- From: Bob Lund <B.Lund@CableLabs.com>
- Date: Sun, 2 Nov 2014 15:57:27 +0000
- To: Silvia Pfeiffer <silviapfeiffer1@gmail.com>, Cyril Concolato <cyril.concolato@telecom-paristech.fr>
- CC: "Abello, Jean-Pierre" <Jeanpierre.Abello@nielsen.com>, "public-inbandtracks@w3.org" <public-inbandtracks@w3.org>, Eric Carlson <eric.carlson@apple.com>
On 11/2/14, 3:45 AM, "Silvia Pfeiffer" <silviapfeiffer1@gmail.com> wrote: >On Wed, Oct 29, 2014 at 8:48 AM, Cyril Concolato ><cyril.concolato@telecom-paristech.fr> wrote: >> Hi Jean-Pierre, >> >> Le 28/10/2014 05:02, Abello, Jean-Pierre a écrit : >>> >>> Hello Cyril, >>> >>> It was great meeting you today. >> >> Thanks. I'm glad to meet people who have interest in the work of this >>CG. >>> >>> >>> It would be awesome if the spec could also define mappings for HLS. >> >> Yes, I do think HLS is another format that we should target. It has some >> commonalities with existing formats that we target: DASH for the use of >> manifests and adaptative streaming aspects; and MPEG-2 TS as a segment >> format. The basics of exposing tracks from TS should be reusable. It >>might >> need some tweaking compared to what we started specifying, for instance >>to >> expose ID3 Tag PES streams. In an informal discussion with Eric (in >>copy), I >> discovered that WebKit already exposes them using some API, see: >> >>http://trac.webkit.org/browser/trunk/LayoutTests/http/tests/media/track-i >>n-band-hls-metadata.html > >For the record: I do have some reservations about adding DASH and HLS >support, since browsers do not typically support these formats >natively. Actually, HLS is supported in Safari, so it has some excuse, >but DASH is only supported via Media Source Extensions. I have been >worried about that a bit. There has been text added to the spec for DASH using MSE. MSE behavior is that the UA sources tracks based on information in Initialization Segments. The application may specify default track attributes for those tracks, which the UA will use if those same attributes are not sourced from Initialization Segment data. It seems useful to me for the sourcing spec to describe this. On a related note, I plan to submit an MSE bug so that it references the sourcing spec for sourcing tracks as described above. > >I think these facts probably need to be explained better in the >document. This is particularly important, since different target >audiences are addressed with the different formats: DASH and HLS >address Web Developers (+Safari), MPEG-4, WebM and Ogg address Browser >developers, and MPEG-2 addresses Web-enabled set-top box vendors >(these are still UA devs). So, DASH and HLS are bascially in a league >of their own and should probably be moved to an appendix or so. > >Silvia. > > > >>> >>> Do you have a recommendation on how to best add this to the draft? >> >> One way would be to file a bug on the current draft, with or without a >>Git >> Pull Request proposing additional/modified spec text. >> >> Best regards, >> >> Cyril >> >> -- >> Cyril Concolato >> Multimedia Group / Telecom ParisTech >> http://concolato.wp.mines-telecom.fr/ >> @cconcolato >> >> >
Received on Sunday, 2 November 2014 15:57:57 UTC