public void Test_AGC_normWindow()
{
// strategy here is to create a weighted moving window mean and normalize to that
string wavFilePath = "../../../../../data/qrss-10min.wav";
(int sampleRate, double[] L) = WavFile.ReadMono(wavFilePath);
int fftSize = 8192;
var spec = new Spectrogram(sampleRate, fftSize, stepSize: 2000, maxFreq: 3000);
spec.Add(L);
var ffts = spec.GetFFTs();
for (int i = 0; i < ffts.Count; i++)
{
ffts[i] = SubtractMovingWindowFloor(ffts[i]);
}
spec.SaveImage("qrss-agc-norm-window.png", intensity: 3);
}
public void Test_AGC_normToNoiseFloor()
{
// strategy here is to normalize to the magnitude of the quietest 20% of frequencies
string wavFilePath = "../../../../../data/qrss-10min.wav";
(int sampleRate, double[] L) = WavFile.ReadMono(wavFilePath);
int fftSize = 8192;
var spec = new Spectrogram(sampleRate, fftSize, stepSize: 2000, maxFreq: 3000);
spec.Add(L);
var ffts = spec.GetFFTs();
double normalIntensity = 2;
for (int i = 0; i < ffts.Count; i++)
{
double[] sorted = new double[ffts[i].Length];
ffts[i].CopyTo(sorted, 0);
Array.Sort(sorted);
double percentile = 0.25;
int percentileIndex = (int)(percentile * ffts[0].Length);
double floorValue = sorted[percentileIndex];
for (int y = 0; y < ffts[i].Length; y++)
{
ffts[i][y] = ffts[i][y] / floorValue * normalIntensity;
}
Console.WriteLine(floorValue);
}
spec.SaveImage("qrss-agc-norm-floor.png", intensity: 3);
}
