1 // Copyright 2004 "Gilles Degottex"
3 // This file is part of "Music"
5 // "Music" is free software; you can redistribute it and/or modify
6 // it under the terms of the GNU Lesser General Public License as published by
7 // the Free Software Foundation; either version 2.1 of the License, or
8 // (at your option) any later version.
10 // "Music" is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 // GNU Lesser General Public License for more details.
15 // You should have received a copy of the GNU Lesser General Public License
16 // along with this program; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 #include "Convolution.h"
23 #include <CppAddons/CAMath.h>
29 Convolution::Convolution(double latency_factor, double gauss_factor, double ht)
32 , m_latency_factor(latency_factor)
33 , m_duration(m_latency_factor/m_freq)
34 , m_wave(int(m_duration*GetSamplingRate()))
36 // cerr << "Convolution::Convolution " << ht << endl;
37 double c = - 2.0*Math::Pi * m_freq / GetSamplingRate();
39 double u = Usefull(Win_Sinc(gauss_factor));
41 for(size_t j=0; j<m_wave.size(); j++)
42 m_wave[j] = exp(complex<double>(0.0, c*j))*double(2.0/m_wave.size()) * win_sinc(j/double(m_wave.size()), gauss_factor)/u;
43 // m_wave[j] = exp(complex<double>(0.0, c*j))*double(2.0*Math::Pi/m_wave.size()) * win_sinc(j/double(m_wave.size()), win_factor)/u;
46 void Convolution::apply(const deque<double>& buff, int start)
48 m_value = complex<double>(0.0,0.0);
50 if(buff.size()-start >= m_wave.size())
52 for(size_t i=0; i<m_wave.size(); i++)
53 m_value += m_wave[i]*buff[i+start];