Gregory's Server@hailey yeah, but the issue is the multi-room control via mpd audio_outputs if I'm not mistaken.
To control which rooms should be enabled from within mpd, I need multiple audio_outputs in mpd, some are enabled and some disabled. Now these should integrate again into one bark stream to allow it to do it's multiroom magic. Or maybe some other logic to check which rooms are enabled in mpd.
This would allow me to use the many different mpd clients to control the whole stack: playlist, song, volume and rooms.
@electronic_eel I see! You could achieve this by creating separate virtual devices and running multiple bark stream processes using separate multicast groups for each speaker. You'd lose the benefit of multicast, since you'd essentially be unicasting to each speaker (but in a roundabout way via multicast), but the actual synchronisation runs according to CLOCK_BOOTTIME on the source host, so provided all stream sources are running on the same machine the sync would work.