On Fri, Mar 18, 2011 at 8:22 PM, Silvia Pfeiffer <silviapfeiff...@gmail.com> wrote: > On Sat, Mar 19, 2011 at 6:29 AM, Eric Winkelman > <e.winkel...@cablelabs.com> wrote: >> Use Case: >> >> Many video streams contain in-band metadata for application signaling, and >> other uses. By using this metadata, a web page can synchronize an >> application with the delivered video, or provide other synchronized services. >> >> An example of this type of metadata is EISS ( >> http://www.cablelabs.com/specifications/OC-SP-ETV-AM1.0-I06-110128.pdf ) >> which is used to control applications that are synchronized with a >> television broadcast. >> >> In general, a media stream can be expected to carry several types of >> metadata and the types of metadata may vary in time. >> >> Problem: >> >> For in-band metadata tracks, there is neither a standard way to represent >> the type of metadata in the HTMLTrackElement interface nor is there a >> standard way to represent multiple different types of metadata tracks. >> >> Proposal: >> >> For TimedTextTracks with kind=metadata the @label attribute should contain a >> MIME type for the metadata and that a track only contain Cues created from >> metadata of that MIME type. >> >> This implies that streams with multiple types of metadata require the >> creation of multiple metadata track objects, one for each MIME type. > > > I don't understand. Are you saying that right now all tracks that are > of kind=metadata are made available through a single TextTrack? Cause > I don't think that's the case. > > Or are you worried about text track files that contain more than one > type of metadata? If the latter, then how is the browser to know how > to separate out the individual cues from a single track into > multipled? > > Can you clarify?
I'm also somewhat confused. The OP mentions in-band metadata, but then proposes adding something to out-of-band <track kind=metadata> elements. I'm not familiar enough with in-band metadata tracks to know if it would be useful to expose additional information about them, but for out-of-band tracks I suspect that any information you may need is application-specific, and thus can be served with a data-* attribute. ~TJ