---
title: AudioOutputUnitMIDICallbacks
framework: audiotoolbox
role: symbol
role_heading: Structure
path: audiotoolbox/audiooutputunitmidicallbacks
---

# AudioOutputUnitMIDICallbacks

## Declaration

```swift
struct AudioOutputUnitMIDICallbacks
```

## Topics

### Initializers

- [init(userData:MIDIEventProc:MIDISysExProc:)](audiotoolbox/audiooutputunitmidicallbacks/init(userdata:midieventproc:midisysexproc:).md)

### Instance Properties

- [MIDIEventProc](audiotoolbox/audiooutputunitmidicallbacks/midieventproc.md)
- [MIDISysExProc](audiotoolbox/audiooutputunitmidicallbacks/midisysexproc.md)
- [userData](audiotoolbox/audiooutputunitmidicallbacks/userdata.md)

## Relationships

### Conforms To

- [BitwiseCopyable](swift/bitwisecopyable.md)

## See Also

### Input/Output

- [I/O Audio Unit Properties](audiotoolbox/1534116-i_o_audio_unit_properties.md)
- [Inter-App Output Unit Property IDs](audiotoolbox/1621039-inter-app-output-unit-property-ids.md)
- [Inter-App Audio Unit Property IDs](audiotoolbox/1621038-inter-app-audio-unit-property-ids.md)
- [Output Unit Parameters](audiotoolbox/1389916-output_unit_parameters.md)
- [AUNetReceive Properties](audiotoolbox/1534109-aunetreceive-properties.md)
- [AUNetSend Properties](audiotoolbox/1534207-aunetsend-properties.md)
- [AUNetSend Parameters](audiotoolbox/1389633-aunetsend-parameters.md)
- [AUNetReceive Parameters](audiotoolbox/1389920-aunetreceive-parameters.md)
- [AUNetSendPresetFormat Properties](audiotoolbox/1534212-aunetsendpresetformat-properties.md)
- [Net Status Audio Unit Parameters](audiotoolbox/1389891-net-status-audio-unit-parameters.md)
- [I/O Audio Unit Function Selectors](audiotoolbox/1585807-i_o_audio_unit_function_selector.md)
- [AudioOutputUnitStartAtTimeParams](audiotoolbox/audiooutputunitstartattimeparams.md)