public void Test_SaveEmpty_Throws()
{
(int sampleRate, double[] audio) = WavFile.ReadMono("../../../../../data/cant-do-that-44100.wav");
int fftSize = 4096;
var spec = new Spectrogram(sampleRate, fftSize, stepSize: 500);
//spec.Add(audio);
Assert.Throws <InvalidOperationException>(() => { spec.SaveImage("empty.png"); });
}
public void Test_Quickstart_Hal()
{
(int sampleRate, double[] audio) = WavFile.ReadMono("../../../../../data/cant-do-that-44100.wav");
int fftSize = 4096;
var spec = new Spectrogram(sampleRate, fftSize, stepSize: 500, maxFreq: 3000);
spec.Add(audio);
spec.SaveImage("../../../../../dev/graphics/hal.png", intensity: .2);
Console.WriteLine(spec);
}
public void Test_AGC_off()
{
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);
spec.SaveImage("qrss-agc-off.png", intensity: 3);
}
public void Test_Mel_Spectrogram()
{
(int sampleRate, double[] audio) = WavFile.ReadMono("../../../../../data/cant-do-that-44100.wav");
int fftSize = 4096;
var spec = new Spectrogram(sampleRate, fftSize, stepSize: 500);
spec.Add(audio);
spec.SaveImage("halNotMel.png", 4, true);
Bitmap bmp = spec.GetBitmapMel(250, 4, true);
bmp.Save("../../../../../dev/graphics/halMel.png", ImageFormat.Png);
}
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_Make_CommonColormaps()
{
(int sampleRate, double[] audio) = WavFile.ReadMono("../../../../../data/cant-do-that-44100.wav");
int fftSize = 1 << 12;
var spec = new Spectrogram(sampleRate, fftSize, stepSize: 700, maxFreq: 2000);
spec.SetWindow(FftSharp.Window.Hanning(fftSize / 3)); // sharper window than typical
spec.Add(audio);
// delete old colormap files
foreach (var filePath in System.IO.Directory.GetFiles("../../../../../dev/graphics/", "hal-*.png"))
{
System.IO.File.Delete(filePath);
}
foreach (var cmap in Colormap.GetColormaps())
{
spec.SetColormap(cmap);
spec.SaveImage($"../../../../../dev/graphics/hal-{cmap.Name}.png", intensity: .5);
Debug.WriteLine($"");
}
}
public void Test_Quickstart_Handel()
{
double[] audio = Mp3.Read("../../../../../data/Handel - Air and Variations.mp3");
int sampleRate = 44100;
int fftSize = 16384;
int targetWidthPx = 3000;
int stepSize = audio.Length / targetWidthPx;
var spec = new Spectrogram(sampleRate, fftSize, stepSize, maxFreq: 2200);
spec.Add(audio);
spec.SaveImage("../../../../../dev/spectrogram-song.jpg", intensity: 5, dB: true);
Console.WriteLine(spec);
/*
* Spectrogram (2993, 817)
* Vertical (817 px): 0 - 2,199 Hz, FFT size: 16,384 samples, 2.69 Hz/px
* Horizontal (2993 px): 2.96 min, window: 0.37 sec, step: 0.06 sec, overlap: 84%
*/
}
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);
}