RE: MPEG-2 TS Closed Caption mapping

The problem I identified related to passing a caption service of type line 21 as an audio or video track which then wouldn't provide an attribute of mode and hence no way for the application to enable them. The latest version of the spec fixes that in that it only creates text tracks for caption services.

Regards

Graham

On May 12, 2014 2:14 PM, "Ladd, Pat" <Pat_Ladd2@cable.comcast.com> wrote:
Graham;

    I took a different meaning from your question.  In http://rawgit.com/silviapfeiffer/HTMLSourcingInbandTracks/master/index.html section 3, the table in step 3 indicates that when a Caption Service Descriptor is signaled in a PMT a TextTrack is created with kind "captions" and in the case of captions digitized in the video stream, i.e. CEA708, the id is the PID of the video elementary stream carrying the captions.  What I gather from that is setting the captions TextTrack mode to showing will cause the captions in the video stream to be rendered.

Pat...

-----Original Message-----
From: Silvia Pfeiffer [mailto:silviapfeiffer1@gmail.com]
Sent: Sunday, May 11, 2014 12:52 PM
To: Clift, Graham; Bob Lund
Cc: public-inbandtracks@w3.org
Subject: Re: MPEG-2 TS Closed Caption mapping

Hi Graham,

audio and video tracks can be activated the same way that text tracks are, except there is no browser-provided default UI, so the JS developer has to do that.

AudioTrack has 'enabled'
http://www.w3.org/html/wg/drafts/html/master/embedded-content.html#dom-audiotrack-enabled
and
VideoTrack has 'selected'
http://www.w3.org/html/wg/drafts/html/master/embedded-content.html#dom-videotrack-selected
.

HTH.

Also note that Bob has made a small change to the new spec and updated the caption selection part:
http://rawgit.com/silviapfeiffer/HTMLSourcingInbandTracks/master/index.html

Cheers,
Silvia.


On Sat, May 10, 2014 at 3:27 AM, Clift, Graham <Graham.Clift@am.sony.com> wrote:
> The ‘Sourcing In-band Media Resource Tracks from Media Containers into HTML’
> spec seems to imply that CC track description will either be presented
> to the application as a TextTrack when the captions are not line 21 or
> as Audio/Video track when they are line 21.
>
>
>
> So the question I had is, how does the application set line 21
> captions to showing when contained as an audio or video track?
>
>
>
> Regards
>
>
>
> Graham