---
title: mutableAudioBufferList
framework: avfaudio
role: symbol
role_heading: Instance Property
path: avfaudio/avaudiobuffer/mutableaudiobufferlist
---

# mutableAudioBufferList

A mutable version of the buffer’s underlying audio buffer list.

## Declaration

```swift
var mutableAudioBufferList: UnsafeMutablePointer<AudioBufferList> { get }
```

## Discussion

Discussion You use this with some lower-level Core Audio and Audio Toolbox APIs that require a mutable AudioBufferList (for example, the AudioConverterConvertComplexBuffer(_:_:_:_:) function). The mDataByteSize fields of this audio buffer list express the buffer’s current frameCapacity. If you alter the capacity, modify the buffer’s frameLength to match.

## See Also

### Getting the Audio Buffers

- [audioBufferList](avfaudio/avaudiobuffer/audiobufferlist.md)