SYMM Working Group Charter

The mission of the SYMM Working Group [SYMM WG] is to continue W3C's work on synchronized multimedia that started with SMIL 1.0, SMIL 2.0. Its main contribution is extending the functionality contained in the current SMIL 2.0 Recommendation. In the event of a conflict between this document and the W3C Process, the W3C Process shall take precedence.

2. Scope

Since SMIL 2.0 has been released, a number of extension proposals have been received by the SYMM Interest Group [SYMM IG]. This section describes the work items to be treated by the Working Group. The Working Group is free to decide that some of the extensions listed below are not worthwhile pursuing, and to potentially develop and evaluate new extension proposals.

2.1 SMIL 2.0 Proposed Edited Recommendation

Revise the current SMIL 2.0 Recommendation to incorporate fixed SMIL 2.0 Errata. This document will be a full re-edition of SMIL 2.0 including normative DTD and Schema (Plan is to issue a Proposed Edited Recommendation).

2.2 SMIL 2.1 for Mobile Devices

SMIL 2.1 version will incorporate features currently in use within the mobile industry, where SMIL is used as the basis of the MMS (Multimedia Messaging) Service. Given the already existing experience with these features, it should not take a lot of time for the WG to come to consensus on these features. Therefore, the SYMM WG plans to release SMIL 2.1 directly as a Last Call Working Draft. This will save time and help to get to Recommendation faster. It will also enable other standard bodies such as 3GPP and OMA to base their MMS-related specifications on W3C's SMIL 2.1 specification.

The SMIL 2.1 version will be build on top of SMIL 2.0. It should only specify new and extended features. Therefore the document should only incorporate new or enhanced functionalities, the revised or extended modules and the revised or extended profile.

2.3 SMIL Future Version

Work on a future version of SMIL will allow the SYMM WG to investigate some of the proposals that have not yet reached wider consensus and for which deployment is less certain at the time of writing. Only proposals with industry consensus on their necessisity should be pursued.
The SYMM WG once done with the SMIL 2.1 for Mobile Devices version, should work on a SMIL Future Version requirement document that lists these work items.

Media Identification and Linking

Mechanism for passing parameters to hyperlink destination: Similar to MediaParam module, we should have a mechanism for passing parameters for linking. This also includes, for example, specifying start time of a destination SMIL file, etc.
Professional Media Clipping : Subframe definition of current SMIL 2.0 seems to have an error to be fixed and in addition professional media may have more variety of time scales/frame rates. Some means should be provided by the next version (see SMIL SUB).
Media Type Casting: Each media type (video, audio, text, ref,..) should have individual meaning and function. (see SMIL SUB).
Media Track Manipulation: To specify individual audio/video track out of a multi-track material (see SMIL SUB).
Visual Area Clipping: To clip out some specific region from full visual area of video material (see SMIL SUB).
Time Container Clipping: To manipulate par/seq elements as media elements (see SMIL SUB).

Media Layout

CSS, Style and Media Filtering: Determine how SMIL handles CSS (and other) style sheets. The proposal is to have SMIL specify that media being integrated can be styled by external style sheet.
Media Time Destination: To place time containers on exact time coordinates with professional time scales/ frame rates (see SMIL SUB)..

Media Manipulation

Visual Effects: alpha blending, visual deformation, color correction (see SMIL SUB).
Text handling: harmonize the different approaches used to style text today. A further idea would be to integrate text directly in SMIL, similar to SVG.

Others

Support for various types of metadata schemas of any type of XML descriptions (e.g. MPEG-7, TV-Anytime, etc, many of which are industry dependent metadata and not in RDF but only in XML. Such metadata must be properly embedded into content descriptions.), (see SMIL SUB).
Metadata Synchronization: Some metadata need not only to be associated with media objects but also to be synchronized along with the timeline of media objects. Such metadata may be considered as a kind of media objects itself. This functionality is to provide a means to synchronize metadata streaming objects with other media streaming objects, (see SMIL SUB).
Reconsider the scalability to accommodate evolving modules into scalable profiles.

2.4 Miscellaneous

The Working Group should investigate the potential needs within the industry before addressing the following areas of functionality:

Note: The SYMM WG may also take over the results of the Timed Text Working Group [TTWG] if that group terminates without having finished its work.

3. Deliverables

4. Duration

This Working Group is scheduled to last for 24 months, from May 2004 through May 2006. This includes a six month "life after Recommendation" phase.

5. Success Criteria

6. Milestones

Note that public working drafts will be made available at least once every three months, per W3C Process.

7. Dependencies/Relationship with other W3C Activities

The Working Group has to take into account technologies developed by other groups within W3C, and ask them to review specifications prepared by the SYMM Working Group. At the time the charter was written, the following ongoing W3C activities are concerned:

8. Coordination with External Groups and Standard bodies

Outside W3C, a number of groups are working technologies relevant for the SYMM WG.

9. Membership, Participation and Resources

9.1 Membership

To become a member of the SYMM Working Group, a representative of a W3C Member organization must be nominated by their Advisory Committee Representative (please send email to the Working Group chair and the W3C team contact). The nomination must include explicit agreement to this charter, including its goals, a Patent disclosure and the level of effort required of the representative.
Membership is also open to invited experts from the community, as per W3C process.
Participation is expected to consume at least one day per week of each Working Group member's time.

9.2 Resources

The SYMM WG is chaired by Yoshihisa Gonno (Sony) and Guido Grassel (Nokia).
The W3C team contact for this working Group is Thierry Michel.

9.3 W3C Team Involvement

The W3C team will provide a team contact whose task are described in the document "Role of the Team Contact". W3C team members are expected to adopt the same requirements for meeting attendance, timely response and information disclosure as are required of W3C Members. 30% of the W3C team contact's time is expected to be devoted to the SYMM Working Group.

10. Communication, Meetings, and Logistics

10.1 Email Communication

The SYMM Working Group utilizes a member-confidential mailing list <symm@w3.org> and a public mailing list <www-smil@w3.org>.

10.2 Group Home Page

The Working Group has a home page that records the history of the group, provides access to the archives, meeting minutes, updated schedule of deliverables, membership list, and relevant documents and resources. The page is maintained by the Chair (s) in collaboration with the W3C team contact.

10.3 Telephone Meetings

A one to two hour Working Group phone conference is held every week. When necessary to meet agreed-upon deadlines, phone conferences may be held twice a week.

10.4 Face-to-Face Meetings

Participation in face-to-face meetings is limited to SYMM Working Group members. Decisions may be taken in face-to-face meetings but must be announced on the Working Group mailing list.
The Chair (s) makes Working Group meeting dates and locations available to the group at least eight weeks before the meeting, per W3C Process.

11. Patent Policy

The current Working Group is operating under the W3C Patent Policy (05 February 2004 Version). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis.

12. Related Documents

For questions on this document, please contact:: Thierry Michel <tmichel@w3.org> (last modified on $Date: 2006/06/01 18:58:52 $)

"Synchronized Multimedia" Working Group (SYMM WG) Charter

Table of Contents

1. Mission Statement