Method process

ts/workers/mp3Encoder.std.ts:89–153

(inputs: Array<Array<Float32Array<ArrayBuffer>>>)

  }

  process(inputs: Array<Array<Float32Array<ArrayBuffer>>>): boolean {
    if (this.#isStopped) {
      return false;
    }

    const [input] = inputs;
    if (input == null) {
      throw new Error(`Invalid input count: ${inputs.length}`);
    }

    const [channel] = input;
    if (channel == null) {
      return true;
    }

    for (const sample of channel) {
      this.#peakSquares += sample ** 2;
      this.#peakSamples += 1;
      if (this.#peakSamples < PEAK_EVERY) {
        continue;
      }

      const peak = Math.min(
        1,
        Math.max(0, Math.sqrt(this.#peakSquares / this.#peakSamples))
      );
      this.#window[this.#windowOffset] = peak;
      this.#windowOffset = (this.#windowOffset + 1) % WINDOW_SIZE;

      let max = 1e-23;
      for (const oldPeak of this.#window) {
        max = Math.max(max, oldPeak);
      }

      this.#previousMax *= MAX_DECAY;
      if (this.#previousMax < max) {
        this.#previousMax = max;
      } else {
        max = this.#previousMax;
      }

      this.#peakSquares = 0;
      this.#peakSamples = 0;

      this.port.postMessage({
        type: 'peak',
        peak: peak / max,
      } satisfies WorkletMessageType);
    }

    const shared = this.#encoder.encode(channel);
    if (shared.length === 0) {
      return true;
    }

    const copy = new Uint8Array(shared);
    this.port.postMessage(
      {