jiti-meet/react/features/local-recording/recording/AbstractAudioContextAdapter.js

129 lines
3.6 KiB
JavaScript
Raw Normal View History

import logger from '../logger';
import { RecordingAdapter } from './RecordingAdapter';
/**
* Base class for {@code AudioContext}-based recording adapters.
*/
export class AbstractAudioContextAdapter extends RecordingAdapter {
/**
* The {@code AudioContext} instance.
*/
_audioContext = null;
/**
* The {@code ScriptProcessorNode} instance.
*/
_audioProcessingNode = null;
/**
* The {@code MediaStreamAudioSourceNode} instance.
*/
_audioSource = null;
/**
* The {@code MediaStream} instance, representing the current audio device.
*/
_stream = null;
/**
* Sample rate.
*/
_sampleRate = 44100;
/**
* Constructor.
*/
constructor() {
super();
// sampleRate is browser and OS dependent.
// Setting sampleRate explicitly is in the specs but not implemented
// by browsers.
// See: https://developer.mozilla.org/en-US/docs/Web/API/AudioContext/
// AudioContext#Browser_compatibility
// And https://bugs.chromium.org/p/chromium/issues/detail?id=432248
this._audioContext = new AudioContext();
this._sampleRate = this._audioContext.sampleRate;
logger.log(`Current sampleRate ${this._sampleRate}.`);
}
/**
* Sets up the audio graph in the AudioContext.
*
* @protected
* @param {string} micDeviceId - The current microphone device ID.
* @param {Function} callback - Callback function to
* handle AudioProcessingEvents.
* @returns {Promise}
*/
_initializeAudioContext(micDeviceId, callback) {
if (typeof callback !== 'function') {
return Promise.reject('a callback function is required.');
}
return this._getAudioStream(micDeviceId)
.then(stream => {
this._stream = stream;
this._audioSource
= this._audioContext.createMediaStreamSource(stream);
this._audioProcessingNode
= this._audioContext.createScriptProcessor(4096, 1, 1);
this._audioProcessingNode.onaudioprocess = callback;
logger.debug('AudioContext is set up.');
})
.catch(err => {
logger.error(`Error calling getUserMedia(): ${err}`);
return Promise.reject(err);
});
}
/**
* Connects the nodes in the {@code AudioContext} to start the flow of
* audio data.
*
* @protected
* @returns {void}
*/
_connectAudioGraph() {
this._audioSource.connect(this._audioProcessingNode);
this._audioProcessingNode.connect(this._audioContext.destination);
}
/**
* Disconnects the nodes in the {@code AudioContext}.
*
* @protected
* @returns {void}
*/
_disconnectAudioGraph() {
this._audioProcessingNode.onaudioprocess = undefined;
this._audioProcessingNode.disconnect();
this._audioSource.disconnect();
}
/**
* Replaces the current microphone MediaStream.
*
* @protected
* @param {string} micDeviceId - New microphone ID.
* @returns {Promise}
*/
_replaceMic(micDeviceId) {
if (this._audioContext && this._audioProcessingNode) {
return this._getAudioStream(micDeviceId).then(newStream => {
const newSource = this._audioContext
.createMediaStreamSource(newStream);
this._audioSource.disconnect();
newSource.connect(this._audioProcessingNode);
this._stream = newStream;
this._audioSource = newSource;
});
}
return Promise.resolve();
}
}