[whatwg] How to handle multitrack media resources in HTML
watsonm at netflix.com
Mon Apr 11 09:12:07 PDT 2011
Sent from my iPhone
On Apr 11, 2011, at 8:55 AM, "Eric Carlson" <eric.carlson at apple.com> wrote:
> On Apr 10, 2011, at 12:36 PM, Mark Watson wrote:
>> In the case of in-band tracks it may still be the case that they are retrieved independently over the network. This could happen two ways:
>> - some file formats contain headers which enable precise navigation of the file, for example using HTTP byte ranges, so that the tracks could be retrieved independently. mp4 files would be an example. I don't know that anyone does this, though.
> QuickTime has supported tracks with external media samples in .mov files for more than 15 years. This type of file is most commonly used during editing, but they are occasionally found on the net.
I was also thinking of a client which downloads the MOOV box and then uses the tables there to construct byte range requests for specific tracks.
>> - in the case of adaptive streaming based on a manifest, the different tracks may be in different files, even though they appear as in-band tracks from an HTML perspective.
>> In these cases it *might* make sense to expose separate buffer and network states for the different in-band tracks in just the same way as out-of-band tracks.
> I strongly disagree. Having different tracks APIs for different container formats will be extremely confusing for developers, and I don't think it will add anything. A UA that chooses to support non-self contained media files should account for all samples when reporting readyState and networkState.
Fair enough. I did say 'might' :-)
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