#!/usr/bin/env fish

function find-stereo -d 'Finds files that are stereo'
	set filter 'pan=mono|c0=0.5*FL+-0.5*FR,silenceremove=start_periods=1:detection=peak'

	for f in $argv
		set out (ffmpeg -nostdin -loglevel error -i "$f" -filter_complex "$filter" -t 0.00002 -f crc -)

		if test "$out" != 'CRC=0x00000001'
			set other /tmp/(basename "$f")
			echo "$f is stereo, converting"
			ffmpeg -i "$f" -ac 1 "$other" && mv "$other" "$f"
		else
			echo "$f is mono"
		end
	end
end

## EOF