[FFmpeg-trac] #2590(avformat:open): Inaccurate seek in mp3

[FFmpeg]

#2590: Inaccurate seek in mp3
-------------------------------------+-------------------------------------
             Reporter:  eleventeen   |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  important    |                Component:  avformat
              Version:  git-master   |               Resolution:
             Keywords:  mp3          |               Blocked By:
  regression                         |  Reproduced by developer:  1
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Changes (by cehoyos):

 * keywords:   => mp3 regression
 * priority:  normal => important
 * status:  new => open
 * reproduced:  0 => 1


Comment:

 Regression since 5864ce1 / 50d1f44
 out.wav starts at ~25sec and is too long.
 {{{
 $ ffmpeg -ss 50 -i Underworld_sample_cut.mp3 -t 10 out.wav
 ffmpeg version N-53274-g73b9f31 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on May 19 2013 19:14:12 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl --disable-indev=jack
   libavutil      52. 33.100 / 52. 33.100
   libavcodec     55. 10.101 / 55. 10.101
   libavformat    55.  7.100 / 55.  7.100
   libavdevice    55.  0.100 / 55.  0.100
   libavfilter     3. 68.101 /  3. 68.101
   libswscale      2.  3.100 /  2.  3.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  3.100 / 52.  3.100
 [mp3 @ 0x3106840] max_analyze_duration 5000000 reached at 5015510
 microseconds
 Input #0, mp3, from 'Underworld_sample_cut.mp3':
   Metadata:
     artist          : Lilith
     album           : Underworld
     genre           : Gothic Metal
     date            : 2007
   Duration: 00:42:36.63, start: 0.000000, bitrate: 4 kb/s
     Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p, 192 kb/s
 Output #0, wav, to 'out.wav':
   Metadata:
     IART            : Lilith
     IPRD            : Underworld
     IGNR            : Gothic Metal
     ICRD            : 2007
     ISFT            : Lavf55.7.100
     Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz,
 stereo, s16, 1411 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (mp3 -> pcm_s16le)
 Press [q] to stop, [?] for help
 size=    5936kB time=00:00:10.02 bitrate=4851.9kbits/s
 video:0kB audio:5936kB subtitle:0 global headers:0kB muxing overhead
 0.002501%
 }}}
 {{{
 $ ffmpeg -i out.wav -f null -
 ffmpeg version N-53274-g73b9f31 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on May 19 2013 19:14:12 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl --disable-indev=jack
   libavutil      52. 33.100 / 52. 33.100
   libavcodec     55. 10.101 / 55. 10.101
   libavformat    55.  7.100 / 55.  7.100
   libavdevice    55.  0.100 / 55.  0.100
   libavfilter     3. 68.101 /  3. 68.101
   libswscale      2.  3.100 /  2.  3.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  3.100 / 52.  3.100
 [wav @ 0x34bf840] max_analyze_duration 5000000 reached at 5015510
 microseconds
 Guessed Channel Layout for  Input Stream #0.0 : stereo
 Input #0, wav, from 'out.wav':
   Metadata:
     artist          : Lilith
     date            : 2007
     genre           : Gothic Metal
     album           : Underworld
     encoder         : Lavf55.7.100
   Duration: 00:00:34.46, bitrate: 1411 kb/s
     Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz,
 stereo, s16, 1411 kb/s
 Output #0, null, to 'pipe:':
   Metadata:
     artist          : Lilith
     date            : 2007
     genre           : Gothic Metal
     album           : Underworld
     encoder         : Lavf55.7.100
     Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (pcm_s16le -> pcm_s16le)
 Press [q] to stop, [?] for help
 size=N/A time=00:00:34.45 bitrate=N/A
 video:0kB audio:5936kB subtitle:0 global headers:0kB muxing overhead
 -100.000362%
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2590#comment:6>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker