Is it possible to list all RemoteIO audio units currently in the application?

Question

I'd like to add an output render callback via AudioUnitAddRenderNotify onto the currently active RemoteIO unit that's outputting audio to the speakers. I don't have access to the actual RemoteIO instance variable, but I'd like to get a list audio units in the app and find the RemoteIO unit that way. Is this even possible?

Answer 1

If you can gain acces to the AUGraph then this is possible. According to the AUGraph documentation there is a couple of methods that would help you.

AUGraphGetNodeCount - to get the number of nodes in a graph AUGraphGetIndNode - to get an indexed node AUGraphNodeInfo - to get information about a node

Once you had the correct node you could get the remoteIO unit and add your callback. Gaining access to the AUGraph is actually the real issue.