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edlp_d8/libraries/wavesurfer/src/wavesurfer.js
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JavaScript
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import * as util from './util';
import MultiCanvas from './drawer.multicanvas';
import WebAudio from './webaudio';
import MediaElement from './mediaelement';
import PeakCache from './peakcache';
/*
* This work is licensed under a BSD-3-Clause License.
*/
/** @external {HTMLElement} https://developer.mozilla.org/en/docs/Web/API/HTMLElement */
/** @external {OfflineAudioContext} https://developer.mozilla.org/en-US/docs/Web/API/OfflineAudioContext */
/** @external {File} https://developer.mozilla.org/en-US/docs/Web/API/File */
/** @external {Blob} https://developer.mozilla.org/en-US/docs/Web/API/Blob */
/** @external {CanvasRenderingContext2D} https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D */
/** @external {MediaStreamConstraints} https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamConstraints */
/** @external {AudioNode} https://developer.mozilla.org/de/docs/Web/API/AudioNode */
/**
* @typedef {Object} WavesurferParams
* @property {AudioContext} audioContext=null Use your own previously
* initialized AudioContext or leave blank.
* @property {number} audioRate=1 Speed at which to play audio. Lower number is
* slower.
* @property {boolean} autoCenter=true If a scrollbar is present, center the
* waveform around the progress
* @property {string} backend='WebAudio' `'WebAudio'|'MediaElement'` In most cases
* you don't have to set this manually. MediaElement is a fallback for
* unsupported browsers.
* @property {number} barHeight=1 The height of the wave
* @property {boolean} closeAudioContext=false Close and nullify all audio
* contexts when the destroy method is called.
* @property {!string|HTMLElement} container CSS selector or HTML element where
* the waveform should be drawn. This is the only required parameter.
* @property {string} cursorColor='#333' The fill color of the cursor indicating
* the playhead position.
* @property {number} cursorWidth=1 Measured in pixels.
* @property {boolean} fillParent=true Whether to fill the entire container or
* draw only according to `minPxPerSec`.
* @property {boolean} forceDecode=false Force decoding of audio using web audio
* when zooming to get a more detailed waveform.
* @property {number} height=128 The height of the waveform. Measured in
* pixels.
* @property {boolean} hideScrollbar=false Whether to hide the horizontal
* scrollbar when one would normally be shown.
* @property {boolean} interact=true Whether the mouse interaction will be
* enabled at initialization. You can switch this parameter at any time later
* on.
* @property {boolean} loopSelection=true (Use with regions plugin) Enable
* looping of selected regions
* @property {number} maxCanvasWidth=4000 Maximum width of a single canvas in
* pixels, excluding a small overlap (2 * `pixelRatio`, rounded up to the next
* even integer). If the waveform is longer than this value, additional canvases
* will be used to render the waveform, which is useful for very large waveforms
* that may be too wide for browsers to draw on a single canvas.
* @property {boolean} mediaControls=false (Use with backend `MediaElement`)
* this enables the native controls for the media element
* @property {string} mediaType='audio' (Use with backend `MediaElement`)
* `'audio'|'video'`
* @property {number} minPxPerSec=20 Minimum number of pixels per second of
* audio.
* @property {boolean} normalize=false If true, normalize by the maximum peak
* instead of 1.0.
* @property {boolean} partialRender=false Use the PeakCache to improve
* rendering speed of large waveforms
* @property {number} pixelRatio=window.devicePixelRatio The pixel ratio used to
* calculate display
* @property {PluginDefinition[]} plugins=[] An array of plugin definitions to
* register during instantiation, they will be directly initialised unless they
* are added with the `deferInit` property set to true.
* @property {string} progressColor='#555' The fill color of the part of the
* waveform behind the cursor.
* @property {Object} renderer=MultiCanvas Can be used to inject a custom
* renderer.
* @property {boolean|number} responsive=false If set to `true` resize the
* waveform, when the window is resized. This is debounced with a `100ms`
* timeout by default. If this parameter is a number it represents that timeout.
* @property {boolean} scrollParent=false Whether to scroll the container with a
* lengthy waveform. Otherwise the waveform is shrunk to the container width
* (see fillParent).
