[whatwg] Thoughts on video accessibility
singer at apple.com
Tue Dec 9 20:56:08 PST 2008
At 21:33 +1300 9/12/08, Robert O'Callahan wrote:
>For what it's worth, loading an intermediate document of some new
>type which references other streams to be loaded adds a lot of
>complexity to the browser implementation. It creates new states that
>the decoder can be in, and introduces new failure modes. It creates
>new timing issues and possibly new security issues.
I'm not sure I agree; but if you believe that, we should address it
no matter which way this discussion goes. It should absolutely be
possible to reference a SMIL file, or an MP4 or MOV file with
external data (to give only two examples) from a <video> or <audio>
element, and have the DOM, events, states, and APis work correctly.
Also, I should say that we quite deliberately left off associating
and synchronizing media from our initial proposal for the media
elements, for two reasons:
a) we believe that SMIL files should be embeddable;
b) it's an easy line to draw; you want media integration, use a
media integration language such as SMIL. If you start adding some
integration, it's very hard to know where to stop.
As for user or user-agent supplied subtitles etc., that can (of
course) be a UA feature or option. If a unique content ID would help
find such subtitle files, then I am hoping that the media annotations
group would come up with a workable scheme (something the music
industry is still, ahem, struggling with).
Multimedia Standards, Apple Inc.
More information about the whatwg