This tool is written in golang and it simply converts video files using ffmpeg in the same directory to '.ogg' files encoded with the opus codec.
In addition this program uses all available CPUs on the system.
Simply call go build
go build
mv converter ~/bin
Add your ~/bin directory to your $PATH variable.
Then go into your directory where your video files are listed:
cd ~/myVideoDir
Then call the converter
converter # converts all *.mp4 and *.mkv, *.webm to *.ogg
It uses all your available CPUs on the system and calls for every logical CPU ffmpeg.
This program calls ffmpeg. So you have to install it.