heiwiper Unfortunately not. Firefox introduced the MediaStream API and exposed it over MPRIS and other mechanisms to enable "hardware key" support, so whenever there is audio playing it will expose that "stream" (not as in a livestream but a pulseaudio playback stream) over MPRIS, which then gets handled by the media keys. You can disable this functionality if you find it to be a nuisance by setting media.hardwaremediakeys.enabled
to false
via about:config
in firefox. This will disable its ability to expose over MPRIS.
Discord does the same thing with basically any sounds played, typically notification streams. They're typically temporary and almost immediately the playback streams are closed, but it depends on the usecase.
Lollypop, Spotify, etc. are the media players that are most typically persistent so long as the application is open.