Re: Support for advanced caption features (inc rollup)

On Tue, 4 Dec 2012, Anna Cavender wrote:
> >
> > The requirements are similar (though not even remotely identical, for 
> > example there's no way to drag and drop cues on a TV), but the 
> > constraints are vastly different (for example, live TV historically 
> > couldn't have a two-second delay loop and users care more about 
> > syncing captions to the picture than readable captions, but on the 
> > Internet a two-second delay is a non-issue even for live streams and 
> > so we can get readable captions and still get the sync right).
> 
> A two-second delay will certainly be an issue for real-time interactive 
> communication.  Real-time captioning in these scenarios should be 
> displayed as soon as it is available and any delay will negatively 
> affect access to the conversation.  The idea of rendering regions seems 
> crucial here.

Given that neither <video> nor WebVTT support real-time captioning, this 
is kind of moot in a discussion of WebVTT and <video>.

If we wanted to support real-time captions of low-latency video we'd have 
to do far more than just put roll-up captions in WebVTT.

(Note that instant messaging isn't "roll-up", by the way. It's line-at-a- 
time, and as a near non-stop user of this medium, I'm pretty confident in 
saying that that is fine.)

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

Received on Tuesday, 4 December 2012 22:42:38 UTC