RecordScreen.sh

#!/bin/sh
ffmpeg -framerate 25 -video_size 1920x1080 -f x11grab -i :0.0+1920,0 -f alsa -ac 2 -i pulse -vcodec libx264 -crf 0 -preset ultrafast -strict -2 screenrecord.mp4
echo "Re-encoding to use less space"

# Find a file name that doesn't exist yet
fileending=""

if [ -f screenrecord_encoded_$fileending.mp4 ]
then

    fileending="2"

    while [ -f screenrecord_encoded_$fileending.mp4 ]
    do

        fileending=$((fileending + 1))
    done
fi 

echo "Encoding final file screenrecord_encoded_$fileending.mp4"

ffmpeg -i screenrecord.mp4 -strict -2 screenrecord_encoded_$fileending.mp4

echo "Deleting raw file"
rm screenrecord.mp4