Re: Notify user agent available fragment

On Tue, May 4, 2010 at 1:46 AM, Eric Carlson <> wrote:
> On May 3, 2010, at 6:00 AM, RaphaŽl Troncy wrote:
>>> How do you see the user-agent being notified in advance of the
>>> fragmentation possibilities of a certain resource?
>> As Jack said, this is the problem of discovery, and as Davy rightly pointed out, if you are concerned of how a UA can know in advance which tracks (if any) are available in a media resource, then there are at least two ways:
>> †- use the Media Multitrack Javascript API developed by the accessibility task force of the HTML5 WG,
> †I don't think this will work as the UA will not be able to answer a priori questions about the composition of a media resource. The multitrack API will only work once the media element's readyState reaches HAVE_METADATA, which requires the UA to have loaded enough of the resource to know its duration, dimensions, etc. [1].
> [1]

Incidentally, reaching the HAVE_METADATA state will also be a
precursor to some of the cases that the MF spec identifies, such as:
. Thus it's not unreasonable to deal with this condition for certain
usage cases.

But I agree there needs to be a different means of discovery, too. The
ROE example of Davy deals with this situation well.


Received on Tuesday, 4 May 2010 01:23:16 UTC