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Requirements for external text alternatives for audio/video

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Mon, 15 Mar 2010 11:08:25 +1100
Message-ID: <2c0e02831003141708y58af3acjbc86ef1f9ce30758@mail.gmail.com>
To: HTML Accessibility Task Force <public-html-a11y@w3.org>
Hi all,

Looking at the recent survey on caption formats and its results, see
http://www.w3.org/2002/09/wbs/44061/media-text-format/results, it
seems that what is currently written in the change proposal at
http://www.w3.org/WAI/PF/HTML/wiki/Media_TextAssociations#File_Formats
got confirmed:

"A brief discussion at the TPAC in November 2009 seemed to indicate
that the W3C Timed Text Format DFXP should be the first choice. As an
alternate, simple format the SubRip srt format in its simplest form
should also be supported by browsers. Since srt can be regarded as a
simple subpart of DFXP, creating support for srt will be simple."

We have 15 voices for SRT and 14 for DFXP.

However, looking at the detailed replies, I can see that we basically
have two camps: one that says "let's just start simple" and the other
that says "we need something that is extensible, incorporates styling
and markup".

What it tells me is that we never really looked at what our
requirements for synchronised text alternatives, and in particular for
caption formats here.

I'd like us to collect these requirements so we can make a better
recommendation as a group. We should look at these requirements from
several view points, some of which may be:
* a legal POV (what do a11y laws require us to do),
* a WCAG requirements POV,
* a a11y user's usability POV,
* an international user's POV,
an anything you can think of that I forgot.

So, let me pose the key question: why do we need more than unformatted
text, a start time and an end time to provide subtitles/captions for
users?

Or let me be a bit more of a devil's advocate:
What functionality is required on top of SRT and who needs it? Seeing
as, e.g. YouTube doesn't only start time, end time and unformatted
text and gets very far with it, why would we need to support more than
that?

Please help us keep this a debate on facts and on real requirements
and not turn it into a religious debate.

Best Regards,
Silvia.
Received on Monday, 15 March 2010 00:09:24 GMT

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