//int[] chunk_freq = { 10, 100, 2048};
//int[] chunk_freq_jump = { 1, 10, 20};
private double[] FFT(double[] lastData)
{
DateTime chkpoint1 = DateTime.Now;
if (dataList == null)
{
return(null);
}
int actualN = distance2Node + 1;
if (actualN < N_FFT)
{
return(new double[0]);
}
bool transformed = false;
if (lastData == null || lastData.Length == 0)
{
lastData = new double[N_FFT];
}
else
{
transformed = true;
}
ComplexNumber[] data = new ComplexNumber[N_FFT];
var runningNode = endingNode;
for (int i = 0; i < N_FFT; i++)
{
data[i] = runningNode.Value;
if (runningNode.PrevNode == null)
{
}
runningNode = runningNode.PrevNode;
}
var result = FFTProcessor.FFT(data);
double N2 = result.Length / 2;
double[] finalresult = new double[lastData.Length];
int k = 1, transformedDataIndex = 0;
double value = 0;
double refFeq = 250;
int i_ref = (int)(refFeq * N2 / 22050);
for (int i = 0; i < N2; i += k)
{
value = 0;
//k = i / i_ref;
//k = k == 0 ? 1 : k;
var mappedFreq = i * samplingFrequency / 2 / N2;
for (int l = 0; l < chunk_freq.Length; l++)
{
if (mappedFreq < chunk_freq[l] || l == chunk_freq.Length - 1)
{
k = chunk_freq_jump[l];//chunk_freq[l] / chunk_freq[0];
break;
}
}
for (int j = i; j < i + k && j < N2; j++)
{
value += result[j].Manigtude;
}
value = value * MasterScaleFFT;
lastData[transformedDataIndex] -= lastDelay * DropOffScale;
if (Mode == 0)
{
finalresult[transformedDataIndex] = value;
}
else
{
finalresult[transformedDataIndex] = value > lastData[transformedDataIndex] ? value : lastData[transformedDataIndex];
}
transformedDataIndex++;
}
if (!transformed)
{
Array.Resize <double>(ref finalresult, transformedDataIndex);
}
DateTime chkpoint1_end = DateTime.Now;
lastDelay = chkpoint1_end.Subtract(chkpoint1).TotalMilliseconds;
osdPanel.AddSet("FFT delay(ms)", lastDelay.ToString());
return(finalresult);
}
