W3C home > Mailing lists > Public > public-media-fragment@w3.org > May 2011

Re: Temporal media fragment for HTML media questions

From: Chris Double <cdouble@mozilla.com>
Date: Tue, 10 May 2011 20:39:59 +1200
Message-ID: <BANLkTi=K-DkhCwY77UU6jx2Cv35oHNfsHw@mail.gmail.com>
To: Media Fragment <public-media-fragment@w3.org>
On Tue, May 10, 2011 at 8:08 PM, Philip Jägenstedt <philipj@opera.com> wrote:
>> 1) When a temporal fragment is given with a start time, when the
>> loadedmetadata event on the resource is raised this is the currentTime
>> of the resource.
> Do you mean that you internally seek when reaching HAVE_METADATA? That's
> what I did, but care must be taken to not show the first frame of the video
> before seeking. Also, should seeking events be fired at this point?

I internally seek after I've read the metadata from the resource, then
raise HAVE_METADATA when the seek is complete. I don't fire the
seeking events. Would it be better to do HAVE_METADATA, then seek and
raise the usual seeking events?

>> 2) When an end time is given I do the equivalent of calling 'pause()'
>> on the media element. I do not raise the 'ended' event.
> Is paused set to true, or is the element "paused for user interaction"? I
> think the latter actually makes sense, but when I implemented MF as a quick
> hack for FOMS I just called pause().

It behaves exactly as if the 'pause()' method was called on the media
element, so 'paused' is set to true. I think this makes it easier for
controls to stay in sync with what's happening.

> 3. Don't support looping.
> I think option 3 is the least horrible option.

I'll be doing this for the first implementation anyway since we don't
yet support the loop attribute. I was curious for the case when we do
support it though.

>> 5) When a user seeks, or 'currentTime' is set on the DOM object then
>> the media fragments are ignored. Is this the right approach? Or should
>> seeks within the fragment range not remove the fragments?
> What does "remove the fragments" mean?

By 'remove the fragments' I mean the resource no longer has the
start/end range that playback is clipped too. The user interface no
longer shows it, etc. Since there's no way to say 'play me only the
fragment' once fragment play back is completed, or the user seeks
outside of it, I thought I'd just remove any indicators of the

> Please have a look at http://www.w3.org/Bugs/Public/show_bug.cgi?id=10723
> and weigh in with whatever you think makes sense.

Will do, thanks.

> Finally, whatever you end up implementing, I would very much appreciate if
> you take the time to ensure that it ends up in the specs as well, either MF
> of HTML.

I'll do this as well,

Received on Tuesday, 10 May 2011 08:46:55 UTC

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