private int LrsSrcUp(float[] x, float[] y, double factor, int nx, int nwing, float lpScl, float[] imp, float[] impD, bool interp)
{
float[] xpArray = x;
int xpIndex;
float[] ypArray = y;
int ypIndex = 0;
float v;
double currentTime = _time;
double dt;
double endTime;
dt = 1.0 / factor;
endTime = currentTime + nx;
while (currentTime < endTime)
{
double leftPhase = currentTime - Math.Floor(currentTime);
double rightPhase = 1.0 - leftPhase;
xpIndex = (int)currentTime;
v = FilterKit.LrsFilterUp(imp, impD, nwing, interp, xpArray, xpIndex++, leftPhase, -1);
v += FilterKit.LrsFilterUp(imp, impD, nwing, interp, xpArray, xpIndex, rightPhase, 1);
v *= lpScl;
ypArray[ypIndex++] = v;
currentTime += dt;
}
_time = currentTime;
return(ypIndex);
}
public ReSampler(bool highQuality, double minFactor, double maxFactor)
{
if (minFactor <= 0.0 || maxFactor <= 0.0)
{
throw new ArgumentException("minFactor and maxFactor must be positive");
}
if (maxFactor < minFactor)
{
throw new ArgumentException("minFactor must be less or equal to maxFactor");
}
_minFactor = minFactor;
_maxFactor = maxFactor;
_nmult = highQuality ? 35 : 11;
_lpScl = 1.0f;
_nwing = Npc * (_nmult - 1) / 2; // # of filter coeffs in right wing
const double rolloff = 0.90;
const double beta = 6;
var imp64 = new double[_nwing];
FilterKit.LrsLpFilter(imp64, _nwing, 0.5 * rolloff, beta, Npc);
_imp = new float[_nwing];
_impD = new float[_nwing];
for (var i = 0; i < _nwing; i++)
{
_imp[i] = (float)imp64[i];
}
for (var i = 0; i < _nwing - 1; i++)
{
_impD[i] = _imp[i + 1] - _imp[i];
}
_impD[_nwing - 1] = -_imp[_nwing - 1];
var xoffMin = (int)(((_nmult + 1) / 2.0) * Math.Max(1.0, 1.0 / minFactor) + 10);
var xoffMax = (int)(((_nmult + 1) / 2.0) * Math.Max(1.0, 1.0 / maxFactor) + 10);
_xoff = Math.Max(xoffMin, xoffMax);
_xSize = Math.Max(2 * _xoff + 10, 4096);
_x = new float[_xSize + _xoff];
_xp = _xoff;
_xread = _xoff;
var ySize = (int)(_xSize * maxFactor + 2.0);
_y = new float[ySize];
_yp = 0;
_time = _xoff;
}