These are the MimeType= values of various apps in /usr/share/applications/.
- https://github.com/KDE/elisa/blob/master/org.kde.elisa.desktop.cmake
- https://github.com/clementine-player/Clementine/blob/master/dist/org.clementine_player.Clementine.desktop
- https://github.com/KDE/haruna/blob/master/data/org.kde.haruna.desktop
- https://github.com/mpv-player/mpv/blob/master/etc/mpv.desktop
- https://github.com/videolan/vlc/blob/master/share/vlc.desktop.mimetypes
- https://github.com/KDE/gwenview/blob/8b310b1d72930eef25357313e3497b61f79dbafb/CMakeLists.txt#L152