#!/bin/sh
compare() {
    cd out
    for i in *; do
        if [ `du "$i" | cut -f1` -lt `du ../"$i" | cut -f1` ]; then
            echo $i
            mv "$i" ../"$i"
        fi
    done
    cd ..
}

mkdir out

args="-af aresample=resampler=soxr:precision=32:dither_method=triangular -sample_fmt s16"
fd -e flac -d1 -x ffmpeg -hide_banner -i {} -c:v copy -c:a flac -compression_level 12 $args $@ out/{}
compare

fd -e flac -d1 -x flac -f8 {} -o out/{}
compare

rm -r out