A/V desync with dv sample

[Carl Eugen Hoyos]

​http://thread.gmane.org/gmane.comp.video.ffmpeg.user/44228/focus=44465
A user uploaded a dv sample that plays fine with QuickTime and mplayer -demuxer rawdv, ffplay and ffmpeg show significant A/V desync. The reason are error codes in the dv stream that lead to incorrect timestamps. ffplay does not show any issues if seeking is used to skip the problematic parts of the stream.

$ ffmpeg -i error.dv -qscale 2 out.avi
ffmpeg version N-50600-g309d6f5 Copyright (c) 2000-2013 the FFmpeg developers
  built on Mar  8 2013 22:07:22 with gcc 4.7 (SUSE Linux)
  configuration: --enable-gpl --disable-indev=jack
  libavutil      52. 19.100 / 52. 19.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[dv @ 0x317ef40] Estimating duration from bitrate, this may be inaccurate
Input #0, dv, from 'error.dv':
  Metadata:
    timecode        : 01:09:48:11
  Duration: 00:01:00.03, start: 0.000000, bitrate: 28771 kb/s
    Stream #0:0: Video: dvvideo, yuv411p, 720x480 [SAR 8:9 DAR 4:3], 28771 kb/s, 29.97 tbr, 29.97 tbn, 29.97 tbc
    Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
Please use -q:a or -q:v, -qscale is ambiguous
Output #0, avi, to 'out.avi':
  Metadata:
    ISMP            : 01:09:48:11
    ISFT            : Lavf54.63.104
    Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 720x480 [SAR 8:9 DAR 4:3], q=2-31, 200 kb/s, 29.97 tbn, 29.97 tbc
    Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, fltp, 192 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (dvvideo -> mpeg4)
  Stream #0:1 -> #0:1 (pcm_s16le -> ac3)
Press [q] to stop, [?] for help
frame=  303 fps=0.0 q=2.0 size=    2521kB time=00:00:10.11 bitrate=2042.6kbits/s
[dvvideo @ 0x317f860] AC EOB marker is absent pos=64
[dvvideo @ 0x317f860]     Last message repeated 1 times
    Last message repeated 1 times
[dvvideo @ 0x317f860] AC EOB marker is absent pos=64
    Last message repeated 2 times
[dvvideo @ 0x317f860] AC EOB marker is absent pos=65
[dvvideo @ 0x317f860] AC EOB marker is absent pos=64
[dvvideo @ 0x317f860] AC EOB marker is absent pos=64
[dvvideo @ 0x317f860] AC EOB marker is absent pos=64
AC EOB marker is absent pos=64
[dvvideo @ 0x317f860] AC EOB marker is absent pos=66
    Last message repeated 2 times
[dvvideo @ 0x317f860] AC EOB marker is absent pos=65
    Last message repeated 1 times
[dvvideo @ 0x317f860] AC EOB marker is absent pos=75
    Last message repeated 1 times

...

[dvvideo @ 0x317f860] AC EOB marker is absent pos=64
[dvvideo @ 0x317f860] AC EOB marker is absent pos=64
[dvvideo @ 0x317f860] AC EOB marker is absent pos=65
[dvvideo @ 0x317f860] AC EOB marker is absent pos=64
[dvvideo @ 0x317f860] AC EOB marker is absent pos=69
    Last message repeated 6 times
frame=  875 fps=582 q=2.0 size=    7409kB time=00:00:29.19 bitrate=2078.8kbits/s
frame= 1662 fps=553 q=2.0 size=   20069kB time=00:00:55.45 bitrate=2964.7kbits/s
error.dv: Input/output error
frame= 1799 fps=546 q=2.0 Lsize=   23842kB time=00:01:00.02 bitrate=3253.8kbits/s
video:22347kB audio:1399kB subtitle:0 global headers:0kB muxing overhead 0.406532%

[Carl Eugen Hoyos]

Sample uploaded to ​http://samples.ffmpeg.org/ffmpeg-bugs/trac/ticket2340/

[Carl Eugen Hoyos]

Fixed by Michael in 88f038ac