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RE: [media] Moving forward with captions / subtitles

From: Geoff Freed <geoff_freed@wgbh.org>
Date: Wed, 17 Feb 2010 08:04:37 -0500
To: Silvia Pfeiffer <silviapfeiffer1@gmail.com>, Philip Jägenstedt <philipj@opera.com>
CC: Eric Carlson <eric.carlson@apple.com>, HTML Accessibility Task Force <public-html-a11y@w3.org>
Message-ID: <B3526F4AC3C3C64388BF661A8B2112A75EE20ABB96@EXCHCCR.wgbh.org>

________________________________________
From: Silvia Pfeiffer [silviapfeiffer1@gmail.com]
Sent: Wednesday, February 17, 2010 6:56 AM
To: Philip Jägenstedt
Cc: Geoff Freed; Eric Carlson; HTML Accessibility Task Force
Subject: Re: [media] Moving forward with captions / subtitles

On Wed, Feb 17, 2010 at 7:00 PM, Philip Jägenstedt <philipj@opera.com> wrote:
> On Wed, 17 Feb 2010 15:10:06 +0800, Silvia Pfeiffer
> <silviapfeiffer1@gmail.com> wrote:
>
>> Maybe we have converged?
>
> Yes, and for the record this is what I think we agree on:
>
> <track> is used to reference an external text track.

GF:  Agreed.  

>
> <trackgroup> is used to group several tracks which are mutually exclusive.
> Often they will have the same role="", but this isn't necessarily so.

GF:  So role is *not* a requirement for <trackgroup>, correct?

>
> Your example with active changed to enabled:
>
> <video src="video.ogv">
>  <track src="cc.en.srt" srclang="en" role="CC" enabled>
>  <track src="tad.en.srt" srclang="en" role="TAD">
>  <trackgroup role="SUB">
>    <track src="subs.de.srt" srclang="de">
>    <track src="subs.sv.srt" srclang="sv">
>    <track src="subs.jp.srt" srclang="jp">
>  </trackgroup>
> </video>
>
> <track> is a void element (no end tag), if there any reason to think that it
> would ever need child elements then now is the time to give it an end tag.

GF:  I can't think of a reason today, but there may be reasons in the future.  Is it a big deal to require an end tag?  If not, I think we should require one now.

Re enabling/disabling:  in the example above, the CC track is enabled by default while the others are enabled at the user's discretion.  Would it not be more logical, and more consistent with other attribute structures, to use markup to make this explicit?  That would require the use of enable="on" or enable="off" on each track.  Hmmm.  This is akin to SMIL's systemCaptions="on/off".  And that brings up the SMIL argument again.

>

I've tentatively updated the wiki with this specification (there may
be bugs, so please read carefully and fix):
http://www.w3.org/WAI/PF/HTML/wiki/Media_TextAssociations . We can
always roll back if there is disagreement.

Cheers,
Silvia.
Received on Wednesday, 17 February 2010 13:05:58 GMT

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