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Re: Media Fragment URI Syntax: 3 polls now open

From: RaphaŽl Troncy <Raphael.Troncy@cwi.nl>
Date: Thu, 22 Jan 2009 18:35:44 +0100
Message-ID: <4978AE70.4010300@cwi.nl>
To: Dave Singer <singer@apple.com>
CC: Media Fragment <public-media-fragment@w3.org>

Dear Dave,

> I was looking at these, but a first glance didn't get me to the point 
> where I understood the questions very well (the IRC logs are not 
> completely revealing).  What's the best statement of the 
> question/problem for each one?

Hum, I'm sorry that the phrasing of the questions and the context I 
tried to put around is not clear enough for the ones who were not in 
Ghent :-( Let me give it another try ...

During our 2nd face to face meeting, we have brainstormed on what would 
be the syntax of the media fragment URI. The wiki page summarizing the 
current syntax is [1]. There are still some issues for which we haven't 
make a formal decision, thus these polls.
In particular:

>>  * What should be the primary separator in the syntax for Media 
>> Fragment URI? http://www.w3.org/2002/09/wbs/42785/MFRAGSYNTAXSEPARATOR/

We agree that the *secondary* separator would be the comma character 
(','). For example, in http://www.example.com/movie.mov#t=12.33,21.16 
the comma is used to separate the two time points that define the 
sequence to retrieve. We need to have a *primary* separator. For 
example, for selecting a track _and_ a temporal sequence in 

Question: What should be the primary separator?
Choices: '&' or ';'
I can't remember why Yves said he would almost prefer the semi-colon 
option ... Yves ?

>>  * How to define a rectangle region in the syntax for Media Fragment 
>> URI? http://www.w3.org/2002/09/wbs/42785/MFRAGSYNTAXRECTANGLE/

This is the traditional problem of defining a rectangle region. 
Providing 4 int is not enough, as people never know to which refer each 
value! We decide therefore to use a string that tells which value is what.

Question: Which string should be use?
Choices: xywh, trbl, tlbr, x1y1x2y2

Some are longer to type but clearer ... Note that trbl is the only one 
that prevents cropping an area that would be outside the image!

>>  * Are the quotes around track and id optional in the syntax for Media 
>> Fragments URI? http://www.w3.org/2002/09/wbs/42785/MFRAGSYNTAXQUOTE/

Among the 4 dimensions we are considering, two (track and id) will have 
as value a string of characters. If this string can be 
internationalized, then we need to quote them. If we just write 
identifiers (that contain no exotic characters), then the characters are 
un-necessary making the syntax heavier.

Question: Are the quotes around track and id optional?
Choices: optional (yes) or mandatory (no)

Does that help?
Best regards.


[1] http://www.w3.org/2008/WebVideo/Fragments/wiki/Syntax

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 Thursday, 22 January 2009 17:36:34 UTC

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