[whatwg] VIDEO Timeupdate event frequency.

Tab Atkins Jr. jackalmage at gmail.com
Fri Sep 10 10:07:02 PDT 2010

On Fri, Sep 10, 2010 at 9:58 AM, Simon Fraser <smfr at me.com> wrote:
> The problem with a 'newFrame' callback is what to do if the callback
> takes longer than the duration of a single frame. Does the video engine
> start dropping frames, or does the video lag?

Dropping frames would be the better solution, for all the uses I'd put
it to.  (Or rather, dropping newFrame events.)

> In WebKit on Mac, video playback is hardware-accelerated, and the
> presentation of video frames is disconnected from the web page
> drawing machinery. A newFrame callback would force us to drop
> back into software rendering, which is significantly more CPU intensive.
> I don't support the general use of a 'newFrame' callback except in
> the context of video processing via canvas.

In general, video processing via canvas is going to require dropping
into software rendering, right?  I think that's what I was hearing
from our dudes putting hardware-accelerated video into Chrome.  So at
least in the case that I can see this often being put towards, you
don't lose anything.


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