Normalize audio files in dir and subdir

normalize.sh

#!/usr/bin/env bash

cd $1
find . type f | grep mp3$ > mp3-files.txt

readarray -t files < mp3-files.txt

INDEX=0
LENGTH=${#files[@]}

for file in "${files[@]}"; do
    INDEX=$((INDEX+1))
    percent=$(printf '%i %i' $INDEX $LENGTH | awk '{ pc=100*$1/$2; i=int(pc); print (pc-i<0.5)?i:i+1 }')
    echo "Converting... [$percent%] $file"

    ffmpeg -loglevel panic -i "$file" -vn -ar 44100 -ac 2 -q:a 5 temp.mp3;
    rm "$file";
    mv temp.mp3 "$file";
done

echo "All done!"