private double[] FFT_from_PCM(double[] pcm)
{
// use the largest FFT size we can given the data (must be a power of 2)
int fftPoints = 2;
while (fftPoints * 2 <= pcm.Length)
{
fftPoints *= 2;
}
// prepare the complex data which will be FFT'd (using a window function)
NAudio.Dsp.Complex[] fftFull = new NAudio.Dsp.Complex[fftPoints];
for (int i = 0; i < fftPoints; i++)
{
fftFull[i].X = (float)(pcm[i] * NAudio.Dsp.FastFourierTransform.HammingWindow(i, fftPoints));
}
// perform the FFT
NAudio.Dsp.FastFourierTransform.FFT(true, (int)Math.Log(fftPoints, 2.0), fftFull);
// average (sum) the mirror image frequency powers
double[] fft = new double[fftPoints / 2];
for (int i = 0; i < fftPoints / 2; i++)
{
double fftLeft = Math.Abs(fftFull[i].X + fftFull[i].Y);
double fftRight = Math.Abs(fftFull[fftPoints - i - 1].X + fftFull[fftPoints - i - 1].Y);
fft[i] = fftLeft + fftRight;
}
return(fft);
}
private void updateFFT()
{
// the PCM size to be analyzed with FFT must be a power of 2
int fftPoints = 2;
while (fftPoints * 2 <= dataPcm.Length)
{
fftPoints *= 2;
}
// apply a Hamming window function as we load the FFT array then calculate the FFT
NAudio.Dsp.Complex[] fftFull = new NAudio.Dsp.Complex[fftPoints];
for (int i = 0; i < fftPoints; i++)
{
fftFull[i].X = (float)(dataPcm[i] * NAudio.Dsp.FastFourierTransform.HammingWindow(i, fftPoints));
}
NAudio.Dsp.FastFourierTransform.FFT(true, (int)Math.Log(fftPoints, 2.0), fftFull);
// copy the complex values into the double array that will be plotted
if (dataFft == null)
{
dataFft = new double[fftPoints];
}
for (int i = 0; i < fftPoints; i++)
{
double fftLeft = Math.Abs(fftFull[i].X + fftFull[i].Y);
double fftRight = Math.Abs(fftFull[fftPoints - i - 1].X + fftFull[fftPoints - i - 1].Y);
dataFft[i] = fftLeft + fftRight;
//dataFft[i] = Math.Sqrt(fftFull[i].X * fftFull[i].X + fftFull[i].Y * fftFull[i].Y);
}
}
private void updateFFT()
{
// размер PCM для анализа с помощью БПФ должен быть степенью 2
int fftPoints = 2;
while (fftPoints * 2 <= dataPcm.Length)
{
fftPoints *= 2;
}
// применяем оконную функцию Хэмминга при загрузке массива FFT, затем вычисляем FFT
NAudio.Dsp.Complex[] fftFull = new NAudio.Dsp.Complex[fftPoints];
for (int i = 0; i < fftPoints; i++)
{
fftFull[i].X = (float)(dataPcm[i] * NAudio.Dsp.FastFourierTransform.HammingWindow(i, fftPoints));
}
NAudio.Dsp.FastFourierTransform.FFT(true, (int)Math.Log(fftPoints, 2.0), fftFull);
// копируем комплексные значения в двойной массив, который будет построен
if (dataFft == null)
{
dataFft = new double[fftPoints / 2];
}
for (int i = 0; i < fftPoints / 2; i++)
{
double fftLeft = Math.Abs(fftFull[i].X + fftFull[i].Y);
double fftRight = Math.Abs(fftFull[fftPoints - i - 1].X + fftFull[fftPoints - i - 1].Y);
dataFft[i] = fftLeft + fftRight;
}
}
private void updateFFT()
{
if (dataPcm == null)
{
return;
}
int fftPoints = 2;
while (fftPoints * 2 <= dataPcm.Length)
{
fftPoints *= 2;
}
NAudio.Dsp.Complex[] fftFull = new NAudio.Dsp.Complex[fftPoints];
for (int i = 0; i < fftPoints; i++)
{
fftFull[i].X = (float)(dataPcm[i] * NAudio.Dsp.FastFourierTransform.HammingWindow(i, fftPoints));
}
NAudio.Dsp.FastFourierTransform.FFT(true, (int)Math.Log(fftPoints, 2.0), fftFull);
if (dataFft == null)
{
dataFft = new double[fftPoints / 2];
}
for (int i = 0; i < fftPoints / 2; i++)
{
double fftLeft = Math.Abs(fftFull[i].X + fftFull[i].Y);
double fftRight = Math.Abs(fftFull[fftPoints - i - 1].X + fftFull[fftPoints - i - 1].Y);
dataFft[i] = fftLeft + fftRight;
}
}
