- From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
- Date: Mon, 20 Oct 2014 22:39:23 +1100
- To: Cyril Concolato <cyril.concolato@telecom-paristech.fr>
- Cc: "<public-html-media@w3.org>" <public-html-media@w3.org>
On Mon, Oct 20, 2014 at 9:45 PM, Cyril Concolato <cyril.concolato@telecom-paristech.fr> wrote: > Le 20/10/2014 06:28, Silvia Pfeiffer a écrit : >> >> Hi all, >> >> As a Web Developer, it's very nice to have the byte stream format >> registry http://www.w3.org/2013/12/byte-stream-format-registry/ , >> which defines MIME types and other useful information. >> >> The first thing I'm going to do when loading segments for media >> resources is to load an initialization segment. This usually happens >> with an XHR and a byte range. > > Small comments here: > - For live profiles of DASH, that is not the case. You'd have separate > initialization segment files. > - Then, for DASH on-demand profiles, you don't necessarily have to make a > single XHR. You can keep making multiple XHR, until you get track > information. Ok, sure. > Of course, having the IS size from the beginning would reduce > the number of requests and latency. That's all I'm trying to figure out here: some hint on what would be sensible. >> Would it be possible to make a recommendation for each one of the >> registered byte stream formats of how large a byte range one should >> request to ascertain retrieving the Initialization Segment for >> different formats? That would be really useful to developers. > > For the ISOBMFF, the size depends almost linearly on the number of tracks in > the IS. Also the size is theoretically unlimited because you may have > unlimited textual information (copyright, user information ...) or other > boxes. In practice, you can check some files here: > http://download.tsi.telecom-paristech.fr/gpac/DASH_CONFORMANCE/TelecomParisTech/, > you'll see that the IS rarely exceed 1 or 2 KB. But I'm not sure this should > be a recommendation. OK, that's a good start, thanks. Knowing that it depends n the number of tracks is good information to know, too. Thanks, Silvia.
Received on Monday, 20 October 2014 11:40:10 UTC