[whatwg] VIDEO Timeupdate event frequency.
Eric Carlson
eric.carlson at apple.com
Fri Sep 10 20:23:49 PDT 2010
On Sep 10, 2010, at 8:06 PM, Biju wrote:
> On Fri, Sep 10, 2010 at 7:05 AM, Silvia Pfeiffer
> <silviapfeiffer1 at gmail.com> wrote:
>> Incidentally: What use case did you have in mind, Biju ?
>
> I was thinking about applications like
> https://developer.mozilla.org/samples/video/chroma-key/index.xhtml
> ( https://developer.mozilla.org/En/Manipulating_video_using_canvas )
>
> Now it is using setTimeout so if processor is fast it will be
> processing same frame more than on time. Hence wasting system
> resource, which may affect other running process.
>
Perhaps, but it only burns cycles on those pages instead of burning cycles on *every* page that uses a <video> element.
> If we use timeupdate event we may be missing some frames as timeupdate
> event is only happen every 200ms or 250ms, ie 4 or 5 frames per
> second.
>
Even in a browser that fires 'timeupdate' every frame, you *will* miss frames on a heavily loaded machine because the event is fired asynchronously.
> And we know there are videos which a have more than 5 frames per second.
>
So use a timer if you know that you want update more frequently.
eric
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