[FFmpeg-user] Divide one Four-Channel Stream into Two Stereo Streams

[Karl E. Fitzke]

Finally getting back to a task I got called away from months ago...


Trying to divide Stream of 4 channel audio in a video to 2 stereo streams.


Does anyone see what might be going wrong here?  I instead get one stereo stream and one four channel stream.  I'd bring ffmpeg up to the latest version, but I want to finish one job before I do that if I can.


lib-6043-1:FourChannelTest dmgvideoadmin$ ffmpeg -i ShortFourChanCaygill.mov -c:v copy -c:a pcm_s16le -map 0:0 -map 0:1 -filter:a:0 "pan=stereo|c0=c0|c1=c1" -map 0:1 -filter:a:0 "pan=stereo|c0=c2|c1=c3" TwoStereo.mov
ffmpeg version 2.6.3 Copyright (c) 2000-2015 the FFmpeg developers
  built with Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.6.3 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-vda
  libavutil      54. 20.100 / 54. 20.100
  libavcodec     56. 26.100 / 56. 26.100
  libavformat    56. 25.101 / 56. 25.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 11.102 /  5. 11.102
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'ShortFourChanCaygill.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    encoder         : Lavf56.25.101
  Duration: 00:00:30.03, start: 0.000000, bitrate: 226800 kb/s
    Stream #0:0(eng): Video: v210 (v210 / 0x30313276), yuv422p10le, 720x486, 223725 kb/s, SAR 9:10 DAR 4:3, 29.97 fps, 29.97 tbr, 30k tbn, 30k tbc (default)
    Metadata:
      handler_name    : DataHandler
      encoder         : Uncompressed 10-Bit YUV
      timecode        : 00:00:00;00
    Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, 4.0, s16, 3072 kb/s (default)
    Metadata:
      handler_name    : DataHandler
    Stream #0:2(eng): Data: none (tmcd / 0x64636D74), 0 kb/s
    Metadata:
      handler_name    : DataHandler
      timecode        : 00:00:00;00
[Parsed_pan_0 @ 0x7ff142d01a80] Pure channel mapping detected: 2 3
Output #0, mov, to 'TwoStereo.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    encoder         : Lavf56.25.101
    Stream #0:0(eng): Video: v210 (v210 / 0x30313276), yuv422p10le, 720x486 [SAR 9:10 DAR 4:3], q=2-31, 223725 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 30k tbc (default)
    Metadata:
      handler_name    : DataHandler
      encoder         : Uncompressed 10-Bit YUV
      timecode        : 00:00:00;00
    Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, stereo, s16, 1536 kb/s (default)
    Metadata:
      handler_name    : DataHandler
      encoder         : Lavc56.26.100 pcm_s16le
    Stream #0:2(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, 4.0, s16, 3072 kb/s (default)
    Metadata:
      handler_name    : DataHandler
      encoder         : Lavc56.26.100 pcm_s16le
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (pcm_s16le (native) -> pcm_s16le (native))
  Stream #0:1 -> #0:2 (pcm_s16le (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
frame=  900 fps=805 q=-1.0 Lsize=  837028kB time=00:00:30.01 bitrate=228427.7kbits/s
video:820125kB audio:16885kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.002192%


Karl Fitzke
Audio/Visual Specialist
B76 Kroch Library
Ithaca, NY 14853

607-255-5521
karl.fitzke at cornell.edu