W3C W3C Member Submission

TTML Text and Image Profiles for Internet Media Subtitles and Captions

W3C Member Submission

This version:
http://www.w3.org/submissions/2013/SUBM-ttml-ww-profiles-20130607/
Latest published version:
http://www.w3.org/submissions/ttml-ww-profiles/
Previous version:
Editor:
Pierre Lemieux,

Copyright © 2013 Motion Picture Laboratories, Inc. Derived from the Common File Format & Media Formats Specification 1.0.6 and Common File Format Timed Text XML Schemas 1.0.6 posted at http://www.uvvuwiki.com, © Digital Entertainment Content Ecosystem (DECE) LLC and used with permission.This document is available under the W3C Document License. See the W3C Intellectual Rights Notice and Legal Disclaimersfor additional information.

Abstract

This submission specifies two profiles of the Timed Text Markup Language (TTML) Version 2.0: a text-only profile and an image-only profile. These profiles are intended to be used across subtitle and caption delivery applications worldwide, thereby simplifying interoperability, consistent rendering and conversion to other subtitling and captioning formats.

Both profiles are based on the Common File Format & Media Formats Specification (CFF) developed by Digital Entertainment Content Ecosystem (DECE), and benefit from the technical consensus, conformance testing and implementation experience gathered there. The text profile is intended as a superset of SDP-US, which is a subset of CFF. The image profile extends a subset of TTML with SMPTE Timed Text (SMPTE-TT) image support.

DECE is an industry forum with more than 80 members across the content and consumer electronics communities.

Status of This Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications can be found in the W3C technical reports index at http://www.w3.org/TR/.

By publishing this document, W3C acknowledges that the Submitting Members have made a formal Submission request to W3C for discussion. Publication of this document by W3C indicates no endorsement of its content by W3C, nor that W3C has, is, or will be allocating any resources to the issues addressed by it. This document is not the product of a chartered W3C group, but is published as potential input to the W3C Process. A W3C Team Comment has been published in conjunction with this Member Submission. Publication of acknowledged Member Submissions at the W3C site is one of the benefits of W3C Membership. Please consult the requirements associated with Member Submissions of section 3.3 of the W3C Patent Policy. Please consult the complete list of acknowledged W3C Member Submissions.

Table of Contents

1. Scope

This document specifies two profiles of [TTML2]: a text-only profile and an image-only profile. These profiles are intended for subtitle and caption delivery worldwide, including dialog language translation, content description, captions for deaf and hard of hearing, etc.

2. Conformance

As well as sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative.

The keywords MUST, MUST NOT, SHALL, SHALL NOT, REQUIRED, SHOULD, SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL in this specification are to be interpreted as described in [RFC2119].

A subtitle document SHALL conform to a profile defined herein if it meets all normative provisions associated with the profile.

A TTML presentation processor SHALL conform to a profile if it is capable of presenting any subtitle document conforming to the profile, i.e. if it implements all features and provisions of the profile

3. Profiles

3.1 General

A subtitle document SHALL NOT conform to the Text and Image Profiles simultaneously.

3.2 Text Profile

A subtitle document conforming to the Text Profile SHALL conform to Sections 4. Common Constraints and 5. Text Profile Constraints.

3.3 Image Profile

A subtitle document conforming to the Image Profile SHALL conform to Sections 4. Common Constraints and 6. Image Profile Constraints.

4. Common Constraints

4.1 Document Encoding

A subtitle document SHALL use UTF-8 character encoding as specified in [UNICODE].

4.3 Language

All instances of the xml:lang attribute within a subtitle document SHALL have identical values.

Note

xml:lang can have a value of "".

4.4 Region

4.4.1 Presented Region

A region, as defined in [TTML2], SHALL be considered presented in a given intermediate synchronic document if both of the following conditions are true:

  1. tts:opacity is not equal to "0.0" for the region; and

  2. content is selected into the region or tts:showBackground is equal to "always" for the region.

Note

As specified in [TTML2], the initial value of tts:opacity is "1.0" and the default value of tts:showBackground is "always".

