- From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
- Date: Thu, 18 Feb 2010 10:53:12 +1100
- To: Eric Carlson <eric.carlson@apple.com>
- Cc: Philip Jägenstedt <philipj@opera.com>, Geoff Freed <geoff_freed@wgbh.org>, HTML Accessibility Task Force <public-html-a11y@w3.org>
I have tried to summarise everything we have agreed on in http://www.w3.org/WAI/PF/HTML/wiki/Media_TextAssociations . Could you please make your changes there directly and just report back here on them in case there is something controversial? I think we're in the stage where we all agree on the principle approach and are filling in the meat, which shouldn't be too controversial any more. * I agree with giving <track> and end tag (not sure how to put that into the spec). * The <track> element already has a @media attribute - we just need to add some examples to the wiki page. * Please fill in the necessary state changes to the media element as you implement things, since I think that's when we will realise the implications. * I think if no track in a trackgroup is enabled, they should all stay disabled unless some browser preferences for the user say otherwise. * agree with everything else Cheers, Silvia. On Thu, Feb 18, 2010 at 3:31 AM, Eric Carlson <eric.carlson@apple.com> wrote: > > On Feb 17, 2010, at 12:00 AM, Philip Jägenstedt wrote: > > On Wed, 17 Feb 2010 15:10:06 +0800, Silvia Pfeiffer > <silviapfeiffer1@gmail.com> wrote: > > Maybe we have converged? > > Yes, and for the record this is what I think we agree on: > > <track> is used to reference an external text track. > > Although we are only talking about external text tracks at the moment, I > think we will be talking about other media types soon enough (eg. audio > description) so I would say > <track> is used to reference an external track. > > <trackgroup> is used to group several tracks which are mutually exclusive. > Often they will have the same role="", but this isn't necessarily so. > > Your example with active changed to enabled: > > <video src="video.ogv"> > <track src="cc.en.srt" srclang="en" role="CC" enabled> > <track src="tad.en.srt" srclang="en" role="TAD"> > <trackgroup role="SUB"> > <track src="subs.de.srt" srclang="de"> > <track src="subs.sv.srt" srclang="sv"> > <track src="subs.jp.srt" srclang="jp"> > </trackgroup> > </video> > > <track> is a void element (no end tag), if there any reason to think that it > would ever need child elements then now is the time to give it an end tag. > > I think we will need an end tag to allow <track> to have <source> elements > for non-text media formats, for example audio description tracks, as long as > we don't have a mandated format. > One thing we are missing here is the "media" attribute. All of the > examples we have used so far have selected alternates based on language but > we also need to be able to consider a user's accessibility needs when > choosing between track alternates. I believe that a content author should be > able to describe a track with exactly the same media query syntax we are > developing to describe movies. > Another major topic we haven't talked about is how external tracks affect > the movie's readyState and networkState. For example, if a movie's readState > is HAVE_FUTURE_DATA and the user or a script enables a track for the first > time, the readyState should drop back to HAVE_METADATA. I don't think this > will be difficult, but we need to spell out all of the state changes > thoroughly. > Some questions and thoughts, in no particular order: > + I assume that if I use our track API to examine the track tracks in a > trackgroup, the one chosen from among a group of alternates is enabled, and > the others are not? > + I also assume that if I set the enabled property on one track in a group > all of the others are automatically disabled? > + Do we enable the first track in a group if none match? > + I think that a media query that evaluates to "false" means it *must* not > be enabled because it is not appropriate for the user's environment, so > should setting enabled to true on such a track just fail? > > On Feb 16, 2010, at 9:49 PM, Silvia Pfeiffer wrote: > > Agreed. I think that confirms the above proposal? > > I'm curious what Eric and Geoff think about this now? > > We are getting there ;-) > > eric > >
Received on Wednesday, 17 February 2010 23:54:05 UTC