- From: Philip Jägenstedt <philipj@opera.com>
- Date: Tue, 14 Dec 2010 17:31:24 +0100
On Wed, 24 Nov 2010 17:11:02 +0100, Eric Winkelman <E.Winkelman at cablelabs.com> wrote: > I'm investigating how TimedTracks can be used for in-band-data-tracks > within MPEG transport streams (used for cable television). > > In this format, the number and types of in-band-data-tracks can change > over time. So, for example, when the programming switches from a > football game to a movie, an alternate language track may appear that > wasn't there before. Later, when the programming changes again, that > language track may be removed. > > It's not clear to me how these changes are exposed by the proposed Media > Element events. The thinking is that you switch between different streams by setting the src="" attribute to point to another stream, in which case you'll get an emptied event along with another bunch of events. If you have a single source where audio/video/text streams appear and disappear, there's not really any way to handle it. > The "loadedmetadata" event is used to indicate that the TimedTracks are > ready, but it appears that it is only fired before playback begins. Is > this event fired again whenever a new track is discovered? Is there > another event that is intended for this situation? > > Similarly, is there an event that indicates when a track has been > removed? Or is this also handled by the "loadedmetadata" event somehow? No, the loadedmetadata event is only fired once per resource, it's not the event you're looking for. As for actual solutions, I think that having loadedmetadata fire again if the number or type of streams change would make some sense. -- Philip J?genstedt Core Developer Opera Software
Received on Tuesday, 14 December 2010 08:31:24 UTC