3. video to crop sequence and sound cycles (linux)

#!/bin/bash
for a in *.mp4
do
#cd ./sequence3
mkdir ./sequence3/${a%.mp4}

ffmpeg -i "$a" -vf: "crop=1920:1080:100:24" -threads 8 -r 30 -qscale:v 2 sequence3/${a%.mp4}/${a%.mp4}_%05d.png
ffmpeg -i "$a" -threads 8 -vn -ar 44100 -ac 2 -ab 194k -f mp3 sequence3/${a%.mp4}/${a%.mp4}.mp3

done