4.4.2 Dimensions and Position

All regions SHALL be entirely contained within the root container.

No two regions presented in a given intermediate synchronic document SHALL overlap

4.4.3 Maximum number

The number of presented regions in a given intermediate synchronic document SHALL be smaller than or equal to 4.

4.5 Hypothetical Render Model

Any sequence of consecutive intermediate synchronic documents SHALL be reproducible without error by the Hypothetical Render Model specified in Section 4.5 Hypothetical Render Model.

4.6 Features

Feature Provisions
#animation MAY be used.
#cellResolution SHALL NOT be used.
#clockMode SHALL NOT be used.
#content MAY be used.
#core MAY be used.
#display-block MAY be used.
#display-inline MAY be used.
#display-region MAY be used.
#display MAY be used.
#dropMode SHALL NOT be used.
#extent-region MAY be used. The tts:extent attribute SHALL be present on all region elements.
#extent-root MAY be used. If the document includes any length value that uses the px expression, tts:extent SHALL be present on the tt element.
#extent MAY be used.
#frameRate If the document includes any time expression that uses the frame field, the ttp:frameRate attribute SHALL be present on the tt element.
#frameRateMultiplier MAY be used.
#layout MAY be used.
#length-cell SHALL NOT be used.
#length-integer MAY be used.
#length-negative SHALL NOT be used.
#length-percentage MAY be used.
#length-pixel MAY be used.
#length-positive MAY be used.
#length-real MAY be used.
#length MAY be used.
#markerMode SHALL NOT be used.
#metadata MAY be used.
#opacity MAY be used.
#origin MAY be used.
#overflow SHALL NOT be used.
#pixelAspectRatio SHALL NOT be used.
#presentation MAY be used.
#profile MAY be used.
#showBackground MAY be used.
#structure MAY be used.
#styling-chained MAY be used.
#styling-inheritance-content MAY be used.
#styling-inheritance-region MAY be used.
#styling-inline MAY be used.
#styling-nested MAY be used.
#styling-referential MAY be used.
#styling MAY be used.
#subFrameRate SHALL NOT be used.
#tickRate MAY be used. ttp:tickRate SHALL be present on the tt element.
#timeBase-clock SHALL NOT be used.
#timeBase-media SHALL be used. ttp:timeBase SHALL be present on the tt element and SHALL be equal to "media".
#timeBase-smpte SHALL NOT be used.
#time-clock-with-frames MAY be used.
#time-clock MAY be used.
#time-offset-with-frames MAY be used.
#time-offset-with-ticks MAY be used.
#time-offset MAY be used.
#timeBase-media MAY be used.
#timeContainer MAY be used.
#timing MAY be used. The same syntax of #clock-time or #offset-time SHOULD be used throughout the subtitle document.
#transformation MAY be used.
#unicodeBidi MAY be used.
#visibility-block MAY be used.
#visibility-inline MAY be used.
#visibility-region MAY be used.
#visibility MAY be used.
#writingMode-horizontal-lr MAY be used.
#writingMode-horizontal-rl MAY be used.
#writingMode-horizontal MAY be used.
#writingMode MAY be used.
#zIndex MAY be used.
#aspectRatio MAY be used.
#forcedDisplay MAY be used.
Note

See ISSUE-230 for a description of #forcedDisplay

Note

This initial values specified for tts:color, tts:displayAlign and tts:textAlign are those specified by [ST2052-1].

Note

As specified in [TTML2], a #time-offset-with-frames expression is translated to a media time M according to M = 3600 · hours + 60 · minutes + seconds + (frames ÷ (ttp:frameRateMultiplier · ttp:frameRate)).

5. Text Profile Constraints

5.1 Document Conformance

A subtitle document conforming to the Text Profile SHALL be designated by the document conformance designator specified below.

http://www.w3.org/ns/ttml/profile/imsc-text
Note

The ttp:profile mechanism of TTML 1.0 allows a document to indicate the profile(s) that a processor SHALL support in order to process the document. This mechanism cannot be used to indicate that a processor implementing any of the referenced profiles can process the document. The document conformance concept introduced below extends the TTML 1.0 ttp:profile mechanism by allowing a document to signal that it conforms to a specified set of normative provisions.

