Re: Wiki update

there might be devices/specs (e.g. HbbTV) where dash is supported natively
and NOT via MSE, hence a "standard" mapping may still be useful, to avoid
people come up with their own.

On Sun, Nov 2, 2014 at 9:30 PM, Silvia Pfeiffer <silviapfeiffer1@gmail.com>
wrote:

>
> On 3 Nov 2014 03:42, "Cyril Concolato" <
> cyril.concolato@telecom-paristech.fr> wrote:
> >
> > Hi Bob, Silvia,
> >
> > Le 02/11/2014 16:57, Bob Lund a écrit :
> >>
> >>
> >> 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:
> >>>>
> >>>> 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.
> >
> > [CC] I've heard that Webkit/GTK has some native support for DASH, but I
> couldn't verify it. I would expect that in the future some browsers have
> native support for DASH or HLS. But I agree with you that support for
> DASH/HLS is different from direct support for TS/MP4/OGG...
> >
> >>> 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.
> >
> > What about adding a diagram like this one to the introduction:
> > http://concolato.wp.mines-telecom.fr/files/2014/11/inband-sourcing.png
> > and maybe indicating that some implementations may use one path or the
> other.
> >
>
> Adding a diagram like this is useful, but I don't understand the one you
> made. In particular, all the media format parsing is happening in the UAs
> and not in an app.
>
> I'll have a go at it later.
>
> Cheers,
> Silvia.
>