted as a division of a frame of media time, such that if the sub-frame rate is specified as S , then a frame of media time is divided into S intervals of equal duration, where each interval is labeled as sub-frame s , with s ∈ [0… S−1 ].

If not specified, the sub-frame rate must be considered to be equal to one (1). If specified, then the sub-frame rate must be greater than zero (0).

A ttp:subFrameRate attribute is considered to be significant only when specified on the tt element.

Note:

The sub-frame is sometimes referred to as a field in the context of synchronization with an interlaced video media object.

6.2.10 ttp:tickRate

The ttp:tickRate attribute is used to specify the tick rate of a related media object or the intrinsic tick rate of content of a document instance in case it is intended to function as an independent media object.

If specified, the value of this attribute must adhere to the following syntax:

Syntax Representation – ttp:tickRate
ttp:tickRate : <digit>+ // value > 0

The tick rate that applies to a document instance is used to interpret time expressions that are expressed in ticks by using the t metric as defined by 10.3.1 <timeExpression> .

A tick is interpreted as an integral division of a second of media time, such that if the tick rate is specified as T , then a second of media time is divided into T intervals of equal duration, where each interval is labeled as tick t , with t ∈ [0… T−1 ].

If not specified, then if a frame rate is specified, the tick rate must be considered to be the effective frame rate multiplied by the sub-frame rate (i.e., ticks are interpreted as sub-frames); or, if no frame rate is specified, the tick rate must be considered to be one (1) tick per second of media time. If specified, then the tick rate must not be zero (0).

Note:

There is no predefined relationship between ticks and frames or sub-frames. Ticks are an arbitrary division of seconds that permit use of fixed point arithmetic rather than fractional (and potentially inexact) expressions of seconds.

A ttp:tickRate attribute is considered to be significant only when specified on the tt element.

6.2.11 ttp:timeBase

The ttp:timeBase attribute is used to specify the temporal coordinate system by means of which time expressions are interpreted in a document instance.

If specified, the value of this attribute must adhere to the following syntax:

Syntax Representation – ttp:timeBase
ttp:timeBase : "media" \| "smpte" \| "clock"

If the time base is designated as media , then a time expression denotes a coordinate in some media object's time line, where the media object may be an external media object with which the content of a document instance is to be synchronized, or it may be the content of a document instance itself in a case where the timed text content is intended to establish an independent time line.

Note:

When using a media time base, if that time base is paused or scaled positively or negatively, then it is expected that the presentation of associated Timed Text content will be similarly paused, accelerated, or decelerated, respectively. The means for controlling an external media time base is outside the scope of this specification.

If the time base is designated as smpte , then a time expression denotes a [SMPTE 12M] time coordinate with which the content of a document instance is to be synchronized. In this case, the value of the ttp:markerMode and ttp:smpteMode ttp: dropMode parameters apply, as defined by ~~6.2.5~~ 6.2.6 ttp:markerMode and ~~6.2.8 ttp:smpteMode~~ 6.2.3 ttp:dropMode , respectively.

If the time base is designated as clock , then the time expression denotes a coordinate in some real-world time line as established by some real-time clock, such as the local wall-clock time or UTC (Coordinated Universal Time) or GPS (Global Positioning System) time lines.

If not specified, the default time base must be considered to be media .

A ttp:timeBase attribute is considered to be significant only when specified on the tt element.

When operating with either media or smpte time bases, a diachronic presentation of a document instance may be subject to transformations of the controlling time line, such as temporal reversal, dilation (expansion), or constriction (compression); however, when operating with the clock time base, no transformations are permitted, and diachronic presentation proceeds on a linear, monotonically increasing time line based on the passage of real time.

Note:

Due to there being only one time base parameter that applies to a given document instance, the interpretation of time expressions is uniform throughout the document instance.

When operating with the clock time base, the expression media time as used in this specification is to be interpreted as the real-time clock selected by 6.2.2 ttp:clockMode .

7 Content

This section specifies the content matter of the core vocabulary catalog.

7.1 Content Element Vocabulary

The following elements specify the structure and principal content aspects of a document instance:

7.1.1 tt
7.1.2 head
7.1.3 body
7.1.4 div
7.1.5 p
7.1.6 span
7.1.7 br

7.1.1 tt

The tt element serves as the ~~root,~~ root document element of a document instance.

The tt element accepts as its children zero or one head element followed by zero or one body element.

XML Representation – Element Information Item: tt
<tt tts:extent = string xml:id = ID xml:lang = string xml:space = (default\|preserve) : default {any attribute in TT Parameter namespace} {any attribute not in default or any TT namespace}> Content: head?, body? </tt>

XML Representation – Element Information Item: tt

<tt
  tts:extent = string
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve) : default
  {any attribute in TT Parameter namespace}
  {any attribute not in default or any TT namespace}>
  Content: head?, body?
</tt>

The temporal beginning and ending of a document instance represented by a tt element is defined in relationship with some external application or presentation context. The temporal interval defined by these points is referred to subsequently as the external time interval .

A document instance has an implicit duration that is equal to the implicit duration of the body element of the document, if present, or zero, if not present.

If the tts:extent attribute is specified on the tt element, then it must adhere to 8.2.8 tts:extent , in which case it specifies the spatial extent of the root container region in which content regions are located and presented. If no tts:extent attribute is specified, then the spatial extent of the root container region is considered to be determined by the external authoring or presentation context. The root container origin is determined by the external authoring context.

An xml:lang attribute must be specified on the tt element. If the attribute value is empty, it signifies that there is no default language that applies to the text contained within the document instance.

If no xml:space attribute is specified upon the tt element, then it must be considered as if the attribute had been specified with a value of default .

7.1.2 head

The head element is a container element used to group header matter, including metadata, profile, styling, and layout information.

The head element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more elements in the Parameters.class element group, followed by zero or one styling element, followed by zero or one layout element.

Any metadata specified by children in the Metadata.class element group applies semantically to the document instance as a whole, and not just the head element.

Any parameters specified by children in the Parameters.class element group applies semantically to the document instance as a whole, and not just the head element.

A styling child element is used to specify style constructs that are referenced from other style constructs, by layout constructs, and by content elements.

A layout child element is used to specify layout constructs that are referenced by content elements.

XML Representation – Element Information Item: head
<head xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute not in default or any TT namespace}> Content: Metadata.class, Parameters.class, styling?, layout? </head>

To the extent that time semantics apply to the content of the head element, the implied time interval of this element is defined to be coterminous with the external time interval.

7.1.3 body

The body element functions as a logical container and a temporal structuring element for a sequence of textual content units represented as logical divisions.

The body element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more elements in the Animation.class element group, followed by zero or more div elements.

Any metadata specified by children in the Metadata.class element group applies semantically to the body element and its descendants as a whole.

Any animation elements specified by children in the Animation.class element group apply semantically to the body element.

XML Representation – Element Information Item: body
<body begin = <timeExpression> dur = <timeExpression> end = <timeExpression> region = IDREF style = IDREFS timeContainer = (par\|seq) xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute in TT Metadata namespace} {any attribute in TT Style namespace} {any attribute not in default or any TT namespace}> Content: Metadata.class, Animation.class, div* </body>

XML Representation – Element Information Item: body

<body
  begin = <timeExpression>
  dur = <timeExpression>
  end = <timeExpression>
  region = IDREF
  style = IDREFS
  timeContainer = (par|seq)
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute in TT Metadata namespace}
  {any attribute in TT Style namespace}
  {any attribute not in default or any TT namespace}>
  Content: Metadata.class*, Animation.class*, div*
</body>

An author may specify a temporal interval for a body element using the begin , dur , and end attributes. If the begin point of this interval remains unspecified, then the begin point is interpreted as the begin point of the external time interval. Similarly, if the end point of this interval remains unspecified, then the end point is interpreted as the end point of the external time interval.

Note:

A TT AF document instance referenced from a SMIL presentation is expected to follow the same timing rules as apply to other SMIL media objects.

If relative begin or end times are specified on the body element, then these times are resolved by reference to the begin and end time of the external time interval.

If the external time interval is shorter than the computed duration of the body element, then the active time interval of a document instance is truncated to the active end point of the external time interval.

An author may associate a set of style properties with a body element by means of either the style attribute or inline style attributes or a combination thereof.

Note:

Style properties that are associated with a body element in a document instance are available for style inheritance by descendant content elements such as div , p , span and br .

If no timeContainer attribute is specified on a body element, then it must be interpreted as having parallel time containment semantics.

7.1.4 div

The div element functions as a logical container and a temporal structuring element for a sequence of textual content units represented as logical sub-divisions or paragraphs.

Note:

When rendered on a continuous (non-paged) visual presentation medium, a div element is expected to generate one or more block areas that contain zero or more child block areas generated by the div element's descendant p elements.

If some block area generated by a div element does not contain any child areas, then it is not expected to be presented.

The div element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more elements in the Animation.class element group, followed by zero or more div or p elements.

Any metadata specified by children in the Metadata.class element group applies semantically to the div element and its descendants as a whole.

Any animation elements specified by children in the Animation.class element group apply semantically to the div element.

XML Representation – Element Information Item: div
<div begin = <timeExpression> dur = <timeExpression> end = <timeExpression> region = IDREF style = IDREFS timeContainer = (par\|seq) xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute in TT Metadata namespace} {any attribute in TT Style namespace} {any attribute not in default or any TT namespace}> Content: Metadata.class, Animation.class, Block.class* </div>

XML Representation – Element Information Item: div

<div
  begin = <timeExpression>
  dur = <timeExpression>
  end = <timeExpression>
  region = IDREF
  style = IDREFS
  timeContainer = (par|seq)
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute in TT Metadata namespace}
  {any attribute in TT Style namespace}
  {any attribute not in default or any TT namespace}>
  Content: Metadata.class*, Animation.class*, Block.class*
</div>

An author may associate a set of style properties with a div element by means of either the style attribute or inline style attributes or a combination thereof.

Note:

Style properties that are associated with a div element in a document instance are available for style inheritance by descendant content elements such as div , p , span , and br .

If no timeContainer attribute is specified on a div element, then it must be interpreted as having parallel time containment semantics.

7.1.5 p

A p element represents a logical paragraph, serving as a transition between block level and inline level formatting semantics.

The p element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more elements in the Animation.class element group, followed by zero or more span element, br element, or text nodes interpreted as anonymous spans.

Any metadata specified by children in the Metadata.class element group applies semantically to the p element and its descendants as a whole.

Any animation elements specified by children in the Animation.class element group apply semantically to the p element.

XML Representation – Element Information Item: p
<p begin = <timeExpression> dur = <timeExpression> end = <timeExpression> region = IDREF style = IDREFS timeContainer = (par\|seq) xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute in TT Metadata namespace} {any attribute in TT Style namespace} {any attribute not in default or any TT namespace}> Content: Metadata.class, Animation.class, Inline.class* </p>

XML Representation – Element Information Item: p

<p
  begin = <timeExpression>
  dur = <timeExpression>
  end = <timeExpression>
  region = IDREF
  style = IDREFS
  timeContainer = (par|seq)
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute in TT Metadata namespace}
  {any attribute in TT Style namespace}
  {any attribute not in default or any TT namespace}>
  Content: Metadata.class*, Animation.class*, Inline.class*
</p>

An author may associate a set of style properties with a p element by means of either the style attribute or inline style attributes or a combination thereof.

Note:

Style properties that are associated with a p element in a document instance are available for style inheritance by descendant content elements such as span and br .

If no timeContainer attribute is specified on a p element, then it must be interpreted as having parallel time containment semantics.

If a sequence of children of a p element consists solely of character information items, then that sequence must be considered to be an anonymous span for the purpose of applying style properties that apply to span elements.

7.1.6 span

The span element functions as a logical container and a temporal structuring element for a sequence of textual content units having inline level formatting semantics.

When presented on a visual medium, a span element is intended to generate a sequence of inline areas, each containing one or more glyph areas.

The span element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more elements in the Animation.class element group, followed by zero or more span elements, br elements, or text nodes interpreted as anonymous spans.

Any metadata specified by children in the Metadata.class element group applies semantically to the span element and its descendants as a whole.

Any animation elements specified by children in the Animation.class element group apply semantically to the span element.

XML Representation – Element Information Item: span
<span begin = <timeExpression> dur = <timeExpression> end = <timeExpression> region = IDREF style = IDREFS timeContainer = (par\|seq) xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute in TT Metadata namespace} {any attribute in TT Style namespace} {any attribute not in default or any TT namespace}> Content: Metadata.class, Animation.class, Inline.class* </span>

XML Representation – Element Information Item: span

<span
  begin = <timeExpression>
  dur = <timeExpression>
  end = <timeExpression>
  region = IDREF
  style = IDREFS
  timeContainer = (par|seq)
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute in TT Metadata namespace}
  {any attribute in TT Style namespace}
  {any attribute not in default or any TT namespace}>
  Content: Metadata.class*, Animation.class*, Inline.class*
</span>

An author may associate a set of style properties with a span element by means of either the style attribute or inline style attributes or a combination thereof.

Note:

Style properties that are associated with a span element in a document instance are available for style inheritance by descendant content elements such as span and br .

If no timeContainer attribute is specified on a span element, then it must be interpreted as having parallel time containment semantics.

7.1.7 br

The br element denotes an explicit line break.

XML Representation – Element Information Item: br
<br style = IDREFS xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute in TT Metadata namespace} {any attribute in TT Style namespace} {any attribute not in default or any TT namespace}> Content: Metadata.class, Animation.class </br>

XML Representation – Element Information Item: br

<br
  style = IDREFS
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute in TT Metadata namespace}
  {any attribute in TT Style namespace}
  {any attribute not in default or any TT namespace}>
  Content: Metadata.class*, Animation.class*
</br>

When presented on a visual medium, the presence of a br element must be interpreted as a forced line break.

Note:

The visual presentation of a br element is intended to produce the same effect as the ASCII control code CR followed by the control code NL when presented on a teletype device. Therefore, two br elements in sequence will produce a different effect than a single br element.

7.2 Content Attribute Vocabulary

This section defines the following common attributes used with many or all element types in the core vocabulary catalog:

7.2.1 xml:id
7.2.2 xml:lang
7.2.3 xml:space

7.2.1 xml:id

The xml:id attribute is used as defined by [XML ID] .

The xml:id attribute may be used with any element in the core vocabulary catalog.

7.2.2 xml:lang

The xml:lang attribute is used as defined by [XML 1.0] , §2.12, Language Identification .

The xml:lang attribute must be specified on the tt element and may be specified by an instance of any other element type in the core vocabulary catalog.

7.2.3 xml:space

The xml:space attribute is used as defined by [XML 1.0] , §2.10, White Space Handling .

The xml:space attribute may be used with any element in the core vocabulary catalog.

The semantics of the value default are fixed to mean that when performing presentation processing of a document instance as described by 9.3.3 Synchronic Flow Processing , processing must occur as if the following properties were specified on the affected elements of the intermediate XSL-FO document:

suppress-at-line-break="auto"
linefeed-treatment="treat-as-space"
white-space-collapse="true"
white-space-treatment="ignore-if-surrounding-linefeed"

Similarly, the semantics of the value preserve are fixed to mean that when performing presentation processing, processing must occur as if the following properties were specified on the affected elements of the intermediate XSL-FO document:

suppress-at-line-break="retain"
linefeed-treatment="preserve"
white-space-collapse="false"
white-space-treatment="preserve"

When performing other types of processing intended to eventually result in a visual presentation by means other than those described in this specification, the semantics of space collapsing and preservation as described above should be respected. For other types of processing, the treatment of the xml:space attribute is processor dependent, but should respect the semantics described above if possible.

8 Styling

This section specifies the styling matter of the core vocabulary catalog, where styling is to be understood as a separable layer of information that applies to content and that denotes authorial intentions about the presentation of that content.

No normative use of an <?xml-stylesheet ... ?> processing instruction is defined by this specification.

8.1 Styling Element Vocabulary

The following elements specify the structure and principal styling aspects of a document instance:

8.1.1 styling
8.1.2 style

8.1.1 styling

The styling element is a container element used to group styling matter, including metadata that applies to styling matter.

The styling element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more style elements.

XML Representation – Element Information Item: styling
<styling xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute not in default or any TT namespace}> Content: Metadata.class, style </styling>

To the extent that time semantics apply to the content of the styling element, the implied time interval of this element is defined to be coterminous with the external time interval.

8.1.2 style

The style element is used to define a set of style specifications expressed as a specified style set in accordance with 8.4.4.2 Specified Style Set Processing .

The style element accepts as its children zero or more metadata elements.

XML Representation – Element Information Item: style

<style
  style = IDREFS
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute in TT Style namespace}
  {any attribute not in default or any TT namespace}>
  Content: Metadata.class*
</style>

If a style element appears as a descendant of a region element, then the style element must be ignored for the purpose of computing referential styles as defined by 8.4.1.2 Referential Styling and 8.4.1.3 Chained Referential Styling .

Note:

That is to say, when referential styling is used by an element to refer to a style element, then the referenced style element must appear as a descendant of the styling element, and not in any other context.

8.2 Styling Attribute Vocabulary

This section defines the 8.2.1 style attribute used with both style definition elements as well as content elements.

In addition, this section specifies the following attributes in the TT Style Namespace for use with style definition elements, certain layout elements, and content elements that support inline style specifications:

8.2.2 tts:backgroundColor
8.2.3 tts:color
8.2.4 tts:direction
8.2.5 tts:display
8.2.6 tts:displayAlign
8.2.7 tts:dynamicFlow
8.2.8 tts:extent
8.2.9 tts:fontFamily
8.2.10 tts:fontSize
8.2.11 tts:fontStyle
8.2.12 tts:fontWeight
8.2.13 tts:lineHeight
8.2.14 tts:opacity
8.2.15 tts:origin
8.2.16 tts:overflow
8.2.17 tts:padding
8.2.18 tts:showBackground
8.2.19 tts:textAlign
8.2.20 tts:textDecoration
8.2.21 tts:textOutline
8.2.22 tts:unicodeBidi
8.2.23 tts:visibility
8.2.24 tts:wrapOption
8.2.25 tts:writingMode
8.2.26 tts:zIndex

Unless explicitly stated otherwise, linear white-space (LWSP) may appear between tokens of a value of a TT Style or TT Style Extension Property.

Note:

This specification makes use of lowerCamelCased local names for style attributes that are based upon like-named properties defined by [XSL 1.1] . This convention is likewise extended to token values of such properties.

Note:

A style property may be expressed as a specified attribute on any content element type independently of whether the property applies to that element type. This capability permits the expression of an inheritable style property on ancestor elements to which the property property does not apply.

8.2.1 style

The style attribute is used by referential style association to reference one or more style elements each of which define a specified style set.

The style attribute may be specified by an instance of the following element types:

body
div
p
region
span
style

Note:

See the specific element type definitions that permit use of the style attribute, as well as 8.4.1.2 Referential Styling and 8.4.1.3 Chained Referential Styling , for further information on its semantics.

8.2.2 tts:backgroundColor

The tts:backgroundColor attribute is used to specify a style property that defines the background color of a region or an area generated by content flowed into a region.

This attribute may be specified by any element type that permits use of attributes in the TT Style Namespace; however, this attribute applies as a style property only to those element types indicated in the following table.

Values:	<color>
Initial:	`transparent`
Applies to:	`body` , `div` , `p` , `region` , `span`
Inherited:	no
Percentages:	N/A
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

The tts:backgroundColor style is illustrated by the following example.

Example Fragment – Background Color

<region xml:id="r1">
  <style tts:extent="306px 114px"/>
  <style tts:backgroundColor="red"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:padding="3px 40px"/>
</region>
...
<p region="r1" tts:backgroundColor="purple" tts:textAlign="center">
  Twinkle, twinkle, little bat!<br/>
  How <span tts:backgroundColor="green">I wonder</span> where you're at!
</p>

Example Rendition – Background Color

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.7.2.

8.2.3 tts:color

The tts:color attribute is used to specify a style property that defines the foreground color of marks associated with an area generated by content flowed into a region.

Values:	<color>
Initial:	see prose
Applies to:	`span`
Inherited:	yes
Percentages:	N/A
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

The initial value of the tts:color property is considered to be implementation dependent. In the absence of end-user preference information, a conformant presentation processor should use an initial value that is highly contrastive to the background color of the root container region.

The tts:color style is illustrated by the following example.

Example Fragment – Color

<region xml:id="r1">
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:textAlign="center"/>
</region>
...
<p region="r1">
  In spring, when woods are <span tts:color="green">getting green</span>,<br/>
  I'll try and tell you what I mean.
</p>

Example Rendition – Color

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.17.1.

8.2.4 tts:direction

The tts:direction attribute is used to specify a style property that defines the directionality of an embedding or override according to the Unicode bidirectional algorithm.

Values:	`ltr` \| `rtl`
Initial:	`ltr`
Applies to:	`p` , `span`
Inherited:	yes
Percentages:	N/A
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

If a specified value of this attribute is not supported, then a presentation processor must ignore the attribute.

The tts:direction style is illustrated by the following example.

Example Fragment – Direction

<region xml:id="r1">
  <style tts:extent="265px 84px"/>
  <style tts:padding="5px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:textAlign="center"/>
</region>
...
<p region="r1">
  Little birds are playing<br/>
  Bagpipes on the shore,<br/>
  <span tts:unicodeBidi="bidiOverride" tts:direction="rtl">where the tourists snore.</span>
</p>

Example Rendition – Direction

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.27.1.

8.2.5 tts:display

The tts:display attribute is used to specify a style property that defines whether an element is a candidate for layout and composition in a region.

Values:	`auto` \| `none`
Initial:	`auto`
Applies to:	`body` , `div` , `p` , `region` , `span`
Inherited:	no
Percentages:	N/A
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

If the value of this attribute is auto , then the affected element is a candidate for region layout and presentation; however, if the value is none , then the affected element and its descendants must be considered ineligible for region layout and presentation.

The tts:display style is illustrated by the following example.

Example Fragment – Display

<region xml:id="r1">
  <style tts:extent="369px 119px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="before"/>
  <style tts:textAlign="start"/>
</region>
...
<div region="r1">
  <p dur="5s">
    [[[
    <span tts:display="none">
      <set begin="1s" dur="1s" tts:display="auto"/>
      Beautiful soup,
    </span>
    <span tts:display="none">
      <set begin="2s" dur="1s" tts:display="auto"/>
      so rich and green,
    </span>
    <span tts:display="none">
      <set begin="3s" dur="1s" tts:display="auto"/>
      waiting in a hot tureen!
    </span>
    ]]]
  </p>
</div>

Example Rendition – Display

Note:

The semantics of the style property represented by this attribute are based upon that defined by [CSS2] , § 9.2.5.

8.2.6 tts:displayAlign

The tts:displayAlign attribute is used to specify a style property that defines the alignment of block areas in the block progression direction.

Values:	`before` \| `center` \| `after`
Initial:	`before`
Applies to:	`region`
Inherited:	~~yes~~ no
Percentages:	N/A
Animatable:	discrete

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value before were specified.

The tts:displayAlign style is illustrated by the following example.

Example Fragment – Display Align

<region xml:id="r1">
  <style tts:extent="128px 66px"/>
  <style tts:origin="0px 0px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="before"/>
  <style tts:textAlign="start"/>
</region>
<region xml:id="r2">
  <style tts:extent="192px 66px"/>
  <style tts:origin="128px 66px"/>
  <style tts:backgroundColor="green"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:textAlign="start"/>
</region>
<region xml:id="r3">
  <style tts:extent="128px 66px"/>
  <style tts:origin="0px 132px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="before"/>
  <style tts:textAlign="start"/>
</region>
<region xml:id="r4">
  <style tts:extent="192px 66px"/>
  <style tts:origin="128px 198px"/>
  <style tts:backgroundColor="green"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:textAlign="start"/>
</region>
...
<div>
  <p region="r1">I sent a message to the fish:</p>
  <p region="r2">I told them<br/> "This is what I wish."</p>
  <p region="r3">The little fishes of the sea,</p>
  <p region="r4">They sent an<br/> answer back to me.</p>
</div>

Example Rendition – Display Align

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.13.4.

8.2.7 tts:dynamicFlow

The tts:dynamicFlow attribute is used to specify a style property that defines how to dynamically flow content into and out of a region over some time interval.

This style property applies only to a region when the tts:overflow property for that region has the value dynamic .

Values:	`none` \| `rollUp` \| <flowFunction> + <flowIntervalFunction> *
Initial:	`none`
Applies to:	`region`
Inherited:	no
Percentages:	N/A
Animatable:	discrete

If the value of this attribute is none , then no dynamic flow semantics apply.

If the value of this attribute is rollUp , then this value is interpreted as a shorthand value equivalent to out(line,smooth) clear(0.433s) .

Note:

The choice of a definite duration of 0.433 seconds for the clear interval for roll up dynamic flow timing is based upon recommendations specified in [CC-DECODER-REQ] , p. 792.

If the value of this attribute contains a single <flowFunction> , then that flow function applies equally to fill into and clear from dynamic flow operations. Multiple instances of the same <flowFunction> must not appear in the value of this attribute.

If either fill() or clear() <flowIntervalFunction> is not specified, then the auto value for the missing <flowIntervalFunction> applies. Multiple instances of the same <flowIntervalFunction> must not appear in the value of this attribute.

The normative processing model for dynamic flow behavior is specified in B Dynamic Flow Processing Model .

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value none were specified.

The tts:dynamicFlow style is illustrated by the following example, and depicted in an SVG Animation .

Example Fragment – Dynamic Flow

<region xml:id="r1">
  <style tts:extent="140px 70px"/>
  <style tts:displayAlign="after"/>
  <style tts:backgroundColor="transparent"/>
  <style tts:fontFamily="proportionalSansSerif"/>
  <style tts:fontSize="18px"/>
  <style tts:overflow="dynamic"/>
  <style />

  <style tts:dynamicFlow="in(word,jump) fill(1.0s) out(line,smooth) clear(break,0.3s)"/>

</region>
...
<p region="r1">
  <span tts:backgroundColor="black" tts:color="white">
    Five o'clock tea!<br/>
    Ever to thee,<br/>
    Faithful I'll be,<br/>
    Five o'clock tea!<br/>
    <br/>
    <br/>
    <br/>
  </span>
</p>

Example Rendition – Dynamic Flow – Discrete Frames

8.2.8 tts:extent

The tts:extent attribute is used to specify the width and height of a region area (which may be the root container region).

Values:	`auto` \| <length> <length>
Initial:	`auto`
Applies to:	`tt` , `region`
Inherited:	no
Percentages:	relative to width and height of root container region
Animatable:	discrete

If the value of this attribute consists of two <length> specifications, then they must be interpreted as width and height , where the first specification is the width , and the second specification is the height .

If the value of this attribute is auto , then the initial value of the style property must be considered to be the same as the root container extent.

The root container extent is determined either by a tts:extent specified on the tt element, if present, or by the external authoring context, if not present. If tts:extent is specified on the tt element, then the width and height must be expressed in terms of two <length> specifications, and these specifications must be expressed as non-percentage, definite lengths using pixel units.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value auto were specified.

The tts:extent style is illustrated by the following example.

Example Fragment – Extent

<region xml:id="r1">
  <style tts:extent="330px 122px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:textAlign="center"/>
</region>
...
<p region="r1">
  'Tis the voice of the Lobster:<br/>
  I heard him declare,<br/>
  "You have baked me too brown,<br/>
  I must sugar my hair."
</p>

Example Rendition – Extent

8.2.9 tts:fontFamily

The tts:fontFamily attribute is used to specify a style property that defines the font family from which glyphs are selected for glyph areas generated by content flowed into a region.

Values:	( <familyName> \| <genericFamilyName> ) ( `","` ( <familyName> \| <genericFamilyName> ))*
Initial:	`default`
Applies to:	`span`
Inherited:	yes
Percentages:	N/A
Animatable:	discrete

Note:

The initial value, default , is a generic font family name, and is further described in 8.3.8 <genericFamilyName> below.

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

If a specified font family is not available, then a presentation processor must attempt to map the specified font family to an available font family that has similar typographic characteristics, or, in the absence of such a mapping, it must interpret the font family as if the value default were specified.

The tts:fontFamily style is illustrated by the following example.

Example Fragment – Font Family

<region xml:id="r1">
  <style tts:extent="474px 146px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="center"/>
  <style tts:textAlign="start"/>
  <style tts:fontFamily="proportionalSansSerif"/>
</region>
...
<div region="r1">
  <p>
    "The time has come," the Walrus said,<br/>
    "to talk of many things:
  </p>
  <p tts:textAlign="end" tts:fontFamily="monospaceSerif">
    Of shoes, and ships, and sealing wax,<br/>
    Of cabbages and kings,
  </p>
  <p>
    And why the sea is boiling hot,<br/>
    and whether pigs have wings."
  </p>
</div>

Example Rendition – Font Family

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.8.2.

8.2.10 tts:fontSize

The tts:fontSize attribute is used to specify a style property that defines the font size for glyphs that are selected for glyph areas generated by content flowed into a region, where font size is interpreted as a scaling transform to the font's design EM square.

Values:	<length> <length> ?
Initial:	`1c`
Applies to:	`span`
Inherited:	yes
Percentages:	relative to parent element's font size
Animatable:	discrete

If a single <length> value is specified, then this length applies equally to horizontal and vertical scaling of a glyph's EM square; if two <length> values are specified, then the first expresses the horizontal scaling and the second expresses vertical scaling.

Note:

Use of independent horizontal and vertical font sizes is expected to be used with cell based metrics in order to denote fonts that are two rows in height and one column in width.

If horizontal and vertical sizes are expressed independently, then the metrics of the <length> values must be the same.

The <length> value(s) used to express font size must be non-negative.

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value 1c were specified.

Note:

The expression 1c means one cell, where 'c' expresses the cell length unit as defined by 8.3.11 <length> .

The tts:fontSize style is illustrated by the following example.

Example Fragment – Font Size

<region xml:id="r1">
  <style tts:extent="299px 97px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="center"/>
  <style tts:textAlign="center"/>
  <style tts:fontFamily="proportionalSansSerif"/>
  <style tts:fontSize="18px"/>
</region>
...
<p region="r1">
  Then fill up the glasses<br/>
  with treacle and ink,<br/>
  Or anything else<br/>
  that is <span tts:fontSize="24px">pleasant</span> to drink.
</p>

Example Rendition – Font Size

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.8.4.

8.2.11 tts:fontStyle

The tts:fontStyle attribute is used to specify a style property that defines the font style to apply to glyphs that are selected for glyph areas generated by content flowed into a region, where the mapping from font style value to specific font face or style parameterization is not determined by this specification.

Values:	`normal` \| `italic` \| `oblique` \| `reverseOblique`
Initial:	`normal`
Applies to:	`span`
Inherited:	yes
Percentages:	N/A
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

Use of values oblique and reverseOblique denote a shear and reverse shear transformation (at an unspecified angle) in the inline progression dimension.

If a specified font style is not available, then a presentation processor must attempt to map the specified font style to an available font style that has similar typographic characteristics, or, in the absence of such a mapping, it must interpret the font style as if the value normal were specified.

The tts:fontStyle style is illustrated by the following example.

Example Fragment – Font Style

<region xml:id="r1">
  <style tts:extent="331px 84px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:textAlign="center"/>
  <style tts:fontFamily="proportionalSansSerif"/>
</region>
...
<p region="r1">
  In autumn, when the leaves are brown,<br/>
  Take pen and ink, and <span tts:fontStyle="italic">write it down.</span>
</p>

Example Rendition – Font Style

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.8.7.

8.2.12 tts:fontWeight

The tts:fontWeight attribute is used to specify a style property that defines the font weight to apply to glyphs that are selected for glyph areas generated by content flowed into a region, where the mapping from font weight value to specific font face or weight parameterization is not determined by this specification.

Values:	`normal` \| `bold`
Initial:	`normal`
Applies to:	`span`
Inherited:	yes
Percentages:	N/A
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

If a specified font weight is not available, then a presentation processor must attempt to map the specified font weight to an available font weight that has similar typographic characteristics, or, in the absence of such a mapping, it must interpret the font weight as if the value normal were specified.

The tts:fontWeight style is illustrated by the following example.

Example Fragment – Font Weight

<region xml:id="r1">
  <style tts:extent="376px 95px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="center"/>
  <style tts:textAlign="center"/>
  <style tts:fontFamily="proportionalSansSerif"/>
</region>
...
<p region="r1">
  They told me you had been to her,<br/>
  <span tts:fontWeight="bold">and mentioned me to him:</span><br/>
  She gave me a good character<br/>
  <span tts:fontWeight="bold">but said I could not swim.</span>
</p>

Example Rendition – Font Weight

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.8.9.

8.2.13 tts:lineHeight

The tts:lineHeight attribute is used to specify a style property that defines the inter-baseline separation between line areas generated by content flowed into a region.

Values:	`normal` \| <length>
Initial:	`normal`
Applies to:	`p`
Inherited:	yes
Percentages:	relative to this element's font size
Animatable:	discrete

If the value of this attribute is normal , then the initial value of the style property must be considered to be the same as the largest font size that applies to any descendant element.

If specified as a <length> , then the length must be non-negative.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value normal were specified.

The tts:lineHeight style is illustrated by the following example.

Example Fragment – Line Height

<region xml:id="r1">
  <style tts:extent="255px 190px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="center"/>
  <style tts:textAlign="start"/>
  <style tts:fontFamily="proportionalSansSerif"/>
  <style tts:fontSize="16px"/>
  <style tts:lineHeight="32px"/>
</region>
...
<p region="r1">
  He thought he saw an elephant,<br/>
  That practised on a fife:<br/>
  He looked again, and found it was<br/>
  A letter from his wife.<br/>
  "At length I realise," he said,<br/>
  "The bitterness of Life.
"</p>

Example Rendition – Line Height

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.15.4.

8.2.14 tts:opacity

The tts:opacity attribute is used to specify a style property that defines the opacity (or conversely, the transparency) of marks associated with a region.

When presented onto a visual medium, the opacity of the region is applied uniformly and on a linear scale to all marks produced by content targeted to the region.

Values:	<alpha>
Initial:	`1.0`
Applies to:	`region`
Inherited:	no
Percentages:	N/A
Animatable:	discrete

An <alpha> value greater than 1.0 must be considered equivalent to an <alpha> value of 1.0.

The tts:opacity style is illustrated by the following example.

Example Fragment – Opacity

<region xml:id="r1" dur="5s">
  <set begin="0s" dur="1s" tts:opacity="1.00"/>
  <set begin="1s" dur="1s" tts:opacity="0.75"/>
  <set begin="2s" dur="1s" tts:opacity="0.50"/>
  <set begin="3s" dur="1s" tts:opacity="0.25"/>
  <set begin="4s" dur="1s" tts:opacity="0.00"/>
  <style tts:extent="304px 77px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:textAlign="center"/>
</region>
...
<p region="r1">
  The sun was shining on the sea
</p>

Example Rendition – Opacity

Note:

The semantics of the style property represented by this attribute are based upon that defined by [CSS3 Color] , § 3.2.

8.2.15 tts:origin

The tts:origin attribute is used to specify the x and y coordinates of the origin of a region area with respect to the origin of the root container extent, if specified, or the external authoring context, if not specified.

Values:	`auto` \| <length> <length>
Initial:	`auto`
Applies to:	`region`
Inherited:	no
Percentages:	relative to width and height of root container region
Animatable:	discrete

If the value of this attribute consists of two <length> specifications, then they must be interpreted as x and y coordinates, where the first specification is the x coordinate, and the second specification is the y coordinate.

If the value of this attribute is auto , then the initial value of the style property must be considered to be the same as the root container origin. The root container origin is determined by the external authoring context.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value auto were specified.

The tts:origin style is illustrated by the following example.

Example Fragment – Origin

<region xml:id="r1">
  <style tts:origin="40px 40px"/>
  <style tts:extent="308px 92px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="center"/>
  <style tts:textAlign="center"/>
</region>
...
<p region="r1">
  "To dine!" she shrieked in dragon-wrath.<br/>
  "To swallow wines all foam and froth!<br/>
   To simper at a table-cloth!"
</p>

Example Rendition – Origin

8.2.16 tts:overflow

The tts:overflow attribute is used to specify a style property that defines whether a region area is clipped or not if the descendant areas of the region overflow its extent.

Values:	`visible` \| `hidden` \| `dynamic`
Initial:	`hidden`
Applies to:	`region`
Inherited:	no
Percentages:	N/A
Animatable:	discrete

If the value of this attribute is visible , then content should not be clipped outside of the affected region, and region composition and layout must be performed as if the region's width and height were unconstrained, but with a well-defined origin. If the value is hidden or dynamic , then content should be clipped outside of the affected region.

Note:

Unless a manual line break element br is used by the content author, a paragraph of a given region will generate no more than one line area in that region if the value of the tts:overflow style that applies to the region is visible and if the applicable tts:wrapOption style is noWrap .

If the value of this attribute is dynamic , then content is dynamically flowed into and out of the affected region according to the values of the tts:dynamicFlow style property; in this case, the semantics of the tts:dynamicFlow apply whether or not the affected region has overflowed.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value hidden were specified.

The tts:overflow style is illustrated by the following example.

Example Fragment – Overflow

<region xml:id="r1">
  <style tts:extent="232px 40px"/>
  <style tts:origin="0px 0px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="red"/>
  <style tts:displayAlign="before"/>
  <style tts:textAlign="start"/>
  <style tts:fontFamily="proportionalSansSerif"/>
  <style tts:fontSize="18px"/>
  <style tts:wrapOption="noWrap"/>
  <style tts:overflow="visible"/>
</region>
<region xml:id="r2">
  <style tts:extent="232px 40px"/>
  <style tts:origin="0px 43px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="red"/>
  <style tts:displayAlign="before"/>
  <style tts:textAlign="start"/>
  <style tts:fontFamily="proportionalSansSerif"/>
  <style tts:fontSize="18px"/>
  <style tts:wrapOption="noWrap"/>
  <style tts:overflow="hidden"/>
</region>
...
<p region="r1">
  "But wait a bit," the Oysters cried,<br/>
  "Before we have our chat;
</p>
<p region="r2">
  For some of us are out of breath,<br/>
  And all of us are fat!"
</p>

Example Rendition – Overflow

Note:

In the above example, the tts:noWrap is set to noWrap to prevent automatic line wrapping (breaking); if this were not specified, then overflow would occur in the block progression direction as opposed to the inline progression direction.

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.20.2.

8.2.17 tts:padding

The tts:padding attribute is used to specify padding (or inset) space on all sides of a region area.

Values:	<length> \| <length> <length> \| <length> <length> <length> \| <length> <length> <length> <length>
Initial:	`0px`
Applies to:	`region`
Inherited:	no
Percentages:	relative to width and height of region
Animatable:	discrete

If the value of this attribute consists of one <length> specification, then that length applies to all edges of the affected areas. If the value consists of two <length> specifications, then the first applies to the before and after edges, and the second applies to the start and end edges. If three <length> specifications are provided, then the first applies to the before edge, the second applies to the start and end edges, and the third applies to the after edge. If four <length> specifications are provided, then they apply to before, end, after, and start edges, respectively.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value 0px were specified.

The tts:padding style is illustrated by the following example.

Example Fragment – Padding

<region xml:id="r1">
  <style tts:extent="446px 104px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:textAlign="center"/>
  <style tts:padding="10px 40px"/>
</region>
...
<p region="r1" tts:backgroundColor="red">
  Just the place for a Snark! I have said it twice:<br/>
  That alone should encourage the crew.<br/>
  Just the place for a Snark! I have said it thrice:<br/>
  What I tell you three times is true.
</p>

When rendering an area to which padding applies, the background color that applies to the area is rendered into the padded portion of the area.

Example Rendition – Padding

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.29.15, except that individual shorthand values map to writing mode relative padding values as defined by [XSL 1.1] , § 7.7.31, 7.7.32, 7.7.33, and 7.7.34.

8.2.18 tts:showBackground

The tts:showBackground attribute is used to specify constraints on when the background color of a region is intended to be presented.

Values:	`always` \| `whenActive`
Initial:	`always`
Applies to:	`region`
Inherited:	no
Percentages:	N/A
Animatable:	discrete

If the value of this attribute is always , then the background color of a region is always rendered when performing presentation processing on a visual medium; if the value is whenActive , then the background color of a region is rendered only when some content is selected into the region.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value always were specified.

The tts:showBackground style is illustrated by the following example.

Example Fragment – Show Background

<region xml:id="r1">
  <style tts:origin="0px 0px"/>
  <style tts:extent="265px 100px"/>
  <style tts:backgroundColor="black"/>
  <style tts:showBackground="always"/>
  <style tts:color="white"/>
  <style tts:displayAlign="before"/>
  <style tts:textAlign="start"/>
</region>
<region xml:id="r2">
  <style tts:origin="205px 60px"/>
  <style tts:extent="290px 100px"/>
  <style tts:backgroundColor="red"/>
  <style tts:color="white"/>
  <style tts:displayAlign="before"/>
  <style tts:textAlign="end"/>
  <style tts:showBackground="whenActive"/>
</region>

Note:

The semantics of the style property represented by this attribute are based upon that defined by [SMIL 2.1] , § 5.3.1.