public override void Draw()
{
Graphics.SetColor(1, 1, 1);
if (buffer == null)
{
Graphics.Print("No buffer available");
return;
}
int len = buffer.FloatBuffer.Length / 8;
// fft
NAudio.Dsp.Complex[] values = new NAudio.Dsp.Complex[len];
for (int i = 0; i < len; i++)
{
values[i].Y = 0;
values[i].X = buffer.FloatBuffer[i];
}
NAudio.Dsp.FastFourierTransform.FFT(true, M, values);
float size = (float)WindowWidth / ((float)Math.Pow(2, M) / 2);
for (int i = 1; i < Math.Pow(2, M) / 2; i++)
{
//Graphics.Print(i.ToString() + ": " + values[i].X.ToString("N2") + " i " + (values[i].Y + 0.50f).ToString("N2"), 0, (i + 1) * 16);
Graphics.Rectangle(DrawMode.Fill, (i - 1) * size, WindowHeight / 2, size, -Math.Abs(values[i].X) * (WindowHeight / 2) * 10);
}
}
public static float[] FFT(float[] values, WindowFunction window = WindowFunction.hanning)
{
int fftSize = values.Length;
if (!IsPowerOfTwo(fftSize))
{
throw new ArgumentException("FFT Size must be a power of 2");
}
NAudio.Dsp.Complex[] fft_buffer = new NAudio.Dsp.Complex[fftSize];
for (int i = 0; i < fftSize; i++)
{
fft_buffer[i].X = (float)values[i];
fft_buffer[i].Y = 0;
switch (window)
{
case WindowFunction.none:
break;
case WindowFunction.hanning:
fft_buffer[i].X *= (float)NAudio.Dsp.FastFourierTransform.HammingWindow(i, fftSize);
break;
case WindowFunction.triangle:
fft_buffer[i].X *= (float)TriangleWindow(i, fftSize);
break;
default:
throw new NotImplementedException("unsupported window function");
}
}
NAudio.Dsp.FastFourierTransform.FFT(true, (int)Math.Log(fftSize, 2.0), fft_buffer);
float[] fft = new float[fftSize / 2];
for (int i = 0; i < fft.Length; i++)
{
var fftL = fft_buffer[i];
var fftR = fft_buffer[fft_buffer.Length - i - 1];
// note that this is different than just taking the absolute value
float absL = (float)Math.Sqrt(fftL.X * fftL.X + fftL.Y * fftL.Y);
float absR = (float)Math.Sqrt(fftR.X * fftR.X + fftR.Y * fftR.Y);
fft[i] = (absL + absR) / 2;
}
return(fft);
}
private void SetDataFFT(WaveInEventArgs args)
{
int bytesPerSample = _wi.WaveFormat.BitsPerSample / 8;
int samplesRecorded = args.BytesRecorded / bytesPerSample;
Int16[] dataPcm = new Int16[samplesRecorded];
for (int i = 0; i < samplesRecorded; i++)
{
dataPcm[i] = BitConverter.ToInt16(args.Buffer, i * bytesPerSample);
}
// the PCM size to be analyzed with FFT must be a power of 2
int fftPoints = 2;
while (fftPoints * 2 <= dataPcm.Length)
{
fftPoints *= 2;
}
// apply a Hamming window function as we load the FFT array then calculate the FFT
NAudio.Dsp.Complex[] fftFull = new NAudio.Dsp.Complex[fftPoints];
for (int i = 0; i < fftPoints; i++)
{
fftFull[i].X = (float)(dataPcm[i] * NAudio.Dsp.FastFourierTransform.HammingWindow(i, fftPoints));
}
NAudio.Dsp.FastFourierTransform.FFT(true, (int)Math.Log(fftPoints, 2.0), fftFull);
double[] dataFft = new double[fftPoints / 2];
byte[] data = new byte[fftPoints / 2];
for (int i = 0; i < fftPoints / 2; i++)
{
double fftLeft = Math.Abs(fftFull[i].X + fftFull[i].Y);
double fftRight = Math.Abs(fftFull[fftPoints - i - 1].X + fftFull[fftPoints - i - 1].Y);
dataFft[i] = fftLeft + fftRight;
data[i] = (byte)(fftLeft + fftRight);
}
/*if(SpectrumVisualizer.GetType().Name == "CircleSpectrumVisualizer")
* SpectrumVisualizer.Set(GetNiceCircleFFT(data));
* else
* SpectrumVisualizer.Set(data);*/
SpectrumVisualizer.Set(GetNiceFftData(data, SpectrumVisualizer.GetType().Name == "CircleSpectrumVisualizer"));
}
public static void NAaudioFFTTestUsingDouble(string CSVFilePath=null, double[] audio_data=null, int testLoopCount=1)
