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.
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.
SMIL 2.1 should comprise the following functionality:
Tiling images within a region
Simple Alignment of content within a region
Audio Effects: Audio Level Control, Audio Transition effects. Currently
the only way for setting an audio transition is to use AudioLayout and
BasicAnimation modules together. Audio specific transition effects should
be incorporated more directly, similar to video transition effects, (see
SMIL
SUB).
Multi Object Transitions: The ability to apply uniform visual
transitions to screen space displaying multiple media objects. Currently,
a transition can only apply to a single media object. We would like to be
able to, for example, have a wipe go across a montage of different
images. Multi object transitions would allow to apply audio/visual
effects to par/seq element as a whole, (see SMIL
SUB).
Unified style definition for both layout and media, "style" attribute:
The current SMIL specification is capable of defining layout in the CSS
manner (type attribute for layout element). Styling is also required for
media objects. One solution would be to incorporate a style attribute to
the media object elements. (see SMIL
SUB).
The Working Group will investigate revisions to the SMIL 2.0 Basic
Profile based on the experience gained with SMIL profiles within the
mobile industry.
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.
Potential work items include:
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:
Release the XMMF draft: External Media Markers
for SMIL 2.0 as a Working Group NOTE.
This draft proposes an XML-based syntax to define a set of IDs and a
time-code syntax for referencing either a single frame/sample in a media
object or a ranges of frames/samples.
Design a DOM for synchronized multimedia documents. In addition to
functions from DOM level 1, 2 and 3, this Working Group should design a
higher level "convenience" interface that is specific to the SMIL.
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.
A tentative schedule of face-to-face meetings and deliverables is
given here:
April 2004
SYMM WG starts.
May 2004
First SYMM WG f2f meeting scheduled on May 12th and 13th hosted by
CWI in Amsterdam.
June 2004
Release a SMIL 2.0 edition as Proposed Edited Recommendation
July 2004
First Working Draft and Last Call of SMIL 2.1
September 2004
SYMM WG f2f meeting
Create "disposition of comments" document for SMIL 2.1
October 2004
Advance SMIL 2.1 to Candidate Recommendation
Provide a Test suite for SMIL 2.1
Interoperability testing of SMIL 2.1 implementations with test
suite.
November 2004
Advance SMIL 2.1 to Proposed Recommendation
December 2004
SYMM WG f2f meeting
SMIL future version Working Draft first publication
SMIL 2.1 version becomes a W3C Recommendation.
March 2005
SYMM WG f2f meeting
SMIL future version Working Draft second publication.
June 2005
SYMM WG f2f meeting
Last Call Working Draft of SMIL future version
September 2005
SYMM WG f2f meeting
Create "disposition of comments" document for SMIL future version Last
Call comments
Provide a final summary of patent statements for SMIL future
version.
October 2005
Advance SMIL future version to Candidate Recommendation.
November 2005
SYMM WG f2f meeting
January 2006
Provide a Test suite for SMIL future version
February 2006
Interoperability testing of SMIL extensions implementations with test
suite.
March 2006
SMIL future version moves to Proposed Recommendation.
April 2006
SMIL future version becomes a W3C Recommendation.
May 2006
SYMM WG ends.
Note that public working drafts will be made available at least once every
three months, per W3C
Process.
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:
The Hypertext Coordination Group has the responsibility for ensuring
that reviews between Working Groups are planned and carried out so as
to meet requirements for deliverables and deadlines. The Hypertext
Coordination Group includes representatives for the XML Coordination
Group and for the Web Accessibility Initiative, as well as the Working
Groups in the Interaction Domain.
The Working Group cooperates with the TT WG to ensure that SMIL meets
the requirements of this group and for proper integration of timed text
into SMIL.
The Working Group cooperates with the DI WG to ensure that SMIL meets
the requirements for device independent access, e.g. to ensure that the
format is usable both on mobile devices and PCs.
The Working Group coordinates with the MMI WG to ensure that SMIL
meets the requirements for a range of modalities including speech, pen
and keypads. The Working Group will work with the MMI WG to look into:
the role of SMIL as a host language for a range of modalities
including speech, pen and keypads. The goal is to combine a number
of different markup modules into a language profile.
the use of the SMIL timing model as part of interaction
management, e.g. for fine grained control over timing
the extension of the SMIL switch element and test attributes into
a more flexible solution based upon the MMI WG's work on an object
model framework for properties relating to device capabilities,
device configuration, user preferences and environmental conditions
(e.g. low battery alert).
The Working Group ensures that SMIL meets the general Web
architecture of the TAG and helps coordinate cross-technology
architecture developments inside and outside W3C.
Outside W3C, a number of groups are working technologies relevant for the
SYMM WG.
3GPP MMS (Multimedia
Messaging Service) and Streaming Service, specified in the 3GPP
specifications (TS 26.140,
TS 26.234
and TS
26.246 defines the MMS SMIL profile). Work on SMIL 2.1 should be
coordinated with 3GPP and 3GPP2.
The Open Mobile Alliance (OMA) is maintaining an "MMS
Conformance Document". Work on SMIL 2.1 should be coordinated with
OMA.
MPEG-7 has
developed the Multimedia Content Description Standard which may also be
used in SMIL as XML descriptions.
Society of Motion Picture and Television Engineers (SMPTE) The WG should take care of SMPTE
at large in terms of description formats of professional digital video.
e.g. Television Systems Technology (S22), Metadata and Wrapper Technology
(W25).
Audio Engineering Society (AES) is
developing a description format of professional digital audio
presentation.
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.
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.
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.
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.
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.
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.
