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Re: [media] alt technologies for paused video (and using ARIA)

From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
Date: Sun, 15 May 2011 05:36:22 +0200
To: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Cc: David Singer <singer@apple.com>, John Foliot <jfoliot@stanford.edu>, HTML Accessibility Task Force <public-html-a11y@w3.org>, James Craig <jcraig@apple.com>, Michael Cooper <cooper@w3.org>
Message-ID: <20110515053622771463.1fc62a09@xn--mlform-iua.no>
Silvia Pfeiffer, Thu, 12 May 2011 10:13:48 +1000:
> On Thu, May 12, 2011 at 8:48 AM, David Singer <singer@apple.com> wrote:
>> On May 11, 2011, at 6:50 , Silvia Pfeiffer wrote:

>>> It's a label for the video element, which in the instance of
>>> non-autoplay is simply the content of the placeholder frame. So, it's
>>> completely correct.

+1

>> I think it should be thought of as a label for the video in the 
>> element, whether or not it's playing.  So saying it's a poster is 
>> not true;  that would be the correct description of an image.
> 
> We have had the discussion in the call if it should be @alt rather
> than @aria-label. I am not opposed to it. I took @aria-label by
> recommendation from a blind screenreader developer. But it seems also
> from today's discussion that @aria-label is a confusing attribute name
> and might tend to encourage people to provide a label for the video.
> Similarly, @alt may be confusing since people may want to provide a
> summary of the video content, which is not what it should contain.

HTML5 describes @alt as 'Replacement text for use when images are not 
available' [1], and it is permitted for area, img and input. What is 
wrong by adding <video> to that list? @alt would then remain 
replacement text for the video's (poster) image.  

@alt also plays the role of 'textual substitute' when the image is not 
availabel/not displayed. And a textual substitute for video is needed, 
for instance in textual browsers. @Aria-label cannot function as 
textual substitute, unless we do a lot of reprogramming etc. And a 
@posteralt would have the same problems.

Further more, @alt would provide almost instant support in AT - since 
at least some of them respects @alt even on other elements than 
area/img/input. 

When it comes to the content of video@alt, then those should be 
described in some authoring requirement section. I think the 
requirements would need to vary depending on a) what the poster 
actually displayes, b) wheter there is telling information outside the 
video element.

[1] http://dev.w3.org/html5/spec/index.html#attributes-1


My $2
-- 
Leif H Silli
Received on Sunday, 15 May 2011 03:36:53 GMT

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