* @property {number} skipLength=2 Number of seconds to skip with the
* skipForward() and skipBackward() methods.
* @property {boolean} splitChannels=false Render with seperate waveforms for
* the channels of the audio
* @property {string} waveColor='#999' The fill color of the waveform after the
* cursor.
*/
/**
* @typedef {Object} PluginDefinition
* @desc The Object used to describe a plugin
* @example wavesurfer.addPlugin(pluginDefinition);
* @property {string} name The name of the plugin, the plugin instance will be
* added as a property to the wavesurfer instance under this name
* @property {?Object} staticProps The properties that should be added to the
* wavesurfer instance as static properties
* @property {?boolean} deferInit Don't initialise plugin
* automatically
* @property {Object} params={} The plugin parameters, they are the first parameter
* passed to the plugin class constructor function
* @property {PluginClass} instance The plugin instance factory, is called with
* the dependency specified in extends. Returns the plugin class.
*/
/**
* @interface PluginClass
*
* @desc This is the interface which is implemented by all plugin classes. Note
* that this only turns into an observer after being passed through
* `wavesurfer.addPlugin`.
*
* @extends {Observer}
*/
class PluginClass {
/**
* Plugin definition factory
*
* This function must be used to create a plugin definition which can be
* used by wavesurfer to correctly instantiate the plugin.
*
* @param {Object} params={} The plugin params (specific to the plugin)
* @return {PluginDefinition} an object representing the plugin
*/
create(params) {}
/**
* Construct the plugin
*
* @param {Object} ws The wavesurfer instance
* @param {Object} params={} The plugin params (specific to the plugin)
*/
constructor(ws, params) {}
/**
* Initialise the plugin
*
* Start doing something. This is called by
* `wavesurfer.initPlugin(pluginName)`
*/
init() {}
/**
* Destroy the plugin instance
*
* Stop doing something. This is called by
* `wavesurfer.destroyPlugin(pluginName)`
*/
destroy() {}
}
/**
* WaveSurfer core library class
*
* @extends {Observer}
* @example
* const params = {
* container: '#waveform',
* waveColor: 'violet',
* progressColor: 'purple'
* };
*
* // initialise like this
* const wavesurfer = WaveSurfer.create(params);
*
* // or like this ...
* const wavesurfer = new WaveSurfer(params);
* wavesurfer.init();
*
* // load audio file
* wavesurfer.load('example/media/demo.wav');
*/
export default class WaveSurfer extends util.Observer {
/** @private */
defaultParams = {
audioContext : null,
audioRate : 1,
autoCenter : true,
backend : 'WebAudio',
barHeight : 1,
container : null,
cursorColor : '#333',
cursorWidth : 1,
dragSelection : true,
fillParent : true,
forceDecode : false,
height : 128,
hideScrollbar : false,
interact : true,
loopSelection : true,
maxCanvasWidth: 4000,
mediaContainer: null,
mediaControls : false,
mediaType : 'audio',
minPxPerSec : 20,
normalize : false,
partialRender : false,
pixelRatio : window.devicePixelRatio || screen.deviceXDPI / screen.logicalXDPI,
plugins : [],
progressColor : '#555',
renderer : MultiCanvas,
responsive : false,
scrollParent : false,
skipLength : 2,
splitChannels : false,
waveColor : '#999'
}
/** @private */
backends = {
MediaElement,
WebAudio
}
/**
* Instantiate this class, call its `init` function and returns it
*
* @param {WavesurferParams} params
* @return {Object} WaveSurfer instance
* @example const wavesurfer = WaveSurfer.create(params);
*/
static create(params) {
const wavesurfer = new WaveSurfer(params);
return wavesurfer.init();
}
/**
* Functions in the `util` property are available as a prototype property to
* all instances
*
* @type {Object}
* @example
* const wavesurfer = WaveSurfer.create(params);
* wavesurfer.util.style(myElement, { background: 'blue' });
*/
util = util
/**
* Functions in the `util` property are available as a static property of the
* WaveSurfer class
*
* @type {Object}
* @example
* WaveSurfer.util.style(myElement, { background: 'blue' });
*/
static util = util
/**
* Initialise wavesurfer instance
*
* @param {WavesurferParams} params Instantiation options for wavesurfer
* @example
* const wavesurfer = new WaveSurfer(params);
* @returns {this}
*/
constructor(params) {
super();
/**
* Extract relevant parameters (or defaults)
* @private
*/
this.params = util.extend({}, this.defaultParams, params);
/** @private */
this.container = 'string' == typeof params.container ?
