import AudioRecorder from 'itslanguage/audio/audio-recorder.js'

public class | source

AudioRecorder

Audio recording component.

Constructor Summary

Public Constructor
public	constructor(options: Object) ITSLanguage AudioRecorder.

Member Summary

Public Members
public	activeRecordingId: *
public	audioContext: *
public	canMediaDevicesGetUserMedia: boolean
public	micInput: *
public	userMediaApproval: boolean

Private Members
private	_emitter: *
private	_recorder: WebAudioRecorder \| MediaRecorder
private	_settings: *
private	_stopwatch: *

Method Summary

Public Methods
public	addEventListener(name: string, handler: Function) Add an event listener.
public	bindStopwatch(tickCb: Function): Stopwatch Bind a stopwatch to sync with the playing and stopping functionality of the recorder.
public	createAudioContext(): AudioContext Get the audio context or create one.
public	getAudioSpecs(): Object Get the recorded audio specifications.
public	hasUserMediaApproval(): boolean Check if the user has already given permission to access the microphone.
public	isRecording(): boolean Check if there is a recording in progress.
public	record(cb: Function, disableDelay: boolean): * Start recording microphone input until stopped.
public	removeAllEventListeners() Turn off all event listeners for this recorder.
public	removeEventListener(name: string, handler: Function) Remove an event listener of the recorder.
public	requestUserMedia(): Promise Request microphone access.
public	startRecordingSession(id: number): number Set a new recording session id.
public	stop(forced: boolean) Stop recording microphone input.
public	streamCallback(chunk: ArrayBuffer) Called when a chunk of audio becomes available.
public	toggleRecording() Toggle audio playback.

Private Methods
private	_getBestRecorder(micInputGain: GainNode): * Get a recorder object that performs audio compression, when available.
private	_recordingCompatibility() Logs browser compatibility for audio recording.
private	_requireGetUserMedia(): boolean Throw an error if the user is not yet logged in.
private	_startUserMedia(stream: MediaStream): * Audio access was granted, start analysing.
private	fireEvent(name: string, args: Object[]) Fire an event.

Public Constructors

public constructor(options: Object) source

ITSLanguage AudioRecorder.

Params:

Name	Type	Attribute	Description
options	Object	nullable: true	Override any of the default settings.

Public Members

public activeRecordingId: * source

public audioContext: * source

public canMediaDevicesGetUserMedia: boolean source

public micInput: * source

public userMediaApproval: boolean source

Private Members

private _emitter: * source

private _recorder: WebAudioRecorder | MediaRecorder source

private _settings: * source

private _stopwatch: * source

Public Methods

public addEventListener(name: string, handler: Function) source

Add an event listener. Listens to events emitted from the recorder.

Params:

Name	Type	Attribute	Description
name	string		Name of the event.
handler	Function		Handler function to add.

public bindStopwatch(tickCb: Function): Stopwatch source

Bind a stopwatch to sync with the playing and stopping functionality of the recorder.

Params:

Name	Type	Attribute	Description
tickCb	Function		Callback to invoke on every tick. A tick occurs once every 100 ms.

Return:

Stopwatch

New Stopwatch object.

Throw:

Error

If _tickCb is null.

public createAudioContext(): AudioContext source

Get the audio context or create one.

Return:

AudioContext

The AudioContext created will be returned

public getAudioSpecs(): Object source

Get the recorded audio specifications.

Return:

Object

Containing audioFormat and audioParameters describing the format.

public hasUserMediaApproval(): boolean source

Check if the user has already given permission to access the microphone.

Return:

boolean

True if user has granted access to the microphone. False otherwise.

public isRecording(): boolean source

Check if there is a recording in progress.

Return:

boolean

True if user is currently recording audio. False` otherwise.

public record(cb: Function, disableDelay: boolean): * source

Start recording microphone input until stopped. By default the actual recording will start a small delay of 100ms. Set disableDelay to true to disable this delay.

Params:

Name	Type	Attribute	Description
cb	Function	nullable: true	The callback that provides a piece of raw audio when it becomes available. It may be used for streaming.
disableDelay	boolean		If set to true it will disable the delay before the actual recording starts.

Return:

Emit:

Event

'recording' With arguments: [recording ID].

public removeAllEventListeners() source

Turn off all event listeners for this recorder.

public removeEventListener(name: string, handler: Function) source

Remove an event listener of the recorder.

Params:

Name	Type	Attribute	Description
name	string		Name of the event.
handler	Function		Handler function to remove.

public requestUserMedia(): Promise source

Request microphone access.

Calling this function may result in thrown exceptions when browser doesn't support provide live audio input.

Return:

Promise

A promise that resolves a MediaStream object. If the user denies permission, or matching media is not available, then the promise is rejected with PermissionDeniedError or NotFoundError respectively.

Throw:

Error

If no live audio input is available or permitted.

public startRecordingSession(id: number): number source

Set a new recording session id.

Params:

Name	Type	Attribute	Description
id	number		When defined, stick this id to the recorded blob.

Return:

number

The id that was given or a unique generated one.

public stop(forced: boolean) source

Stop recording microphone input.

Params:

Name	Type	Attribute	Description
forced	boolean	optional default: false	Set whether to force the microphone to stop recording or let it end normally.

Emit:

Event

'recorded' With arguments: [recording ID, audio Blob, forced].

public streamCallback(chunk: ArrayBuffer) source

Called when a chunk of audio becomes available.

Params:

Name	Type	Attribute	Description
chunk	ArrayBuffer		A chunk of audio (Int16 formatted).

public toggleRecording() source

Toggle audio playback. Switch from playing to paused state and back.

Private Methods

private _getBestRecorder(micInputGain: GainNode): * source

Get a recorder object that performs audio compression, when available.

Using the Media Stream Recording API for recording is the prefered solution. It allows recording compressed audio which makes it quicker to submit. If not available, use a default createScriptProcessor is used.

Params:

Name	Type	Attribute	Description
micInputGain	GainNode		The GainNode to analyze.

Return:

private _recordingCompatibility() source

Logs browser compatibility for audio recording. In case of compatibility issues, an error is thrown.

private _requireGetUserMedia(): boolean source

Throw an error if the user is not yet logged in.

Return:

boolean

True when permission was already granted. False otherwise.

private _startUserMedia(stream: MediaStream): * source

Audio access was granted, start analysing.

Params:

Name	Type	Attribute	Description
stream	MediaStream		Media Stream.

Return:

private fireEvent(name: string, args: Object[]) source

Fire an event.

Params:

Name	Type	Attribute	Description
name	string		Name of the event.
args	Object[]		Arguments.