[FFmpeg-trac] #3918(avcodec:open): Bitrate incorrectly detected when decoding mp2 (was: MP2 audio encoder increases stream duration)

[FFmpeg]

#3918: Bitrate incorrectly detected when decoding mp2
-------------------------------------+-------------------------------------
             Reporter:  abc123       |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  important    |                Component:  avcodec
              Version:  git-master   |               Resolution:
             Keywords:  mp2          |               Blocked By:
  regression                         |  Reproduced by developer:  1
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Changes (by cehoyos):

 * status:  new => open
 * reproduced:  0 => 1
 * priority:  normal => important
 * version:  2.3 => git-master
 * keywords:   => mp2 regression


Comment:

 Regression since c33351f3
 {{{
 $ ffmpeg -f lavfi -i sine -t 3600 out.mp2
 }}}
 {{{
 $ ffmpeg -i out.mp2 -f null -
 ffmpeg version N-66066-g928cb84 Copyright (c) 2000-2014 the FFmpeg
 developers
   built on Sep  3 2014 09:31:54 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl
   libavutil      54.  7.100 / 54.  7.100
   libavcodec     56.  1.100 / 56.  1.100
   libavformat    56.  3.100 / 56.  3.100
   libavdevice    56.  0.100 / 56.  0.100
   libavfilter     5.  0.103 /  5.  0.103
   libswscale      3.  0.100 /  3.  0.100
   libswresample   1.  1.100 /  1.  1.100
   libpostproc    53.  0.100 / 53.  0.100
 [mp3 @ 0x2aa3d40] Estimating duration from bitrate, this may be inaccurate
 Input #0, mp3, from 'out.mp2':
   Duration: 01:01:12.14, start: 0.000000, bitrate: 376 kb/s
     Stream #0:0: Audio: mp2, 44100 Hz, mono, s16p, 376 kb/s
 Output #0, null, to 'pipe:':
   Metadata:
     encoder         : Lavf56.3.100
     Stream #0:0: Audio: pcm_s16le, 44100 Hz, mono, s16, 705 kb/s
     Metadata:
       encoder         : Lavc56.1.100 pcm_s16le
 Stream mapping:
   Stream #0:0 -> #0:0 (mp2 (native) -> pcm_s16le (native))
 Press [q] to stop, [?] for help
 size=N/A time=01:00:00.01 bitrate=N/A
 video:0kB audio:310079kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: unknown
 }}}
 Actual bitrate is 384kb/s.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/3918#comment:3>
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