document.querySelector(this.params.container) :
this.params.container;
if (!this.container) {
throw new Error('Container element not found');
}
if (this.params.mediaContainer == null) {
/** @private */
this.mediaContainer = this.container;
} else if (typeof this.params.mediaContainer == 'string') {
/** @private */
this.mediaContainer = document.querySelector(this.params.mediaContainer);
} else {
/** @private */
this.mediaContainer = this.params.mediaContainer;
}
if (!this.mediaContainer) {
throw new Error('Media Container element not found');
}
if (this.params.maxCanvasWidth <= 1) {
throw new Error('maxCanvasWidth must be greater than 1');
} else if (this.params.maxCanvasWidth % 2 == 1) {
throw new Error('maxCanvasWidth must be an even number');
}
/**
* @private Used to save the current volume when muting so we can
* restore once unmuted
* @type {number}
*/
this.savedVolume = 0;
/**
* @private The current muted state
* @type {boolean}
*/
this.isMuted = false;
/**
* @private Will hold a list of event descriptors that need to be
* cancelled on subsequent loads of audio
* @type {Object[]}
*/
this.tmpEvents = [];
/**
* @private Holds any running audio downloads
* @type {Observer}
*/
this.currentAjax = null;
/** @private */
this.arraybuffer = null;
/** @private */
this.drawer = null;
/** @private */
this.backend = null;
/** @private */
this.peakCache = null;
// cache constructor objects
if (typeof this.params.renderer !== 'function') {
throw new Error('Renderer parameter is invalid');
}
/**
* @private The uninitialised Drawer class
*/
this.Drawer = this.params.renderer;
/**
* @private The uninitialised Backend class
*/
this.Backend = this.backends[this.params.backend];
/**
* @private map of plugin names that are currently initialised
*/
this.initialisedPluginList = {};
/** @private */
this.isDestroyed = false;
/** @private */
this.isReady = false;
// responsive debounced event listener. If this.params.responsive is not
// set, this is never called. Use 100ms or this.params.responsive as
// timeout for the debounce function.
let prevWidth = 0;
this._onResize = util.debounce(() => {
if (prevWidth != this.drawer.wrapper.clientWidth) {
prevWidth = this.drawer.wrapper.clientWidth;
this.drawBuffer();
}
}, typeof this.params.responsive === 'number' ? this.params.responsive : 100);
return this;
}
/**
* Initialise the wave
*
* @example
* var wavesurfer = new WaveSurfer(params);
* wavesurfer.init();
* @return {this}
*/
init() {
this.registerPlugins(this.params.plugins);
this.createDrawer();
this.createBackend();
this.createPeakCache();
return this;
}
/**
* Add and initialise array of plugins (if `plugin.deferInit` is falsey),
* this function is called in the init function of wavesurfer
*
* @param {PluginDefinition[]} plugins An array of plugin definitions
* @emits {WaveSurfer#plugins-registered} Called with the array of plugin definitions
* @return {this}
*/
registerPlugins(plugins) {
// first instantiate all the plugins
plugins.forEach(plugin => this.addPlugin(plugin));
// now run the init functions
plugins.forEach(plugin => {
// call init function of the plugin if deferInit is falsey
// in that case you would manually use initPlugins()
if (!plugin.deferInit) {
this.initPlugin(plugin.name);
}
});
this.fireEvent('plugins-registered', plugins);
return this;
}
/**
* Add a plugin object to wavesurfer
*
* @param {PluginDefinition} plugin A plugin definition
* @emits {WaveSurfer#plugin-added} Called with the name of the plugin that was added
* @example wavesurfer.addPlugin(WaveSurfer.minimap());
* @return {this}
*/
addPlugin(plugin) {
if (!plugin.name) {
throw new Error('Plugin does not have a name!');
}
if (!plugin.instance) {
throw new Error(`Plugin ${plugin.name} does not have an instance property!`);
}
// staticProps properties are applied to wavesurfer instance
if (plugin.staticProps) {
Object.keys(plugin.staticProps).forEach(pluginStaticProp => {
/**
* Properties defined in a plugin definition's `staticProps` property are added as
* staticProps properties of the WaveSurfer instance
