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Re: Media Fragment URI Syntax: 3 polls now open

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Mon, 26 Jan 2009 15:58:45 +1100
Message-ID: <2c0e02830901252058y6bdff0dclcfbd03fb853ff4f@mail.gmail.com>
To: RaphaŽl Troncy <Raphael.Troncy@cwi.nl>
Cc: Dave Singer <singer@apple.com>, Media Fragment <public-media-fragment@w3.org>

Hi all,

On Fri, Jan 23, 2009 at 4:35 AM, RaphaŽl Troncy <Raphael.Troncy@cwi.nl> wrote:
>>>  * 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.

I would be really careful about using the comma as a secondary
separator. There are time specifications that include a comma, in
particular the SMPTE time stamps. Any number that is larger than 1000
is often specified as 1,000. These are the reasons why in Temporal
URIs we did not use the comma as the secondary separator, but rather
used the "/". I seem to have missed that discussion in Ghent and the
agreement on the comma. If people think this situation can be avoided,
then I'm happy to consent to the comma - it certainly feels natural.

> We need to have a *primary* separator. For example, for selecting a track
> _and_ a temporal sequence in
> http://www.example.com/movie.mov#track='audio1'&t=12.33,21.16
>
> 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!

I think there is a mistake on the
http://www.w3.org/2002/09/wbs/42785/MFRAGSYNTAXRECTANGLE/ page.
The one used by CSS is not xywh, FAIK, but is trbl - see e.g.
http://www.css3.com/css-margin/ .
So, I think this question has to be corrected and re-asked.


>>>  * 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)

According to http://www.ietf.org/rfc/rfc3986.txt, if we are using
quotes, it can only be single quotes. Double quotes are not allowed
inside a fragment, FAICT. I think double quotes need to be
percent-encoded. So, we should change the question to say
single-quotes rather than double-quotes.

Cheers,
Silvia.
Received on Monday, 26 January 2009 04:59:22 GMT

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