meyda/src/extractors/spectralFlux.ts

Real-time feature extraction for the web audio api

// This file isn't being typechecked at all because there are major issues with it.
// See #852 for details. Once that's merged, this file should be typechecked.
// @ts-nocheck
export default function ({
  signal,
  previousSignal,
  bufferSize,
}: {
  signal: Float32Array;
  previousSignal: Float32Array;
  bufferSize: number;
}): number {
  if (typeof signal !== "object" || typeof previousSignal != "object") {
    throw new TypeError();
  }

  let sf = 0;
  for (let i = -(bufferSize / 2); i < signal.length / 2 - 1; i++) {
    x = Math.abs(signal[i]) - Math.abs(previousSignal[i]);
    sf += (x + Math.abs(x)) / 2;
  }

  return sf;
}