8.2.19 tts:textAlign

The tts:textAlign attribute is used to specify a style property that defines how inline areas are aligned within a containing block area in the inline progression direction.

Values:	`left` \| `center` \| `right` \| `start` \| `end`
Initial:	`start`
Applies to:	`p`
Inherited:	yes
Percentages:	N/A
Animatable:	discrete

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value start were specified.

The tts:textAlign style is illustrated by the following example.

Example Fragment – Text Align

<region xml:id="r1">
  <style tts:extent="355px 43px"/>
  <style tts:origin="0px 0px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:textAlign="start"/>
</region>
<region xml:id="r2">
  <style tts:extent="355px 43px"/>
  <style tts:origin="0px 47px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:textAlign="end"/>
</region>
...
<p region="r1">
  Beware the Jabberwock, my son!<br/>
  The jaws that bite, the claws that catch!
</p>
<p region="r2">
  Beware the Jubjub bird, and shun<br/>
  The frumious Bandersnatch!
</p>

Example Rendition – Text Align

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.15.9.

8.2.20 tts:textDecoration

The tts:textDecoration attribute is used to specify a style property that defines a text decoration effect to apply to glyph areas or other inline areas that are generated by content flowed into a region.

Values:	`none` \| [ [ `underline` \| `noUnderline` ] \|\| [ `lineThrough` \| `noLineThrough` ] \|\| [ `overline` \| `noOverline` ] ]
Initial:	`none`
Applies to:	`span`
Inherited:	yes
Percentages:	N/A
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value none were specified.

The tts:textDecoration style is illustrated by the following example.

Example Fragment – Text Decoration

<region xml:id="r1">
  <style tts:extent="385px 82px"/>
  <style tts:origin="0px 0px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:padding="5px 2px"/>
  <style tts:textDecoration="underline"/>
</region>
...
<p region="r1">
  The sea was wet<span tts:textDecoration="noUnderline"> as </span>wet
  <span tts:textDecoration="noUnderline">
    could be,<br/>
    The sand was dry as dry.<br/>
    <span tts:textDecoration="lineThrough">There weren't any</span>
    You <span tts:textDecoration="lineThrough">couldn't</span>
    could not see a cloud<br/>
    Because no cloud was in the sky.
  </span>
</p>

Example Rendition – Text Decoration

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.16.4.

8.2.21 tts:textOutline

The tts:textOutline attribute is used to specify a style property that defines a text outline effect to apply to glyphs that are selected for glyph areas generated by content flowed into a region.

Values:	`none` \| <color> ? <length> <length> ?
Initial:	`none`
Applies to:	`span`
Inherited:	yes
Percentages:	relative to this element's font size
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

The value of this attribute consists of an optional <color> term followed by one or two <length> terms. If a color term is present, then it denotes the outline color; if no color term is present, the computed value of the tts:color applies. The first length term denotes the outline thickness and the second length term, if present, indicates the blur radius.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value none were specified.

The tts:textOutline style is illustrated by the following example.

Example Fragment – Text Outline

<region xml:id="r1">
  <style tts:backgroundColor="transparent"/>
  <style tts:color="yellow"/>
  <style tts:textOutline="black 2px 0px"/>
  <style tts:fontFamily="proportionalSansSerif"/>
  <style tts:fontSize="24px"/>
</region>
...
<p>
  How doth the little crocodile<br/>
  Improve its shining tail,<br/>
  And pour the waters of the Nile<br/>
  On every golden scale!<br/>
  How cheerfully he seems to grin,<br/>
  How neatly spreads his claws,<br/>
  And welcomes little fishes in,<br/>
  With gently smiling jaws!
</p>

Example Rendition – Text Outline

8.2.22 tts:unicodeBidi

The tts:unicodeBidi attribute is used to specify a style property that defines a directional embedding or override according to the Unicode bidirectional algorithm.

Values:	`normal` \| `embed` \| `bidiOverride`
Initial:	`normal`
Applies to:	`p` , `span`
Inherited:	no
Percentages:	N/A
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value normal were specified.

The tts:unicodeBidi style is illustrated by the following example.

Example Fragment – Unicode Bidirectionality

<region xml:id="r1">
  <style tts:extent="265px 84px"/>
  <style tts:padding="5px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:textAlign="center"/>
</region>
...
<p region="r1">
  Little birds are playing<br/>
  Bagpipes on the shore,<br/>
  <span tts:unicodeBidi="bidiOverride" tts:direction="rtl">where the tourists snore.</span>
</p>

Example Rendition – Unicode Bidirectionality

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.27.6.

8.2.23 tts:visibility

The tts:visibility attribute is used to specify a style property that defines whether generated areas are visible or not when rendered on a visual presentation medium.

Values:	`visible` \| `hidden`
Initial:	`visible`
Applies to:	`body` , `div` , `p` , `region` , `span`
Inherited:	yes
Percentages:	N/A
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

The tts:visibility style has no affect on content layout or composition, but merely determines whether composed content is visible or not.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value visible were specified.

The tts:visibility style is illustrated by the following example.

Example Fragment – Visibility

<region xml:id="r1">
  <style tts:extent="398px 121px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style/>
</region>
...
<p region="r1" dur="4s">
  <span tts:visibility="hidden">
    <set begin="1s" tts:visibility="visible"/>
    Curiouser
  </span>
  <span tts:visibility="hidden">
    <set begin="2s" tts:visibility="visible"/>
    and
  </span>
  <span tts:visibility="hidden">
    <set begin="3s" tts:visibility="visible"/>
    curiouser!
  </span>
</p>

Example Rendition – Visibility

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.28.8.

8.2.24 tts:wrapOption

The tts:wrapOption attribute is used to specify a style property that defines whether or not automatic line wrapping (breaking) applies within the context of the affected element.

Values:	`wrap` \| `noWrap`
Initial:	`wrap`
Applies to:	`span`
Inherited:	yes
Percentages:	N/A
Animatable:	discrete

For the purpose of determining applicability of this style property, each character child of a p element is considered to be enclosed in an anonymous span.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value wrap were specified.

The tts:wrapOption style is illustrated by the following example.

Example Fragment – Wrap Option

<region xml:id="r1">
  <style tts:extent="192px 117px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:displayAlign="after"/>
  <style tts:overflow="hidden"/>
  <style tts:wrapOption="noWrap"/>
</region>
...
<p>
  I'll tell thee everything I can:<br/>
  There's little to relate.<br/>
  I saw an aged aged man,<br/>
  A-sitting on a gate.
</p>

Example Rendition – Wrap Option

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.15.13.

8.2.25 tts:writingMode

The tts:writingMode attribute is used to specify a style property that defines the block and inline progression directions to be used for the purpose of stacking block and inline areas within a region area.

Values:	`lrtb` \| `rltb` \| `tbrl` \| `tblr` \| `lr` \| `rl` \| `tb`
Initial:	`lrtb`
Applies to:	`region`
Inherited:	no
Percentages:	N/A
Animatable:	discrete

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value lrtb were specified.

The tts:writingMode style is illustrated by the following example.

Example Fragment – Writing Mode

<region xml:id="r1">
  <style tts:extent="50px 570px"/>
  <style tts:origin="0px 0px"/>
  <style tts:padding="10px 3px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:writingMode="tbrl"/>
</region>
<region xml:id="r2">
  <style tts:extent="310px 50px"/>
  <style tts:origin="70px 120px"/>
  <style tts:padding="10px 3px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:writingMode="rltb"/>
</region>
...
<p region="r1">
  I sometimes dig for buttered rolls,<br/>
  Or set limed twigs for crabs:
</p>
<p region="r2" tts:direction="rtl" tts:unicodeBidi="bidiOverride">
  I sometimes search the grassy knolls for the wheels of Hansom-cabs.
</p>

Example Rendition – Writing Mode

Note:

In the second paragraph in the above example that targets region r2 , the tts:unicodeBidi and tts:direction properties are set to bidiOverride and rtl , respectively, in order to override the normally left-to-right directionality of characters in the Latin script.

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.27.7.

8.2.26 tts:zIndex

The tts:zIndex attribute is used to specify a style property that defines the front-to-back ordering of region areas in the case that they overlap.

Values:	`auto` \| <integer>
Initial:	`auto`
Applies to:	`region`
Inherited:	no
Percentages:	N/A
Animatable:	discrete

If two areas are associated with the same Z-index value, then, if those areas overlap in space, the area(s) generated by lexically subsequent elements must be rendered over area(s) generated by lexically prior elements, where lexical order is defined as the postorder traversal of a document instance.

The semantics of the value auto are those defined by [XSL 1.1] , § 7.28.9, where the tt element is considered to establish the root stacking context.

If a specified value of this attribute is not supported, then a presentation processor must interpret the attribute as if the value auto were specified.

The tts:zIndex style is illustrated by the following example.

Example Fragment – Z Index

<region xml:id="r1">
  <style tts:origin="0px 0px"/>
  <style tts:extent="400px 100px"/>
  <style tts:padding="5px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:zIndex="0"/>
</region>
<region xml:id="r2">
  <style tts:origin="100px 60px"/>
  <style tts:extent="400px 100px"/>
  <style tts:padding="5px"/>
  <style tts:backgroundColor="red"/>
  <style tts:color="white"/>
  <style tts:textAlign="end"/>
  <style tts:zIndex="1"/>
</region>
<region xml:id="r3">
  <style tts:origin="0px 120px"/>
  <style tts:extent="400px 100px"/>
  <style tts:padding="5px"/>
  <style tts:backgroundColor="black"/>
  <style tts:color="white"/>
  <style tts:zIndex="2"/>
</region>
<region xml:id="r4">
  <style tts:origin="100px 180px"/>
  <style tts:extent="400px 100px"/>
  <style tts:padding="5px"/>
  <style tts:backgroundColor="red"/>
  <style tts:color="white"/>
  <style tts:textAlign="end"/>
  <style tts:zIndex="3"/>
</region>
...
<p region="r1">
  I passed by his garden, and marked, with one eye,<br/>
  How the Owl and the Panther were sharing a pie.
</p>
<p region="r2">
  The Panther took pie-crust, and gravy, and meat,<br/>
  While the Owl had the dish as its share of the treat.
</p>
<p region="r3">
  When the pie was all finished, the Owl, as a boon,<br/>
  Was kindly permitted to pocket the spoon:
</p>
<p region="r4">
  While the Panther received knife and fork<br/>
  with a growl,<br/>
  And concluded the banquet by...
</p>

Example Rendition – Z Index

Note:

The semantics of the style property represented by this attribute are based upon that defined by [XSL 1.1] , § 7.28.9.

8.3 Style Value Expressions

Style property values include the use of the following expressions:

8.3.1 <alpha>
8.3.2 <color>
8.3.3 <digit>
8.3.4 <duration>
8.3.5 <familyName>
8.3.6 <flowFunction>
8.3.7 <flowIntervalFunction>
8.3.8 <genericFamilyName>
8.3.9 <hexDigit>
8.3.10 <integer>
8.3.11 <length>
8.3.12 <namedColor>
8.3.13 <quotedString>
8.3.14 <string>

8.3.1 <alpha>

An <alpha> expression is used to express an opacity value, where 0 means fully transparent and 1 means fully opaque.

Syntax Representation – <alpha>
<alpha> : float

In the above syntax representation, the syntactic element float must adhere to the lexical representation defined by [XML Schema Part 2] § 3.2.4.1. If the value represented is less than 0.0, then it must be interpreted as equal to 0.0; similarly, if the value represented is greater than 1.0, then it must be interpreted as 1.0.

If a presentation processor does not support a specific, valid opacity value, then it must interpret it as being equal to the closest supported value.

8.3.2 <color>

A <color> expression is used to specify a named color, exact RGB color triple, or exact RGBA color tuple, where the alpha component, if expressed, is maximum (255) at 100% opacity and minimum (0) at 0% opacity, and where the applicable color space is defined by [SRGB] .

Syntax Representation – <color>

<color>
  : "#" rrggbb
  | "#" rrggbbaa
  | "rgb" "(" r-value "," g-value "," b-value ")"
  | "rgba" "(" r-value "," g-value "," b-value "," a-value ")"
  | <namedColor>
rrggbb
  :  <hexDigit>{6}
rrggbbaa
  :  <hexDigit>{8}
r-value | g-value | b-value | a-value
  : component-value
component-value
  : non-negative-integer                    // valid range: [0,255]
non-negative-integer
  : <digit>+

When expressing RGB component values, these values are considered to not be premultiplied by alpha.

For the purpose of performing presentation processing such that non-opaque or non-transparent alpha or opacity values apply, then the semantics of compositing functions are defined with respect to the use of the [SRGB] color space for both inputs and outputs of the composition function.

Note:

The use of [SRGB] for the stated semantics of composition is not meant to prevent an actual processor from using some other color space either for internal or external purposes. For example, a presentation processor may ultimately convert the SRGB values used here to the YUV color space for rendition on a television device.

If a presentation processor does not support a specific, valid color or alpha value, then it must interpret it as being equal to the closest supported value.

8.3.3 <digit>

A <digit> is used to express integers and other types of numbers or tokens.

Syntax Representation – <digit>
<digit> : "0" \| "1" \| "2" \| "3" \| "4" \| "5" \| "6" \| "7" \| "8" \| "9"

8.3.4 <duration>

A <duration> expression is used to express a temporal duration value.

Syntax Representation – <duration>
<duration> : <digit>+ ( "." <digit>+ )? metric metric : "s" // seconds \| "ms" // milliseconds \| "f" // frames \| "t" // ticks

It is an error to omit the metric component of a duration.

When operating with smpte time base and discontinuous mode, a duration expression must be considered to denote a duration in (local) real-time, independently of the governing time base.

8.3.5 <familyName>

A <familyName> expression specifies a font family name.

If the name contains a quotation delimiter character, then it must be expressed as a <quotedString>. If the name contains a whitespace character, then it should be expressed as a <quotedString>; however, if it is expressed as a <string>, then it must not contain a COMMA ',' character.

Syntax Representation – <familyName>
<familyName> : <string> \| <quotedString>

8.3.6 <flowFunction>

A <flowFunction> expression specifies a unit of content to be dynamic flowed into and out of a region according to an optional dynamic flow style.

Syntax Representation – <flowFunction>

<flowFunction>
  : "in(" flowArguments ")"
  | "out(" flowArguments ")"
flowArguments
  : flowUnit [ "," flowStyle ]
flowUnit
  : "glyph"
  | "line"
  | "character"
  | "word"
  | extensionToken
flowStyle
  : "jump"
  | "smooth"
  | extensionToken
extensionToken
  : "x-" <token>

Dynamic flow can be specified independently for flowing content into its region and flowing it out of its region. These two phases of dynamic flow are specified using the in() and out() flow functions respectively.

Dynamic flow occurs on the basis of specific visual or semantic content units. In the case of glyph and line , the unit of dynamic flow is based upon a visually rendered construct ( glyph ) or upon an area of the area tree produced by formatting the affected content. In the case of character and word , the unit of dynamic flow is based upon a semantic unit associated with one or more visually rendered or area units.

The dynamic flow unit word must be interpreted as being dependent upon the language or writing system of the affected content. If the language or writing system is unknown or unspecified, then word is interpreted as follows:

If the affected content consists solely or mostly of Unified CJK Ideographic characters or of characters of another Unicode character block that are afforded similar treatment to that of Unified CJK Ideographic characters, then word is to be interpreted as if character were specified.
Otherwise, word is to be interpreted as denoting a sequence of one or more characters that are not interpreted as an XML whitespace character.

When a flow unit is flowed into or out of its region, the manner by which the unit is flowed is controlled by the optional flowStyle argument of the relevant flow function. If the flow style is specified as jump , or if no flow style is specified, then the flow unit is instantaneously transitioned into, within, or out of the region. If the flow style is smooth , then the flow unit is smoothly transitioned by means of pixel based exposure, movement, or hiding, respectively.

If a presentation processor that supports dynamic flow does not support the smooth flow style, then this flow style must be interpreted as if the jump flow style were specified.

8.3.7 <flowIntervalFunction>

A <flowIntervalFunction> expression specifies an interval or duration that affects dynamic flow timing behavior.

Syntax Representation – <flowIntervalFunction>

<flowIntervalFunction>
  : "fill(" flowIntervalArguments ")"
  | "clear(" flowIntervalArguments ")"
flowIntervalArguments
  : "auto"

flowIntervalArguments
  : flowInterval [ "," flowStyleDuration ]
flowInterval
  : "auto"
  | "break"

  | <duration>
  | flowIntervalRate
flowIntervalRate
  : + )?

  : <digit>+ ( "." <digit>+ )?
flowStyleDuration
  : <duration>

The fill() flow interval function is used to determine the computed fill interval state parameter for performing dynamic flow processing, which expresses the duration of time between fill timer events, as specified by B.5.1 Fill Timer , which in turn, limits the dynamic flowed content fill rate.

The clear() flow interval function is used to determine the computed clear interval state parameter for performing dynamic flow processing, which expresses the duration of time between clear timer events, as specified by B.5.2 Clear Timer , which in turn, limits the dynamic flowed content retention period.

If the value auto is specified as the flow interval argument to a flow interval function, then an implied flow interval is computed dynamically.

If the value break is specified as the flow interval argument to a flow interval function, then the flow interval is variable, and depends upon the time at which a content unit is appended to the flow buffer or whose corresponding flow area is appended to the flow region, where the content unit is logically preceded by or followed by a manual line break element.

If a <duration> is specified as an the flow interval argument to a flow interval function, then it is considered to represent a definite duration . If a flow interval rate is specified as an argument to a flow interval ~~function,~~ function , then it is considered to represent a definite rate in units per second, where the applicable unit is determined in the context of whether the rate is used with an fill() or clear() flow interval function.

Note:

~~The~~ See B.3 Flow Interval Timing Calculation for further information on how the computed fill and clear interval values are ~~defined by~~ determined from <flowIntervalFunction> expressions.

If a <duration> is specified as the flow style duration argument to a flow interval function, then it is considered to represent the definite duration during which time the applicable flow style is to be applied in those cases where the applicable flow style has intrinsic duration semantics. If no flow style duration argument is specified and the applicable flow style has intrinsic duration semantics, then the duration must be considered to be equal to zero.

~~B.3 Flow Interval Timing Calculation~~ Note: .

In the current version of this specification, only the smooth flow style has intrinsic duration semantcs.

8.3.8 <genericFamilyName>

A <genericFamilyName> expression specifies a font family using a general token that indicates a class of font families.

The resolution of a generic family name to a concrete font instance is considered to be implementation dependent, both in the case of content authoring and content interpretation.

Syntax Representation – <genericFamilyName>
<genericFamilyName> : "default" \| "monospace" \| "sansSerif" \| "serif" \| "monospaceSansSerif" \| "monospaceSerif" \| "proportionalSansSerif" \| "proportionalSerif"

The mapping between a generic (font) family name and an actual font is not determined by this specification; however, the distinction of monospace versus proportional and serif versus sans-serif should be maintained if possible when performing presentation.

If a generic (font) family name of monospace is specified, then it may be interpreted as equivalent to either monospaceSansSerif or monospaceSerif . The generic family names sansSerif and serif are to be interpreted as equivalent to proportionalSansSerif and proportionalSerif , respectively.

If the generic family name default is specified (or implied by an initial value), then its typographic characteristics is considered to be implementation dependent; however, it is recommended that this default font family be mapped to an monospaced, sans-serif font.

8.3.9 <hexDigit>

A <hexDigit> is used to express integers and other types of numbers or tokens that employ base 16 arithmetic.

For the purpose of parsing, no distinction must be made between lower and upper case.

Syntax Representation – <hexDigit>
<hexDigit> : <digit> \| "a" \| "b" \| "c" \| "d" \| "e" \| "f" \| "A" \| "B" \| "C" \| "D" \| "E" \| "F"

8.3.10 <integer>

An <integer> expression is used to express an arbitrary, signed integral value.

Syntax Representation – <integer>
<integer> : ( "+" \| "-" )? <digit>+

8.3.11 <length>

A <length> expression is used to express either a coordinate component of point in a cartesian space or a distance between two points in a cartesian space.

Syntax Representation – <length>

<length>
  : scalar
  | percentage
scalar
  : number units
percentage
  : number "%"
sign
  : "+" | "-"
number
  : sign? non-negative-number
non-negative-number
  : non-negative-integer
  | non-negative-real
non-negative-integer
  : <digit>+
non-negative-real
  : <digit>* "." <digit>+
units
  : "px"
  | "em"
  | "c"                                     // abbreviation of "cell"

It is an error to omit the units component of a scalar length value.

The semantics of the unit of measure px (pixel) are as defined by [XSL 1.1] , § 5.9.13.

When specified relative to a font whose size is expressed as a single length measure or as two length measures of equal length, the unit of measure em is considered to be identical to that defined by [XSL 1.1] , § 5.9.13; however, when specified relative to a font whose size is expressed as two length measures of non-equal lengths, then one em is equal to the inline progression dimension of the ~~anisomorphically~~ anamorphically scaled font when used to specify lengths in the inline progression direction and equal to the block progression dimension of the scaled font when used to specify lengths in the block progression direction.

The semantics of the unit of measure c (cell) are defined by the parameter 6.2.1 ttp:cellResolution .

8.3.12 <namedColor>

A <namedColor> is used to express an RGBA color with a convenient name, and where the applicable color space is defined by [SRGB] .

For the purpose of parsing, no distinction must be made between lower and upper case.

Syntax Representation – <namedColor>

<namedColor>
  : "transparent"                           // #00000000
  | "black"                                 // #000000ff
  | "silver"                                // #c0c0c0ff
  | "gray"                                  // #808080ff
  | "white"                                 // #ffffffff
  | "maroon"                                // #800000ff
  | "red"                                   // #ff0000ff
  | "purple"                                // #800080ff
  | "fuchsia"                               // #ff00ffff
  | "magenta"                               // #ff00ffff (= fuchsia)
  | "green"                                 // #008000ff
  | "lime"                                  // #00ff00ff
  | "olive"                                 // #808000ff
  | "yellow"                                // #ffff00ff
  | "navy"                                  // #000080ff
  | "blue"                                  // #0000ffff
  | "teal"                                  // #008080ff
  | "aqua"                                  // #00ffffff
  | "cyan"                                  // #00ffffff (= aqua)

Note:

Except for transparent , the set of named colors specified above constitutes a proper subset of the set of named colors specified by [SVG 1.1] , § 4.2.

8.3.13 <quotedString>

A <quotedString> is used to express a delimited string that may contain a whitespace or a quotation delimiter character. Two types of quotation delimiters are provided in order to accommodate strings that contain the other delimiter.

Syntax Representation – <quotedString>
<quotedString> : "\"" ( char - { "\"" } )* "\"" \| "\'" ( char - { "\'" } )* "\'"

In the above syntax representation, the syntactic element char must adhere to production [2] Char as defined by [XML 1.0] § 2.2.

8.3.14 <string>

A <string> expression consists of a sequence of characters where no character is a quotation delimiter character.

Syntax Representation – <string>
<string> : ( char - { "\"" \| "\'" } )+

In the above syntax representation, the syntactic element char must adhere to production [2] Char as defined by [XML 1.0] § 2.2.

8.4 Style Resolution

This section defines the semantics of style resolution in terms of a standard processing model as follows:

8.4.1 Style Association
8.4.2 Style Inheritance
8.4.3 Style Resolution Value Categories
8.4.4 Style Resolution Processing

Any implementation of this model is permitted provided that the externally observable results are consistent with the results produced by this model.

Note:

The semantics of style resolution employed here are based upon [XSL 1.1] , § 5.

8.4.1 Style Association

Style association is a sub-process of 8.4.4 Style Resolution Processing used to determine the specified style set of each content and layout element.

Style matter may be associated with content and layout matter in a number of ways:

inline styling
referential styling
chained referential styling

In addition to the above, style matter may be associated with layout matter using:

nested styling

8.4.1.1 Inline Styling

Style properties may be expressed in an inline manner by direct specification of an attribute from the TT Style Namespace on the affected element. When expressed in this manner, the association of style information is referred to as inline styling .

Style properties associated by inline styling are afforded a higher priority than all other forms of style association.

Example – Inline Styling
<p tts:color="white">White 1 <span tts:color="yellow">Yellow</span> White 2</p>

Note:

In the above example, the two text fragments "White 1 " and " White 2" , which are interpreted as anonymous spans, are not associated with a color style property; rather, they inherit their color style from their parent p element as described in 8.4.2.1 Content Style Inheritance below.

8.4.1.2 Referential Styling

Style properties may be expressed in an out-of-line manner and referenced by the affected element using the style attribute. When expressed in this manner, the association of style information is referred to as referential styling .

If a style attribute specifies multiple references, then those references are evaluated in the specified order, and that order applies to resolution of the value of a style property in the case that it is specified along multiple reference paths.

The use of referential styling is restricted to making reference to style element descendants of a styling element. It is considered an error to reference a style element that is a descendant of a layout element.

Note:

The use of referential styling encourages the reuse of style specifications while sacrificing locality of reference.

Note:

A single content element may be associated with style properties by a hybrid mixture of inline and referential styling, in which case inline styling is given priority as described above by 8.4.1.1 Inline Styling .

Example – Referential Styling
<style xml:id="s1" tts:color="white"/> <style xml:id="s2" tts:color="yellow"/> ... <p style="s1">White 1 <span style="s2">Yellow</span> White 2</p>

Note:

8.4.1.3 Chained Referential Styling

Style properties may be expressed in an out-of-line manner and may themselves reference other out-of-line style properties, thus creating a chain of references starting at the affected element. When expressed in this manner, the association of style information is referred to as chained referential styling .

If the same style property is specified in more than one referenced style set, then the last referenced style set applies, where the order of application starts from the affected element and proceeds to referenced style sets, and, in turn, to subsequent, recursively referenced style sets.

A loop in a sequence of chained style references must be considered an error.

Note:

The use of chained referential styling encourages the grouping of style specifications into general and specific sets, which further aids in style specification reuse.

Note:

A single content element may be associated with style properties by a hybrid mixture of inline, referential styling, and chained referential styling, in which case inline styling is given priority as described above by 8.4.1.1 Inline Styling .

Example – Chained Referential Styling
<style xml:id="s1" tts:color="white" tts:fontFamily="monospaceSerif"/> <style xml:id="s2" style="s1" tts:color="yellow"/> ... <p style="s1">White Monospace</p> <p style="s2">Yellow Monospace</p>

8.4.1.4 Nested Styling

Style properties may be expressed in an nested manner by direct specification of one or more style element children of the affected element. When expressed in this manner, the association of style information is referred to as nested styling .

Style properties associated by nested styling are afforded a lower priority than inline styling but with higher priority than referential styling.

Example – Nested Styling
<region xml:id="r1"> <style tts:extent="128px 66px"/> <style tts:origin="0px 0px"/> <style tts:displayAlign="center"/> </region>

Note:

In this version of this specification, nested styling applies only to the region element.

8.4.2 Style Inheritance

Style inheritance is a sub-process of 8.4.4 Style Resolution Processing used to determine the specified style set of each content and layout element.

Styles are further propagated to content matter using:

content style inheritance
region style inheritance

For the purpose of determining inherited styles, the element hierarchy of an intermediate synchronic document form of a DFXP document instance must be used, where such intermediate forms are defined by 9.3.2 Intermediate Synchronic Document Construction .

Note:

The intermediate synchronic document form is utilized rather than the original form in order to facilitate region inheritance processing.

8.4.2.1 Content Style Inheritance

Style properties are inherited from ancestor content elements within an intermediate synchronic document if a style property is not associated with a content element (or an anonymous span) and the style property is designated as inheritable.

If a style property is determined to require inheritance, then the inherited value must be the value of the same named style property in the computed style set of the element's immediate ancestor element within the applicable intermediate synchronic document.

Example – Content Style Inheritance
<p tts:fontFamily="monospaceSansSerif"> <span tts:color="yellow">Yellow Monospace</span> </p>

Note:

In the above example, the span element that encloses the character items Yellow Monospace is not associated with a tts:fontFamily style property and this property is inheritable; therefore, the value of the tts:fontFamily style is inherited from the computed style set of the ancestor p element, and is added to the specified style set of the span element.

8.4.2.2 Region Style Inheritance

Style properties are inherited from a region element in the following case:

if a style property P is not associated with a content element or an anonymous span E and the style property is designated as inheritable, and
if that style property P is in the computed style set of region R , and
if that element E is flowed into (presented within) region R .

Example – Region Style Inheritance
<region xml:id="r1"> <style tts:color="yellow"/> <style tts:fontFamily="monospaceSerif"/> </region> ... <p region="r1">Yellow Monospace</p>

Note:

In the above example, the anonymous span that encloses the character items Yellow Monospace effectively inherits the tts:color and tts:fontFamily styles specified on the region element into which the p element is flowed (presented).

8.4.3 Style Resolution Value Categories

During style resolution, layout, and presentation processing, three categories of style property values are distinguished as follows:

specified values
computed values
actual values

8.4.3.1 Specified Values

Values of style properties that are associated with or inherited by an element or anonymous span are referred to as specified values . The set of all specified style properties of a given element is referred to as the specified style set of that element.

8.4.3.2 Computed Values

When style properties are specified using relative value expressions, such as a named color, a relative unit (e.g., cell), or a percentage, then they need to be further resolved into absolute units, such as an RGB triple, pixels, etc.

During the style resolution process, all specified style values are reinterpreted (or recalculated) in absolute terms, and then recorded as computed values . The set of all computed style properties of a given element is referred to as the computed style set of that element.

When a style value is inherited, either explicitly or implicitly, it is the computed value of the style that is inherited from an ancestor element. This is required since the resolution of certain relative units, such as percentage, require evaluating the expression in the immediate (local) context of reference, and not in a distant (remote) context of reference where the related (resolving) expression is not available.

8.4.3.3 Actual Values

During the actual presentation process, other transformations occur that map some value expressions to concrete, physical values. For example, the colors of computed style values are further subjected to closest color approximation and gamma correction during the display process. In addition, length value expressions that use pixels in computed style values are considered to express logical rather than physical (device) pixels. Consequently, these logical pixels are subject to being further transformed or mapped to physical (device) pixels during presentation.

The final values that result from the logical to device mapping process are referred to as actual values . The set of all actual style properties of a given element is referred to as the actual style set of that element.

Note:

More than one set of actual values may be produced during the process of presentation. For example, a DFXP presentation processor device may output an RGBA component video signal which is then further transformed by an NTSC or PAL television to produce a final image. In this case, both color and dimensions may further be modified prior to presentation.

Note:

In general, a DFXP presentation processor will not have access to actual style set values; as a consequence, no further use or reference to actual values is made below when formally describing the style resolution process.

8.4.4 Style Resolution Processing

The process of style resolution is defined herein as the procedure (and results thereof) for resolving (determining) the computed values of all style properties that apply to content and layout elements:

8.4.4.1 Conceptual Definitions
8.4.4.2 Specified Style Set Processing
8.4.4.3 Computed Style Set Processing
8.4.4.4 Style Resolution Process

The process described here forms an integral sub-process of 9.3 Region Layout and Presentation .

8.4.4.1 Conceptual Definitions

For the purpose of interpreting the style resolution processing model specified below, the following conceptual definitions apply:

[style property]

a style property, P , is considered to consist of a tuple [name, value] , where the name of the property is a tuple [namespace value, unqualified name] and the value of the property is a tuple [category, type, value expression]

Example – conceptual style property
[ ["http://www.w3.org/2006/10/ttaf1#styling", "color"], ["specified", color, "red"] ]

[style (property) set]

a style (property) set consists of an unordered collection of style properties, where no two style properties within the set have an identical name, where by "identical name" is meant equality of namespace value of name tuple and unqualified name of name tuple;

in a specified style (property) set, the category of each style property is "specified"; a specified style (property) set of an element E is referred to as SSS(E) ;

Example – conceptual (specified) style (property) set

{
  [
    ["http://www.w3.org/2006/10/ttaf1#styling", "backgroundColor"],
    ["specified", color, 0x00FF00 ]
  ],
  [
    ["http://www.w3.org/2006/10/ttaf1#styling", "color"],
    ["specified", color, "red" ]
  ],
  [
    ["http://www.w3.org/2006/10/ttaf1#styling", "fontSize"],
    ["specified", length, "1c" ]
  ],
  [
    ["http://www.w3.org/2006/10/ttaf1#styling", "lineHeight"],
    ["specified", length, "117%" ]
  ]
}

in a computed style (property) set, the category of each style property is either "specified" or "computed"; a computed style (property) set of an element E is referred to as CSS(E) ;

Example – conceptual (computed) style (property) set

{
  [
    ["http://www.w3.org/2006/10/ttaf1#styling", "backgroundColor"],
    ["specified", color, 0x00FF00 ]
  ],
  [
    ["http://www.w3.org/2006/10/ttaf1#styling", "color"],
    ["computed", color, 0xFF0000 ]
  ],
  [
    ["http://www.w3.org/2006/10/ttaf1#styling", "fontSize"],
    ["computed", length, "24px" ]
  ],
  [
    ["http://www.w3.org/2006/10/ttaf1#styling", "lineHeight"],
    ["computed", length, "28px" ]
  ]
}

[style (property) merging]

a style property P _new is merged into a style (property) set, SS , as follows: if a style property P _old is already present in SS where the name of P _new is identical to the name of P _old , then replace P _old in SS with P _new ; otherwise, add P _new to SS ;

[style (property) set merging]

a style (property) set SS _new is merged into an existing style (property) set SS _old as follows: for each style property P _new in SS _new , merge P _new into SS _old ;

8.4.4.2 Specified Style Set Processing

The specified style set SSS of an element or anonymous span E , SSS(E) , is determined according to the following ordered rules:

[initialization] initialize the specified style set SSS of E to the empty set;
[referential and chained referential styling] for each style element S _REF referenced by a style attribute specified on E , and in the order specified in the style attribute, then, if S _REF is a descendant of a styling element, merge the specified style set of S _REF , SSS(S _REF ) , into the specified style set of E , SSS(E) ;
[nested styling] for each nested style element child S _NEST of E , and in the specified order of child elements, merge the specified style set of S _NEST , SSS(S _NEST ) , into the specified style set of E , SSS(E) ;
[inline styling] for each style property P expressed as a specified styling attribute of E , merge P into the specified style set of E , SSS(E) ;
[implicit inheritance] if the element type of E is not the styling element type style , then for each inheritable style property P _INH in the set of style properties defined above in 8.2 Styling Attribute Vocabulary , perform the following ordered sub-steps:
1. if P _INH is present in the specified style set of E , SSS(E) , then continue to the next inheritable style property;
2. if the element type of E is the layout element type region , then set P′ to the initial value of property P , where the initial value of a property is determined according to the specific property definition found above in 8.2 Styling Attribute Vocabulary ;
3. if the element type of E is a content element type or anonymous span, then set P′ to the result of looking up the value of P in the computed style set of the immediate ancestor element of E , i.e., CSS(PARENT(E)) ;
4. if the value of P′ is not undefined, then merge P′ into the specified style set of E , SSS(E) .

8.4.4.3 Computed Style Set Processing

The computed style set CSS of an element or anonymous span E , CSS(E) , is determined according to the following ordered rules:

[resolve specified styles] determine (obtain) the specified style set SSS of E , namely, SSS(E) , in accordance with 8.4.4.2 Specified Style Set Processing ;
[initialization] initialize CSS(E) to a (deep) copy of SSS(E) ;
[filter] if E is a style element, then return CSS(E) as the resulting computed style set without further resolution; otherwise, continue with the next rule;
[relative value resolution] for each style property P in CSS(E) , where the value type of P is relative, perform the following ordered sub-steps:
1. replace the relative value of P with an equivalent, non-relative (computed) value;
2. set the category of P to "computed";

Note:

As a result of the filtering rule above, the computed style set of a style element includes only specified values, in which case relative value expressions remain relative; consequently, the resolution of relative value expressions (that may be assigned by means of referential style association) always takes place in the context of a layout or content element which has a presentation context, and not in the non-presentation, declaration context of a referentiable style element.

8.4.4.4 Style Resolution Process

The top-level style resolution process is defined as follows: using a preorder traversal of each element and anonymous span, E , of an intermediate synchronic document, DOC _inter , perform the following ordered sub-steps:

[filter] if the element type of E is not the styling element type style , is not the layout element type region , and is not one of the content element types body , div , p , span , br , or anonymous span, then continue to the next element in the preorder traversal;
[resolve computed styles] determine (obtain) the computed style set CSS of E , namely, CSS(E) , in accordance with 8.4.4.3 Computed Style Set Processing .

9 Layout

This section specifies the layout matter of the core vocabulary catalog, where layout is to be understood as a separable layer of information that applies to content and that denotes authorial intentions about the presentation of that content.

Note:

The two layers of layout and style matter are considered to be independently separable. Layout matter specifies one or more spaces or areas into which content is intended to be presented, while style matter specifies the manner in which presentation occurs within the layout.

In certain cases, a content author may choose to embed (inline) style matter directly into layout or content matter. In such cases, an alternative exists – use of referential styling – in which the style matter is not embedded (inlined).

9.1 Layout Element Vocabulary

The following elements specify the structure and principal layout aspects of a document instance:

9.1.1 layout
9.1.2 region

9.1.1 layout

The layout element is a container element used to group layout matter, including metadata that applies to layout matter.

The layout element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more region elements.

XML Representation – Element Information Item: layout
<layout xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute not in default or any TT namespace}> Content: Metadata.class, region </layout>

To the extent that time semantics apply to the content of the layout element, the implied time interval of this element is defined to be coterminous with the external time interval.

9.1.2 region

The region element is used to define a space or area into which content is to be flowed for the purpose of presentation.

In addition, and in accordance with 8.4.2.2 Region Style Inheritance , the region element may be used to specify inheritable style properties to be inherited by content that is flowed into it.

The region element accepts as its children zero or more elements in the Metadata.class element group, followed by zero or more elements in the Animation.class element group, followed by zero or more style elements.

Any metadata specified by children in the Metadata.class element group applies semantically to the region element and its descendants as a whole. Any animation elements specified by children in the Animation.class element group apply semantically to the region element. Any style child element must be considered a local style definition that applies only to the containing region element, i.e., does not apply for resolving referential styling.

XML Representation – Element Information Item: region

<region
  begin = <timeExpression>
  dur = <timeExpression>
  end = <timeExpression>
  style = IDREFS
  timeContainer = (par|seq)
  ttm:role = string
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute in TT Style namespace}
  {any attribute not in default or any TT namespace}>
  Content: Metadata.class*, Animation.class*, style*
</region>

If begin and (or) end attributes are specified on a region element, then they specify the beginning and (or) ending points of a time interval during which the region is eligible for activation and with respect to which animation child elements of the region are timed. If specified, these begin and end points are relative to the time interval of the nearest ancestor element associated with a time interval, irregardless of whether that interval is explicit or implied.

The nearest ancestor element of a region element that is associated with a time interval is the document instance's root tt element.

If a dur attribute is specified on the region element, then it specifies the simple duration of the region.

For the purpose of determining the semantics of presentation processing, a region that is temporally inactive must not produce any visible marks when presented on a visual medium.

Note:

A region element may be associated with a time interval for two purposes: (1) in order to temporally bound the presentation of the region and its content, and (2) to provide a temporal context in which animations of region styles may be effected.

For example, an author may wish a region that is otherwise empty, but may have a visible background color to be presented starting at some time and continuing over the region's duration. The simple duration of the region serves ~~additionaly~~ additional l y to scope the presentation effects of content that is targeted to the region. An author may also wish to move a region within the root container extent or change a region's background color by means of animation effects. In both of these cases, it is necessary to posit an active time interval for a region.

If no timeContainer attribute is specified on a region element, then it must be interpreted as having parallel time containment semantics.

If a ttm:role attribute is specified on a region element, then it must adhere to the value syntax defined by Syntax Representation – ttm:role , and where the role(s) identified by this attribute expresses the semantic role(s) of the region independently from the semantic role(s) of any content targeted to (associated with) the region.

9.2 Layout Attribute Vocabulary

This section defines the 9.2.1 region attribute used with content elements.

9.2.1 region

The region attribute is used to reference a region element which defines a space or area into which a content element is intended to be flowed.

The region attribute may be specified by an instance of the following element types:

body
div
p
span

Note:

See 9.3 Region Layout and Presentation below for further information on content flow in a region.

9.3 Region Layout and Presentation

This section defines the semantics of region layout and presentation in terms of a standard processing model as follows:

9.3.1 Default Region
9.3.2 Intermediate Synchronic Document Construction
9.3.3 Synchronic Flow Processing
9.3.4 Elaborated Example

Any implementation is permitted provided that the externally observable results are consistent with the results produced by this model.

9.3.1 Default Region

If a DFXP document instance does not specify a region element, then a default region is implied with the following characteristics:

the identity of the default region is considered to be anonymous;
the extent of the default region is the same as the root container region;
the temporal interval of the default region is the same as temporal interval of the document instance;

Furthermore, if no region element was specified, then the region attribute must not be specified on any content element in the document instance.

