W3C home > Mailing lists > Public > public-html-a11y@w3.org > May 2011

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

From: John Foliot <jfoliot@stanford.edu>
Date: Wed, 11 May 2011 16:29:36 -0700 (PDT)
To: "'David Singer'" <singer@apple.com>, "'Silvia Pfeiffer'" <silviapfeiffer1@gmail.com>
Cc: "'HTML Accessibility Task Force'" <public-html-a11y@w3.org>, "'James Craig'" <jcraig@apple.com>, "'Michael Cooper'" <cooper@w3.org>
Message-ID: <006901cc1033$4a5ee010$df1ca030$@edu>
David Singer wrote:
> I think the point is that the poster and the aria-label are both about
> the video (they are peers)


>  so it might be better to say
>  <video poster="media/ClockworkOrangetrailer.jpg" controls
>         aria-label="A Clockwork Orange movie trailer">
>    <source src="media/ClockworkOrangetrailer.mp4">
>    <source src="media/ClockworkOrangetrailer.webm">
>    <source src="media/ClockworkOrangetrailer.ogv">
>  </video>

For accessibility API mapping, naming the <video> object as "A Clockwork
Orange movie trailer" would be acceptable, although I still do not believe
that it solves the broader problem statement: what is the 'textual
alternative' to this resource, for users and user-agents that do not
support/consume graphical objects? Aria-label is not text that is intended
to render on screen, it is more akin to an ID, in that it names the object
but does not display onscreen text. 

I am leery as well of making a one-time exception to aria-label when used
with <video>, as this adds additional complexity to the authoring stage
(and perhaps also to the browser/user agents).

The <video> element can take aria-label today with no change to the
specification - re-envisioning aria-label to provide alternative text
however is incorrect. 

> >
> > 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.
> >
> 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.

This is closer to my assertion: it is the label for the multi-media
'envelope' that includes both the media file(s), any <track> files, the
poster image if/when present, etc.. Using aria-label to 'stand in' as a
textual alternative remains (IMHO) inappropriate, especially if/when that
text is directly related to an image file provided via @poster.

Received on Wednesday, 11 May 2011 23:32:32 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 19:55:56 UTC