mirror of
https://github.com/cmosher01/Epple-II.git
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44 lines
1.4 KiB
C++
44 lines
1.4 KiB
C++
/*
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epple2
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Copyright (C) 2008 by Christopher A. Mosher <cmosher01@gmail.com>
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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, either version 3 of the License, or
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(at your option) any later version.
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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 for more details.
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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 "filterchroma.h"
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/*
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Generated by the utility at http://www-users.cs.york.ac.uk/~fisher/mkfilter
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3rd order low-pass Butterworth filter at 1500000 Hz.
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(sample rate 14318182 Hz)
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*/
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#define GAIN 4.910093226e+01
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FilterChroma::FilterChroma() {
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xv[0]=xv[1]=xv[2]=xv[3]=0;
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yv[0]=yv[1]=yv[2]=yv[3]=0;
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}
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FilterChroma::~FilterChroma() {
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}
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float FilterChroma::next(const float v) {
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xv[0] = xv[1]; xv[1] = xv[2]; xv[2] = xv[3];
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xv[3] = v / GAIN;
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yv[0] = yv[1]; yv[1] = yv[2]; yv[2] = yv[3];
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yv[3] = (xv[0] + xv[3]) + 3 * (xv[1] + xv[2])
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+ ( 0.2608994296 * yv[0]) + ( -1.1262209208 * yv[1])
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+ ( 1.7023917944 * yv[2]);
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return yv[3];
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}
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