If a default region is implied for a given document instance, then the body element is implicitly targeted to (associated with) the default region.

When implying a default region, the document instance is to be treated as if a region element and its parent layout element were specified in a head element, and a matching region attribute were specified on the body element as shown in the following example:

Example – Implied Default Region
<tt xml:lang="" xmlns="http://www.w3.org/2006/10/ttaf1"> <head> <layout> <region xml:id="anonymous"/> </layout> </head> <body region="anonymous"/> </tt>

Note:

In the above example, a default region element and region attribute are implied. In addition, a layout container element is implied for the implied region element.

9.3.2 Intermediate Synchronic Document Construction

For the purposes of performing presentation processing, the active time duration of a document instance is divided into a sequence of time coordinates where at each time coordinate, some element becomes temporally active or inactive, then, at each such time coordinate, a document instance is mapped from its original, source form, DOC _source , to an intermediate synchronic document form, DOC _inter , as follows:

for each temporally active region R , replicate the sub-tree of DOC _source headed by the body element;
evaluating this sub-tree in a postorder traversal, prune elements if they are not a content element, if they are temporally inactive, if they are empty, or if they aren't associated with region R ;
if the pruned sub-tree is non-empty, then reparent it to the R element;
finally, after completing the above steps, prune the original body element from the intermediate document, then prune all region , begin , end , and dur attributes, which are no longer semantically relevant;

A content element is associated with a region according to the following ordered rules, where the first rule satisfied is used and remaining rules are skipped:

if the element specifies a region attribute, then the element is associated with the region referenced by that attribute;
if some ancestor of that element specifies a region attribute, then the element is associated with the region referenced by the most immediate ancestor that specifies this attribute;
if the element contains a descendant element that specifies a region attribute, then the element is associated with the region referenced by that attribute;
if a default region was implied (due to the absence of any region element), then the element is associated with the default region;
the element is not associated with any region.

The pseudo-code shown in Example – Content Hierarchy Region Mapping provides one possible algorithm that implements these processing steps.

Example – Content Hierarchy Region Mapping

PREPARE-CONTENT ( D ) := 
  foreach R in SELECT ( D, "/tt/head/layout/region" )
    if TEMPORALLY-ACTIVE? ( R )
      APPEND-CHILDREN ( R, SELECT ( D, "/tt/body" ) )
      foreach E in POSTORDER-TRAVERSE ( R )
        if ! CONTENT-ELEMENT? ( E ) or ! TEMPORALLY-ACTIVE? ( E ) or EMPTY? ( E ) or REGION-OF ( E ) != R
            then PRUNE ( E )
  PRUNE ( SELECT ( D, "/tt/body" ) )
  PRUNE ( SELECT ( D, "//*/@region" ) )
  PRUNE ( SELECT ( D, "//*/@begin" ) )
  PRUNE ( SELECT ( D, "//*/@end" ) )
  PRUNE ( SELECT ( D, "//*/@dur" ) )
 
REGION-OF ( E ) :=
  if NULL? ( E )
    return NULL
  else if HAS-ATTRIBUTE? ( E, "region" )
    return VALUE-OF-ATTRIBUTE ( E, "region" )
  else
    return REGION-OF ( PARENT-OF ( E ) )

The result of performing the processing described above will be a sequence of N intermediate synchronic document instances, DOC _{inter ₀} … DOC _{inter _N−1} .

9.3.3 Synchronic Flow Processing

Subsequent to performing a temporal (synchronic) slice and subsequent remapping of regionally selected content hierarchy, the resulting intermediate synchronic document is subjected to a flow transformation step that produces a rooted flow object tree represented as an XSL FO document instance as defined by [XSL 1.1] , and semantically extended by TT AF specific style properties that have no XSL FO counterpart.

Each intermediate synchronic document produced by 9.3.2 Intermediate Synchronic Document Construction is mapped to an XSL FO document instance, F , as follows:

perform the following ordered sub-steps to create anonymous spans:
1. for each significant text node in a content element, synthesize an anonymous span to enclose the text node, substituting the new anonymous span for the original text node child in its sibling and parent hierarchy;
2. for each contiguous sequence of anonymous spans, replace the sequence with a single anonymous span which contains a sequence of text nodes representing the individual text node children of the original sequence of anonymous spans;
3. for each span element whose child is a single anonymous span, replace the anonymous span with its sequence of child text nodes;
resolve styles according to 8.4.4.4 Style Resolution Process ;
map the tt element to an fo:root element, populated initially with an fo:layout-master-set element that contains a valid fo:simple-page-master that, in turn, contains an fo:region-body child, where the root container extent expressed on the tt element is mapped to page-width and page-height attributes on the fo:simple-page-master element;
map the layout element to an fo:page-sequence element and a child fo:flow element that reference the page master and page region defined by the simple page master produced above;
map each non-empty region element to an fo:block-container element with an absolute-position attribute with value absolute , and where the region's position and extent are mapped to equivalent top , left , width , and height attributes;
for each body , div , and p element that is not associated with a tts:display style property with the value none , map the element to a distinct fo:block element, populating the style properties of fo:block by using the computed style set associated with each original TT AF content element;
for the resulting fo:block formatting object produced in the previous step that corresponds to the body element, synthesize and append to the end of its children an empty fo:block with the following attributes: space-after.optimum , space-after.maximum , and space-after.conditionality , where the value of the former two attributes is the height or width of the containing fo:block-container element, whichever of these is designated as the block progression dimension, and where the value of the last is retain ;
for each span element that is not associated with a tts:display style property with the value none and for each anonymous span that is a child of a p or span element, map the element or sequence of character items to a distinct fo:inline element, populating the style properties of fo:inline by using the computed style set associated with each original TT AF content element or anonymous span;
for each br element that is not associated with a tts:display style property with the value none , map the element to a distinct fo:character element having the following properties:
- character="
  "
- suppress-at-line-break="retain"
for each TT AF style property attribute in some computed style set that has no counterpart in [XSL 1.1] , map that attribute directly through to the relevant formatting object produced by the input TT AF content element to which the style property applies;
optionally, synthesize a unique id attribute on each resulting formatting object element that relates that element to the input element that resulted in that formatting object element;

For each resulting XSL FO document instance DOC _FO , if processing requires presentation on a visual medium, then apply the formatting semantics prescribed by [XSL 1.1] in order to produce an XSL FO area tree that may then be subsequently rendered onto the visual medium.

Note:

In the XSL FO area tree produced by formatting DOC _FO , the page-viewport-area , which is generated by fo:page-sequence element by reference to the sole generated fo:simple-page-master element, corresponds to the root container region defined above in 2 Definitions .

Note:

Due to the possible presence of TT AF style properties or style property values in a given DFXP document instance for which there is no [XSL 1.1] counterpart, the use of a compliant [XSL 1.1] formatting processor is not necessarily sufficient to satisfy the presentation semantics defined by this specification.

9.3.4 Elaborated Example

An example of the processing steps described above is elaborated below, starting with Example – Sample Source Document .

Example – Sample Source Document

<tt tts:extent="640px 480px" xml:lang="en"
  xmlns="http://www.w3.org/2006/10/ttaf1"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <head>
    <layout>
      <region xml:id="r1">
        <style tts:origin="10px 100px"/>
        <style tts:extent="620px 96px"/>
        <style tts:fontSize="40px"/>
        <style tts:fontWeight="bold"/>
        <style tts:backgroundColor="black"/>
        <style tts:color="red"/>
        <style tts:textAlign="center"/>
        <style tts:displayAlign="center"/>
      </region>
      <region xml:id="r2">
        <style tts:origin="10px 300px"/>
        <style tts:extent="620px 96px"/>
        <style tts:fontSize="40px"/>
        <style tts:fontWeight="bold"/>
        <style tts:backgroundColor="black"/>
        <style tts:color="yellow"/>
        <style tts:textAlign="center"/>
        <style tts:displayAlign="center"/>
      </region>
    </layout>
  </head>
  <body xml:id="b1">
    <div xml:id="d1" begin="0s" dur="2s">
      <p xml:id="p1" region="r1">Text 1</p>
      <p xml:id="p2" region="r2">Text 2</p>
    </div>
    <div xml:id="d2" begin="1s" dur="2s">
      <p xml:id="p3" region="r2">Text 3</p>
      <p xml:id="p4" region="r1">Text 4</p>
    </div>
  </body>
</tt>

In the above document, the content hierarchy consists of two divisions, each containing two paragraphs. This content is targeted (selected into) one of two non-overlapping regions that are styled identically except for their position and their foreground colors, the latter of which is inherited by and applies to the (and, in this case, anonymous) spans reparented into the regions.

The following, first intermediate document shows the synchronic state at time interval [0,1), during which time only division d1 is temporally active, and where paragraphs p1 and p2 (and their ancestors) are selected into regions r1 and r2 , respectively.

Note:

The intermediate documents shown below are not valid DFXP document instances, but rather, are representations of possible internal processing states used for didactic purposes.

Example – Intermediate Document – [0s,1s)

<tt tts:extent="640px 480px" xml:lang="en"
  xmlns="http://www.w3.org/2006/10/ttaf1"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <head>
    <layout>
      <region xml:id="r1">
        <style tts:origin="10px 100px"/>
        <style tts:extent="620px 96px"/>
        <style tts:fontSize="40px"/>
        <style tts:fontWeight="bold"/>
        <style tts:backgroundColor="black"/>
        <style tts:color="red"/>
        <style tts:textAlign="center"/>
        <style tts:displayAlign="center"/>
        <body xml:id="b1-1">
          <div xml:id="d1-1">
            <p xml:id="p1">Text 1</p>
          </div>
        </body>
      </region>
      <region xml:id="r2">
        <style tts:origin="10px 300px"/>
        <style tts:extent="620px 96px"/>
        <style tts:fontSize="40px"/>
        <style tts:fontWeight="bold"/>
        <style tts:backgroundColor="black"/>
        <style tts:color="yellow"/>
        <style tts:textAlign="center"/>
        <style tts:displayAlign="center"/>
        <body xml:id="b1-2">
          <div xml:id="d1-2">
            <p xml:id="p2">Text 2</p>
          </div>
        </body>
      </region>
    </layout>
  </head>
</tt>

An XSL FO document instance produced by performing flow processing upon the first intermediate document is shown below.

Example – XSL FO Document – [0s,1s)

<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
  <fo:layout-master-set>
    <fo:simple-page-master master-name="m1"
      page-width="640px" page-height="480px">
      <fo:region-body/>
    </fo:simple-page-master>
  </fo:layout-master-set>
  <fo:page-sequence master-reference="m1">
    <fo:flow flow-name="xsl-region-body">
      <!-- region (r1) -->
      <fo:block-container id="r1" absolute-position="absolute"
        left="10px" top="100px" width="620px" height="96px"
        background-color="black" display-align="center">
        <!-- body (b1) -->
        <fo:block id="b1-1">
          <!-- div (d1) -->
          <fo:block id="d1-1">
            <!-- p (p1) -->
            <fo:block id="p1" text-align="center">
              <fo:inline font-size="40px" font-weight="bold"
              color="red">Text 1</fo:inline>
            </fo:block>
          </fo:block>
          <!-- body's space filler ->
          <fo:block
            space-after.optimum="96px"
            space-after.maximum="96px"
            space-after.conditionality="retain"/>
        </fo:block>
      </fo:block-container>
      <!-- region (r2) -->
      <fo:block-container id="r2" absolute-position="absolute"
        left="10px" top="300px" width="620px" height="96px"
        background-color="black" display-align="center">
        <!-- body (b1) -->
        <fo:block id="b1-2">
          <!-- div (d1) -->
          <fo:block id="d1-2">
            <!-- p (p2) -->
            <fo:block id="p2" text-align="center">
              <fo:inline font-size="40px" font-weight="bold"
              color="yellow">Text 2</fo:inline>
            </fo:block>
          </fo:block>
          <!-- body's space filler ->
          <fo:block
            space-after.optimum="96px"
            space-after.maximum="96px"
            space-after.conditionality="retain"/>
        </fo:block>
      </fo:block-container>
    </fo:flow>
  </fo:page-sequence>
</fo:root>

The following, second intermediate document shows the synchronic state at time interval [1,2), at which time both divisions d1 and d2 are temporally active, and where paragraphs p1 and p4 (and their ancestors) are selected into region r1 and paragraphs p2 and p3 (and their ancestors) are selected into region r2 .

Example – Intermediate Document – [1s,2s)

<tt tts:extent="640px 480px" xml:lang="en"
  xmlns="http://www.w3.org/2006/10/ttaf1"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <head>
    <layout>
      <region xml:id="r1">
        <style tts:origin="10px 100px"/>
        <style tts:extent="620px 96px"/>
        <style tts:fontSize="40px"/>
        <style tts:fontWeight="bold"/>
        <style tts:backgroundColor="black"/>
        <style tts:color="red"/>
        <style tts:textAlign="center"/>
        <style tts:displayAlign="center"/>
        <body xml:id="b1-1">
          <div xml:id="d1-1">
            <p xml:id="p1">Text 1</p>
          </div>
          <div xml:id="d2-1">
            <p xml:id="p4">Text 4</p>
          </div>
        </body>
      </region>
      <region xml:id="r2">
        <style tts:origin="10px 300px"/>
        <style tts:extent="620px 96px"/>
        <style tts:fontSize="40px"/>
        <style tts:fontWeight="bold"/>
        <style tts:backgroundColor="black"/>
        <style tts:color="yellow"/>
        <style tts:textAlign="center"/>
        <style tts:displayAlign="center"/>
        <body xml:id="b1-2">
          <div xml:id="d1-2">
            <p xml:id="p2">Text 2</p>
          </div>
          <div xml:id="d2-2">
            <p xml:id="p3">Text 3</p>
          </div>
        </body>
      </region>
    </layout>
  </head>
</tt>

The following, third intermediate document shows the synchronic state at time interval [2,3), at which time only division d2 is temporally active, and where paragraphs p4 and p3 (and their ancestors) are selected into regions r1 and r2 , respectively.

Example – Intermediate Document – [2s,3s)

<tt tts:extent="640px 480px" xml:lang="en"
  xmlns="http://www.w3.org/2006/10/ttaf1"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <head>
    <layout>
      <region xml:id="r1">
        <style tts:origin="10px 100px"/>
        <style tts:extent="620px 96px"/>
        <style tts:fontSize="40px"/>
        <style tts:fontWeight="bold"/>
        <style tts:backgroundColor="black"/>
        <style tts:color="red"/>
        <style tts:textAlign="center"/>
        <style tts:displayAlign="center"/>
        <body xml:id="b1-1">
          <div xml:id="d2-1">
            <p xml:id="p4">Text 4</p>
          </div>
        </body>
      </region>
      <region xml:id="r2">
        <style tts:origin="10px 300px"/>
        <style tts:extent="620px 96px"/>
        <style tts:fontSize="40px"/>
        <style tts:fontWeight="bold"/>
        <style tts:backgroundColor="black"/>
        <style tts:color="yellow"/>
        <style tts:textAlign="center"/>
        <style tts:displayAlign="center"/>
        <body xml:id="b1-2">
          <div xml:id="d2-2">
            <p xml:id="p3">Text 3</p>
          </div>
        </body>
      </region>
    </layout>
  </head>
</tt>

9.4 Line Layout

The semantics of line layout, including line breaking, defined by [XSL 1.1] apply to the performance of the composition and layout of lines for presentation processing of a document instance on a visual medium.

If a profile that applies to a document instance requires use of the #lineBreak-uax14 feature (i.e., the value attribute for the feature is specified as use ), then the recommendations defined by Line Breaking Algorithm [UAX14] apply when performing line layout on the content of the document instance.

10 Timing

This section specifies the timing matter of the core vocabulary catalog, where timing is to be understood as a separable layer of information that applies to content and that denotes authorial intentions about the temporal presentation of that content.

10.1 Timing Element Vocabulary

No timing related element vocabulary is defined for use in the core vocabulary catalog.

10.2 Timing Attribute Vocabulary

This section defines the following basic timing attributes for use with timed elements:

10.2.1 begin
10.2.2 end
10.2.3 dur

In addition, this section defines the 10.2.4 timeContainer attribute for use with timed elements that serve simultaneously as timing containers.

10.2.1 begin

The begin attribute is used to specify the begin point of a temporal interval associated with a timed element. If specified, the value of a begin attribute must adhere to a <timeExpression> specification as defined by 10.3.1 <timeExpression> .

The begin point of a temporal interval is included in the interval; i.e., the interval is left-wise closed.

The semantics of the begin attribute are those defined by [SMIL 2.1] , § 10.4.1, while taking into account any overriding semantics defined by this specification.

10.2.2 end

The end attribute is used to specify the ending point of a temporal interval associated with a timed element. If specified, the value of an end attribute must adhere to a <timeExpression> specification as defined by 10.3.1 <timeExpression> .

The ending point of a temporal interval is not included in the interval; i.e., the interval is right-wise open.

The presentation effects of a non-empty active temporal interval include the frame immediately prior to the frame (or tick) equal to or immediately following the time specified by the ending point, but do not extend into this latter frame (or tick).

Note:

For example, if an active interval is [10s,10.33333s), and the frame rate is 30 frames per second, then the presentation effects of the interval are limited to frames 300 through 309 only (assuming that 0s corresponds with frame 0). The same holds if the active interval is specified as [300f,310f).

The semantics of the end attribute are those defined by [SMIL 2.1] , § 10.4.1, while taking into account any overriding semantics defined by this specification.

10.2.3 dur

The dur attribute is used to specify the duration of a temporal interval associated with a timed element. If specified, the value of a dur attribute must adhere to a <timeExpression> specification as defined by 10.3.1 <timeExpression> .

Note:

When the clock-time form of a <timeExpression> specification is used with a dur attribute, it is intended to be interpreted as a difference between two implied clock time expressions.

When a TT AF document instance specifies the use of the smpte time base and discontinuous marker mode, the dur attribute must not be specified on any element.

The semantics of the dur attribute are those defined by [SMIL 2.1] , § 10.4.1, while taking into account any overriding semantics defined by this specification.

Note:

In the context of the subset of [SMIL 2.1] semantics supported by this specification, the active duration of an element that specifies both end and dur attributes is equal to the lesser of the value of the dur attribute and the difference between the value of the end attribute and the element's begin time.

10.2.4 timeContainer

The timeContainer attribute is used to specify a local temporal context by means of which timed child elements are temporally situated.

If specified, the value of a timeContainer attribute must be one of the following:

par
seq

If the time container semantics of an element instance is par , then the temporal intervals of child elements are considered to apply in parallel, i.e., simultaneously in time. Furthermore, the specification of the time interval of each child element is considered to be relative to the temporal interval of the container element instance.

If the time container semantics of an element instance is seq , then the temporal intervals of child elements are considered to apply in sequence, i.e., sequentially in time. Furthermore, the specification of the time interval of each child element is considered to be relative to the temporal interval of its sibling elements, unless it is the first child element, in which case it is considered to be relative to the temporal interval of the container element instance.

Each time container is considered to constitute an independent time base, i.e., time coordinate system.

If a timeContainer attribute is not specified on an element that has time container semantics, then par time container semantics must apply.

Time container semantics applies only to the following element types:

body
div
p
region
span

The semantics of parallel and sequential time containment are those defined by [SMIL 2.1] , § 10.3.2, while taking into account any overriding semantics defined by this specification.

10.3 Time Value Expressions

Timing attribute values include the use of the following expressions:

10.3.1 <timeExpression>

10.3.1 <timeExpression>

A <timeExpression> is used to specify a coordinate along some time base, where the applicable time base is determined by the ttp:timeBase parameter.

Note:

See 6.2.11 ttp:timeBase , ~~6.2.3~~ 6.2.4 ttp:frameRate , 6.2.9 ttp:subFrameRate , and 6.2.10 ttp:tickRate for further information on explicit specification of time base, frame rate, sub-frame rate, and tick rate.

Syntax Representation – <timeExpression>

<timeExpression>
  : clock-time
  | offset-time
clock-time
  : hours ":" minutes ":" seconds ( fraction | ":" frames ( "." sub-frames )? )?
offset-time
  : time-count fraction? metric
hours
  : <digit> <digit>
  | <digit> <digit> <digit>+
minutes | seconds
  : <digit> <digit>
frames
  : <digit> <digit>
  | <digit> <digit> <digit>+
sub-frames
  : <digit>+
fraction
  : "." <digit>+
time-count
  : <digit>+
metric
  : "h"                 // hours
  | "m"                 // minutes
  | "s"                 // seconds
  | "ms"                // milliseconds
  | "f"                 // frames
  | "t"                 // ticks

If a <timeExpression> is expressed in terms of a clock-time , then leading zeroes are used when expressing hours, minutes, seconds, and frames less than 10. Minutes are constrained to the range [0…59], while seconds are constrained to [0…60], where the value 60 applies only to leap seconds.

If a <timeExpression> is expressed in terms of a clock-time and a frames term is specified, then the value of this term must be constrained to the interval [0… F-1 ], where F is the frame rate determined by the the ttp:frameRate parameter as defined by ~~6.2.3~~ 6.2.4 ttp:frameRate .

If a <timeExpression> is expressed in terms of a clock-time and a sub-frames term is specified, then the value of this term must be constrained to the interval [0… S-1 ], where S is the sub-frame rate determined by the the ttp:subFrameRate parameter as defined by 6.2.9 ttp:subFrameRate .

10.4 Time Intervals

The semantics of time containment, durations, and intervals defined by [SMIL 2.1] apply to the interpretation of like-named timed elements and timing vocabulary defined by this specification, given the following constraints:

The implicit duration of an anonymous span is defined as follows: if the anonymous span's parent time container is a parallel time container, then the implicit duration is equivalent to the indefinite duration value as defined by [SMIL 2.1] ; if the anonymous span's parent time container is a sequential time container, then the implicit duration is equivalent to zero.
The implicit duration of a body , div , p , or span element is determined in accordance to (1) whether the element is a parallel or sequential time container, and (2) the semantics of [SMIL 2.1] as applied to these time containers.
The implicit duration of the region element is defined to be equivalent to the indefinite duration value as defined by [SMIL 2.1] .
If the governing time mode is media or smpte with mode continuous , then time expressions must be interpreted as equivalent to offset ~~clock values related to the associated media time line.~~ based timing in [SMIL 2.1] ,namely, as offsets from an implicit syncbase .
If the governing time mode is smpte with mode discontinuous , then time expressions must be interpreted as equivalent to marker values produced by an external marker event source, in which case all time expressions are equivalent to event based timing in [SMIL 2.1] .
If the governing time mode is clock , then time expressions must be interpreted as equivalent to wallclock time expressions in [SMIL 2.1] , where the applicable wallclock used is determined by the clock mode parameter.

11 Animation

This section specifies the animation matter of the core vocabulary catalog, where animation is to be understood as a separable layer of information that combines timing and styling in order to denote authorial intention about (temporally) dynamic styling of content.

11.1 Animation Element Vocabulary

The following elements specify the structure and principal animation aspects of a document instance:

11.1.1 set

11.1.1 set

The set element is used as a child element of a content element or a region element in order to express a discrete change of some style parameter value that applies over some time interval.

The set element accepts as its children zero or more elements in the Metadata.class element group.

XML Representation – Element Information Item: set

<set
  begin = <timeExpression>
  dur = <timeExpression>
  end = <timeExpression>
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {a single attribute in TT Style namespace}
  {any attribute not in default or any TT namespace}>
  Content: Metadata.class*
</set>

Note:

The use of multiple set element children may be used to effect fade and position transitions.

An example of using the set element to animate content styling is illustrated below:

Example Fragment – Content Style Animation

...
<p dur="5s" tts:color="yellow">
<set begin="1s" dur="1s" tts:color="red"/>
<set begin="2s" dur="1s" tts:color="green"/>
<set begin="3s" dur="1s" tts:color="red"/>
Text with Flashing Colors!
</p>
...

Note:

In the above example, the foreground color of the content "Text with Flashing Colors" is animated from yellow, to red, to green, to red, then back to yellow over a 5 second period.

An example of using the set element to animate region styling is illustrated below:

Example Fragment – Region Style Animation

<tt xml:lang="" xmlns="http://www.w3.org/2006/10/ttaf1"
    xmlns:ttp="http://www.w3.org/2006/10/ttaf1#parameter"
    xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling"
    ttp:cellResolution="40 16">
    <head>
      <layout>
        <region xml:id="r1" timeContainer="seq">
          <set dur="10s" tts:origin=" 8c 14c"/>
          <set dur="2s"  tts:origin=" 2c  2c"/>
          <set dur="3s"  tts:origin=" 8c 14c"/>
          <set dur="2s"  tts:origin="14c  4c"/>
          <set dur="10s" tts:origin=" 8c 14c"/>
          <style tts:extent="24c 2c"/>
        </region>
      </layout>
    </head>
    <body region="r1">...</body>
</tt>

Note:

In the above example, the root container region is divided into a cell grid of 40 columns and 16 rows. A region, r1 , with dimensions of 24 columns and 2 rows is then positioned within the root container region, with its position varying over time in order to create an effect of moving the region, which may be desirable so as to avoid obscuring characters in an underlying video with captions.

Note:

The semantics of the set element are based upon that defined by [SMIL 2.1] , § 3.5.2.

11.2 Animation Attribute Vocabulary

No animation related attribute vocabulary is defined for use in the core vocabulary catalog.

12 Metadata

This section specifies the metadata matter of the core vocabulary catalog, where metadata is to be understood as a separable layer of information that applies to parameters, content, style, layout, timing, and even metadata itself, where the information represented by metadata takes one of two forms: (1) metadata defined by this specification for standardized use in a document instance, and (2) arbitrary metadata defined outside of the scope of this specification, whose use and semantics depend entirely upon an application's use of TT AF content.

12.1 Metadata Element Vocabulary

The 12.1.1 metadata element serves as a generic container element for grouping metadata information.

In addition, the following elements, all defined in the TT Metadata Namespace, provide standard representations for common metadata that is expected to be commonly used in a document instances:

12.1.2 ttm:title
12.1.3 ttm:desc
12.1.4 ttm:copyright
12.1.5 ttm:agent
12.1.6 ttm:name
12.1.7 ttm:actor

12.1.1 metadata

The metadata element functions as a generic container for metadata information.

Metadata information may be expressed by a metadata element in one of two (non-mutually exclusive) manners: (1) by specifying one or more metadata attributes on the metadata element, and (2) by specifying one or more child elements in the metadata element that express metadata. Both types of metadata are referred to in this document as metadata items .

XML Representation – Element Information Item: metadata

<metadata
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute in TT Metadata namespace}
  {any attribute not in default or any TT namespace}>
  Content: ({any element in TT Metadata namespace}|{any element not in any TT namespace})*
</metadata>

Note:

The meaning of a specific metadata item must be evaluated in the context of where it appears. The core vocabulary catalog permits an arbitrary number of metadata element children of any content element type except for the tt element. See specific element vocabulary definitions for any constraints that apply to such usage.

The use of document metadata is illustrated by the following example.

Example Fragment – Document Metadata

...
<head>
  <metadata xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata">
    <ttm:title>Document Metadata Example</ttm:title>
    <ttm:desc>This document employs document metadata.</ttm:desc>
  </metadata>
</head>
...

The use of element metadata is illustrated by the following example.

Example Fragment – Element Metadata

...
<div>
  <metadata xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata">
    <ttm:title>Chapter 6 – Sherlock Holmes Gives a Demonstration</ttm:title>
    <ttm:desc>Holmes shows Watson how the murderer entered the window.</ttm:desc>
  </metadata>
</div>
...

The use of metadata attribute items is illustrated by the following example.

Example Fragment – Foreign Metadata Attribute Items
... <div xmlns:ext="http://foo.bar.example.org/ttaf1#metadata"> <metadata ext:ednote="remove this division prior to publishing"/> </div> ...

Note:

In the above example, a global attribute from a foreign (external) namespace is used to express a metadata attribute that applies semantically to the containing div element. Note that the attribute may also be expressed directly on the div element; however, in this case the author wishes to segregate certain metadata attributes by expressing them indirectly on metadata elements.

The use of foreign element metadata is illustrated by the following example.

Example Fragment – Foreign Element Metadata

...
<metadata
  xmlns:dc="http://purl.org/dc/elements/1.1/"
  xmlns:dcterms="http://purl.org/dc/terms/"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <dc:title>Foreign Element Metadata Example</dc:title>
  <dc:description>Express metadata using elements in foreign namespace.</dc:description>
  <dc:format xsi:type="dcterms:IMT">application/ttaf+xml</dc:format>
</metadata>
...

Note:

In the above example, a number of elements defined by the Dublin Core metadata vocabulary are used to express document level metadata.

12.1.2 ttm:title

The ttm:title element is used to express a human-readable title of a specific element instance.

XML Representation – Element Information Item: ttm:title
<ttm:title xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute not in default or any TT namespace}> Content: #PCDATA </ttm:title>

Note:

No specific use of the ttm:title element is defined by this specification.

Examples of the ttm:name ttm: title element are shown above in Example Fragment – Document Metadata and Example Fragment – Element Metadata .

12.1.3 ttm:desc

The ttm:desc element is used to express a human-readable description of a specific element instance.

XML Representation – Element Information Item: ttm:desc
<ttm:desc xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute not in default or any TT namespace}> Content: #PCDATA </ttm:desc>

Note:

No specific use of the ttm:desc element is defined by this specification.

Examples of the ttm:desc element are shown above in Example Fragment – Document Metadata and Example Fragment – Element Metadata .

12.1.4 ttm:copyright

The ttm:copyright element is used to express a human-readable copyright that applies to some scoping level.

A copyright statement that applies to a document as a whole should appear as a child of the head element.

XML Representation – Element Information Item: ttm:copyright
<ttm:copyright xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute not in default or any TT namespace}> Content: #PCDATA </ttm:copyright>

Note:

No specific use of the ttm:copyright element is defined by this specification.

12.1.5 ttm:agent

The ttm:agent element is used to define an agent for the purpose of associating content information with an agent who is involved in the production or expression of that content.

The ttm:agent element accepts as its children zero or more ttm:name elements followed by zero or one ttm:actor element.

At least one ttm:name element child should be specified that expresses a name for the agent, whether it be the name of a person, character, group, or organization.

XML Representation – Element Information Item: ttm:agent

<ttm:agent
  type = (person|character|group|organization|other)
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute not in default or any TT namespace}>
  Content: ttm:name*, ttm:actor?
</ttm:agent>

A type attribute must be specified on each ttm:agent element, and, if specified, must have one of the following values:

person
character
group
organization
other

If the value of the type attribute is character , then the ttm:agent element instance should specify a ttm:actor child that specifies the agent that plays the role of the actor.

A ttm:agent metadata item is considered to be significant only when specified as a child of the head element or as a child of a metadata element child of the head element.

Note:

A ttm:agent element instance is typically referenced using a ttm:agent attribute on a content element.

Note:

If a character agent is played by multiple actors, then multiple character agents may be specified (and referenced) wherein different definitions of the character specify different actors.

The use of agent metadata is illustrated by the following example.

Example Fragment – Agent Metadata

<tt xml:lang="en" xmlns="http://www.w3.org/2006/10/ttaf1" xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata">
  <head>
    <ttm:agent xml:id="connery" type="person">
      <ttm:name type="family">Connery</ttm:name>
      <ttm:name type="given">Thomas Sean</ttm:name>
      <ttm:name type="alias">Sean</ttm:name>
      <ttm:name type="full">Sir Thomas Sean Connery</ttm:name>
    </ttm:agent>
    <ttm:agent xml:id="bond" type="character">
      <ttm:name type="family">Bond</ttm:name>
      <ttm:name type="given">James</ttm:name>
      <ttm:name type="alias">007</ttm:name>
      <ttm:actor agent="connery"/>
    </ttm:agent>
  </head>
  <body>
    <div>
      ...  
      <p ttm:agent="bond">I travel, a sort of licensed troubleshooter.</p>
      ...  
    </div>
  </body>
</tt>

Note:

In the above example, two agents, a real (person) agent, Sean Connery, and a fictitious (character) agent, James Bond, are defined, where the latter is linked to the former by means of the a ttm:actor element. A reference is then made from content (the p element) to the character agent associated with (responsible for producing) that content. Note that in this example the ttm:agent metadata items are specified as immediate children of the document's head element rather than being placed in a container metadata element.

12.1.6 ttm:name

The ttm:name element is used to specify a name of a person, character, group, or organization.

XML Representation – Element Information Item: ttm:name

<ttm:name
  type = (full|family|given|alias|other)
  xml:id = ID
  xml:lang = string
  xml:space = (default|preserve)
  {any attribute not in default or any TT namespace}>
  Content: #PCDATA
</ttm:name>

A type attribute must be specified on each ttm:name element, and, if specified, must have one of the following values:

full
family
given
alias
other

The relationship between the type of a name and the syntactic expression of the name is not defined by this specification.

Two examples of the ttm:name element are shown above in Example Fragment – Agent Metadata .

12.1.7 ttm:actor

The ttm:actor element is used to link the definition of a (role-based) character agent with another agent that portrays the character.

XML Representation – Element Information Item: ttm:actor
<ttm:actor agent = IDREF xml:id = ID xml:lang = string xml:space = (default\|preserve) {any attribute not in default or any TT namespace}> Content: EMPTY </ttm:actor>

The agent attribute of a ttm:actor element must reference a ttm:agent element that denotes the person, group, or organization acting the part of a character.

An example of the ttm:actor element is shown above in Example Fragment – Agent Metadata .

12.2 Metadata Attribute Vocabulary

This section specifies the following attributes in the TT Metadata Namespace for use with the metadata element and with certain content elements:

12.2.1 ttm:agent
12.2.2 ttm:role

Note:

Only certain metadata item attributes may be used with content elements. See the definitions of content elements to determine permissible usage.

12.2.1 ttm:agent

The ttm:agent attribute takes an IDREFS value, and is used with certain content elements to designate the agents that perform or are involved in the performance of the content.

If specified, a ttm:agent attribute must reference ttm:agent element instances that appear as a descendent of the same document instance as that of the referring element.

An example of the ttm:agent attribute is shown above in Example Fragment – Agent Metadata .

12.2.2 ttm:role

The ttm:role attribute may be used by a content author to express the roles, functions, or characteristics of some content element that is so labeled.

If specified, the value of this attribute must adhere to the following syntax, where the syntactic element S must adhere to production [3] S as defined by [XML 1.0] § 2.3:

Syntax Representation – ttm:role

ttm:role
  role ( S role )*
role
  : "action"
  | "caption"
  | "description"
  | "dialog"
  | "expletive"
  | "kinesic"
  | "lyrics"
  | "music"
  | "narration"
  | "quality"
  | "sound"
  | "source"
  | "suppressed"
  | "reproduction"
  | "thought"
  | "title"
  | "transcription"
  | extension-role
extension-role
  : "x-" token-char+
token-char
  : { XML NameChar }    // XML 1.1 Production [4a]

Note:

All values of ttm:role that do not start with the prefix x- are reserved for future standardization.

A Reduced XML Infoset

This appendix is normative.

For the purposes of this specification, a Reduced XML Infoset is an XML Information Set [XML InfoSet] that consists of only the following information items and information item properties:

A.1 Document Information Item

[document element]

A.2 Element Information Item

[namespace URI]
[local name]
[children]
[attributes]

Child information items [children] are reduced to only element and character information items.

A.3 Attribute Information Item

[namespace URI]
[local name]
[normalized value]

A.4 Character Information Item

[character code]

Contiguous character information items are not required to be represented distinctly, but may be aggregated (chunked) into a sequence of character codes (i.e., a character string).

B Dynamic Flow Processing Model

This appendix is normative.

This appendix specifies a dynamic flow processing model that is used to present content in a region whose tts:overflow property is assigned a value of dynamic .

B.1 Introduction

This sub-section is non-normative.

Dynamic flow provides a mechanism by means of which content may be flowed through a presentation region over time where the rate of presentation is dynamically determined by a presentation processor based upon the region's extent, the textual content to be presented in the region, the formatting styles applied to this content, and a set of parameters that control in-flow and out-flow rates of content.

It is expected that this mechanism will be used by authors in a variety of circumstances in order to specify behavior that would otherwise be impossible or impractical to pre-compute at authoring time, since, for example, a region's absolute size or the font metrics used to present content may not be known at authoring time. In certain real-time streaming contexts, even the content is not known at authoring time, but is only known at time of streaming.

In describing dynamic flow, the flow process is logically divided into two types of flow operations:

fill into – causes new content to consume extent in the designated presentation region;
clear out – causes content presently consuming extent in the designated presentation region to no longer consume extent.

Each region subject to dynamic flow processing may be modeled in terms of:

the region with a definite extent, into which content is to be flowed;
a content buffer consisting of a sequence of content blocks, each of which consists of a sequence of content inlines (spans), where each block and inline has a computed style set, and where an inline has a (possibly empty) sequence of characters that express the textual content of the inline;
two independent flow operation single-shot timers: a fill timer and a clear timer;
a set of state parameters that includes:
1. fill unit , as specified by the flowUnit argument of the in() flow function;
2. fill style , as specified by the flowStyle argument of the in() flow function;
3. reflow unit , which is set to the same value as the clear unit parameter;
4. reflow style , which is set to the same value as the clear style parameter;
5. clear unit , as specified by the flowUnit argument of the out() flow function;
6. clear style , as specified by the flowStyle argument of the out() flow function;
7. fill interval , as specified by the fill() flow interval function;
8. clear interval , as specified by the clear() flow interval function;
9. computed fill interval , as determined by the flow interval timing calculation below;
10. computed clear interval , as determined by the flow interval timing calculation below;
11. last fill time , the time at which the last fill operation occurred;
12. last clear time , the time at which the last clear operation occurred;
13. dynamic flow lock , a synchronization primitive;

Except for the computed fill and clear interval parameters, and unless the tts:dynamicFlow property is animated, the flow interval state parameters enumerated above are nominally static and specified at authoring time. If the tts:dynamicFlow property is animated, then these nominally static parameters remain static between animation intervals.

B.2 Flow Buffer

Each region which is assigned a tts:overflow property with the value dynamic is associated with a flow buffer , ~~whose~~ the implementation of which is not defined by this specification.

The content of a flow buffer is defined to be equivalent (in form) to the content of an fo:block-container element produced by 9.3.3 Synchronic Flow Processing , and represents content that is awaiting, but has not yet been flowed into (made visible in) the presentation region with which the flow buffer is associated.

Note:

In the context of dynamic flow processing, the temporal extent of a region's flow buffer is assumed to persist over a period that includes multiple instantiations of synchronous intermediate documents, as described by 9.3.3 Synchronic Flow Processing . This is feasible since the set of regions associated with a DFXP document instance is fixed and determined statically at authoring time.

The temporal content of a flow buffer is related to the performance of 9.3 Region Layout and Presentation as follows:

At the time a dynamically flowed presentation region becomes temporally active, its flow buffer is reset to the empty state;
If times T _k and T _k+1 are two immediately adjacent time coordinates at which synchronic region construction occurs, with T _k ≤T _k+1 , then compute the difference between the content produced for use in the region between time T _k and time T _k+1 , characterizing the difference as one of the following:
1. no difference present;
2. difference present, but only before the logical content position that corresponds with the most logically prior content presently visible in the region;
3. difference present, but only between the logical content positions that correspond with the most logically prior and subsequent content presently visible in the region;
4. difference present, but only after the logical content position that corresponds with the most logically subsequent content presently visible in the region;
5. difference present, but not limited to before, between, or after the logical content positions that correspond with the most logically prior and subsequent content presently visible in the ~~region;~~ region.
If any one of the conditions 2a, 2b, and 2c applies, then do not change the flow buffer.
If condition 2d applies, then replace at time T _k+1 the affected content of the flow buffer with the new content (in part or in whole) that corresponds with time T _k+1 such that the logical content position of the content that corresponds with the start of the flow buffer does not change with respect to the corresponding logical content position of the previous content.
If condition 2e applies, then subdivide the new content that corresponds with time T _k+1 into two parts: (1) that part that wholly precedes the logical content position that corresponds with the most logically subsequent content presently visible in the region, and (2) that part that corresponds with or wholly follows the logical content position that corresponds with the most logically subsequent content presently visible in the region, then ignore the first part and process the second part in the same manner as if condition 2d had originally applied.
If after performing the above steps the flow buffer is non-empty, then perform the following steps:
1. If, due to style property animation, the dynamic flow state parameters for the region have changed since last performing this procedure, then re-perform the process described in B.3 Flow Interval Timing Calculation , then reset both fill and clear timers to their inactive state.
2. If using automatic flow interval timing, then re-perform the process described in B.3 Flow Interval Timing Calculation .
3. If the fill timer is not ~~active,~~ active and if the current value of the numeric value , then reset the fill timer to the current value of the computed fill ~~interval.~~ interval ;
4. If the fill timer is not active, if the current value of the computed fill interval is the token value break ,and if the flow buffer contains a retained line break, then simulate the effects of fill timer expiration by performing the processing described in B.5.1 Fill Timer .

