--- title: "mutableChannelData(_:)" framework: avfaudio role: symbol role_heading: Instance Method path: "avfaudio/avaudiopcmbuffer/mutablechanneldata(_:)" --- # mutableChannelData(_:) Returns mutable access to a specific channel’s data. ## Declaration ```swift func mutableChannelData(_ index: Int) -> AVAudioPCMBuffer.MutableChannelData ``` ## Parameters - `index`: The zero-based channel index. ## Return Value Return Value A MutableChannelData enum containing the channel’s sample data. ## Discussion Discussion The returned MutableChannelData is tied to the lifetime of this buffer and provides type-safe mutable access to the channel’s sample data. Example: warning: This function cannot enforce exclusivity at compile time because AVAudioPCMBuffer is an Objective-C class. The caller must ensure they don’t create overlapping mutable views to the same memory. It is safe to access different channels simultaneously or different regions of the same channel. note: Provides access to the entire buffer (up to frameCapacity). frameLength needs to be updated if the size changes. for channelIndex in 0..