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# init

Initializes an instance of the audio stream class.

```
virtual bool init(IOUserAudioDriver *in_driver, IOUserAudioStreamDirection in_direction, IOMemoryDescriptor *in_io_memory_descriptor);
```

## Parameters

`in_driver`

The [`IOUserAudioDriver`](/documentation/AudioDriverKit/IOUserAudioDriver) that owns this object.

`in_direction`

A `IOUserAudioStreamDirection` for the stream’s direction: input or output.

`in_io_memory_descriptor`

A pointer to a <doc://com.apple.documentation/documentation/DriverKit/IOMemoryDescriptor>. The stream maps the descriptor’s buffer to the Host for doing audio I/O.

## Return Value

`true` if initialization succeeded; `false` otherwise.

---

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