*/
this[pluginStaticProp] = plugin.staticProps[pluginStaticProp];
});
}
const Instance = plugin.instance;
// turn the plugin instance into an observer
const observerPrototypeKeys = Object.getOwnPropertyNames(util.Observer.prototype);
observerPrototypeKeys.forEach(key => {
Instance.prototype[key] = util.Observer.prototype[key];
});
/**
* Instantiated plugin classes are added as a property of the wavesurfer
* instance
* @type {Object}
*/
this[plugin.name] = new Instance(plugin.params || {}, this);
this.fireEvent('plugin-added', plugin.name);
return this;
}
/**
* Initialise a plugin
*
* @param {string} name A plugin name
* @emits WaveSurfer#plugin-initialised
* @example wavesurfer.initPlugin('minimap');
* @return {this}
*/
initPlugin(name) {
if (!this[name]) {
throw new Error(`Plugin ${name} has not been added yet!`);
}
if (this.initialisedPluginList[name]) {
// destroy any already initialised plugins
this.destroyPlugin(name);
}
this[name].init();
this.initialisedPluginList[name] = true;
this.fireEvent('plugin-initialised', name);
return this;
}
/**
* Destroy a plugin
*
* @param {string} name A plugin name
* @emits WaveSurfer#plugin-destroyed
* @example wavesurfer.destroyPlugin('minimap');
* @returns {this}
*/
destroyPlugin(name) {
if (!this[name]) {
throw new Error(`Plugin ${name} has not been added yet and cannot be destroyed!`);
}
if (!this.initialisedPluginList[name]) {
throw new Error(`Plugin ${name} is not active and cannot be destroyed!`);
}
if (typeof this[name].destroy !== 'function') {
throw new Error(`Plugin ${name} does not have a destroy function!`);
}
this[name].destroy();
delete this.initialisedPluginList[name];
this.fireEvent('plugin-destroyed', name);
return this;
}
/**
* Destroy all initialised plugins. Convenience function to use when
* wavesurfer is removed
*
* @private
*/
destroyAllPlugins() {
Object.keys(this.initialisedPluginList).forEach(name => this.destroyPlugin(name));
}
/**
* Create the drawer and draw the waveform
*
* @private
* @emits WaveSurfer#drawer-created
*/
createDrawer() {
this.drawer = new this.Drawer(this.container, this.params);
this.drawer.init();
this.fireEvent('drawer-created', this.drawer);
if (this.params.responsive) {
window.addEventListener('resize', this._onResize, true);
}
this.drawer.on('redraw', () => {
this.drawBuffer();
this.drawer.progress(this.backend.getPlayedPercents());
});
// Click-to-seek
this.drawer.on('click', (e, progress) => {
setTimeout(() => this.seekTo(progress), 0);
});
// Relay the scroll event from the drawer
this.drawer.on('scroll', e => {
if (this.params.partialRender) {
this.drawBuffer();
}
this.fireEvent('scroll', e);
});
}
/**
* Create the backend
*
* @private
* @emits WaveSurfer#backend-created
*/
createBackend() {
if (this.backend) {
this.backend.destroy();
}
// Back compat
if (this.params.backend == 'AudioElement') {
this.params.backend = 'MediaElement';
}
if (this.params.backend == 'WebAudio' && !this.Backend.prototype.supportsWebAudio.call(null)) {
this.params.backend = 'MediaElement';
}
this.backend = new this.Backend(this.params);
this.backend.init();
this.fireEvent('backend-created', this.backend);
this.backend.on('finish', () => this.fireEvent('finish'));
this.backend.on('play', () => this.fireEvent('play'));
this.backend.on('pause', () => this.fireEvent('pause'));
this.backend.on('audioprocess', time => {
this.drawer.progress(this.backend.getPlayedPercents());
this.fireEvent('audioprocess', time);
});
}
/**
* Create the peak cache
*
* @private
*/
createPeakCache() {
if (this.params.partialRender) {
this.peakCache = new PeakCache();
}
}
/**
* Get the duration of the audio clip
*
* @example const duration = wavesurfer.getDuration();
* @return {number} Duration in seconds
*/
getDuration() {
return this.backend.getDuration();
}
/**
* Get the current playback position
*
* @example const currentTime = wavesurfer.getCurrentTime();
* @return {number} Playback position in seconds
*/
getCurrentTime() {
return this.backend.getCurrentTime();
}
/**
* Set the current play time in seconds.
