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Re: Asking for feedback on API design from the Web Browser Community

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Wed, 2 Dec 2009 09:16:46 +1100
Message-ID: <2c0e02830912011416x59bfcce2u190356e6044b3894@mail.gmail.com>
To: RaphaŽl Troncy <Raphael.Troncy@cwi.nl>
Cc: Joakim SŲderberg <joakim.soderberg@ericsson.com>, Doug Schepers <schepers@w3.org>, public-media-annotation@w3.org
For Ogg, all metadata is stored in VorbisComment headers and they are
track-specific, not file-specific. There can be file-wide metadata in
the skeleton track, but it's not used widely. Having it track-specific
also helps in keeping it around when segmenting the video into tracks
and recombining with others (e.g. to replace a audio track with a
different language).

ID3 headers are also associated typically with MP3 tracks, I think.

If I understand quicktime/mpeg-4 correctly, user metadata can be both
associated with the complete file (movie) and with tracks - e.g.
http://developer.apple.com/mac/library/qa/qa2001/qa1135.html .

I am mostly worried about getting a common metadata interface for
binary media files to use in HTML5 video and audio elements, so Ogg
and H.264 are my largest concern.

Cheers,
Silvia.

On Wed, Dec 2, 2009 at 8:49 AM, RaphaŽl Troncy <Raphael.Troncy@cwi.nl> wrote:
>> Most of the time the metadata is associated with tracks, so I wonder
>> how to address them.
>
> Is this really true? I agree it would be nice, but is there any metadata
> format widely used that offers such a granularity ? From my experience,
> metadata are generally global to a media file and therefore apply to all
> tracks. Complex metadata formats such as MPEG-7 allow to decompose a media
> into pieces (e.g. tracks) in order to attach metadata to these pieces, but
> people tend to say it is too complex.
>
>> For example: if I want the author of the video track and the composer
>> of the audio track?
>
> One more use case for the UC & Requirement document ?
> Cheers.
>
> †RaphaŽl
>
> --
> RaphaŽl Troncy
> EURECOM, Multimedia Communications Department
> 2229, route des CrÍtes, 06560 Sophia Antipolis, France.
> e-mail: raphael.troncy@eurecom.fr & raphael.troncy@gmail.com
> Tel: +33 (0)4 - 9300 8242
> Fax: +33 (0)4 - 9000 8200
> Web: http://www.eurecom.fr/~troncy/
>
Received on Tuesday, 1 December 2009 22:17:46 GMT

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