I would like do a batch that analise the input source (mp4, flv, avi, mpg ecc..) and try to extract whatever audio is present, if present.

And generate a .wav file pcm_s16le L+R (stereo) 48 khz

if source audio multiple audio channel, only the 1 and 2 are choosed

I have try

ffmpeg.exe -y -i input.mp4 -filter_complex "[0:1] volume=1.5" -c:a pcm_s16le output.wav

but I'm not shure if acts over all type of audio present, and I'm not shure If is possible do a batch of this kind