In the procedure described above, the content of a flow buffer at time T _k is considered to be significantly different from the content of the same flow buffer at time T _k+1 if the set of glyph areas that would be produced by performing synchronic flow processing on the intermediate synchronic document at time T _k differs from the set of glyph areas that would be produced by performing synchronic flow processing on the intermediate synchronic document at time T _k+1 in any of the following ways:

the number of glyph areas are different;
the (positionally) ordered sets of glyphs associated with the two sets of glyph areas are different;
the positions assigned to the glyph images associated with the two sets of glyph areas are different;

Note:

Other potential, but insignificant differences (as far as flow buffer processing is concerned) between the two sets of glyph areas are ignored, including (among others) differences in: background color, foreground color, glyph decoration(s), actual presentation order of glyphs (independently from their assigned position).

If the value of a style property assigned to content awaiting in a flow buffer or already dynamically flowed into a presentation region is changed due to animation or other temporal effects, and that style property change is not otherwise construed as a significant difference between temporal flow buffer states as described above, then the semantic, presentation effects of that change of value still apply.

In the procedure described above, the phrase logical content position refers to a tuple [active duration begin time, active duration end time, character information item index], where the active duration begin and end times refer to the computed active time interval for which the character information item is considered active, where the character information item index refers to the logical index of the character information item in the synchronic intermediate document instance associated with the character information item, and where the logical index of the character information item refers to the enumeration index that results by performing a post-order traversal enumeration of the character information items contained in the region sub-tree (of the synchronic intermediate document instance) associated with the presentation region of the current flow buffer.

A logical content position P ₀ is considered to be prior to (before) logical content position P ₁ if (1) the active duration begin time of P ₀ is temporally prior to the active duration begin time of P ₁ , or (2) the active duration begin times of P ₀ and P ₁ are equal and the character information item index of P ₀ precedes (is less than) the character information item index of P ₁ . Similarly, a logical content position P ₀ is considered to be subsequent to (after) logical content position P ₁ if (1) the active duration begin time of P ₀ is temporally subsequent to the active duration begin time of P ₁ , or (2) the active duration begin times of P ₀ and P ₁ are equal and the character information item index of P ₀ follows (is greater than) the character information item index of P ₁ . If a logical content position P ₀ and a logical content position P ₁ are neither prior nor subsequent to one another, then they are considered to be the same logical content position (in the present context).

B.3 Flow Interval Timing Calculation

Flow interval timing is either statically specified at authoring time or is dependent upon animation of the tts:dynamicFlow style property or upon the content of the flow buffer or the presentation region or both, in which case timing is recomputed dynamically upon changes to style property, the content of the flow buffer, or the presentation region.

B.3.1 Computed Fill Timing Interval

The computed fill timing interval from time T _k up to but not including T _k+1 is determined as follows, where the meaning of T _k and T _k+1 is as described above:

If the value of the fill interval parameter is a definite duration, then use this duration as the computed fill interval;
otherwise, if the value of the fill interval parameter is a definite rate, then the computed fill interval is equal to the inverse of the specified rate (in fill units per second);
otherwise, if the value of the fill interval parameter is auto , then the computed fill interval is equal to the difference between the time coordinate associated with the most temporally prior beginning point of an active duration of some content unit present in the flow buffer at time T _k and the most temporally subsequent ending point of an active duration of some content unit present in the flow buffer at time T _k divided by the number of fill units currently available in the flow buffer at time T _k ;
otherwise, if the value of the fill interval parameter is break ,then the computed fill interval is the special token value break .

B.3.2 Computed Clear Timing Interval

The computed clear timing interval from time T _k up to but not including T _k+1 is determined as follows, where the meaning of T _k and T _k+1 is as described above:

If the value of the clear interval parameter is a definite duration, then use this duration as the computed clear interval;
otherwise, if the value of the clear interval parameter is a definite rate, then the computed clear interval is equal to the specified rate (in clear units per second);
otherwise, if the value of the clear interval parameter is auto , then the computed clear interval is equal to the difference between the time coordinate associated with the most temporally prior beginning point of an active duration of some content unit present in the presentation region at time T _k and the most temporally subsequent ending point of an active duration of some content unit present in the presentation region at time T _k divided by the number of clear units currently available in the presentation region at time T _k ;
otherwise, if the value of the clear interval parameter is break ,then the computed clear interval is the special token value break .

B.4 Flow Operations

Flow operations perform the filling, reflowing, and clearing of formatted content into, within, and from a presentation region undergoing dynamic flow processing.

When performing flow operations, the fill unit state parameters that apply to these operations determine which logical content and which formatted content are affected. If a fill unit is expressed in terms of logical content units, then the logical content corresponds in turn with the formatted content generated by this logical content; if expressed in terms of formatted content units, then the formatted content corresponds in turn with the logical content that generates this formatted content.

Flow operations apply simultaneously to logical content and to its corresponding formatted content. In the context of the presentation region, fill, reflow, and clear operations operate on formatted content units (glyph and line areas); however, in the context of the flow buffer, fill, reflow, and clear operations operate on logical content units (character information items). Because logical content units and formatted content units are deterministically related to one another, an operation upon logical units can always be described in terms of operations on formatted units, and vice-versa.

Note:

In general, there is not a one-to-one correspondence between logical content units and formatted content units. A single logical content unit often corresponds to multiple formatted content units. Furthermore, a single formatted content unit may correspond with multiple logical content units. For example, a single character information item may correspond to multiple glyph areas; likewise, a single glyph area may correspond to multiple character information items.

For the purpose of performing line breaking in the context of dynamic flow processing, fill, reflow, and clear flow unit boundaries must be interpreted as potential legal line break opportunity regardless of other constraints.

When effecting the result of a flow operation on a presentation region, the direction of (apparent) translation of formatted content is determined by the nature of the affected formatted content element. If the affected formatted content unit is a glyph area, then it is translated in the inline progression direction that applies to the nearest immediate ancestor inline or block area, and it is translated in a direction towards the start edge of this ancestor area. If the affected formatted content unit is a line, then it is translated in the block progression direction that applies to the nearest immediate ancestor block, and it is translated in a direction towards the before edge of this ancestor area.

If the smooth flow style applies to a flow operation, then the direction of (apparent) translation of pixels that belong to the affected formatted content follows the direction of translation of the formatted content units as determined above.

B.4.1 Fill Operation

A fill operation causes the following ordered steps to be performed:

reset the last fill time to the current value of the flow timers timeline;
remove sufficient logical content from the beginning of the flow buffer to constitute (or compose) a fill unit ;
format the content removed from the flow buffer in the previous step in order to create a sequence of glyph areas or a sequence of line areas each containing a sequence of glyph areas;
append the sequence of areas produced in the previous step to the sequence of areas currently associated with the presentation region, where new glyph areas are appended to the current line area and new line areas are appended to the sequence of line areas;
cause the newly appended areas to be made visible according to the fill style state parameter in force;
if the clear timer is not ~~active,~~ active and the current value of the computed clear interval is a numeric value , then reset the clear timer to the current value of the computed clear interval ;
if the current value of the computed fill interval is a numeric value, then reset the fill timer to the current value of the computed fill interval .

Note:

In certain cases, it may be necessary to retain logical content removed from the flow buffer in an intermediate, holding buffer. This will be the case when the smallest logical content unit of a flow buffer, namely, a character information item, generates more than one formatted fill unit. For example, certain characters are rendered using more than one glyph area. If the fill unit is glyph , then such a character needs to be retained (in such a holding buffer) until all generated glyphs are consumed.

B.4.2 Reflow Operation

A reflow operation causes the following ordered steps to be performed:

translate glyph areas or line areas that correspond with a reflow unit of formatted content that follows (in inline or block progression dimension order) the space cleared by the immediately preceding clear operation to a new position such that the glyph area that corresponds to the most logically prior content is aligned with the before and start edges of the presentation region, and where the translation adheres to the reflow style state parameter in force.

Note:

If a reflow unit is based on logical content units, then "reflow unit of formatted content" refers to the logical content that generates the glyph and line areas of formatted content that are being translated within the presentation region. In contrast, if a reflow unit is based on formatted content units, then "reflow unit of formatted content" refers directly to the generated glyph and line areas of formatted content.

B.4.3 Clear Operation

A clear operation causes the following ordered steps to be performed:

reset the last clear time to the current value of the flow timers timeline;
remove glyph areas or line areas that correspond with a clear unit of formatted content from the starting edge or the before edge of the presentation region in inline or block progression direction, respectively, applying the clear style state parameter in force.

Note:

If a clear unit is based on logical content units, then "clear unit of formatted content" refers to the logical content that generates the glyph and line areas of formatted content that are being cleared from the presentation region. In contrast, if a clear unit is based on formatted content units, then "clear unit of formatted content" refers directly to the generated glyph and line areas of formatted content.

B.4.4 Combined Flow Operation

A combined flow operation causes the following ordered steps to be performed:

if the presentation region contains sufficient formatted content to compose a clear unit , then perform the processing described in B.4.3 Clear Operation ;
if (1) the space created by the above clear operation is sufficient to accept a reflow unit and (2) the presentation region contains sufficient formatted content to compose a reflow unit , then perform the processing described in B.4.2 Reflow Operation ;
if (1) the difference between the current value of the flow timers timeline and the last fill time is greater than or equal to the current value of the computed fill interval, (2) the presentation region contains sufficient space to accept a fill unit , and (3) the flow buffer contains sufficient content to compose a fill unit , then perform the processing described in B.4.1 Fill Operation ;

If more than one of the clear, reflow or fill operations would be performed by the above steps, then the visual rendering of these operations should be performed in such a manner as to reduce or eliminate delays between the completion of one operation and the start of the next operation.

Note:

For example, if the applicable clear, reflow, and fill styles are indicated as smooth flow style, then it should appear that the clear, reflow, and fill units are simultaneously translated in a continuous, smooth translation.

B.5 Flow Timers

Flow timers control the filling and clearing of formatted content from a presentation undergoing dynamic flow processing.

In the case of continuous time bases, the timeline of flow timers follows (is synchronized with) the time base that applies to the document instance as determined by the ttp:timeBase parameter; however, in the case of a discontinuous time base, the timeline of flow timers follows real (clock) time.

Note:

The semantics of flow timer initiated processing expressed below reflects the intent that clear and reflow operations or clear, reflow, and flow operations are performed simultaneously if the (logically, but not necesesarily temporally) prior operation would create sufficient space in the presentation region to accept the subsequent unit of formatted content.

When resetting a flow timer, the dynamic flow lock must first be acquired prior to changing the flow timer's value, and must be released immediately after making the change.

B.5.1 Fill Timer

The fill timer is used to pace the addition of formatted content to the presentation region undergoing dynamic flow ~~processing.~~ processing when the current value of the computed fill interval is a numeric value; however, if it is not a numeric value, then the fill timer remains inactive .

Note:

Although the fill timer is inactive when the value of the computed fill interval is non-numeric, the effects of fill timer expiration may nevertheless be simulated by certain conditions described elsewhere.

Each time the fill timer expires, the following ordered steps are performed:

acquire dynamic flow lock ;
if the current value of the computed clear interval is the token value break and the most temporally prior unfilled content in the flow buffer, i.e., the next available content available for a fill operation at the beginning of the flow buffer, is or starts with a retained line break, then perform steps (1) and (2) of the processing described in B.4.4 Combined Flow Operation ,i.e., perform the clear and reflow steps of the combined flow operation;
if (1) the current value of the computed fill interval is non-numeric or (2) the difference between the current value of the flow timers ' timeline and the last fill time is greater than or equal to the current value of the computed fill interval, then perform the following ordered sub-steps:
1. if (1) the presentation region is non-full and contains sufficient space to accept a fill unit and (2) the flow buffer contains sufficient content to compose a fill unit , then perform the processing described in B.4.1 Fill Operation ;
2. if the presentation region is non-empty, then perform the following ordered sub-steps:
  1. if the clear timer is not active, then reset the clear timer to the current value of the computed clear interval;
  2. if the fill timer is not active ~~and~~ , the flow buffer is ~~empty,~~ empty ,and the current value of the computed fill interval is a numeric value , then reset the fill timer to the current value of the computed fill interval.
otherwise ~~(the~~ ( the current value of the computed fill interval is numeric and the difference between the current value of the flow timers ' timeline and the last fill time is less than the current value of the computed fill interval), reset the fill timer to the difference between the current value of the computed fill interval and the current value of the flow timers ' timeline;
release dynamic flow lock .

B.5.2 Clear Timer

The clear timer is used to pace the removal of formatted content from the presentation region undergoing dynamic flow ~~processing.~~ processing when the current value of the computed clear interval is a numeric value; however, if it is not a numeric value, then the clear timer remains inactive .

Note:

Although the clear timer is inactive when the value of the computed clear interval is non-numeric, the effects of clear timer expiration may nevertheless be simulated by certain conditions described elsewhere.

Each time the clear timer expires, the following ordered steps are performed:

acquire dynamic flow lock ;
(1) the current value of the computed fill interval is non-numeric or (2) if the difference between the current value of the flow timers ' timeline and the last ~~fill~~ clear time is greater than or equal to the current value of the computed ~~fill~~ clear interval, then perform the following ordered sub-steps:
1. if the presentation region is non-empty and contains sufficient formatted content to compose a clear unit and either (1) the presentation region is so full as to prevent it from accepting another fill unit or (2) the flow buffer is empty, then perform the processing described in B.4.4 Combined Flow Operation ;
otherwise ~~(the~~ ( the current value of the computed clear interval is numeric and the difference between the current value of the flow timers ' timeline and the last clear time is less than the current value of the computed clear interval), reset the clear timer to the difference between the current value of the computed clear interval and the current value of the flow timers ' timeline;
release dynamic flow lock .

B.5.3 Timing Example

This section is non-normative.

An example of the timing of fill and clear timers is shown in Figure 2 – Timing Example .

Figure 2 – Timing Example

In this example, fill operations occur on word units, while clear operaations occur on line units. As a consequence, it takes more than one fill event to fill a new line capable of being cleared by a clear event. When insufficient layout space is available to add a new word to the after-most line area or to create a new line area, then fill operations are suspended. Similarly, when the region is not full (and unfilled content remains available), then clear operations are suspended.

This example also depicts the relationship between the fill style duration and the fill interval, as well as the relationship between the clear style duration and the clear interval. In no case can the fill interval be less than the fill style duration, nor can the clear interval be less than the clear style duration.

C Schemas

This appendix is normative.

This appendix specifies the following schemas for use with DFXP document instances:

Relax NG, Compact Syntax (RNC) Schema
XML Schema Definition (XSD) Schema

In any case where a schema specified by this appendix differs from the normative definitions of document type, element type, or attribute type as defined by the body of this specification, then the body of this specification takes precedence.

C.1 Relax NG Schema

This section specifies a Relax NG Compact Syntax (RNC) [RELAX NG] based schema for DFXP, also available in a ZIP Archive .

C.1.1 Driver

# .......................................................................
# TT-AF 1.0 Distribution Format Exchange Profile (DFXP) Schema ..........
# .......................................................................
# default namespace
default namespace tt = "http://www.w3.org/2006/10/ttaf1"
# generic tt modules
include "ttaf1-dfxp-datatypes.rnc"
include "ttaf1-dfxp-classes.rnc"
include "ttaf1-dfxp-core-attribs.rnc"
include "ttaf1-dfxp-parameter-attribs.rnc"
include "ttaf1-dfxp-metadata-attribs.rnc"
include "ttaf1-dfxp-styling-attribs.rnc"
include "ttaf1-dfxp-timing-attribs.rnc"
include "ttaf1-dfxp-parameter-items.rnc"
include "ttaf1-dfxp-parameters.rnc"
include "ttaf1-dfxp-metadata-items.rnc"
include "ttaf1-dfxp-metadata.rnc"
include "ttaf1-dfxp-styling.rnc"
include "ttaf1-dfxp-animation.rnc"
include "ttaf1-dfxp-layout.rnc"
include "ttaf1-dfxp-content.rnc"
include "ttaf1-dfxp-head.rnc"
include "ttaf1-dfxp-document.rnc"
start = TTAF.tt | TTAF.parameters.profile
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2 Modules

C.1.2.1 Animation Module

# .......................................................................
# TT-AF 1.0 DFXP Animation Module .......................................
# .......................................................................
# set - discrete animation
TTAF.set =
  element set {
    TTAF.set.attlist,
    TTAF.set.content
  }
TTAF.set.attlist &=
  TTAF.Core.attrib.class,
  TTAF.Timed.attrib.class,
  (TTAF.Styling.attrib.class |
   TTAF.Styling.ForeignExtension.attrib+ )
TTAF.set.content.extra = empty
TTAF.set.content =
  (TTAF.Metadata.class*,
   TTAF.set.content.extra*)
TTAF.Animation.extra = empty
TTAF.Animation.class |=
  TTAF.set |
  TTAF.Animation.extra
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.2 Classes Module

# .......................................................................
# TT-AF 1.0 DFXP Class Declarations Module ..............................
# .......................................................................
# attribute group classes
TTAF.Core.attrib.class = empty
TTAF.Metadata.attrib.class = empty
TTAF.Parameter.attrib.class = empty
TTAF.RegionBinding.attrib.class = empty
TTAF.StyleBinding.attrib.class = empty
TTAF.Styled.attrib.class = empty
TTAF.Styling.attrib.class = empty
TTAF.Timed.attrib.class = empty
TTAF.TimedContainer.attrib.class = empty
TTAF.TimingInterval.attrib.class = empty
# element group classes
TTAF.Animation.class = empty
TTAF.Block.class = empty
TTAF.BlockNoDiv.class = empty
TTAF.Inline.class = empty
TTAF.InlineNoSpan.class = empty
TTAF.MetadataNoAgent.class = empty
TTAF.Metadata.class = empty
TTAF.MetadataItems.class = empty
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.3 Content Module

# .......................................................................
# TT-AF 1.0 DFXP Content Module .........................................
# .......................................................................
# body - content body
TTAF.body =
  element body {
    TTAF.body.attlist,
    TTAF.body.content
  }
TTAF.body.attlist &=
  TTAF.Core.attrib.class,
  TTAF.Metadata.attrib.class,
  TTAF.RegionBinding.attrib.class,
  TTAF.Styled.attrib.class,
  TTAF.TimedContainer.attrib.class
TTAF.body.content.extra = empty
TTAF.body.content =
  (TTAF.Metadata.class*,
   TTAF.Animation.class*,
   (TTAF.Block.class | TTAF.body.content.extra)*)
# div - division
TTAF.div =
  element div {
    TTAF.div.attlist,
    TTAF.div.content
  }
TTAF.div.attlist &=
  TTAF.Core.attrib.class,
  TTAF.Metadata.attrib.class,
  TTAF.RegionBinding.attrib.class,
  TTAF.Styled.attrib.class,
  TTAF.TimedContainer.attrib.class
TTAF.div.content.extra = empty
TTAF.div.content =
  (TTAF.Metadata.class*,
   TTAF.Animation.class*,
   (TTAF.Block.class | TTAF.div.content.extra)*)
# p - paragraph
TTAF.p =
  element p {
    TTAF.p.attlist,
    TTAF.p.content
  }
TTAF.p.attlist &=
  TTAF.Core.attrib.class,
  TTAF.Metadata.attrib.class,
  TTAF.RegionBinding.attrib.class,
  TTAF.Styled.attrib.class,
  TTAF.TimedContainer.attrib.class
TTAF.p.content.extra = empty
TTAF.p.content =
  (TTAF.Metadata.class*,
   TTAF.Animation.class*,
   (TTAF.Inline.class |
    TTAF.p.content.extra)*)
# span - intra-paragraph inline span
TTAF.span =
  element span {
    TTAF.span.attlist,
    TTAF.span.content
  }
TTAF.span.attlist &=
  TTAF.Core.attrib.class,
  TTAF.Metadata.attrib.class,
  TTAF.RegionBinding.attrib.class,
  TTAF.Styled.attrib.class,
  TTAF.TimedContainer.attrib.class
TTAF.span.content.extra = empty
TTAF.span.content =
  (TTAF.Metadata.class*,
   TTAF.Animation.class*,
   (TTAF.Inline.class |
    TTAF.span.content.extra)*)
# br - manual line break
TTAF.br =
  element br {
    TTAF.br.attlist,
    TTAF.br.content
  }
TTAF.br.attlist &=
  TTAF.Core.attrib.class,
  TTAF.Metadata.attrib.class,
  TTAF.Styled.attrib.class
TTAF.br.content.extra = empty
TTAF.br.content =
  (TTAF.Metadata.class*,
   TTAF.Animation.class*,
   TTAF.br.content.extra*)
# Block.class
TTAF.Block.extra = empty
TTAF.BlockNoDiv.class |=
  TTAF.p | TTAF.Block.extra
TTAF.Block.class |=
  TTAF.div | TTAF.BlockNoDiv.class
# Inline.class
TTAF.Inline.extra = empty
TTAF.InlineNoSpan.class |=
  text | TTAF.br | TTAF.Inline.extra
TTAF.Inline.class |=
  TTAF.span | TTAF.InlineNoSpan.class
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.4 Core Attributes Module

# .......................................................................
# TT-AF 1.0 DFXP Core Attributes Module .................................
# .......................................................................
TTAF.id.attrib
  = attribute xml:id { xsd:ID }?
TTAF.lang.attrib
  = attribute xml:lang { TTAF.LanguageCode.datatype }?
TTAF.lang.required.attrib
  = attribute xml:lang { TTAF.LanguageCode.datatype }
TTAF.space.attrib
  = attribute xml:space { TTAF.XMLSpace.datatype }?
TTAF.Core.extra.attrib
  = empty
TTAF.Core.attrib.class &=
  TTAF.id.attrib,
  TTAF.lang.attrib,
  TTAF.space.attrib,
  TTAF.Core.extra.attrib
TTAF.Core.required.attrib.class &=
  TTAF.id.attrib,
  TTAF.lang.required.attrib,
  TTAF.space.attrib,
  TTAF.Core.extra.attrib
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.5 Data Types Module

# .......................................................................
# TT-AF 1.0 DFXP Datatypes Module .......................................
# .......................................................................
TTAF.Alpha.datatype =
  xsd:float { minInclusive = "0" maxInclusive = "1" }
TTAF.Agent.datatype =
  xsd:IDREFS
TTAF.CellResolution.datatype =
  string
TTAF.ClockMode.datatype =
  "local" |
  "gps" |
  "utc"
TTAF.Color.datatype =
  string
TTAF.Direction.datatype =
  "ltr" |
  "rtl"
TTAF.Display.datatype =
  "auto" |
  "none"
TTAF.DisplayAlign.datatype =
  "before" |
  "center" |
  "after"
TTAF.DropMode.datatype =
  "dropNTSC" |
  "dropPAL" |
  "nonDrop"

TTAF.DynamicFlow.datatype =
  string
TTAF.ExtensionDesignator.datatype =
  TTAF.URI.datatype
TTAF.ExtensionValue.datatype =
 "optional" |
 "required" |
 "use"
TTAF.Extent.datatype =
  string
TTAF.FeatureDesignator.datatype =
  TTAF.URI.datatype
TTAF.FeatureValue.datatype =
 "optional" |
 "required" |
 "use"
TTAF.FontFamily.datatype =
  string
TTAF.FontSize.datatype =
  string
TTAF.FontStyle.datatype =
  "normal" |
  "italic" |
  "oblique" |
  "reverseOblique"
TTAF.FontWeight.datatype =
  "normal" |
  "bold"
TTAF.FrameRate.datatype =
  xsd:nonNegativeInteger
TTAF.FrameRateMultiplier.datatype =
  xsd:string { pattern = "\p{Nd}+(\s*:\s*\p{Nd}+)?" }
TTAF.LanguageCode.datatype =
  xsd:NMTOKEN
TTAF.LineHeight.datatype =
  string
TTAF.MarkerMode.datatype =
  "continuous" |
  "discontinuous"
TTAF.MetadataAgentType.datatype =
  "person" |
  "character" |
  "group" |
  "organization" |
  "other"
TTAF.MetadataNameType.datatype =
  "full" |
  "family" |
  "given" |
  "alias" |
  "other"
TTAF.MetadataRoleBaseType.datatype =
  "action" |
  "caption" |
  "description" |
  "dialog" |
  "expletive" |
  "kinesic" |
  "lyrics" |
  "music" |
  "narration" |
  "quality" |
  "sound" |
  "source" |
  "suppressed" |
  "reproduction" |
  "thought" |
  "title" |
  "transcription"
TTAF.Opacity.datatype =
  string
TTAF.Origin.datatype =
  string
TTAF.Overflow.datatype =
  "visible" |
  "hidden" |
  "dynamic"
TTAF.Padding.datatype =
  string
TTAF.PixelAspectRatio.datatype =
  xsd:string { pattern = "\p{Nd}+\s*:\s*\p{Nd}+" }
TTAF.Profile.datatype =
  TTAF.URI.datatype
TTAF.Role.datatype =
  xsd:NMTOKENS
TTAF.ShowBackground.datatype =
  "always" |
  "whenActive"
TTAF.SMPTEMode.datatype =
  "dropNTSC" |
  "dropPAL" |
  "nonDrop"

TTAF.SubFrameRate.datatype =
  xsd:positiveInteger
TTAF.TextAlign.datatype =
  "left" |
  "center" |
  "right" |
  "start" |
  "end"
TTAF.TextDecoration.datatype =
  "none" |
  "underline" |
  "noUnderline" |
  "overline" |
  "noOverline" |
  "lineThrough" |
  "noLineThrough"
TTAF.TextOutline.datatype =
  string
TTAF.TickRate.datatype =
  xsd:positiveInteger
TTAF.TimeBase.datatype =
  "media" |
  "smpte" |
  "clock"
TTAF.TimeContainer.datatype =
  "par" |
  "seq"
TTAF.TimeCoordinate.datatype =
  string
TTAF.TimeDuration.datatype =
  string
TTAF.URI.datatype =
  xsd:anyURI
TTAF.UnicodeBidi.datatype =
  "normal" |
  "embed" |
  "bidiOverride"
TTAF.Visibility.datatype =
  "hidden" |
  "visible"
TTAF.WrapOption.datatype =
  "wrap" |
  "noWrap"
TTAF.WritingMode.datatype =
  "lrtb" |
  "rltb" |
  "tbrl" |
  "tblr" |
  "lr" |
  "rl" |
  "tb"
TTAF.XMLSpace.datatype =
  "default" |
  "preserve"
TTAF.ZIndex.datatype =
  string
  
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.6 Document Module

# .......................................................................
# TT-AF 1.0 DFXP Document Module ........................................
# .......................................................................
## tt - generic top-level document element type
TTAF.tt =
  element tt {
    TTAF.tt.attlist,
    TTAF.tt.content
  }
TTAF.tt.attlist &=
  TTAF.Core.required.attrib.class,
  TTAF.Parameter.attrib.class
TTAF.tt.content =
  (TTAF.head?, TTAF.body?)
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.7 Header Module

# .......................................................................
# TT-AF 1.0 DFXP Header Module ..........................................
# .......................................................................
# head - generic header
TTAF.head =
  element head {
    TTAF.head.attlist,
    TTAF.head.content
  }
TTAF.head.attlist &=
  TTAF.Core.attrib.class
TTAF.head.content.extra = empty
TTAF.head.content =
  (TTAF.Metadata.class*,
   TTAF.Parameters.class*,
   TTAF.styling?,
   TTAF.layout?,
   TTAF.head.content.extra*)
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.8 Layout Module

# .......................................................................
# TT-AF 1.0 DFXP Layout Module ..........................................
# .......................................................................
# region reference attribute; must reference /head/layout/region
TTAF.region.attrib
  = attribute region { xsd:IDREF }?
# region binding attribute class
TTAF.RegionBinding.attrib.class &=
  TTAF.region.attrib
# layout - generic layout container
TTAF.layout =
  element layout {
    TTAF.layout.attlist,
    TTAF.layout.content
  }
TTAF.layout.attlist &=
  TTAF.Core.attrib.class
TTAF.layout.content.extra = empty
TTAF.layout.content =
  (TTAF.Metadata.class*,
   TTAF.layout.region*,
   TTAF.layout.content.extra*)
# region - region declaration
TTAF.layout.region =
  element region {
    TTAF.layout.region.attlist,
    TTAF.layout.region.content
  }
TTAF.layout.region.attlist &=
  TTAF.Core.attrib.class,
  TTAF.TimedContainer.attrib.class,
  TTAF.style.attrib,
  (TTAF.Styling.attrib.class |
   TTAF.Styling.ForeignExtension.attrib+ )
TTAF.layout.region.content.extra = empty
TTAF.layout.region.content =
  (TTAF.Metadata.class*,
   TTAF.Animation.class*,
   TTAF.styling.style*,
   TTAF.layout.region.content.extra*)
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.9 Metadata Module

# .......................................................................
# TT-AF 1.0 DFXP Metadata Module ........................................
# .......................................................................
# namespace prefix bindings
namespace tt = "http://www.w3.org/2006/10/ttaf1"
namespace ttm = "http://www.w3.org/2006/10/ttaf1#metadata"

namespace local = ""
# meta - generic metadata
TTAF.metadata =
  element metadata {
    TTAF.metadata.attlist,
    TTAF.metadata.content
  }
TTAF.metadata.attlist &=
  TTAF.Core.attrib.class
TTAF.External.class =
  element * - tt:* {
    ( attribute * - ( xml:* | local:* ) { text }

  element * - ( tt:* | ttm:* ) {
    ( attribute * - ( xml:id ) { text }

      | text
      | TTAF.External.class
    )*
  }
TTAF.metadata.content.extra = empty
TTAF.metadata.content =
  (TTAF.External.class |

  (TTAF.MetadataItems.class |
   TTAF.External.class |

   TTAF.metadata.content.extra)*
TTAF.MetadataNoAgent.class |=

TTAF.Metadata.class |=

  TTAF.MetadataItems.class |
  TTAF.metadata
TTAF.Metadata.class |=
  TTAF.MetadataNoAgent.class |
  TTAF.meta.agent

# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.10 Metadata Items Module

# .......................................................................
# TT-AF 1.0 DFXP Metadata Items Module ......................................
# .......................................................................
namespace ttm = "http://www.w3.org/2006/10/ttaf1#metadata"
namespace ttmx = "http://www.w3.org/2006/10/ttaf1#metadata-extension"

## actor - specifies actor
TTAF.meta.actor =
  element ttm:actor {
    TTAF.meta.actor.attlist,
    TTAF.meta.actor.content
  }
TTAF.meta.actor.attlist &=
  TTAF.Core.attrib.class,
  attribute agent { xsd:IDREF }
TTAF.meta.actor.content.extra = empty
TTAF.meta.actor.content = empty
## agent - specifies agent
TTAF.meta.agent =
  element ttm:agent {
    TTAF.meta.agent.attlist,
    TTAF.meta.agent.content
  }
TTAF.meta.agent.attlist &=
  TTAF.Core.attrib.class,
  attribute type { TTAF.MetadataAgentType.datatype }
TTAF.meta.agent.content.extra = empty
TTAF.meta.agent.content =
  (TTAF.meta.name*,
   TTAF.meta.actor?,
   TTAF.meta.agent.content.extra*)
## copyright - specifies copyright statement
TTAF.meta.copyright =
  element ttm:copyright {
    TTAF.meta.copyright.attlist,
    TTAF.meta.copyright.content
  }
TTAF.meta.copyright.attlist &=
  TTAF.Core.attrib.class
TTAF.meta.copyright.content.extra = empty
TTAF.meta.copyright.content = text
## desc - specifies description
TTAF.meta.desc =
  element ttm:desc {
    TTAF.meta.desc.attlist,
    TTAF.meta.desc.content
  }
TTAF.meta.desc.attlist &=
  TTAF.Core.attrib.class
TTAF.meta.desc.content.extra = empty
TTAF.meta.desc.content = text
## name - specifies name
TTAF.meta.name =
  element ttm:name {
    TTAF.meta.name.attlist,
    TTAF.meta.name.content
  }
TTAF.meta.name.attlist &=
  TTAF.Core.attrib.class,
  attribute type { TTAF.MetadataNameType.datatype }
TTAF.meta.name.content.extra = empty
TTAF.meta.name.content = text
## title - describes title
TTAF.meta.title =
  element ttm:title {
    TTAF.meta.title.attlist,
    TTAF.meta.title.content
  }
TTAF.meta.title.attlist &=
  TTAF.Core.attrib.class
TTAF.meta.title.content.extra = empty
TTAF.meta.title.content = text
## MetadataItems.class
TTAF.MetadataItems.extra = empty
TTAF.MetadataItems.class |=
  TTAF.meta.title |
  TTAF.meta.desc |

  TTAF.meta.agent |

  TTAF.meta.copyright |
  TTAF.meta.desc |
  TTAF.meta.title |

  TTAF.MetadataItems.extra
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.11 Metadata Attributes Module

# .......................................................................
# TT-AF 1.0 DFXP Metadata Attributes Module ..............................
# .......................................................................
namespace tt = "http://www.w3.org/2006/10/ttaf1"
namespace ttm = "http://www.w3.org/2006/10/ttaf1#metadata"
namespace ttmx = "http://www.w3.org/2006/10/ttaf1#metadata-extension"

namespace local = ""
# Standard Metadata Attributes
TTAF.agent.attrib
  = attribute ttm:agent { TTAF.Agent.datatype }?
TTAF.role.attrib
  = attribute ttm:role { TTAF.Role.datatype }?
# Extension Metadata Attributes
TTAF.Metadata.Extension.attrib =
  attribute ttmx:* { text }

# Metadata Attribute Class
TTAF.Metadata.attrib.class &=
  TTAF.agent.attrib,
  TTAF.role.attrib
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.12 Parameters Module

# .......................................................................
# TT-AF 1.0 DFXP Parameters Module ......................................
# .......................................................................
TTAF.Parameters.class |=
  TTAF.ParameterItems.class
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.13 Parameter Items Module

# .......................................................................
# TT-AF 1.0 DFXP Parameter Items Module .................................
# .......................................................................
namespace ttp = "http://www.w3.org/2006/10/ttaf1#parameter"
# profile - profile definition or use declaration
TTAF.parameters.profile =
  element ttp:profile {
    TTAF.parameters.profile.attlist,
    TTAF.parameters.profile.content
  }
TTAF.parameters.profile.attlist &=
  TTAF.id.attrib,
  attribute use { TTAF.Profile.datatype }?
TTAF.parameters.profile.content.extra = empty
TTAF.parameters.profile.content =
  (TTAF.Metadata.class*,
   TTAF.parameters.features*,
   TTAF.parameters.extensions*,
   TTAF.parameters.profile.content.extra*)
# features - container for feature elements
TTAF.parameters.features =
  element ttp:features {
    TTAF.parameters.features.attlist,
    TTAF.parameters.features.content
  }
TTAF.parameters.features.attlist &=
  TTAF.id.attrib,
  attribute xml:base { TTAF.URI.datatype }?
TTAF.parameters.features.content.extra = empty
TTAF.parameters.features.content =
  (TTAF.Metadata.class*,
   TTAF.parameters.feature*,
   TTAF.parameters.features.content.extra*)
# feature - feature requirements declaration
TTAF.parameters.feature =
  element ttp:feature {
    TTAF.parameters.feature.attlist,
    TTAF.parameters.feature.content
  }
TTAF.parameters.feature.attlist =
  TTAF.id.attrib,
  attribute value { TTAF.FeatureValue.datatype }?
TTAF.parameters.feature.content =
  TTAF.FeatureDesignator.datatype
# extensions - container for extension elements
TTAF.parameters.extensions =
  element ttp:extensions {
    TTAF.parameters.extensions.attlist,
    TTAF.parameters.extensions.content
  }
TTAF.parameters.extensions.attlist &=
  TTAF.id.attrib,
  attribute xml:base { TTAF.URI.datatype }?
TTAF.parameters.extensions.content.extra = empty
TTAF.parameters.extensions.content =
  (TTAF.Metadata.class*,
   TTAF.parameters.extension*,
   TTAF.parameters.extensions.content.extra*)
# extension - extension requirements declaration
TTAF.parameters.extension =
  element ttp:extension {
    TTAF.parameters.extension.attlist,
    TTAF.parameters.extension.content
  }
TTAF.parameters.extension.attlist =
  TTAF.id.attrib,
  attribute value { TTAF.ExtensionValue.datatype }?
TTAF.parameters.extension.content =
  TTAF.ExtensionDesignator.datatype
## ParameterItems.class
TTAF.ParameterItems.extra = empty
TTAF.ParameterItems.class |=
  TTAF.parameters.profile |
  TTAF.ParameterItems.extra
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.14 Parameter Attributes Module

# .......................................................................
# TT-AF 1.0 DFXP Parameter Attributes Module ............................
# .......................................................................
namespace ttp = "http://www.w3.org/2006/10/ttaf1#parameter"
# Standard Metadata Attributes
TTAF.cellResolution.attrib
  = attribute ttp:cellResolution { TTAF.CellResolution.datatype }?
TTAF.clockMode.attrib
  = attribute ttp:clockMode { TTAF.ClockMode.datatype }?
TTAF.dropMode.attrib
  = attribute ttp:dropMode { TTAF.DropMode.datatype }?

TTAF.frameRate.attrib
  = attribute ttp:frameRate { TTAF.FrameRate.datatype }?
TTAF.frameRateMultiplier.attrib
  = attribute ttp:frameRateMultiplier { TTAF.FrameRateMultiplier.datatype }?
TTAF.markerMode.attrib
  = attribute ttp:markerMode { TTAF.MarkerMode.datatype }?
TTAF.profile.attrib
  = attribute ttp:profile { TTAF.Profile.datatype }?
TTAF.pixelAspectRatio.attrib
  = attribute ttp:pixelAspectRatio { TTAF.PixelAspectRatio.datatype }?
TTAF.smpteMode.attrib
  = attribute ttp:smpteMode { TTAF.SMPTEMode.datatype }?

