If I have an audio publisher and an audio subscriber, and the AudioSubscriber.publisherIDs property is left empty, will the subscriber play the audio from the local publisher? If it does, will it play it after a round trip to and from the server (assuming hub&spoke)?
No, in Audio, the local loopback is not done i.e. you won't hear your sound unless you go ahead and make changes suiting your need by subclassing or modifying the AudioSubscriber component.
If you don't do anything on publisherIDs property and leave it empty, it will act as default i.e. publish every stream.
And in hub-spoke, every stream when played is done roundtrip from the server.
So that means, if I'm publishing my microphone audio, and subscribing to all the audio streams, then I will hear an echo of myself after a delay? ( My own published stream after round trip. )
You will never hear your own audio unless you write your subclass for our AudioSubscriber or make changes to it.
We DO NOT have loopback of self audio. In camera , we have loopback i.e. you can see your stream but in audio we don't.
What I meant was in hub-spoke, every stream is streamed by the FMS server.