[FFmpeg-trac] #507(undetermined:new): Initial A/V desync when remuxing or transcoding ASP / MP3 in avi

[FFmpeg]

#507: Initial A/V desync when remuxing or transcoding ASP / MP3 in avi
-------------------------------------+-------------------------------------
               Reporter:  cehoyos    |                  Owner:
                   Type:  defect     |                 Status:  new
               Priority:  normal     |              Component:
                Version:  git-       |  undetermined
  master                             |               Keywords:
             Blocked By:             |               Blocking:
Reproduced by developer:  1          |  Analyzed by developer:  0
-------------------------------------+-------------------------------------
 http://www.datafilehost.com/download-eedefa35.html

 The sample plays fine with ffplay and MPlayer, if remuxed (to avi) or
 transcoded, the resulting video shows constant A/V desync (audio too
 early) from the beginning.

 The following scenes can be used to see the desync:
 ~  65 seconds: A trigger is pulled and a light ignites
 ~ 110 seconds: Footsteps can be heard and seen
 And from 120 seconds on

 out.avi shows ~1 second desync:
 {{{
 $ ffmpeg -i avdesync.avi -qscale 2 -r 24000/1001 -t 145 out.avi
 ffmpeg version N-32916-g73a5287, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Sep 25 2011 12:04:12 with gcc 4.5.3
   configuration: --enable-libvpx --enable-libvorbis
 --cc=/usr/local/gcc-4.5.3/bin/gcc
   libavutil    51. 17. 0 / 51. 17. 0
   libavcodec   53. 17. 0 / 53. 17. 0
   libavformat  53. 13. 0 / 53. 13. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 43. 5 /  2. 43. 5
   libswscale    2.  1. 0 /  2.  1. 0
 [mp3 @ 0x12cb7a0] Header missing

 Seems stream 0 codec frame rate differs from container frame rate: 23.98
 (65535/2733) -> 23.98 (2500000/104271)
 Input #0, avi, from 'avdesync.avi':
   Metadata:
     encoder         : VirtualDubMod 1.5.10.2 (build 2540/release)
   Duration: 01:54:18.98, start: 0.000000, bitrate: 69 kb/s
     Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID /
 0x44495658), yuv420p, 720x304 [SAR 1:1 DAR 45:19], 23.98 fps, 23.98 tbr,
 23.98 tbn, 23.98 tbc
     Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16,
 128 kb/s
 [buffer @ 0x12eb0c0] w:720 h:304 pixfmt:yuv420p tb:1/1000000 sar:1/1
 sws_param:
 Incompatible sample format 's16' for codec 'ac3', auto-selecting format
 'flt'
 Output #0, avi, to 'out.avi':
   Metadata:
     ISFT            : Lavf53.13.0
     Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 720x304 [SAR
 1:1 DAR 45:19], q=2-31, 200 kb/s, 23.98 tbn, 23.98 tbc
     Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, flt,
 128 kb/s
 Stream mapping:
   Stream #0.0 -> #0.0 (mpeg4 -> mpeg4)
   Stream #0.1 -> #0.1 (mp3 -> ac3)
 Press [q] to stop, [?] for help
 [mp3 @ 0x12cb7a0] Header missing
 Error while decoding stream #0.1
 frame= 3475 fps=302 q=2.0 Lsize=   66122kB time=00:02:24.00
 bitrate=3761.6kbits/s
 video:63673kB audio:2250kB global headers:0kB muxing overhead 0.300935%
 }}}

 out2.avi shows ~0.7 seconds desync:
 {{{
 $ ffmpeg -i avdesync.avi -vcodec copy -acodec copy -r 24000/1001 -t 145
 out2.avi
 ffmpeg version N-32916-g73a5287, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Sep 25 2011 12:04:12 with gcc 4.5.3
   configuration: --enable-libvpx --enable-libvorbis
 --cc=/usr/local/gcc-4.5.3/bin/gcc
   libavutil    51. 17. 0 / 51. 17. 0
   libavcodec   53. 17. 0 / 53. 17. 0
   libavformat  53. 13. 0 / 53. 13. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 43. 5 /  2. 43. 5
   libswscale    2.  1. 0 /  2.  1. 0
 [mp3 @ 0x12cb7a0] Header missing

 Seems stream 0 codec frame rate differs from container frame rate: 23.98
 (65535/2733) -> 23.98 (2500000/104271)
 Input #0, avi, from 'avdesync.avi':
   Metadata:
     encoder         : VirtualDubMod 1.5.10.2 (build 2540/release)
   Duration: 01:54:18.98, start: 0.000000, bitrate: 69 kb/s
     Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID /
 0x44495658), yuv420p, 720x304 [SAR 1:1 DAR 45:19], 23.98 fps, 23.98 tbr,
 23.98 tbn, 23.98 tbc
     Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16,
 128 kb/s
 Output #0, avi, to 'out2.avi':
   Metadata:
     ISFT            : Lavf53.13.0
     Stream #0:0: Video: mpeg4 (XVID / 0x44495658), yuv420p, 720x304 [SAR
 1:1 DAR 45:19], q=2-31, 23.98 tbn, 23.98 tbc
     Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, 128
 kb/s
 Stream mapping:
   Stream #0.0 -> #0.0 (copy)
   Stream #0.1 -> #0.1 (copy)
 Press [q] to stop, [?] for help
 frame= 3477 fps=  0 q=-1.0 Lsize=   58404kB time=00:02:25.00
 bitrate=3299.4kbits/s
 video:55905kB audio:2266kB global headers:0kB muxing overhead 0.401601%
 }}}

 I will upload the beginning of the sample: Audio gets significantly
 quieter too early.

-- 
Ticket URL: <https://avcodec.org/trac/ffmpeg/ticket/507>
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