[FFmpeg-user] Need help splitting stereo FLAC into two separate files

Net Net dastiegen at gmail.com
Sun Apr 5 04:34:23 EEST 2020


I have stereo file "1.flac" which is actually two monaural recordings, one
in each channel. I want to separate these two channels into separate FLAC
files.  I'm trying to follow the channelsplit examples in the ffmpeg
filters manual sec. 8.53.1.  But I can't find a full list of this filter's
arguments, and can't get it to work by trial and error,  The input file
1.flac is in the same folder as ffmpeg.

Below is a dump of the some of the command window attempts I've made, with
the ffmpeg output results.

Can you please tell me a command line that will work for this?

Thanks, Dasty


-----------------------------------------------------------------------------------
Microsoft Windows [Version 10.0.18363.752]

C:\_Util\ffmpeg>ffmpeg.exe -i 1.flac -filter_complex
'channelsplit=channel_layout=2.0[FL][FR]' -map '[FL]' front_left.flac -map
'[FR]' front_right.flac

ffmpeg version git-2020-04-03-52523b6 Copyright (c) 2000-2020 the FFmpeg
developers
  built with gcc 9.3.1 (GCC) 20200328
  configuration: --enable-gpl --enable-version3 --enable-sdl2
--enable-fontconfig --enable-gnutls --enable-iconv --enable-libass
--enable-libdav1d --enable-libbluray --enable-libfreetype
--enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
--enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy
--enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame
--enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264
--enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma
--enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf
--enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa
--enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx
--enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va
--enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
--enable-libopenmpt --enable-amf
  libavutil      56. 42.102 / 56. 42.102
  libavcodec     58. 77.101 / 58. 77.101
  libavformat    58. 42.100 / 58. 42.100
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 77.101 /  7. 77.101
  libswscale      5.  6.101 /  5.  6.101
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, flac, from '1.flac':
  Metadata:
    AccurateRipResult: AccurateRip: Not in database   [D4EF7918]
    AccurateRipDiscID: 025-00347e29-03bea48e-5c0e1019-1
    Title           : Track 1
    Source          : CD (Lossless)
    Encoded By      : dBpoweramp Release 15.1
    Encoder         : (FLAC 1.3.0)
    Encoder Settings: -compression-level-8 -verify
    track           : 1
    TRACKTOTAL      : 25
    disc            : 1
    DISCTOTAL       : 1
  Duration: 00:00:15.19, start: 0.000000, bitrate: 433 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
[AVFilterGraph @ 000001d1ff964340] No such filter:
'channelsplit=channel_layout=2.0[FL][FR]'
Error initializing complex filters.
Invalid argument

C:\_Util\ffmpeg>ffmpeg.exe -i 1.flac -filter_complex
'channelsplit=channel_layout=2.[FL][FR]' -map '[FL]' front_left.flac -map
'[FR]' front_right.flac
ffmpeg version git-2020-04-03-52523b6 Copyright (c) 2000-2020 the FFmpeg
developers
  built with gcc 9.3.1 (GCC) 20200328
  configuration: --enable-gpl --enable-version3 --enable-sdl2
--enable-fontconfig --enable-gnutls --enable-iconv --enable-libass
--enable-libdav1d --enable-libbluray --enable-libfreetype
--enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
--enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy
--enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame
--enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264
--enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma
--enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf
--enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa
--enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx
--enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va
--enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
--enable-libopenmpt --enable-amf
  libavutil      56. 42.102 / 56. 42.102
  libavcodec     58. 77.101 / 58. 77.101
  libavformat    58. 42.100 / 58. 42.100
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 77.101 /  7. 77.101
  libswscale      5.  6.101 /  5.  6.101
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, flac, from '1.flac':
  Metadata:
    AccurateRipResult: AccurateRip: Not in database   [D4EF7918]
    AccurateRipDiscID: 025-00347e29-03bea48e-5c0e1019-1
    Title           : Track 1
    Source          : CD (Lossless)
    Encoded By      : dBpoweramp Release 15.1
    Encoder         : (FLAC 1.3.0)
    Encoder Settings: -compression-level-8 -verify
    track           : 1
    TRACKTOTAL      : 25
    disc            : 1
    DISCTOTAL       : 1
  Duration: 00:00:15.19, start: 0.000000, bitrate: 433 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
[AVFilterGraph @ 000002963fbe4340] No such filter:
'channelsplit=channel_layout=2.[FL][FR]'
Error initializing complex filters.
Invalid argument

