kopia lustrzana https://github.com/f4exb/sdrangel
121 wiersze
3.2 KiB
C++
121 wiersze
3.2 KiB
C++
///////////////////////////////////////////////////////////////////////////////////
|
|
// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
|
|
// written by Christian Daniel //
|
|
// //
|
|
// This program is free software; you can redistribute it and/or modify //
|
|
// it under the terms of the GNU General Public License as published by //
|
|
// the Free Software Foundation as version 3 of the License, or //
|
|
// (at your option) any later version. //
|
|
// //
|
|
// This program is distributed in the hope that it will be useful, //
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of //
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
|
|
// GNU General Public License V3 for more details. //
|
|
// //
|
|
// You should have received a copy of the GNU General Public License //
|
|
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
|
|
///////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#include "dsp/fftwindow.h"
|
|
|
|
FFTWindow::FFTWindow() :
|
|
m_kaiserAlpha(M_PI) // first sidelobe at < -70dB
|
|
{
|
|
m_kaiserI0Alpha = zeroethOrderBessel(m_kaiserAlpha);
|
|
}
|
|
|
|
void FFTWindow::setKaiserAlpha(Real alpha)
|
|
{
|
|
m_kaiserAlpha = alpha;
|
|
m_kaiserI0Alpha = zeroethOrderBessel(m_kaiserAlpha);
|
|
}
|
|
|
|
void FFTWindow::setKaiserBeta(Real beta)
|
|
{
|
|
m_kaiserAlpha = beta / M_PI;
|
|
m_kaiserI0Alpha = zeroethOrderBessel(m_kaiserAlpha);
|
|
}
|
|
|
|
void FFTWindow::create(Function function, int n)
|
|
{
|
|
Real (*wFunc)(Real n, Real i);
|
|
|
|
m_window.clear();
|
|
|
|
if (function == Kaiser) // Kaiser special case
|
|
{
|
|
for(int i = 0; i < n; i++) {
|
|
m_window.push_back(kaiser(n, i));
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
switch(function) {
|
|
case Flattop:
|
|
wFunc = flatTop;
|
|
break;
|
|
|
|
case Bartlett:
|
|
wFunc = bartlett;
|
|
break;
|
|
|
|
case BlackmanHarris:
|
|
wFunc = blackmanHarris;
|
|
break;
|
|
|
|
case Hamming:
|
|
wFunc = hamming;
|
|
break;
|
|
|
|
case Hanning:
|
|
wFunc = hanning;
|
|
break;
|
|
|
|
case Rectangle:
|
|
default:
|
|
wFunc = rectangle;
|
|
break;
|
|
}
|
|
|
|
for(int i = 0; i < n; i++) {
|
|
m_window.push_back(wFunc(n, i));
|
|
}
|
|
}
|
|
|
|
void FFTWindow::apply(const std::vector<Real>& in, std::vector<Real>* out)
|
|
{
|
|
for(size_t i = 0; i < m_window.size(); i++) {
|
|
(*out)[i] = in[i] * m_window[i];
|
|
}
|
|
}
|
|
|
|
void FFTWindow::apply(const std::vector<Complex>& in, std::vector<Complex>* out)
|
|
{
|
|
for(size_t i = 0; i < m_window.size(); i++) {
|
|
(*out)[i] = in[i] * m_window[i];
|
|
}
|
|
}
|
|
|
|
void FFTWindow::apply(std::vector<Complex>& in)
|
|
{
|
|
for(size_t i = 0; i < m_window.size(); i++) {
|
|
in[i] *= m_window[i];
|
|
}
|
|
}
|
|
|
|
void FFTWindow::apply(const Complex* in, Complex* out)
|
|
{
|
|
for(size_t i = 0; i < m_window.size(); i++) {
|
|
out[i] = in[i] * m_window[i];
|
|
}
|
|
}
|
|
|
|
void FFTWindow::apply(Complex* in)
|
|
{
|
|
for(size_t i = 0; i < m_window.size(); i++) {
|
|
in[i] *= m_window[i];
|
|
}
|
|
}
|
|
|