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# AUAudioUnitBus

A class that defines an input or output connection point on an audio unit.

```
class AUAudioUnitBus
```

## Topics

### Bus Methods and Properties

[`-  setFormat:error:`](/documentation/AudioToolbox/AUAudioUnitBus/setFormat(_:))

Sets the bus’s audio format.

[`format`](/documentation/AudioToolbox/AUAudioUnitBus/format)

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

[`enabled`](/documentation/AudioToolbox/AUAudioUnitBus/isEnabled)

Determines whether the bus is active.

[`name`](/documentation/AudioToolbox/AUAudioUnitBus/name)

A name for the bus.

[`index`](/documentation/AudioToolbox/AUAudioUnitBus/index)

The index of this bus in its containing array.

[`busType`](/documentation/AudioToolbox/AUAudioUnitBus/busType)

The bus type.

[`ownerAudioUnit`](/documentation/AudioToolbox/AUAudioUnitBus/ownerAudioUnit)

The audio unit that owns the bus.

[`supportedChannelLayoutTags`](/documentation/AudioToolbox/AUAudioUnitBus/supportedChannelLayoutTags)

An array of audio channel layout tags.

[`contextPresentationLatency`](/documentation/AudioToolbox/AUAudioUnitBus/contextPresentationLatency)

Information about latency in the audio unit’s processing context.

[`shouldAllocateBuffer`](/documentation/AudioToolbox/AUAudioUnitBus/shouldAllocateBuffer)

### Audio Unit Implementations

These methods and properties are only of interest to audio unit subclasses.

[`-  initWithFormat:error:`](/documentation/AudioToolbox/AUAudioUnitBus/init(format:))

Initializes a bus object with a specific format.

[`supportedChannelCounts`](/documentation/AudioToolbox/AUAudioUnitBus/supportedChannelCounts)

An array of numbers indicating the supported number of channels for this bus.

[`maximumChannelCount`](/documentation/AudioToolbox/AUAudioUnitBus/maximumChannelCount)

The maximum number of channels supported for this bus.

## Relationships

### Conforms To

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

[`Hashable`](/documentation/Swift/Hashable)

[`Equatable`](/documentation/Swift/Equatable)

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

[`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol)

[`CVarArg`](/documentation/Swift/CVarArg)

### Inherits From

[`NSObject-swift.class`](/documentation/ObjectiveC/NSObject-swift.class)

---

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