Output Audio Unit Services Reference

Overview

This document describes Output Audio Unit Services, a C interface in the Audio Unit framework. You use this interface to start and stop I/O audio units (often referred to as output audio units).

Functions

AudioOutputUnitStart

Starts an I/O audio unit, which in turn starts the audio unit processing graph that it is connected to.

OSStatus AudioOutputUnitStart (
   AudioUnit ci
);

AudioOutputUnitStop

Stops an I/O audio unit, which in turn stops the audio unit processing graph that it is connected to.

OSStatus AudioOutputUnitStop (
   AudioUnit ci
);

Constants

I/O Audio Unit Function Selectors

Audio unit component selectors, specific to I/O audio units, that correspond to functions in the audio unit API.

enum {
   kAudioOutputUnitRange          = 0x0200, // selector range
   kAudioOutputUnitStartSelect    = 0x0201,
   kAudioOutputUnitStopSelect     = 0x0202
};

Constants

kAudioOutputUnitRange

The start of the numerical range for I/O audio unit function selectors.

Available in iOS 2.0 and later.

Declared in AudioOutputUnit.h.

kAudioOutputUnitStartSelect

Used by the system to start an I/O audio unit when you call the AudioOutputUnitStart function.

Available in iOS 2.0 and later.

Declared in AudioOutputUnit.h.

kAudioOutputUnitStopSelect

Used by the system to stop an I/O audio unit when you call the AudioOutputUnitStop function.

Available in iOS 2.0 and later.

Declared in AudioOutputUnit.h.