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# kExtAudioFileProperty_FileChannelLayout

A file’s channel layout.

```
var kExtAudioFileProperty_FileChannelLayout: ExtAudioFilePropertyID { get }
```

## Discussion

A file’s channel layout. Value is a read/write <doc://com.apple.documentation/documentation/CoreAudioTypes/AudioChannelLayout> struct.

## Discussion

When writing, the channel layout is written to the file, if the format specified in the `kExtAudioFileProperty_FileDataFormat` property supports the layout. If the format does not support the layout, the channel layout is still interpreted as the destination layout when performing conversion from the client channel layout, if any.

When reading, the specified layout overrides the one read from the file, if one is present in the file.

You must set this property before setting the application audio data format or application channel layout in the extended audio file object.

---

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