81 lines
2.5 KiB
TypeScript
81 lines
2.5 KiB
TypeScript
import { AudioContext, IAnalyserNode, IAudioContext, IMediaStreamAudioSourceNode } from "standardized-audio-context";
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/**
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* Class to measure the sound volume of a media stream
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*/
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export class SoundMeter {
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private instant: number;
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private clip: number;
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private analyser: IAnalyserNode<IAudioContext> | undefined;
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private dataArray: Uint8Array | undefined;
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private context: IAudioContext | undefined;
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private source: IMediaStreamAudioSourceNode<IAudioContext> | undefined;
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constructor(mediaStream: MediaStream) {
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this.instant = 0.0;
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this.clip = 0.0;
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this.connectToSource(mediaStream, new AudioContext());
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}
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public getVolume(): number {
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if (this.context === undefined || this.dataArray === undefined || this.analyser === undefined) {
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return 0;
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}
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this.analyser.getByteFrequencyData(this.dataArray);
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const input = this.dataArray;
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let i;
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let sum = 0.0;
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//let clipcount = 0;
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for (i = 0; i < input.length; ++i) {
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sum += input[i] * input[i];
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// if (Math.abs(input[i]) > 0.99) {
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// clipcount += 1;
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// }
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}
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this.instant = Math.sqrt(sum / input.length);
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//this.slow = 0.95 * that.slow + 0.05 * that.instant;
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//this.clip = clipcount / input.length;
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return this.instant;
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}
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public stop(): void {
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if (this.context === undefined) {
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return;
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}
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if (this.source !== undefined) {
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this.source.disconnect();
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}
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this.context = undefined;
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this.analyser = undefined;
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this.dataArray = undefined;
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this.source = undefined;
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}
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private init(context: IAudioContext) {
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this.context = context;
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this.analyser = this.context.createAnalyser();
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this.analyser.fftSize = 2048;
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const bufferLength = this.analyser.fftSize;
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this.dataArray = new Uint8Array(bufferLength);
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}
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private connectToSource(stream: MediaStream, context: IAudioContext): void {
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if (this.source !== undefined) {
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this.stop();
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}
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this.init(context);
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this.source = this.context?.createMediaStreamSource(stream);
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if (this.analyser !== undefined) {
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this.source?.connect(this.analyser);
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}
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//analyser.connect(distortion);
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//distortion.connect(this.context.destination);
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//this.analyser.connect(this.context.destination);
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}
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}
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