import MediaElementWebAudio from 'wavesurfer.js/src/mediaelement-webaudio.js'

public class | since 3.2.0 | source

MediaElementWebAudio

Extends:

util.Observer → WebAudio → MediaElement → MediaElementWebAudio

MediaElementWebAudio backend: load audio via an HTML5 audio tag, but playback with the WebAudio API. The advantage here is that the html5 <audio> tag can perform range requests on the server and not buffer the entire file in one request, and you still get the filtering and scripting functionality of the webaudio API. Note that in order to use range requests and prevent buffering, you must provide peak data.

Constructor Summary

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

Method Summary

Public Methods
public	createMediaElementSource(mediaElement: HTMLMediaElement) Create MediaElementSource node	since 3.2.0
public	destroy() This is called when wavesurfer is destroyed
public	init() Initialise the backend, called in `wavesurfer.createBackend()`
public	play(start: , end: ): *

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

From class MediaElement
public	destroyed: boolean
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

Public Constructors

public constructor(params: WavesurferParams) source

Construct the backend

Override:

MediaElement#constructor

Params:

Name	Type	Attribute	Description
params	WavesurferParams		Wavesurfer parameters

Public Methods

public createMediaElementSource(mediaElement: HTMLMediaElement) since 3.2.0 source

Create MediaElementSource node

Params:

Name	Type	Attribute	Description
mediaElement	HTMLMediaElement		HTML5 Audio to load

public destroy() source

This is called when wavesurfer is destroyed

Override:

MediaElement#destroy

public init() source

Initialise the backend, called in wavesurfer.createBackend()

Override:

MediaElement#init

public play(start: , end: ): * source

Plays the loaded audio region.

Override:

MediaElement#play

Params:

Name	Type	Attribute	Description
start	*
end	*

MediaElementWebAudio

Extends:

Constructor Summary

Method Summary

Inherited Summary

Public Constructors

public constructor(params: WavesurferParams) source

Override:

Params:

Public Methods

public createMediaElementSource(mediaElement: HTMLMediaElement) since 3.2.0 source

Params:

public destroy() source

Override:

public init() source

Override:

public play(start: *, end: *): * source

Override:

Params:

Return:

public play(start: , end: ): * source