TTAF.subFrameRate.attrib
  = attribute ttp:subFrameRate { TTAF.SubFrameRate.datatype }?
TTAF.tickRate.attrib
  = attribute ttp:tickRate { TTAF.TickRate.datatype }?
TTAF.timeBase.attrib
  = attribute ttp:timeBase { TTAF.TimeBase.datatype }?
# Parameter Attribute Class
TTAF.Parameter.attrib.class &=
  TTAF.cellResolution.attrib,
  TTAF.clockMode.attrib,
  TTAF.dropMode.attrib,

  TTAF.frameRate.attrib,
  TTAF.frameRateMultiplier.attrib,
  TTAF.markerMode.attrib,
  TTAF.pixelAspectRatio.attrib,
  TTAF.profile.attrib,
  TTAF.smpteMode.attrib,

  TTAF.subFrameRate.attrib,
  TTAF.tickRate.attrib,
  TTAF.timeBase.attrib
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.15 Styling Attributes Module

# .......................................................................
# TT-AF 1.0 DFXP Styling Attributes Module ..............................
# .......................................................................
namespace tt = "http://www.w3.org/2006/10/ttaf1"
namespace tts = "http://www.w3.org/2006/10/ttaf1#style"
namespace ttsx = "http://www.w3.org/2006/10/ttaf1#style-extension"

namespace tts = "http://www.w3.org/2006/10/ttaf1#styling"

namespace local = ""
# Standard Style Attributes
TTAF.backgroundColor.attrib
  = attribute tts:backgroundColor { TTAF.Color.datatype }?
TTAF.color.attrib
  = attribute tts:color { TTAF.Color.datatype }?
TTAF.direction.attrib
  = attribute tts:direction { TTAF.Direction.datatype }?
TTAF.display.attrib
  = attribute tts:display { TTAF.Display.datatype }?
TTAF.displayAlign.attrib
  = attribute tts:displayAlign { TTAF.DisplayAlign.datatype }?
TTAF.dynamicFlow.attrib
  = attribute tts:dynamicFlow { TTAF.DynamicFlow.datatype }?
TTAF.extent.attrib
  = attribute tts:extent { TTAF.Extent.datatype }?
TTAF.fontFamily.attrib
  = attribute tts:fontFamily { TTAF.FontFamily.datatype }?
TTAF.fontSize.attrib
  = attribute tts:fontSize { TTAF.FontSize.datatype }?
TTAF.fontStyle.attrib
  = attribute tts:fontStyle { TTAF.FontStyle.datatype }?
TTAF.fontWeight.attrib
  = attribute tts:fontWeight { TTAF.FontWeight.datatype }?
TTAF.lineHeight.attrib
  = attribute tts:lineHeight { TTAF.LineHeight.datatype }?
TTAF.opacity.attrib
  = attribute tts:opacity { TTAF.Opacity.datatype }?
TTAF.origin.attrib
  = attribute tts:origin { TTAF.Origin.datatype }?
TTAF.overflow.attrib
  = attribute tts:overflow { TTAF.Overflow.datatype }?
TTAF.padding.attrib
  = attribute tts:padding { TTAF.Padding.datatype }?
TTAF.showBackground.attrib
  = attribute tts:showBackground { TTAF.ShowBackground.datatype }?
TTAF.textAlign.attrib
  = attribute tts:textAlign { TTAF.TextAlign.datatype }?
TTAF.textDecoration.attrib
  = attribute tts:textDecoration { TTAF.TextDecoration.datatype }?
TTAF.textOutline.attrib
  = attribute tts:textOutline { TTAF.TextOutline.datatype }?
TTAF.unicodeBidi.attrib
  = attribute tts:unicodeBidi { TTAF.UnicodeBidi.datatype }?
TTAF.visibility.attrib
  = attribute tts:visibility { TTAF.Visibility.datatype }?
TTAF.wrapOption.attrib
  = attribute tts:wrapOption { TTAF.WrapOption.datatype }?
TTAF.writingMode.attrib
  = attribute tts:writingMode { TTAF.WritingMode.datatype }?
TTAF.zIndex.attrib
  = attribute tts:zIndex { TTAF.ZIndex.datatype }?
# Extension Style Attributes
TTAF.Styling.Extension.attrib =
  attribute ttsx:* { text }

TTAF.Styling.ForeignExtension.attrib =
  attribute * - ( tt:* | tts:* | ttsx:* | xml:* | local:* ) { text }

  attribute * - ( tt:* | tts:* | xml:* | local:* ) { text }

# Styling Attribute Class
TTAF.Styling.attrib.class &=
  TTAF.backgroundColor.attrib,
  TTAF.color.attrib,
  TTAF.direction.attrib,

  TTAF.display.attrib,
  TTAF.displayAlign.attrib,
  TTAF.dynamicFlow.attrib,
  TTAF.extent.attrib,
  TTAF.fontFamily.attrib,
  TTAF.fontSize.attrib,
  TTAF.fontStyle.attrib,
  TTAF.fontWeight.attrib,
  TTAF.lineHeight.attrib,
  TTAF.opacity.attrib,
  TTAF.origin.attrib,
  TTAF.overflow.attrib,
  TTAF.padding.attrib,
  TTAF.showBackground.attrib,
  TTAF.textAlign.attrib,
  TTAF.textDecoration.attrib,
  TTAF.textOutline.attrib,
  TTAF.unicodeBidi.attrib,

  TTAF.visibility.attrib,
  TTAF.wrapOption.attrib,
  TTAF.writingMode.attrib,
  TTAF.zIndex.attrib
# Style Binding Attribute Class
TTAF.StyleBinding.attrib.class &=
  TTAF.style.attrib
# Styled Content Attribute Class
TTAF.Styled.extra.attrib = empty
TTAF.Styled.attrib.class &=
  TTAF.Styling.attrib.class,
  TTAF.StyleBinding.attrib.class,
  TTAF.Styled.extra.attrib
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.16 Styling Module

# .......................................................................
# TT-AF 1.0 DFXP Styling Module .........................................
# .......................................................................
# style reference attribute; must reference /tt/head/styling/style
TTAF.style.attrib
  = attribute style { xsd:IDREFS }?
# styling - generic styling container
TTAF.styling =
  element styling {
    TTAF.styling.attlist,
    TTAF.styling.content
  }
TTAF.styling.attlist &=
  TTAF.Core.attrib.class
TTAF.styling.content.extra = empty
TTAF.styling.content =
  (TTAF.Metadata.class*,
   TTAF.styling.defs.class*,
   TTAF.styling.content.extra*)
# style - style declaration
TTAF.styling.style =
  element style {
    TTAF.styling.style.attlist,
    TTAF.styling.style.content
  }
TTAF.styling.style.attlist =
  TTAF.Core.attrib.class,
  TTAF.style.attrib,
  (TTAF.Styling.attrib.class |
   TTAF.Styling.ForeignExtension.attrib+ )
TTAF.styling.style.content.extra = empty
TTAF.styling.style.content =
  (TTAF.Metadata.class*,
   (TTAF.styling.style.content.extra)*)
# style definitions class
TTAF.styling.defs.extra = empty
TTAF.styling.defs.class = 
  TTAF.styling.style
  | TTAF.styling.defs.extra
# .......................................................................
# .......................................................................
# .......................................................................

C.1.2.17 Timing Attributes Module

# .......................................................................
# TT-AF 1.0 DFXP Timing Attributes Module ...............................
# .......................................................................
# Timing Attributes
TTAF.timing.begin.attrib
  = attribute begin { TTAF.TimeCoordinate.datatype }?
TTAF.timing.dur.attrib
  = attribute dur { TTAF.TimeDuration.datatype }?
TTAF.timing.end.attrib
  = attribute end { TTAF.TimeCoordinate.datatype }?
TTAF.timing.timeContainer.attrib
  = attribute timeContainer { TTAF.TimeContainer.datatype }?
# Timing Interval Attribute class
TTAF.TimingInterval.extra.attrib = empty
TTAF.TimingInterval.attrib.class &=
  TTAF.timing.begin.attrib,
  TTAF.timing.dur.attrib,
  TTAF.timing.end.attrib,
  TTAF.TimingInterval.extra.attrib
# Timing Container Attribute class
TTAF.TimingContainer.extra.attrib = empty
TTAF.TimingContainer.attrib.class &=
  TTAF.timing.timeContainer.attrib,
  TTAF.TimingContainer.extra.attrib
# Timed Content Attribute Class
TTAF.Timed.extra.attrib = empty
TTAF.Timed.attrib.class &=
  TTAF.TimingInterval.attrib.class,
  TTAF.Timed.extra.attrib
# Timed Content Container Attribute Class
TTAF.TimedContainer.extra.attrib = empty
TTAF.TimedContainer.attrib.class &=
  TTAF.Timed.attrib.class,
  TTAF.TimingContainer.attrib.class,
  TTAF.TimedContainer.extra.attrib
# .......................................................................
# .......................................................................
# .......................................................................

C.2 XML Schema Definition (XSD) Schema

This section specifies a W3C XML Schema Definition (XSD) [XML Schema Part 1] based schema for DFXP, also available in a ZIP Archive .

C.2.1 Driver

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1">
  <xs:include schemaLocation="ttaf1-dfxp-document.xsd"/>
</xs:schema>

C.2.2 Modules

C.2.2.1 Animation Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-timing-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-metadata.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#styling"
    schemaLocation="ttaf1-dfxp-styling-attribs.xsd"/>
  <xs:attributeGroup name="set.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class" />
    <xs:attributeGroup ref="tt:Timed.attrib.class" />
    <xs:attributeGroup ref="tts:Styling.attrib.class" />
  </xs:attributeGroup>
  <xs:complexType name="set.eltype">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:set.attlist"/>
  </xs:complexType>
  <xs:element name="set" type="tt:set.eltype"/>
  <xs:group name="Animation.class">
    <xs:choice>
      <xs:element ref="tt:set"/>
    </xs:choice>
  </xs:group>
</xs:schema>

C.2.2.2 Content Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-timing-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-metadata.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-animation.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-layout.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-styling.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#metadata"
    schemaLocation="ttaf1-dfxp-metadata-attribs.xsd"/>
  <xs:attributeGroup name="body.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
    <xs:attributeGroup ref="tt:TimedContainer.attrib.class"/>
    <xs:attributeGroup ref="tt:RegionBinding.attrib.class"/>
    <xs:attributeGroup ref="tt:Styled.attrib.class"/>
    <xs:attributeGroup ref="ttm:Metadata.attrib.class"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="div.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
    <xs:attributeGroup ref="tt:TimedContainer.attrib.class"/>
    <xs:attributeGroup ref="tt:RegionBinding.attrib.class"/>
    <xs:attributeGroup ref="tt:Styled.attrib.class"/>
    <xs:attributeGroup ref="ttm:Metadata.attrib.class"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="p.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
    <xs:attributeGroup ref="tt:TimedContainer.attrib.class"/>
    <xs:attributeGroup ref="tt:RegionBinding.attrib.class"/>
    <xs:attributeGroup ref="tt:Styled.attrib.class"/>
    <xs:attributeGroup ref="ttm:Metadata.attrib.class"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="span.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
    <xs:attributeGroup ref="tt:TimedContainer.attrib.class"/>
    <xs:attributeGroup ref="tt:RegionBinding.attrib.class"/>
    <xs:attributeGroup ref="tt:Styled.attrib.class"/>
    <xs:attributeGroup ref="ttm:Metadata.attrib.class"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="br.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
    <xs:attributeGroup ref="tt:Styled.attrib.class"/>
    <xs:attributeGroup ref="ttm:Metadata.attrib.class"/>
  </xs:attributeGroup>
  <xs:complexType name="body.eltype">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="tt:div" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:body.attlist"/>
  </xs:complexType>
  <xs:complexType name="div.eltype">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:group ref="tt:Block.class" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:div.attlist"/>
  </xs:complexType>
  <xs:complexType name="p.eltype" mixed="true">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:group ref="tt:Inline.class" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:p.attlist"/>
  </xs:complexType>
  <xs:complexType name="span.eltype" mixed="true">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:group ref="tt:Inline.class" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:span.attlist"/>
  </xs:complexType>
  <xs:complexType name="br.eltype">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:br.attlist"/>
  </xs:complexType>
  <xs:element name="body" type="tt:body.eltype"/>
  <xs:element name="div" type="tt:div.eltype"/>
  <xs:element name="p" type="tt:p.eltype"/>
  <xs:element name="span" type="tt:span.eltype"/>
  <xs:element name="br" type="tt:br.eltype"/>
  <xs:group name="BlockNoDiv.class">
    <xs:choice>
      <xs:element ref="tt:p"/>
    </xs:choice>
  </xs:group>
  <xs:group name="Block.class">
    <xs:choice>
      <xs:group ref="tt:BlockNoDiv.class"/>
      <xs:element ref="tt:div"/>
    </xs:choice>
  </xs:group>
  <xs:group name="InlineNoSpan.class">
    <xs:choice>
      <xs:element ref="tt:br"/>
    </xs:choice>
  </xs:group>
  <xs:group name="Inline.class">
    <xs:choice>
      <xs:group ref="tt:InlineNoSpan.class"/>
      <xs:element ref="tt:span"/>
    </xs:choice>
  </xs:group>
</xs:schema>

C.2.2.3 Core Attributes Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:xml="http://www.w3.org/XML/1998/namespace">
  <xs:import namespace="http://www.w3.org/XML/1998/namespace"
    schemaLocation="xml.xsd"/>
  <xs:attributeGroup name="Core.ID.attrib.class">
    <xs:attribute ref="xml:id"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="Core.attrib.class">
    <xs:attributeGroup ref="tt:Core.ID.attrib.class"/>
    <xs:attribute ref="xml:lang"/>
    <xs:attribute ref="xml:space"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="Core.required.attrib.class">
    <xs:attributeGroup ref="tt:Core.ID.attrib.class"/>
    <xs:attribute ref="xml:lang" use="required"/>
    <xs:attribute ref="xml:space"/>
  </xs:attributeGroup>
</xs:schema>

C.2.2.4 Data Types Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1#datatype"
        xml:lang="en" xmlns:xs="http://www.w3.org/2001/XMLSchema"
        xmlns:ttd="http://www.w3.org/2006/10/ttaf1#datatype">
  <xs:simpleType name="alpha">
    <xs:restriction base="xs:float">
      <xs:minInclusive value="0"/>
      <xs:maxInclusive value="1"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="agent">
    <xs:restriction base="xs:IDREFS"/>
  </xs:simpleType>
  <xs:simpleType name="cellResolution">
    <xs:annotation>
      <xs:documentation>positiveInteger positiveInteger</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="clockMode">
    <xs:restriction base="xs:token">
      <xs:enumeration value="local"/>
      <xs:enumeration value="gps"/>
      <xs:enumeration value="utc"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="color">
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="direction">
    <xs:restriction base="xs:token">
      <xs:enumeration value="ltr"/>
      <xs:enumeration value="rtl"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="display">
    <xs:restriction base="xs:token">
      <xs:enumeration value="auto"/>
      <xs:enumeration value="none"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="displayAlign">
    <xs:restriction base="xs:token">
      <xs:enumeration value="before"/>
      <xs:enumeration value="center"/>
      <xs:enumeration value="after"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="dropMode">
    <xs:restriction base="xs:token">
      <xs:enumeration value="dropNTSC"/>
      <xs:enumeration value="dropPAL"/>
      <xs:enumeration value="nonDrop"/>
    </xs:restriction>
  </xs:simpleType>

  <xs:simpleType name="dynamicFlow">
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="extensionDesignator">
    <xs:restriction base="xs:anyURI"/>
  </xs:simpleType>
  <xs:simpleType name="extensionValue">
    <xs:restriction base="xs:token">
      <xs:enumeration value="optional"/>
      <xs:enumeration value="required"/>
      <xs:enumeration value="use"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="extent">
    <xs:annotation>
      <xs:documentation>auto | length length</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="featureDesignator">
    <xs:restriction base="xs:anyURI"/>
  </xs:simpleType>
  <xs:simpleType name="featureValue">
    <xs:restriction base="xs:token">
      <xs:enumeration value="optional"/>
      <xs:enumeration value="required"/>
      <xs:enumeration value="use"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="fontFamily">
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="fontSize">
    <xs:annotation>
      <xs:documentation>length | length length</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="fontStyle">
    <xs:restriction base="xs:token">
      <xs:enumeration value="normal"/>
      <xs:enumeration value="italic"/>
      <xs:enumeration value="oblique"/>
      <xs:enumeration value="reverseOblique"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="fontWeight">
    <xs:restriction base="xs:token">
      <xs:enumeration value="normal"/>
      <xs:enumeration value="bold"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="frameRate">
    <xs:restriction base="xs:nonNegativeInteger"/>
  </xs:simpleType>
  <xs:simpleType name="frameRateMultiplier">
    <xs:annotation>
      <xs:documentation>positiveInteger:positiveInteger</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string">
      <xs:pattern value="\p{Nd}+(\s*:\s*\p{Nd}+)?"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="lineHeight">
    <xs:annotation>
      <xs:documentation>normal | length</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="markerMode">
    <xs:restriction base="xs:token">
      <xs:enumeration value="continuous"/>
      <xs:enumeration value="discontinuous"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="metadataAgentType">
    <xs:restriction base="xs:token">
      <xs:enumeration value="person"/>
      <xs:enumeration value="character"/>
      <xs:enumeration value="group"/>
      <xs:enumeration value="organization"/>
      <xs:enumeration value="other"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="metadataNameType">
    <xs:restriction base="xs:token">
      <xs:enumeration value="full"/>
      <xs:enumeration value="family"/>
      <xs:enumeration value="given"/>
      <xs:enumeration value="alias"/>
      <xs:enumeration value="other"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="metadataRoleBaseType">
    <xs:annotation>
      <xs:documentation>orphan simpleType retained in hope it can be used for role</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:token">
      <xs:enumeration value="action"/>
      <xs:enumeration value="caption"/>
      <xs:enumeration value="description"/>
      <xs:enumeration value="dialog"/>
      <xs:enumeration value="expletive"/>
      <xs:enumeration value="kinesic"/>
      <xs:enumeration value="lyrics"/>
      <xs:enumeration value="music"/>
      <xs:enumeration value="narration"/>
      <xs:enumeration value="quality"/>
      <xs:enumeration value="sound"/>
      <xs:enumeration value="source"/>
      <xs:enumeration value="suppressed"/>
      <xs:enumeration value="reproduction"/>
      <xs:enumeration value="thought"/>
      <xs:enumeration value="title"/>
      <xs:enumeration value="transcription"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="opacity">
    <xs:annotation>
      <xs:documentation>alpha</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="origin">
    <xs:annotation>
      <xs:documentation>auto | length length</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="overflow">
    <xs:restriction base="xs:token">
      <xs:enumeration value="visible"/>
      <xs:enumeration value="hidden"/>
      <xs:enumeration value="dynamic"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="padding">
    <xs:annotation>
      <xs:documentation>length length | length length length | length length length length</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="pixelAspectRatio">
    <xs:annotation>
      <xs:documentation>positiveInteger:positiveInteger</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string">
      <xs:pattern value="\p{Nd}+\s*:\s*\p{Nd}+"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="profile">
    <xs:restriction base="xs:anyURI"/>
  </xs:simpleType>
  <xs:simpleType name="role">
    <xs:annotation>
      <xs:documentation>metadataRoleBaseType | "x-"string</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:NMTOKENS"/>
  </xs:simpleType>
  <xs:simpleType name="showBackground">
    <xs:restriction base="xs:token">
      <xs:enumeration value="always"/>
      <xs:enumeration value="whenActive"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="smpteMode">
    <xs:restriction base="xs:token">
      <xs:enumeration value="dropNTSC"/>
      <xs:enumeration value="dropPAL"/>
      <xs:enumeration value="nonDrop"/>
    </xs:restriction>
  </xs:simpleType>

  <xs:simpleType name="subFrameRate">
    <xs:restriction base="xs:positiveInteger"/>
  </xs:simpleType>
  <xs:simpleType name="textAlign">
    <xs:restriction base="xs:token">
      <xs:enumeration value="left"/>
      <xs:enumeration value="center"/>
      <xs:enumeration value="right"/>
      <xs:enumeration value="start"/>
      <xs:enumeration value="end"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="textDecoration">
    <xs:restriction base="xs:token">
      <xs:enumeration value="none"/>
      <xs:enumeration value="underline"/>
      <xs:enumeration value="noUnderline"/>
      <xs:enumeration value="overline"/>
      <xs:enumeration value="noOverline"/>
      <xs:enumeration value="lineThrough"/>
      <xs:enumeration value="noLineThrough"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="textOutline">
    <xs:annotation>
      <xs:documentation>none | length | length length | color length | color length length</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="tickRate">
    <xs:restriction base="xs:positiveInteger"/>
  </xs:simpleType>
  <xs:simpleType name="timeBase">
    <xs:restriction base="xs:token">
      <xs:enumeration value="media"/>
      <xs:enumeration value="smpte"/>
      <xs:enumeration value="clock"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="timeContainer">
    <xs:restriction base="xs:token">
      <xs:enumeration value="par"/>
      <xs:enumeration value="seq"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="timeCoordinate">
    <xs:annotation>
      <xs:documentation>timeExpression</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="timeDuration">
    <xs:annotation>
      <xs:documentation>timeExpression</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
  <xs:simpleType name="unicodeBidi">
    <xs:restriction base="xs:token">
      <xs:enumeration value="normal"/>
      <xs:enumeration value="embed"/>
      <xs:enumeration value="bidiOverride"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="visibility">
    <xs:restriction base="xs:token">
      <xs:enumeration value="hidden"/>
      <xs:enumeration value="visible"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="wrapOption">
    <xs:restriction base="xs:token">
      <xs:enumeration value="wrap"/>
      <xs:enumeration value="noWrap"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="writingMode">
    <xs:restriction base="xs:token">
      <xs:enumeration value="lrtb"/>
      <xs:enumeration value="rltb"/>
      <xs:enumeration value="tbrl"/>
      <xs:enumeration value="tblr"/>
      <xs:enumeration value="lr"/>
      <xs:enumeration value="rl"/>
      <xs:enumeration value="tb"/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name="zIndex">
    <xs:annotation>
      <xs:documentation>auto | integer</xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string"/>
  </xs:simpleType>
</xs:schema>

C.2.2.5 Document Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata"
  xmlns:ttp="http://www.w3.org/2006/10/ttaf1#parameter"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#metadata"
    schemaLocation="ttaf1-dfxp-metadata-items.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#parameter"
    schemaLocation="ttaf1-dfxp-parameter-items.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#styling"
    schemaLocation="ttaf1-dfxp-styling-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-timing-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-head.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-content.xsd"/>
  <xs:attributeGroup name="tt.attlist">
    <xs:attributeGroup ref="tt:Core.required.attrib.class"/>
    <xs:attributeGroup ref="ttp:Parameter.attrib.class"/>
  </xs:attributeGroup>
  <xs:complexType name="tt.eltype">
    <xs:sequence>
      <xs:element ref="tt:head" minOccurs="0" maxOccurs="1"/>
      <xs:element ref="tt:body" minOccurs="0" maxOccurs="1"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:tt.attlist"/>
  </xs:complexType>
  <xs:element name="tt" type="tt:tt.eltype"/>
</xs:schema>

C.2.2.6 Header Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata"
  xmlns:ttp="http://www.w3.org/2006/10/ttaf1#parameter"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-metadata.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-parameters.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-styling.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-layout.xsd"/>
  <xs:attributeGroup name="head.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
  </xs:attributeGroup>
  <xs:complexType name="head.eltype">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:group ref="tt:Parameters.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="tt:styling" minOccurs="0" maxOccurs="1"/>
      <xs:element ref="tt:layout" minOccurs="0" maxOccurs="1"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:head.attlist"/>
  </xs:complexType>
  <xs:element name="head" type="tt:head.eltype"/>
</xs:schema>

C.2.2.7 Layout Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-timing-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-metadata.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-animation.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-styling.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#styling"
    schemaLocation="ttaf1-dfxp-styling-attribs.xsd"/>
  <xs:attributeGroup name="RegionBinding.attrib.class">
    <xs:attribute name="region" type="xs:IDREF"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="layout.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="region.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
    <xs:attributeGroup ref="tt:Styled.attrib.class"/>
    <xs:attributeGroup ref="tt:TimedContainer.attrib.class"/>
  </xs:attributeGroup>
  <xs:complexType name="layout.eltype">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="tt:region" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:layout.attlist"/>
  </xs:complexType>
  <xs:complexType name="region.eltype">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:group ref="tt:Animation.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="tt:style" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:region.attlist"/>
  </xs:complexType>
  <xs:element name="layout" type="tt:layout.eltype"/>
  <xs:element name="region" type="tt:region.eltype"/>
</xs:schema>

C.2.2.8 Metadata Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata">
  <xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#metadata"
    schemaLocation="ttaf1-dfxp-metadata-items.xsd"/>
  <xs:attributeGroup name="metadata.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
  </xs:attributeGroup>
  <xs:complexType name="metadata.eltype" mixed="true">
    <xs:sequence>
      <xs:any namespace="##other" processContents="lax" minOccurs="0"
        maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:metadata.attlist"/>
  </xs:complexType>
  <xs:element name="metadata" type="tt:metadata.eltype"/>
  <xs:group name="MetadataNoAgent.class">

  <xs:group name="Metadata.class">

    <xs:choice>
      <xs:group ref="ttm:MetadataItems.class"/>
      <xs:element ref="tt:metadata"/>
    </xs:choice>
  </xs:group>
  <xs:group name="Metadata.class">
    <xs:choice>
      <xs:group ref="tt:MetadataNoAgent.class"/>
      <xs:element ref="ttm:agent"/>
    </xs:choice>
  </xs:group>

</xs:schema>

C.2.2.9 Metadata Items Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1#metadata"
  xml:lang="en" xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:ttd="http://www.w3.org/2006/10/ttaf1#datatype"
  xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata">
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#datatype"
    schemaLocation="ttaf1-dfxp-datatypes.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1"
    schemaLocation="ttaf1-dfxp-core-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-metadata-attribs.xsd"/>
  <xs:attributeGroup name="actor.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
    <xs:attribute name="agent" type="xs:IDREF"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="agent.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
    <xs:attribute name="type" type="ttd:metadataAgentType"
    use="required"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="copyright.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="desc.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="name.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
    <xs:attribute name="type" type="ttd:metadataNameType"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="title.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
  </xs:attributeGroup>
  <xs:complexType name="actor.eltype">
    <xs:attributeGroup ref="ttm:actor.attlist"/>
  </xs:complexType>
  <xs:complexType name="agent.eltype">
    <xs:sequence>
      <xs:element ref="ttm:name" minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="ttm:actor" minOccurs="0" maxOccurs="1"/>
    </xs:sequence>
    <xs:attributeGroup ref="ttm:agent.attlist"/>
  </xs:complexType>
  <xs:complexType name="copyright.eltype" mixed="true">
    <xs:attributeGroup ref="ttm:copyright.attlist"/>
  </xs:complexType>
  <xs:complexType name="desc.eltype" mixed="true">
    <xs:attributeGroup ref="ttm:desc.attlist"/>
  </xs:complexType>
  <xs:complexType name="name.eltype" mixed="true">
    <xs:attributeGroup ref="ttm:name.attlist"/>
  </xs:complexType>
  <xs:complexType name="title.eltype" mixed="true">
    <xs:attributeGroup ref="ttm:title.attlist"/>
  </xs:complexType>
  <xs:element name="actor" type="ttm:actor.eltype"/>
  <xs:element name="agent" type="ttm:agent.eltype"/>
  <xs:element name="copyright" type="ttm:copyright.eltype"/>
  <xs:element name="desc" type="ttm:desc.eltype"/>
  <xs:element name="name" type="ttm:name.eltype"/>
  <xs:element name="title" type="ttm:title.eltype"/>
  <xs:group name="MetadataItems.class">
    <xs:choice>
      <xs:element ref="ttm:title"/>
      <xs:element ref="ttm:desc"/>

      <xs:element ref="ttm:agent"/>

      <xs:element ref="ttm:copyright"/>
      <xs:element ref="ttm:desc"/>
      <xs:element ref="ttm:title"/>

    </xs:choice>
  </xs:group>
</xs:schema>

C.2.2.10 Metadata Attributes Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1#metadata"
  xml:lang="en" xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:ttd="http://www.w3.org/2006/10/ttaf1#datatype"
  xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata">
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#datatype"
    schemaLocation="ttaf1-dfxp-datatypes.xsd"/>
  <xs:attribute name="agent" type="ttd:agent"/>
  <xs:attribute name="role" type="ttd:role"/>
  <xs:attributeGroup name="Metadata.attrib.class">
    <xs:attribute ref="ttm:agent"/>
    <xs:attribute ref="ttm:role"/>
  </xs:attributeGroup>
</xs:schema>

C.2.2.11 Parameters Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:ttp="http://www.w3.org/2006/10/ttaf1#parameter">
  <xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#parameter"
    schemaLocation="ttaf1-dfxp-parameter-items.xsd"/>
  <xs:group name="Parameters.class">
    <xs:choice>
      <xs:group ref="ttp:ParameterItems.class"/>
    </xs:choice>
  </xs:group>
</xs:schema>

C.2.2.12 Parameter Items Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1#parameter"
  xml:lang="en" xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:ttd="http://www.w3.org/2006/10/ttaf1#datatype"
  xmlns:ttp="http://www.w3.org/2006/10/ttaf1#parameter">
  <xs:import namespace="http://www.w3.org/XML/1998/namespace"
    schemaLocation="xml.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#datatype"
    schemaLocation="ttaf1-dfxp-datatypes.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1"
    schemaLocation="ttaf1-dfxp-core-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-parameter-attribs.xsd"/>
  <xs:attributeGroup name="profile.attlist">
    <xs:attributeGroup ref="tt:Core.ID.attrib.class"/>
    <xs:attribute name="use" type="ttd:profile"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="features.attlist">
    <xs:attributeGroup ref="tt:Core.ID.attrib.class"/>
    <xs:attribute ref="xml:base"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="feature.attlist">
    <xs:attributeGroup ref="tt:Core.ID.attrib.class"/>
    <xs:attribute name="value" type="ttd:featureValue"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="extensions.attlist">
    <xs:attributeGroup ref="tt:Core.ID.attrib.class"/>
    <xs:attribute ref="xml:base"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="extension.attlist">
    <xs:attributeGroup ref="tt:Core.ID.attrib.class"/>
    <xs:attribute name="value" type="ttd:extensionValue"/>
  </xs:attributeGroup>
  <xs:complexType name="profile.eltype">
    <xs:sequence>
      <xs:element ref="ttp:features" minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="ttp:extensions" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="ttp:profile.attlist"/>
  </xs:complexType>
  <xs:complexType name="features.eltype">
    <xs:sequence>
      <xs:element ref="ttp:feature" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="ttp:features.attlist"/>
  </xs:complexType>
  <xs:complexType name="feature.eltype">
    <xs:simpleContent>
          <xs:extension base="ttd:featureDesignator">
            <xs:attributeGroup ref="ttp:feature.attlist"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
  <xs:complexType name="extensions.eltype">
    <xs:sequence>
      <xs:element ref="ttp:extension" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="ttp:extensions.attlist"/>
  </xs:complexType>
  <xs:complexType name="extension.eltype">
    <xs:simpleContent>
          <xs:extension base="ttd:extensionDesignator">
            <xs:attributeGroup ref="ttp:extension.attlist"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
  <xs:element name="profile" type="ttp:profile.eltype"/>
  <xs:element name="features" type="ttp:features.eltype"/>
  <xs:element name="feature" type="ttp:feature.eltype"/>
  <xs:element name="extensions" type="ttp:extensions.eltype"/>
  <xs:element name="extension" type="ttp:extension.eltype"/>
  <xs:group name="ParameterItems.class">
    <xs:choice>
      <xs:element ref="ttp:profile"/>
    </xs:choice>
  </xs:group>
</xs:schema>

C.2.2.13 Parameter Attributes Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1#parameter"
  xml:lang="en" xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:ttd="http://www.w3.org/2006/10/ttaf1#datatype"
  xmlns:ttp="http://www.w3.org/2006/10/ttaf1#parameter">
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#datatype"
    schemaLocation="ttaf1-dfxp-datatypes.xsd"/>
  <xs:attribute name="cellResolution" type="ttd:cellResolution"/>
  <xs:attribute name="clockMode" type="ttd:clockMode"/>
  <xs:attribute name="dropMode" type="ttd:dropMode"/>

  <xs:attribute name="frameRate" type="ttd:frameRate"/>
  <xs:attribute name="frameRateMultiplier" type="ttd:frameRateMultiplier"/>
  <xs:attribute name="markerMode" type="ttd:markerMode"/>
  <xs:attribute name="profile" type="ttd:profile"/>
  <xs:attribute name="pixelAspectRatio" type="ttd:pixelAspectRatio"/>
  <xs:attribute name="smpteMode" type="ttd:smpteMode"/>

  <xs:attribute name="subFrameRate" type="ttd:subFrameRate"/>
  <xs:attribute name="tickRate" type="ttd:tickRate"/>
  <xs:attribute name="timeBase" type="ttd:timeBase"/>
  <xs:attributeGroup name="Parameter.attrib.class">
    <xs:attribute ref="ttp:cellResolution"/>
    <xs:attribute ref="ttp:clockMode"/>
    <xs:attribute ref="ttp:dropMode"/>

    <xs:attribute ref="ttp:frameRate"/>
    <xs:attribute ref="ttp:frameRateMultiplier"/>
    <xs:attribute ref="ttp:markerMode"/>
    <xs:attribute ref="ttp:profile"/>
    <xs:attribute ref="ttp:pixelAspectRatio"/>
    <xs:attribute ref="ttp:smpteMode"/>

    <xs:attribute ref="ttp:subFrameRate"/>
    <xs:attribute ref="ttp:tickRate"/>
    <xs:attribute ref="ttp:timeBase"/>
  </xs:attributeGroup>
</xs:schema>

C.2.2.14 Styling Attributes Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1#styling" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:ttd="http://www.w3.org/2006/10/ttaf1#datatype"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#datatype"
    schemaLocation="ttaf1-dfxp-datatypes.xsd"/>
  <xs:attribute name="backgroundColor" type="ttd:color"/>
  <xs:attribute name="color" type="ttd:color"/>
  <xs:attribute name="direction" type="ttd:direction"/>
  <xs:attribute name="display" type="ttd:display"/>
  <xs:attribute name="displayAlign" type="ttd:displayAlign"/>
  <xs:attribute name="dynamicFlow" type="ttd:dynamicFlow"/>
  <xs:attribute name="extent" type="ttd:extent"/>
  <xs:attribute name="fontFamily" type="ttd:fontFamily"/>
  <xs:attribute name="fontSize" type="ttd:fontSize"/>
  <xs:attribute name="fontStyle" type="ttd:fontStyle"/>
  <xs:attribute name="fontWeight" type="ttd:fontWeight"/>
  <xs:attribute name="lineHeight" type="ttd:lineHeight"/>
  <xs:attribute name="opacity" type="ttd:opacity"/>
  <xs:attribute name="origin" type="ttd:origin"/>
  <xs:attribute name="overflow" type="ttd:overflow"/>
  <xs:attribute name="padding" type="ttd:padding"/>
  <xs:attribute name="showBackground" type="ttd:showBackground"/>
  <xs:attribute name="textAlign" type="ttd:textAlign"/>
  <xs:attribute name="textDecoration" type="ttd:textDecoration"/>
  <xs:attribute name="textOutline" type="ttd:textOutline"/>
  <xs:attribute name="unicodeBidi" type="ttd:unicodeBidi"/>
  <xs:attribute name="visibility" type="ttd:visibility"/>
  <xs:attribute name="wrapOption" type="ttd:wrapOption"/>
  <xs:attribute name="writingMode" type="ttd:writingMode"/>
  <xs:attribute name="zIndex" type="ttd:zIndex"/>
  <xs:attributeGroup name="Styling.attrib.class">
    <xs:attribute ref="tts:backgroundColor"/>
    <xs:attribute ref="tts:color"/>
    <xs:attribute ref="tts:direction"/>
    <xs:attribute ref="tts:display"/>
    <xs:attribute ref="tts:displayAlign"/>
    <xs:attribute ref="tts:dynamicFlow"/>
    <xs:attribute ref="tts:extent"/>
    <xs:attribute ref="tts:fontFamily"/>
    <xs:attribute ref="tts:fontSize"/>
    <xs:attribute ref="tts:fontStyle"/>
    <xs:attribute ref="tts:fontWeight"/>
    <xs:attribute ref="tts:lineHeight"/>
    <xs:attribute ref="tts:opacity"/>
    <xs:attribute ref="tts:origin"/>
    <xs:attribute ref="tts:overflow"/>
    <xs:attribute ref="tts:padding"/>
    <xs:attribute ref="tts:showBackground"/>
    <xs:attribute ref="tts:textAlign"/>
    <xs:attribute ref="tts:textDecoration"/>
    <xs:attribute ref="tts:textOutline"/>
    <xs:attribute ref="tts:unicodeBidi"/>
    <xs:attribute ref="tts:visibility"/>
    <xs:attribute ref="tts:wrapOption"/>
    <xs:attribute ref="tts:writingMode"/>
    <xs:attribute ref="tts:zIndex"/>
  </xs:attributeGroup>
</xs:schema>

C.2.2.15 Styling Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1"
  xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata"
  xmlns:tts="http://www.w3.org/2006/10/ttaf1#styling">
  <xs:include schemaLocation="ttaf1-dfxp-core-attribs.xsd"/>
  <xs:include schemaLocation="ttaf1-dfxp-metadata.xsd"/>
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#styling"
    schemaLocation="ttaf1-dfxp-styling-attribs.xsd"/>
  <xs:attributeGroup name="StyleBinding.attrib.class">
    <xs:attribute name="style" type="xs:IDREFS"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="Styled.attrib.class">
    <xs:attributeGroup ref="tt:StyleBinding.attrib.class"/>
    <xs:attributeGroup ref="tts:Styling.attrib.class"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="styling.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="style.attlist">
    <xs:attributeGroup ref="tt:Core.attrib.class"/>
    <xs:attributeGroup ref="tt:Styled.attrib.class"/>
  </xs:attributeGroup>
  <xs:complexType name="styling.eltype">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="tt:style" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:styling.attlist"/>
  </xs:complexType>
  <xs:complexType name="style.eltype">
    <xs:sequence>
      <xs:group ref="tt:Metadata.class" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attributeGroup ref="tt:style.attlist"/>
  </xs:complexType>
  <xs:element name="styling" type="tt:styling.eltype"/>
  <xs:element name="style" type="tt:style.eltype"/>
</xs:schema>

C.2.2.16 Timing Attributes Module

<xs:schema targetNamespace="http://www.w3.org/2006/10/ttaf1" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:ttd="http://www.w3.org/2006/10/ttaf1#datatype"
  xmlns:tt="http://www.w3.org/2006/10/ttaf1">
  <xs:import namespace="http://www.w3.org/2006/10/ttaf1#datatype"
    schemaLocation="ttaf1-dfxp-datatypes.xsd"/>
  <xs:attributeGroup name="TimingInterval.attrib.class">
    <xs:attribute name="begin" type="ttd:timeCoordinate"/>
    <xs:attribute name="dur" type="ttd:timeDuration"/>
    <xs:attribute name="end" type="ttd:timeCoordinate"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="TimingContainer.attrib.class">
    <xs:attribute name="timeContainer" type="ttd:timeContainer"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="Timed.attrib.class">
    <xs:attributeGroup ref="tt:TimingInterval.attrib.class"/>
  </xs:attributeGroup>
  <xs:attributeGroup name="TimedContainer.attrib.class">
    <xs:attributeGroup ref="tt:Timed.attrib.class"/>
    <xs:attributeGroup ref="tt:TimingContainer.attrib.class"/>
  </xs:attributeGroup>
</xs:schema>

C.2.2.17 XML Attributes Module

<xs:schema targetNamespace="http://www.w3.org/XML/1998/namespace" xml:lang="en"
  xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:attribute name="base" type="xs:anyURI"/>
  <xs:attribute name="id" type="xs:ID"/>
  <xs:attribute name="lang" type="xs:language"/>
  <xs:attribute name="space">
    <xs:simpleType>
      <xs:restriction base="xs:NCName">
        <xs:enumeration value="default"/>
        <xs:enumeration value="preserve"/>
      </xs:restriction>
    </xs:simpleType>
  </xs:attribute>
</xs:schema>

D Media Type Registration

This appendix is normative.

This appendix registers a new MIME media type, "application/ttaf+xml" in conformance with BCP 13 and W3CRegMedia . The information in this appendix is being submitted to the Internet Engineering Steering Group (IESG) for review, approval, and registration with the Internet Assigned Numbers Authority (IANA).

MIME media type name:

application

MIME subtype name:

ttaf+xml

Required parameters:

None.

Optional parameters:

The encoding of a TT AF document must be determined by the XML encoding declaration. This has identical semantics to the application/xml media type in the case where the charset parameter is omitted, as specified in [XML Media] , Sections 8.9, 8.10 and 8.11.

The document profile of a TT AF document may be specified using an optional profile parameter, which, if specified, the value of which must adhere to the syntax and semantics of ttp:profile parameter defined by Section ~~6.2.7~~ 6.2.8 ttp:profile of the published specification.

Encoding considerations:

Same for application/xml. See [XML Media] , Section 3.2.

Restrictions on usage:

None.

Security considerations:

As with other XML types and as noted in [XML Media] Section 10, repeated expansion of maliciously constructed XML entities can be used to consume large amounts of memory, which may cause XML processors in constrained environments to fail.

In addition, because of the extensibility features for TT AF and of XML in general, it is possible that "application/ttaf+xml" may describe content that has security implications beyond those described here. However, if the processor follows only the normative semantics of the published specification, this content will be outside TT AF namespaces and may be ignored. Only in the case where the processor recognizes and processes the additional content, or where further processing of that content is dispatched to other processors, would security issues potentially arise. And in that case, they would fall outside the domain of this registration document.

Interoperability considerations:

The published specification describes processing semantics that dictate behavior that must be followed when dealing with, among other things, unrecognized elements and attributes, both in TT AF namespaces and in other namespaces.

Because TT AF is extensible, conformant "application/ttaf+xml" processors must expect that content received is well-formed XML, but it cannot be guaranteed that the content is valid to a particular DTD or Schema or that the processor will recognize all of the elements and attributes in the document.

Published specification:

This media type registration is extracted from Appendix D Media Type Registration of the Timed Text (TT) Authoring Format 1.0 - Distribution Format Exchange Profile (DFXP) specification.

Additional information:

None.

Person & email address to contact for further information:

Glenn Adams (public-tt@w3.org)

Intended usage:

COMMON

Author/Change controller:

The published specification is a work product of the World Wide Web Consortium's Timed Text (TT) Working Group. The W3C has change control over this specification.

E Features

This appendix is normative.

This appendix specifies (1) a set of feature designations, each of which labels one or more syntactic and/or semantic features defined by this specification, and (2) for each designated feature, whether the feature is mandatory or optional for a transformation or presentation processor.

E.1 Feature Designations

A feature designation is expressed as a string that adheres to the following form:

feature-designation
  : feature-namespace designation
feature-namespace
  :                     // http://www.w3.org/2006/10/ttaf1/feature

  : TT Feature Namespace                    // http://www.w3.org/2006/10/ttaf1/feature/

designation
  : "#" token-char+
token-char
  : { XML NameChar }                        // XML 1.1 Production [4a]

All values of feature-designation not defined by this specification are reserved for future standardization.

The following sub-sections define all feature designations, expressed as relative URIs (fragment identifiers) with respect to the TT Feature Namespace base URI.

E.1.1 #animation

A TT AF transformation processor supports the #animation feature if it recognizes and is capable of transforming the following vocabulary defined by 11 Animation :

set

A TT AF presentation processor supports the #animation feature if it implements presentation semantic support for the same vocabulary enumerated above.

E.1.2 #backgroundColor

A TT AF transformation processor supports the #backgroundColor feature if it recognizes and is capable of transforming the tts:backgroundColor attribute.

A TT AF presentation processor supports the #backgroundColor feature if it (1) implements presentation semantic support for the tts:backgroundColor attribute and (2) is capable of displaying or generating an output display signal that distinguishes between at least sixteen (16) values of color, including all primary and secondary colors of the SRGB color space.

