[FFmpeg-trac] #110(avformat:open): MP4 Muxer gives incorrect frame duration with AAC

[FFmpeg]

#110: MP4 Muxer gives incorrect frame duration with AAC
------------------------------------+------------------------------------
             Reporter:  thebombzen  |                    Owner:
                 Type:  defect      |                   Status:  open
             Priority:  normal      |                Component:  avformat
              Version:  git-master  |               Resolution:
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
------------------------------------+------------------------------------
Changes (by cehoyos):

 * version:  git => git-master


Comment:

 {{{
 $ ffmpeg -i ticket110.mp4 -acodec copy out.m4a
 ffmpeg version N-33430-gcb50ada, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Oct  9 2011 20:28:29 with gcc 4.5.3
   configuration: --cc=/usr/local/gcc-4.5.3/bin/gcc
   libavutil    51. 20. 1 / 51. 20. 1
   libavcodec   53. 19. 1 / 53. 19. 1
   libavformat  53. 14. 0 / 53. 14. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 43. 6 /  2. 43. 6
   libswscale    2.  1. 0 /  2.  1. 0
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'ticket110.mp4':
   Metadata:
     major_brand     : isom
     minor_version   : 512
     compatible_brands: isomiso2mp41
     creation_time   : 1969-12-31 23:00:00
     encoder         : Lavf53.14.0
   Duration: 00:00:50.50, start: 0.000000, bitrate: 104 kb/s
     Stream #0:0(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo,
 s16, 99 kb/s
     Metadata:
       creation_time   : 1969-12-31 23:00:00
 Output #0, ipod, to 'out.m4a':
   Metadata:
     major_brand     : isom
     minor_version   : 512
     compatible_brands: isomiso2mp41
     creation_time   : 1969-12-31 23:00:00
     encoder         : Lavf53.14.0
     Stream #0:0(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, 99
 kb/s
     Metadata:
       creation_time   : 1969-12-31 23:00:00
 Stream mapping:
   Stream #0.0 -> #0.0 (copy)
 Press [q] to stop, [?] for help
 size=     647kB time=00:00:50.50 bitrate= 104.9kbits/s
 video:0kB audio:616kB global headers:0kB muxing overhead 5.001625%
 }}}
 {{{
 $ ffmpeg -i out.m4a
 ffmpeg version N-33430-gcb50ada, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Oct  9 2011 20:28:29 with gcc 4.5.3
   configuration: --cc=/usr/local/gcc-4.5.3/bin/gcc
   libavutil    51. 20. 1 / 51. 20. 1
   libavcodec   53. 19. 1 / 53. 19. 1
   libavformat  53. 14. 0 / 53. 14. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 43. 6 /  2. 43. 6
   libswscale    2.  1. 0 /  2.  1. 0
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'out.m4a':
   Metadata:
     major_brand     : M4A
     minor_version   : 512
     compatible_brands: isomiso2
     creation_time   : 1969-12-30 23:00:00
     encoder         : Lavf53.14.0
   Duration: 00:00:50.50, start: 0.000000, bitrate: 104 kb/s
     Stream #0:0(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo,
 s16, 99 kb/s
     Metadata:
       creation_time   : 1969-12-30 23:00:00
 At least one output file must be specified
 }}}
 {{{
 $ faad out.m4a
  *********** Ahead Software MPEG-4 AAC Decoder V2.7 ******************

  Build: Mar 31 2010
  Copyright 2002-2004: Ahead Software AG
  http://www.audiocoding.com
  Floating point version

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License.

 **************************************************************************

 out.m4a file info:

 LC AAC  50.454 secs, 2 ch, 44100 Hz

 tool: Lavf53.14.0

   ---------------------
  | Config:  2 Ch       |
   ---------------------
  | Ch |    Position    |
   ---------------------
  | 00 | Left front     |
  | 01 | Right front    |
   ---------------------

 MP4 seems to have incorrect frame duration, using values from AAC data.
 Decoding out.m4a took:  0.17 sec. 296.79x real-time.
 }}}

-- 
Ticket URL: <https://avcodec.org/trac/ffmpeg/ticket/110#comment:4>
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