I have some .wav files and I would like to convert their frequency (fs) and number of channels (nchannels). I am using ffmpeg on a jupyter notebook, python3.6 but using linux command line with a system call. I used the following command and it works.
cmd= 'ffmpeg -i %s -ar %d -ac %d %s.wav'%(filepath,fs,nchannel,wavfilename) os.system(cmd)
However, when converting two channels into a single channel, I just want ffmpeg takes only left (or right) channel instead of an average of two signal? If I use map channel as follow would that be correct? This creates wav files but I am not sure if only one channel is taken.
'ffmpeg -i %s -ar %d -map_channel 0.0.0 %s.wav(filepath,fs,wavfilename)'
If not, how can I modify my code above to achieve that? I also tried;
'ffmpeg -i %s -af channelsplit=channel_layout=stereo:channels=FL -ar %d %s.wav'%(filepath,fs,wavfilename)'
but this created empty wav files.