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Re: Range syntax

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Fri, 11 Sep 2009 19:20:59 +1000
Message-ID: <2c0e02830909110220o2b78068p2170816e3ef4ca20@mail.gmail.com>
To: RaphaŽl Troncy <Raphael.Troncy@cwi.nl>
Cc: Jack Jansen <Jack.Jansen@cwi.nl>, Yves Lafon <ylafon@w3.org>, Davy Van Deursen <davy.vandeursen@ugent.be>, public-media-fragment@w3.org
2009/9/11 RaphaŽl Troncy <Raphael.Troncy@cwi.nl>

> Hi Silvia,
>  We could take a different approach where we specify the type of addressing
>> as well as the format, e.g.
>> Content-Range: time:smpte-30-drop 1:22:33-2:33:44.1/4:00:00
>> (or just "t" instead of "time") and similarly
>> Content-Range: time:npt 82:33-153:44.1/4:00:00
> Yes, but then it breaks the "bytes" scheme where no dimension is provided.

No, it doesn't. There is no requirement on how the scheme is defined.
"bytes" will continue to stay "bytes".

> What is the added value of adding the dimensions (time, xywh) other the
> units (npt, smpte, pixel)?

You know what dimension you're dealing with and it's extensible and it's the
same as what we're defining for the URIs.

I like also the idea of having a clear mechanism to advert the wished units
> (rather than dimensions) using Accept-Ranges.

Yes, that's possible, too.

>  Content-Range: xywh 160,120,320,240/4:00:00
>> Content-Range: xywh:pixel 160,120,320,240/4:00
>> Content-Range: xywh:percent 25,25,50,50/4:00
>> Content-Range: track 'video'/4:00
>> Content-Range: id 'chapter-1'/4:00
> Assuming you haven't done any copy/paste errors in the above examples, do
> you mean that the instance length (the value on the right side of the '/')
> should always been the temporal duration of the whole media?

I wasn't much thinking about that part of the specification when I wrote it.
I replied to Franck's suggestion with an "I agree". :-)

> It makes sense for id.

I am actually hesitant to say what makes sense for id, since it could
specify any of the other dimensions. So, maybe id should only be a request
parameter, but should be combined in a response with the actual dimension
that it ranges on?

> For track, I guess it could be the duration of the selected track. For
> space, I really don't know ...
> Thoughts?

See earlier email.


> Cheers.
>  RaphaŽl
> --
> RaphaŽl Troncy
> EURECOM, Multimedia Communications Department
> 2229, route des CrÍtes, 06560 Sophia Antipolis, France.
> e-mail: raphael.troncy@eurecom.fr & raphael.troncy@gmail.com
> Tel: +33 (0)4 - 9300 8242
> Fax: +33 (0)4 - 9000 8200
> Web: http://www.cwi.nl/~troncy/ <http://www.cwi.nl/%7Etroncy/>
Received on Friday, 11 September 2009 09:22:08 GMT

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