E.1.3 #backgroundColor-block

A TT AF transformation processor supports the #backgroundColor-block feature if it recognizes and is capable of transforming all defined values of the tts:backgroundColor attribute when applied to a content element that would generate a block area during presentation processing.

A TT AF presentation processor supports the #backgroundColor-block feature if it (1) implements presentation semantic support for the tts:backgroundColor attribute when applied to a content element that generates a block area and (2) is capable of displaying or generating an output display signal that distinguishes between at least sixteen (16) values of color, including all primary and secondary colors of the SRGB color space.

E.1.4 #backgroundColor-inline

A TT AF transformation processor supports the #backgroundColor-inline feature if it recognizes and is capable of transforming all defined values of the tts:backgroundColor attribute when applied to a content element that would generate an inline area during presentation processing.

A TT AF presentation processor supports the #backgroundColor-inline feature if it (1) implements presentation semantic support for the tts:backgroundColor attribute when applied to a content element that generates an inline area and (2) is capable of displaying or generating an output display signal that distinguishes between at least sixteen (16) values of color, including all primary and secondary colors of the SRGB color space.

E.1.5 #backgroundColor-region

A TT AF transformation processor supports the #backgroundColor-region feature if it recognizes and is capable of transforming all defined values of the tts:backgroundColor attribute when applied to a region element.

A TT AF presentation processor supports the #backgroundColor-region feature if it (1) implements presentation semantic support for the tts:backgroundColor attribute when applied to a region element and (2) is capable of displaying or generating an output display signal that distinguishes between at least sixteen (16) values of color, including all primary and secondary colors of the SRGB color space .

E.1.6 #bidi

A TT AF processor supports the #bidi feature if it supports the following features:

#direction
#unicodeBidi
#writingMode-horizontal

E.1.7 #cellResolution

A TT AF transformation processor supports the #cellResolution feature if it recognizes and is capable of transforming the ttp:cellResolution attribute.

A TT AF presentation processor supports the #cellResolution feature if it implements presentation semantic support for the ttp:cellResolution attribute.

E.1.8 #clockMode

A TT AF transformation processor supports the #clockMode feature if it recognizes and is capable of transforming the ttp:clockMode attribute.

A TT AF presentation processor supports the #clockMode feature if it implements presentation semantic support for the ttp:clockMode attribute.

E.1.9 #clockMode-gps

A TT AF transformation processor supports the #clockMode-gps feature if it recognizes and is capable of transforming the gps value of the ttp:clockMode attribute.

A TT AF presentation processor supports the #clockMode-gps feature if it implements presentation semantic support for the gps value of the ttp:clockMode attribute.

E.1.10 #clockMode-local

A TT AF transformation processor supports the #clockMode-local feature if it recognizes and is capable of transforming the local value of the ttp:clockMode attribute.

A TT AF presentation processor supports the #clockMode-local feature if it implements presentation semantic support for the local value of the ttp:clockMode attribute.

E.1.11 #clockMode-utc

A TT AF transformation processor supports the #clockMode-utc feature if it recognizes and is capable of transforming the utc value of the ttp:clockMode attribute.

A TT AF presentation processor supports the #clockMode-utc feature if it implements presentation semantic support for the utc value of the ttp:clockMode attribute.

E.1.9 E.1.12 #color

A TT AF transformation processor supports the #color feature if it recognizes and is capable of transforming the tts:color attribute.

A TT AF presentation processor supports the #color feature if it (1) implements presentation semantic support for the tts:color attribute and (2) is capable of displaying or generating an output display signal that distinguishes between at least sixteen (16) values of color, including all primary and secondary colors of the SRGB color space.

E.1.10 E.1.13 #content

A TT AF transformation processor supports the #content feature if it recognizes and is capable of transforming the following vocabulary defined by 7 Content :

body
div
p
span
br

A TT AF presentation processor supports the #content feature if it implements presentation semantic support for the same vocabulary enumerated above.

E.1.11 E.1.14 #core

A TT AF transformation processor supports the #core feature if it recognizes and is capable of transforming the following core attributes vocabulary defined by 7 Content :

@ xml:id
@ xml:lang
@ xml:space

A TT AF presentation processor supports the #core feature if it implements presentation semantic support for the same vocabulary enumerated above.

E.1.12 E.1.15 #direction

A TT AF transformation processor supports the #direction feature if it recognizes and is capable of transforming all defined values of the tts:direction attribute.

A TT AF presentation processor supports the #direction feature if it implements presentation semantic support for all defined values of the tts:direction attribute.

E.1.13 E.1.16 #display

A TT AF transformation processor supports the #display feature if it recognizes and is capable of transforming all defined values of the tts:display attribute.

A TT AF presentation processor supports the #display feature if it implements presentation semantic support for all defined values of the tts:display attribute.

E.1.14 E.1.17 #display-block

A TT AF transformation processor supports the #display-block feature if it recognizes and is capable of transforming all defined values of the tts:display attribute when applied to a content element that would generate a block area during presentation processing.

A TT AF presentation processor supports the #display-block feature if it implements presentation semantic support for all defined values of the tts:display attribute when applied to a content element that generates a block area.

E.1.15 E.1.18 #display-inline

A TT AF transformation processor supports the #display-inline feature if it recognizes and is capable of transforming all defined values of the tts:display attribute when applied to a content element that would generate an inline area during presentation processing.

A TT AF presentation processor supports the #display-inline feature if it implements presentation semantic support for all defined values of the tts:display attribute when applied to a content element that generates an inline area.

E.1.16 E.1.19 #display-region

A TT AF transformation processor supports the #display-region feature if it recognizes and is capable of transforming all defined values of the tts:display attribute when applied to a region element.

A TT AF presentation processor supports the #display-region feature if it implements presentation semantic support for all defined values of the tts:display attribute when applied to a region element.

E.1.17 E.1.20 #displayAlign

A TT AF transformation processor supports the #displayAlign feature if it recognizes and is capable of transforming all defined values of the tts:displayAlign attribute.

A TT AF presentation processor supports the #displayAlign feature if it implements presentation semantic support for all defined values of the tts:displayAlign attribute.

E.1.21 # dropMode

A TT AF transformation processor supports the # dropMode feature if it recognizes and is capable of transforming the ttp: dropMode attribute.

A TT AF presentation processor supports the # dropMode feature if it implements presentation semantic support for the ttp: dropMode attribute.

E.1.22 #dropMode-dropNTSC

A TT AF transformation processor supports the #dropMode-dropNTSC feature if it recognizes and is capable of transforming the dropNTSC value of the ttp:dropMode attribute.

A TT AF presentation processor supports the #dropMode-dropNTSC feature if it implements presentation semantic support for the dropNTSC value of the ttp:dropMode attribute.

E.1.23 #dropMode-dropPAL

A TT AF transformation processor supports the #dropMode-dropPAL feature if it recognizes and is capable of transforming the dropPAL value of the ttp:dropMode attribute.

A TT AF presentation processor supports the #dropMode-dropPAL feature if it implements presentation semantic support for the dropPAL value of the ttp:dropMode attribute.

E.1.24 #dropMode-nonDrop

A TT AF transformation processor supports the #dropMode-nonDrop feature if it recognizes and is capable of transforming the nonDrop value of the ttp:dropMode attribute.

A TT AF presentation processor supports the #dropMode-nonDrop feature if it implements presentation semantic support for the nonDrop value of the ttp:dropMode attribute.

E.1.18 E.1.25 #dynamicFlow

A TT AF transformation processor supports the #dynamicFlow feature if it recognizes and is capable of transforming all defined values of the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow feature if it implements presentation semantic support for all defined values of the tts:dynamicFlow attribute.

E.1.19 E.1.26 #dynamicFlow-character

A TT AF transformation processor supports the #dynamicFlow-character feature if it recognizes and is capable of transforming the flow unit character as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow-character feature if it implements presentation semantic support for the flow unit character as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

E.1.20 E.1.27 #dynamicFlow-clear

A TT AF transformation processor supports the #dynamicFlow-clear feature if it recognizes and is capable of transforming the flow interval function clear(..) as defined by 8.3.7 <flowIntervalFunction> when used with the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow-clear feature if it implements presentation semantic support for the flow interval function clear(..) as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

E.1.21 E.1.28 #dynamicFlow-fill

A TT AF transformation processor supports the #dynamicFlow-fill feature if it recognizes and is capable of transforming the flow interval function fill(..) as defined by 8.3.7 <flowIntervalFunction> when used with the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow-fill feature if it implements presentation semantic support for the flow interval function fill(..) as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

E.1.22 E.1.29 #dynamicFlow-glyph

A TT AF transformation processor supports the #dynamicFlow-glyph feature if it recognizes and is capable of transforming the flow unit glyph as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow-glyph feature if it implements presentation semantic support for the flow unit glyph as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

E.1.23 E.1.30 #dynamicFlow-in

A TT AF transformation processor supports the #dynamicFlow-in feature if it recognizes and is capable of transforming the flow function in(..) as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow-in feature if it implements presentation semantic support for the flow function in(..) as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

E.1.24 E.1.31 #dynamicFlow-jump

A TT AF transformation processor supports the #dynamicFlow-jump feature if it recognizes and is capable of transforming the flow style jump as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow-jump feature if it implements presentation semantic support for the flow style jump as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

E.1.25 E.1.32 #dynamicFlow-line

A TT AF transformation processor supports the #dynamicFlow-line feature if it recognizes and is capable of transforming (1) the flow unit line as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow ~~attribute.~~ attribute and (2) the flow interval argument break as defined by 8.3.7 <flowIntervalFunction> .

A TT AF presentation processor supports the #dynamicFlow-line feature if it implements presentation semantic support for (1) the flow unit line as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow ~~attribute.~~ attribute and (2) the flow interval argument break as defined by 8.3.7 <flowIntervalFunction> .

E.1.26 E.1.33 #dynamicFlow-out

A TT AF transformation processor supports the #dynamicFlow-out feature if it recognizes and is capable of transforming the flow function out(..) as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow-out feature if it implements presentation semantic support for the flow function out(..) as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

E.1.27 E.1.34 #dynamicFlow-rollUp

A TT AF transformation processor supports the #dynamicFlow-rollUp feature if it recognizes and is capable of transforming the rollUp value of the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow-rollUp feature if it implements presentation semantic support for the rollUp of the tts:dynamicFlow attribute.

E.1.28 E.1.35 #dynamicFlow-smooth

A TT AF transformation processor supports the #dynamicFlow-smooth feature if it recognizes and is capable of transforming the flow style smooth as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow-smooth feature if it implements presentation semantic support for the flow style smooth as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

E.1.29 E.1.36 #dynamicFlow-teletext

A TT AF transformation processor supports the #dynamicFlow-teletext feature if it recognizes and is capable of transforming any well-defined value of the tts:dynamicFlow attribute that is equivalent to in(glyph,jump) out(line,jump) .

A TT AF presentation processor supports the #dynamicFlow-teletext feature if it implements presentation semantic support for any well-defined value of the tts:dynamicFlow attribute that is equivalent to in(glyph,jump) out(line,jump) .

E.1.30 E.1.37 #dynamicFlow-word

A TT AF transformation processor supports the #dynamicFlow-word feature if it recognizes and is capable of transforming the flow unit word as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

A TT AF presentation processor supports the #dynamicFlow-word feature if it implements presentation semantic support for the flow unit word as defined by 8.3.6 <flowFunction> when used with the tts:dynamicFlow attribute.

E.1.31 E.1.38 #extent

A TT AF transformation processor supports the #extent feature if it recognizes and is capable of transforming the tts:extent attribute.

A TT AF presentation processor supports the #extent feature if it implements presentation semantic support for the tts:extent attribute.

E.1.39 #extent-region

A TT AF transformation processor supports the #extent-region feature if it recognizes and is capable of transforming the tts:extent attribute when applied to a region element.

A TT AF presentation processor supports the #extent-region feature if it implements presentation semantic support for the tts:extent attribute when applied to a region element.

E.1.40 #extent-root

A TT AF transformation processor supports the #extent-root feature if it recognizes and is capable of transforming the tts:extent attribute when applied to the tt element.

A TT AF presentation processor supports the #extent-root feature if it implements presentation semantic support for the tts:extent attribute when applied to a tt element.

E.1.32 E.1.41 #fontFamily

A TT AF transformation processor supports the #fontFamily feature if it recognizes and is capable of transforming the tts:fontFamily attribute.

A TT AF presentation processor supports the #fontFamily feature if it implements presentation semantic support for the tts:fontFamily attribute.

E.1.33 E.1.42 #fontFamily-generic

A TT AF transformation processor supports the #fontFamily-generic feature if it recognizes and is capable of transforming <genericFamilyName> values when used with the tts:fontFamily attribute.

A TT AF presentation processor supports the #fontFamily-generic feature if it implements presentation semantic support for <genericFamilyName> values when used with the tts:fontFamily attribute.

E.1.34 E.1.43 #fontFamily-non-generic

A TT AF transformation processor supports the #fontFamily-non-generic feature if it recognizes and is capable of transforming <familyName> values when used with the tts:fontFamily attribute.

A TT AF presentation processor supports the #fontFamily-non-generic feature if it implements presentation semantic support for <familyName> values when used with the tts:fontFamily attribute.

E.1.35 E.1.44 #fontSize

A TT AF transformation processor supports the #fontSize feature if it recognizes and is capable of transforming the tts:fontSize attribute.

A TT AF presentation processor supports the #fontSize feature if it implements presentation semantic support for the tts:fontSize attribute.

E.1.36 #fontSize-anisomorphic E.1.45 #fontSize- anamorphic

A TT AF transformation processor supports the #fontSize-anisomorphic #fontSize- anamorphic feature if it recognizes and is capable of transforming values of the tts:fontSize attribute that consist of two <length> specifications.

A TT AF presentation processor supports the #fontSize-anisomorphic #fontSize- anamorphic feature if it implements presentation semantic support for defined values of the tts:fontSize attribute that consist of two <length> specifications.

E.1.37 E.1.46 #fontSize-isomorphic

A TT AF transformation processor supports the #fontSize-isomorphic feature if it recognizes and is capable of transforming values of the tts:fontSize attribute that consist of a single <length> specification.

A TT AF presentation processor supports the #fontSize-isomorphic feature if it implements presentation semantic support for defined values of the tts:fontSize attribute that consist of a single <length> specification.

E.1.38 E.1.47 #fontStyle

A TT AF transformation processor supports the #fontStyle feature if it recognizes and is capable of transforming all defined values of the tts:fontStyle attribute.

A TT AF presentation processor supports the #fontStyle feature if it implements presentation semantic support for all defined values of the tts:fontStyle attribute.

E.1.39 E.1.48 #fontStyle-italic

A TT AF transformation processor supports the #fontStyle-italic feature if it recognizes and is capable of transforming the italic value of the tts:fontStyle attribute.

A TT AF presentation processor supports the #fontStyle-italic feature if it implements presentation semantic support for the italic of the tts:fontStyle attribute.

E.1.49 #fontStyle-oblique

A TT AF transformation processor supports the #fontStyle-oblique feature if it recognizes and is capable of transforming the oblique value of the tts:fontStyle attribute.

A TT AF presentation processor supports the #fontStyle-oblique feature if it implements presentation semantic support for the oblique of the tts:fontStyle attribute.

E.1.50 #fontStyle-reverseOblique

A TT AF transformation processor supports the #fontStyle-reverseOblique feature if it recognizes and is capable of transforming the reverseOblique value of the tts:fontStyle attribute.

A TT AF presentation processor supports the #fontStyle-reverseOblique feature if it implements presentation semantic support for the reverseOblique of the tts:fontStyle attribute.

E.1.40 E.1.51 #fontWeight

A TT AF transformation processor supports the #fontWeight feature if it recognizes and is capable of transforming all defined values of the tts:fontWeight attribute.

A TT AF presentation processor supports the #fontWeight feature if it implements presentation semantic support for all defined values of the tts:fontWeight attribute.

E.1.41 E.1.52 #fontWeight-bold

A TT AF transformation processor supports the #fontWeight-bold feature if it recognizes and is capable of transforming bold value of the tts:fontWeight attribute.

A TT AF presentation processor supports the #fontWeight-bold feature if it implements presentation semantic support for the bold of the tts:fontWeight attribute.

E.1.42 E.1.53 #frameRate

A TT AF transformation processor supports the #frameRate feature if it recognizes and is capable of transforming the ttp:frameRate attribute.

A TT AF presentation processor supports the #frameRate feature if it implements presentation semantic support for the ttp:frameRate attribute.

E.1.43 E.1.54 #frameRateMultiplier

A TT AF transformation processor supports the #frameRateMultiplier feature if it recognizes and is capable of transforming the ttp:frameRateMultiplier attribute.

A TT AF presentation processor supports the #frameRateMultiplier feature if it implements presentation semantic support for the ttp:frameRateMultiplier attribute.

E.1.44 E.1.55 #layout

A TT AF transformation processor supports the #layout feature if it (1) recognizes and is capable of transforming the following vocabulary defined by 9 Layout :

layout
region
@ region

and (2) supports the following attributes when applied to the region element:

tts:extent
tts:origin

A TT AF presentation processor supports the #layout feature if it implements presentation semantic support for the same vocabulary and features enumerated above.

E.1.45 E.1.56 #length

A TT AF transformation processor supports the #length feature if it recognizes and is capable of transforming all defined values of the <length> style value expression.

A TT AF presentation processor supports the #length feature if it implements presentation semantic support for all defined values of the <length> style value expression.

E.1.46 E.1.57 #length-cell

A TT AF transformation processor supports the #length-cell feature if it recognizes and is capable of transforming scalar values of the <length> style value expression that use c (cell) units.

A TT AF presentation processor supports the #length-cell feature if it implements presentation semantic support for scalar values of the <length> style value expression that use c (cell) units.

E.1.47 E.1.58 #length-em

A TT AF transformation processor supports the #length-em feature if it recognizes and is capable of transforming scalar values of the <length> style value expression that use em (EM) units.

A TT AF presentation processor supports the #length-em feature if it implements presentation semantic support for scalar values of the <length> style value expression that use em (EM) units.

E.1.48 E.1.59 #length-integer

A TT AF transformation processor supports the #length-integer feature if it recognizes and is capable of transforming integer values of the <length> style value expression.

A TT AF presentation processor supports the #length-integer feature if it implements presentation semantic support for integer values of the <length> style value expression.

E.1.49 E.1.60 #length-negative

A TT AF transformation processor supports the #length-negative feature if it recognizes and is capable of transforming negative values of the <length> style value expression.

A TT AF presentation processor supports the #length-negative feature if it implements presentation semantic support for negative values of the <length> style value expression.

E.1.50 E.1.61 #length-percentage

A TT AF transformation processor supports the #length-percentage feature if it recognizes and is capable of transforming percentage values of the <length> style value expression.

A TT AF presentation processor supports the #length-percentage feature if it implements presentation semantic support for percentage values of the <length> style value expression.

E.1.51 E.1.62 #length-pixel

A TT AF transformation processor supports the #length-pixel feature if it recognizes and is capable of transforming scalar values of the <length> style value expression that use px (pixel) units.

A TT AF presentation processor supports the #length-pixel feature if it implements presentation semantic support for scalar values of the <length> style value expression that use px (pixel) units.

E.1.52 E.1.63 #length-positive

A TT AF transformation processor supports the #length-positive feature if it recognizes and is capable of transforming positive values of the <length> style value expression.

A TT AF presentation processor supports the #length-positive feature if it implements presentation semantic support for positive values of the <length> style value expression.

E.1.53 E.1.64 #length-real

A TT AF transformation processor supports the #length-real feature if it recognizes and is capable of transforming real values of the <length> style value expression.

A TT AF presentation processor supports the #length-real feature if it implements presentation semantic support for real values of the <length> style value expression.

E.1.54 E.1.65 #lineBreak-uax14

A TT AF transformation processor supports the #lineBreak-uax14 feature if it recognizes and is capable of transforming requirements expressed by [UAX14] into its target document space.

A TT AF presentation processor supports the #lineBreak-uax14 feature if it implements presentation semantic support for [UAX14] as applies to line breaking.

E.1.55 E.1.66 #lineHeight

A TT AF transformation processor supports the #lineHeight feature if it recognizes and is capable of transforming the tts:lineHeight attribute.

A TT AF presentation processor supports the #lineHeight feature if it implements presentation semantic support for the tts:lineHeight attribute.

E.1.56 E.1.67 #markerMode

A TT AF transformation processor supports the #markerMode feature if it recognizes and is capable of transforming the ttp:markerMode attribute.

A TT AF presentation processor supports the #markerMode feature if it implements presentation semantic support for the ttp:markerMode attribute.

E.1.68 #markerMode-continuous

A TT AF transformation processor supports the #markerMode-continuous feature if it recognizes and is capable of transforming the continuous value of the ttp:markerMode attribute.

A TT AF presentation processor supports the #markerMode-continuous feature if it implements presentation semantic support for the continuous value of the ttp:markerMode attribute.

E.1.69 #markerMode-discontinuous

A TT AF transformation processor supports the #markerMode-discontinuous feature if it recognizes and is capable of transforming the discontinuous value of the ttp:markerMode attribute.

A TT AF presentation processor supports the #markerMode-discontinuous feature if it implements presentation semantic support for the discontinuous value of the ttp:markerMode attribute.

E.1.57 E.1.70 #metadata

A TT AF transformation processor supports the #metadata feature if it recognizes and is capable of transforming the following vocabulary defined by 12 Metadata :

metadata
ttm:title
ttm:desc
ttm:copyright
ttm:agent
ttm:name
ttm:actor
@ ttm:agent
@ ttm:role

A TT AF presentation processor supports the #metadata feature if it recognizes and is capable of presenting the information expressed by the same vocabulary enumerated above.

Note:

This specification does not define a standardized form for the presentation of metadata information. The presentation or ability to present metadata information is considered to be implementation dependent.

E.1.58 E.1.71 #nested-div

A TT AF transformation processor supports the #nested-div feature if it recognizes and is capable of transforming nested div elements.

A TT AF presentation processor supports the #nested-div feature if it implements presentation semantic support for nested div elements.

E.1.59 E.1.72 #nested-span

A TT AF transformation processor supports the #nested-span feature if it recognizes and is capable of transforming nested span elements.

A TT AF presentation processor supports the #nested-span feature if it implements presentation semantic support for nested span elements.

E.1.60 E.1.73 #opacity

A TT AF transformation processor supports the #opacity feature if it recognizes and is capable of transforming the tts:opacity attribute.

A TT AF presentation processor supports the #opacity feature if it (1) implements presentation semantic support for the tts:opacity attribute and (2) is capable of displaying or generating an output display signal that distinguishes between at least eight (8) values of opacity.

E.1.61 E.1.74 #origin

A TT AF transformation processor supports the #origin feature if it recognizes and is capable of transforming the tts:origin attribute.

A TT AF presentation processor supports the #origin feature if it implements presentation semantic support for the tts:origin attribute.

E.1.62 E.1.75 #overflow

A TT AF transformation processor supports the #overflow feature if it recognizes and is capable of transforming all defined values of the tts:overflow attribute.

A TT AF presentation processor supports the #overflow feature if it implements presentation semantic support for all defined values of the tts:overflow attribute.

E.1.63 E.1.76 #overflow-dynamic

A TT AF transformation processor supports the #overflow-dynamic feature if it recognizes and is capable of transforming the dynamic value of the tts:overflow attribute.

A TT AF presentation processor supports the #overflow-dynamic feature if it implements presentation semantic support for the dynamic value of the tts:overflow attribute.

E.1.77 #overflow-visible

A TT AF transformation processor supports the #overflow-visible feature if it recognizes and is capable of transforming the visible value of the tts:overflow attribute.

A TT AF presentation processor supports the #overflow-visible feature if it implements presentation semantic support for the visible value of the tts:overflow attribute.

E.1.64 E.1.78 #padding

A TT AF transformation processor supports the #padding feature if it recognizes and is capable of transforming the tts:padding attribute.

A TT AF presentation processor supports the #padding feature if it implements presentation semantic support for the tts:padding attribute.

E.1.65 E.1.79 #padding-1

A TT AF transformation processor supports the #padding-1 feature if it recognizes and is capable of transforming values of the tts:padding attribute that consist of one <length> specification.

A TT AF presentation processor supports the #padding-1 feature if it implements presentation semantic support for values of the tts:padding attribute that consist of one <length> specification.

E.1.66 E.1.80 #padding-2

A TT AF transformation processor supports the #padding-2 feature if it recognizes and is capable of transforming values of the tts:padding attribute that consist of two <length> specification.

A TT AF presentation processor supports the #padding-2 feature if it implements presentation semantic support for values of the tts:padding attribute that consist of two <length> specification.

E.1.67 E.1.81 #padding-3

A TT AF transformation processor supports the #padding-3 feature if it recognizes and is capable of transforming values of the tts:padding attribute that consist of three <length> specification.

A TT AF presentation processor supports the #padding-3 feature if it implements presentation semantic support for values of the tts:padding attribute that consist of three <length> specification.

E.1.68 E.1.82 #padding-4

A TT AF transformation processor supports the #padding-4 feature if it recognizes and is capable of transforming values of the tts:padding attribute that consist of four <length> specification.

A TT AF presentation processor supports the #padding-4 feature if it implements presentation semantic support for values of the tts:padding attribute that consist of four <length> specification.

E.1.69 E.1.83 #pixelAspectRatio

A TT AF transformation processor supports the #pixelAspectRatio feature if it recognizes and is capable of transforming the ttp:pixelAspectRatio attribute.

A TT AF presentation processor supports the #pixelAspectRatio feature if it implements presentation semantic support for the ttp:pixelAspectRatio attribute.

E.1.70 E.1.84 #presentation

A TT AF processor supports the #presentation feature if it (1) satisfies the generic processor criteria defined by 3.2.1 Generic Processor Conformance , (2) implements support for the region and line layout semantics defined by 9.3 Region Layout and Presentation and 9.4 Line Layout , respectively, and (3) implements presentation semantics for the following features:

#content
#core
#profile
#structure
#time-offset
#timing

In addition, a TT AF processor that supports the #presentation feature should satisfy the user agent accessibility guidelines specified by [UAAG] .

E.1.71 E.1.85 #profile

A TT AF transformation processor supports the #profile feature if it recognizes and is capable of transforming the ttp:profile attribute on the tt element and transforming the following vocabulary defined by 6.1 Parameter Element Vocabulary :

ttp:profile
ttp:features
ttp:feature
ttp:extensions
ttp:extension

A TT AF presentation processor supports the #profile feature if it implements presentation semantic support for the same vocabulary specified above.

E.1.72 E.1.86 #rollUp

A TT AF processor supports the #rollUp feature if it supports the following features:

#layout
#overflow-dynamic
#dynamicFlow-rollUp

E.1.73 E.1.87 #showBackground

A TT AF transformation processor supports the #showBackground feature if it recognizes and is capable of transforming all defined values of the tts:showBackground attribute.

A TT AF presentation processor supports the #showBackground feature if it implements presentation semantic support for all defined values of the tts:showBackground attribute.

E.1.74 #smpteMode A TT AF transformation processor supports the #smpteMode feature if it recognizes and is capable of transforming the ttp:smpteMode attribute. A TT AF presentation processor supports the #smpteMode feature if it implements presentation semantic support for the ttp:smpteMode attribute. E.1.75 E.1.88 #structure

A TT AF transformation processor supports the #structure feature if it recognizes and is capable of transforming the following vocabulary defined by 7 Content :

tt
head

A TT AF presentation processor supports the #structure feature if it implements presentation semantic support for the same vocabulary enumerated above.

E.1.76 E.1.89 #styling

A TT AF transformation processor supports the #styling feature if it recognizes and is capable of transforming the following vocabulary defined by 8 Styling :

styling
style
@ style

A TT AF presentation processor supports the #styling feature if it implements presentation semantic support for the same vocabulary enumerated above.

E.1.77 E.1.90 #styling-chained

A TT AF transformation processor supports the #styling-chained feature if it recognizes and is capable of transforming chained style association as defined by 8.4.1.3 Chained Referential Styling .

A TT AF presentation processor supports the #styling-chained feature if it implements presentation semantic support for chained style association as defined by 8.4.1.3 Chained Referential Styling .

E.1.78 E.1.91 #styling-inheritance-content

A TT AF transformation processor supports the #styling-inheritance feature if it recognizes and is capable of transforming content style inheritance as defined by 8.4.2.1 Content Style Inheritance .

A TT AF presentation processor supports the #styling-inheritance-content feature if it implements presentation semantic support for content style inheritance as defined by 8.4.2.1 Content Style Inheritance .

E.1.79 E.1.92 #styling-inheritance-region

A TT AF transformation processor supports the #styling-inheritance feature if it recognizes and is capable of transforming region style inheritance as defined by 8.4.2.2 Region Style Inheritance .

A TT AF presentation processor supports the #styling-inheritance-region feature if it implements presentation semantic support for region style inheritance as defined by 8.4.2.2 Region Style Inheritance .

E.1.80 E.1.93 #styling-inline

A TT AF transformation processor supports the #styling-inline feature if it recognizes and is capable of transforming inline style association as defined by 8.4.1.1 Inline Styling .

A TT AF presentation processor supports the #styling-inline feature if it implements presentation semantic support for inline style association as defined by 8.4.1.1 Inline Styling .

E.1.81 E.1.94 #styling-nested

A TT AF transformation processor supports the #styling-nested feature if it recognizes and is capable of transforming nested style association as defined by 8.4.1.4 Nested Styling .

A TT AF presentation processor supports the #styling-nested feature if it implements presentation semantic support for nested style association as defined by 8.4.1.4 Nested Styling .

E.1.82 E.1.95 #styling-referential

A TT AF transformation processor supports the #styling-referential feature if it recognizes and is capable of transforming referential style association as defined by 8.4.1.2 Referential Styling .

A TT AF presentation processor supports the #styling-referential feature if it implements presentation semantic support for referential style association as defined by 8.4.1.2 Referential Styling .

E.1.83 E.1.96 #subFrameRate

A TT AF transformation processor supports the #subFrameRate feature if it recognizes and is capable of transforming the ttp:subFrameRate attribute.

A TT AF presentation processor supports the #subFrameRate feature if it implements presentation semantic support for the ttp:subFrameRate attribute.

E.1.84 E.1.97 #textAlign

A TT AF transformation processor supports the #textAlign feature if it recognizes and is capable of transforming all defined values of the tts:textAlign attribute.

A TT AF presentation processor supports the #textAlign feature if it implements presentation semantic support for all defined values of the tts:textAlign attribute.

E.1.85 E.1.98 #textAlign-absolute

A TT AF transformation processor supports the #textAlign-absolute feature if it recognizes and is capable of transforming the left , center , and right values of the tts:textAlign attribute.

A TT AF presentation processor supports the #textAlign-absolute feature if it implements presentation semantic support for the left , center , and right values of the tts:textAlign attribute.

E.1.86 E.1.99 #textAlign-relative

A TT AF transformation processor supports the #textAlign-relative feature if it recognizes and is capable of transforming the start , center , and end values of the tts:textAlign attribute.

A TT AF presentation processor supports the #textAlign-relative feature if it implements presentation semantic support for the start , center , and end values of the tts:textAlign attribute.

E.1.87 E.1.100 #textDecoration

A TT AF transformation processor supports the #textDecoration feature if it recognizes and is capable of transforming all defined values of the tts:textDecoration attribute.

A TT AF presentation processor supports the #textDecoration feature if it implements presentation semantic support for all defined values of the tts:textDecoration attribute.

E.1.88 E.1.101 #textDecoration-over

A TT AF transformation processor supports the #textDecoration-over feature if it recognizes and is capable of transforming the overline and noOverline values of the tts:textDecoration attribute.

A TT AF presentation processor supports the #textDecoration-over feature if it implements presentation semantic support for the overline and noOverline values of the tts:textDecoration attribute.

E.1.89 E.1.102 #textDecoration-through

A TT AF transformation processor supports the #textDecoration-through feature if it recognizes and is capable of transforming the lineThrough and noLineThrough values of the tts:textDecoration attribute.

A TT AF presentation processor supports the #textDecoration-through feature if it implements presentation semantic support for the lineThrough and noLineThrough values of the tts:textDecoration attribute.

E.1.90 E.1.103 #textDecoration-under

A TT AF transformation processor supports the #textDecoration-under feature if it recognizes and is capable of transforming the underline and noUnderline values of the tts:textDecoration attribute.

A TT AF presentation processor supports the #textDecoration-under feature if it implements presentation semantic support for the underline and noUnderline values of the tts:textDecoration attribute.

E.1.91 E.1.104 #textOutline

A TT AF transformation processor supports the #textOutline feature if it recognizes and is capable of transforming the tts:textOutline attribute.

A TT AF presentation processor supports the #textOutline feature if it implements presentation semantic support for the tts:textOutline attribute.

E.1.92 #textOutline-blur E.1.105 #textOutline-blurred

A TT AF transformation processor supports the #textOutline-blur #textOutline-blurred feature if it recognizes and is capable of transforming values of the tts:textOutline attribute that includes a blur radius specification.

A TT AF presentation processor supports the #textOutline-blurred feature if it implements presentation semantic support for values of the tts:textOutline attribute that includes a blur radius specification.

E.1.106 #textOutline-unblurred

A TT AF transformation processor supports the #textOutline-unblurred feature if it recognizes and is capable of transforming values of the tts:textOutline attribute that does not include a blur radius specification.

A TT AF presentation processor supports the #textOutline-blur #textOutline-unblurred feature if it implements presentation semantic support for values of the tts:textOutline attribute that does not include a blur radius specification.

E.1.93 E.1.107 #tickRate

A TT AF transformation processor supports the #tickRate feature if it recognizes and is capable of transforming the ttp:tickRate attribute.

A TT AF presentation processor supports the #tickRate feature if it implements presentation semantic support for the ttp:tickRate attribute.

E.1.94 E.1.108 #timeBase-clock

A TT AF transformation processor supports the #timeBase-clock feature if it recognizes and is capable of transforming the clock value of the ttp:timeBase attribute and if it supports the #clockMode feature.

A TT AF presentation processor supports the #timeBase-clock feature if it implements presentation semantic support for the clock value of the ttp:timeBase attribute and if it supports the #clockMode feature.

E.1.95 E.1.109 #timeBase-media

A TT AF transformation processor supports the #timeBase-media feature if it recognizes and is capable of transforming the media value of the ttp:timeBase attribute.

A TT AF presentation processor supports the #timeBase-media feature if it implements presentation semantic support for the media value of the ttp:timeBase attribute.

E.1.96 E.1.110 #timeBase-smpte

A TT AF transformation processor supports the #timeBase-smpte feature if it recognizes and is capable of transforming the smpte value of the ttp:timeBase attribute and if it supports the #smpteMode # dropMode feature.

A TT AF presentation processor supports the #timeBase-smpte feature if it implements presentation semantic support for the smpte value of the ttp:timeBase attribute and if it supports the #smpteMode # dropMode feature.

E.1.97 E.1.111 #timeContainer

A TT AF transformation processor supports the #timeContainer feature if it recognizes and is capable of transforming the timeContainer attribute.

A TT AF presentation processor supports the #timeContainer feature if it implements presentation semantic support for the timeContainer attribute.

E.1.98 E.1.112 #time-clock

A TT AF transformation processor supports the #time-clock feature if it recognizes and is capable of transforming all values of the <timeExpression> that satisfy the following subset of time expression syntax:

<timeExpression>
  : hours ":" minutes ":" seconds ( fraction )?

A TT AF presentation processor supports the #time-clock feature if it implements presentation semantic support for the same syntax specified above.

E.1.99 E.1.113 #time-clock-with-frames

A TT AF transformation processor supports the #time-clock-with-frames feature if it supports the #frameRate , #frameRateMultiplier , and #subFrameRate features and if it recognizes and is capable of transforming all values of the <timeExpression> that satisfy the following subset of time expression syntax:

<timeExpression>
  : hours ":" minutes ":" seconds ( fraction | ":" frames ( "." sub-frames )? )?

A TT AF presentation processor supports the #time-clock-with-frames feature if it implements presentation semantic support for the same features and syntax specified above.

E.1.100 E.1.114 #time-offset

A TT AF transformation processor supports the #time-offset feature if it recognizes and is capable of transforming all values of the <timeExpression> that satisfy the following subset of time expression syntax:

<timeExpression>
  : time-count fraction? ( "h" | "m" | "s" | "ms" )

A TT AF presentation processor supports the #time-offset feature if it implements presentation semantic support for the same syntax specified above.

E.1.101 E.1.115 #time-offset-with-frames

A TT AF transformation processor supports the #time-offset-with-frames feature if it supports the #frameRate , #frameRateMultiplier , and #subFrameRate features and if it recognizes and is capable of transforming all values of the <timeExpression> that satisfy the following subset of time expression syntax:

<timeExpression>
  : time-count fraction? "f"

A TT AF presentation processor supports the #time-offset-with-frames feature if it implements presentation semantic support for the same features and syntax specified above.

E.1.102 E.1.116 #time-offset-with-ticks

A TT AF transformation processor supports the #time-offset-with-ticks feature if it supports the #tickRate feature and if it recognizes and is capable of transforming all values of the <timeExpression> that satisfy the following subset of time expression syntax:

<timeExpression>
  : time-count fraction? "t"

A TT AF presentation processor supports the #time-offset-with-ticks feature if it implements presentation semantic support for the same features and syntax specified above.

E.1.103 E.1.117 #timing

A TT AF transformation processor supports the #timing feature if it recognizes and is capable of transforming the following vocabulary defined by 10 Timing :

@ begin
@ dur
@ end

A TT AF presentation processor supports the #timing feature if it implements presentation semantic support for the same vocabulary enumerated above.

E.1.104 E.1.118 #transformation

A TT AF processor supports the #transformation feature if it (1) satisfies the generic processor criteria defined by 3.2.1 Generic Processor Conformance and (2) implements transformation semantics for the following features:

#content
#core
#profile
#structure
#time-offset
#timing

E.1.105 E.1.119 #unicodeBidi

A TT AF transformation processor supports the #unicodeBidi feature if it recognizes and is capable of transforming all defined values of the tts:unicodeBidi attribute.

A TT AF presentation processor supports the #unicodeBidi feature if it implements presentation semantic support for all defined values of the tts:unicodeBidi attribute.

E.1.106 E.1.120 #visibility

A TT AF transformation processor supports the #visibility feature if it recognizes and is capable of transforming all defined values of the tts:visibility attribute.

A TT AF presentation processor supports the #visibility feature if it implements presentation semantic support for all defined values of the tts:visibility attribute.

E.1.107 E.1.121 #visibility-block

A TT AF transformation processor supports the #visibility-block feature if it recognizes and is capable of transforming all defined values of the tts:visibility attribute when applied to a content element that would generate a block area during presentation processing.

A TT AF presentation processor supports the #visibility-block feature if it implements presentation semantic support for all defined values of the tts:visibility attribute when applied to a content element that generates a block area.

E.1.108 E.1.122 #visibility-inline

A TT AF transformation processor supports the #visibility-inline feature if it recognizes and is capable of transforming all defined values of the tts:visibility attribute when applied to a content element that would generate an inline area during presentation processing.

A TT AF presentation processor supports the #visibility-inline feature if it implements presentation semantic support for all defined values of the tts:visibility attribute when applied to a content element that generates an inline area.

E.1.109 E.1.123 #visibility-region

A TT AF transformation processor supports the #visibility-region feature if it recognizes and is capable of transforming all defined values of the tts:visibility attribute when applied to a region element.

A TT AF presentation processor supports the #visibility-region feature if it implements presentation semantic support for all defined values of the tts:visibility attribute when applied to a region element.

E.1.110 E.1.124 #wrapOption

A TT AF transformation processor supports the #wrapOption feature if it recognizes and is capable of transforming all defined values of the tts:wrapOption attribute.

A TT AF presentation processor supports the #wrapOption feature if it implements presentation semantic support for all defined values of the tts:wrapOption attribute.

E.1.111 E.1.125 #writingMode

A TT AF transformation processor supports the #writingMode feature if it recognizes and is capable of transforming all defined values of the tts:writingMode attribute.

A TT AF presentation processor supports the #writingMode feature if it implements presentation semantic support for all defined values of the tts:writingMode attribute.

E.1.112 E.1.126 #writingMode-vertical

A TT AF transformation processor supports the #writingMode-vertical feature if it recognizes and is capable of transforming the tbrl , tblr , and tb values of the tts:writingMode attribute.

A TT AF presentation processor supports the #writingMode-vertical feature if it implements presentation semantic support for the tbrl , tblr , and tb values of the tts:writingMode attribute.

E.1.113 E.1.127 #writingMode-horizontal

A TT AF transformation processor supports the #writingMode-horizontal feature if it recognizes and is capable of transforming the lrtb , rltb , lr and rl values of the tts:writingMode attribute.

A TT AF presentation processor supports the #writingMode-horizontal feature if it implements presentation semantic support for the lrtb , rltb , lr and rl values of the tts:writingMode attribute.

