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

From: Michael Hausenblas <michael.hausenblas@deri.org>
Date: Wed, 28 Jan 2009 08:03:30 +0000
To: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
CC: RaphaŽl Troncy <Raphael.Troncy@cwi.nl>, Yves Lafon <ylafon@w3.org>, Media Fragment <public-media-fragment@w3.org>
Message-ID: <C5A5C1D2.1522%michael.hausenblas@deri.org>


Silvia,

> I actually also don't quite understand what your question is.

Hm. I really thought that my explanation was clear. Obviously not.

> Is this a question of process or a technical question?

Again. I think I have clearly laid out that I'm pretty aware of process
issues. Hence the answer is: it's not a process issue :)

> If it is technical:
> Your example http://www.example.com/movie.mov#xywh=20,20,40,40 is well
> described in the requirements,
>  e.g.
> http://www.w3.org/2008/WebVideo/Fragments/wiki/Use_Cases_%26_Requirements_Draf
> t#Recompositing_Media_Fragments
> http://www.w3.org/2008/WebVideo/Fragments/wiki/Use_Cases_%26_Requirements_Draf
> t#Annotating_Media_Fragments
> basically everywhere that the word "spatial fragment" is used.

Stating that the conformance - btw, which one(s) are we gonna have? Raphael?
Yves? - can be looked up in a *requirements document* reminds me on the
situation where our oldest son would ask 'Can I have a dinosaur book for
Christmas?' and I would answer 'it is written down in your whish list'.
Well, you can guess if our son was satisfied with my answer ;)

Cheers,
      Michael

-- 
Dr. Michael Hausenblas
DERI - Digital Enterprise Research Institute
National University of Ireland, Lower Dangan,
Galway, Ireland, Europe
Tel. +353 91 495730
http://sw-app.org/about.html


