Comments re: proposed revised TTWG charter.

Good morning/evening,

Please find below comments on the proposed revised TTWG charter [1].

> Scope

To facilitate interoperability, industry practice has been to define
and implement constrained profiles of TTML -- see [2] for a few
examples. In particular, the TTWG has published the SDP-US Note [3],
which is focused on US captions. It would be useful for the W3C to
expand on this work, and define TTML profile(s) appropriate for
caption and subtitle delivery applications worldwide. These profile(s)
could then be referenced by other organizations, thereby reducing the
number of disjointed profiles in use.

As input, MovieLabs has provided a starting point as a member
submission at [4]. The submission specifies two profiles of the Timed
Text Markup Language (TTML): a text-only profile and an image-only
profile for use across subtitle and caption delivery applications
worldwide.

The two profiles are based on the CFF-TT profiles [5] developed by
DECE [6] -- the idea is to benefit from the technical consensus,
conformance testing and implementation experience gathered there.

The text profile is a superset of SDP-US. The image profile extends a
subset of TTML with SMPTE Timed Text (SMPTE-TT) image support. The
proposed elements and attributes from the DECE and SMPTE namespaces
are currently proposed to be added to TTML v.next per the liaison from
SMPTE [7] and as captured in TTWG Issues 224-250 [9], with the
expectation is that the image profile would ultimately be a strict
subset of TTML v.next.

So I would suggest adding to the charter:

- under Tasks: """Develop a profile of the Timed Text Markup Language
(TTML) v.next appropriate for worldwide subtitling applications,
including dialog language translation, content description, captions
for deaf and hard of hearing, etc., using [4] as basis and subset."""

- under deliverables: """"A W3C Recommendation for 'TTML Text and
Image Profiles for Internet Media Subtitles and Captions'"""

> "will [...] include all features that have at least two independent and interoperable implementations"

Is this absolutely necessary, i.e. what about if the group decides
that a feature with "two independent and interoperable
implementations" is not desirable?

> "Consider for adoption features developed by groups such as SMPTE, DECE and EBU."

I would specifically mention the SMPTE liaison [7] (see above).

> "Liaisons with W3C Groups"

I would specifically mention the Web&TV IG [8].

Looking forward to feedback and to the discussion.

Best,

-- Pierre

[1] http://www.w3.org/2013/05/timed-text-charter.html
[2] http://www.w3.org/2011/webtv/wiki/Tt/Timed_Text_Efforts#TTML-based_efforts_and_specifications
[3] http://www.w3.org/TR/ttml10-sdp-us/
[4] http://www.w3.org/Submission/2013/SUBM-ttml-ww-profiles-20130607/
[5] http://www.uvvuwiki.com/images/f/f6/CFFMediaFormat-C1.0.6.pdf
[6] http://www.uvvu.com/
[7] http://lists.w3.org/Archives/Public/public-tt/2013Jan/0006.html
[8] http://www.w3.org/2011/webtv/wiki/Main_Page
[9] http://www.w3.org/AudioVideo/TT/tracker/issues/open

Received on Thursday, 18 July 2013 15:50:43 UTC