AVFAudio — Apple framework reference

AVFAudio handles an app's audio through an engine, sessions, playback and recording, mixing, and processing nodes. You build a signal graph by attaching and connecting AVAudioNode instances to an AVAudioEngine, routing audio between an AVAudioInputNode, AVAudioMixerNode, AVAudioEnvironmentNode, and AVAudioOutputNode, and you move sample data with formats and buffers such as AVAudioFormat, AVAudioPCMBuffer, and AVAudioCompressedBuffer. For simpler cases, use AVAudioPlayer to play sound files, read and write audio with AVAudioFile, and convert between formats using AVAudioConverter. Mixing protocols including AVAudioMixing, AVAudioStereoMixing, and AVAudio3DMixing let you position and blend sources, including 3D spatialized output.

Audio Engine 6

Build a signal-processing graph by attaching and connecting audio nodes to an engine.

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AVAudioEngineiOS 8.0+
@class AVAudioEngine
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AVAudioNodeiOS 8.0+
@class AVAudioNode
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AVAudioConnectionPointiOS 9.0+
@class AVAudioConnectionPoint
En
AVAudioEngineManualRenderingErroriOS 11.0+
@enum AVAudioEngineManualRenderingError
En
AVAudioEngineManualRenderingStatusiOS 11.0+
@enum AVAudioEngineManualRenderingStatus
En
AVAudioEngineManualRenderingModeiOS 11.0+
@enum AVAudioEngineManualRenderingMode

Input, Output, and Mixing Nodes 9

Nodes that route audio in and out of the engine and mix or generate sample data.

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AVAudioIONodeiOS 8.0+
@class AVAudioIONode
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AVAudioInputNodeiOS 8.0+
@class AVAudioInputNode
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AVAudioOutputNodeiOS 8.0+
@class AVAudioOutputNode
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AVAudioMixerNodeiOS 8.0+
@class AVAudioMixerNode
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AVAudioPlayerNodeiOS 8.0+
@class AVAudioPlayerNode
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AVAudioSinkNodeiOS 13.0+
@class AVAudioSinkNode
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AVAudioSourceNodeiOS 13.0+
@class AVAudioSourceNode
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AVAudioPlayerNodeBufferOptions
@enum AVAudioPlayerNodeBufferOptions
En
AVAudioPlayerNodeCompletionCallbackType
@enum AVAudioPlayerNodeCompletionCallbackType

Spatial and Environmental Audio 15

Position and render sources in 3D space and apply environmental distance and reverb effects.

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AVAudioEnvironmentNodeiOS 8.0+
@class AVAudioEnvironmentNode
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AVAudioEnvironmentDistanceAttenuationParametersiOS 8.0+
@class AVAudioEnvironmentDistanceAttenuationParameters
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AVAudioEnvironmentReverbParametersiOS 8.0+
@class AVAudioEnvironmentReverbParameters
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AVAudioMixingiOS 8.0+
@protocol AVAudioMixing
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AVAudioStereoMixingiOS 8.0+
@protocol AVAudioStereoMixing
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AVAudio3DMixing
@protocol AVAudio3DMixing
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AVAudioMixingDestinationiOS 9.0+
@class AVAudioMixingDestination
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AVAudio3DPoint
@struct AVAudio3DPoint
St
AVAudio3DVectorOrientation
@struct AVAudio3DVectorOrientation
St
AVAudio3DAngularOrientation
@struct AVAudio3DAngularOrientation
En
AVAudioEnvironmentDistanceAttenuationModeliOS 8.0+
@enum AVAudioEnvironmentDistanceAttenuationModel
En
AVAudioEnvironmentOutputTypeiOS 13.0+
@enum AVAudioEnvironmentOutputType
En
AVAudio3DMixingRenderingAlgorithmiOS 8.0+
@enum AVAudio3DMixingRenderingAlgorithm
En
AVAudio3DMixingSourceModeiOS 13.0+
@enum AVAudio3DMixingSourceMode
En
AVAudio3DMixingPointSourceInHeadModeiOS 13.0+
@enum AVAudio3DMixingPointSourceInHeadMode

Audio Units and Effects 16

Audio unit nodes that apply effects, generate, or process audio within the engine.

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AVAudioUnitiOS 8.0+
@class AVAudioUnit
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AVAudioUnitComponentiOS 9.0+
@class AVAudioUnitComponent
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AVAudioUnitComponentManageriOS 9.0+
@class AVAudioUnitComponentManager
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AVAudioUnitEffectiOS 8.0+
@class AVAudioUnitEffect
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AVAudioUnitGeneratoriOS 8.0+
@class AVAudioUnitGenerator
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AVAudioUnitDelayiOS 8.0+
@class AVAudioUnitDelay
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AVAudioUnitDistortioniOS 8.0+
@class AVAudioUnitDistortion
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AVAudioUnitEQiOS 8.0+
@class AVAudioUnitEQ
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AVAudioUnitEQFilterParametersiOS 8.0+
@class AVAudioUnitEQFilterParameters
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AVAudioUnitReverbiOS 8.0+
@class AVAudioUnitReverb
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AVAudioUnitTimeEffectiOS 8.0+
@class AVAudioUnitTimeEffect
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AVAudioUnitTimePitchiOS 8.0+
@class AVAudioUnitTimePitch
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AVAudioUnitVarispeediOS 8.0+
@class AVAudioUnitVarispeed
En
AVAudioUnitDistortionPresetiOS 8.0+
Constants that specify the preset distortion settings of a distortion effect.
En
AVAudioUnitEQFilterTypeiOS 8.0+
@enum AVAudioUnitEQFilterType
En
AVAudioUnitReverbPresetiOS 8.0+
Constants that specify the preset room settings of a reverb effect.

