[FFmpeg-user] strange h264 framerate diagnostics

[Christian Ebert]

Hi,

Here, even with explicit "-r 25" (shouldn't be needed, as source
is 25fps) and following sample cmdline:

$ ffmpeg -i test.mov -vcodec libx264 -vpre normal \
-acodec libfaac -ac 1 -ar 22050 -ac 1 -ab 40k -r 25 -y test.mp4

a check gives codec frame rate differs from container frame rate!

$ ffmpeg -i test.mp4
FFmpeg version SVN-r17657, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --enable-gpl --enable-nonfree --disable-network --disable-ffserver --disable-vhook --disable-ffplay --enable-shared --enable-pthreads --enable-postproc --enable-swscale --enable-libfaad --enable-libfaac --enable-libx264 --enable-libxvid --enable-libmp3lame --extra-cflags=-I/sw/include --extra-libs=-L/sw/lib
  libavutil     49.15. 0 / 49.15. 0
  libavcodec    52.20. 0 / 52.20. 0
  libavformat   52.30. 1 / 52.30. 1
  libavdevice   52. 1. 0 / 52. 1. 0
  libswscale     0. 7. 1 /  0. 7. 1
  libpostproc   51. 2. 0 / 51. 2. 0
  built on Feb 28 2009 15:04:37, gcc: 4.0.1 (Apple Inc. build 5490)

Seems stream 0 codec frame rate differs from container frame rate: 25.00 (25/1) -> 12.50 (25/2)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mp4':
  Duration: 00:04:22.04, start: 0.000000, bitrate: 243 kb/s
    Stream #0.0(eng): Video: h264, yuv420p, 720x576, 12.50 tbr, 25 tbn, 25 tbc
    Stream #0.1(eng): Audio: aac, 22050 Hz, mono, s16
At least one output file must be specified

QuickTime reports 25 fps. And the movie plays fine.

I just would like to know what's going on.

$ x264 --version
x264 0.66.1115 11863ac
built on Feb 28 2009, gcc: 4.0.1 (Apple Inc. build 5490)

c
-- 
\black\trash movie    _C O W B O Y_  _C A N O E_  _C O M A_
Ein deutscher Western/A German Western
-->> http://www.blacktrash.org/underdogma/ccc.html
-->> http://www.blacktrash.org/underdogma/ccc-en.html