Calling sync() in loops may end up looping forever if the operating
system's scheduling allows pipewire to reply to this sync() before
wireplumber's event loop has a chance to become idle.
In order for the new ports to appear, the object manager that monitors
them needs to emit "objects-changed", which only ever happens in an
idle callback. If the reply to sync() arrives before the idle callback,
it gets prioritized and processed, which causes another sync(), and so on...
Since setting PortFormat in the adapter always changes the ports,
watching for "ports-changed" feels like a better solution. Still,
there is more room for improvement.
And be careful not to handle nodes created by si-audio-endpoint,
by using a specific property for that.
Also, use Audio/{Source,Sink}/Virtual as the media class of null sinks
created by si-audio-endpoint, it sounds more appropriate.
Fixes#34
We have ended up not using them, so let's not carry them
in the ABI of 0.4
We can always revert that, but let's first decide how
these objects should be used
This allows the channelVolumes and mute props to affect the output
of the null sink's monitor ports. This way we will be able to use
channelVolumes to track the configured volume of the endpoint
and the monitorVolumes to implement volume ducking.