5.2 Features

Note

The following assumes, but does not require, the porting of the [ST2052-1] #backgroundImage, #backgroundImageHorizontal, #backgroundImageVertical and #image features to [TTML2].

Feature Provisions
#backgroundColor-block MAY be used.
#backgroundColor-inline MAY be used.
#backgroundColor-region MAY be used.
#backgroundColor MAY be used.
#backgroundImage SHALL NOT be used.
#backgroundImageHorizontal SHALL NOT be used.
#backgroundImageVertical SHALL NOT be used.
#bidi MAY be used.
#color MAY be used. The initial value of tts:color SHALL be "white".
#direction MAY be used.
#displayAlign MAY be used. The initial value of tts:displayAlign SHALL be "after".
#extent-region The tts:extent attribute when applied to a region element SHALL use px units or "percentage" representation, and SHALL NOT use em units.
#fontFamily-generic MAY be used.
#fontFamily-non-generic MAY be used.
#fontFamily MAY be used.
#fontSize-anamorphic SHALL NOT be used.
#fontSize-isomorphic MAY be used.
#fontSize MAY be used.
#fontStyle-italic MAY be used.
#fontStyle-oblique MAY be used.
#fontStyle MAY be used.
#fontWeight-bold MAY be used.
#fontWeight MAY be used.
#image SHALL NOT be used.
#length-em MAY be used.
#lineBreak-uax14 MAY be used.
#lineHeight MAY be used.
#nested-div MAY be used.
#nested-span MAY be used.
#origin The tts:origin attribute SHALL use px units or "percentage" representation, and SHALL NOT use em units.
#padding-1 MAY be used.
#padding-2 MAY be used.
#padding-3 MAY be used.
#padding-4 MAY be used.
#padding MAY be used.
#textAlign-absolute MAY be used.
#textAlign-relative MAY be used.
#textAlign MAY be used. The initial value of tts:textAlign SHALL be "center".
#textDecoration-over MAY be used.
#textDecoration-through MAY be used.
#textDecoration-under MAY be used.
#textDecoration MAY be used.
#textOutline-blurred SHALL NOT be used.
#textOutline-unblurred MAY be used.
#textOutline MAY be used. If specified, the border thickness SHALL be 10% or less than the associated font size.
#wrapOption MAY be used.
#writingMode-vertical MAY be used.

6. Image Profile Constraints

6.1 Document Conformance

The Image Profile SHALL be designated by the document conformance designator specified below:

http://www.w3.org/ns/ttml/profile/imsc-image
Note

The ttp:profile mechanism of TTML 1.0 allows a document to indicate the profile(s) that a processor SHALL support in order to process the document. This mechanism cannot be used to indicate that a processor implementing any of the referenced profiles can process the document. The document conformance concept introduced below extends the TTML 1.0 ttp:profile mechanism by allowing a document to signal that it conforms to a specified set of normative provisions.

6.2 Features

Note

The following assumes, but does not require, the porting of the [ST2052-1] #backgroundImage, #backgroundImageHorizontal, #backgroundImageVertical and #image features to [TTML2].