*
* @param {Number} seconds A positive number in seconds. E.g. 10 means 10
* seconds, 60 means 1 minute
*/
setCurrentTime(seconds) {
if (this.getDuration() >= seconds) {
this.seekTo(1);
} else {
this.seekTo(seconds/this.getDuration());
}
}
/**
* Starts playback from the current position. Optional start and end
* measured in seconds can be used to set the range of audio to play.
*
* @param {?number} start Position to start at
* @param {?number} end Position to end at
* @emits WaveSurfer#interaction
* @example
* // play from second 1 to 5
* wavesurfer.play(1, 5);
*/
play(start, end) {
this.fireEvent('interaction', () => this.play(start, end));
this.backend.play(start, end);
}
/**
* Stops playback
*
* @example wavesurfer.pause();
*/
pause() {
this.backend.isPaused() || this.backend.pause();
}
/**
* Toggle playback
*
* @example wavesurfer.playPause();
*/
playPause() {
this.backend.isPaused() ? this.play() : this.pause();
}
/**
* Get the current playback state
*
* @example const isPlaying = wavesurfer.isPlaying();
* @return {boolean} False if paused, true if playing
*/
isPlaying() {
return !this.backend.isPaused();
}
/**
* Skip backward
*
* @param {?number} seconds Amount to skip back, if not specified `skipLength`
* is used
* @example wavesurfer.skipBackward();
*/
skipBackward(seconds) {
this.skip(-seconds || -this.params.skipLength);
}
/**
* Skip forward
*
* @param {?number} seconds Amount to skip back, if not specified `skipLength`
* is used
* @example wavesurfer.skipForward();
*/
skipForward(seconds) {
this.skip(seconds || this.params.skipLength);
}
/**
* Skip a number of seconds from the current position (use a negative value
* to go backwards).
*
* @param {number} offset Amount to skip back or forwards
* @example
* // go back 2 seconds
* wavesurfer.skip(-2);
*/
skip(offset) {
const duration = this.getDuration() || 1;
let position = this.getCurrentTime() || 0;
position = Math.max(0, Math.min(duration, position + (offset || 0)));
this.seekAndCenter(position / duration);
}
/**
* Seeks to a position and centers the view
*
* @param {number} progress Between 0 (=beginning) and 1 (=end)
* @example
* // seek and go to the middle of the audio
* wavesurfer.seekTo(0.5);
*/
seekAndCenter(progress) {
this.seekTo(progress);
this.drawer.recenter(progress);
}
/**
* Seeks to a position
*
* @param {number} progress Between 0 (=beginning) and 1 (=end)
* @emits WaveSurfer#interaction
* @emits WaveSurfer#seek
* @example
* // seek to the middle of the audio
* wavesurfer.seekTo(0.5);
*/
seekTo(progress) {
this.fireEvent('interaction', () => this.seekTo(progress));
const paused = this.backend.isPaused();
// avoid draw wrong position while playing backward seeking
if (!paused) {
this.backend.pause();
}
// avoid small scrolls while paused seeking
const oldScrollParent = this.params.scrollParent;
this.params.scrollParent = false;
this.backend.seekTo(progress * this.getDuration());
this.drawer.progress(this.backend.getPlayedPercents());
if (!paused) {
this.backend.play();
}
this.params.scrollParent = oldScrollParent;
this.fireEvent('seek', progress);
}
/**
* Stops and goes to the beginning.
*
* @example wavesurfer.stop();
*/
stop() {
this.pause();
this.seekTo(0);
this.drawer.progress(0);
}
/**
* Set the playback volume.
*
* @param {number} newVolume A value between 0 and 1, 0 being no
* volume and 1 being full volume.
*/
setVolume(newVolume) {
this.backend.setVolume(newVolume);
}
/**
* Get the playback volume.
