Re: Proposed extension to HTML5.1 for rollup captions

On Wed, Feb 20, 2013 at 1:46 PM, Travis Leithead <
travis.leithead@microsoft.com> wrote:

> > From: Silvia Pfeiffer [mailto:silviapfeiffer1@gmail.com]
> >
> > I'm looking for feedback on this feature here. If there are no objections
> > and sufficient support for these features, I suggest adding them to the
> > HTML5.1 specification.
>
> I'm very cautious about immediately merging this feature back into
> HTML5.1. I believe the best course of action is to keep this feature
> separate from the HTML5.1 spec (as a stand-alone document) as it allows
> easier review, as well as time to get consensus and develop the proposal
> based on feedback.
>
> Given that there is some time elapsed between now and when you can get
> sufficient support, then I don't object to merging it in. I would prefer to
> have at least a month or two to have time to gather all the right people
> together, perform the review, summarize and submit (and have time for you
> to incorporate any feedback).
>
> Finally, just a quick "thank you" for putting this together. I really like
> that extension specs are starting to be developed and I want to encourage
> folks to continue to submit these and get them started as reviewable
> documents.
>

A few questions of clarification:

   - does this rollup caption extension depend on
   https://dvcs.w3.org/hg/text-tracks/raw-file/default/608toVTT/region.html?
if the answer is yes, then these TextTrackRegion interface extensions
   need to be renamed to WebVTTTextTrackRegion or otherwise made more generic
   to accommodate use of TTML instead of WebVTT
   - does the mechanisms defined as extensions to the current HTML5
   TextTrack and related interface types take into account use of TTML instead
   of WebVTT? if the answer is no, then it should be reviewed and modified as
   needed to permit use of TTML as well, or at least support future
   integration with TTML

Overall, we need to keep in mind that TTML will be used by commercial video
content providers for captioning HTML5 media elements, and any features
defined to support TextTracks needs to separate generic functionality|usage
from text track format specific functionality|usage.