W3C home > Mailing lists > Public > public-media-fragment@w3.org > September 2008

Re: Identifying vs Describing media URI fragments

From: Yves Lafon <ylafon@w3.org>
Date: Wed, 24 Sep 2008 05:43:38 -0400 (EDT)
To: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
cc: Raphaël Troncy <Raphael.Troncy@cwi.nl>, Media Fragment <public-media-fragment@w3.org>
Message-ID: <Pine.LNX.4.64.0809240532030.14879@ubzre.j3.bet>

On Wed, 24 Sep 2008, Silvia Pfeiffer wrote:

>> Giving a name with a well-defined semantics to an object is always
>> subjective. Assuming I have specified a temporal fragment of a video, and I
>> need to give a name to this fragment: for the machines, both the strings
>> "id-3454645" and "kiss-scene" are equivalent. In both case, the machine will
>> not understand what this fragment is about. Similarly, with only the
>> fragment identifier, the machine will not know that this fragment points to
>> a video encoded in the compression format x, under the resolution y, content
>> which is also available on another media server with a different
>> resolution/encoding, etc. This information is what I consider being part of
>> the semantics of the fragment. The questio again is: does this fall into the
>> scope of the WG?
> Again, I do not understand your point. The strings "id-3454645" and
> "kiss-scene" are just simple identifier of a segment and do not
> provide any semantics other than the ones that happen in the human
> mind by reading the name. However, defining a referencing scheme where
> we can use the name to identify a fragment is a different thing and
> has nothing to do with semantics. We can still say: this is a URI to
> the fragment called "id-3454645" or the fragment called "kiss-scene".
> Just like class attributes of HTML elements bear no semantics, neither
> do these.

I think Raphael's point is: should the fragment be self-descriptive enough 
a machine can figure out without external context that it is a video 
fragment. (re: [[ for the machines, both the strings "id-3454645" and
   "kiss-scene" are equivalent. In both case, the machine
   will not understand what this fragment is about ]] ).

This is especially critical when you want the machine to retrieve only the 
fragment and not the whole resource; as opposed to giving a first class 
identification to fragments (ie: giving them the resource status).

In the case of fragments, being able to merge the 0-10s fragment to the 
10s- (end) fragment in a local cache is something desirable, but it is 
difficult to achieve this if fragments are plain resources (unless you 
have extra informations available somewhere about relations between a 
potentially infinite set of resources), but I'm digressing...

Baroula que barouleras, au tiéu toujou t'entourneras.

Received on Wednesday, 24 September 2008 09:44:11 UTC

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