Voice Processor
iOS API

API Reference for the Voice Processor iOS SDK(CocoaPods).

VoiceProcessor

public class VoiceProcessor { }

The iOS Voice Processor is an asynchronous audio capture library designed for real-time audio processing. Given some specifications, the library delivers frames of raw audio data to the user via listeners.

VoiceProcessor.instance

public static let instance: VoiceProcessor

Singleton instance of VoiceProcessor.

VoiceProcessor.isRecording

public var isRecording: Bool

A boolean value indicating if the VoiceProcessor is currently recording audio.

VoiceProcessor.frameLength

public var frameLength: UInt32?

The number of audio samples per frame. Set when calling the start() method.

VoiceProcessor.sampleRate

public var sampleRate: UInt32?

The sample rate for audio recording, set when calling the start() method.

VoiceProcessor.numFrameListeners

public var numFrameListeners: Int

The number of registered VoiceProcessorFrameListeners.

VoiceProcessor.numErrorListeners

public var numErrorListeners: Int

The number of registered VoiceProcessorErrorListeners.

VoiceProcessor.hasRecordAudioPermission

public static var hasRecordAudioPermission: Bool

Indicates whether the app has permission to record audio.

Returns

• Bool: True if the app has permission to record audio, false otherwise.

VoiceProcessor.requestRecordAudioPermission()

public static func requestRecordAudioPermission(_ response: @escaping (Bool) -> Void)

Requests permission to record audio from the user.

Parameters

• response @escaping (Bool) -> Void : A closure to handle the user's response to the permission request.

VoiceProcessor.addFrameListener()

public func addFrameListener(_ listener: VoiceProcessorFrameListener)

Adds a listener to receive audio frames.

Parameters

• listener VoiceProcessorFrameListener: The VoiceProcessorFrameListener to be added as a frame listener.

VoiceProcessor.addFrameListeners()

public func addFrameListeners(_ listeners: [VoiceProcessorFrameListener])

Adds multiple frame listeners to receive audio frames.

Parameters

• listeners [VoiceProcessorFrameListener] : An array of VoiceProcessorFrameListener to be added as frame listeners.

VoiceProcessor.removeFrameListener()

public func removeFrameListener(_ listener: VoiceProcessorFrameListener)

Removes a previously added frame listener.

Parameters

• listener VoiceProcessorFrameListener : The VoiceProcessorFrameListener to be removed.

VoiceProcessor.removeFrameListeners()

public func removeFrameListeners(_ listeners: [VoiceProcessorFrameListener])

Removes previously added multiple frame listeners.

Parameters

• listeners [VoiceProcessorFrameListener] : An array of VoiceProcessorFrameListener to be removed.

VoiceProcessor.clearFrameListeners()

public func clearFrameListeners()

Clears all currently registered frame listeners.

VoiceProcessor.addErrorListener()

public func addErrorListener(_ listener: VoiceProcessorErrorListener)

Adds an error listener.

Parameters

• listener VoiceProcessorErrorListener : The VoiceProcessorErrorListener to be added as an error listener.

VoiceProcessor.removeErrorListener()

public func removeErrorListener(_ listener: VoiceProcessorErrorListener)

Removes a previously added error listener.

Parameters

• listener VoiceProcessorErrorListener : The VoiceProcessorErrorListener to be removed.

VoiceProcessor.clearErrorListeners()

public func clearErrorListeners()

Clears all error listeners.

VoiceProcessor.start()

public func start(frameLength: UInt32, sampleRate: UInt32) throws

Starts audio recording with the specified audio properties.

Parameters

• frameLength UInt32 : The length of each audio frame, in number of samples.
• sampleRate UInt32 : The sample rate to record audio at, in Hz.

Throws

• VoiceProcessorError : An error if there is an issue starting the audio recording.

VoiceProcessor.stop()

public func stop() throws

Stops audio recording and releases audio resources.

Throws

• VoiceProcessorError: An error if there is an issue stopping the audio recording.

VoiceProcessorError

public class VoiceProcessorError: LocalizedError { }

Error thrown if an error occurs within the VoiceProcessor.

public class VoiceProcessorArgumentError    : VoiceProcessorError {}
public class VoiceProcessorReadError        : VoiceProcessorError {}
public class VoiceProcessorRuntimeError     : VoiceProcessorError {}

VoiceProcessorErrorCallback

public typealias VoiceProcessorErrorCallback = (VoiceProcessorError) -> Void

Typealias for the callback function that handles errors that are emitted from VoiceProcessor.

VoiceProcessorErrorListener

public class VoiceProcessorErrorListener { }

Listener class for receiving errors from VoiceProcessor.

VoiceProcessorErrorListener.init()

public init(_ callback: @escaping VoiceProcessorErrorCallback)

Initializes a new VoiceProcessorErrorListener.

Parameters

• callback @escaping VoiceProcessorErrorCallback : The callback function to be called when a VoiceProcessorError occurs.

VoiceProcessorErrorListener.onError()

public func onError(_ error: VoiceProcessorError)

Function called when a VoiceProcessorError occurs.

Parameters

• error VoiceProcessorError : Error.

VoiceProcessorFrameCallback

public typealias VoiceProcessorFrameCallback = ([Int16]) -> Void

Typealias for the callback function that handles frames of audio data.

VoiceProcessorFrameListener

public class VoiceProcessorFrameListener { }

Listener class for receiving audio frames from VoiceProcessor.

VoiceProcessorFrameListener.init()

public init(_ callback: @escaping VoiceProcessorFrameCallback)

Initializes a new VoiceProcessorFrameListener.

Parameters

• callback @escaping VoiceProcessorFrameCallback : The callback function to be called when an audio frame is received.

VoiceProcessorFrameListener.onFrame()

public func onFrame(_ frame: [Int16])

Function called when a frame of audio is received.

Parameters

• frame [Int16] : Frame of audio.