---
title: AUInternalRenderBlock
framework: audiotoolbox
role: symbol
role_heading: Type Alias
path: audiotoolbox/auinternalrenderblock
---

# AUInternalRenderBlock

A block to render the audio unit.

## Declaration

```swift
typealias AUInternalRenderBlock = (UnsafeMutablePointer<AudioUnitRenderActionFlags>, UnsafePointer<AudioTimeStamp>, AUAudioFrameCount, Int, UnsafeMutablePointer<AudioBufferList>, UnsafePointer<AURenderEvent>?, AURenderPullInputBlock?) -> AUAudioUnitStatus
```

## Discussion

Discussion This block is implemented in subclasses and should not be used by hosts. The block returns an audio unit status result code. If instead an error is returned, the output data should be assumed to be invalid. The block takes the following parameters:

## See Also

### Customizing the Audio Unit Behavior

- [registerSubclass(_:as:name:version:)](audiotoolbox/auaudiounit/registersubclass(_:as:name:version:).md)
- [shouldChange(to:for:)](audiotoolbox/auaudiounit/shouldchange(to:for:).md)
- [setRenderResourcesAllocated(_:)](audiotoolbox/auaudiounit/setrenderresourcesallocated(_:).md)
- [internalRenderBlock](audiotoolbox/auaudiounit/internalrenderblock.md)
- [midiOutputBufferSizeHint](audiotoolbox/auaudiounit/midioutputbuffersizehint.md)