> From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
> Date: Wed, 28 Jan 2009 11:37:27 +1100
> To: Michael Hausenblas <michael.hausenblas@deri.org>
> Cc: RaphaŽl Troncy <Raphael.Troncy@cwi.nl>, Yves Lafon <ylafon@w3.org>, Media
> Fragment <public-media-fragment@w3.org>
> Subject: Re: ISSUE-2: What is the mime type of a media fragment? What is its
> relation with its parent resource?
> 
> Hi Michael,
> 
> I actually also don't quite understand what your question is.
> 
> Is this a question of process or a technical question?
> 
> If it is process:
> Sure we need test implementations. It is well described in our
> charter: http://www.w3.org/2008/01/media-fragments-wg.html .
> 
> If it is technical:
> Your example http://www.example.com/movie.mov#xywh=20,20,40,40 is well
> described in the requirements,
>  e.g.
> http://www.w3.org/2008/WebVideo/Fragments/wiki/Use_Cases_%26_Requirements_Draf
> t#Recompositing_Media_Fragments
> http://www.w3.org/2008/WebVideo/Fragments/wiki/Use_Cases_%26_Requirements_Draf
> t#Annotating_Media_Fragments
> basically everywhere that the word "spatial fragment" is used.
> 
> Does that help?
> 
> Regards,
> Silvia.
> 
> 
> On Wed, Jan 28, 2009 at 11:12 AM, Michael Hausenblas
> <michael.hausenblas@deri.org> wrote:
>> 
>> Raphael,
>> 
>> I know, impolite, but let's start at the end:
>> 
>>> Does that answer to your question?
>> 
>> No ;)
>> 
>> For some background reading I'd suggest [1].
>> 
>> The problem is that with the pure syntax (as of [2]) we can't fully specify
>> any conformance (UA, or whatever).
>> 
>> Example:
>> 
>> In RDFa (where I've been responsible for the TC, now with Manu Sporny
>> together), we have a processing model that would generally define how to
>> process an XHMTL+RDFa page in order to produce RDF triple. Now, we can't
>> define the output for any case (obviously too many combinations possible ;)
>> In order to define the semantics we use the TC [3]. I'll use the first TC in
>> the suite as an example:
>> 
>> ...<p>This photo was taken by <span class="author" about="photo1.jpg"
>> property="dc:creator">Mark Birbeck</span>.</p> ...
>> 
>> in our understanding should produce the triple
>> 
>> <http://www.w3.org/2006/07/SWD/RDFa/testsuite/xhtml1-testcases/photo1.jpg>
>> dc:creator "Mark Birbeck" .
>> 
>> Hence a back and forth between syntax and TC in order to define the
>> semantics. We reviewed each TC manually and the RDFa TF would then agree,
>> yes, this is the expected outcome (in sync with the syntax).
>> 
>> Then, after the TC have been completed the implementers were called (yeah,
>> sure they already did that in parallel, but theoretically sufficient if you
>> do it later).
>> 
>> In this second phase, the TC were used to determine if and to which degree
>> the RDFa syntax spec could be implemented (and, alas, also, if you have two
>> implementations that pass all TC you might be able to assume they are
>> interoperable). This is an important criteria in the Rec Track [4]:
>> 
>> "The Working Group is NOT REQUIRED to show that a technical report has two
>> independent and interoperable implementations as part of a request to the
>> Director to announce a Call for Implementations. However, the Working Group
>> SHOULD include a report of present and expected implementations as part of
>> the request."
>> 
>> Though not required I guess it is common and a good practice and fosters
>> adoption.
>> 
>> Now, back to the question: How does the above described map to our work?
>> 
>> Take <http://www.example.com/movie.mov#xywh=20,20,40,40> as an example.
>> 
>> How would the TC look? How do we specify the semantics of it?
>> 
>> Cheers,
>>      Michael
>> 
>> [1] http://www.w3.org/QA/WG/2005/01/test-faq
>> [2] http://www.w3.org/2008/WebVideo/Fragments/wiki/Syntax
>> [3] http://rdfa.digitalbazaar.com/rdfa-test-harness/
>> [4] http://www.w3.org/2005/10/Process-20051014/tr.html#cfi
>> 
>> --
>> Dr. Michael Hausenblas
>> DERI - Digital Enterprise Research Institute
>> National University of Ireland, Lower Dangan,
>> Galway, Ireland, Europe
>> Tel. +353 91 495730
>> http://sw-app.org/about.html
>> 
>> 
>>> From: RaphaŽl Troncy <Raphael.Troncy@cwi.nl>
>>> Organization: CWI
>>> Date: Wed, 28 Jan 2009 00:35:04 +0100
>>> To: Michael Hausenblas <michael.hausenblas@deri.org>
>>> Cc: Yves Lafon <ylafon@w3.org>, Media Fragment
>>> <public-media-fragment@w3.org>,
>>> Silvia Pfeiffer <silviapfeiffer1@gmail.com>
>>> Subject: Re: ISSUE-2: What is the mime type of a media fragment? What is its
>>> relation with its parent resource?
>>> 
>>> Dear Michael,
>>> 
>>>> I'll restate it and would like to ask you to explain me how we gonna handle
>>>> this - in case I understand it I offer a bounty (not sure if that has
>>>> already been assigned, so ...), that is, to take care of the Test Cases:
>>> 
>>> [Being not Yves]
>>> What is exactly your question? What would be the implementations of the
>>> spec and the test cases that come with for the CR exit?
>>> 
>>> What we have discussed so far:
>>>    - implementation of a smart UA, that can transform the fragment
>>> requested into some new http headers and do either the 2-ways or the
>>> 4-ways handshake ... ideally in collaboration with the browser vendors.
>>>    - implementation of a server, that can handle media fragment request,
>>> slide the media file on demand, and serve it to the client
>>> 
>>> Yves has his own server (jigsaw)
>>> Jack though he could do something with Ambulant, the SMIL player.
>>> Test cases will ensure that communication between UA and server will
>>> follow what is specified in the spec (re: 2-ways / 4-ways handshake in
>>> case of http implementation, etc.)
>>> 
>>> Does that answer to your question?
>>> Best regards.
>>> 
>>>    RaphaŽl
>>> 
>>> --
>>> RaphaŽl Troncy
>>> CWI (Centre for Mathematics and Computer Science),
>>> Science Park 123, 1098 XG Amsterdam, The Netherlands
>>> e-mail: raphael.troncy@cwi.nl & raphael.troncy@gmail.com
>>> Tel: +31 (0)20 - 592 4093
>>> Fax: +31 (0)20 - 592 4312
>>> Web: http://www.cwi.nl/~troncy/
>> 
Received on Wednesday, 28 January 2009 08:04:17 GMT

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