Vaguely relevant to this thread, I wrote a bash script that converts all sound files of a specified type in a folder - e.g. flac - to mp3 - so I could put them on an SD card. It's here.

It contains the same loop as Guest's script. The ffmpeg command could be modified to add other processing - e.g. a volume filter - and 'mp3' could be changed to another file type.

As I said, you can run bash in Windows 10 - I've tried it. There is a utility called Cygwin which runs bash scripts in earlier versions of Windows - though I've never used it.