src/plugin/microphone/index.js
/**
* @typedef {Object} MicrophonePluginParams
* @property {MediaStreamConstraints} constraints The constraints parameter is a
* MediaStreamConstaints object with two members: video and audio, describing
* the media types requested. Either or both must be specified.
* @property {number} bufferSize=4096 The buffer size in units of sample-frames.
* If specified, the bufferSize must be one of the following values: `256`,
* `512`, `1024`, `2048`, `4096`, `8192`, `16384`
* @property {number} numberOfInputChannels=1 Integer specifying the number of
* channels for this node's input. Values of up to 32 are supported.
* @property {number} numberOfOutputChannels=1 Integer specifying the number of
* channels for this node's output.
* @property {?boolean} deferInit Set to true to manually call
* `initPlugin('microphone')`
*/
/**
* Visualize microphone input in a wavesurfer instance.
*
* @implements {PluginClass}
* @extends {Observer}
* @example
* // es6
* import MicrophonePlugin from 'wavesurfer.microphone.js';
*
* // commonjs
* var MicrophonePlugin = require('wavesurfer.microphone.js');
*
* // if you are using <script> tags
* var MicrophonePlugin = window.WaveSurfer.microphone;
*
* // ... initialising wavesurfer with the plugin
* var wavesurfer = WaveSurfer.create({
* // wavesurfer options ...
* plugins: [
* MicrophonePlugin.create({
* // plugin options ...
* })
* ]
* });
*/
export default class MicrophonePlugin {
/**
* Microphone 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 {MicrophonePluginParams} params parameters use to initialise the plugin
* @return {PluginDefinition} an object representing the plugin
*/
static create(params) {
return {
name: 'microphone',
deferInit: params && params.deferInit ? params.deferInit : false,
params: params,
instance: MicrophonePlugin
};
}
constructor(params, ws) {
this.params = params;
this.wavesurfer = ws;
this.active = false;
this.paused = false;
this.browser = this.detectBrowser();
this.reloadBufferFunction = e => this.reloadBuffer(e);
// cross-browser getUserMedia
const promisifiedOldGUM = (
constraints,
successCallback,
errorCallback
) => {
// get a hold of getUserMedia, if present
const getUserMedia =
navigator.getUserMedia ||
navigator.webkitGetUserMedia ||
navigator.mozGetUserMedia ||
navigator.msGetUserMedia;
// Some browsers just don't implement it - return a rejected
// promise with an error to keep a consistent interface
if (!getUserMedia) {
return Promise.reject(
new Error('getUserMedia is not implemented in this browser')
);
}
// otherwise, wrap the call to the old navigator.getUserMedia with
// a Promise
return new Promise((successCallback, errorCallback) => {
getUserMedia.call(
navigator,
constraints,
successCallback,
errorCallback
);
});
};
// Older browsers might not implement mediaDevices at all, so we set an
// empty object first
if (navigator.mediaDevices === undefined) {
navigator.mediaDevices = {};
}
// Some browsers partially implement mediaDevices. We can't just assign
// an object with getUserMedia as it would overwrite existing
// properties. Here, we will just add the getUserMedia property if it's
// missing.
if (navigator.mediaDevices.getUserMedia === undefined) {
navigator.mediaDevices.getUserMedia = promisifiedOldGUM;
}
this.constraints = this.params.constraints || {
video: false,
audio: true
};
this.bufferSize = this.params.bufferSize || 4096;
this.numberOfInputChannels = this.params.numberOfInputChannels || 1;
this.numberOfOutputChannels = this.params.numberOfOutputChannels || 1;
this._onBackendCreated = () => {
// wavesurfer's AudioContext where we'll route the mic signal to
this.micContext = this.wavesurfer.backend.getAudioContext();
};
}
init() {
this.wavesurfer.on('backend-created', this._onBackendCreated);
if (this.wavesurfer.backend) {
this._onBackendCreated();
}
}
/**
* Destroy the microphone plugin.
*/
destroy() {
// make sure the buffer is not redrawn during
// cleanup and demolition of this plugin.
this.paused = true;
this.wavesurfer.un('backend-created', this._onBackendCreated);
this.stop();
}
/**
* Allow user to select audio input device, e.g. microphone, and
* start the visualization.
*/
start() {
navigator.mediaDevices
.getUserMedia(this.constraints)
.then(data => this.gotStream(data))
.catch(data => this.deviceError(data));
}
/**
* Pause/resume visualization.
*/
togglePlay() {
if (!this.active) {
// start it first
this.start();
} else {
// toggle paused
this.paused = !this.paused;
if (this.paused) {
this.pause();
} else {
this.play();
}
}
}
/**
* Play visualization.
*/
play() {
this.paused = false;
this.connect();
}
/**
* Pause visualization.
*/
pause() {
this.paused = true;
// disconnect sources so they can be used elsewhere
// (eg. during audio playback)
this.disconnect();
}
/**
* Stop the device stream and remove any remaining waveform drawing from
* the wavesurfer canvas.
