---
title: "init(audioTracks:audioSettings:)"
framework: avfoundation
role: symbol
role_heading: Initializer
path: "avfoundation/avassetreaderaudiomixoutput/init(audiotracks:audiosettings:)"
---

# init(audioTracks:audioSettings:)

Creates an object that reads mixed audio from the specified audio tracks.

## Declaration

```swift
init(audioTracks: [AVAssetTrack], audioSettings: [String : Any]?)
```

## Parameters

- `audioTracks`: An array of track objects of type doc://com.apple.avfoundation/documentation/AVFoundation/AVMediaType/audio from which to source the sample buffers to mix.
- `audioSettings`: Optional audio settings to use for audio output. Pass nil to receive the decoded samples in an uncompressed format. To determine the specific format, examine the value of the sample buffer’s doc://com.apple.documentation/documentation/CoreMedia/CMSampleBuffer/formatDescription property. For non-nil audio settings, the dictionary must contain values for the doc://com.apple.avfoundation/documentation/AVFoundation/linear-pcm-format-settings keys. The output doesn’t support the doc://com.apple.documentation/documentation/AVFAudio/AVSampleRateConverterAudioQualityKey constant.