---
title: channelMap
framework: avfaudio
role: symbol
role_heading: Instance Property
path: avfaudio/avaudioconverter/channelmap
---

# channelMap

An array of integers that indicates which input to derive each output from.

## Declaration

```swift
var channelMap: [NSNumber] { get set }
```

## Discussion

Discussion The array size equals the number of output channels. Each element’s value is the input channel number, starting with zero, that the framework copies to that output. A negative value means that the output channel doesn’t have a source and is silent. Setting a channel map overrides channel mapping due to any channel layouts in the input and output formats that you supply.

## See Also

### Getting Audio Converter Properties

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