Feature Provisions
#backgroundImage MAY be used. The backgroundImage attribute SHALL reference a complete image that conforms to the PNG image coding as specified in Sections 7.1.1.3 and 15.1 of [MHP].
If a pHYs chunk is present, it SHALL indicate square pixels. Note: If no pixel aspect ratio is carried, the default of square pixels will be assumed.
#backgroundImageHorizontal SHALL NOT be used. #backgroundImage remains available for use.
#backgroundImageVertical SHALL NOT be used. #backgroundImage remains available for use.
#bidi SHALL NOT be used.
#color SHALL NOT be used.
#content The p, span and br elements SHALL NOT be present.
#direction SHALL NOT be used.
#displayAlign SHALL NOT be used.
#extent-region If a tts:backgroundImage attribute is applied to a region, the width and height of the region extent SHALL be present and SHALL be equal to the width and height of the image source referenced by the tts:backgroundImage.
#fontFamily SHALL NOT be used.
#fontSize SHALL NOT be used.
#fontStyle SHALL NOT be used.
#fontWeight SHALL NOT be used.
#image SHALL NOT be used.
#length-em SHALL NOT be used.
#lineBreak-uax14 SHALL NOT be used.
#lineHeight SHALL NOT be used.
#nested-div SHALL NOT be used.
#nested-span SHALL NOT be used.
#padding SHALL NOT be used.
#textAlign SHALL NOT be used.
#textDecoration SHALL NOT be used.
#textOutline SHALL NOT be used.
#wrapOption SHALL NOT be used.
#writingMode-vertical SHALL NOT be used.

7. Hypothetical Render Model

7.1 Overview

This Section specifies the Hypothetical Render Model illustrated in Fig. 1 Hypothetical Render Model .

The purpose of the model is to limit subtitle document complexity. It is not however intended to serve as basis for implementation. For instance, while the model defines a glyph buffer for the purpose of limiting the number of glyphs displayed at any given point in time, it does not require an implementation to implement such a buffer.

Hypothetical Render Model
Fig. 1 Hypothetical Render Model

The model operates on successive intermediate synchronic documents obtained from an input subtitle document, and uses a simple double buffering model: while an intermediate synchronic document En is being painted into Presentation Buffer Pn (the "front buffer" of the model), the previous intermediate synchronic document En-1 is available for display in Presentation Buffer Pn-1 (the "back buffer" of the model).

The model specifies an (hypothetical) time required for completely painting an intermediate synchronic document as a proxy for complexity. Painting includes drawing region backgrounds, rendering and copying glyphs, and decoding and copying images. Complexity is then limited by requiring that painting of intermediate synchronic document En completes before the end of intermediate synchronic document En-1.

Whenever applicable, constraints are specified relative to root container dimensions, allowing subtitle sequences to be authored independently of related video object resolution.

To enables scenarios where the same glyphs are used in multiple successive intermediate synchronic documents, e.g. to convey a CEA-608/708-style roll-up (see [CEA-608] and [CEA-708]), the Glyph Buffers Gn and Gn-1 store rendered glyphs across intermediate synchronic documents, allowing glyphs to be copied into the Presentation Buffer instead of rendered, a more costly operation.

Similarly, Decoded Image Buffers Dn and Dn-1 store decoded images across intermediate synchronic documents, allowing images to be copied into the Presentation Buffer instead of decoded.

7.2 Model

7.2.1 General

The Presentation Compositor SHALL render in Presentation Buffer Pn each successive intermediate synchronic document En using the following steps in order:
  1. clear the pixels, except for the first intermediate synchronic document E0 for the which the pixels of P0 SHALL be assumed to have been cleared;
  2. paint, according to stacking order, all background pixels for each region;
  3. paint all pixels for background colors associated with text or image subtitle content; and
  4. paint the text or image subtitle content.

The Presentation Compositor SHALL start rendering En:

  • at the presentation time of E0 minus Initial Painting Delay (IPD), if n = 0
  • at the presentation time of En-1, if n > 0

The duration DUR(En) for painting an intermediate synchronic document En in the Presentation Buffer Pn SHALL be:

DUR(En) = S(En) / BDraw + DURT(En) + DURI(En)

Where:

  • S(En) is the total normalized drawing area for intermediate synchronic document En, as specified in 7.2.2 Paint Regions
  • BDraw is the normalized background drawing performance factor.
  • DURT(En) is the duration, in seconds, for painting the text subtitle content for intermediate synchronic document En, as specified in Section 7.2.4 Paint Text
  • DURI(En) is the duration, in seconds, for painting the image subtitle content for intermediate synchronic document En, as specified in Section 7.2.3 Paint Images

The contents of the Presentation Buffer Pn SHALL be transferred instantaneously to Presentation Buffer Pn-1 at the presentation time of intermediate synchronic document En, making the latter available for display.