*/
stop() {
if (this.active) {
// stop visualization and device
this.stopDevice();
// empty last frame
this.wavesurfer.empty();
}
}
/**
* Stop the device and the visualization.
*/
stopDevice() {
this.active = false;
// stop visualization
this.disconnect();
// stop stream from device
if (this.stream && this.stream.getTracks) {
this.stream.getTracks().forEach(stream => stream.stop());
}
}
/**
* Connect the media sources that feed the visualization.
*/
connect() {
if (this.stream !== undefined) {
// Create a local buffer for data to be copied to the Wavesurfer buffer for Edge
if (this.browser.browser === 'edge') {
this.localAudioBuffer = this.micContext.createBuffer(
this.numberOfInputChannels,
this.bufferSize,
this.micContext.sampleRate
);
}
// Create an AudioNode from the stream.
this.mediaStreamSource = this.micContext.createMediaStreamSource(
this.stream
);
this.levelChecker = this.micContext.createScriptProcessor(
this.bufferSize,
this.numberOfInputChannels,
this.numberOfOutputChannels
);
this.mediaStreamSource.connect(this.levelChecker);
this.levelChecker.connect(this.micContext.destination);
this.levelChecker.onaudioprocess = this.reloadBufferFunction;
}
}
/**
* Disconnect the media sources that feed the visualization.
*/
disconnect() {
if (this.mediaStreamSource !== undefined) {
this.mediaStreamSource.disconnect();
}
if (this.levelChecker !== undefined) {
this.levelChecker.disconnect();
this.levelChecker.onaudioprocess = undefined;
}
if (this.localAudioBuffer !== undefined) {
this.localAudioBuffer = undefined;
}
}
/**
* Redraw the waveform.
*
* @param {object} event Audioprocess event
*/
reloadBuffer(event) {
if (!this.paused) {
this.wavesurfer.empty();
if (this.browser.browser === 'edge') {
// copy audio data to a local audio buffer,
// from https://github.com/audiojs/audio-buffer-utils
let channel, l;
for (
channel = 0,
l = Math.min(
this.localAudioBuffer.numberOfChannels,
event.inputBuffer.numberOfChannels
);
channel < l;
channel++
) {
this.localAudioBuffer
.getChannelData(channel)
.set(event.inputBuffer.getChannelData(channel));
}
this.wavesurfer.loadDecodedBuffer(this.localAudioBuffer);
} else {
this.wavesurfer.loadDecodedBuffer(event.inputBuffer);
}
}
}
/**
* Audio input device is ready.
*
* @param {MediaStream} stream The microphone's media stream.
*/
gotStream(stream) {
this.stream = stream;
this.active = true;
// start visualization
this.play();
// notify listeners
this.fireEvent('deviceReady', stream);
}
/**
* Device error callback.
*
* @param {string} code Error message
*/
deviceError(code) {
// notify listeners
this.fireEvent('deviceError', code);
}
/**
* Extract browser version out of the provided user agent string.
* @param {!string} uastring userAgent string.
* @param {!string} expr Regular expression used as match criteria.
* @param {!number} pos position in the version string to be returned.
* @return {!number} browser version.
*/
extractVersion(uastring, expr, pos) {
const match = uastring.match(expr);
return match && match.length >= pos && parseInt(match[pos], 10);
}
/**
* Browser detector.
* @return {object} result containing browser, version and minVersion
* properties.
*/
detectBrowser() {
// Returned result object.
const result = {};
result.browser = null;
result.version = null;
result.minVersion = null;
// Non supported browser.
if (typeof window === 'undefined' || !window.navigator) {
result.browser = 'Not a supported browser.';
return result;
}
if (navigator.mozGetUserMedia) {
// Firefox
result.browser = 'firefox';
result.version = this.extractVersion(
navigator.userAgent,
/Firefox\/(\d+)\./,
1
);
result.minVersion = 31;
return result;
} else if (navigator.webkitGetUserMedia) {
// Chrome/Chromium/Webview/Opera
result.browser = 'chrome';
result.version = this.extractVersion(
navigator.userAgent,
/Chrom(e|ium)\/(\d+)\./,
2
);
result.minVersion = 38;
return result;
} else if (
navigator.mediaDevices &&
navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)
) {
// Edge
result.browser = 'edge';
result.version = this.extractVersion(
navigator.userAgent,
/Edge\/(\d+).(\d+)$/,
2
);
result.minVersion = 10547;
return result;
} else if (
window.RTCPeerConnection &&
navigator.userAgent.match(/AppleWebKit\/(\d+)\./)
) {
// Safari
result.browser = 'safari';
result.minVersion = 11;
result.version = this.extractVersion(
navigator.userAgent,
/AppleWebKit\/(\d+)\./,
1
);
return result;
}
// Non supported browser default.
result.browser = 'Not a supported browser.';
return result;
}
}
