iOS Developer Library

Developer

AudioUnit Framework Reference Output Audio Unit Services Reference

Options
Deployment Target:

On This Page
Language:

Output Audio Unit Services Reference

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

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

    Declaration

    Swift

    func AudioOutputUnitStart(_ ci: AudioUnit) -> OSStatus

    Objective-C

    OSStatus AudioOutputUnitStart ( AudioUnit ci );

    Parameters

    ci

    The I/O audio unit to start.

    Return Value

    A result code.

    Import Statement

    import AudioUnit

    Availability

    Available in iOS 2.0 and later.

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

    Declaration

    Swift

    func AudioOutputUnitStop(_ ci: AudioUnit) -> OSStatus

    Objective-C

    OSStatus AudioOutputUnitStop ( AudioUnit ci );

    Parameters

    ci

    The I/O audio unit to stop.

    Return Value

    A result code.

    Import Statement

    import AudioUnit

    Availability

    Available in iOS 2.0 and later.

Constants

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

    Declaration

    Swift

    var kAudioOutputUnitRange: Int { get } var kAudioOutputUnitStartSelect: Int { get } var kAudioOutputUnitStopSelect: Int { get }

    Objective-C

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

    Constants

    • kAudioOutputUnitRange

      kAudioOutputUnitRange

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

      Available in iOS 2.0 and later.

    • kAudioOutputUnitStartSelect

      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.

    • kAudioOutputUnitStopSelect

      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.

    Import Statement