Synchronized Multimedia Integration Language (SMIL 2.0)

W3C Proposed Edited Recommendation 05 November 2004

This version:: http://www.w3.org/TR/2004/PER-SMIL2-20041105/
Latest SMIL 2 version:: http://www.w3.org/TR/SMIL2/
Latest SMIL Recommendation:: http://www.w3.org/TR/SMIL/
Previous version:: http://www.w3.org/TR/2001/REC-smil20-20010807/
Editors:: Jeff Ayars (RealNetworks), Dick Bulterman (Oratrix), Aaron Cohen (Intel), Ken Day (Macromedia), Erik Hodge (RealNetworks), Philipp Hoschka (W3C), Eric Hyche (RealNetworks), Muriel Jourdan (INRIA), Michelle Kim (IBM), Kenichi Kubota (Panasonic), Rob Lanphier (RealNetworks), Nabil Layaïda (INRIA), Thierry Michel (W3C), Debbie Newman (Microsoft), Jacco van Ossenbruggen (CWI), Lloyd Rutledge (CWI), Bridie Saccocio (RealNetworks), Patrick Schmitz (Microsoft), Warner ten Kate (Philips).; Thierry Michel (W3C) - Proposed Edited Recommendation version.

This document is also available in these non-normative formats: single HTML file, zip archive.

This document specifies the second version of the Synchronized Multimedia Integration Language (SMIL, pronounced "smile"). SMIL 2.0 has the following two design goals:

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 and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This is a W3C Proposed Edited Recommendation, a revised edition of the Synchronized Multimedia Integration Language (SMIL) 2.0.
It is here made available for review by W3C members and other interested parties. Note that a Candidate Recommendation draft has not been deemed necessary by the Working Group, as there are no substantial implementation issues arising as a result of this edition, which aims only to incorporate the published corrigenda to the first edition.
If this document is approved as a W3C Recommendation, it will supersede the 07 August 2001 version of the the SMIL 2.0 Recommendation.

Please send comments on this Proposed Edited Recommendation to www-smil@w3.org, including

2E
PER

in the subject line, no later than 05 December 2004.
Publication as a Proposed Edited Recommendation does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This second edition of SMIL 2.0 is not a new version, it merely incorporates the changes dictated by the corrections to errors found in the first edition as agreed by the SYMM Working Group, as a convenience to readers. A separate list of all such corrections is available at http://www.w3.org/2001/07/REC-SMIL20-20010731-errata.
The errata list for this second edition is available at http://www.w3.org/2004/06/EditedREC-SMIL20-errata.

The SMIL 2.0 test suite and Implementation results are publicly released and are intended solely to be used as proof of SMIL 2.0 implementability. It is only a snap shot of the actual implementation behaviors at one moment of time, as these implementations may not be immediately available to the public. The interoperability data is not intended to be used for assessing or grading the performance of any individual implementation.

There are patent disclosures and license commitments associated with the SMIL 2.0 Recommendation, these may be found at the Working Group's public SYMM Patent Statement page in conformance with W3C policy.

The authors of this document are the SYMM Working Group members. Different parts of the document have different editors.
The W3C staff contact for work on SMIL is Thierry MICHEL.

The English version of this specification is the only normative version. Information about translations of this document is available.

Quick Table of Contents

1. About SMIL 2.0
2. The SMIL 2.0 Modules
3. The SMIL 2.0 Animation Modules
4. The SMIL 2.0 Content Control Modules
5. The SMIL 2.0 Layout Modules
6. The SMIL 2.0 Linking Modules
7. The SMIL 2.0 Media Object Modules
8. The SMIL 2.0 Metainformation Module
9. The SMIL 2.0 Structure Module
10. The SMIL 2.0 Timing and Synchronization Module
11. The SMIL 2.0 Time Manipulations Module
12. The SMIL 2.0 Transition Effects Module
13. SMIL 2.0 Language Profile
14. SMIL 2.0 Basic Profile and Scalability Framework
Appendix A. SMIL 2.0 DTDs
Appendix B. SMIL 2.0 Schemas
Appendix C. Index of Elements
Appendix D. Index of Attributes
Appendix E. References

Full Table of Contents

1. About SMIL 2.0
- 1.1 Introduction
  - 1.1.1 Relation to SMIL 1.0
  - 1.1.2 Content of this Recommendation
- 1.2 Acknowledgements
2. The SMIL 2.0 Modules
3. The SMIL 2.0 Animation Modules
4. The SMIL 2.0 Content Control Modules
5. The SMIL 2.0 Layout Modules
6. The SMIL 2.0 Linking Modules
7. The SMIL 2.0 Media Object Modules
8. The SMIL 2.0 Metainformation Module
9. The SMIL 2.0 Structure Module
10. The SMIL 2.0 Timing and Synchronization Module
11. The SMIL 2.0 Time Manipulations Module
- 11.1 Introduction
12. The SMIL 2.0 Transition Effects Module
13. SMIL 2.0 Language Profile
14. SMIL 2.0 Basic Profile and Scalability Framework
Appendix A. SMIL 2.0 DTDs
Appendix B. SMIL 2.0 Schemas
Appendix C. Index of Elements
Appendix D. Index of Attributes
Appendix E. References

1. About SMIL 2.0

1.1 Introduction

This document specifies the second version of the Synchronized Multimedia Integration Language (SMIL, pronounced "smile"). SMIL 2.0 has the following two design goals:

SMIL 2.0 is defined as a set of markup modules, which define the semantics and an XML syntax for certain areas of SMIL functionality.

