# ManagedAudioChannelLayout This structure is used to specify channel layouts in files and hardware. ``` struct ManagedAudioChannelLayout ``` ## Topics ### Structures [`struct ChannelDescriptions`](/documentation/CoreAudio/ManagedAudioChannelLayout/ChannelDescriptions-swift.struct) A collection of `AudioChannelDescription`s. ### Initializers [`init(audioChannelLayoutPointer: AudioChannelLayout.UnsafePointer, deallocator: (AudioChannelLayout.UnsafePointer) -> Void)`](/documentation/CoreAudio/ManagedAudioChannelLayout/init(audioChannelLayoutPointer:deallocator:)) Creates a new `ManagedAudioChannelLayout` from an existing pointer to an `AudioChannelLayout`. [`init(channelDescriptions: [AudioChannelDescription])`](/documentation/CoreAudio/ManagedAudioChannelLayout/init(channelDescriptions:)) Creates a new `ManagedAudioChannelLayout` from an array of `AudioChannelDescription`. [`init(maximumDescriptions: Int)`](/documentation/CoreAudio/ManagedAudioChannelLayout/init(maximumDescriptions:)) Creates a new `ManagedAudioChannelLayout` that can hold up to `maximumDescriptions`. [`init(tag: AudioChannelLayoutTag)`](/documentation/CoreAudio/ManagedAudioChannelLayout/init(tag:)) Creates a new `ManagedAudioChannelLayout` with a given tag. ### Instance Properties [`var bitmap: AudioChannelBitmap`](/documentation/CoreAudio/ManagedAudioChannelLayout/bitmap) If `tag` is set to `kAudioChannelLayoutTag_UseChannelBitmap`, this is the channel usage bitmap. [`var channelDescriptions: ManagedAudioChannelLayout.ChannelDescriptions`](/documentation/CoreAudio/ManagedAudioChannelLayout/channelDescriptions-swift.property) The `AudioChannelDescription`s that describe the layout. [`var numberOfChannels: Int`](/documentation/CoreAudio/ManagedAudioChannelLayout/numberOfChannels) The number of channels described by this `ManagedAudioChannelLayout`. [`var sizeInBytes: Int`](/documentation/CoreAudio/ManagedAudioChannelLayout/sizeInBytes) The size, in bytes, of the backing `AudioChannelLayout`. [`var tag: AudioChannelLayoutTag`](/documentation/CoreAudio/ManagedAudioChannelLayout/tag) The `AudioChannelLayoutTag` that indicates the layout. ### Instance Methods [`func setAllToUnknown()`](/documentation/CoreAudio/ManagedAudioChannelLayout/setAllToUnknown()) Sets all `AudioChannelDescriptions` to `kAudioChannelLabel_Unknown`. [`func withUnsafeMutablePointer((UnsafeMutablePointer) throws -> Result) rethrows -> Result`](/documentation/CoreAudio/ManagedAudioChannelLayout/withUnsafeMutablePointer(_:)) Calls a closure with a mutable pointer to the backing `AudioChannelLayout`. [`func withUnsafePointer((UnsafePointer) throws -> Result) rethrows -> Result`](/documentation/CoreAudio/ManagedAudioChannelLayout/withUnsafePointer(_:)) Calls a closure with a pointer to the backing `AudioChannelLayout`. ## Relationships ### Conforms To [`Equatable`](/documentation/Swift/Equatable) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)