C:\_Util\ffmpeg>ffmpeg.exe -i 1.flac -filter_complex
'channelsplit=channel_layout=[FL][FR]' -map '[FL]' front_left.flac -map
'[FR]' front_right.flac
ffmpeg version git-2020-04-03-52523b6 Copyright (c) 2000-2020 the FFmpeg
developers
  built with gcc 9.3.1 (GCC) 20200328
  configuration: --enable-gpl --enable-version3 --enable-sdl2
--enable-fontconfig --enable-gnutls --enable-iconv --enable-libass
--enable-libdav1d --enable-libbluray --enable-libfreetype
--enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
--enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy
--enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame
--enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264
--enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma
--enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf
--enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa
--enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx
--enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va
--enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
--enable-libopenmpt --enable-amf
  libavutil      56. 42.102 / 56. 42.102
  libavcodec     58. 77.101 / 58. 77.101
  libavformat    58. 42.100 / 58. 42.100
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 77.101 /  7. 77.101
  libswscale      5.  6.101 /  5.  6.101
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, flac, from '1.flac':
  Metadata:
    AccurateRipResult: AccurateRip: Not in database   [D4EF7918]
    AccurateRipDiscID: 025-00347e29-03bea48e-5c0e1019-1
    Title           : Track 1
    Source          : CD (Lossless)
    Encoded By      : dBpoweramp Release 15.1
    Encoder         : (FLAC 1.3.0)
    Encoder Settings: -compression-level-8 -verify
    track           : 1
    TRACKTOTAL      : 25
    disc            : 1
    DISCTOTAL       : 1
  Duration: 00:00:15.19, start: 0.000000, bitrate: 433 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
[AVFilterGraph @ 000001a429734300] No such filter:
'channelsplit=channel_layout=[FL][FR]'
Error initializing complex filters.
Invalid argument

C:\_Util\ffmpeg>ffmpeg.exe -i 1.flac -filter_complex
'channelsplit=channel_layout=STEREO[FL][FR]' -map '[FL]' front_left.flac
-map '[FR]' front_right.flac
ffmpeg version git-2020-04-03-52523b6 Copyright (c) 2000-2020 the FFmpeg
developers
  built with gcc 9.3.1 (GCC) 20200328
  configuration: --enable-gpl --enable-version3 --enable-sdl2
--enable-fontconfig --enable-gnutls --enable-iconv --enable-libass
--enable-libdav1d --enable-libbluray --enable-libfreetype
--enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
--enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy
--enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame
--enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264
--enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma
--enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf
--enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa
--enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx
--enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va
--enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
--enable-libopenmpt --enable-amf
  libavutil      56. 42.102 / 56. 42.102
  libavcodec     58. 77.101 / 58. 77.101
  libavformat    58. 42.100 / 58. 42.100
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 77.101 /  7. 77.101
  libswscale      5.  6.101 /  5.  6.101
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, flac, from '1.flac':
  Metadata:
    AccurateRipResult: AccurateRip: Not in database   [D4EF7918]
    AccurateRipDiscID: 025-00347e29-03bea48e-5c0e1019-1
    Title           : Track 1
    Source          : CD (Lossless)
    Encoded By      : dBpoweramp Release 15.1
    Encoder         : (FLAC 1.3.0)
    Encoder Settings: -compression-level-8 -verify
    track           : 1
    TRACKTOTAL      : 25
    disc            : 1
    DISCTOTAL       : 1
  Duration: 00:00:15.19, start: 0.000000, bitrate: 433 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
[AVFilterGraph @ 00000223590e4340] No such filter:
'channelsplit=channel_layout=STEREO[FL][FR]'
Error initializing complex filters.
Invalid argument

C:\_Util\ffmpeg>ffmpeg.exe -i 1.flac -filter_complex
'channelsplit=channel_layout=2[FL][FR]' -map '[FL]' front_left.flac -map
'[FR]' front_right.flac
ffmpeg version git-2020-04-03-52523b6 Copyright (c) 2000-2020 the FFmpeg
developers
  built with gcc 9.3.1 (GCC) 20200328
  configuration: --enable-gpl --enable-version3 --enable-sdl2
--enable-fontconfig --enable-gnutls --enable-iconv --enable-libass
--enable-libdav1d --enable-libbluray --enable-libfreetype
--enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
--enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy
--enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame
--enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264
--enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma
--enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf
--enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa
--enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx
--enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va
--enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
--enable-libopenmpt --enable-amf
  libavutil      56. 42.102 / 56. 42.102
  libavcodec     58. 77.101 / 58. 77.101
  libavformat    58. 42.100 / 58. 42.100
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 77.101 /  7. 77.101
  libswscale      5.  6.101 /  5.  6.101
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, flac, from '1.flac':
  Metadata:
    AccurateRipResult: AccurateRip: Not in database   [D4EF7918]
    AccurateRipDiscID: 025-00347e29-03bea48e-5c0e1019-1
    Title           : Track 1
    Source          : CD (Lossless)
    Encoded By      : dBpoweramp Release 15.1
    Encoder         : (FLAC 1.3.0)
    Encoder Settings: -compression-level-8 -verify
    track           : 1
    TRACKTOTAL      : 25
    disc            : 1
    DISCTOTAL       : 1
  Duration: 00:00:15.19, start: 0.000000, bitrate: 433 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
[AVFilterGraph @ 0000013b24264300] No such filter:
'channelsplit=channel_layout=2[FL][FR]'
Error initializing complex filters.
Invalid argument

