import MediaElement from 'wavesurfer.js/src/mediaelement.js'

public class | source

MediaElement

Extends:

util.Observer → WebAudio → MediaElement

Direct Subclass:

MediaElementWebAudio

MediaElement backend

Constructor Summary

Public Constructor
public	constructor(params: WavesurferParams) Construct the backend

Member Summary

Public Members
public	destroyed: boolean

Method Summary

Public Methods
public	createTimer() Create a timer to provide a more precise `audioprocess` event.
public	destroy() This is called when wavesurfer is destroyed
public	getCurrentTime(): number Returns the current time in seconds relative to the audio-clip's duration.
public	getDuration(): number Used by `wavesurfer.getDuration()`
public	getPeaks(length: number, first: number, last: number): number[] \| Number<Array[]> Compute the max and min value of the waveform when broken into <length> subranges.
public	getPlaybackRate(): number Get the audio source playback rate.
public	getPlayedPercents(): number Get the position from 0 to 1
public	getVolume(): number Get the current volume
public	init() Initialise the backend, called in `wavesurfer.createBackend()`
public	isPaused(): boolean Used by `wavesurfer.isPlaying()` and `wavesurfer.playPause()`
public	load(url: string, container: HTMLElement, peaks: number[] \| Number<Array[]>, preload: string) Create media element with url as its source, and append to container element.
public	loadElt(elt: HTMLMediaElement, peaks: number[] \| Number<Array[]>) Load existing media element.
public	pause(): Promise Pauses the loaded audio.
public	play(start: number, end: number): Promise Plays the loaded audio region.
public	seekTo(start: number) Used by `wavesurfer.seekTo()`
public	setMute(muted: boolean) Enable or disable muted audio	since 4.0.0
public	setPlayEnd(end: number) Set the play end
public	setPlaybackRate(value: number) Set the audio source playback rate.
public	setSinkId(deviceId: string): Promise Set the sink id for the media player
public	setVolume(value: number) Set the audio volume

Inherited Summary

From class WebAudio
public	ac: * ac: Audio Context instance
public	analyser: * analyser: provides audio analysis information
public	audioContext: * audioContext: allows to process audio with WebAudio API
public	destroyed: boolean Boolean indicating if the backend was destroyed.
public	gainNode: * gainNode: allows to control audio volume
public	scriptNode: * scriptNode: allows processing audio
public	createAnalyserNode() Create analyser node to perform audio analysis
public	createScriptNode() Create ScriptProcessorNode to process audio
public	createVolumeNode() Create the gain node needed to control the playback volume.
public	destroy() This is called when wavesurfer is destroyed
public	destroyWebAudio() Destroy all references with WebAudio, disconnecting audio nodes and closing Audio Context
public	getAudioContext(): AudioContext Get the audio context used by this backend or create one
public	getCurrentTime(): number Returns the current time in seconds relative to the audio-clip's duration.
public	getDuration(): number Used by `wavesurfer.getDuration()`
public	getOfflineAudioContext(sampleRate: number): OfflineAudioContext Get the offline audio context used by this backend or create one
public	getPeaks(length: number, first: number, last: number): number[] \| Number<Array[]> Compute the max and min value of the waveform when broken into <length> subranges.
public	getPlaybackRate(): number Returns the current playback rate.
public	getPlayedPercents(): number Get the position from 0 to 1
public	getPlayedTime(): number Get the playback position in seconds
public	getVolume(): number Get the current volume
public	init() Initialise the backend, called in `wavesurfer.createBackend()`
public	isPaused(): boolean Used by `wavesurfer.isPlaying()` and `wavesurfer.playPause()`
public	load(buffer: Object) Loaded a decoded audio buffer
public	pause() Pauses the loaded audio.
public	play(start: number, end: number) Plays the loaded audio region.
public	seekTo(start: number, end: number): {start: number, end: number} Used by `wavesurfer.seekTo()`
public	setFilter(filters: ...AudioNode) Unpacked `setFilters()`
public	setFilters(filters: AudioNode[]) Insert custom Web Audio nodes into the graph
public	setLength(length: number) Set the rendered length (different from the length of the audio)
public	setPeaks(peaks: number[] \| Number<Array[]>, duration: number) Set pre-decoded peaks
public	setPlayEnd(end: number) Set a point in seconds for playback to stop at.	version 3.3.0
public	setPlaybackRate(value: number) Set the audio source playback rate.
public	setSinkId(deviceId: string): Promise Set the sink id for the media player
public	setVolume(value: number) Set the audio volume
public	supportsWebAudio(): boolean Does the browser support this backend

Public Constructors

public constructor(params: WavesurferParams) source

Construct the backend

Override:

WebAudio#constructor

Params:

Name	Type	Attribute	Description
params	WavesurferParams		Wavesurfer parameters

Public Members

public destroyed: boolean source

Boolean indicating if the backend was destroyed.

