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RE: Is longdesc a good solution? (was: Acessibility of <audio> and <video>)

From: John Foliot <foliot@wats.ca>
Date: Wed, 10 Sep 2008 13:04:55 -0700
To: "'Henri Sivonen'" <hsivonen@iki.fi>, "'Matt Morgan-May'" <mattmay@adobe.com>
Cc: "'Leif Halvard Silli'" <lhs@malform.no>, "'HTML WG'" <public-html@w3.org>, "'W3C WAI-XTECH'" <wai-xtech@w3.org>
Message-ID: <000501c91380$83e3b610$0a00000a@stanford.edu>

Henri Sivonen wrote:
> On Sep 9, 2008, at 23:16, Matt Morgan-May wrote:
> 
>> HTML5 should have support for secondary audio tracks in any event.
>> Multilingual programming is another viable use case.
> 
> However, modeling the selection mechanism for multilingual programming
> is much more difficult than modeling the selection mechanism for audio
> description, so the problems of conflating captioning and subtitling
> apply here as well (with the twist that additional audio tracks take
> more bandwidth, so it is less likely for additional audio tracks to
> get muxed into the same stream).

I agree with Henri here - bandwidth is an issue.  However Matt's point of
assuring that the different support pieces can be referenced from within the
<video> object must exist, and then we can supply actual url/content via
user-choice mechanisms.  I had previously pointed out the following which
illustrates well what I believe we need to have supported natively (or at
least very close to...):

<snip>
TEST CASES / EXAMPLES:
Some good examples "in the wild" of this type of functionality can be found
at:
	http://ecorner.stanford.edu/authorMaterialInfo.html?mid=1716
	http://ecorner.stanford.edu/authorMaterialInfo.html?mid=1171
(both videos feature multi-language text options (subtitles) that can be
toggled on or off  - a perfect case where this type of functionality
enhances all user's experience and extends the usefulness of the media
asset.  As well, the time-stamped transcripts, being external files, can
also be further processed via XSLT <sic> or similar [the "Transcript" link]
and provided as on-screen html text - a real SEO consideration as well - a
virtual "cut-curb" of the highest value.  This has to be seen as a win-win
IMHO)
	http://www.jeroenwijering.com/?item=Making_video_accessible 
(the Coronation street example features both closed captioning *and*
descriptive audio - almost completely unheard of on the web today, but not
due to a lack of need, but rather of complexity in implementation to date)

While these examples have some problems (my friends at Apple have issues
with a flash based player and Voiceover, and of course these do not work in
the iPhone), but the *idea* I believe is worth exploring as a starting point
for the type of functionality that HTML 5 should afford natively.
</snip>

JF
Received on Wednesday, 10 September 2008 20:06:00 UTC

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