---
title: AVAudioSourceNodeRenderBlock
framework: avfaudio
role: symbol
role_heading: Type Alias
path: avfaudio/avaudiosourcenoderenderblock
---

# AVAudioSourceNodeRenderBlock

A block that supplies audio data to an audio source node.

## Declaration

```swift
typealias AVAudioSourceNodeRenderBlock = (UnsafeMutablePointer<ObjCBool>, UnsafePointer<AudioTimeStamp>, AVAudioFrameCount, UnsafeMutablePointer<AudioBufferList>) -> OSStatus
```

## Parameters

- `isSilence`: The Boolean value that indicates whether the buffer contains only silence.
- `timestamp`: The HAL time the audio data renders.
- `frameCount`: The number of sample frames of audio data the engine requests.
- `outputData`: The output data.

## Return Value

Return Value An OSStatus result code. When returning an error, consider the audio data invalid.

## See Also

### Creating an Audio Source Node

- [init(renderBlock:)](avfaudio/avaudiosourcenode/init(renderblock:).md)
- [init(format:renderBlock:)](avfaudio/avaudiosourcenode/init(format:renderblock:).md)