---
title: "init(userData:MIDIEventProc:MIDISysExProc:)"
framework: audiotoolbox
role: symbol
role_heading: Initializer
path: "audiotoolbox/audiooutputunitmidicallbacks/init(userdata:midieventproc:midisysexproc:)"
---

# init(userData:MIDIEventProc:MIDISysExProc:)

## Declaration

```swift
init(userData: UnsafeMutableRawPointer?, MIDIEventProc: (UnsafeMutableRawPointer?, UInt32, UInt32, UInt32, UInt32) -> Void, MIDISysExProc: (UnsafeMutableRawPointer?, UnsafePointer<UInt8>, UInt32) -> Void)
```