kopia lustrzana https://github.com/f4exb/sdrangel
137 wiersze
3.8 KiB
C++
137 wiersze
3.8 KiB
C++
/* iir.c
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This file is part of a program that implements a Software-Defined Radio.
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Copyright (C) 2014, 2022, 2023 Warren Pratt, NR0V
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Copyright (C) 2024 Edouard Griffiths, F4EXB Adapted to SDRangel
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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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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The author can be reached by email at
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warren@wpratt.com
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*/
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#include "comm.hpp"
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#include "snotch.hpp"
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#include "RXA.hpp"
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#include "TXA.hpp"
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namespace WDSP {
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/********************************************************************************************************
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* *
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* Bi-Quad Notch *
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* *
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********************************************************************************************************/
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void SNOTCH::calc_snotch (SNOTCH *a)
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{
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double fn, qk, qr, csn;
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fn = a->f / (float)a->rate;
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csn = cos (TWOPI * fn);
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qr = 1.0 - 3.0 * a->bw;
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qk = (1.0 - 2.0 * qr * csn + qr * qr) / (2.0 * (1.0 - csn));
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a->a0 = + qk;
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a->a1 = - 2.0 * qk * csn;
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a->a2 = + qk;
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a->b1 = + 2.0 * qr * csn;
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a->b2 = - qr * qr;
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flush_snotch (a);
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}
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SNOTCH* SNOTCH::create_snotch (int run, int size, float* in, float* out, int rate, double f, double bw)
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{
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SNOTCH *a = new SNOTCH;
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a->run = run;
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a->size = size;
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a->in = in;
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a->out = out;
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a->rate = rate;
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a->f = f;
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a->bw = bw;
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calc_snotch (a);
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return a;
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}
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void SNOTCH::destroy_snotch (SNOTCH *a)
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{
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delete (a);
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}
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void SNOTCH::flush_snotch (SNOTCH *a)
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{
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a->x1 = a->x2 = a->y1 = a->y2 = 0.0;
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}
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void SNOTCH::xsnotch (SNOTCH *a)
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{
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if (a->run)
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{
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int i;
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for (i = 0; i < a->size; i++)
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{
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a->x0 = a->in[2 * i + 0];
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a->out[2 * i + 0] = a->a0 * a->x0 + a->a1 * a->x1 + a->a2 * a->x2 + a->b1 * a->y1 + a->b2 * a->y2;
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a->y2 = a->y1;
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a->y1 = a->out[2 * i + 0];
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a->x2 = a->x1;
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a->x1 = a->x0;
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}
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}
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else if (a->out != a->in)
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{
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std::copy( a->in, a->in + a->size * 2, a->out);
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}
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}
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void SNOTCH::setBuffers_snotch (SNOTCH *a, float* in, float* out)
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{
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a->in = in;
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a->out = out;
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}
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void SNOTCH::setSamplerate_snotch (SNOTCH *a, int rate)
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{
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a->rate = rate;
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calc_snotch (a);
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}
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void SNOTCH::setSize_snotch (SNOTCH *a, int size)
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{
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a->size = size;
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flush_snotch (a);
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}
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/********************************************************************************************************
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* *
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* RXA Properties *
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* *
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********************************************************************************************************/
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void SNOTCH::SetSNCTCSSFreq (SNOTCH *a, double freq)
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{
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a->f = freq;
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calc_snotch (a);
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}
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void SNOTCH::SetSNCTCSSRun (SNOTCH *a, int run)
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{
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a->run = run;
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}
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} // namespace WDSP
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