[FFmpeg-trac] #1180(undetermined:new): video cutting/extraction leads to various a/v sync (when possible)

[FFmpeg]

#1180: video cutting/extraction leads to various a/v sync (when possible)
-------------------------------------+-------------------------------------
               Reporter:  ubitux     |                  Owner:
                   Type:  defect     |                 Status:  new
               Priority:  normal     |              Component:
                Version:             |  undetermined
  unspecified                        |               Keywords:
             Blocked By:             |               Blocking:
Reproduced by developer:  0          |  Analyzed by developer:  0
-------------------------------------+-------------------------------------
 Using a random AVI (http://samples.ffmpeg.org/avi/GoneNutty.avi) and
 trying to extract a scene leads to various a/v sync issues:

 {{{
 % ./ffmpeg -i ~/samples/GoneNutty.avi -ss 120 -c copy -y cut.avi
 ffmpeg version N-39647-g1d13032 Copyright (c) 2000-2012 the FFmpeg
 developers
   built on Apr  9 2012 17:52:37 with gcc 4.7.0 20120324 (prerelease)
   configuration: --enable-libfreetype --enable-gpl --enable-libmp3lame
 --enable-libvorbis --enable-libxvid --enable-libx264 --enable-libvpx
 --enable-libtheora --enable-x11grab --enable-libopenjpeg --enable-libass
 --enable-libmodplug
   libavutil      51. 45.100 / 51. 45.100
   libavcodec     54. 14.100 / 54. 14.100
   libavformat    54.  3.100 / 54.  3.100
   libavdevice    53.  4.100 / 53.  4.100
   libavfilter     2. 67.101 /  2. 67.101
   libswscale      2.  1.100 /  2.  1.100
   libswresample   0. 10.100 /  0. 10.100
   libpostproc    52.  0.100 / 52.  0.100
 [mpeg4 @ 0x1aed720] Invalid and inefficient vfw-avi packed B frames
 detected
 Input #0, avi, from '/home/ubitux/samples/GoneNutty.avi':
   Metadata:
     encoder         : Nandub v1.0rc2
   Duration: 00:04:38.84, start: 0.000000, bitrate: 1345 kb/s
     Stream #0:0: Video: mpeg4 (DX50 / 0x30355844), yuv420p, 640x352 [SAR
 1:1 DAR 20:11], 25 fps, 25 tbr, 25 tbn, 30k tbc
     Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, s16,
 192 kb/s
 Output #0, avi, to 'cut.avi':
   Metadata:
     ISFT            : Lavf54.3.100
     Stream #0:0: Video: mpeg4 (DX50 / 0x30355844), yuv420p, 640x352 [SAR
 1:1 DAR 20:11], q=2-31, 25 fps, 25 tbn, 25 tbc
     Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, 192
 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (copy)
   Stream #0:1 -> #0:1 (copy)
 Press [q] to stop, [?] for help
 frame= 3879 fps=0.0 q=-1.0 Lsize=   23751kB time=00:02:38.84
 bitrate=1224.9kbits/s
 video:19808kB audio:3723kB global headers:0kB muxing overhead 0.935748%
 }}}

 Playback results with different players:

 - ffplay: invalid frame rate, playback mostly broken
 - MPlayer: no video is displayed for a few seconds, and then video starts
 (with -correct-pts the video is freezed for a while)
 - VLC: samples rate seems insanely high, no video at first, then the video
 starts, and sounds is still way too fast
 - mplayer2: seems to actually deal with it pretty well

 Even though mplayer2 seems to handle it, I believe the file is broken and
 something should be fixed.

 Note: specifying -ss before the input doesn't work:

 {{{
 ./ffmpeg -ss 120 -i ~/samples/GoneNutty.avi -c copy -y cut2.avi
 ffmpeg version N-39647-g1d13032 Copyright (c) 2000-2012 the FFmpeg
 developers
   built on Apr  9 2012 17:52:37 with gcc 4.7.0 20120324 (prerelease)
   configuration: --enable-libfreetype --enable-gpl --enable-libmp3lame
 --enable-libvorbis --enable-libxvid --enable-libx264 --enable-libvpx
 --enable-libtheora --enable-x11grab --enable-libopenjpeg --enable-libass
 --enable-libmodplug
   libavutil      51. 45.100 / 51. 45.100
   libavcodec     54. 14.100 / 54. 14.100
   libavformat    54.  3.100 / 54.  3.100
   libavdevice    53.  4.100 / 53.  4.100
   libavfilter     2. 67.101 /  2. 67.101
   libswscale      2.  1.100 /  2.  1.100
   libswresample   0. 10.100 /  0. 10.100
   libpostproc    52.  0.100 / 52.  0.100
 [mpeg4 @ 0x2857720] Invalid and inefficient vfw-avi packed B frames
 detected
 Input #0, avi, from '/home/ubitux/samples/GoneNutty.avi':
   Metadata:
     encoder         : Nandub v1.0rc2
   Duration: 00:04:38.84, start: 0.000000, bitrate: 1345 kb/s
     Stream #0:0: Video: mpeg4 (DX50 / 0x30355844), yuv420p, 640x352 [SAR
 1:1 DAR 20:11], 25 fps, 25 tbr, 25 tbn, 30k tbc
     Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, s16,
 192 kb/s
 Output #0, avi, to 'cut2.avi':
   Metadata:
     ISFT            : Lavf54.3.100
     Stream #0:0: Video: mpeg4 (DX50 / 0x30355844), yuv420p, 640x352 [SAR
 1:1 DAR 20:11], q=2-31, 25 fps, 25 tbn, 25 tbc
     Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, 192
 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (copy)
   Stream #0:1 -> #0:1 (copy)
 Press [q] to stop, [?] for help
 [avi @ 0x2858fe0] Application provided invalid, non monotonically
 increasing dts to muxer in stream 1: -14 >= -14
 av_interleaved_write_frame(): Invalid argument
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1180>
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