Formats and Buffers 8

Describe audio stream formats and hold sample data in memory for processing.

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AVAudioFormatiOS 8.0+
@class AVAudioFormat
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AVAudioChannelLayoutiOS 8.0+
@class AVAudioChannelLayout
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AVAudioBufferiOS 8.0+
@class AVAudioBuffer
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AVAudioPCMBufferiOS 8.0+
@class AVAudioPCMBuffer
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AVAudioCompressedBufferiOS 9.0+
@class AVAudioCompressedBuffer
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AVReadOnlyAudioPCMBufferiOS 27.0+
A read-only, Sendable audio buffer for safe concurrent access.
En
AVAudioCommonFormatiOS 8.0+
@enum AVAudioCommonFormat
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AVAudioTimeiOS 8.0+
@class AVAudioTime

Files and Format Conversion 7

Read and write audio files and convert sample data between formats.

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AVAudioFileiOS 8.0+
@class AVAudioFile
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AVAudioConverteriOS 9.0+
@class AVAudioConverter
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AVAudioConverterPrimeInfo
@struct AVAudioConverterPrimeInfo
En
AVAudioConverterPrimeMethod
@enum AVAudioConverterPrimeMethod
En
AVAudioConverterInputStatusiOS 9.0+
@enum AVAudioConverterInputStatus
En
AVAudioConverterOutputStatusiOS 9.0+
@enum AVAudioConverterOutputStatus
En
AVAudioContentSourceiOS 26.0+
Constants that identify the source of audio content.

Playback and Recording 5

Play sound files and record audio to disk with simple, high-level objects.

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AVAudioPlayeriOS 2.2+
An object that plays audio from a file or in-memory data.
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AVAudioRecorderiOS 3.0+
@class AVAudioRecorder
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AVAudioRecorderDelegateiOS 3.0+
@protocol AVAudioRecorderDelegate
En
AVAudioQuality
Constants that specify the quality level for audio encoding.
En
AVAudioDynamicRangeControlConfiguration
Constants that specify a dynamic range control configuration for audio.

MIDI Sequencing and Instruments 23

Sequence, play, and edit MIDI music tracks, events, and sampler instruments.

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AVAudioSequenceriOS 9.0+
@class AVAudioSequencer
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AVMusicTrackiOS 9.0+
@class AVMusicTrack
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AVMIDIPlayeriOS 8.0+
@class AVMIDIPlayer
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AVAudioUnitMIDIInstrumentiOS 8.0+
Base class for MIDI instruments.
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AVAudioUnitSampleriOS 8.0+
@class AVAudioUnitSampler
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AVMusicEventiOS 16.0+
@class AVMusicEvent
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AVMIDINoteEventiOS 16.0+
@class AVMIDINoteEvent
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AVMIDIChannelEventiOS 16.0+
@class AVMIDIChannelEvent
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AVMIDIControlChangeEventiOS 16.0+
@class AVMIDIControlChangeEvent
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AVMIDIPolyPressureEventiOS 16.0+
@class AVMIDIPolyPressureEvent
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AVMIDIProgramChangeEventiOS 16.0+
@class AVMIDIProgramChangeEvent
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AVMIDIChannelPressureEventiOS 16.0+
@class AVMIDIChannelPressureEvent
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AVMIDIPitchBendEventiOS 16.0+
@class AVMIDIPitchBendEvent
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AVMIDISysexEventiOS 16.0+
@class AVMIDISysexEvent
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AVMIDIMetaEventiOS 16.0+
@class AVMIDIMetaEvent
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AVMusicUserEventiOS 16.0+
@class AVMusicUserEvent
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AVExtendedNoteOnEventiOS 16.0+
@class AVExtendedNoteOnEvent
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AVParameterEventiOS 16.0+
@class AVParameterEvent
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AVAUPresetEventiOS 16.0+
@class AVAUPresetEvent
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AVExtendedTempoEventiOS 16.0+
@class AVExtendedTempoEvent
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AVMusicSequenceLoadOptions
@typedef AVMusicSequenceLoadOptions
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_AVBeatRange
@typedef AVBeatRange
En
AVMusicTrackLoopCountiOS 8.0+
Constants that specify how many times a music track loops.

Audio Session 12

Configure the app's audio behavior, routing, and capabilities with the system.

