[FFmpeg-user] force frame rate when reformating raw h264 stream

[Jan Pohanka]

Again with current fresh compiled version

Dne Mon, 01 Oct 2012 11:30:29 +0200 Carl Eugen Hoyos <cehoyos at ag.or.at>  
napsal(a):

> Please provide the output for current git head...

Current ffplay informs about 2.50 fps, but the playing speed is correct (5  
fps and video length 15s)

# ffplay a.h264
ffplay version N-44937-gadc5539 Copyright (c) 2003-2012 the FFmpeg  
developers
   built on Oct  1 2012 11:42:51 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
   configuration: --enable-libx264 --enable-gpl --prefix=/opt/ffmpeg
   libavutil      51. 73.101 / 51. 73.101
   libavcodec     54. 61.100 / 54. 61.100
   libavformat    54. 29.105 / 54. 29.105
   libavdevice    54.  3.100 / 54.  3.100
   libavfilter     3. 18.100 /  3. 18.100
   libswscale      2.  1.101 /  2.  1.101
   libswresample   0. 16.100 /  0. 16.100
   libpostproc    52.  1.100 / 52.  1.100
[h264 @ 0x7f87d40008c0] max_analyze_duration 5000000 reached at 5200000
[h264 @ 0x7f87d40008c0] Estimating duration from bitrate, this may be  
inaccurate
Input #0, h264, from 'a.h264':
   Duration: N/A, bitrate: N/A
     Stream #0:0: Video: h264 (High), yuvj420p, 800x608, 2.50 fps, 2.50  
tbr, 1200k tbn, 5 tbc
Frame changed from size:0x0 to size:800x608B vq=   25KB sq=    0B f=0/0
   15.51 A-V:  0.000 fd=   0 aq=    0KB vq=    0KB sq=    0B f=0/0   0/0

Muxing to mkv also informs about 2.50 fps ...

# ffmpeg -r 5 -i a.h264 -vcodec copy -f matroska -r 5 -y btest.mkv
ffmpeg version N-44937-gadc5539 Copyright (c) 2000-2012 the FFmpeg  
developers
   built on Oct  1 2012 11:42:51 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
   configuration: --enable-libx264 --enable-gpl --prefix=/opt/ffmpeg
   libavutil      51. 73.101 / 51. 73.101
   libavcodec     54. 61.100 / 54. 61.100
   libavformat    54. 29.105 / 54. 29.105
   libavdevice    54.  3.100 / 54.  3.100
   libavfilter     3. 18.100 /  3. 18.100
   libswscale      2.  1.101 /  2.  1.101
   libswresample   0. 16.100 /  0. 16.100
   libpostproc    52.  1.100 / 52.  1.100
[h264 @ 0x3001320] max_analyze_duration 5000000 reached at 5200000
[h264 @ 0x3001320] Estimating duration from bitrate, this may be inaccurate
Input #0, h264, from 'a.h264':
   Duration: N/A, bitrate: N/A
     Stream #0:0: Video: h264 (High), yuvj420p, 800x608, 2.50 fps, 2.50  
tbr, 1200k tbn, 5 tbc
Output #0, matroska, to 'btest.mkv':
   Metadata:
     encoder         : Lavf54.29.105
     Stream #0:0: Video: h264, yuvj420p, 800x608, q=2-31, 2.50 fps, 1k tbn,  
5 tbc
Stream mapping:
   Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
frame=   76 fps=0.0 q=-1.0 Lsize=     789kB time=00:00:29.84 bitrate=  
216.5kbits/s
video:787kB audio:0kB subtitle:0 global headers:0kB muxing overhead  
0.169792%

And the resulting file is played also on 2.50 fps, but this is not what I  
need. Now ffplay behaves correctly, because 2.50 fps is set in the  
matroska container, but previous ffmpeg command should set it to 5.

ffplay btest.mkv
ffplay version N-44937-gadc5539 Copyright (c) 2003-2012 the FFmpeg  
developers
   built on Oct  1 2012 11:42:51 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
   configuration: --enable-libx264 --enable-gpl --prefix=/opt/ffmpeg
   libavutil      51. 73.101 / 51. 73.101
   libavcodec     54. 61.100 / 54. 61.100
   libavformat    54. 29.105 / 54. 29.105
   libavdevice    54.  3.100 / 54.  3.100
   libavfilter     3. 18.100 /  3. 18.100
   libswscale      2.  1.101 /  2.  1.101
   libswresample   0. 16.100 /  0. 16.100
   libpostproc    52.  1.100 / 52.  1.100
Input #0, matroska,webm, from 'btest.mkv':
   Metadata:
     ENCODER         : Lavf54.29.105
   Duration: 00:00:30.04, start: 0.000000, bitrate: 215 kb/s
     Stream #0:0: Video: h264 (High), yuvj420p, 800x608, SAR 1:1 DAR 25:19,  
2.50 fps, 2.50 tbr, 1k tbn, 5 tbc (default)
Frame changed from size:0x0 to size:800x608B vq=   25KB sq=    0B f=0/0
   30.88 A-V:  0.000 fd=   0 aq=    0KB vq=    0KB sq=    0B f=0/0   0/0


> Can you share the sample?

I'm not sure about attachments in the list so the file can be downloaded  
on this link:
http://neuron.feld.cvut.cz/honza/a.h264

Jan