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Re: ISSUE-2 (Raphael): What is the mime type of a media fragment? What is its relation with its parent resource?

From: Conrad Parker <conrad@metadecks.org>
Date: Thu, 5 Feb 2009 10:38:39 +1100
Message-ID: <dba6c0830902041538g2ef03717n83e49dc42f78e426@mail.gmail.com>
To: Media Fragments Working Group WG <public-media-fragment@w3.org>

2009/1/22 Media Fragments Working Group Issue Tracker <sysbot+tracker@w3.org>:
>
> ISSUE-2 (Raphael): What is the mime type of a media fragment? What is its relation with its parent resource?
>
> http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/2
>
> Raised by: RaphaŽl Troncy
> On product:
>
> Related to a discussion started by Guillaume [1].
>
> A media fragment URI can be used for addressing, for example, a particular audio track of a mkv movie, or a particular key-frame of a video. What is the resulting mime type of the secondary resource specified by the fragment (audio, thumbnail, text)? Should we specify it in the recommendation?
> What RFC3986 does say about the mime type of a fragment [2]?
>
> Side issue: in case we create a new resource (i.e. using the query '?' parameter instead of the fragment '#' parameter), how do we make explicit the relationship with the parent resource it was extracted from?
> Do we use Link: rel="part_of" <video_uri> as suggested by Yves [3]?

Working backwards:

I think using the HTTP response header:

Link: rel="part_of" <video_url>

to signify that a retrieved resource is derived from something else is
an excellent idea, and is useful
regardless of fragment syntax. This loosely couples the method of the
derivation from the resources, which
makes them easier to use in applications -- eg. an application that is
showing thumbnails can treat them
as if they are normal images.

Secondly, I think the mime type of any retrieved resource should be
the mime type of its content, so that if
a PNG image is derived from a video, the mime-type of the derivative
should be image/png.

I don't think using '#' syntax for such a use-case is beneficial: it
would only complicate applications and
user-agents.

Conrad.
Received on Wednesday, 4 February 2009 23:39:31 GMT

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