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RE: ISSUE-309 (Image profile fails WCAG 1.2): Image profile needs to permit text equivalent [TTML IMSC 1.0]

From: John Birch <John.Birch@screensystems.tv>
Date: Thu, 22 May 2014 08:41:01 +0000
To: Michael Dolan <mdolan@newtbt.com>, 'Timed Text Working Group' <public-tt@w3.org>
Message-ID: <0981DC6F684DE44FBE8E2602C456E8AB014F72EBC5@SS-IP-EXMB-01.screensystems.tv>
Hi Mike,

It wasn’t overlooked in W3C. TTML is a text based format and so it is inherently accessible to presentation by non-visual means (like braille displays and text to speech).

Thank you for your clarification that it was considered, my use of the term ‘overloooked’ is thus clearly invalid and I apologise for making that assumption.
However I have to say that the fact that it was “rejected as it created more problems than it solved” is very surprising. I would be extremely interested to know the reasoning behind that decision.

I am surprised because CFF-TT content must (almost irrefutably) be derived from a text precursor, (I have yet to encounter subtitles or captions scanned from hand drawn script ;-) and consequently the provision of a text description against an image in CFF-TT would clearly be a trivial exercise.

In my opinion, the provision of an alternative track does not meet WCAG2 guideline 1.1, and it is my experience that providing the opportunity to omit accessibility information almost inevitably means that it is omitted. IMO that *is* a **pity** when (also IMO) it can so easily be included.

Best regards,
John

John Birch | Strategic Partnerships Manager | Screen
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From: Michael Dolan [mailto:mdolan@newtbt.com]
Sent: 21 May 2014 20:02
To: 'Timed Text Working Group'
Subject: RE: ISSUE-309 (Image profile fails WCAG 1.2): Image profile needs to permit text equivalent [TTML IMSC 1.0]

“Overlooked” and a “pity” in W3C perhaps, but not in CFF where it was studied and rejected as it created more problems than it solved.  Alternative full tracks/documents are a much cleaner solution in full media files (e.g. MP4).

Maybe W3C has different requirements for stand-alone TTML documents?

No objection to enabling it, but we could do with less judgment about other industry work.

                Mike

From: John Birch [mailto:John.Birch@screensystems.tv]
Sent: Wednesday, May 21, 2014 2:02 AM
To: Timed Text Working Group
Cc: Glenn Adams
Subject: RE: ISSUE-309 (Image profile fails WCAG 1.2): Image profile needs to permit text equivalent [TTML IMSC 1.0]

This is actually a very old ‘requirement’… (it’s a great pity it is consistently over-looked ☹

http://www.w3.org/2005/03/21/DFXPLastCallResponses.html - specifically Al Gilman’s comments
http://lists.w3.org/Archives/Public/public-tt/2003May/0011.html

http://lists.w3.org/Archives/Public/public-tt/2003May/0015.html


best regards,
John

John Birch | Strategic Partnerships Manager | Screen
Main Line : +44 1473 831700 | Ext : 2208 | Direct Dial : +44 1473 834532
Mobile : +44 7919 558380 | Fax : +44 1473 830078
John.Birch@screensystems.tv<mailto:John.Birch@screensystems.tv> | www.screensystems.tv<http://www.screensystems.tv> | https://twitter.com/screensystems


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From: Glenn Adams [mailto:glenn@skynav.com]
Sent: 21 May 2014 09:41
To: Timed Text Working Group
Subject: Re: ISSUE-309 (Image profile fails WCAG 1.2): Image profile needs to permit text equivalent [TTML IMSC 1.0]

I had previously reported this same comment on the CFF-TT image profile.

On Wed, May 21, 2014 at 5:32 PM, Timed Text Working Group Issue Tracker <sysbot+tracker@w3.org<mailto:sysbot+tracker@w3.org>> wrote:
ISSUE-309 (Image profile fails WCAG 1.2): Image profile needs to permit text equivalent [TTML IMSC 1.0]

http://www.w3.org/AudioVideo/TT/tracker/issues/309


Raised by: Nigel Megitt
On product: TTML IMSC 1.0

IMSC1 Image profile [1] defined in §6 does not permit a text equivalent. If this profile is used to provide captions as an alternative to audio then it will fail the WCAG2 guideline 1.2 [2]. From a practical perspective this would mean that users who can neither see nor hear well can not use tools to translate the content into e.g. Braille.

[1] http://www.w3.org/TR/ttml-imsc1/#image-profile-constraints

[2] http://www.w3.org/TR/2008/REC-WCAG20-20081211/#media-equiv


Some potential ways to solve this:
1. Permit text to be included within the image profile that describes the images.
2. Require or recommend that when image profile captions are provided there should be a text profile caption track available simultaneously.




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Received on Thursday, 22 May 2014 08:41:33 UTC

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