[FFmpeg-trac] #6(avformat:new): Alsa output channel order is wrong

FFmpeg trac at avcodec.org
Sat Mar 12 00:43:36 CET 2011

#6: Alsa output channel order is wrong
  Reporter:  cehoyos  |      Owner:  michael
      Type:  defect   |     Status:  new
  Priority:  normal   |  Component:  avformat
   Version:  git      |   Keywords:
Blocked By:           |   Blocking:
Reproduced:  1        |   Analyzed:  1
 When using ffmpeg -i input -f alsa, the channel order is typically wrong
 for >2 channels.
 Alsa expects 5.1 in the order: front left - front right - surround left -
 surround right - centre - lfe, FFmpeg's internal channel order is front
 left - front right - centre - lfe - surround left - surround right (for
 7.1, back channels are last in both cases).

 The order is correct for AV_CH_LAYOUT_QUAD, for AV_CH_LAYOUT_4POINT0
 (Edward.Scissorhands.x264.DTS-4.0-48_24.mkv), it would be necessary to
 expand output to (at least) five channels.

Ticket URL: <http://avcodec.org/trac/ffmpeg/ticket/6>
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