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Re: Track fragments

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Tue, 16 Feb 2010 08:23:24 +1100
Message-ID: <2c0e02831002151323q3f0c8471y53a2aa500dce130b@mail.gmail.com>
To: DENOUAL Franck <Franck.Denoual@crf.canon.fr>
Cc: "public-media-fragment@w3.org" <public-media-fragment@w3.org>
Hi Franck,

In the W3C HTML5 Accessibility Task Force, which is a subgroup of the
HTML WG, we are right now working on a API for multitrack media files,
see http://www.w3.org/WAI/PF/HTML/wiki/Media_MultitrackAPI .

Per track there will be the following attributes: name, role, type,
lang, enabled .

Right now, the only interface we have regarded for track fragment URIs
is to address them by name - which is a name given by the creator of
the resource, i.e. it could be any random string.

It is possible do devise a track addressing method that includes some
of the other attributes. For example, a combination of type, role and
lang could make sense, something like:

#track=audio(audesc, en)&video(main,en)&text(cc,en)&text(sub,fr)

I just made this up, so feel free to suggest any other markup means.

I actually have a an open issue at
http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/4 about this,
which hasn't progressed because we haven't really reached discussions
about tracks yet - our focus so far was on the time dimension. It may
be a good time now to start discussions on other dimensions.

One thing I need to add to this discussion is that track addressing
with *URI fragments* may be less about addressing and more about
activating. So, it interrelates very closely with the JavaScript API,
which is why I am waiting for that to stabilise and have some initial
implementations. This is certainly different if we use URI queries (?)
for addressing, since then we compose a new resource with just the
requested tracks.


On Tue, Feb 16, 2010 at 4:01 AM, DENOUAL Franck
<Franck.Denoual@crf.canon.fr> wrote:
> Dear fragmenters,
> Some time ago, there were discussions on defining default tracks or not...
> Also related to the track dimension, wouldn't it be interesting to have the possibility to directly address multiple tracks ?
> Suppose a multimedia presentation containing one video stream with different audio streams (english, german, french,...) and one would like to get the video stream with the english version of the audio stream.
> This is not possible with current track dimension even with the composition operator "&" since track allows the extraction of a single track.
> Best regards,
> --
>        Franck.
> P.S.: I've also seen that WG was recently extended for 1 year: do you think possibility for observers will also be extended ;-) ?
Received on Monday, 15 February 2010 21:24:17 UTC

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