private void SetPrePostWindow(int length)
{
if (window == null || window.Length != length)
{
var preWindow = FHTArrays.GetPreWindow(length);
var postWindow = FHTArrays.GetPostWindow(length);
window = new double[length];
for (int i = 0; i < length; i++)
{
window[i] = preWindow[i] * postWindow[i] * length * 2 * Math.Sqrt(2);
}
}
}
public void Process(short[] datain, out short[] dataout)
{
var length = datain.Length;
var mBitRev = FHTArrays.GetBitRevTable(length);
var mPreWindow = FHTArrays.GetPreWindow(length);
var mPostWindow = FHTArrays.GetPostWindow(length);
var hopanal = length / kOverlapCount;
var hopsyn = (int)(hopanal * ShiftRate);
var overlapCount = (int)Math.Ceiling((double)length / hopsyn);
var temp = new double[length];
if (shiftChanged || mLastPhase == null || mLastPhase.Length != length / 2)
{
mLastPhase = new double[length / 2];
mSumPhase = new double[length / 2];
overlap = new Overlap(overlapCount, hopsyn);
shiftChanged = false;
}
for (var i = 0; i < length; ++i)
{
var j = mBitRev[i];
var k = (uint)(j & (length - 1));
temp[i] = datain[k] * mPreWindow[k];
}
double[] re, im;
fht.ComputeFHT(temp, out re, out im);
var temp_shift = new double[length];
AnalysisAndSynthesis(ref re, ref im);
ifht.ComputeFHT(re, im, out temp_shift, false);
temp = temp_shift;
var window = FHTArrays.GetPostWindow(length);
if (overlapCount >= kOverlapCount)
{
for (var i = 0; i < length; i++)
{
temp_shift[i] *= window[i] * shiftRate / 2;
}
}
overlap.AddOverlap(ref temp_shift);
temp = new double[hopsyn];
Array.Copy(temp_shift, temp, hopsyn);
temp = Stretch(temp, 1 / ShiftRate, length);
dataout = ToShort(temp, length);
}
private void Process(short[] datain, out short[] dataout, bool isLeft)
{
FHTransform fht, ifht;
if (isLeft)
{
fht = fhtl; ifht = ifhtl;
}
else
{
fht = fhtr; ifht = ifhtr;
}
var length = datain.Length;
var mBitRev = FHTArrays.GetBitRevTable(length);
var mPreWindow = FHTArrays.GetPreWindow(length);
var mPostWindow = FHTArrays.GetPostWindow(length);
var temp = new double[length];
int freqBelowToSides = (int)((CutoffFrequency / ((double)mSampleRate / length)) + 0.5);
for (var i = 0; i < length; ++i)
{
var j = mBitRev[i];
var k = (uint)(j & (length - 1));
temp[i] = datain[k] * mPreWindow[k];
}
double[] re, im;
fht.ComputeFHT(temp, out re, out im);
for (var i = 0; i < freqBelowToSides; i++)
{
re[i] = im[i] = 0;
}
ifht.ComputeFHT(re, im, out temp, true);
dataout = ToShort(temp, length);
}
public void Processb(short[] datain, out short[] dataout)
{
// even without FFT, it works to some extent.
var length = datain.Length;
var hopanal = length / kOverlapCount;
var hopsyn = (int)(hopanal * ShiftRate);
var overlapCount = (int)Math.Ceiling((double)length / hopsyn);
if (shiftChanged || overlap == null)
{
overlap = new Overlap(overlapCount, hopsyn);
shiftChanged = false;
}
var temp_shift = new double[length];
for (var i = 0; i < length; i++)
{
temp_shift[i] = datain[i];
}
var window = FHTArrays.GetPostWindow(length);
if (overlapCount >= kOverlapCount)
{
for (var i = 0; i < length; i++)
{
temp_shift[i] *= window[i] / 2 * ShiftRate;
}
}
overlap.AddOverlap(ref temp_shift);
var temp = new double[hopsyn];
Array.Copy(temp_shift, temp, hopsyn);
temp = Stretch(temp, 1 / ShiftRate, length);
dataout = ToShort(temp, length);
}
private void Process(double[] leftin, double[] rightin, out double[] leftout, out double[] rightout)
{
int length = leftin.Length;
int freqBelowToSides = (int)((200.0 / ((double)mSampleRate / length)) + 0.5);
int freqAboveToSides = (int)((300.0 / ((double)mSampleRate / length)) + 0.5);
var mBitRev = FHTArrays.GetBitRevTable(length);
var mPreWindow = FHTArrays.GetPreWindow(length);
var mPostWindow = FHTArrays.GetPostWindow(length);
double[] tempLeft = new double[length];
double[] tempRight = new double[length];
for (uint i = 0; i < length; ++i)
{
uint j = (uint)(mBitRev[i]);
uint k = (uint)(j & (length - 1));
tempLeft[i] = leftin[k] * mPreWindow[k];
tempRight[i] = rightin[k] * mPreWindow[k];
}
fhtl.ComputeFHT(ref tempLeft, length);
fhtr.ComputeFHT(ref tempRight, length);
double[] tempC = new double[length];
for (uint i = 0; i < length / 2; i++)
{
double lR = tempLeft[i] + tempLeft[length - 1 - i];
double lI = tempLeft[i] - tempLeft[length - 1 - i];
double rR = tempRight[i] + tempRight[length - 1 - i];
double rI = tempRight[i] - tempRight[length - 1 - i];
double sumR = lR + rR;
double sumI = lI + rI;
double diffR = lR - rR;
double diffI = lI - rI;
double sumSq = sumR * sumR + sumI * sumI;
double diffSq = diffR * diffR + diffI * diffI;
double alpha = 0.0;
if (sumSq > FHTransform.nodivbyzero)
{
alpha = 0.5 - Math.Sqrt(diffSq / sumSq) * 0.5;
}
double cR = sumR * alpha;
double cI = sumI * alpha;
if (mBassToSides && ((i < freqBelowToSides)))// && (i < freqAboveToSides)))
{
cR = cI = 0.0;
}
tempC[mBitRev[i]] = cR + cI;
tempC[mBitRev[length - 1 - i]] = cR - cI;
}
fhtc.ComputeFHT(ref tempC, length, true);
for (var i = 0; i < length; i++)
{
tempLeft[i] = leftin[i] - tempC[i];
tempRight[i] = rightin[i] - tempC[i];
}
if (vocalExtract)
{
leftout = tempC;
rightout = tempC;
}
else
{
leftout = tempLeft;
rightout = tempRight;
}
}