[whatwg] Video, Closed Captions, and Audio Description Tracks

[Anne van Kesteren]

On Tue, 09 Oct 2007 18:03:41 +0200, Maik Merten <maikmerten at gmx.net> wrote:
>> http://www.w3.org/TR/2006/CR-ttaf1-dfxp-20061116/
>
> Actually I wonder if it wouldn't make sense to have an attribute for
> media elements specifying a URI for a file containing Timed Text. These
> externally stored (not embedded in a media file) captions would be
> codec-agnostic and could be used to reuse the very same set of captions
> for e.g. differently encoded media (Ogg, MPEG,
> Generic-Codec-Of-The-Season, ...).

This would be problematic when downloading the video for offline use or  
further distribution. This is also different from how this currently works  
for DVDs, iPod, and the like as far as I can tell. It also makes authoring  
more complicated in the cases where someone hands a video to you as you'd  
have to separate the closed caption stream from it first and point to it  
as a separate resource.


> As a side note I like the idea of captions which are more than just the
> usual stream text. Imagine a newsreel with timed "Would you like to know
> more?" links. Given that HTML5 is usually viewed in browsers that
> implement at least a non-empty subset of HTML I imagine it should be
> possible for the browser to layer something div-equivalent over the
> media elements supporting captioning and pipe the HTML captions into it
> (with caution, imagine a caption itself recursively embedding a video).

I think the cue points feature is designed to do that.


-- 
Anne van Kesteren
<http://annevankesteren.nl/>
<http://www.opera.com/>