static float shortSamplesToPercentVolume(short[] samples) {
  int min = 32767, max = -32768, n = l(samples);
  for i to n: {
    short sample = samples[i];
    min = min(min, sample);
    max = max(max, sample);
  }
  ret (float) (100*min(1, max(0, max-min)/65534.0));
}