[FFmpeg-devel] Change in ffmpeg's frame rate mismatch handling policy ?

[Alexandre Ferrieux]

Hi,

I observe what looks like a change in ffmpeg's policy regarding how to 
handle frame rate mismatches between codec and container:


Recent version:
---------------

% ./ffmpeg -r 15 -i rcs.h263 -r 24 rcs3.ts

FFmpeg version SVN-r18705, Copyright (c) 2000-2009 Fabrice Bellard, et al.

Input #0, h263, from 'rcs.h263':
   Duration: N/A, bitrate: N/A
     Stream #0.0: Video: h263, yuv420p, 176x144 [PAR 12:11 DAR 4:3], 
29.97 tbr, 1200k tbn, 29.97 tbc

Older version:
--------------

% ffmpeg -r 15 -i rcs.h263 -r 24 rcs3.ts

FFmpeg version SVN-r16495, Copyright (c) 2000-2009 Fabrice Bellard, et al.

Seems stream 0 codec frame rate differs from container frame rate: 29.97 
(30000/1001) -> 15.00 (15/1)
Input #0, h263, from 'rcs.h263':
   Duration: N/A, bitrate: N/A
     Stream #0.0: Video: h263, yuv420p, 176x144 [PAR 12:11 DAR 4:3], 
15.00 tb(r)



The above comparison is made on the very same input raw H263 file 
captured at 15fps. In both cases a TS is produced, but in the recent 
version of ffmpeg it is playing twice too fast (because it is 
subsampling the input stream based on the assumption that it was 29.97fps).

Questions:

  - is the disparition of the warning about frame rates intentional ?
  - is there a way in the recent (svn 18705) ffmpeg to  override the 
detected/assumed 29.97fps rate ? It seems the "-r 15" is ignored.

TIA,

-Alex