- From: Yves Lafon <ylafon@w3.org>
- Date: Wed, 27 Aug 2008 05:44:15 -0400 (EDT)
- To: Martin Duerst <duerst@it.aoyama.ac.jp>
- cc: Larry Masinter <LMM@acm.org>, 'Lisa Dusseault' <lisa@osafoundation.org>, 'Julian Reschke' <julian.reschke@gmx.de>, 'Mark Nottingham' <mnot@mnot.net>, 'HTTP Working Group' <ietf-http-wg@w3.org>
On Fri, 22 Aug 2008, Martin Duerst wrote:
>
> At 18:48 08/08/08, Larry Masinter wrote:
>>
>> There is a new W3C working group proposed for working on addressing
>> and accessing temporal fragments of timed media (video & audio).
>> One could imagine time ranges that might be independent of the
>> format.
>>
>> On the other hand, I don't understand the reasons that the
>> JPEG 2000 committee rejected using HTTP range retrieval for
>> the J2 protocol, instead adopting query parameters in the URLs.
>> In this case, the range retrieval might look like it was
>> media independent even though J2 defined it specifically for
>> JPEG 2000 encoded images.
>>
>> It might be worth looking into the reasons for the design
>> choice in J2.
>
> I have no clue, but it could be that one argument for not using
> ranges is that you cannot expose them in an URI. This means that
> instead of sending your colleague a mail saying "Look at this
> interesting snippet: [URI here]" you have to say "Look at this
> video [URI here], the interesting stuff is at xx:yy:zz into the
> video".
Well, when fragments are used to identify part of an HTML document, the
fragment is not sent at the HTTP level, although in the case of HTML the
whole document is always fetched, but in the case of pictures or video,
being able to access a part of the image using ranges derived form the URI
instead of dowloading the whole document before finding the fragment would
be far more efficient (like accessing XMP fragment inside a picture, 10s
out of a 1h movie in fullHD).
--
Baroula que barouleras, au tiéu toujou t'entourneras.
~~Yves
Received on Wednesday, 27 August 2008 09:44:48 UTC