public bool Run(float[] data, float deltaTime)
{
syllableDetected = false;
float sumIntensity = 0;
if (!SinglePolaity(data)) // Here to easily take out artifacts found on my poor desktop mic
{
sumIntensity = SumAbsIntensity(data);
level = sumIntensity / data.Length;
float mean = SumIntensity(data) / data.Length;
int sampleOffsetHigh;
int sampleOffsetLow;
FrequencyBandToSampleOffsets(data.Length, sampleRate, 80, 300, out sampleOffsetHigh, out sampleOffsetLow); // was 80,900
float newNPA = DoNormalisedPeakAutocorrelation(data, mean, sampleOffsetHigh, sampleOffsetLow);
normalisedPeakAutocorrelation += (newNPA - normalisedPeakAutocorrelation) * deltaTime * 10;
DipTracking();
// If we're using the periodicity, check that the normalised value is high before
// considering it
if (normalisedPeakAutocorrelation > npaThreshold)
{
peak = Math.Max(peak, level);
PeakPicking();
}
}
else
{
level = 0;
}
if (syllableDetected)
{
totalSyllables++;
}
LogMT.SendStreamValue("MTdt", deltaTime);
LogMT.SendStreamValue("MTnpa", normalisedPeakAutocorrelation);
LogMT.SendStreamValue("MTlvl", level);
LogMT.SendStreamValue("MTpek", peak);
LogMT.SendStreamValue("MTdip", dip);
LogMT.SendStreamValue("MTdpd", Convert.ToInt32(dipped));
LogMT.SendStreamValue("MTsbs", totalSyllables);
return(syllableDetected);
}
/// <summary>
/// Calculates the peak of the normalised autocorrelation of a window of samples,
/// with an offset within a given band.
/// </summary>
private static float DoNormalisedPeakAutocorrelation(float[] window,
float mean,
int sampleOffsetHigh,
int sampleOffsetLow)
{
float highest = 0;
float[] gammaA = new float[sampleOffsetHigh - sampleOffsetLow + 1];
float sumZero = 0;
for (int t = 0; t < window.Length - 0; t++)
{
sumZero += window[t + 0] * window[t];
}
float gammaZero = sumZero / window.Length;
for (int h = sampleOffsetHigh; h >= sampleOffsetLow; h--)
{
float sum = 0;
for (int t = 0; t < window.Length - h; t++)
{
sum += (window[t + h] - mean) * (window[t] - mean);
}
float gamma = (sum / window.Length) / (window.Length - h);
if (gamma > highest)
{
highest = gamma;
}
float norm = highest / (gammaZero / window.Length);
gammaA[h - sampleOffsetLow] = norm;
}
// Here we normalise the peak value so it is between 0 and 1
float normalised = highest / (gammaZero / window.Length);
LogMT.SendStreamValue("MTsoL", sampleOffsetLow);
LogMT.SendStreamValue("MTsoH", sampleOffsetHigh);
LogMT.SendStreamValueBlock("MTatc", gammaA);
return(normalised);
}
