Make screenshot, blur it and save - very fast

blur-screenshot.sh

#!/usr/bin/env bash

ffmpeg -loglevel panic\
       -f x11grab\
       -video_size $(xdpyinfo | grep dimensions | sed -r 's/^[^0-9]*([0-9]+x[0-9]+).*$/\1/')\
       -y -i :0.0\
       -filter_complex "boxblur=9"\
       -vframes 1\
       /tmp/i3lock.png