74 lines
2.5 KiB
JavaScript
74 lines
2.5 KiB
JavaScript
export class AudioManager {
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constructor() {
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this.context = null;
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this.rawStream = null;
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this.outputStream = null;
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this.source = null;
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this.gainNode = null;
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this.analyser = null;
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this.meterSink = null;
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this.meterData = new Float32Array(1024);
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this.gain = Number(localStorage.getItem('voicepoc.micGain') || 1);
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}
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async ensureContext() {
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if (!this.context) this.context = new AudioContext();
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await this.context.resume().catch(() => {});
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return this.context;
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}
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async attachInput(stream) {
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await this.ensureContext();
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this.detachInput();
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this.rawStream = stream;
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this.source = this.context.createMediaStreamSource(stream);
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this.gainNode = this.context.createGain();
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this.gainNode.gain.value = this.gain;
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this.analyser = this.context.createAnalyser();
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this.analyser.fftSize = 1024;
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this.meterSink = this.context.createGain();
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this.meterSink.gain.value = 0;
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const destination = this.context.createMediaStreamDestination();
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this.source.connect(this.gainNode).connect(this.analyser);
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// Keep the analyser alive without sending the microphone to the speakers.
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this.analyser.connect(this.meterSink).connect(this.context.destination);
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this.gainNode.connect(destination);
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this.outputStream = destination.stream;
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return this.outputStream;
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}
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detachInput() {
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for (const node of [this.source, this.gainNode, this.analyser, this.meterSink]) {
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try { node?.disconnect(); } catch {}
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}
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this.outputStream?.getTracks().forEach((track) => track.stop());
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this.rawStream?.getTracks().forEach((track) => track.stop());
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this.source = this.gainNode = this.analyser = this.meterSink = null;
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this.outputStream = this.rawStream = null;
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}
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setGain(value) {
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this.gain = Math.max(0, Math.min(2, Number(value) || 0));
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localStorage.setItem('voicepoc.micGain', String(this.gain));
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if (this.gainNode) this.gainNode.gain.setTargetAtTime(this.gain, this.context.currentTime, 0.015);
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}
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getLevel() {
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if (!this.analyser) return { rms: 0, peak: 0, clipping: false };
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this.analyser.getFloatTimeDomainData(this.meterData);
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let sum = 0;
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let peak = 0;
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for (const sample of this.meterData) {
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const magnitude = Math.abs(sample);
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sum += sample * sample;
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peak = Math.max(peak, magnitude);
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}
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const rms = Math.sqrt(sum / this.meterData.length);
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return { rms, peak, clipping: peak >= 0.98 };
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}
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stop() {
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this.detachInput();
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}
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}
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