[FFmpeg-trac] #2283(undetermined:new): Slow counter / incorrect duration for aac-in-flv

FFmpeg trac at avcodec.org
Tue Feb 19 10:26:26 CET 2013


#2283: Slow counter / incorrect duration for aac-in-flv
-------------------------------------+-------------------------------------
               Reporter:  cehoyos    |                  Owner:
                   Type:  defect     |                 Status:  new
               Priority:  normal     |              Component:
                Version:  git-       |  undetermined
  master                             |               Keywords:  videolan
             Blocked By:             |  flv aac
Reproduced by developer:  0          |               Blocking:
                                     |  Analyzed by developer:  0
-------------------------------------+-------------------------------------
 (videolan ticket 8195)
 I will upload an audio-only flv sample that can be decoded but the shown
 duration is wrong, both the duration shown before decoding and the
 duration shown after decoding.
 The time counter is wrong for both ffplay and MPlayer, seeking works fine
 with MPlayer, fails with ffplay.
 {{{
 $ ffmpeg -i sky_the80s_aacplus.flv out.wav
 ffmpeg version N-50086-gd41efc1 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Feb 19 2013 09:36:55 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl --disable-indev=jack
   libavutil      52. 17.102 / 52. 17.102
   libavcodec     54. 92.100 / 54. 92.100
   libavformat    54. 63.100 / 54. 63.100
   libavdevice    54.  3.103 / 54.  3.103
   libavfilter     3. 38.103 /  3. 38.103
   libswscale      2.  2.100 /  2.  2.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  2.100 / 52.  2.100
 [flv @ 0x32bdfc0] max_analyze_duration 5000000 reached at 5014000
 microseconds
 Input #0, flv, from 'sky_the80s_aacplus.flv':
   Duration: 00:01:08.77, start: 0.000000, bitrate: 74 kb/s
     Stream #0:0: Audio: aac, 44100 Hz, stereo, fltp
 Output #0, wav, to 'out.wav':
   Metadata:
     ISFT            : Lavf54.63.100
     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 (aac -> pcm_s16le)
 Press [q] to stop, [?] for help
 [flv @ 0x32bdfc0] Stream discovered after head already parsed
 [flv @ 0x32bdfc0] New data stream 0:1 at pos:254270 and DTS:27.274s
 size=   21168kB time=00:01:08.81 bitrate=2519.9kbits/s
 video:0kB audio:21168kB subtitle:0 global headers:0kB muxing overhead
 0.000369%
 }}}
 Duration and time claim that the sample is ~68 seconds, but it actually is
 over two minutes long:
 {{{
 $ ffmpeg -i out.wav -f null -
 ffmpeg version N-50086-gd41efc1 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Feb 19 2013 09:36:55 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl --disable-indev=jack
   libavutil      52. 17.102 / 52. 17.102
   libavcodec     54. 92.100 / 54. 92.100
   libavformat    54. 63.100 / 54. 63.100
   libavdevice    54.  3.103 / 54.  3.103
   libavfilter     3. 38.103 /  3. 38.103
   libswscale      2.  2.100 /  2.  2.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  2.100 / 52.  2.100
 [wav @ 0x1c49fc0] max_analyze_duration 5000000 reached at 5015510
 microseconds
 Guessed Channel Layout for  Input Stream #0.0 : stereo
 Input #0, wav, from 'out.wav':
   Metadata:
     encoder         : Lavf54.63.100
   Duration: 00:02:02.88, 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:
     encoder         : Lavf54.63.100
     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=00:02:02.88 bitrate=N/A
 video:0kB audio:21168kB subtitle:0 global headers:0kB muxing overhead
 -100.000101%
 }}}
 The same can be shown with ffplay:
 {{{
 $ time ffplay sky_the80s_aacplus.flv
 ffplay version N-50086-gd41efc1 Copyright (c) 2003-2013 the FFmpeg
 developers
   built on Feb 19 2013 09:36:55 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl --disable-indev=jack
   libavutil      52. 17.102 / 52. 17.102
   libavcodec     54. 92.100 / 54. 92.100
   libavformat    54. 63.100 / 54. 63.100
   libavdevice    54.  3.103 / 54.  3.103
   libavfilter     3. 38.103 /  3. 38.103
   libswscale      2.  2.100 /  2.  2.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  2.100 / 52.  2.100
 [flv @ 0x7f7d6c0008c0] max_analyze_duration 5000000 reached at 5014000
 microseconds
 Input #0, flv, from 'sky_the80s_aacplus.flv':
   Duration: 00:01:08.77, start: 0.000000, bitrate: 74 kb/s
     Stream #0:0: Audio: aac, 44100 Hz, stereo, fltp
   23.20 A-V:  0.000 fd=   0 aq=    1KB vq=    0KB sq=    0B f=0/0

 real    0m43.481s
 user    0m0.937s
 sys     0m0.474s
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2283>
FFmpeg <http://ffmpeg.org>
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