kopia lustrzana https://github.com/f4exb/sdrangel
152 wiersze
4.2 KiB
C++
152 wiersze
4.2 KiB
C++
/* dbqlp.c
|
|
|
|
This file is part of a program that implements a Software-Defined Radio.
|
|
|
|
Copyright (C) 2014, 2022, 2023 Warren Pratt, NR0V
|
|
Copyright (C) 2024 Edouard Griffiths, F4EXB Adapted to SDRangel
|
|
|
|
This program is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU General Public License
|
|
as published by the Free Software Foundation; either version 2
|
|
of the License, or (at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
|
|
The author can be reached by email at
|
|
|
|
warren@wpratt.com
|
|
|
|
*/
|
|
|
|
#include "comm.hpp"
|
|
#include "dbqlp.hpp"
|
|
#include "RXA.hpp"
|
|
#include "TXA.hpp"
|
|
|
|
namespace WDSP {
|
|
|
|
/********************************************************************************************************
|
|
* *
|
|
* Double Bi-Quad Low-Pass *
|
|
* *
|
|
********************************************************************************************************/
|
|
|
|
void DBQLP::calc_dbqlp(DBQLP *a)
|
|
{
|
|
float w0, cs, c, den;
|
|
w0 = TWOPI * a->fc / (float)a->rate;
|
|
cs = cos(w0);
|
|
c = sin(w0) / (2.0 * a->Q);
|
|
den = 1.0 + c;
|
|
a->a0 = 0.5 * (1.0 - cs) / den;
|
|
a->a1 = (1.0 - cs) / den;
|
|
a->a2 = 0.5 * (1.0 - cs) / den;
|
|
a->b1 = 2.0 * cs / den;
|
|
a->b2 = (c - 1.0) / den;
|
|
flush_dbqlp(a);
|
|
}
|
|
|
|
DBQLP* DBQLP::create_dbqlp(int run, int size, float* in, float* out, double rate, double fc, double Q, double gain, int nstages)
|
|
{
|
|
DBQLP *a = new DBQLP;
|
|
a->run = run;
|
|
a->size = size;
|
|
a->in = in;
|
|
a->out = out;
|
|
a->rate = rate;
|
|
a->fc = fc;
|
|
a->Q = Q;
|
|
a->gain = gain;
|
|
a->nstages = nstages;
|
|
a->x0 = new double[a->nstages]; // (float*)malloc0(a->nstages * sizeof(float));
|
|
a->x1 = new double[a->nstages]; // (float*)malloc0(a->nstages * sizeof(float));
|
|
a->x2 = new double[a->nstages]; // (float*)malloc0(a->nstages * sizeof(float));
|
|
a->y0 = new double[a->nstages]; // (float*)malloc0(a->nstages * sizeof(float));
|
|
a->y1 = new double[a->nstages]; // (float*)malloc0(a->nstages * sizeof(float));
|
|
a->y2 = new double[a->nstages]; // (float*)malloc0(a->nstages * sizeof(float));
|
|
calc_dbqlp(a);
|
|
return a;
|
|
}
|
|
|
|
void DBQLP::destroy_dbqlp(DBQLP *a)
|
|
{
|
|
delete[](a->y2);
|
|
delete[](a->y1);
|
|
delete[](a->y0);
|
|
delete[](a->x2);
|
|
delete[](a->x1);
|
|
delete[](a->x0);
|
|
delete(a);
|
|
}
|
|
|
|
void DBQLP::flush_dbqlp(DBQLP *a)
|
|
{
|
|
int i;
|
|
for (i = 0; i < a->nstages; i++)
|
|
{
|
|
a->x1[i] = a->x2[i] = a->y1[i] = a->y2[i] = 0.0;
|
|
}
|
|
}
|
|
|
|
void DBQLP::xdbqlp(DBQLP *a)
|
|
{
|
|
if (a->run)
|
|
{
|
|
int i, n;
|
|
|
|
for (i = 0; i < a->size; i++)
|
|
{
|
|
a->x0[0] = a->gain * a->in[i];
|
|
|
|
for (n = 0; n < a->nstages; n++)
|
|
{
|
|
if (n > 0)
|
|
a->x0[n] = a->y0[n - 1];
|
|
|
|
a->y0[n] = a->a0 * a->x0[n]
|
|
+ a->a1 * a->x1[n]
|
|
+ a->a2 * a->x2[n]
|
|
+ a->b1 * a->y1[n]
|
|
+ a->b2 * a->y2[n];
|
|
a->y2[n] = a->y1[n];
|
|
a->y1[n] = a->y0[n];
|
|
a->x2[n] = a->x1[n];
|
|
a->x1[n] = a->x0[n];
|
|
}
|
|
|
|
a->out[i] = a->y0[a->nstages - 1];
|
|
}
|
|
}
|
|
else if (a->out != a->in)
|
|
{
|
|
memcpy(a->out, a->in, a->size * sizeof(float));
|
|
}
|
|
}
|
|
|
|
void DBQLP::setBuffers_dbqlp(DBQLP *a, float* in, float* out)
|
|
{
|
|
a->in = in;
|
|
a->out = out;
|
|
}
|
|
|
|
void DBQLP::setSamplerate_dbqlp(DBQLP *a, int rate)
|
|
{
|
|
a->rate = rate;
|
|
calc_dbqlp(a);
|
|
}
|
|
|
|
void DBQLP::setSize_dbqlp(DBQLP *a, int size)
|
|
{
|
|
a->size = size;
|
|
flush_dbqlp(a);
|
|
}
|
|
|
|
} // namespace WDSP
|