*
* @return {number} A value between 0 and 1, 0 being no
* volume and 1 being full volume.
*/
getVolume () {
return this.backend.getVolume();
}
/**
* Set the playback rate.
*
* @param {number} rate A positive number. E.g. 0.5 means half the normal
* speed, 2 means double speed and so on.
* @example wavesurfer.setPlaybackRate(2);
*/
setPlaybackRate(rate) {
this.backend.setPlaybackRate(rate);
}
/**
* Get the playback rate.
*
* @return {number}
*/
getPlaybackRate() {
return this.backend.getPlaybackRate();
}
/**
* Toggle the volume on and off. It not currenly muted it will save the
* current volume value and turn the volume off. If currently muted then it
* will restore the volume to the saved value, and then rest the saved
* value.
*
* @example wavesurfer.toggleMute();
*/
toggleMute() {
this.setMute(!this.isMuted);
}
/**
* Enable or disable muted audio
*
* @param {boolean} mute
* @example
* // unmute
* wavesurfer.setMute(false);
*/
setMute(mute) {
// ignore all muting requests if the audio is already in that state
if (mute === this.isMuted) {
return;
}
if (mute) {
// If currently not muted then save current volume,
// turn off the volume and update the mute properties
this.savedVolume = this.backend.getVolume();
this.backend.setVolume(0);
this.isMuted = true;
} else {
// If currently muted then restore to the saved volume
// and update the mute properties
this.backend.setVolume(this.savedVolume);
this.isMuted = false;
}
}
/**
* Get the current mute status.
*
* @example const isMuted = wavesurfer.getMute();
* @return {boolean}
*/
getMute() {
return this.isMuted;
}
/**
* Get the list of current set filters as an array.
*
* Filters must be set with setFilters method first
*
* @return {array}
*/
getFilters() {
return this.backend.filters || [];
}
/**
* Toggles `scrollParent` and redraws
*
* @example wavesurfer.toggleScroll();
*/
toggleScroll() {
this.params.scrollParent = !this.params.scrollParent;
this.drawBuffer();
}
/**
* Toggle mouse interaction
*
* @example wavesurfer.toggleInteraction();
*/
toggleInteraction() {
this.params.interact = !this.params.interact;
}
/**
* Get the correct peaks for current wave viewport and render wave
*
* @private
* @emits WaveSurfer#redraw
*/
drawBuffer() {
const nominalWidth = Math.round(
this.getDuration() * this.params.minPxPerSec * this.params.pixelRatio
);
const parentWidth = this.drawer.getWidth();
let width = nominalWidth;
let start = this.drawer.getScrollX();
let end = Math.max(start + parentWidth, width);
// Fill container
if (this.params.fillParent && (!this.params.scrollParent || nominalWidth < parentWidth)) {
width = parentWidth;
start = 0;
end = width;
}
let peaks;
if (this.params.partialRender) {
const newRanges = this.peakCache.addRangeToPeakCache(width, start, end);
let i;
for (i = 0; i < newRanges.length; i++) {
peaks = this.backend.getPeaks(width, newRanges[i][0], newRanges[i][1]);
this.drawer.drawPeaks(peaks, width, newRanges[i][0], newRanges[i][1]);
}
} else {
peaks = this.backend.getPeaks(width, start, end);
this.drawer.drawPeaks(peaks, width, start, end);
}
this.fireEvent('redraw', peaks, width);
}
/**
* Horizontally zooms the waveform in and out. It also changes the parameter
* `minPxPerSec` and enables the `scrollParent` option. Calling the function
* with a falsey parameter will reset the zoom state.
