Audio Unit: Use sound output as input source

Question

I want to process the stereo output from iOS devices, no matter what application causes them and visualize it in real-time. Is it possible to use the generic output device (or anything else) to get at the audio data which are currently being played? Maybe as an input to a remoteIO unit?

In other words: I want to do what aurioTouch2 does (FFT only) but instead of using the microphone as input source, I want to process everything which is coming out of the speakers at a given time.

Kind regards

Answer 1

If your own app is playing using the RemoteIO Audio Unit, you can capture that content. You can not capture audio your app is playing using many of the other audio APIs. The iOS security sandbox will prevent your app from capturing audio that any other app is playing (unless that app explicitly exports audio via the Inter-App Audio API or equivalent).