46 lines
1.1 KiB
C++
46 lines
1.1 KiB
C++
/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
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/*
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QM DSP library
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Centre for Digital Music, Queen Mary, University of London.
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version. See the file
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COPYING included with this distribution for more information.
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*/
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#include "SincWindow.h"
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#include <cmath>
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void
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SincWindow::init()
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{
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if (m_length < 1) {
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return;
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} else if (m_length < 2) {
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m_window.push_back(1);
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return;
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} else {
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int n0 = (m_length % 2 == 0 ? m_length/2 : (m_length - 1)/2);
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int n1 = (m_length % 2 == 0 ? m_length/2 : (m_length + 1)/2);
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double m = 2 * M_PI / m_p;
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for (int i = 0; i < n0; ++i) {
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double x = ((m_length / 2) - i) * m;
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m_window.push_back(sin(x) / x);
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}
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m_window.push_back(1.0);
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for (int i = 1; i < n1; ++i) {
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double x = i * m;
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m_window.push_back(sin(x) / x);
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}
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}
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}
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