---
title: magicCookie
framework: avfaudio
role: symbol
role_heading: Instance Property
path: avfaudio/avaudioconverter/magiccookie
---

# magicCookie

An object that contains metadata for encoders and decoders.

## Declaration

```swift
var magicCookie: Data? { get set }
```

## See Also

### Getting Audio Converter Properties

- [channelMap](avfaudio/avaudioconverter/channelmap.md)
- [dither](avfaudio/avaudioconverter/dither.md)
- [downmix](avfaudio/avaudioconverter/downmix.md)
- [inputFormat](avfaudio/avaudioconverter/inputformat.md)
- [outputFormat](avfaudio/avaudioconverter/outputformat.md)
- [maximumOutputPacketSize](avfaudio/avaudioconverter/maximumoutputpacketsize.md)