Note

It is possible for the contents of Presentation Buffer Pn-1 to never be displayed. This can happen if Presentation Buffer Pn is copied twice to Presentation Buffer Pn-1 between two consecutive video frame boundaries of the related video object.

It SHALL be an error for the Presentation Compositor to fail to complete painting pixels for En before the presentation time of En.

Unless specified otherwise, the following table SHALL specify values for IPD and BDraw.

Parameter Initial value
Initial Painting Delay (IPD) 1 s
Normalized background drawing performance factor (BDraw) 12 s-1
Note

BDraw effectively sets a limit on fillings regions - for example, assuming that the root container is ultimately rendered at 1920×1080 resolution, a BDraw of 12 s-1 would correspond to a fill rate of 1920×1080×12/s=23.7×220pixels s-1.

Note

IPD effectively sets a limit on the complexity of any given intermediate synchronic document.

7.2.2 Paint Regions

The total normalized drawing area S(En) for intermediate synchronic document En SHALL be

S(En) = CLEAR(En) + PAINT(En )

where CLEAR(E0) = 0 and CLEAR(En | n > 0) = 1, i.e. the root container in its entirety.

Note

To ensure consistency of the Presentation Buffer, a new intermediate synchronic document requires clearing of the root container.

PAINT(En) SHALL be the normalized area to be painted for all regions that are used in intermediate synchronic document En according to

PAINT(En) = ∑Ri∈Rp SIZE(Ri) ∙ NBG(Ri)

where R_p SHALL be the set of regions presented in the intermediate synchronic document En – see Section 4.4.1 Presented Region for the definition of presented region.

NSIZE(Ri) SHALL be given by:

NSIZE(Ri) = (width of Ri ∙ height of Ri ) ÷ (root container height ∙ root container width)

NBG(Ri) SHALL be the total number of tts:backgroundColor attributes associated with the given region Ri in the intermediate synchronic document. A tts:backgroundColor attribute is associated with a region when it is explicitly specified (either as an attribute in the element, or by reference to a declared style) in the following circumstances:

  • It is specified on the region layout element that defines the region.
  • It is specified on a div, p, span or br content element that is to be flowed into the region for presentation in the intermediate synchronic document (see [TTML2] for more details on when a content element is followed into a region).
  • It is specified on a set animation element that is to be applied to content elements that are to be flowed into the region for presentation in the intermediate synchronic document (see [TTML2] for more details on when a set animation element is applied to content elements).

Even if a specified tts:backgroundColor is the same as specified on the nearest ancestor content element or animation element, specifying any tts:backgroundColor SHALL require an additional fill operation for all region pixels.

7.2.3 Paint Images

The Presentation Compositor SHALL paint into the Presentation Buffer Pn all visible pixels of presented images of intermediate synchronic document En.

A presented image SHALL be a div element with a smpte:backgroundImage attribute that is contained within a presented region.

For each presented image, the Presentation Compositor SHALL either:

  • if an identical image is present in Decoded Image Buffer Dn, copy the image from Decoded Image Buffer Dn to the Presentation Buffer Pn using the Image Copier; or
  • if an identical image is present in Decoded Image Buffer Dn-1, i.e. an identical image was present in intermediate synchronic document En-1, copy using the Image Copier the glyph from Decoded Image Buffer Dn-1 to both the Decoded Image Buffer Dn and the Presentation Buffer Pn; or
  • Otherwise, decode the image using the Image Decoder the image into the Presentation Buffer Pn and Decoded Image Buffer Dn.

Two images SHALL be identical if and only if they reference the same encoded image source.

The duration DURI(En) for painting images of an intermediate synchronic document En in the Presentation Buffer SHALL be as follows:

DURI(En) = ∑Ii ∈ Ic NRGA(Ii) / ICpy + ∑Ij ∈ Id NSIZ(Ij) / IDec

where

  • Ic is the set of images copied when painting intermediate synchronic document En
  • Id is the set of images decoded when painting intermediate synchronic document En
  • IDec is the image decoding rate
  • ICpy is the normalized image copy performance factor.

