public override void Draw(RenderWindow window)
{
if (!isFirstFrame)
{
waitForEnter();
}
else
{
isFirstFrame = false;
}
double[] samples = new double[BufferSize];
for (int i = 0; i < rendersTillStop; i++)
{
if (offset + BufferSize < SampleCount)
{
for (int counter = 0; counter < BufferSize; counter++) //one line of spectogram
{
samples[counter] = Samples[offset + counter]; //4k samples
}
offset += (int)BufferSize;
//filter out high frequencies and downsample audio data
var cutOffData = AudioProcessor.DownSample(samples, downSampleCoef, SampleRate); //1k samples
for (int index = 0; index < BufferSize / downSampleCoef; index++)
{
//data[index * 2] = cutOffData[index] * hammingWindow[index]; //apply hamming window
bins[index * 2] = cutOffData[index] * this.window[index]; //apply hamming window
bins[index * 2 + 1] = 0d; //set 0s for Img complex values
}
FastFourierTransformation.FFT(bins); //apply fft
//1024 = WIDTH 700=HEIGHT
Render(bins, new Vector2f(100 + i * (1024 / rendersTillStop), 700), (int)BufferSize / (2 * downSampleCoef));
window.Draw(VA);
}
else
{
//Draw last frame and then close window
window.Draw(instructionsText);
window.Display();
waitForEnter();
window.Close();
return;
}
}
window.Draw(instructionsText);
}
public override void Update()
{
int offset = (int)(Song.PlayingOffset.AsSeconds() * SampleRate);
timeText.DisplayedString = Song.PlayingOffset.AsSeconds().ToString();
double[] samples = new double[BufferSize]; //allocate array taht will be used at downsampling
Task t1 = Task.Factory.StartNew(() => SetImaginary());
if (offset + BufferSize < SampleCount)
{
if (ChannelCount == 2)
{
for (uint i = 0; i < BufferSize; i++)
{
samples[i] = Samples[(i + offset) * 2];
}
}
else
{
for (uint i = 0; i < BufferSize; i++)
{
samples[i] = Samples[(i + offset)];
}
}
}
//Filter out frequencies and then downsamples
var cutOffData = AudioProcessor.DownSample(samples, downSampleCoef, SampleRate);
t1.Wait(); //t1 is working with bin array
//enter complex values to the bin array
for (int i = 0; i < BufferSize / downSampleCoef; i++)
{
bin[i * 2] = cutOffData[i] * window[i];
}
FastFourierTransformation.FFT(bin);
for (uint i = 0; i < BufferSize / (2 * downSampleCoef); i++)
{
VA[i] = new Vertex(new Vector2f((float)(i * 0.5 * downSampleCoef + 100),
(float)(200 - AudioRecognitionLibrary.Tools.Arithmetics.GetComplexAbs(bin[2 * i], bin[2 * i + 1]) / 100000))); //100000 is to scale visualisation so it fits the window
}
}
private static void CalculateAutocorrelationUsingFFT(ReadOnlySpan <float> data, Span <float> acorr)
{
Span <ComplexF> dataComplex = stackalloc ComplexF[data.Length];
for (int i = 0; i < data.Length; i++)
{
dataComplex[i] = data[i]; //convert float into double
}
FastFourierTransformation.FFT(dataComplex);
for (int i = 0; i < dataComplex.Length; i++)
{
dataComplex[i] *= ComplexF.Conjugate(dataComplex[i]);
}
FastFourierTransformation.FFT(dataComplex, FftMode.Backward);
for (int i = 0; i < acorr.Length; i++)
{
acorr[i] = dataComplex[i].Real;
}
}
public void FFTTestFloat()
{
ComplexF[] array = new ComplexF[2048];
for (int i = 0; i < array.Length; i++)
{
array[i] = (float)Math.Sin(2.0 * Math.PI * i / array.Length);
}
ComplexF[] copy = new ComplexF[array.Length];
Array.Copy(array, copy, array.Length);
Span <ComplexF> span = new Span <ComplexF>(array);
FastFourierTransformation.FFT(span);
Span <ComplexF> transformed = stackalloc ComplexF[array.Length];
span.CopyTo(transformed);
FastFourierTransformation.FFT(span, FftMode.Backward);
try
{
for (int i = 0; i < array.Length; i++)
{
Assert.AreEqual(copy[i].Real, array[i].Real, -1.0 / short.MinValue);
Assert.AreEqual(copy[i].Imaginary, array[i].Imaginary, -1.0 / short.MinValue);
}
Console.WriteLine("Source,Transformed");
for (int i = 0; i < array.Length; i++)
{
Console.WriteLine($"{copy[i]}, {transformed[i]}");
}
}
catch (Exception)
{
Console.WriteLine("Expected,Actual");
for (int i = 0; i < array.Length; i++)
{
Console.WriteLine($"{copy[i]}, {array[i]}");
}
throw;
}
}
public void FftNewD() => FastFourierTransformation.FFT(testRegion.Span);