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SonicForgeStudio/app/static/js/services/bridgeAudioWorklet.js
T

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3.0 KiB
JavaScript

// app/static/js/services/bridgeAudioWorklet.js
// VSTi crackle fix: audio sink chay tren audio thread (khong jank main thread).
// - Ring block 256 mau, toi da 8 block (~42ms @48k) — hap thu jitter pump
// nhung gioi han backlog: 64 block (~371ms) tao tre ~0.3-0.4s khi play/
// keyboard preview (audio moi phai cho ring cu chay het).
// - Underrun: fade ve 0 thay vi click (hard silence).
// - Resume sau silence: fade vao tu 0.
// - Overrun: drop block cu nhat + crossfade 64 mau tai diem drop (het click).
class BridgeAudioSinkProcessor extends AudioWorkletProcessor {
constructor() {
super();
this._ring = [];
this._MAX = 8;
this._gain = 1.0;
this._lastOutL = 0.0;
this._lastOutR = 0.0;
this._skipFade = 0; // >0: crossfade dang chay sau overrun drop
this._skipFromL = 0.0;
this._skipFromR = 0.0;
this.port.onmessage = (e) => {
const m = e.data;
if (!m) return;
if (m.type === 'audio') {
this._ring.push({ l: m.l, r: m.r });
while (this._ring.length > this._MAX) {
// overrun: bo block cu nhat; lan consume toi se crossfade ranh gioi
this._ring.shift();
this._skipFade = 64;
}
} else if (m.type === 'flush') {
this._ring.length = 0;
this._gain = 1.0;
this._skipFade = 0;
}
};
}
process(inputs, outputs) {
const out = outputs[0];
if (!out || out.length < 2) return true;
const L = out[0];
const R = out[1];
const n = L.length;
let w = 0;
while (w < n) {
if (this._ring.length) {
const blk = this._ring[0];
const avail = blk.l.length;
const take = Math.min(avail, n - w);
if (this._skipFade > 0) {
for (let i = 0; i < take; i++) {
const t = i / 64;
L[w + i] = (this._lastOutL * (1 - t) + blk.l[i] * t) * this._gain;
R[w + i] = (this._lastOutR * (1 - t) + blk.r[i] * t) * this._gain;
}
this._skipFade = Math.max(0, this._skipFade - take);
} else {
for (let i = 0; i < take; i++) {
L[w + i] = blk.l[i] * this._gain;
R[w + i] = blk.r[i] * this._gain;
}
}
this._lastOutL = L[w + take - 1];
this._lastOutR = R[w + take - 1];
if (this._gain < 1.0) this._gain = Math.min(1.0, this._gain + take / 256.0);
w += take;
if (take >= avail) {
this._ring.shift();
} else {
blk.l = blk.l.subarray(take);
blk.r = blk.r.subarray(take);
}
} else {
// underrun: fade ve 0 (khong click)
for (let i = w; i < n; i++) {
this._gain = Math.max(0, this._gain - 1.0 / 256.0);
L[i] = this._lastOutL * this._gain;
R[i] = this._lastOutR * this._gain;
}
this._lastOutL *= this._gain;
this._lastOutR *= this._gain;
w = n;
}
}
return true;
}
}
registerProcessor('bridge-audio-sink', BridgeAudioSinkProcessor);