To make VLC the default media player for most video and audio formats …
(obviously you’ll need to have VLC installed first)
First backup your current users ~/.local/share/applications/mimeapps.list by opening a terminal (Ctrl+Alt+T), and run:
cp -vf ~/.local/share/applications/mimeapps.list ~/.local/share/applications/mimeapps.list.backup
Ok now lets add the mimetypes for audio:
grep "^MimeType=" /usr/share/applications/vlc.desktop | cut -d "=" -f 2 | xargs -d ';' -n 1 | grep -e "^audio/" -e "^x-content/audio" | xargs -n 1 -I '{}' xdg-mime default vlc.desktop '{}'
and now for video:
grep "^MimeType=" /usr/share/applications/vlc.desktop | cut -d "=" -f 2 | xargs -d ';' -n 1 | grep -e "^video/" -e "^x-content/video" | xargs -n 1 -I '{}' xdg-mime default vlc.desktop '{}'
There may be a few filetypes that were missed, but those can be added in the normal way -
Right-click on the file, select “Open With”, select VLC, and tick the box “Set as default”.
But those commands will add all VLC’s defaults (as gleaned from the vlc.desktop file)
If anything goes wrong … you can undo this by running:
cp -vf ~/.local/share/applications/mimeapps.list.backup ~/.local/share/applications/mimeapps.list