E.1.114 E.1.128 #writingMode-horizontal-lr

A TT AF transformation processor supports the #writingMode-horizontal feature if it recognizes and is capable of transforming the lrtb and lr values of the tts:writingMode attribute.

A TT AF presentation processor supports the #writingMode-horizontal-lr feature if it implements presentation semantic support for the lrtb and lr values of the tts:writingMode attribute.

E.1.115 E.1.129 #writingMode-horizontal-rl

A TT AF transformation processor supports the #writingMode-horizontal feature if it recognizes and is capable of transforming the rltb and rl values of the tts:writingMode attribute.

A TT AF presentation processor supports the #writingMode-horizontal-rl feature if it implements presentation semantic support for the rltb and rl values of the tts:writingMode attribute.

E.1.116 E.1.130 #zIndex

A TT AF transformation processor supports the #zIndex feature if it recognizes and is capable of transforming the tts:zIndex attribute.

A TT AF presentation processor supports the #zIndex feature if it implements presentation semantic support for the tts:zIndex attribute.

E.2 Feature Support

The following table, Table E-1 – Feature Support , enumerates every defined feature designation (expressed without the TT Feature Namespace), and, for each designated feature, specifies whether the feature is mandatory (M) or optional (O) for transformation and presentation processors.

Table E-1 – Feature Support
Feature	Transformation	Presentation
`#animation`	O	O
`#backgroundColor`	O	O
`#backgroundColor-block`	O	O
`#backgroundColor-inline`	O	O
`#backgroundColor-region`	O	O
`#bidi`	O	O
`#cellResolution`	O	O
`#clockMode`	O	O
`#clockMode-gps`	O	O
`#clockMode-local`	O	O
`#clockMode-utc`	O	O
`#color`	O	O
`#content`	M	M
`#core`	M	M
`#direction`	O	O
`#display`	O	O
`#display-block`	O	O
`#display-inline`	O	O
`#display-region`	O	O
`#displayAlign`	O	O
`# dropMode`	O	O
`#dropMode-dropNTSC`	O	O
`#dropMode-dropPAL`	O	O
`#dropMode-nonDrop`	O	O
`#dynamicFlow`	O	O
`#dynamicFlow-character`	O	O
`#dynamicFlow-clear`	O	O
`#dynamicFlow-fill`	O	O
`#dynamicFlow-glyph`	O	O
`#dynamicFlow-in`	O	O
`#dynamicFlow-jump`	O	O
`#dynamicFlow-line`	O	O
`#dynamicFlow-out`	O	O
`#dynamicFlow-rollUp`	O	O
`#dynamicFlow-smooth`	O	O
`#dynamicFlow-teletext`	O	O
`#dynamicFlow-word`	O	O
`#extent`	O	O
`#extent-region`	O	O
`#extent-root`	O	O
`#fontFamily`	O	O
`#fontFamily-generic`	O	O
`#fontFamily-non-generic`	O	O
`#fontSize`	O	O
`#fontSize-anisomorphic #fontSize- anamorphic`	O	O
`#fontSize-isomorphic`	O	O
`#fontStyle`	O	O
`#fontStyle-italic`	O	O
`#fontStyle-oblique`	O	O
`#fontStyle-reverseOblique`	O	O
`#fontWeight`	O	O
`#fontWeight-bold`	O	O
`#frameRate`	O	O
`#frameRateMultiplier`	O	O
`#layout`	O	O
`#length`	O	O
`#length-cell`	O	O
`#length-em`	O	O
`#length-integer`	O	O
`#length-negative`	O	O
`#length-percentage`	O	O
`#length-pixel`	O	O
`#length-positive`	O	O
`#length-real`	O	O
`#lineBreak-uax14`	O	O
`#lineHeight`	O	O
`#markerMode`	O	O
`#markerMode-continuous`	O	O
`#markerMode-discontinuous`	O	O
`#metadata`	O	O
`#nested-div`	O	O
`#nested-span`	O	O
`#opacity`	O	O
`#origin`	O	O
`#overflow`	O	O
`#overflow-dynamic`	O	O
`#overflow-visible`	O	O
`#padding`	O	O
`#padding-1`	O	O
`#padding-2`	O	O
`#padding-3`	O	O
`#padding-4`	O	O
`#pixelAspectRatio`	O	O
`#presentation`	O	M
`#profile`	M	M
`#rollUp`	O	O
`#showBackground`	O	O
~~#smpteMode O O~~ `#structure`	M	M
`#styling`	O	O
`#styling-chained`	O	O
`#styling-inheritance-content`	O	O
`#styling-inheritance-region`	O	O
`#styling-inline`	O	O
`#styling-nested`	O	O
`#styling-referential`	O	O
`#subFrameRate`	O	O
`#textAlign`	O	O
`#textAlign-absolute`	O	O
`#textAlign-relative`	O	O
`#textDecoration`	O	O
`#textDecoration-over`	O	O
`#textDecoration-through`	O	O
`#textDecoration-under`	O	O
`#textOutline`	O	O
`#textOutline-blur #textOutline-blurred`	O	O
`#textOutline-unblurred`	O	O
`#tickRate`	O	O
`#timeBase-clock`	O	O
`#timeBase-media`	O	O
`#timeBase-smpte`	O	O
`#timeContainer`	O	O
`#time-clock`	O	O
`#time-clock-with-frames`	O	O
`#time-offset`	M	M
`#time-offset-with-frames`	O	O
`#time-offset-with-ticks`	O	O
`#timing`	M	M
`#transformation`	M	O
`#unicodeBidi`	O	O
`#visibility`	O	O
`#visibility-block`	O	O
`#visibility-inline`	O	O
`#visibility-region`	O	O
`#wrapOption`	O	O
`#writingMode`	O	O
`#writingMode-vertical`	O	O
`#writingMode-horizontal`	O	O
`#writingMode-horizontal-lr`	O	O
`#writingMode-horizontal-rl`	O	O
`#zIndex`	O	O

For the sake of convenience, the following table, Table E-2 – Mandatory Features - Transformation , enumerates all mandatory features for a TT AF Transformation Processor, providing additional comments to summarize the context of usage or the nature of the feature. The TT AF Profile Definition Document that defines the corresponding DFXP Transformation Profile is specified in G.1 DFXP Transformation Profile .

Table E-2 – Mandatory Features - Transformation
Feature	Comments
`#content`	`body` , `div` , `p` , `span` , `br`
`#core`	@ `xml:id` , @ `xml:lang` , @ `xml:space`
`#profile`
`#structure`	`tt` , `head`
`#time-offset`
`#timing`	@ `begin` , @ `dur` , @ `end`
`#transformation`

For the sake of convenience, the following table, Table E-3 – Mandatory Features - Presentation , enumerates all mandatory features for a TT AF Presentation Processor, providing additional comments to summarize the context of usage or the nature of the feature. The TT AF Profile Definition Document that defines the corresponding DFXP Presentation Profile is specified in G.2 DFXP Presentation Profile .

Table E-3 – Mandatory Features - Presentation
Feature	Comments
`#content`	`body` , `div` , `p` , `span` , `br`
`#core`	@ `xml:id` , @ `xml:lang` , @ `xml:space`
`#profile`
`#presentation`
`#structure`	`tt` , `head`
`#time-offset`
`#timing`	@ `begin` , @ `dur` , @ `end`

F Extensions

This appendix is normative.

This appendix specifies the syntactic form of extension designations, which are used to express authorial intent regarding the support for extension mechanisms in a TT AF processor.

F.1 Extension Designations

An extension designation is expressed as a string that adheres to the following form:

extension-designation
  : extension-namespace designation
extension-namespace
  :                   // http://www.w3.org/2006/10/ttaf1/extension

  : TT Extension Namespace                  // http://www.w3.org/2006/10/ttaf1/extension/

  | Other Extension Namespace               // expressed as an absolute URI
designation
  : "#" token-char+
token-char
  : { XML NameChar }                        // XML 1.1 Production [4a]

If the extension namespace of an extension designation is the TT Extension Namespace, then all values of the following designation token are reserved for future standardization.

If the extension namespace of an extension designation is not the TT Extension Namespace, i.e., is an Other Extension Namespace , then the extension namespace must be expressed as an absolute URI capable of serving as a base URI used in combination with a designation token that takes the form of a fragment identifier.

G Profiles

This appendix is normative.

This appendix specifies the following standard TT AF profiles:

G.1 DFXP Transformation Profile
G.2 DFXP Presentation Profile
G.3 DFXP Full Profile

Each TT AF profile is defined in terms of a TT AF Profile Definition Document, which is expressed as an XML document wherein the root element adheres to 6.1.1 ttp:profile .

G.1 DFXP Transformation Profile

The DFXP Transformation Profile is intended to be used to express minimum compliance for transformation processing.

<?xml version="1.0" encoding="utf-8"?>
<!-- this file defines the "dfxp-transformation" profile of ttaf1 -->
<profile xmlns="http://www.w3.org/2006/10/ttaf1#parameter">
<features xml:base="http://www.w3.org/2006/10/ttaf1/feature">

<features xml:base="http://www.w3.org/2006/10/ttaf1/feature/">

<!-- required (mandatory) feature support -->
<feature value="required">#content</feature>
<feature value="required">#core</feature>
<feature value="required">#profile</feature>
<feature value="required">#structure</feature>
<feature value="required">#time-offset</feature>
<feature value="required">#timing</feature>
<feature value="required">#transformation</feature>
<!-- optional (voluntary) feature support -->
<feature value="optional">#animation</feature>
<feature value="optional">#backgroundColor-block</feature>
<feature value="optional">#backgroundColor-inline</feature>
<feature value="optional">#backgroundColor-region</feature>
<feature value="optional">#backgroundColor</feature>
<feature value="optional">#bidi</feature>
<feature value="optional">#cellResolution</feature>
<feature value="optional">#clockMode-gps</feature>
<feature value="optional">#clockMode-local</feature>
<feature value="optional">#clockMode-utc</feature>

<feature value="optional">#clockMode</feature>
<feature value="optional">#color</feature>
<feature value="optional">#direction</feature>
<feature value="optional">#display-block</feature>
<feature value="optional">#display-inline</feature>
<feature value="optional">#display-region</feature>
<feature value="optional">#display</feature>
<feature value="optional">#displayAlign</feature>
<feature value="optional">#dropMode-dropNTSC</feature>
<feature value="optional">#dropMode-dropPAL</feature>
<feature value="optional">#dropMode-nonDrop</feature>
<feature value="optional">#dropMode</feature>

<feature value="optional">#dynamicFlow-character</feature>
<feature value="optional">#dynamicFlow-clear</feature>
<feature value="optional">#dynamicFlow-fill</feature>
<feature value="optional">#dynamicFlow-glyph</feature>
<feature value="optional">#dynamicFlow-in</feature>
<feature value="optional">#dynamicFlow-jump</feature>
<feature value="optional">#dynamicFlow-line</feature>
<feature value="optional">#dynamicFlow-out</feature>
<feature value="optional">#dynamicFlow-rollUp</feature>
<feature value="optional">#dynamicFlow-smooth</feature>
<feature value="optional">#dynamicFlow-teletext</feature>
<feature value="optional">#dynamicFlow-word</feature>
<feature value="optional">#dynamicFlow</feature>
<feature value="optional">#extent-region</feature>
<feature value="optional">#extent-root</feature>

<feature value="optional">#extent</feature>
<feature value="optional">#fontFamily-generic</feature>
<feature value="optional">#fontFamily-non-generic</feature>
<feature value="optional">#fontFamily</feature>
<feature value="optional">#fontSize-anisomorphic</feature>

<feature value="optional">#fontSize-anamorphic</feature>

<feature value="optional">#fontSize-isomorphic</feature>
<feature value="optional">#fontSize</feature>
<feature value="optional">#fontStyle-italic</feature>
<feature value="optional">#fontStyle-oblique</feature>
<feature value="optional">#fontStyle-reverseOblique</feature>

<feature value="optional">#fontStyle</feature>
<feature value="optional">#fontWeight-bold</feature>
<feature value="optional">#fontWeight</feature>
<feature value="optional">#frameRate</feature>
<feature value="optional">#frameRateMultiplier</feature>
<feature value="optional">#layout</feature>
<feature value="optional">#length-cell</feature>
<feature value="optional">#length-em</feature>
<feature value="optional">#length-negative</feature>
<feature value="optional">#length-percentage</feature>
<feature value="optional">#length-pixel</feature>
<feature value="optional">#length-positive</feature>
<feature value="optional">#length-real</feature>
<feature value="optional">#length</feature>
<feature value="optional">#lineBreak-uax14</feature>
<feature value="optional">#lineHeight</feature>
<feature value="optional">#markerMode-continuous</feature>
<feature value="optional">#markerMode-discontinuous</feature>

<feature value="optional">#markerMode</feature>
<feature value="optional">#metadata-foreign</feature>

<feature value="optional">#metadata</feature>
<feature value="optional">#nested-div</feature>
<feature value="optional">#nested-span</feature>
<feature value="optional">#opacity</feature>
<feature value="optional">#origin</feature>
<feature value="optional">#overflow-scroll</feature>
<feature value="optional">#overflow-visible</feature>

<feature value="optional">#overflow</feature>
<feature value="optional">#padding-1</feature>
<feature value="optional">#padding-2</feature>
<feature value="optional">#padding-3</feature>
<feature value="optional">#padding-4</feature>
<feature value="optional">#padding</feature>
<feature value="optional">#pixelAspectRatio</feature>
<feature value="optional">#presentation</feature>
<feature value="optional">#rollUp</feature>
<feature value="optional">#showBackground</feature>
<feature value="optional">#smpteMode</feature>

<feature value="optional">#styling-chained</feature>
<feature value="optional">#styling-inheritance-content</feature>
<feature value="optional">#styling-inheritance-region</feature>
<feature value="optional">#styling-inline</feature>
<feature value="optional">#styling-nested</feature>
<feature value="optional">#styling-referential</feature>
<feature value="optional">#styling</feature>
<feature value="optional">#subFrameRate</feature>
<feature value="optional">#textAlign-absolute</feature>
<feature value="optional">#textAlign-relative</feature>
<feature value="optional">#textAlign</feature>
<feature value="optional">#textDecoration-over</feature>
<feature value="optional">#textDecoration-through</feature>
<feature value="optional">#textDecoration-under</feature>
<feature value="optional">#textDecoration</feature>
<feature value="optional">#textOutline-blur</feature>

<feature value="optional">#textOutline-blurred</feature>
<feature value="optional">#textOutline-unblurred</feature>

<feature value="optional">#textOutline</feature>
<feature value="optional">#tickRate</feature>
<feature value="optional">#time-clock-with-frames</feature>
<feature value="optional">#time-clock</feature>
<feature value="optional">#time-offset-with-frames</feature>
<feature value="optional">#time-offset-with-ticks</feature>
<feature value="optional">#timeBase-clock</feature>
<feature value="optional">#timeBase-media</feature>
<feature value="optional">#timeBase-smpte</feature>
<feature value="optional">#timeContainer</feature>
<feature value="optional">#unicodeBidi</feature>
<feature value="optional">#visibility-block</feature>
<feature value="optional">#visibility-inline</feature>
<feature value="optional">#visibility-region</feature>
<feature value="optional">#visibility</feature>
<feature value="optional">#wrapOption</feature>
<feature value="optional">#writingMode-horizontal-lr</feature>
<feature value="optional">#writingMode-horizontal-rl</feature>
<feature value="optional">#writingMode-horizontal</feature>
<feature value="optional">#writingMode-vertical</feature>
<feature value="optional">#writingMode</feature>
<feature value="optional">#zIndex</feature>
</features>
<extensions xml:base="http://www.w3.org/2006/10/ttaf1/extension">

<extensions xml:base="http://www.w3.org/2006/10/ttaf1/extension/">

<!-- required (mandatory) extension support -->
<!-- optional (voluntary) extension support -->
</extensions>
</profile>

G.2 DFXP Presentation Profile

The DFXP Presentation Profile is intended to be used to express minimum compliance for presentation processing.

<?xml version="1.0" encoding="utf-8"?>
<!-- this file defines the "dfxp-presentation" profile of ttaf1-dfxp -->
<profile xmlns="http://www.w3.org/2006/10/ttaf1#parameter">
<features xml:base="http://www.w3.org/2006/10/ttaf1/feature">

<features xml:base="http://www.w3.org/2006/10/ttaf1/feature/">

<!-- required (mandatory) feature support -->
<feature value="required">#content</feature>
<feature value="required">#core</feature>
<feature value="required">#presentation</feature>
<feature value="required">#profile</feature>
<feature value="required">#structure</feature>
<feature value="required">#time-offset</feature>
<feature value="required">#timing</feature>
<!-- optional (voluntary) feature support -->
<feature value="optional">#animation</feature>
<feature value="optional">#backgroundColor-block</feature>
<feature value="optional">#backgroundColor-inline</feature>
<feature value="optional">#backgroundColor-region</feature>
<feature value="optional">#backgroundColor</feature>
<feature value="optional">#bidi</feature>
<feature value="optional">#cellResolution</feature>
<feature value="optional">#clockMode-gps</feature>
<feature value="optional">#clockMode-local</feature>
<feature value="optional">#clockMode-utc</feature>

<feature value="optional">#clockMode</feature>
<feature value="optional">#color</feature>
<feature value="optional">#direction</feature>
<feature value="optional">#display-block</feature>
<feature value="optional">#display-inline</feature>
<feature value="optional">#display-region</feature>
<feature value="optional">#display</feature>
<feature value="optional">#displayAlign</feature>
<feature value="optional">#dropMode-dropNTSC</feature>
<feature value="optional">#dropMode-dropPAL</feature>
<feature value="optional">#dropMode-nonDrop</feature>
<feature value="optional">#dropMode</feature>

<feature value="optional">#dynamicFlow-character</feature>
<feature value="optional">#dynamicFlow-clear</feature>
<feature value="optional">#dynamicFlow-fill</feature>
<feature value="optional">#dynamicFlow-glyph</feature>
<feature value="optional">#dynamicFlow-in</feature>
<feature value="optional">#dynamicFlow-jump</feature>
<feature value="optional">#dynamicFlow-line</feature>
<feature value="optional">#dynamicFlow-out</feature>
<feature value="optional">#dynamicFlow-rollUp</feature>
<feature value="optional">#dynamicFlow-smooth</feature>
<feature value="optional">#dynamicFlow-teletext</feature>
<feature value="optional">#dynamicFlow-word</feature>
<feature value="optional">#dynamicFlow</feature>
<feature value="optional">#extent-region</feature>
<feature value="optional">#extent-root</feature>

<feature value="optional">#extent</feature>
<feature value="optional">#fontFamily-generic</feature>
<feature value="optional">#fontFamily-non-generic</feature>
<feature value="optional">#fontFamily</feature>
<feature value="optional">#fontSize-anisomorphic</feature>

<feature value="optional">#fontSize-anamorphic</feature>

<feature value="optional">#fontSize-isomorphic</feature>
<feature value="optional">#fontSize</feature>
<feature value="optional">#fontStyle-italic</feature>
<feature value="optional">#fontStyle-oblique</feature>
<feature value="optional">#fontStyle-reverseOblique</feature>

<feature value="optional">#fontStyle</feature>
<feature value="optional">#fontWeight-bold</feature>
<feature value="optional">#fontWeight</feature>
<feature value="optional">#frameRate</feature>
<feature value="optional">#frameRateMultiplier</feature>
<feature value="optional">#layout</feature>
<feature value="optional">#length-cell</feature>
<feature value="optional">#length-em</feature>
<feature value="optional">#length-negative</feature>
<feature value="optional">#length-percentage</feature>
<feature value="optional">#length-pixel</feature>
<feature value="optional">#length-positive</feature>
<feature value="optional">#length-real</feature>
<feature value="optional">#length</feature>
<feature value="optional">#lineBreak-uax14</feature>
<feature value="optional">#lineHeight</feature>
<feature value="optional">#markerMode-continuous</feature>
<feature value="optional">#markerMode-discontinuous</feature>

<feature value="optional">#markerMode</feature>
<feature value="optional">#metadata-foreign</feature>

<feature value="optional">#metadata</feature>
<feature value="optional">#nested-div</feature>
<feature value="optional">#nested-span</feature>
<feature value="optional">#opacity</feature>
<feature value="optional">#origin</feature>
<feature value="optional">#overflow-scroll</feature>
<feature value="optional">#overflow-visible</feature>

<feature value="optional">#overflow</feature>
<feature value="optional">#padding-1</feature>
<feature value="optional">#padding-2</feature>
<feature value="optional">#padding-3</feature>
<feature value="optional">#padding-4</feature>
<feature value="optional">#padding</feature>
<feature value="optional">#pixelAspectRatio</feature>
<feature value="optional">#rollUp</feature>
<feature value="optional">#showBackground</feature>
<feature value="optional">#smpteMode</feature>

<feature value="optional">#styling-chained</feature>
<feature value="optional">#styling-inheritance-content</feature>
<feature value="optional">#styling-inheritance-region</feature>
<feature value="optional">#styling-inline</feature>
<feature value="optional">#styling-nested</feature>
<feature value="optional">#styling-referential</feature>
<feature value="optional">#styling</feature>
<feature value="optional">#subFrameRate</feature>
<feature value="optional">#textAlign-absolute</feature>
<feature value="optional">#textAlign-relative</feature>
<feature value="optional">#textAlign</feature>
<feature value="optional">#textDecoration-over</feature>
<feature value="optional">#textDecoration-through</feature>
<feature value="optional">#textDecoration-under</feature>
<feature value="optional">#textDecoration</feature>
<feature value="optional">#textOutline-blur</feature>

<feature value="optional">#textOutline-blurred</feature>
<feature value="optional">#textOutline-unblurred</feature>

<feature value="optional">#textOutline</feature>
<feature value="optional">#tickRate</feature>
<feature value="optional">#time-clock-with-frames</feature>
<feature value="optional">#time-clock</feature>
<feature value="optional">#time-offset-with-frames</feature>
<feature value="optional">#time-offset-with-ticks</feature>
<feature value="optional">#timeBase-clock</feature>
<feature value="optional">#timeBase-media</feature>
<feature value="optional">#timeBase-smpte</feature>
<feature value="optional">#timeContainer</feature>
<feature value="optional">#transformation</feature>
<feature value="optional">#unicodeBidi</feature>
<feature value="optional">#visibility-block</feature>
<feature value="optional">#visibility-inline</feature>
<feature value="optional">#visibility-region</feature>
<feature value="optional">#visibility</feature>
<feature value="optional">#wrapOption</feature>
<feature value="optional">#writingMode-horizontal-lr</feature>
<feature value="optional">#writingMode-horizontal-rl</feature>
<feature value="optional">#writingMode-horizontal</feature>
<feature value="optional">#writingMode-vertical</feature>
<feature value="optional">#writingMode</feature>
<feature value="optional">#zIndex</feature>
</features>
<extensions xml:base="http://www.w3.org/2006/10/ttaf1/extension">

<extensions xml:base="http://www.w3.org/2006/10/ttaf1/extension/">

<!-- required (mandatory) extension support -->
<!-- optional (voluntary) extension support -->
</extensions>
</profile>

G.3 DFXP Full Profile

The DFXP Full Profile is intended to be used to express maximum compliance for both transformation and presentation processing.

<?xml version="1.0" encoding="utf-8"?>
<!-- this file defines the "dfxp-full" profile of ttaf1-dfxp -->
<profile xmlns="http://www.w3.org/2006/10/ttaf1#parameter">
<features xml:base="http://www.w3.org/2006/10/ttaf1/feature">

<features xml:base="http://www.w3.org/2006/10/ttaf1/feature/">

<!-- required (mandatory) feature support -->
<feature value="required">#animation</feature>
<feature value="required">#backgroundColor-block</feature>
<feature value="required">#backgroundColor-inline</feature>
<feature value="required">#backgroundColor-region</feature>
<feature value="required">#backgroundColor</feature>
<feature value="required">#bidi</feature>
<feature value="required">#cellResolution</feature>
<feature value="required">#clockMode-gps</feature>
<feature value="required">#clockMode-local</feature>
<feature value="required">#clockMode-utc</feature>

<feature value="required">#clockMode</feature>
<feature value="required">#color</feature>
<feature value="required">#content</feature>
<feature value="required">#core</feature>
<feature value="required">#direction</feature>
<feature value="required">#display-block</feature>
<feature value="required">#display-inline</feature>
<feature value="required">#display-region</feature>
<feature value="required">#display</feature>
<feature value="required">#displayAlign</feature>
<feature value="required">#dropMode-dropNTSC</feature>
<feature value="required">#dropMode-dropPAL</feature>
<feature value="required">#dropMode-nonDrop</feature>
<feature value="required">#dropMode</feature>

<feature value="required">#dynamicFlow-character</feature>
<feature value="required">#dynamicFlow-clear</feature>
<feature value="required">#dynamicFlow-fill</feature>
<feature value="required">#dynamicFlow-glyph</feature>
<feature value="required">#dynamicFlow-in</feature>
<feature value="required">#dynamicFlow-jump</feature>
<feature value="required">#dynamicFlow-line</feature>
<feature value="required">#dynamicFlow-out</feature>
<feature value="required">#dynamicFlow-rollUp</feature>
<feature value="required">#dynamicFlow-smooth</feature>
<feature value="required">#dynamicFlow-teletext</feature>
<feature value="required">#dynamicFlow-word</feature>
<feature value="required">#dynamicFlow</feature>
<feature value="required">#extent-region</feature>
<feature value="required">#extent-root</feature>

<feature value="required">#extent</feature>
<feature value="required">#fontFamily-generic</feature>
<feature value="required">#fontFamily-non-generic</feature>
<feature value="required">#fontFamily</feature>
<feature value="required">#fontSize-anisomorphic</feature>

<feature value="required">#fontSize-anamorphic</feature>

<feature value="required">#fontSize-isomorphic</feature>
<feature value="required">#fontSize</feature>
<feature value="required">#fontStyle-italic</feature>
<feature value="required">#fontStyle-oblique</feature>
<feature value="required">#fontStyle-reverseOblique</feature>

<feature value="required">#fontStyle</feature>
<feature value="required">#fontWeight-bold</feature>
<feature value="required">#fontWeight</feature>
<feature value="required">#frameRate</feature>
<feature value="required">#frameRateMultiplier</feature>
<feature value="required">#layout</feature>
<feature value="required">#length-cell</feature>
<feature value="required">#length-em</feature>
<feature value="required">#length-negative</feature>
<feature value="required">#length-percentage</feature>
<feature value="required">#length-pixel</feature>
<feature value="required">#length-positive</feature>
<feature value="required">#length-real</feature>
<feature value="required">#length</feature>
<feature value="required">#lineBreak-uax14</feature>
<feature value="required">#lineHeight</feature>
<feature value="required">#markerMode-continuous</feature>
<feature value="required">#markerMode-discontinuous</feature>

<feature value="required">#markerMode</feature>
<feature value="required">#metadata-foreign</feature>

<feature value="required">#metadata</feature>
<feature value="required">#nested-div</feature>
<feature value="required">#nested-span</feature>
<feature value="required">#opacity</feature>
<feature value="required">#origin</feature>
<feature value="required">#overflow-scroll</feature>
<feature value="required">#overflow-visible</feature>

<feature value="required">#overflow</feature>
<feature value="required">#padding-1</feature>
<feature value="required">#padding-2</feature>
<feature value="required">#padding-3</feature>
<feature value="required">#padding-4</feature>
<feature value="required">#padding</feature>
<feature value="required">#pixelAspectRatio</feature>
<feature value="required">#presentation</feature>
<feature value="required">#profile</feature>
<feature value="required">#rollUp</feature>
<feature value="required">#showBackground</feature>
<feature value="required">#smpteMode</feature>

<feature value="required">#structure</feature>
<feature value="required">#styling-chained</feature>
<feature value="required">#styling-inheritance-content</feature>
<feature value="required">#styling-inheritance-region</feature>
<feature value="required">#styling-inline</feature>
<feature value="required">#styling-nested</feature>
<feature value="required">#styling-referential</feature>
<feature value="required">#styling</feature>
<feature value="required">#subFrameRate</feature>
<feature value="required">#textAlign-absolute</feature>
<feature value="required">#textAlign-relative</feature>
<feature value="required">#textAlign</feature>
<feature value="required">#textDecoration-over</feature>
<feature value="required">#textDecoration-through</feature>
<feature value="required">#textDecoration-under</feature>
<feature value="required">#textDecoration</feature>
<feature value="required">#textOutline-blur</feature>

<feature value="required">#textOutline-blurred</feature>
<feature value="required">#textOutline-unblurred</feature>

<feature value="required">#textOutline</feature>
<feature value="required">#tickRate</feature>
<feature value="required">#time-clock-with-frames</feature>
<feature value="required">#time-clock</feature>
<feature value="required">#time-offset-with-frames</feature>
<feature value="required">#time-offset-with-ticks</feature>
<feature value="required">#time-offset</feature>
<feature value="required">#timeBase-clock</feature>
<feature value="required">#timeBase-media</feature>
<feature value="required">#timeBase-smpte</feature>
<feature value="required">#timeContainer</feature>
<feature value="required">#timing</feature>
<feature value="required">#transformation</feature>
<feature value="required">#unicodeBidi</feature>
<feature value="required">#visibility-block</feature>
<feature value="required">#visibility-inline</feature>
<feature value="required">#visibility-region</feature>
<feature value="required">#visibility</feature>
<feature value="required">#wrapOption</feature>
<feature value="required">#writingMode-horizontal-lr</feature>
<feature value="required">#writingMode-horizontal-rl</feature>
<feature value="required">#writingMode-horizontal</feature>
<feature value="required">#writingMode-vertical</feature>
<feature value="required">#writingMode</feature>
<feature value="required">#zIndex</feature>
<!-- optional (voluntary) feature support -->
</features>
<extensions xml:base="http://www.w3.org/2006/10/ttaf1/extension">

<extensions xml:base="http://www.w3.org/2006/10/ttaf1/extension/">

<!-- required (mandatory) extension support -->
<!-- optional (voluntary) extension support -->
</extensions>
</profile>

H References

This appendix is normative.

CSS2: Bert Bos et al., Cascading Style Sheets, Level 2 , W3C Recommendation, 12 May 1998. (See http://www.w3.org/TR/1998/REC-CSS2-19980512/ .)
GPS: Global Positioning System , US Naval Observatory. (See http://tycho.usno.navy.mil/gpsinfo.html .)
MIME: Ned Freed and Nathaniel Borenstein, Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types , RFC 2046, November 1996, IETF.(See http://www.rfc-editor.org/rfc/rfc2046.txt .)
RELAX NG: ISO/IEC 19757-2, Information technology – Document Schema Definition Language (DSDL) – Part 2: Regular-grammar-based validation – RELAX NG , International Organization for Standardization (ISO).
SMIL 2.1: Dick Bultermann, et al., Synchronized Multimedia Integration Language (SMIL 2.1) , W3C Recommendation, 13 December 2005. (See http://www.w3.org/TR/2005/REC-SMIL2-20051213/ .)
SMPTE 12M: ANSI/SMPTE 12M, Television, Audio and Film – Time and Control Code , SMPTE Standard.
SRGB: IEC 61966-2-1, Multimedia systems and equipment – Colour measurement and management – Part 2-1: Colour management – Default RGB colour space – sRGB , International Electrotechnical Commission (IEC).
UAAG: Ian Jacobs, Jon Gunderson, and Eric Hansen, Eds., User Agent Accessibility Guidelines 1.0 , W3C Recommendation, 17 December 2002. (See http://www.w3.org/TR/2002/REC-UAAG10-20021217/ .)
UTC: Recommendation TF.460, Standard-Frequency and Time-Signal Emissions , International Telecommunciations Union, Radio Sector (ITU-R).
UAX14: Asmus Freytag, Line Breaking Properties , Unicode Consortium, 29 August 2005. (See http://www.unicode.org/reports/tr14/tr14-17.html .)
WCAG: Wendy Chisholm, Gregg Vanderheiden, and Ian Jacobs, Eds., Web Content Accessibility Guidelines 1.0 , W3C Recommendation, 05 May 1999. (See http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505/ .)
XML 1.0: Tim Bray, et al. Extensible Markup Language (XML) 1.0 (Fifth Edition) , W3C Recommendation, 26 November 2008. (See http://www.w3.org/TR/2008/REC-xml-20081126/ .)
XML Base: Jonathan Marsh and Richard Tobin, Eds., XML Base (Second Edition) , W3C Recommendation, 28 January 2009. (See http://www.w3.org/TR/2009/REC-xmlbase-20090128/ .)
XML ID: Jonathan Marsh, Daniel Veillard, Norman Walsh, Eds., xml:id Version 1.0 , W3C Recommendation, 09 September 2005. (See http://www.w3.org/TR/2005/REC-xml-id-20050909/ .)
XML Media: Makato Murata, Simon St. Laurent, Kan Khon, Eds., XML Media Types , RFC 3023, January 2001, IETF.(See http://www.rfc-editor.org/rfc/rfc3023.txt .)
XML InfoSet: John Cowan and Richard Tobin, Eds., XML Information Set (Second Edition) , W3C Recommendation, 04 February 2004. (See http://www.w3.org/TR/2004/REC-xml-infoset-20040204/ .)
XML Media Types: Makato Murata, et al., XML Media Types , RFC 3023, January 2001, IETF.(See http://www.rfc-editor.org/rfc/rfc3023.txt .)
XML Namespaces 1.0: Tim Bray, et al. Namespaces in XML 1.0 (Second Edition) , W3C Recommendation, 16 August 2006. (See http://www.w3.org/TR/2006/REC-xml-names11-20060816/ .)
XML Schema Part 1: Henry S. Thompson, David Beech, Murray Maloney, Noah Mendelsohn, Eds., XML Schema Part 1: Structures , W3C Recommendation, 28 October 2004. (See http://www.w3.org/TR/xmlschema-1/ .)
XML Schema Part 2: Paul Biron and Ashok Malhotra, XML Schema Part 2: Datatypes , W3C Recommendation, 28 October 2004. (See http://www.w3.org/TR/xmlschema-2/ .)
XSL 1.1: Anders Berglund, Extensible Stylesheet Language (XSL) Version 1.1 , W3C Recommendation, 05 December 2006. (See http://www.w3.org/TR/2006/REC-xsl11-20061205/ .)

I Other References (Non-Normative)

CC-DECODER-REQ: Closed Caption Decoder Requirements for Analog Television , United States Code of Federal Regulations, Title 47, Volume 1, Part 15, § 15.119. (See http://edocket.access.gpo.gov/cfr_2005/octqtr/47cfr15.119.htm .)
CEA-608-C: EIA/CEA-608-C, Line 21 Data Services , EIA/CEA Standard, Consumer Electronics Association (CEA).
CSS3 Color: Tantek Çelik and Chris Lilley, CSS3 Color Module , W3C Candidate Recommendation, 14 May 2003. (See http://www.w3.org/TR/2003/CR-css3-color-20030514/ .)
DCMES 1.1: Dublin Core Metadata Initiative, Dublin Core Metadata Element Set, Version 1.1: Reference Description . (See http://dublincore.org/documents/dces/ .)
MPEG7-5: ISO/IEC 15938-5, Information technology – Multimedia content description interface – Part 5: Multimedia description schemes , International Organization for Standardization (ISO).
NSState: Norman Walsh, Ed., The Disposition of Names in an XML Namespace , TAG Finding, 9 January 2006. (See http://www.w3.org/2001/tag/doc/namespaceState-2006-01-09 .)
QAF SG: Karl Dubost, et al., QA Framework: Specifications Guidelines , W3C Recommendation, 17 August 2005. (See http://www.w3.org/TR/qaframe-spec/ .)
SMPTE 170M: ANSI/SMPTE 170M, Television – Composite Analog Video Signal – NTSC for Studio Applications , SMPTE Standard.
SVG 1.1: Jon Ferraiolo, Jun Fujisawa, Dean Jackson, Eds., Scalable Vector Graphics (SVG) 1.1 Specification , W3C Recommendation, 14 January 2003. (See http://www.w3.org/TR/2003/REC-SVG11-20030114/ .)
TTAF1-REQ: Glenn Adams, Ed., Timed Text (TT) Authoring Format 1.0 Use Cases and Requirements , W3C Working Group Note, 27 April 2006. (See http://www.w3.org/TR/2006/NOTE-ttaf1-req-20060427/ .)
XHTML 1.0: Steven Pemberton, et al., XHTML™ 1.0, The Extensible Hypertext Markup Language (Second Edition) , W3C Recommendation, 01 August 2002. (See http://www.w3.org/TR/2002/REC-xhtml1-20020801/ .)

J Requirements (Non-Normative)

The Distribution Format Exchange Profile (DFXP) of the Timed Text Authoring Format (TT AF) satisfies a subset of the requirements established by [TTAF1-REQ] . The following table enumerates these requirements and indicates the extent to which they are satisfied by this specification, where S denotes a requirement is satisfied, P denotes a requirement is partially satisfied, and N denotes a requirement is not satisfied.

Table J-1 – Requirement Satisfaction
ID	Name	Status	Comments
R100	Specification Format	S
R101	Specification Modularity	S
R102	Specification Organization	S
R103	Core and Periphery	S	TT extension namespaces
R104	Evolution of Core	S	TT extension namespaces
R105	Ownership of Core	S	TT namespaces
R106	Surjection of Core	S
R107	Evolution of Periphery	S	TT extension namespaces
R108	Ownership of Periphery	S	Non-TT namespaces
R109	Transformation	S	Supports 3GPP, QText, RealText, SAMI
R110	Streamable Transformation	S	Progressive decoding
R111	Accessibility – Content	S	Alternative document instances
R112	Accessibility – Authoring System	S
R200	Authorability	S
R201	Multiple Natural Languages	S	Alternative document instances
R202	Natural Language Coverage	S	Unicode 4.0
R203	Natural Language Association Granularity	S	See `xml:lang`
R204	Minimum Character Representability	S	Unicode 4.0
R205	Intrinsic and Extrinsic Text Content	P	Intrinsic only
R206	Markup Association	P	Intrinsic only
R207	Conditional Content	N
R208	Flowed Text	S
R209	Logical Flowed Text Vocabulary	S
R210	Presentational Flowed Text Vocabulary	S	Implied mapping from logical flowed text.
R211	Flowed Text Vocabulary Relationship	S
R212	Flowed Text Vocabulary Separation	N
R213	Non-Flowed Text	N
R214	Non-Flowed Text Vocabulary	N
R215	Hybrid Flowed and Non-Flowed Text	N
R216	Hyperlinking	N	Can support via XLink
R217	Embedded Graphics	N
R218	Non-Embedded Graphics	N
R219	Embedded Fonts	N
R220	Non-Embedded Fonts	N
R221	Descriptive Vocabulary	S	See `ttm:agent` , `ttm:role`
R222	Embedded Audio	N
R223	Non-Embedded Audio	N
R290	Markup Format	S
R291	Markup Format and Unicode Interaction	S
R292	Extrinsic Resource References	N	No extrinsic references
R293	Schema Validity Specification	S
R300	Inline Styling	S
R301	Inline Styling Form	P	Inline and referential styling
R301	Out-of-Line Styling	N
R301	Out-of-Line Styling Form	N
R304	Styling Prioritization	S
R305	Style Parameters – Aural	N
R306	Style Parameters – Visual	P	Supports absolute position, background color, color, display none, display alignment, font family, font size, font style, font weight, height, line height, origin, opacity, overflow, padding (before, after, start, end), text alignment, text shadow (as outline), visibility, width, writing mode, z-index
R307	Style Parameters – Temporal Fill Mode	S	See `tts:dynamicFlow`
R390	Style Parameter Symmetry	S
R391	Style Parameter Definitions	S
R392	Style Parameter Shorthands	S
R401	Inline Timing	S
R402	Out-of-Line Timing	N
R403	Synchronization Parameters	P	Supports begin, end, dur
R404	Synchronization Parameter Value Spaces	P	Supports offset values, media marker values (SMPTE 12M), wallclock values
R405	Time Containment Semantics	P	Supports sequential, parallel
R500	Animation Modes	P	Supports discrete
R501	Scroll Animation	S	See `tts:dynamicFlow`
R502	Highlight Animation	S	`<set tts:backgroundColor="..."/>`
R503	Fade Transition Animation	S	`<set tts:opacity="..."/>`
R504	Animated Style Parameters – Aural	N
R505	Animated Style Parameters – Visual	P	Supports animating background color, color, display, opacity, origin, visibility
N506	Animated Content	S
R600	Metadata Item Association	S	See `metadata` , `Metadata.class`
R601	Metadata Item Constituents	P	Supports name, value
R602	Metadata Item Value Representation	P	See `metadata`
R603	Metadata Item Extensibility	S	See `metadata`
R604	Metadata Item Validation	S	See `metadata`
R690	Dublin Core Preference	N	Uses `ttm:copyright` , `ttm:desc` , `ttm:title`

K Vocabulary Derivation (Non-Normative)

This appendix provides information about the derivation of TT AF vocabulary, separately describing derivation of elements and attributes.

