---
title: format
framework: audiotoolbox
role: symbol
role_heading: Instance Property
path: audiotoolbox/auaudiounitbus/format
---

# format

The audio format and channel layout of audio being transferred on the bus.

## Declaration

```swift
var format: AVAudioFormat { get }
```

## Discussion

Discussion This version 3 property is bridged to the version 2 kAudioUnitProperty_StreamFormat API.

## See Also

### Bus Methods and Properties

- [setFormat(_:)](audiotoolbox/auaudiounitbus/setformat(_:).md)
- [isEnabled](audiotoolbox/auaudiounitbus/isenabled.md)
- [name](audiotoolbox/auaudiounitbus/name.md)
- [index](audiotoolbox/auaudiounitbus/index.md)
- [busType](audiotoolbox/auaudiounitbus/bustype.md)
- [ownerAudioUnit](audiotoolbox/auaudiounitbus/owneraudiounit.md)
- [supportedChannelLayoutTags](audiotoolbox/auaudiounitbus/supportedchannellayouttags.md)
- [contextPresentationLatency](audiotoolbox/auaudiounitbus/contextpresentationlatency.md)
- [shouldAllocateBuffer](audiotoolbox/auaudiounitbus/shouldallocatebuffer.md)