[Selur]

When I call:

ffmpeg -y -threads 8 -loglevel fatal -i "H:\Output\test.ac3" -ac 6 -ar 48000 -acodec pcm_s16le -f wav h:\Output\test.wav"

the channel order inside the test.wav file is okay, when I call:

ffmpeg -y -threads 8 -loglevel fatal -i "H:\Output\test.ac3" -ac 6 -ar 48000 -acodec pcm_s16le -f wav - > h:\Output\pipe.wav"

the channel order inside the pipe.wav file is okay, when I call:

ffmpeg -y -threads 8 -loglevel fatal -i "H:\Output\test.ac3" -ac 6 -ar 48000 -acodec pcm_s32le -f wav - | sox --multi-threaded --ignore-length --temp "H:\Temp" --buffer 524288 -S -t wav - -b 16 -t wav h:\Output\sox.wav

the channel order inside the sox.wav file is okay, when I call:

opusenc --bitrate 192 --comp 10 --framesize 20 --expect-loss 0 --max-delay 1000 h:\Output\sox.wav "H:\Output\test.opus"

the channel order of the test.opus file is okay, when I call:

ffmpeg -y -threads 8 -loglevel fatal -i "H:\Output\test.ac3" -ac 6 -ar 48000 -f sox - | sox --multi-threaded --ignore-length --temp "H:\Temp" --buffer 524288 -S -t sox - -t wav h:\Output\sox2.wav

the channel order of the sox2.wav file is okay, when I call:

ffmpeg -y -threads 8 -loglevel fatal -i "H:\Output\test.ac3" -ac 6 -ar 48000 -f sox - | sox --multi-threaded --ignore-length --temp "H:\Temp" --buffer 524288 -S -t sox - -t wav -b 16 - | opusenc --bitrate 192 --comp 10 --framesize 20 --expect-loss 0 --max-delay 1000 --ignorelength --raw-bits 16 --raw-rate 48000 --raw-chan 6 - "H:\Output\test.opus

the channel order is messed up.
Using:

ffmpeg -y -threads 8 -loglevel fatal -i "H:\Output\test.ac3" -ac 6 -ar 48000 -f sox - | sox --multi-threaded --ignore-length --temp "H:\Temp" --buffer
 524288 -S -t sox - -t raw -b 16 - | opusenc --bitrate 192 --comp 10 --framesize 20 --expect-loss 0 --max-delay 1000 --ignorelength --raw --raw-bits 16 --raw-rate 48000 --raw-chan 6 - "H:\Output\test.opus"

channels are still messed up, but in another way.

Checked LameXP, and from the look of it, LameXP avoids the problem by creating a temporal wav file.

Found a workaround by using flac as intermediate:

ffmpeg -y -threads 8 -loglevel fatal -i "H:\Output\test.ac3" -ac 6 -ar 48000 -f sox - | sox --multi-threaded --ignore-length --temp "H:\Temp" --buffer 524288 -S -t sox - -t flac - | opusenc --bitrate 192 --comp 10 --framesize 20 --expect-loss 0 --max-delay 1000 --ignorelength - "H:\Output\test.opus"

alternatively if sox isn't used

ffmpeg -y -threads 8 -loglevel fatal -i "H:\Output\test.ac3" -ac 6 -ar 48000 -f flac - | opusenc --bitrate 192 --comp 10 --framesize 20 --expect-loss 0 --max-delay 1000 --ignorelength - "H:\Output\test.opus"

in both cases the channel order is correct.

Cu Selur