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

[Kieran Kunhya]

On Thu, Sep 13, 2012 at 12:52 AM, Ben Jackson <ben at ben.com> wrote:
> 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.

It's more of a question as to whether tools on the market will
complain/crash/cause the apocalypse unless you use a pattern that it
likes.