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78 lines
1.5 KiB
C++
78 lines
1.5 KiB
C++
/*
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dsp/RMS.h
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Copyright 2004 Tim Goetze <tim@quitte.de>
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http://quitte.de/dsp/
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root-mean-square accumulator.
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*/
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/*
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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
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as published by the Free Software Foundation; either version 2
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of the License, or (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, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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02111-1307, USA or point your web browser to http://www.gnu.org.
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*/
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#ifndef _DSP_RMS_H_
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#define _DSP_RMS_H_
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namespace DSP {
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class RMS
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{
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protected:
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sample_t buffer[64];
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int write;
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public:
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double sum;
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RMS()
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{
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write = 0;
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reset();
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}
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void reset()
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{
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sum = 0.;
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memset (buffer, 0, sizeof (buffer));
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}
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/* caution: pass in the *squared* sample value */
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void store (sample_t x)
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{
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sum -= buffer[write];
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sum += (buffer[write] = x);
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write = (write + 1) & 63;
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}
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sample_t process (sample_t x)
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{
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store (x);
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return rms();
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}
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sample_t rms()
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{
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/* fabs it before sqrt, just in case ... */
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return sqrt (fabs (sum) / 64);
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}
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};
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} /* namespace DSP */
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#endif /* _DSP_RMS_H_ */
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