- From: Charles Pritchard <chuck@jumis.com>
- Date: Tue, 01 May 2012 10:35:35 -0700
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 >> > from SMTPE timecode in JavaScript; you don't need any direct support from >> > 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 > internally. 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. -Charles
Received on Tuesday, 1 May 2012 10:35:35 UTC