Override:

WebAudio#destroyed

Public Methods

public createTimer() source

Create a timer to provide a more precise audioprocess event.

public destroy() source

This is called when wavesurfer is destroyed

Override:

WebAudio#destroy

public getCurrentTime(): number source

Returns the current time in seconds relative to the audio-clip's duration.

Override:

WebAudio#getCurrentTime

Return:

number

Current time

public getDuration(): number source

Used by wavesurfer.getDuration()

Override:

WebAudio#getDuration

Return:

number

Duration

public getPeaks(length: number, first: number, last: number): number[] | Number<Array[]> source

Compute the max and min value of the waveform when broken into

<length> subranges.

Override:

WebAudio#getPeaks

Params:

Name	Type	Attribute	Description
length	number		How many subranges to break the waveform into.
first	number		First sample in the required range.
last	number		Last sample in the required range.

Return:

number[] | Number<Array[]>

Array of 2*<length> peaks or array of arrays of peaks consisting of (max, min) values for each subrange.

public getPlaybackRate(): number source

Get the audio source playback rate.

Override:

WebAudio#getPlaybackRate

Return:

number

Playback rate

public getPlayedPercents(): number source

Get the position from 0 to 1

Override:

WebAudio#getPlayedPercents

Return:

number

Current position

public getVolume(): number source

Get the current volume

Override:

WebAudio#getVolume

Return:

number

value A floating point value between 0 and 1.

public init() source

Initialise the backend, called in wavesurfer.createBackend()

Override:

WebAudio#init

public isPaused(): boolean source

Used by wavesurfer.isPlaying() and wavesurfer.playPause()

Override:

WebAudio#isPaused

Return:

boolean

Media paused or not

public load(url: string, container: HTMLElement, peaks: number[] | Number<Array[]>, preload: string) source

Create media element with url as its source, and append to container element.

Override:

WebAudio#load

Params:

Name	Type	Attribute	Description
url	string		Path to media file
container	HTMLElement		HTML element
peaks	number[] \| Number<Array[]>		Array of peak data
preload	string		HTML 5 preload attribute value

Throw:

*	Will throw an error if the `url` argument is not a valid media element.

public loadElt(elt: HTMLMediaElement, peaks: number[] | Number<Array[]>) source

Load existing media element.

Params:

Name	Type	Attribute	Description
elt	HTMLMediaElement		HTML5 Audio or Video element
peaks	number[] \| Number<Array[]>		Array of peak data

public pause(): Promise source

Pauses the loaded audio.

Override:

WebAudio#pause

Return:

Promise

Result

Emit:

*	MediaElement#pause

public play(start: number, end: number): Promise source

Plays the loaded audio region.

Override:

WebAudio#play

Params:

Name	Type	Attribute	Description
start	number		Start offset in seconds, relative to the beginning of a clip.
end	number		When to stop, relative to the beginning of a clip.

Return:

Promise

Result

Emit:

*	MediaElement#play

public seekTo(start: number) source

Used by wavesurfer.seekTo()

Override:

WebAudio#seekTo

Params:

Name	Type	Attribute	Description
start	number		Position to start at in seconds

public setMute(muted: boolean) since 4.0.0 source

Enable or disable muted audio

Params:

Name	Type	Attribute	Description
muted	boolean		Specify `true` to mute audio.

public setPlayEnd(end: number) source

Set the play end

Override:

WebAudio#setPlayEnd

Params:

Name	Type	Attribute	Description
end	number		Where to end

public setPlaybackRate(value: number) source

Set the audio source playback rate.

Override:

WebAudio#setPlaybackRate

Params:

Name	Type	Attribute	Description
value	number		Playback rate

public setSinkId(deviceId: string): Promise source

Set the sink id for the media player

Override:

WebAudio#setSinkId

Params:

Name	Type	Attribute	Description
deviceId	string		String value representing audio device id.

Return:

Promise

A Promise that resolves to undefined when there are no errors.

public setVolume(value: number) source

Set the audio volume

Override:

WebAudio#setVolume

Params:

Name	Type	Attribute	Description
value	number		A floating point value between 0 and 1.