1.1.1 Relation to SMIL 1.0

SMIL 2.0 deprecates a small amount of SMIL 1.0 syntax in favor of more DOM friendly syntax. Most notable is the change from hyphenated attribute names to mixed case (camel case) attribute names, e.g., clipBegin is introduced in favor of clip-begin. The SMIL 2.0 modules do not require support for these SMIL 1.0 attributes so that integration applications are not burdened with them. SMIL document players, those applications that support playback of "application/smil" documents, and host language conformant document profiles must support the deprecated SMIL 1.0 attribute names as well as the new SMIL 2.0 names.

1.1.2 Content of this Recommendation

This Recommendation is structured as a set of sections, each defining one or more modules:

This Recommendation also defines two profiles that are built using the above SMIL 2.0 modules:

The XHTML+SMIL Profile that appeared in Working Drafts of this Recommendation is published separately, and is not part of the SMIL 2.0 Recommendation. However, one of the implementations used to validate SMIL 2.0 was based on the XHTML+SMIL Profile. All XHTML+SMIL examples in this Recommendation conform to the Profile as of the Working Draft of 07 August 2001. The latest version of this document is also available, see [XHTML+SMIL].

1.2 Acknowledgements

This document has been prepared by the Synchronized Multimedia Working Group (SYMM-WG) of the World Wide Web Consortium. The WG included the following individuals:

2. The SMIL 2.0 Modules

2.1 Introduction

Since the publication of SMIL 1.0 [SMIL10], interest in the integration of SMIL concepts with the HTML, the HyperText Markup Language [HTML4], and other XML languages, has grown. Likewise, the W3C HTML Working Group has specified XHTML, the Extensible HyperText Markup Language [XHTML10], in preparation to subset, extend, and integrate it with other languages. The strategy considered for integrating respective functionality with other XML-based languages is based on the concepts of modularization and profiling [SMIL-MOD], [XMOD].

Modularization is an approach in which markup functionality is specified as a set of modules that contain semantically-related XML elements, attributes, and attribute values. Profiling is the creation of an XML-based language through combining these modules, in order to provide the functionality required by a particular application.

Profiling introduces the ability to tailor an XML-based language to specific needs, e.g. to optimize presentation and interaction for the client's capabilities. Profiling also adds the ability for integrating functionality from other markup languages, releasing the language designer from specifying that functionality. Moreover, it provides for consistency in markup through the use of the same model to incorporate a function. Identical constructs ease authoring, while at the user agent side there is a potential for re-use of code. For example, a scheduler supporting SMIL timing and synchronization functionality could be used for SMIL documents, XHTML+SMIL documents, and SVG documents.

Modularization enables language designers to specify dedicated markup intended for integration with other, existing, language profiles. Examples of specifications intended for such integration are MathML and XForms [MathML], [XFORMS].

Modularization and profiling use the extensibility properties of XML, and related technology like XML namespaces and XML Schema [XML10], [XML-NS], [XSCHEMA].

This part of the SMIL 2.0 specification describes the framework on which SMIL modularization and profiling is based, and specifies the SMIL 2.0 Modules, their identifiers, and the requirements for conformance within this framework.

2.1.1 Modularization and Profiling

The modularization approach used in this specification derives from that set forth in XHTML Modularization [XMOD]. The framework on which SMIL modularization and profiling is based, is informally described here.

A Module is a collection of semantically-related XML elements, attributes, and attribute values that represents a unit of functionality. Modules are defined in coherent sets. This coherency is expressed in that the elements of these modules are associated with the same namespace.

A Language Profile is a combination of modules. Modules are atomic, i.e. they cannot be subset when included in a language profile. Furthermore, a module specification may include a set of integration requirements, to which language profiles that include the module must comply.

Commonly, there is a main language profile that incorporates nearly all the modules associated with a single namespace. For example, the SMIL 2.0 language profile uses most of the SMIL 2.0 modules. Usually, the same name is used to loosely reference both - "SMIL 2.0" in the example. Also, the name "profile" is used to mean "language profile".

Other language profiles can be specified that are subsets of the larger one, or that incorporate a mixture of modules associated with different namespaces. SMIL 2.0 Basic is an example of the first, XHTML+SMIL of the latter.

A special module in a language profile is the so-called Structure Module, in that it contains the root element of the language profile, e.g. <smil> or <html>. Any language profile that incorporates modules associated with a single namespace will include the Structure module associated with that namespace.

Other modules that require special mention are those that characterize the core of the functionality provided by the namespace. This is expressed by the notions of host language and integration set. Both of them relate to a set of conformance requirements for language profiles, which includes the requirement to incorporate at least the core set of modules. The set may be different for a host language and an integration set. A host language must incorporate the Structure module; an integration set need not. There may be other differences as well.

The main purpose of language profile conformance is to enhance interoperability. Preferably, the mandatory modules for host language conformance are defined in such a way that any document interchanged in a conforming language profile