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AVAudioSessioniOS 3.0+
An object that communicates the app's audio intent and behavior to the system.
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AVAudioApplicationiOS 17.0+
Class containing methods that relate to an application bundle's audio (i.e. a collection of one or more AVAudioSession instances)
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AVAudioSessionDelegate
A protocol for responding to audio session events such as interruptions and route changes.
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AVAudioSessionChannelDescriptioniOS 6.0+
@class AVAudioSessionChannelDescription
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AVAudioSessionDataSourceDescriptioniOS 6.0+
Information about one of potentially multiple data sources associated with a port.
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AVAudioSessionCapabilityiOS 26.0+
Describes whether a specific capability is supported and if that capability is currently enabled
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AVAudioSessionPortDescriptioniOS 6.0+
Information about a port, a physical connector or audio device.
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AVAudioSessionPortExtensionBluetoothMicrophoneiOS 26.0+
An object that describes capabilities of Bluetooth microphone ports.
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AVAudioSessionRouteDescriptioniOS 6.0+
A description of the input and output ports which comprise a route.
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AVAudioSessionSpatialExperiencevisionOS 1.0+
A protocol that describes a spatial audio experience for an audio session.
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AVAudioSessionActivationOptions
@enum AVAudioSessionActivationOptions
St
AVAudioSessionDeactivationOptions
Options for deactivating an AVAudioSession

Voice Processing 2

Configure voice-processing behaviors such as ducking and speech activity detection.

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AVAudioVoiceProcessingOtherAudioDuckingConfigurationiOS 17.0+
@struct AVAudioVoiceProcessingOtherAudioDuckingConfiguration
En
AVAudioVoiceProcessingSpeechActivityEventiOS 17.0+
@enum AVAudioVoiceProcessingSpeechActivityEvent

Speech Synthesis 11

Generate spoken audio from text and provide custom synthesis voices.

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AVSpeechSynthesizeriOS 7.0+
@class AVSpeechSynthesizer
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AVSpeechSynthesizerDelegate
@protocol AVSpeechSynthesizerDelegate
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AVSpeechUtteranceiOS 7.0+
@class AVSpeechUtterance
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AVSpeechSynthesisVoiceiOS 7.0+
@class AVSpeechSynthesisVoice
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AVSpeechSynthesisMarkeriOS 16.0+
An object that marks a position within synthesized speech output.
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AVSpeechSynthesisProviderVoiceiOS 16.0+
@brief The representation of a provided voice that is available for speech synthesis.
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AVSpeechSynthesisProviderRequestiOS 16.0+
An @c AVSpeechSynthesisProviderRequest gets delivered to an @c AVSpeechSynthesisProviderAudioUnit in order to synthesize audio.
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AVSpeechSynthesisProviderAudioUnitiOS 16.0+
An audio unit that a speech synthesis provider extension implements to generate speech.
En
AVSpeechBoundaryiOS 7.0+
Constants that specify whether a speech action takes effect immediately or at a word boundary.
En
AVSpeechSynthesisVoiceQualityiOS 9.0+
Constants that specify the quality level of a speech synthesis voice.
En
AVSpeechSynthesisVoiceGenderiOS 13.0+
Constants that specify the gender associated with a speech synthesis voice.

Protocols 1

Pr
AVAudioPlayerDelegate

Type Aliases 21

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AVAudioConverterInputBlock
@typedef AVAudioConverterInputBlock
Ty
AVAudioEngineManualRenderingBlock
@typedef AVAudioEngineManualRenderingBlock
Ty
AVMIDIEventListBlock
@typedef AVMIDIEventListBlock
Ty
AVAudioIONodeInputBlock
@typedef AVAudioIONodeInputBlock
Ty
AVAudioNodeTapBlock
@typedef AVAudioNodeTapBlock
Ty
AVAudioPlayerNodeCompletionHandler
@typedef AVAudioPlayerNodeCompletionHandler
Ty
AVBeatRange
@typedef AVBeatRange
Ty
AVAudioSequencerUserCallback
Ty
AVMusicEventEnumerationBlock
@typedef AVMusicEventEnumerationBlock
Ty
AVAudioSinkNodeReceiverBlock
@typedef AVAudioSinkNodeReceiverBlock
Ty
AVAudioSourceNodeRenderBlock
@typedef AVAudioSourceNodeRenderBlock
Ty
AVAudioFramePosition
@typedef AVAudioFramePosition
Ty
AVAudioFrameCount
@typedef AVAudioFrameCount
Ty
AVAudioPacketCount
@typedef AVAudioPacketCount
Ty
AVAudioChannelCount
@typedef AVAudioChannelCount
Ty
AVAudioNodeCompletionHandler
@typedef AVAudioNodeCompletionHandler

Show 5 more

Ty
AVAudioNodeBus
@typedef AVAudioNodeBus
Ty
AVMusicTimeStamp
@typedef AVMusicTimeStamp
Ty
AVAudio3DVector
@typedef AVAudio3DVector
Ty
AVMIDIPlayerCompletionHandler
@typedef AVMIDIPlayerCompletionHandler
Ty
AVSpeechSynthesisProviderOutputBlock
@brief A block of information that is relevant to the generation of speech synthesis.

Extends 3

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