[Ffmpeg-devel] Re: incorrect NTSC frame rate detection in .MOV file parser

[Baptiste COUDURIER]

Dan Maas wrote:
>>>For example, a 2-frame NTSC DV Quicktime file has total duration 5994
>>>and sample duration 200. The correct frame rate is 5994/200 = 2997/100.
>>>However the av_reduce() returns 30/1, which is incorrect.
>>
>>2997/100 is incorrect too
> 
> 
> I know... But that's what Final Cut Pro puts in the file.
> 
> I'd be happy with either 2997/100 or 30000/1001. But definitely not
> 30/1!
> 
> 
>>anyway, cvs up and ffmpeg will guess better
> 

Usual frame rates from FCP are : timescale 2500 and stts sample duration
to 100 for PAL and timescale 2997 and stts sample duration to 100 for
NTSC. Computing fps from stts and timscale gives correct framerate.

But MOV is really a pain in the ass talking about framerate :>

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
SMARTJOG S.A.                                    http://www.smartjog.com
Key fingerprint                 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
Phone: +33 1 49966312