the version of ffmpeg that comes installed on pop os 22.04 is version 4.4.2, which doesn’t come with libsvtav1 to make avif files and doesn’t work well with ffmpeg-normalize. i followed this tutorial to install it but got the version here. also see another av1 encoding tutorial here.
sudo apt remove ffmpeg
sudo mkdir -p /opt/ffmpeg
cd /opt/ffmpeg
sudo wget https://github.com/BtbN/FFmpeg-Builds/releases/download/latest/ffmpeg-master-latest-linux64-gpl.tar.xz
sudo tar xvf ffmpeg-master-latest-linux64-gpl.tar.xz
cd ffmpeg-*-gpl/bin/
sudo ln -s "${PWD}/ffmpeg" /usr/bin/
sudo ln -s "${PWD}/ffprobe" /usr/bin/
sudo ln -s "${PWD}/ffplay" /usr/bin/