[whatwg] HTML5 video: frame accuracy / SMPTE

Rob Coenen coenen.rob at gmail.com
Tue Jan 11 14:20:30 PST 2011

Chris, maybe I'm wording it incorrect, but when I run the mediainfo utility
on my test file it reports "frame rate: 25.000 fps"
(test for yourself with my test file:

I can imagine there are 'virtual' frames, where say frame 1 to 10 is
actually the same frame and internally encoded as frame 1 with a duration of
10 frames?

Even then I'd like the 'virtual' FPS of the WebM file exposed to the
webbrowser- similar to how my other utilities report a FPS.

This way one could build web-tools in HTML5 that allow to access each
individual frame and do other things than simply playing back the movie in a
linear fashion from beginning to end.


On Tue, Jan 11, 2011 at 10:05 PM, Chris Pearce <chris at pearce.org.nz> wrote:

> On 12/01/2011 10:58 a.m., Rob Coenen wrote:
>> Intresting- I didn't know that variable frame-rate videos were actually
>> being used for HTML5 video.
> WebM videos have no fixed frame rate. This format is supported in Firefox
> 4, Chrome, and Opera.
> Chris P.

More information about the whatwg mailing list