workadventure/front/src/Phaser/Components/SoundMeter.ts
2020-06-24 15:35:07 +02:00

139 lines
4.1 KiB
TypeScript

/**
* Class to measure the sound volume of a media stream
*/
export class SoundMeter {
private instant: number;
private clip: number;
//private script: ScriptProcessorNode;
private analyser: AnalyserNode|undefined;
private dataArray: Uint8Array|undefined;
private context: AudioContext|undefined;
private source: MediaStreamAudioSourceNode|undefined;
constructor() {
this.instant = 0.0;
this.clip = 0.0;
//this.script = context.createScriptProcessor(2048, 1, 1);
}
private init(context: AudioContext) {
if (this.context === undefined) {
this.context = context;
this.analyser = this.context.createAnalyser();
this.analyser.fftSize = 2048;
const bufferLength = this.analyser.fftSize;
this.dataArray = new Uint8Array(bufferLength);
}
}
public connectToSource(stream: MediaStream, context: AudioContext): void
{
this.init(context);
this.source = this.context?.createMediaStreamSource(stream);
if (this.analyser !== undefined) {
this.source?.connect(this.analyser);
}
//analyser.connect(distortion);
//distortion.connect(this.context.destination);
//this.analyser.connect(this.context.destination);
}
public getVolume(): number {
if (this.context === undefined || this.dataArray === undefined || this.analyser === undefined) {
return 0;
}
this.analyser.getByteFrequencyData(this.dataArray);
const input = this.dataArray;
let i;
let sum = 0.0;
//let clipcount = 0;
for (i = 0; i < input.length; ++i) {
sum += input[i] * input[i];
// if (Math.abs(input[i]) > 0.99) {
// clipcount += 1;
// }
}
this.instant = Math.sqrt(sum / input.length);
//this.slow = 0.95 * that.slow + 0.05 * that.instant;
//this.clip = clipcount / input.length;
//console.log('instant', this.instant, 'clip', this.clip);
return this.instant;
}
public stop(): void {
if (this.context === undefined) {
return;
}
if (this.source !== undefined) {
this.source.disconnect();
}
this.context = undefined;
this.analyser = undefined;
this.dataArray = undefined;
this.source = undefined;
}
}
// Meter class that generates a number correlated to audio volume.
// The meter class itself displays nothing, but it makes the
// instantaneous and time-decaying volumes available for inspection.
// It also reports on the fraction of samples that were at or near
// the top of the measurement range.
/*function SoundMeter(context) {
this.context = context;
this.instant = 0.0;
this.slow = 0.0;
this.clip = 0.0;
this.script = context.createScriptProcessor(2048, 1, 1);
const that = this;
this.script.onaudioprocess = function(event) {
const input = event.inputBuffer.getChannelData(0);
let i;
let sum = 0.0;
let clipcount = 0;
for (i = 0; i < input.length; ++i) {
sum += input[i] * input[i];
if (Math.abs(input[i]) > 0.99) {
clipcount += 1;
}
}
that.instant = Math.sqrt(sum / input.length);
that.slow = 0.95 * that.slow + 0.05 * that.instant;
that.clip = clipcount / input.length;
};
}
SoundMeter.prototype.connectToSource = function(stream, callback) {
console.log('SoundMeter connecting');
try {
this.mic = this.context.createMediaStreamSource(stream);
this.mic.connect(this.script);
// necessary to make sample run, but should not be.
this.script.connect(this.context.destination);
if (typeof callback !== 'undefined') {
callback(null);
}
} catch (e) {
console.error(e);
if (typeof callback !== 'undefined') {
callback(e);
}
}
};
SoundMeter.prototype.stop = function() {
this.mic.disconnect();
this.script.disconnect();
};
*/