*
* @param {?number} pxPerSec Number of horizontal pixels per second of
* audio, if none is set the waveform returns to unzoomed state
* @emits WaveSurfer#zoom
* @example wavesurfer.zoom(20);
*/
zoom(pxPerSec) {
if (!pxPerSec) {
this.params.minPxPerSec = this.defaultParams.minPxPerSec;
this.params.scrollParent = false;
} else {
this.params.minPxPerSec = pxPerSec;
this.params.scrollParent = true;
}
this.drawBuffer();
this.drawer.progress(this.backend.getPlayedPercents());
this.drawer.recenter(
this.getCurrentTime() / this.getDuration()
);
this.fireEvent('zoom', pxPerSec);
}
/**
* Decode buffer and load
*
* @private
* @param {ArrayBuffer} arraybuffer
*/
loadArrayBuffer(arraybuffer) {
this.decodeArrayBuffer(arraybuffer, data => {
if (!this.isDestroyed) {
this.loadDecodedBuffer(data);
}
});
}
/**
* Directly load an externally decoded AudioBuffer
*
* @private
* @param {AudioBuffer} buffer
* @emits WaveSurfer#ready
*/
loadDecodedBuffer(buffer) {
this.backend.load(buffer);
this.drawBuffer();
this.fireEvent('ready');
this.isReady = true;
}
/**
* Loads audio data from a Blob or File object
*
* @param {Blob|File} blob Audio data
* @example
*/
loadBlob(blob) {
// Create file reader
const reader = new FileReader();
reader.addEventListener('progress', e => this.onProgress(e));
reader.addEventListener('load', e => this.loadArrayBuffer(e.target.result));
reader.addEventListener('error', () => this.fireEvent('error', 'Error reading file'));
reader.readAsArrayBuffer(blob);
this.empty();
}
/**
* Loads audio and re-renders the waveform.
*
* @param {string} url The url of the audio file
* @param {?number[]|number[][]} peaks Wavesurfer does not have to decode the audio to
* render the waveform if this is specified
* @param {?string} preload (Use with backend `MediaElement`)
* `'none'|'metadata'|'auto'` Preload attribute for the media element
* @example
* // using ajax or media element to load (depending on backend)
* wavesurfer.load('http://example.com/demo.wav');
*
* // setting preload attribute with media element backend and supplying
* peaks wavesurfer.load(
* 'http://example.com/demo.wav',
* [0.0218, 0.0183, 0.0165, 0.0198, 0.2137, 0.2888],
* true,
* );
*/
load(url, peaks, preload) {
this.empty();
this.isMuted = false;
switch (this.params.backend) {
case 'WebAudio': return this.loadBuffer(url, peaks);
case 'MediaElement': return this.loadMediaElement(url, peaks, preload);
}
}
/**
* Loads audio using Web Audio buffer backend.
*
* @private
* @param {string} url
* @param {?number[]|number[][]} peaks
*/
loadBuffer(url, peaks) {
const load = action => {
if (action) {
this.tmpEvents.push(this.once('ready', action));
}
return this.getArrayBuffer(url, (data) => this.loadArrayBuffer(data));
};
if (peaks) {
this.backend.setPeaks(peaks);
this.drawBuffer();
this.tmpEvents.push(this.once('interaction', load));
} else {
return load();
}
}
/**
* Either create a media element, or load an existing media element.
*
* @private
* @param {string|HTMLElement} urlOrElt Either a path to a media file, or an
* existing HTML5 Audio/Video Element
* @param {number[]|number[][]} peaks Array of peaks. Required to bypass web audio
* dependency
* @param {?boolean} preload Set to true if the preload attribute of the
* audio element should be enabled
*/
loadMediaElement(urlOrElt, peaks, preload) {
let url = urlOrElt;
if (typeof urlOrElt === 'string') {
this.backend.load(url, this.mediaContainer, peaks, preload);
} else {
const elt = urlOrElt;
this.backend.loadElt(elt, peaks);
// If peaks are not provided,
// url = element.src so we can get peaks with web audio
url = elt.src;
}
this.tmpEvents.push(
this.backend.once('canplay', () => {
this.drawBuffer();
this.fireEvent('ready');
this.isReady = true;
}),
this.backend.once('error', err => this.fireEvent('error', err))
);
// If no pre-decoded peaks provided or pre-decoded peaks are
// provided with forceDecode flag, attempt to download the
// audio file and decode it with Web Audio.
