Problem with Apple Display Audio simultaneous I/O


I am using two AudioDeviceManager instances, one for input and one for output (I know one AudioDeviceManager can handle input *and* output but only when the sample rate is the same).

I have an Apple monitor with built-in audio. The first AudioDeviceManager to select the "Display Audio" device works fine, but when the other one selects it, it's audioDeviceAboutToStart() callback is called but audioDeviceIOCallback() is not.

What could be wrong? Where can I look for problems?





Can't think of any reason why it'd not work. Even if you tried opening the same device twice it should be fine. Probably a silly mistake?


I'm pretty sure there's something wrong, as I could reproduce it with two different USB devices on OSX, and trying with AudioDeviceManager or directly with AudioIODevices.

What is working ok though is to use one AudioDeviceManager, and if it can't open the specified input and output devices (probably because they have no common sample rate) then I use seprate AudioDeviceManagers for input and output.



That's what you'd expect to see if the device driver refuses to allow more than one client. The AudioDeviceManager only opens the midi port once, and then shares it between its listeners.