[FFmpeg-trac] #3201(undetermined:new): A/V desync without -async 1

[FFmpeg]

#3201: A/V desync without -async 1
-------------------------------------+-------------------------------------
               Reporter:  cehoyos    |                  Owner:
                   Type:  defect     |                 Status:  new
               Priority:  normal     |              Component:
                Version:  git-       |  undetermined
  master                             |               Keywords:
             Blocked By:             |               Blocking:
Reproduced by developer:  0          |  Analyzed by developer:  0
-------------------------------------+-------------------------------------
 I "fixed" the sample from ticket #3195 with a hex editor to allow testing
 with MPlayer and older FFmpeg versions.
 The sample plays fine (no A/V desync) with at least FFplay, MPlayer and
 vlc, transcoding with FFmpeg leads to a file with severe desync if
 {{{-async 1}}} was not used.
 out.avi shows A/V desync:
 {{{
 $ ffmpeg -i detect_aac.mpg -qscale 2 out.avi
 ffmpeg version N-58799-g5ac5581 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Dec  6 2013 10:16:53 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl
   libavutil      52. 56.100 / 52. 56.100
   libavcodec     55. 45.100 / 55. 45.100
   libavformat    55. 22.100 / 55. 22.100
   libavdevice    55.  5.102 / 55.  5.102
   libavfilter     3. 91.100 /  3. 91.100
   libswscale      2.  5.101 /  2.  5.101
   libswresample   0. 17.104 /  0. 17.104
   libpostproc    52.  3.100 / 52.  3.100
 [aac @ 0x19127a0] get_buffer() failed
 Input #0, mpeg, from 'detect_aac.mpg':
   Duration: 00:00:31.10, start: 0.000000, bitrate: 19585 kb/s
     Stream #0:0[0x1e0]: Video: h264 (Main), yuv420p(tv), 1920x1080 [SAR
 1:1 DAR 16:9], 30 fps, 30 tbr, 90k tbn, 60 tbc
     Stream #0:1[0x1c0]: Audio: aac, 44100 Hz, stereo, fltp, 134 kb/s
 Please use -q:a or -q:v, -qscale is ambiguous
 Output #0, avi, to 'out.avi':
   Metadata:
     ISFT            : Lavf55.22.100
     Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 1920x1080 [SAR
 1:1 DAR 16:9], q=2-31, 200 kb/s, 30 tbn, 30 tbc
     Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 44100 Hz, stereo, fltp,
 192 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (h264 -> mpeg4)
   Stream #0:1 -> #0:1 (aac -> ac3)
 Press [q] to stop, [?] for help
 [aac @ 0x19127a0] Input buffer exhausted before END element found
 Error while decoding stream #0:1: Invalid data found when processing input
 frame=  903 fps=160 q=2.0 Lsize=  103095kB time=00:00:31.13
 bitrate=27126.9kbits/s
 video:102338kB audio:704kB subtitle:0 global headers:0kB muxing overhead
 0.051418%
 }}}
 Works fine with {{{-async 1}}}
 {{{
 $ ffmpeg -i detect_aac.mpg -async 1 -qscale 2 outasync.avi
 ffmpeg version N-58799-g5ac5581 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Dec  6 2013 10:16:53 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl
   libavutil      52. 56.100 / 52. 56.100
   libavcodec     55. 45.100 / 55. 45.100
   libavformat    55. 22.100 / 55. 22.100
   libavdevice    55.  5.102 / 55.  5.102
   libavfilter     3. 91.100 /  3. 91.100
   libswscale      2.  5.101 /  2.  5.101
   libswresample   0. 17.104 /  0. 17.104
   libpostproc    52.  3.100 / 52.  3.100
 [aac @ 0x21067a0] get_buffer() failed
 Input #0, mpeg, from 'detect_aac.mpg':
   Duration: 00:00:31.10, start: 0.000000, bitrate: 19585 kb/s
     Stream #0:0[0x1e0]: Video: h264 (Main), yuv420p(tv), 1920x1080 [SAR
 1:1 DAR 16:9], 30 fps, 30 tbr, 90k tbn, 60 tbc
     Stream #0:1[0x1c0]: Audio: aac, 44100 Hz, stereo, fltp, 134 kb/s
 Please use -q:a or -q:v, -qscale is ambiguous
 -async is forwarded to lavfi similarly to -af
 aresample=async=1:min_hard_comp=0.100000:first_pts=0.
 Output #0, avi, to 'outasync.avi':
   Metadata:
     ISFT            : Lavf55.22.100
     Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 1920x1080 [SAR
 1:1 DAR 16:9], q=2-31, 200 kb/s, 30 tbn, 30 tbc
     Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 44100 Hz, stereo, fltp,
 192 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (h264 -> mpeg4)
   Stream #0:1 -> #0:1 (aac -> ac3)
 Press [q] to stop, [?] for help
 [aac @ 0x21067a0] Input buffer exhausted before END element found
 Error while decoding stream #0:1: Invalid data found when processing input
 frame=  903 fps=161 q=2.0 Lsize=  103119kB time=00:00:31.13
 bitrate=27133.4kbits/s
 video:102338kB audio:728kB subtitle:0 global headers:0kB muxing overhead
 0.051406%
 }}}

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Ticket URL: <https://trac.ffmpeg.org/ticket/3201>
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