[whatwg] Alt attribute for <video> and <audio>

[Silvia Pfeiffer]

On Fri, Aug 14, 2009 at 9:13 PM, Ian Hickson<ian at hixie.ch> wrote:
> On Mon, 10 Aug 2009, Remco wrote:
>>
>> Shouldn't <video>s and <audio>s (and maybe <object>s too?) also have an
>> alt attribute? A quick Google search tells me this has not been
>> discussed before.
>
> For users who can use audio but not video, authors should either provide
> audio descriptions in the video file as alternative tracks, or
> supplemental material provided in links available to everyone near the
> video.
>
> For users who can use video but not audio, authors should provide
> subtitles, captions, or transcripts either in the video or audio file as
> supplemental tracks, or in supplemental materials available to everyone in
> links near the video.
>
> For users who can use neither video nor audio, supplemental materials are
> likely the best thing for an author to provide, again, in links visible to
> all.
>
> For users of legacy UAs that don't support these features, feature-rich
> alternatives such as plugins can be provided as fallback content for
> <video> and <audio>.
>
> Captions and subtitles can be included either directly in the media file,
> or scripts can manually support external resources using the cue range
> API. Going forward, we will probably also support dedicated formats that
> UAs can merge with the video to handle showing external subtitles
> natively.
>
> I don't see a need for an alt="" attribute here. What problem would it
> solve that is not solved by the above solutions?

There is only one thing I can think about that an "alt" attribute
could provide that nothing else does: as a blind user tabs onto a
video element, the "alt" attribute's content could be read out and
briefly describe what is visible in the poster image - or
alternatively give a brief summary of the video. This is useful for
all those cases where no surrounding text is given for whatever
reason. Where a surrounding text is given, such as the video title and
description, such text is likely not necessary.

Cheers,
Silvia.