---
title: "init(inputToOutputCallback:userData:)"
framework: audiotoolbox
role: symbol
role_heading: Initializer
path: "audiotoolbox/auinputsamplesinoutputcallbackstruct/init(inputtooutputcallback:userdata:)"
---

# init(inputToOutputCallback:userData:)

## Declaration

```swift
init(inputToOutputCallback: AUInputSamplesInOutputCallback, userData: UnsafeMutableRawPointer?)
```