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# MTAudioProcessingTapCallbacks

A structure that defines life cycle callbacks for an audio processing tap object.

```
struct MTAudioProcessingTapCallbacks
```

## Overview

On 64-bit architectures, this struct contains misaligned function pointers. To avoid link-time issues, fill its function pointer fields by using assignment statements, rather than declaring them as global or static structs.

## Topics

### Fields

[`var version: Int32`](/documentation/MediaToolbox/MTAudioProcessingTapCallbacks/version)

The version number of the structure.

[`var clientInfo: UnsafeMutableRawPointer?`](/documentation/MediaToolbox/MTAudioProcessingTapCallbacks/clientInfo)

App data that the system passes to the initialization callback.

[`var `init`: MTAudioProcessingTapInitCallback?`](/documentation/MediaToolbox/MTAudioProcessingTapCallbacks/init)

A callback to initialize the tap processor.

[`var finalize: MTAudioProcessingTapFinalizeCallback?`](/documentation/MediaToolbox/MTAudioProcessingTapCallbacks/finalize)

A callback to perform any necessary cleanup.

[`var prepare: MTAudioProcessingTapPrepareCallback?`](/documentation/MediaToolbox/MTAudioProcessingTapCallbacks/prepare)

A callback to prepare the tap processor.

[`var unprepare: MTAudioProcessingTapUnprepareCallback?`](/documentation/MediaToolbox/MTAudioProcessingTapCallbacks/unprepare)

A callback to perform any necessary cleanup for previous preparation.

[`var process: MTAudioProcessingTapProcessCallback`](/documentation/MediaToolbox/MTAudioProcessingTapCallbacks/process)

A callback for processing the audio.

### Callback functions

[`typealias MTAudioProcessingTapInitCallback`](/documentation/MediaToolbox/MTAudioProcessingTapInitCallback)

An initialization callback function.

[`typealias MTAudioProcessingTapPrepareCallback`](/documentation/MediaToolbox/MTAudioProcessingTapPrepareCallback)

An audio processing preparation callback function.

[`typealias MTAudioProcessingTapProcessCallback`](/documentation/MediaToolbox/MTAudioProcessingTapProcessCallback)

An audio processing callback function.

[`typealias MTAudioProcessingTapUnprepareCallback`](/documentation/MediaToolbox/MTAudioProcessingTapUnprepareCallback)

An audio processing unpreparation callback function.

[`typealias MTAudioProcessingTapFinalizeCallback`](/documentation/MediaToolbox/MTAudioProcessingTapFinalizeCallback)

A finalization callback function.

### Versions

[`var kMTAudioProcessingTapCallbacksVersion_0: Int32`](/documentation/MediaToolbox/kMTAudioProcessingTapCallbacksVersion_0)

An identifier for version 0 of the callbacks structure.

### Initializers

[`init(version: Int32, clientInfo: UnsafeMutableRawPointer?, init: MTAudioProcessingTapInitCallback?, finalize: MTAudioProcessingTapFinalizeCallback?, prepare: MTAudioProcessingTapPrepareCallback?, unprepare: MTAudioProcessingTapUnprepareCallback?, process: MTAudioProcessingTapProcessCallback)`](/documentation/MediaToolbox/MTAudioProcessingTapCallbacks/init(version:clientInfo:init:finalize:prepare:unprepare:process:))

## Relationships

### Conforms To

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

---

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