NRGA(Ii) is the Normalized Image Area of presented image Ii and SHALL be equal to:

NRGA(Ii)= (width of Ii ) ∙ height of Ii ) ÷ ( root container height ∙ root container width )

NSIZ(Ii) SHALL be the number of pixels of presented image Ii.

The contents of the Decoded Image Buffer Dn SHALL be transferred instantaneously to Decoded Image Buffer Dn-1 at the presentation time of intermediate synchronic document En.

The total size occupied by images stored in Decoded Image Buffers Dn or Dn-1 SHALL be the sum of their Normalized Image Area.

The size of Decoded Image Buffers Dn or Dn-1 SHALL be the Normalized Decoded Image Buffer Size (NDIBS).

Unless specified otherwise, the following table SHALL specify ICpy, Idec, and NDBIS.

Parameter Initial value
Normalized image copy performance factor (ICpy) 6
Image Decoding rate (Idec) 1 × 220 pixels s-1
Normalized Decoded Image Buffer Size (NDIBS) 0.9885

7.2.4 Paint Text

For each glyph displayed in intermediate synchronic document En, the Presentation Compositor SHALL:

  • if an identical glyph is present in Glyph Buffer Gn, copy the glyph from Glyph Buffer Gn to the Presentation Buffer Pn using the Glyph Copier; or
  • if an identical glyph is present in Glyph Buffer Gn-1, i.e. an identical glyph was present in intermediate synchronic document En-1, copy using the Glyph Copier the glyph from Glyph Buffer Gn-1 to both the Glyph Buffer Gn and the Presentation Buffer Pn; or
  • Otherwise render using the Glyph Renderer the glyph into the Presentation Buffer Pn and Glyph Buffer Gn using the corresponding style information.

Two glyphs are identical if and only if the following [TTML2] styles are identical:

  • tts:color
  • tts:fontFamily
  • tts:fontSize
  • tts:fontStyle
  • tts:fontWeight
  • tts:textDecoration
  • tts:textOutline
Example of Presentation Compositor Behavior for Text Rendering
Fig. 2 Example of Presentation Compositor Behavior for Text Rendering

The duration DURT(En) for painting the text of an intermediate synchronic document En in the Presentation Buffer is as follows:

DURT(En) = ∑Gi ∈ Gr NRGA(Gi) / Ren(Gi) + ∑Gj ∈ Gc NRGA(Gj) / GCpy

Where:

  • Gr is the set of glyphs rendered into the Presentation Buffer Pn using the Glyph Renderer in intermediate synchronic document En.
  • Gc is the set of glyphs copied to the Presentation Buffer Pn using the Glyph Copier in intermediate synchronic document En.
  • Ren(Gi) is the text rendering performance factor glyph Gi
  • GCpy is the normalized glyph copy performance factor

Gr and Gc SHALL include only glyphs in presented regions and SHALL NOT include a [UNICODE] Code Point if it does not result in a change to presentation, e.g. the Code Point is ignored.

The Normalized Rendered Glyph Area NRGA(Gi) of a glyph Gi SHALL be equal to:

NRGA(Gi)= (fontSize of Gi as percentage of root container height)2

The contents of the Glyph Buffer Gn SHALL be copied instantaneously to Glyph Buffer Gn-1 at the presentation time of intermediate synchronic document En.

The total size occupied by the glyphs stored in Glyph Buffers Gn or Gn-1 SHALL be the sum of their Normalized Rendered Glyph Area.

The size of Glyph Buffers Gn and Gn-1 SHALL be the Normalized Glyph Buffer Size (NGBS).

Unless specified otherwise, the following table SHALL specify GCpy, Ren and NGBS, and SHALL apply to all supported font styles (including provision of outline border).

