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130 lines
3.4 KiB
C++
130 lines
3.4 KiB
C++
///////////////////////////////////////////////////////////////////////////////////
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// Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
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// written by Christian Daniel //
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// Copyright (C) 2019-2020, 2022 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
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// //
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// This program is free software; you can redistribute it and/or modify //
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// it under the terms of the GNU General Public License as published by //
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// the Free Software Foundation as version 3 of the License, or //
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// (at your option) any later version. //
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// //
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// This program is distributed in the hope that it will be useful, //
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// but WITHOUT ANY WARRANTY; without even the implied warranty of //
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
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// GNU General Public License V3 for more details. //
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// //
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// You should have received a copy of the GNU General Public License //
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// along with this program. If not, see <http://www.gnu.org/licenses/>. //
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///////////////////////////////////////////////////////////////////////////////////
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#include "dsp/fftwindow.h"
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FFTWindow::FFTWindow() :
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m_kaiserAlpha(M_PI) // first sidelobe at < -70dB
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{
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m_kaiserI0Alpha = zeroethOrderBessel(m_kaiserAlpha);
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}
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void FFTWindow::setKaiserAlpha(Real alpha)
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{
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m_kaiserAlpha = alpha;
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m_kaiserI0Alpha = zeroethOrderBessel(m_kaiserAlpha);
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}
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void FFTWindow::setKaiserBeta(Real beta)
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{
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m_kaiserAlpha = beta / M_PI;
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m_kaiserI0Alpha = zeroethOrderBessel(m_kaiserAlpha);
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}
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void FFTWindow::create(Function function, int n)
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{
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Real (*wFunc)(Real n, Real i);
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m_window.clear();
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if (function == Kaiser) // Kaiser special case
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{
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for(int i = 0; i < n; i++) {
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m_window.push_back(kaiser(n, i));
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}
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return;
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}
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switch (function) {
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case Flattop:
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wFunc = flatTop;
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break;
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case Bartlett:
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wFunc = bartlett;
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break;
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case BlackmanHarris:
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wFunc = blackmanHarris;
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break;
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case Hamming:
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wFunc = hamming;
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break;
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case Hanning:
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wFunc = hanning;
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break;
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case Blackman:
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wFunc = blackman;
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break;
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case BlackmanHarris7:
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wFunc = blackmanHarris7;
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break;
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case Rectangle:
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default:
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wFunc = rectangle;
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break;
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}
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for(int i = 0; i < n; i++) {
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m_window.push_back(wFunc(n, i));
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}
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}
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void FFTWindow::apply(const std::vector<Real>& in, std::vector<Real>* out)
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{
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for(size_t i = 0; i < m_window.size(); i++) {
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(*out)[i] = in[i] * m_window[i];
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}
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}
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void FFTWindow::apply(const std::vector<Complex>& in, std::vector<Complex>* out)
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{
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for(size_t i = 0; i < m_window.size(); i++) {
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(*out)[i] = in[i] * m_window[i];
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}
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}
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void FFTWindow::apply(std::vector<Complex>& in)
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{
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for(size_t i = 0; i < m_window.size(); i++) {
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in[i] *= m_window[i];
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}
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}
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void FFTWindow::apply(const Complex* in, Complex* out)
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{
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for(size_t i = 0; i < m_window.size(); i++) {
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out[i] = in[i] * m_window[i];
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}
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}
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void FFTWindow::apply(Complex* in)
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{
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for(size_t i = 0; i < m_window.size(); i++) {
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in[i] *= m_window[i];
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}
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}
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