if (peaks) {
this.backend.setPeaks(peaks);
}
if ((!peaks || this.params.forceDecode) && this.backend.supportsWebAudio()) {
this.getArrayBuffer(url, arraybuffer => {
this.decodeArrayBuffer(arraybuffer, buffer => {
this.backend.buffer = buffer;
this.backend.setPeaks(null);
this.drawBuffer();
this.fireEvent('waveform-ready');
});
});
}
}
/**
* Decode an array buffer and pass data to a callback
*
* @private
* @param {Object} arraybuffer
* @param {function} callback
*/
decodeArrayBuffer(arraybuffer, callback) {
this.arraybuffer = arraybuffer;
this.backend.decodeArrayBuffer(
arraybuffer,
data => {
// Only use the decoded data if we haven't been destroyed or
// another decode started in the meantime
if (!this.isDestroyed && this.arraybuffer == arraybuffer) {
callback(data);
this.arraybuffer = null;
}
},
() => this.fireEvent('error', 'Error decoding audiobuffer')
);
}
/**
* Load an array buffer by ajax and pass to a callback
*
* @param {string} url
* @param {function} callback
* @private
*/
getArrayBuffer(url, callback) {
const ajax = util.ajax({
url: url,
responseType: 'arraybuffer'
});
this.currentAjax = ajax;
this.tmpEvents.push(
ajax.on('progress', e => {
this.onProgress(e);
}),
ajax.on('success', (data, e) => {
callback(data);
this.currentAjax = null;
}),
ajax.on('error', e => {
this.fireEvent('error', 'XHR error: ' + e.target.statusText);
this.currentAjax = null;
})
);
return ajax;
}
/**
* Called while the audio file is loading
*
* @private
* @param {Event} e
* @emits WaveSurfer#loading
*/
onProgress(e) {
let percentComplete;
if (e.lengthComputable) {
percentComplete = e.loaded / e.total;
} else {
// Approximate progress with an asymptotic
// function, and assume downloads in the 1-3 MB range.
percentComplete = e.loaded / (e.loaded + 1000000);
}
this.fireEvent('loading', Math.round(percentComplete * 100), e.target);
}
/**
* Exports PCM data into a JSON array and opens in a new window.
*
* @param {number} length=1024 The scale in which to export the peaks. (Integer)
* @param {number} accuracy=10000 (Integer)
* @param {?boolean} noWindow Set to true to disable opening a new
* window with the JSON
* @param {number} start
* @todo Update exportPCM to work with new getPeaks signature
* @return {JSON} JSON of peaks
*/
exportPCM(length, accuracy, noWindow, start) {
length = length || 1024;
start = start || 0;
accuracy = accuracy || 10000;
noWindow = noWindow || false;
const peaks = this.backend.getPeaks(length, start);
const arr = [].map.call(peaks, val => Math.round(val * accuracy) / accuracy);
const json = JSON.stringify(arr);
if (!noWindow) {
window.open('data:application/json;charset=utf-8,' +
encodeURIComponent(json));
}
return json;
}
/**
* Save waveform image as data URI.
*
* The default format is `image/png`. Other supported types are
* `image/jpeg` and `image/webp`.
*
* @param {string} format='image/png'
* @param {number} quality=1
* @return {string} data URI of image
*/
exportImage(format, quality) {
if (!format) {
format = 'image/png';
}
if (!quality) {
quality = 1;
}
return this.drawer.getImage(format, quality);
}
/**
* Cancel any ajax request currently in progress
*/
cancelAjax() {
if (this.currentAjax) {
this.currentAjax.xhr.abort();
this.currentAjax = null;
}
}
/**
* @private
*/
clearTmpEvents() {
this.tmpEvents.forEach(e => e.un());
}
/**
* Display empty waveform.
*/
empty() {
if (!this.backend.isPaused()) {
this.stop();
this.backend.disconnectSource();
}
this.cancelAjax();
this.clearTmpEvents();
this.drawer.progress(0);
this.drawer.setWidth(0);
this.drawer.drawPeaks({ length: this.drawer.getWidth() }, 0);
}
/**
* Remove events, elements and disconnect WebAudio nodes.
*
* @emits WaveSurfer#destroy
*/
destroy() {
this.destroyAllPlugins();
this.fireEvent('destroy');
this.cancelAjax();
this.clearTmpEvents();
this.unAll();
if (this.params.responsive) {
window.removeEventListener('resize', this._onResize, true);
}
this.backend.destroy();
this.drawer.destroy();
this.isDestroyed = true;
this.arraybuffer = null;
}
}