Separate A Channel from A Track

[jagabo]

The third digit in "0.0.0" is the channel number you want to keep. 0 is left, 1 is right.

[niteghost]

The third digit in "0.0.0" is the channel number you want to keep. 0 is left, 1 is right.

Thanks again,appreciate the response. This is the first time I came across RMVB files w/Dual language with my desired Language [ Cantonese] in the Right
Mono,usually almost all the time is on the Left. That was why the question.

I changed your code to this as you suggested, works Great !!

mkdir mono
for %%F in (*.rmvb) do (
    ffmpeg -i "%%~dpnxF" -map_channel 0.0.0 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
    ffmpeg -i "%%~dpnxF" -map_channel 0.0.1 -c:v copy -c:a aac -b:a 160k "mono\%%~nF.mkv"
)