{
if (audio_data == null) {
audio_data = GetSignalTestData();
}
int windowLength = audio_data.Length;
int binaryExponentitation = (int)Math.Log(windowLength, 2);
NAudio.Dsp.Complex[] complexArray = new NAudio.Dsp.Complex[windowLength];
for (int i = 0; i < windowLength; i++) {
complexArray[i].X = (float) audio_data[i];
complexArray[i].Y = 0;
}
// loop if neccesary - e.g. for performance test purposes
for (int i = 0; i < testLoopCount; i++) {
// perform the FFT
NAudio.Dsp.FastFourierTransform.FFT(true, binaryExponentitation, complexArray);
}
// get the result
double[] spectrum_fft_real = new double[complexArray.Length];
double[] spectrum_fft_imag = new double[complexArray.Length];
double[] spectrum_fft_abs = new double[complexArray.Length];
for (int i = 0; i < complexArray.Length; i++) {
float re = complexArray[i].X;
float img = complexArray[i].Y;
spectrum_fft_real[i] = re * windowLength;
spectrum_fft_imag[i] = img * windowLength;
spectrum_fft_abs[i] = (float) Math.Sqrt(re*re + img*img) * windowLength;
}
// perform the inverse FFT (IFFT)
NAudio.Dsp.FastFourierTransform.FFT(false, binaryExponentitation, complexArray);
// get the result
double[] spectrum_inverse_real = new double[complexArray.Length];
double[] spectrum_inverse_imag = new double[complexArray.Length];
double[] spectrum_inverse_abs = new double[complexArray.Length];
for (int i = 0; i < complexArray.Length; i++) {
float re = complexArray[i].X;
float img = complexArray[i].Y;
spectrum_inverse_real[i] = re;
spectrum_inverse_imag[i] = img;
spectrum_inverse_abs[i] = (float) Math.Sqrt(re*re + img*img);
}
if (CSVFilePath!=null) {
CommonUtils.Export.exportCSV(CSVFilePath, audio_data, spectrum_fft_real, spectrum_fft_imag, spectrum_fft_abs, spectrum_inverse_real, spectrum_inverse_imag, spectrum_inverse_abs);
}
}
public void DrawVisualizerTimer(object sender, EventArgs e)
{
if (buffer == null)
{
Console.WriteLine("No buffer available");
return;
}
int len = buffer.FloatBuffer.Length / 8;
int M = 6;
// fft
NAudio.Dsp.Complex[] values = new NAudio.Dsp.Complex[len];
for (int i = 0; i < len; i++)
{
values[i].Y = 0;
values[i].X = buffer.FloatBuffer[i];
}
NAudio.Dsp.FastFourierTransform.FFT(true, M, values);
double scale = 0;
for (int i = 0; i < Math.Pow(2, M) / 2; i++)
{
//Console.Write(" " + values[i].X.ToString("N2"));
scale += values[i].X;
}
if (scale < 0)
{
scale *= -1;
}
audioScale = scale * 5;
//Console.WriteLine(" > " + scale);
if (audioScale > 0)
{
outterFireScaleTransform.BeginAnimation(ScaleTransform.ScaleXProperty, new DoubleAnimation(1, 1 + audioScale, TimeSpan.FromMilliseconds(100)));
outterFireScaleTransform.BeginAnimation(ScaleTransform.ScaleYProperty, new DoubleAnimation(1, 1 + audioScale, TimeSpan.FromMilliseconds(100)));
outterFireScaleTransform.BeginAnimation(ScaleTransform.ScaleXProperty, new DoubleAnimation(1 + audioScale, 1, TimeSpan.FromMilliseconds(100)));
outterFireScaleTransform.BeginAnimation(ScaleTransform.ScaleYProperty, new DoubleAnimation(1 + audioScale, 1, TimeSpan.FromMilliseconds(100)));
}
if (audioScale > 0.05)
{
if (!faceControlTimer.IsEnabled)
{
String leftBefore = (String)leftEye.Content;
String rightBefore = (String)rightEye.Content;
leftEye.Content = "^";
rightEye.Content = "^";
faceControlTimer = new DispatcherTimer {
Interval = TimeSpan.FromSeconds(2)
};
faceControlTimer.Start();
faceControlTimer.Tick += (s, args) =>
{
faceControlTimer.Stop();
leftEye.Content = leftBefore;
rightEye.Content = rightBefore;
};
}
}
}
