[FFmpeg-devel] [PATCH 1/2] mxfenc: factorize samples per frame code

Ben Jackson ben at ben.com
Thu Sep 13 01:52:44 CEST 2012


On Thu, Sep 13, 2012 at 01:22:02AM +0200, Matthieu Bouron wrote:
> On Thu, Sep 13, 2012 at 1:09 AM, Kieran Kunhya <kierank at ob-encoder.com>wrote:
> 
> > > +    { { 1001, 60000 }, { 801,  801,  801,  801,  800,  0 } }, // NTSC
> > 59.94
> >
> > I thought the pattern was:
> > {  801,  800,  801,  801,  801 }
> >
> > I've never found a spec for this though - found it in a document
> > somewhere so you might be right.

The particular cadence doesn't matter.  It just needs to average 800.8
over 10 fields.  At a frame level it typically does not diverge beyond
1600 to 1602 (although obviously 1601 and 1602 are all that are strictly
necessary).

I might be able to dig up the relevant SMPTE spec but it's not so specific
as to give a pattern.

-- 
Ben Jackson AD7GD
<ben at ben.com>
http://www.ben.com/


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