Parameter Initial value
Normalized glyph copy performance factor (GCpy) 12
Text rendering performance factor Ren(Gi if Gi is not a CJK Unified Ideograph as specified in [UNICODE]. 1.2
Text rendering performance factor Ren(Gi) if Gi is a CJK Unified Ideograph as specified in [UNICODE]. 0.6
Normalized Glyph Buffer Size (NGBS) 1
Note

NRGA(Gi) does not take into account glyph decorations (e.g. underline), glyph effects (e.g. outline) or actual glyph aspect ratio. An implementation can determine an actual buffer size needs based on worst-case glyph size complexity.

B. Typical Practice for Subtitles per Region (Informative)

This section is non-normative.

The following table summarizes subtitle languages commonly used in the listed regions. The Language Tag is as specified in RFC 5646.

Region Subtitle Languages (Language Tag)
ALL (worldwide) English ("en")
America (North)
ALL French ("fr") [Québécois ("fr-CA") or Parisian ("fr-FR")]
United States Spanish ("es") [Latin American ("es-419")]
America (Central and South)
ALL Spanish ("es") [Latin American ("es-419")]
Brazil Portuguese ("pt") [Brazilian ("pt-BR")]
Asia, Middle East, and Africa
China Chinese ("zh") [Simplified Mandarin ("zh-cmn-Hans")]
Egypt Arabic ("ar")
Hong Kong Chinese ("zh") [Cantonese ("zh-yue")]
India Hindi ("hi")
Tamil ("ta")
Telugu ("te")
Indonesia Indonesian ("id")
Israel Hebrew ("he")
Japan Japanese ("ja")
Kazakhstan Kazakh ("kk")
Malaysia Standard Malay ("zsm")
South Korea Korean ("ko")
Taiwan Chinese ("zh") [Traditional Mandarin ("zh-cmn-Hant")]
Thailand Thai ("th")
Vietnam Vietnamese ("vi")
Europe
Benelux (Belgium, Netherlands, and Luxembourg) French ("fr") [Parisian ("fr-FR")]
Dutch/Flemish ("nl")
Denmark Danish ("da")
Finland Finnish ("fi")
France French ("fr") [Parisian ("fr-FR")]
Arabic ("ar")
Germany German ("de")
Turkish ("tr")
Italy Italian ("it")
Norway Norwegian ("no")
Spain Spanish ("sp") [Castilian ("sp-ES")]
Catalan ("ca")
Sweden Swedish ("sv")
Switzerland French ("fr") ["fr-CH" or "fr-FR"]
German ("de") ["de-CH"]
Italian ("it") ["it-CH"]
Albania Albanian ("sq")
Bulgaria Bulgarian ("bg")
Croatia Croatian ("hr")
Czech Republic Czech ("cs")
Estonia Estonian ("et")
Greece Greek ("el")
Hungary Hungarian ("hu")
Iceland Icelandic ("is")
Latvia Latvian ("lv")
Lithuania Lithuanian ("lt")
Macedonia Macedonian ("mk")
Poland Polish ("pl")
Portugal Portuguese ("pt") [Iberian ("pt-PT")]
Romania Romanian ("ro")
Russia Russian ("ru")
Serbia Serbian ("sr")
Slovakia Slovak ("sk")
Slovenia Slovenian ("sl")
Turkey Turkish ("tr")
Ukraine Ukrainian ("uk")

C. Schema

TBD

D. References

D.1 Normative references

[MHP]
ETSI TS 101 812 V1.3.1, Digital Video Broadcasting (DVB); Multimedia Home
[RFC2119]
S. Bradner. Key words for use in RFCs to Indicate Requirement Levels. March 1997. Internet RFC 2119. URL: http://www.ietf.org/rfc/rfc2119.txt
[TTML2]
World Wide Web Consortium (W3C). Timed Text Markup Language (TTML) 2.0.
[UNICODE]
The Unicode Standard. URL: http://www.unicode.org/versions/latest/

D.2 Informative references

[CEA-608]
Line-21 Data Services, ANSI/CEA Standard.
[CEA-708]
Digital Television (DTV) Closed Captioning, ANSI/CEA Standard.
[ST2052-1]
SMPTE ST 2052-1, Timed Text Format (SMPTE-TT)