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Re: [media] text alternatives for video

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Thu, 26 May 2011 12:17:30 +1000
Message-ID: <BANLkTinQqvVnnSuLPAoH3uRRW3R7u2NmGA@mail.gmail.com>
To: HTML Accessibility Task Force <public-html-a11y@w3.org>
Hi everyone,

after today's media subgroup meeting and discussion, I posted a bug to
the HTML tracker about this, see

http://www.w3.org/Bugs/Public/show_bug.cgi?id=12794

The intention is to get wider review on this proposal.

I've not yet attacked the @transcript part of the below proposal, just
the @aria-describedby part.

Cheers,
Silvia.


On Thu, May 19, 2011 at 2:24 PM, Silvia Pfeiffer
<silviapfeiffer1@gmail.com> wrote:
> Hi all,
>
> In today's media subgroup call, the discussions on how to do text
> alternatives for video continued.
>
>
> We tightened up the requirements, which can now be summarized as follows:
>
> 1. need to support graphical and text-only browsers
>
> 2. need to support HTML5 and legacy browsers (i.e. <video> element support)
>
> 3. need to allow describing the default and custom video player layout
>
> 4. need to allow for short and long text alternative for placeholder image
>
> 5. need to allow for short and long text alternative for video
>
> 6. need to work when text alternative is on page / not on page
>
>
> After lengthy discussions, we eventually came up with the following
> markup example:
>
> <video src="file.mp4" poster="poster.png" aria-describedby="posteralt
> videosummary"
>  transcript="transcript.html" aria-label="MyPlayer video player">
>  <p id="videosummary">A Clockwork Orange Trailer (<a
> href="transcript.html">Transcript</a>)</p>
>  <p id="posteralt">Poster frame is a clockwork orange movie poster (<a
>  href="posterlongdesc.html">long description</a>)</p>
>  <p><a href="file.mp4">Download the video file</a></p>
> </video>
>
> This type of markup satisfies the above requirements as follows:
>
> 1.
> Graphical browsers display the video with poster.png as the
> placeholder image (or the first frame if no @poster attribute is
> given)
> Text-only browsers can display similar text to what is now inside the <video>
>
> 2.
> HTML5 browsers display the video with poster.png as the placeholder
> image (or the first frame if no @poster attribute is given)
> Legacy browsers display the paragraphs from inside the video element
>
> 3.
> Default layout would have a controls attribute and no text in aria-label
> Custom layout announced through the aria-label attribute
>
> 4.
> Short text alternative for the placeholder image is provided through
> aria-describedby
> Long text alternative for the placeholder image is provided through
> the link inside the paragraph for the short text alternative for the
> image
>
> 5.
> Short text alternative for the video is provided through aria-describedby
> Long text alternative for the video is provided through the link
> inside the paragraph for the short text alternative for the video, and
> also as an additional attribute on the video element so that a context
> menu can bring up a link to the transcript for sighted users
>
> 6.
> Example above is how it would work for when the text alternatives are
> not on the page
> When they are, aria-describedby can link to those paragraphs, but may
> want to add still links to long description inside the <video>
>
>
> Have we overlooked anything?
>
> Cheers,
> Silvia.
>
Received on Thursday, 26 May 2011 02:18:28 GMT

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