---
title: kAudioOutputUnitProperty_SetInputCallback
framework: audiotoolbox
role: symbol
role_heading: Global Variable
path: audiotoolbox/kaudiooutputunitproperty_setinputcallback
---

# kAudioOutputUnitProperty_SetInputCallback

A read/write AURenderCallbackStruct data structure valid on the audio unit global scope. When an output unit has been enabled for input operation, this callback can be used to provide a single callback to the host application from the input I/O proc, in order to notify the host that input is available and may be obtained by calling the AudioUnitRender function.

## Declaration

```swift
var kAudioOutputUnitProperty_SetInputCallback: AudioUnitPropertyID { get }
```

## See Also

### Properties

- [kAudioOutputUnitProperty_ChannelMap](audiotoolbox/kaudiooutputunitproperty_channelmap.md)
- [kAudioOutputUnitProperty_CurrentDevice](audiotoolbox/kaudiooutputunitproperty_currentdevice.md)
- [kAudioOutputUnitProperty_EnableIO](audiotoolbox/kaudiooutputunitproperty_enableio.md)
- [kAudioOutputUnitProperty_HasIO](audiotoolbox/kaudiooutputunitproperty_hasio.md)
- [kAudioOutputUnitProperty_StartTime](audiotoolbox/kaudiooutputunitproperty_starttime.md)
- [kAudioOutputUnitProperty_StartTimestampsAtZero](audiotoolbox/kaudiooutputunitproperty_starttimestampsatzero.md)
- [kAudioOutputUnitProperty_IsRunning](audiotoolbox/kaudiooutputunitproperty_isrunning.md)