[FFmpeg-trac] #1088(swresample:new): Arbitrary dropping channels is not supported

[FFmpeg]

#1088: Arbitrary dropping channels is not supported
-------------------------------------+-------------------------------------
               Reporter:  cehoyos    |                  Owner:  michael
                   Type:             |                 Status:  new
  enhancement                        |              Component:  swresample
               Priority:  wish       |               Keywords:
                Version:  git-       |               Blocking:
  master                             |  Analyzed by developer:  0
             Blocked By:             |
Reproduced by developer:  0          |
-------------------------------------+-------------------------------------
 http://thread.gmane.org/gmane.comp.video.ffmpeg.user/36098

 If input has more than 8 channels, reducing the number of channels is not
 possible.
 {{{
 $ ffmpeg -f s16le -ac 16 -i /dev/zero -y -ac 2 -t 10 out.wav
 ffmpeg version N-38840-g32a5775 Copyright (c) 2000-2012 the FFmpeg
 developers
   built on Mar 17 2012 09:29:33 with gcc 4.3.2
   configuration: --cc=/usr/local/gcc-4.3.2/bin/gcc --enable-gpl
   libavutil      51. 42.100 / 51. 42.100
   libavcodec     54. 10.100 / 54. 10.100
   libavformat    54.  2.100 / 54.  2.100
   libavdevice    53.  4.100 / 53.  4.100
   libavfilter     2. 64.101 /  2. 64.101
   libswscale      2.  1.100 /  2.  1.100
   libswresample   0.  7.100 /  0.  7.100
   libpostproc    52.  0.100 / 52.  0.100
 [s16le @ 0x8eb8b40] Invalid sample rate 0 specified using default of 44100
 [s16le @ 0x8eb8b40] Estimating duration from bitrate, this may be
 inaccurate
 Input #0, s16le, from '/dev/zero':
   Duration: N/A, start: 0.000000, bitrate: 11289 kb/s
     Stream #0:0: Audio: pcm_s16le, 44100 Hz, 16 channels, s16, 11289 kb/s
 Output #0, wav, to 'out.wav':
   Metadata:
     encoder         : Lavf54.2.100
     Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, 2
 channels, s16, 1411 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (pcm_s16le -> pcm_s16le)
 Press [q] to stop, [?] for help
 [SWR @ 0x8eb4880] Input channel layout isnt supported
 swr_init() failed
 Can not resample 16 channels @ 44100 Hz to 2 channels @ 44100 Hz
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1088>
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