[FFmpeg-user] Error initializing filter 'channelsplit' with args 'channel_layout=stereo:channels=FL|FR'

[adam smith]

Hi Everyone,

I have been running this command no problem using FFmpeg 5.0;  but after updating to 5.1.2 it is complaining about the arguments used in the channel split.
Error initializing filter 'channelsplit' with args 'channel_layout=stereo:channels=FL|FR’


Command line
ffmpeg -i /data/disposable/419255_20230104-7-gnim60/5d5c058e-e2ca-4a7d-8622-0a529322bfb3_1672828076604.mp4 -filter_complex "[0:0]minterpolate=mi_mode=dup:fps=29.97[0frame_conversion];[0:1]channelsplit=channel_layout=stereo:channels=FL|FR[001_channelsplit][002_channelsplit];[001_channelsplit]asplit=8[001_asplit][003_asplit][005_asplit][007_asplit][009_asplit][011_asplit][013_asplit][015_asplit];[002_channelsplit]asplit=8[002_asplit][004_asplit][006_asplit][008_asplit][010_asplit][012_asplit][014_asplit][016_asplit]"  -map "[0frame_conversion]" -map "[001_asplit]" -map "[002_asplit]" -map "[003_asplit]" -map "[004_asplit]" -map "[005_asplit]" -map "[006_asplit]" -map "[007_asplit]" -map "[008_asplit]" -map "[009_asplit]" -map "[010_asplit]" -map "[011_asplit]" -map "[012_asplit]" -map "[013_asplit]" -map "[014_asplit]" -map "[015_asplit]" -map "[016_asplit]" -c:v dnxhd -pix_fmt yuv422p -s 1920x1080 -b:v 145M -flags +ildct+ilme -r 30000/1001 -c:a pcm_s24le -ar 48000 -f tee "/data/disposable/419255_20230104-7-gnim60/5d5c058e-e2ca-4a7d-8622-0a529322bfb3_1672828076604.mxf”

Output
ffmpeg version 5.1.1 Copyright (c) 2000-2022 the FFmpeg developers
  built with gcc 12.2.1 (Alpine 12.2.1_git20220924-r4) 20220924
  configuration: --prefix=/opt/ffmpeg --disable-debug --disable-doc --disable-ffplay --enable-shared --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-gpl --enable-libass --enable-fontconfig --enable-libfreetype --enable-libfontconfig --enable-libfribidi --enable-libvidstab --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libxcb --enable-libx265 --enable-libxvid --enable-libx264 --enable-nonfree --enable-openssl --enable-libfdk_aac --enable-postproc --enable-small --enable-version3 --enable-libbluray --disable-libzmq --enable-libopenjpeg --enable-libkvazaar --enable-libaom --enable-libsrt --enable-libaribb24 --extra-libs=-ldl --extra-libs=-lpthread --extra-cflags=-I/opt/ffmpeg/include --extra-ldflags=-L/opt/ffmpeg/lib
  libavutil      57. 28.100 / 57. 28.100
  libavcodec     59. 37.100 / 59. 37.100
  libavformat    59. 27.100 / 59. 27.100
  libavdevice    59.  7.100 / 59.  7.100
  libavfilter     8. 44.100 /  8. 44.100
  libswscale      6.  7.100 /  6.  7.100
  libswresample   4.  7.100 /  4.  7.100
  libpostproc    56.  6.100 / 56.  6.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/data/disposable/419255_20230104-7-gnim60/5d5c058e-e2ca-4a7d-8622-0a529322bfb3_1672828076604.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
  Duration: 00:00:58.21, start: 0.000000, bitrate: 15153 kb/s
  Stream #0:0[0x1](und): Video: h264 (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], 14957 kb/s, 25 fps, 25 tbr, 12800 tbn (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 192 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]
  Stream #0:2[0x3](und): Subtitle: mov_text (tx3g / 0x67337874), 1920x1080, 0 kb/s (default)
    Metadata:
      handler_name    : SubtitleHandler
[AVFilterGraph @ 0x7f673f65e180] Error initializing filter 'channelsplit' with args 'channel_layout=stereo:channels=FL|FR'
Error initializing complex filters.
Invalid argument


I realise that in this example the channel layout is not really required as it would default to ‘all’ which for this would be fine, but sometimes the source will be 5.1 and I only need FL & FR so I try and keep the command consistent.

Do you know if the syntax has changed between versions?

Thanks for your help as always
Adam