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[whatwg] HTML5 video: frame accuracy / SMPTE

From: Dirk-Willem van Gulik <Dirk-Willem.van.Gulik@BBC.co.uk>
Date: Wed, 12 Jan 2011 00:42:22 +0000
Message-ID: <65DB7C4F-418D-42C2-89F9-8EA792FA6783@BBC.co.uk>

On 11 Jan 2011, at 23:46, Kevin Marks wrote:

> These goals are orthogonal though - stepping between frames is valuable
> whether they are regularly spaced or not.
> 
> Timecode is a representation that comes from the legacy video world that
> does assume a uniform frame rate

Not sure if they are orthogonal though. If you can step and know the exact (wall clock time) of that step - one can take the rest from there. Keep in mind that the purpose here is to be able to exactly reference some specific point.

And while the literally cutting between two cells on an old celluloid film is gone; the concept of having a subtitle start at moment X or a fade in completing at Y is still equally valid. And for artistic & technical reasons it is often good to be able to sync these with the concept of the frame making it to the 'screen'; and having such happen in 'one pass' not interrupted by some refresh visible to the eye (i.e. the whole interlace issue, elongated footballs, seeing suddenly 2 tennisballs in the game etc).

Dw
Received on Tuesday, 11 January 2011 16:42:22 UTC

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