- From: Bob Lund <B.Lund@CableLabs.com>
- Date: Thu, 7 Nov 2013 16:33:08 +0000
- To: Brendan Long <B.Long@cablelabs.com>
- CC: "public-inbandtracks@w3.org" <public-inbandtracks@w3.org>
On 11/7/13 9:09 AM, "Brendan Long" <B.Long@cablelabs.com> wrote: >> MPEG-2 TS Descriptive video service in North America is a secondary >>audio >> track with the main dialogue and video descriptions premixed. There is >>no >> @kind value to denote this, so the only way the Web app can identify >>such >> a track is by examining the metadata descriptor. > >Isn't this what "main-desc" is for? > >http://www.w3.org/TR/html5/embedded-content-0.html#dom-audiotrack-kind Yes, and thanks for pointing this out - this appears to be a new kind since I last looked. But, I think this highlights the issue. In the past, Descriptive Video Service had been standardized in MPEG-2 TS AC3 audio but there was not a @kind value. Now, there is, but AAC DVS is in the process of being standardized and there is not a @kind value. It is possible to take the tact that @kind table will be updated as relevant audio and video standards evolve. Or, track meta-data can be made available to the Web app so it can make the determination. The two approaches are not incompatible. Relying only on @kind means there may be a lag between availability of new audio and video services and when Web apps might make use of them.
Received on Thursday, 7 November 2013 16:33:32 UTC