[whatwg] Exposing framerate / statistics of <video> playback and related feedback
chuck at jumis.com
Tue May 1 10:35:35 PDT 2012
On 5/1/12 10:21 AM, Hugh Guiney wrote:
>> > If you have fixed frame rates, it's trivial to do the conversion to and
>> > the media element API.
> Yes, but we currently have no way of knowing what fixed frame rate we
> are working with, making this kind of conversion impossible except
> through pure guesswork. If frame rate is exposed we don't need SMPTE
The frame rate issue seems to have come up with media capture as well.
The list looked at having a (canvas) ctx.stream = mediaElement; option
to better copy frames from a media stream into Canvas. I don't think
that the assignment operator will work, but it does seem like we could
optimize our drawImage calls to only happen when needed. At present, we
simply would run requestAnimationFrame. But, if a video stream is
operating on a slower frame rate than rAF, then the drawImage + rAF
method will be wasteful.
I've suggested an onframeready event; it seems as though that event
could also carry the number of dropped frames.
All that said, I'm a little behind on the media tags, so apologies if
I've missed some already existing mechanisms.
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