C:\_Util\ffmpeg>ffmpeg.exe -i 1.flac -filter_complex
'channelsplit=channel_layout=2:channels=[FL][FR]' -map '[FL]'
front_left.flac -map '[FR]' front_right.flac
ffmpeg version git-2020-04-03-52523b6 Copyright (c) 2000-2020 the FFmpeg
developers
  built with gcc 9.3.1 (GCC) 20200328
  configuration: --enable-gpl --enable-version3 --enable-sdl2
--enable-fontconfig --enable-gnutls --enable-iconv --enable-libass
--enable-libdav1d --enable-libbluray --enable-libfreetype
--enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
--enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy
--enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame
--enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264
--enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma
--enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf
--enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa
--enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx
--enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va
--enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
--enable-libopenmpt --enable-amf
  libavutil      56. 42.102 / 56. 42.102
  libavcodec     58. 77.101 / 58. 77.101
  libavformat    58. 42.100 / 58. 42.100
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 77.101 /  7. 77.101
  libswscale      5.  6.101 /  5.  6.101
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, flac, from '1.flac':
  Metadata:
    AccurateRipResult: AccurateRip: Not in database   [D4EF7918]
    AccurateRipDiscID: 025-00347e29-03bea48e-5c0e1019-1
    Title           : Track 1
    Source          : CD (Lossless)
    Encoded By      : dBpoweramp Release 15.1
    Encoder         : (FLAC 1.3.0)
    Encoder Settings: -compression-level-8 -verify
    track           : 1
    TRACKTOTAL      : 25
    disc            : 1
    DISCTOTAL       : 1
  Duration: 00:00:15.19, start: 0.000000, bitrate: 433 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
[AVFilterGraph @ 000002794ff74380] No such filter:
'channelsplit=channel_layout=2:channels=[FL][FR]'
Error initializing complex filters.
Invalid argument

C:\_Util\ffmpeg>ffmpeg.exe -i 1.flac -filter_complex
'channelsplit=channel_layout=STEREO:channels=[FL][FR]' -map '[FL]'
front_left.flac -map '[FR]' front_right.flac
ffmpeg version git-2020-04-03-52523b6 Copyright (c) 2000-2020 the FFmpeg
developers
  built with gcc 9.3.1 (GCC) 20200328
  configuration: --enable-gpl --enable-version3 --enable-sdl2
--enable-fontconfig --enable-gnutls --enable-iconv --enable-libass
--enable-libdav1d --enable-libbluray --enable-libfreetype
--enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
--enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy
--enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame
--enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264
--enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma
--enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf
--enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa
--enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx
--enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va
--enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
--enable-libopenmpt --enable-amf
  libavutil      56. 42.102 / 56. 42.102
  libavcodec     58. 77.101 / 58. 77.101
  libavformat    58. 42.100 / 58. 42.100
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 77.101 /  7. 77.101
  libswscale      5.  6.101 /  5.  6.101
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, flac, from '1.flac':
  Metadata:
    AccurateRipResult: AccurateRip: Not in database   [D4EF7918]
    AccurateRipDiscID: 025-00347e29-03bea48e-5c0e1019-1
    Title           : Track 1
    Source          : CD (Lossless)
    Encoded By      : dBpoweramp Release 15.1
    Encoder         : (FLAC 1.3.0)
    Encoder Settings: -compression-level-8 -verify
    track           : 1
    TRACKTOTAL      : 25
    disc            : 1
    DISCTOTAL       : 1
  Duration: 00:00:15.19, start: 0.000000, bitrate: 433 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
[AVFilterGraph @ 0000022ec3104380] No such filter:
'channelsplit=channel_layout=STEREO:channels=[FL][FR]'
Error initializing complex filters.
Invalid argument

C:\_Util\ffmpeg>


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