librnnoise.worker.ts

interface AudioWorkletProcessor {
  readonly port: MessagePort;
  process(inputs: Float32Array[][], outputs: Float32Array[][], parameters: Map<string, Float32Array>): void;
}

declare var AudioWorkletProcessor: {
  prototype: AudioWorkletProcessor;
  new(options?: AudioWorkletNodeOptions): AudioWorkletProcessor;
}

declare function registerProcessor(name: string, cls: any);

class RNNoiseProcessor extends AudioWorkletProcessor {
  wasm_exports: any;
  handle: number;
  frame_size = 480;
  in_ptr: number;
  in_buf: Float32Array;
  out_ptr: number;
  out_buf: Float32Array;
  filled: number = 0;

  constructor() {
    super();
    this.port.onmessage = (e) => {
      WebAssembly.instantiate(e.data, {}).then((instance: any) => {
        this.wasm_exports = instance.exports;
        this.handle = this.wasm_exports.rnnoise_create(0);
        this.in_ptr = this.wasm_exports.malloc(this.frame_size * 4);
        this.out_ptr = this.wasm_exports.malloc(this.frame_size * 4);
        this.in_buf = new Float32Array(
          this.wasm_exports.memory.buffer, this.in_ptr, this.frame_size);
        this.out_buf = new Float32Array(
          this.wasm_exports.memory.buffer, this.out_ptr, this.frame_size);
      });
    };
  }

  process(inputs: Float32Array[][], outputs: Float32Array[][], parameters: any) {
    if (this.wasm_exports === undefined)
      return true;
    if (inputs.length !== 1 || outputs.length !== 1 || inputs[0].length == 0 || inputs[0][0] === undefined)
      return true;
    let input = inputs[0][0];
    let output = outputs[0][0];

    while (input.length > 0) {
      const sz = Math.min(input.length, this.in_buf.length - this.filled);
      for (let i = 0; i < sz; i++)
        this.in_buf[this.filled + i] = input[i] * (2**15);
      this.filled += sz;
      input = input.subarray(sz);

      if (this.filled == this.in_buf.length) {
        const score = this.wasm_exports.rnnoise_process_frame(this.handle, this.out_ptr, this.in_ptr);
        this.port.postMessage(score);
        this.filled = 0;
      }
    }
    return true;
  }
}
registerProcessor('rnnoise-processor', RNNoiseProcessor);