auto_correlation.cpp

static autoCorr_t
_auto_corr(samples_t const samples, samplesLag_t const lag)
{
  autoCorr_t ac = 0;
  for (sample_cnt_t ii = 0; ii < CONFIG_MIDIMIKE_WINDOW_SIZE - lag; ii++) {
    ac += ((int16_t)samples[ii] * samples[ii + lag]);
  }
  return ac;
}