K.1 Element Derivation

The first column of Table K-1 – Elements specifies a TT AF element vocabulary item; the second column specifies the syntactic and/or semantic model on which the vocabulary item is based; the third column specifies the reference that defines the model (if a model is indicated); the fourth column specifies details about the derivation; the last column refers to additional notes describing the nature of the derivation.

In the fourth column, which describes details of derivation, a notation is use to indicate the addition or removal of an attribute. For example, in the derivation of the tt:div element, the details column includes "-@class", which denotes that the class attribute that is specified for use with the xhtml:div model element is not specified for use with the corresponding TT AF element; in contrast, the details column includes "+@begin", which denotes that a begin attribute is added that is not specified for use with the xhtml:div model element.

Table K-1 – Elements
Element	Model	Reference	Details	Notes
`tt:body`	`xhtml:body`	[XHTML 1.0]	-@class, -@dir, -@lang, -@on, -@title; +@begin, +@dur, +@end, +@region, +@timeContainer, +@ttm:, +@tts:*; content model subsetted to zero or more division (div) children, and supersetted by optional metadata and animation children	1,2
`tt:br`	`xhtml:br`	[XHTML 1.0]	-@class, -@title; +@ttm:, +@tts:, +@xml:lang, +@xml:space; content model supersetted by optional metadata and animation children for congruity with other content vocabulary	1,2
`tt:div`	`xhtml:div`	[XHTML 1.0]	-@class, -@dir, -@lang, -@on, -@title; +@begin, +@dur, +@end, +@region, +@timeContainer, +@ttm:, +@tts:*, +@xml:space; content model subsetted to zero or more paragraph (p) children, and supersetted by optional metadata and animation children	1,2,3
`tt:head`	`xhtml:head`	[XHTML 1.0]	-@dir, -@lang, -@profile; +@id, +@xml:space; content model changed to optional metadata children, followed by optional styling child, followed by optional layout child	1,3
`tt:layout`	`fo:simple-page-master`	[XSL 1.1]	conceptual derivation	4
`tt:metadata`	`svg:metadata`	[SVG 1.1]	-@xml:base; +@ttm:*, +@xml:lang, +@xml:space; content model subsetted to foreign namespace element content only (no #PCDATA)	3,5
`tt:p`	`xhtml:p`	[XHTML 1.0]	-@class, -@dir, -@lang, -@on, -@title; +@begin, +@dur, +@end, +@region, +@timeContainer, +@ttm:, +@tts:*, +@xml:space; content model subsetted to zero or more span children, and supersetted by optional metadata and animation children	1,2,3
`tt:region`	`fo:region-*`	[XSL 1.1]	conceptual derivation	4
`tt:set`	`svg:set`	[SVG 1.1]	-@* except begin, dur, end; +@tts:*, +@xml:lang, +@xml:space	3,6
`tt:span`	`xhtml:span`	[XHTML 1.0]	-@class, -@dir, -@lang, -@on, -@title; +@begin, +@dur, +@end, +@region, +@timeContainer, +@ttm:, +@tts:*, +@xml:space; content model subsetted to zero or more #PCDATA or break (br) children, and supersetted by optional metadata and animation children	1,2,3
`tt:style`	style specification	[CSS2]	XML representation of identified set of pairs of style property name and value, with optional inclusion of other styles by reference to other style elements	7
`tt:styling`	`xhtml:style`	[XHTML 1.0]	XML representation of a set of style specifications sets, each represented by a style child element	1,7
`tt:tt`	`xhtml:html`	[XHTML 1.0]	-@dir, -@lang; +@id, +@ttp:*, +@xml:space; content model subsetted by permitting body and/or head to be optional	1,8
`ttm:actor`	`mpeg7:Creator`	[MPEG7-5]	conceptual derivation	4
`ttm:agent`	`mpeg7:Agent`	[MPEG7-5]	conceptual derivation	4
`ttm:copyright`	`mpeg7:CopyrightString`	[MPEG7-5]	conceptual derivation	4
`ttm:desc`	`svg:desc`	[SVG 1.1]	-@class, -@style, -@xml:base	2,5,9
`ttm:name`	`mpeg7:Name`	[MPEG7-5]	conceptual derivation	4
`ttm:title`	`svg:title`	[SVG 1.1]	-@class, -@style, -@xml:base	2,5,9
`ttp:extension`	`@requiredExtensions`	[SVG 1.1]	conceptual derivation	10
`ttp:extensions`	`@requiredExtensions`	[SVG 1.1]	conceptual derivation	10
`ttp:feature`	`@requiredFeatures`	[SVG 1.1]	conceptual derivation	10
`ttp:features`	`@requiredFeatures`	[SVG 1.1]	conceptual derivation	10
`ttp:profile`	`@baseProfile`	[SVG 1.1]	conceptual derivation	11

Note:

Derivation is indicated with respect to the strict DTD defined by [XHTML 1.0] , §A.1.
The class attribute is effectively replaced by the style attribute, which, instead of specifying an inline style, refers indirectly to one or more style elements that define a set of style specification sets.
The xml:lang and xml:space attributes are defined for all element types in order to support their inheritance semantics to operate in the context of foreign namespace elements.
Derivation is conceptual (notional) only.
The xml:base attribute is not used since there are no external references from core vocabulary.
The attributeName and to attributes of svg:set are replaced by the direct expression of the target attribute name and value by use of a tts:* attribute.
CSS style specification syntax is mapped to XML by use of attributes defined in the TT Style Namespace.
The xml:id attribute is defined for use on all element types.
The style attribute is supported only on content elements.
Derived from the use of @requiredExtensions and @requiredFeatures on the svg:svg element, but extended to support distinct specification of optionality.
Derived from the use of @baseProfile and @version on the svg:svg element.

K.2 Attribute Derivation

The first column of Table K-2 – Attributes specifies a TT AF attribute vocabulary item; the second column specifies the syntactic and/or semantic model on which the vocabulary item is based; the third column specifies the reference that defines the model (if a model is indicated); the fourth column specifies details about the derivation; the last column refers to additional notes describing the nature of the derivation.

In the fourth column, which describes details of derivation, a notation is use to indicate the addition or removal of an attribute value. For example, in the derivation of the timeContainer attribute, the details column includes "-excl", which denotes that the excl value that is specified for use with the timeContainer model attribute is not specified for use with the corresponding TT AF attribute; similarly, an "+ value " in the details column indicates that the attribute's values have been extended to include value .

Only those attributes that are specified for use on more than one TT AF element type are listed below. Those per-element namespace attributes that are uniquely defined for a specific TT AF element type are not listed below, but are considered to be part of the specific element type's derivation described in Table K-1 – Elements above.

Table K-2 – Attributes
Attribute	Model	Reference	Details	Notes
`begin`	`begin`	[SMIL 2.1]	see notes	2,3,4
`dur`	`dur`	[SMIL 2.1]	see notes	2,3,4
`end`	`end`	[SMIL 2.1]	see notes	2,3,4
`region`	`master-reference`	[XSL 1.1]	conceptual derivation
`style`	`class`	[CSS2]	dereferences style specification(s) directly
`timeContainer`	`timeContainer`	[SMIL 2.1]	-excl, -none; no default attribute value	5
`ttm:agent`	none		used to attribute agent of content
`ttm:role`	none		used to attribute role of content
`ttp:cellResolution`	none		expresses uniform grid resolution for cell based coordinates
`ttp:clockMode`	none		determines how to interpret time expressions
`ttp:frameRate`	none		expresses integral frame rate
`ttp:frameRateMultiplier`	none		used to express non-integral, rational frame rates
`ttp:markerMode`	none		expresses marker continuity semantics
`ttp:pixelAspectRatio`	none		expresses pixel aspect ratio of related media
`ttp:profile`	none		expresses profile of TT AF used by document instance
`ttp:smpteMode ttp: dropMode`	none		expresses frame counting (drop) modes
`ttp:subFrameRate`	none		expresses sub-frame rate
`ttp:tickRate`	none		used to interpret tick based time expressions
`ttp:timeBase`	none		used to interpret semantics of time expressions
`tts:backgroundColor`	`background-color`	[XSL 1.1]	`-inherit`	1,6
`tts:color`	`color`	[XSL 1.1]	`-inherit`	6
`tts:direction`	`direction`	[XSL 1.1]	`-inherit`
`tts:display`	`display`	[CSS2]	only `auto` , `none`
`tts:displayAlign`	`display-align`	[XSL 1.1]	`-inherit`	1
`tts:dynamicFlow`	none		defines dynamic overflow behavior
`tts:extent`	`width` , `height`	[XSL 1.1]	shorthand property
`tts:fontFamily`	`font-family`	[XSL 1.1]	`-inherit` , extends generic family names	1
`tts:fontSize`	`font-size`	[XSL 1.1]	`-inherit`	1,7
`tts:fontStyle`	`font-style`	[XSL 1.1]	`-inherit` , uses alias `reverseOblique` for `backslant`	1
`tts:fontWeight`	`font-weight`	[XSL 1.1]	`-inherit` , `-bolder` , `-lighter` , `-<number>`	1
`tts:lineHeight`	`line-height`	[XSL 1.1]	`-inherit` , `-<number>` , `-<space>`	1
`tts:opacity`	`opacity`	[CSS3 Color]	`-inherit`
`tts:origin`	`top` , `left`	[XSL 1.1]	shorthand property
`tts:overflow`	`overflow`	[XSL 1.1]	`-inherit` , `-auto` , `-error-if-overflow` ; `+dynamic`	8
`tts:padding`	`padding`	[XSL 1.1]	`-inherit`	9
`tts:showBackground`	`showBackground`	[SMIL 2.1]	`-inherit`
`tts:textAlign`	`text-align`	[XSL 1.1]	`-inherit`	1
`tts:textDecoration`	`text-decoration`	[XSL 1.1]	`-inherit`	1,10,13
`tts:textOutline`	`text-shadow`	[XSL 1.1]	`-inherit`	11,13
`tts:unicodeBidi`	`unicode-bidi`	[XSL 1.1]	`-inherit`	1
`tts:visibility`	`visibility`	[XSL 1.1]	`-inherit` , `-collapse`
`tts:wrapOption`	`wrap-option`	[XSL 1.1]	`-inherit`	1
`tts:writingMode`	`writing-mode`	[XSL 1.1]	`-inherit` , `+tblr`	1
`tts:zIndex`	`z-index`	[XSL 1.1]	`-inherit`	1
`xml:id`	`xml:id`	[XML ID]	complies with model
`xml:lang`	`xml:lang`	[XML 1.0]	complies with model
`xml:space`	`xml:space`	[XML 1.0]	see notes	12

Note:

Attribute name and/or value(s) are normalized to use lowerCamelCase naming convention.
Restricted to expressing a clock value that denotes one of the following in accordance to whether the parameter expressed by the ttp:timeBase attribute is media , smpte , or clock , respectively: (1) an offset from an implicit syncbase that is linked to a media time line, (2) an event time that represents the occurrence of an implicit media marker, or (3) a wallclock time.
Syntactically subsets and supersets the [SMIL 2.1] Clock-value syntax as follows: (1) requires non-negative Full-clock-value or Timecount-value ; (2) if Full-clock-value then hours must be two or more digits; (3) if Timecount-value , then metric must be specified; (4) uses m as alias for min metric to denote minutes; (5) adds f and t metrics denoting frames and ticks, respectively; (6) adds alternative expression of optional Fraction in Full-clock-value by specifying frame count or frame count with subframe count.
Interpretation of time expression is further constrained by parameters expressed by ttp:clockMode , ttp: dropMode ,ttp:frameRate , ttp:frameRateMultiplier , ttp:markerMode , ttp:smpteMode , ttp:subFrameRate , ttp:tickRate , and ttp:timeBase attributes.
Uses subset of named colors from model to which two aliases are added as follows: magenta as fuchsia , and cyan as aqua .
If not specified, then parallel (par) container semantics apply to the element types specified by 10.2.4 timeContainer .
Restricts size to length specification which can be a percentage; adds optional second length (or percentage) for specifying separate horizontal and vertical scaling of glyph's EM square.
The value dynamic is defined in terms of the tts:dynamicFlow style property.
Expressed in terms of writing mode relative padding properties rather than absolute padding properties.
Excludes blink and no-blink values.
Uses only one length specification instead of two, where one length defines distance of outline effect from nominal edge of glyph contour outline perpendicular to point of glyph contour. Percentage lengths are also added to express outline effect in relative to font size. Outline effects are intended to be drawn both outside of outer closed contours and inside of inner closed contours.
On root element, default attribute value specified as default , which is defined in terms of whitespace normalization. Semantics of preservation and default normalization are defined in terms of presentation semantics by 7.2.3 xml:space .
Defined to be inheritable.

L QA Framework Compliance (Non-Normative)

This appendix specifies the compliance of this specification with the requirements and guidelines defined by QA Framework Specifications Guidelines [QAF SG] .

L.1 Requirements

Table L-1 – QA Framework Requirements Checklist
Requirement	YES	NO	N/A	Notes
Requirement 01: Include a conformance clause	YES
Requirement 02: Define the scope.	YES
Requirement 03: Identify who or what will implement the specification.	YES
Requirement 04: Make a list of normative references.	YES
Requirement 05: Define the terms used in the normative parts of the specification.	YES
Requirement 06: Create conformance labels for each part of the conformance model.	YES
Requirement 07: Use a consistent style for conformance requirements and explain how to distinguish them.	YES
Requirement 08: Indicate which conformance requirements are mandatory, which are recommended, and which are optional.	YES
Requirement 09: If the technology is subdivided, then indicate which subdivisions are mandatory for conformance.	YES
Requirement 10: If the technology is subdivided, then address subdivision constraints.	YES
Requirement 11: Address Extensibility.	YES
Requirement 12: Identify deprecated features.			N/A	1
Requirement 13: Define how each class of product handles each deprecated feature.			N/A	1

Note:

No feature is deprecated by this version of this specification.

L.2 Guidelines

Table L-2 – QA Framework Guidelines Checklist
Guideline	YES	NO	N/A	Notes
Good Practice 01: Define the specification's conformance model in the conformance clause.	YES
Good Practice 02: Specify in the conformance clause how to distinguish normative from informative content.	YES
Good Practice 03: Provide the wording for conformance claims.	YES
Good Practice 04: Provide an Implementation Conformance Statement Pro Forma.		NO
Good Practice 05: Require an Implementation Conformance Statement as part of valid conformance claims.	YES
Good Practice 06: Provide examples, use cases, and graphics.	YES
Good Practice 07: Write sample code or tests.	YES
Good Practice 08: When imposing requirements by normative references, address conformance dependencies.	YES			1
Good Practice 09: Define unfamiliar terms in-line and consolidate the definitions in a glossary section.	YES
Good Practice 10: Use terms already defined without changing their definition.	YES			2
Good Practice 11: Use formal languages when possible.	YES
Good Practice 12: Write Test Assertions.		NO		3
Good Practice 13: Create subdivisions of the technology when warranted.	YES
Good Practice 14: If the technology is profiled, define rules for creating new profiles.	YES
Good Practice 15:Use optional features as warranted.	YES
Good Practice 16: Clearly identify optional features.	YES
Good Practice 17: Indicate any limitations or constraints on optional features.	YES
Good Practice 18: If extensibility is allowed, define an extension mechanism.	YES
Good Practice 19: Warn extension creators to create extensions that do not interfere with conformance.	YES
Good Practice 20: Define error-handling for unknown extensions.	YES			4
Good Practice 21: Explain how to avoid using a deprecated feature.			N/A	5
Good Practice 22: Identify obsolete features.			N/A	5
Good Practice 23: Define an error handling mechanism.	YES

Note:

When making normative references to external specifications, specific clauses or sections are cited.
See also K Vocabulary Derivation .
Test assertions and test suites will be provided prior to entering Proposed Recommendation (PR) phase.
See criterion #3 in 3.2 Processor Conformance and definition of TT AF Abstract Document Instance .
No feature is deprecated or obsoleted by this version of this specification.

M Streaming DFXP Content (Non-Normative)

DFXP Content is designed to support streamability by implementing the following properties:

can be progressively encoded (i.e., does not require computing subsequent data prior to sending current data);
can be progressively decoded (i.e., does not require forward references, but uses only reverse references when necessary);
does not require dereferencing (and subsequent loading) of any resources other than DFXP content (i.e., no embedded URIs);
does not support alternative content forms (e.g., different language, graphics formats, time bases) in a single document;
has timing structure compiled into inline format that makes possible a temporal ordering of content that follows temporal presentation order;
constrains content models to prevent arbitrary nested content structures;

One possible means by which DFXP Content may be streamed is to partition a DFXP document instance's information set into non-overlapping fragments, where one particular fragment, call it the root fragment , represents the front matter (head) of the document instance as well as its top level structural elements, and other fragments represent content whose time intervals are expected to be active in parallel.

In applications that require arbitrary (random) entry into a stream, i.e., the property of being able to start reading data at an arbitrary data access unit, the root fragment will be repetitively transmitted (inserted) into the stream in order to permit a decoder to resynchronize and acquire sufficient structural information in the information set in order to interpret subsequent content fragments.

An example of such a fragmentation of a DFXP document instance is shown in Figure 2 3 – Fragment Streaming .

Figure 2 3 – Fragment Streaming

Note:

This specification does not define a transport buffer model or a decoder capabilities model.

N Acknowledgments (Non-Normative)

The editor acknowledges the members of the Timed Text Working Group, the members of other W3C Working Groups, and industry experts in other forums who have contributed directly or indirectly to the process or content of creating this document.

The current and former members of the Timed Text Working Group are: Glenn Adams (Samsung Electronics Co., Ltd.), John Birch (Invited expert), Kees Blom (CWI), Dick Bulterman (CWI), Frans de Jong (Invited expert), Mike Dolan (W3C Invited Experts), Geoff Freed (WGBH National Center for Accessible Media), Sean Hayes (Microsoft Corporation), David Kirby (British Broadcasting Corporation), Andrew Kirkpatrick (Adobe Systems Inc.), Philippe Le Hégaret (W3C/MIT), Matthew May (Adobe Systems Inc.), Soohong Daniel Park (Samsung Electronics Co., Ltd.), Brad Botkin, Donald Evans, Markus Gylling, Markku Hakkinen, Erik Hodge, Masahiko Kaneko, George Kerscher, Chris Lilley, Thierry Michel, Patrick Schmitz, David Singer.

The editor wishes to especially acknowledge the following contributions by members: Micheal Dolan (SMPTE time codes, streaming; SMPTE liaison), David Kirby (introductory example document; SMPTE time codes, descriptive metadata; EBU/AAF liaison), Geoff Freed (styling and example images of style properties), Sean Hayes (advanced profile concepts, including applicative timing), Eric Hodge (timing), Thierry Michel (metadata), and Dave Singer (animation, scrolling).

The Timed Text Working Group has benefited in its work from the participation and contributions of a number of people not currently members of the Working Group, including in particular those named below. Affiliations given are those current at the time of their work with the WG.

John Birch, Screen Subtitling Systems; Bert Bos, W3C (chair, CSS WG); Martin Dürst, W3C (leader, I18N Activity); Al Gilman (chair, WAI Protocol and Formats WG); Philipp Hoschka, W3C (leader, Interaction Domain); Chris Lilley, W3C (chair, SVG WG).

The editor wishes to especially acknowledge the following contributions by non-members: John Birch (dynamic flow).

O Change History (Non-Normative)

O.1 Changes from First to Second Last Call Working Draft

Technical Changes
The following changes result in a technical change of the conformance
criteria, the normative abstract document type that is defined
for use with DFXP, or the defined value space of an attribute or
property:
* Update namespace URIs to use 2006/04 instead of 2004/11;
* Remove ttp:defaultLengthUnit definition and all references;
  + change initial (default) value definition of tts:fontSize to
    be 1/24th of the height of the root container in all cases;
  + change syntax of scalar form of <length> to require units
* Remove ttp:defaultTimeMetric definition and all references;
  + change syntax of <duration> to require a metric
* Add "transcription" to ttm:role enumeration in section 12.2.2;
* In section 8.2.16, change "dynamic" value to read "scroll" instead,
  which is already defined by CSS/XSL and given UA dependent
  semantics; here we will specify fixed semantics and map to dynamic
  flow; change also usage in 8.1.7 to refer to "scroll";
* In section 6.2.1, change implied default value of ttp:cellResolution
  from 1col/1row to 32cols/15rows, based on CEA/EIA-608-C maximum values;
* In 8.3.12, add "cyan" and "magenta" as aliases for "aqua" and
  "fucshia", since it turns out these are defined by SVG1.0;
* Add following new values for ttm:role to support EIA/CEA-708 caption
  text functions: dialog, expletive, narration, quality, source,
  suppressed; remove associated editorial note;
* In 3.1, add new conformance criteria item 1 that specifies the use
  of application/ttaf+xml as MIME media type with optional "profile"
  parameter; use new references to MIME and XML Media Types;
* Remove begin, dur, and end attributes and descriptions thereof from
  <tt/> and <layout/>;
* Move description of tts:extent attribute from <tt/> to
  <body/>;
* Change "meta" element name to "metadata" to match SVG usage, on
  which this vocabulary item is modeled;
* Remove name attribute from <metadata/> element;
* Change initial (default) value definition of tts:fontSize to
  be 1c (one grid cell) in order to match implied default value for
  ttp:cellResolution row count;
* For sake of symmetry, add Metadata.class and Animation.class children to
  content model of <br/>;
* Add style, ttm:*, tts:* and foreign namespace attributes to
  <br/>;
* Add usage of tts:padding property that takes three length specifications;
* Add left and right values to textAlign;
* Add monospace, serif, and sansSerif to generic font family names;
* Add missing "auto" value to zIndex, and make "auto" initial value
  in order to comply with XSL/CSS usage;
* Add means to specify rate (in units per second) to definition of
  flowIntervalArguments in section 8.3.8;
* Populate Appendix B on Dynamic Flow Processing which defines normative
  semantics (previously unspecified);
Editorial Changes
The following changes are editorial in nature or entail semantic
clarifications that do not affect the abstract document type or defined
schemas for DFXP:
* Add "Contributing Authors" to preamble, listing contributors;
* Merge current and former members description in Appendix H (now
  Appendix K);
* Remove references to AFXP as follows:
  + remove 1st note in section 1
  + remove 1st note in section 1.1
  + remove definition of AFXP from glossary
  + remove section 4.2
  + remove AFXP profile entry from Table 2 - Profiles
  + remove reference to 2nd catalog in section 5.3 preamble
  + remove last clause of 2nd para of section 5.3
  + change "AFXP" to "future profiles" in 1st para of section 5.3.1
  + remove section 5.3.2
  + remove last sentence of 2nd note in section 7.1.4
  + remove last sentence of 1st note in section 7.1.6
  + change "AFXP" to "advanced profiles" in 3rd para of Appendix H (now
  Appendix K);
* Add clarifying language in the last para of section 8.3.6;
* Clarify definition of "Valid Abstract Document Instance" in section 4
  to account for the pruning of attributes in other namespaces and
  residual requirements on the presence and value type of attributes;
  + remove redundant definition in glossary to prevent competing
    definitions
* Add informative reference to SMPTE170M (for NTSC); add a
  reference to this bibliographic entry from the 1st note under
  section 6.2.4; add new sentence to this same note indicating
  that other frame rate multipliers apply in other regions and
  with other video formats;
* Add normative reference to UAAG; add recommendation in
  conformance clause 3.2 item (5) that a presentation processor
  should satisfy UAAG defined guidelines;
* Add note in introduction expressing that a related sign language
  representation may be appropriate in some circumstances, but that
  this is not addressed explicitly by DFXP;
* Add note in section 6.2.11 indicating that control over state of
  external media time base is outside the scope of DFXP;
* Add note in section 5.2 indicating possible uses of profile
  information;
* Fix typos:
  + section 6.2.1: s/express number/express the number/
  + section 6.2.5 (now 6.2.3): s/in document/in a document/
  + section 6.2.6 (now 6.2.4): s/MHz/Hz/
* Add note to 6.2.2 referring to section 10.3 Time Value Expressions;
* Add normative reference to UTC, using reference in section 6.2.2;
* Add normative reference to GPS, using reference in section 6.2.2;
* Add note to 6.2.2 summarizing difference between GPS and UTC;
* Add para to 6.2.2 clarifying that ttp:clockMode is significant
  only on <tt/> element;
* In section 8.3.11, add or refer to definitions of "px", "em", and
  "c";
* In section 7.2.3, replace definition of semantics of xml:space
  values with a new definition that maps to XSL-FO properties;
* In section 9.3.2, add new item (8) that specifies mapping for
  <br/> elements to <fo:character/>;
* In section 4, add new step 2 to definition of Abstract Document
  Instance, which is needed to remove certain XML whitespace that
  remains after pruning elements; e.g., a <br/> element may have
  children from another namespace, that, after pruning, would result
  in a non-empty <br/> element; this new step ensures that the
  element is emptied prior to validation against its abstract
  document type;
* In section 8 preamble, add new para indicating that no normative
  use of a stylesheet PI is defined;
* In section 8.2.16, add condition tts:wrapOption="noWrap" in note;
* In section 8.2.22, move visibility="hidden" from <p/> to <span/>s;
  otherwise, content would remain hidden due to <p/> being hidden;
* Add informative reference to CEA/EIA-608-C; use this reference
  in a new note in 6.2.1;
* Add note in 6.2.1 explaining that it is not expected that glyph
  areas align with uniform grid defined by ttp:cellResolution,
  indicate that such alignment would occur only when using monospace
  font whose EM square exactly matches grid's cell size;
* Add normative reference to SRGB definition;
* Add normative use of SRGB in section 8.3.2 <color> and 8.3.12 <namedColor>
* In 8.3.2, add para indicating that SRGB is used for both input and
  output of notional composition functions; add note indicating that
  a presentation processor may actually use another color space for
  internal or external purposes;
* In 8.2.14, specify that opacity applies on a linear scale;
* Add informative reference to SVG 1.0;
* Add note in 8.3.12 indicating that named color set is a strict
  subset of SVG 1.0 named color set;
* Add empty informative Appendices H, I, and L, to document Vocabulary
  Derivation, QA Framework Compliance, and Change History,
  respectively; renumber former appendices G and H as Appendices J
  and K, respectively;
* Add normative reference to RFC2046, MIME Media Types;
* Add normative reference to RFC3023, XML Media Types;
* Change description of implied begin/end on <tt/> to refer to
  external context temporal interval;
* Change description of implied begin/end on <body/> to refer to
  external time interval;
* In 7.1.2, 8.1.1, and 9.1.1, specify that implied time intervals of
  head, styling, and layout are coterminous with external time
  interval;
* In 9.1.2, indicate that begin/end points specified on <region/>
  are relative to the time interval of the nearest ancestor associated
  with a time interval;
* In 9.1.2, remove constraint that if no tts:extent is specified in
  computed style set then no content is flowed into region; this
  constraint is redundant since the initial value of tts:extent is
  "auto" which is defined to be extent of root container;
* Fix typos:
  + section 9.1.2, s/layout/region/ in para describing dur attribute;
* Add note at end of the preamble to section 8.2, [Styling] Attribute
  Vocabulary, indicating that (to support inheritance) any style
  property may be specified on any content element independently of
  whether it applies to that element;
* Remove note in 7.1.7 that indicated that <br/> is empty in
  the reduced XML infoset, which no longer holds as both metadata and
  animation children may be present;
* In Appendix I, add table I-1 with element vocabulary derivation;
* Define monospace to be either serifed or not; define serif and
  sansSerif to be equivalent to proportionalSerif and proportionalSansSerif,
  respectively;
* Add time metric to time expressions in example content;
* Add definition of implicit duration of document instance in section 7.1.1;
* In definition of <time-expression> syntax in section 10.3.1,
  remove paragraph referring to default time metric, which no longer
  applies now that time metric must be specified;
* In Appendix I, add table I-2 with attribute vocabulary derivation;
* Add definition of percentage lengths to each style property
  definition. Percentages apply to the following styles: extent,
  fontSize, lineHeight, origin, padding, and textOutline;
* Fill in Appendix I with QA Framework compliance information;
* Add section 5.3.2 defining a presently empty "Extension Catalog"
  that serves as a placeholder for future standardized extensions and
  additionally specifies that document instance may contain arbitrary
  namespace qualified elements and attributes from other namespaces;
* Add section 3.3 defining conformance claims and requirements
  regarding for providing an implementation compliance statement;
* Add hyperlinks throughout document for references to elements,
  attributes, and value expressions;
* Add new Appendix F containing sample code and sample compile,
  load, run session transcript;
* Change IDREF to IDREFS as value of ttm:agent as found in prose in
  section 12.2.1;

O.2 Changes from Second Last Call Working Draft to First Candidate Recommendation

Technical Changes
The following changes result in a technical change of the conformance
criteria, the normative abstract document type that is defined
for use with DFXP, or the defined value space of an attribute or
property:
* Restore support for nested div and span elements [that had
  been removed in an early working draft].
* Change "id" attribute to "xml:id".
* Add tts:textDecoration style property.
* Update namespace URIs to use 2006/10 instead of 2006/04.
* Update profile URIs to use 2006/10 instead of 2006/04.
Editorial Changes
The following changes are editorial in nature or entail semantic
clarifications that do not affect the abstract document type, defined
schemas, or conformance criteria for DFXP:
* Update "status of this document" (SOTD) section to
  reflect CR transition.
* Add normative reference to xml:id recommendation.
* Add note in section 9.3.3 indicating that intermediate document
  examples are internal processing states and do not represent
  valid DFXP documents.
* Add "Except for transparent, " to note in section 8.3.12.
* Add recommendation, in section 3.1 item 5, that conformant
  reduced infoset "should" adhere to WCAG1.0.
* Add normative reference to WCAG1.0.
* Update informative reference to SVG1.0 to reference SVG1.1
  instead.
* Insert new (normative) Appendix D that specifies the
  MIME Media Type registration information for application/ttaf+xml.
* Add normative reference to RFC3023 tagged as [XML Media Types],
  for use by new Appendix D.
* Normalize and add missing dates of W3C Recs cited in
  Appendices E (References) and F (Other References).
* In Table 4, express groups as choice lists instead of
  sequences (which might have been confusing).
* Revise content models of XML Representation of div, p,
  and span element information items in order to make
  reference to Block.class and Inline.class element
  groups.
* Add "This appendix is normative" to beginning of each
  normative appendix.
* Add clarifications in sections 8.3.13 and 8.3.14 that
  syntactic element "char" adheres to production [2] of
  XML1.1, while syntactic element "S" adheres to
  production [3] of XML1.1.
* Add note to section 7.1.7 (and rearrange paragraph ordering)
  to indicate that two <br> elements are intended to
  produce two forced line breaks in a sequence.
* Add note to section 6.2.4 that indicates that PAL
  formatted video nominally uses a 1:1 frame rate multiplier
  (except for PAL/M).
* Add note to end of section 9.3.2 that indicates that a
  compliant XSL1.0 presentation processor may be insufficient
  to satisfy the presentation semantics of DFXP.
* Clarify syntax of <alpha> style value expression to
  use XML Scheme Datatype lexical representation of xs:float,
  which was the intended syntactic value space for this
  expression.
* Clarify that ttp:cellResolution columns or rows must not be zero
  if present.
* Clarify that ttp:frameRate must be greater than zero if present.
* Clarify that ttp:frameRateMultipler denominator must not be zero
  if present. Correct misspelling "demoninator".
* Clarify that ttp:pixelAspectRatio width or height must not be zero
  if present.
* Clarify that ttp:subFrameRate must not be zero if present.
* Clarify that ttp:tickRate must not be zero if present.
* Remove superfluous end tag close (>) in XML representation of
  metadata element information item in section 12.1.1.
* Add clarification that the declared value of an inline style
  attribute on body, region, and style elements must not be "inherit".
* Add clarification in section 8.5.1 item 2 that use of value
  "inherit" does not apply if element is body element.
* Clarify that tt element establishes the root stacking context
  for the purpose of interpreting the tts:zIndex style property;
  this corresponds with the prescribed mapping of tt:tt to fo:root
  as described in section 9.3.2 item 3.
* Clarify that ttp:{markerMode,smpteMode,tickRate,timeBase} are
  significant only when specified on tt element.
* Add note at end of section 8.2.17 that padding style attribute
  is based on XSL 1.0 shorthand "padding" property except that
  the individual values map to writing mode relative padding
  properties, i.e., padding-before, padding-after, etc.
* Update attribute derivation table (Appendix I.2) to reflect
  addition of tts:textDecoration and change from id to xml:id.
* Update publishing date and dates in SOTD CR publication.
* Update SOTD to remove use of sample code as satisfying 2
  implementation convention for exit criteria. Note that sample
  code can still serve as 1 implementation of 2 required.
* Add paragraph to SOTD describing unsatisfied comments during
  first LC.
* Change "reference code" to read "sample code".

O.3 Changes from First Candidate Recommendation to Third Last Call Working Draft

Technical Changes
The following changes result in a technical change of the conformance
criteria, the normative abstract document type that is defined
for use with DFXP, or the defined value space of an attribute or
property:
* Change TT Style Namespace to use #styling instead of #style as
  fragment identifier [I-087]. 
* Add ttp:{profile,features,feature,extensions,extension} element types
  [I-060].
* Add Parameters.class group, containing ttp:profile element, to content
  model of head element [I-060].
* Define three normative profiles: dfxp-{transformation,presentation,full},
  with dfxp-transformation being the default in absence of declaration
  [I-060, I-096].
* Subdivide processor conformance into transformation and presentation
  processors, mandating support for the respective profile [A-035].
* Add optional tts:extent attribute to tt element [A-028, I-069].
* Change default time containment of body element to 'par' [I-041].
* Remove 'inherit' value from all tts:* style attributes [I-054].
* Allow unquoted font family names to contain whitespace in
  <familyName> style value expression used with tts:fontFamily
  attribute [I-033].
* Change 'scroll' value to 'dynamic' on tts:overflow attribute [I-082].
* Add 'rollUp' value to tts:dynamicFlow attribute [A-034, I-101].
* Remove (1) 'within' flow function, (2) 'block', 'inline', and 'pixel'
  flow units, (3) 'fade' flow style, and (4) flow transition and flow
  transition styles from <flowFunction> style value expression
  [I-081, I-086, I-100].
* Rename intra(..) and inter(..) to fill(..) and clear(..), respectively,
  in <flowIntervalFunction> style value expression [I-102].
* Allow tts:display style property to apply to region element [I-051].
* Allow ttm:role attribute on region element [A-032].
* Improve content model of metadata element [I-097].
* Change data type of ttm:role attribute to NMTOKENS [I-089].
* Add 'description' value to ttm:role attribute [I-008].
Editorial Changes
The following changes are editorial in nature or entail semantic
clarifications that do not affect the abstract document type, defined
schemas, or conformance criteria for DFXP:
* Clarify prose with respect to support for nested div and span [A-024, I-028].
* Define default region in absence of explicit region [A-026, I-012, I-042].
* Map anonymous spans to fo:inline only when parent is p or span [A-027, I-037].
* Fix inconsistencies regarding time containment semantics [A-029].
* Clarify semantics of dur and end attributes [A-030].
* Unify specification of behavior of style resolution processing [A-033, I-032, I-040, I-050].
* Add examples of metadata and animation vocabulary [I-009].
* Revert XML and XML Namespace references to their 1.0 versions [I-015].
* Fix incorrect reference to SMIL2 sections [I-016].
* Fix syntactic definition of <duration> style value expression [I-017].
* Correct name of tts:textDecoration value 'lineThrough' [I-027].
* Clarify prose describing <opacity> style value expression [I-035, I-090].
* Clarify processing and inheritance of anonymous spans [I-034, I-036, I-077].
* Fix example code for content hierarchy region mapping [I-043].
* Fix various typos and formatting issues [I-044, I-045, I-056, I-073, I-076].
* Add missing inheritance and percentage constraints [I-046].
* Fix ordering and missing entry in list of style value expressions [I-052].
* Designate tts:textDecoration and tts:textOutline as inheritable [I-055].
* Make all style properties animatable [I-059].
* Correct flow interval computation with definite rate [I-061].
* Clarify dynamic flow buffer semantics [I-062, I-063, I-066, I-067, I-104].
* Clarify dynamic flow timing semantics [I-064, I-104].
* Clarify affect of animation of styles and dynamic flow [I-065].
* Clarify semantics of space filling of region [I-068].
* Clarify extent of region with respect to tts:overflow semantics [I-070].
* Update XSL reference to 1.1 version [I-079].
* Remove appendix containing sample code [I-080].
* Clarify dynamic flow operation semantics [I-083, I-099].
* Clarify default flow style semantics [I-084].
* Clarify default denominator on ttp:frameRateMultiplier [I-085].
* Add missing style default semantics [I-091].
* Clarify mutability of TT AF namespaces [I-094].
* Clarify constraints on syntax of flow functions [I-103].
* Clarify interaction between dynamic flow and wrap option processing [I-105].
* Clarify line breaking semantics [I-106].
* Enlarge syntactic treatment of foreign attributes on head element [I-110].
* Fix note regarding context of usage of metadata items [I-111].
* Remove style and metadata extension namespaces [I-112].
* Clarify region association algorithm [I-118].

O.4 Changes from Third Last Call Working Draft to Second Candidate Recommendation

Technical Changes
The following changes result in a technical change of the conformance
criteria, the normative abstract document type that is defined
for use with DFXP, or the defined value space of an attribute or
property:
* Change value syntax of ttp:frameRateMultiplier and ttp:pixelAspectRatio
  to use whitespace separator rather than COLON ':' separator [I-122].
* Add flow style duration argument to flow interval function [I-126].
* Add 'break' value as flow interval argument in flow interval function [I-127].
* Add missing feature designators [I-130].
* Add path separator '/' to end of TT Profile, Feature, and Extension
  Namespace strings, which are used as base URIs [I-131].
* Prohibit use of 'dur' attribute when operating in discontinuous marker
  mode [I-141].
* Change name of ttp:smpteMode attribute to ttp:dropMode [I-142].
Editorial Changes
The following changes are editorial in nature or entail semantic
clarifications that do not affect the abstract document type, defined
schemas, or conformance criteria for DFXP:
* Change #style to #styling suffix of TT Styling Namespace in RNC
  schema [I-119].
* Remove use of TT extension namespaces in RNC schema [I-119].
* Add missing direction and unicodeBidi style attributes to
  TTAF.Styling.attrib in RNC schema [I-120].
* Enhance foreign element pattern for metadata content model in RNC
  schema [I-121].
* Clarify that numerator of ttp:frameRateMultiplier must be non-zero [I-123].
* Remove erroneous specification of inheritance on tts:displayAlign [I-125].
* Fix typos in descriptive prose of flow timers [I-128].
* Update tts:dynamicFlow attribute example t

Timed Text (TT) Authoring Format 1.0 – Distribution Format Exchange Profile (DFXP)

W3C Working Draft 02 June Candidate Recommendation 24 September 2009

Abstract

Status of this Document

Table of Contents

Appendices

1 Introduction

1.1 System Model

1.2 Document Example

2 Definitions

2.1 Acronyms

2.2 Terminology

2.3 Documentation Conventions

3 Conformance

3.1 Content Conformance

3.2 Processor Conformance

3.2.1 Generic Processor Conformance

3.2.2 Transformation Processor Conformance

3.2.3 Presentation Processor Conformance

3.3 Claims

4 Document Types

4.1 DFXP Content

5 Vocabulary

5.1 Namespaces

5.2 Profiles

5.3 Catalog

5.3.1 Core Catalog

5.3.2 Extension Catalog

6 Parameters

6.1 Parameter Element Vocabulary

6.1.1 ttp:profile

6.1.2 ttp:features

6.1.3 ttp:feature

6.1.4 ttp:extensions

6.1.5 ttp:extension

6.2 Parameter Attribute Vocabulary

6.2.1 ttp:cellResolution

6.2.2 ttp:clockMode

6.2.3 ttp: dropMode

6.2.4 ttp:frameRate

6.2.4 6.2.5 ttp:frameRateMultiplier

6.2.5 6.2.6 ttp:markerMode

6.2.6 6.2.7 ttp:pixelAspectRatio

6.2.7 6.2.8 ttp:profile

6.2.10 ttp:tickRate

6.2.11 ttp:timeBase

7 Content

7.1 Content Element Vocabulary

7.1.1 tt

7.1.2 head

7.1.3 body

7.1.4 div

7.1.5 p

7.1.6 span

7.1.7 br

7.2 Content Attribute Vocabulary

7.2.1 xml:id

7.2.2 xml:lang

7.2.3 xml:space

8 Styling

8.1 Styling Element Vocabulary

8.1.1 styling

8.1.2 style

8.2 Styling Attribute Vocabulary

8.2.1 style

8.2.2 tts:backgroundColor

8.2.3 tts:color

8.2.4 tts:direction

8.2.5 tts:display

8.2.6 tts:displayAlign

8.2.7 tts:dynamicFlow

8.2.8 tts:extent

8.2.9 tts:fontFamily

8.2.10 tts:fontSize

8.2.11 tts:fontStyle

8.2.12 tts:fontWeight

8.2.13 tts:lineHeight

8.2.14 tts:opacity

8.2.15 tts:origin

8.2.16 tts:overflow