mirror of
https://github.com/f4exb/sdrangel.git
synced 2024-11-11 02:46:12 -05:00
150 lines
3.7 KiB
C++
150 lines
3.7 KiB
C++
/* emph.c
|
|
|
|
This file is part of a program that implements a Software-Defined Radio.
|
|
|
|
Copyright (C) 2014, 2016, 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 "emph.hpp"
|
|
#include "fcurve.hpp"
|
|
#include "fircore.hpp"
|
|
#include "TXA.hpp"
|
|
|
|
namespace WDSP {
|
|
|
|
/********************************************************************************************************
|
|
* *
|
|
* Overlap-Save FM Pre-Emphasis *
|
|
* *
|
|
********************************************************************************************************/
|
|
|
|
void EMPH::calc()
|
|
{
|
|
infilt = new float[2 * size * 2];
|
|
product = new float[2 * size * 2];
|
|
mults = FCurve::fc_mults(
|
|
size,
|
|
f_low,
|
|
f_high,
|
|
-20.0 * log10(f_high / f_low),
|
|
0.0,
|
|
ctype,
|
|
rate,
|
|
1.0 / (2.0 * size),
|
|
0,
|
|
0
|
|
);
|
|
CFor = fftwf_plan_dft_1d(2 * size, (fftwf_complex *)infilt, (fftwf_complex *)product, FFTW_FORWARD, FFTW_PATIENT);
|
|
CRev = fftwf_plan_dft_1d(2 * size, (fftwf_complex *)product, (fftwf_complex *)out, FFTW_BACKWARD, FFTW_PATIENT);
|
|
}
|
|
|
|
void EMPH::decalc()
|
|
{
|
|
fftwf_destroy_plan(CRev);
|
|
fftwf_destroy_plan(CFor);
|
|
delete[] mults;
|
|
delete[] product;
|
|
delete[] infilt;
|
|
}
|
|
|
|
EMPH::EMPH(
|
|
int _run,
|
|
int _position,
|
|
int _size,
|
|
float* _in,
|
|
float* _out,
|
|
int _rate,
|
|
int _ctype,
|
|
double _f_low,
|
|
double _f_high
|
|
) :
|
|
run(_run),
|
|
position(_position),
|
|
size(_size),
|
|
in(_in),
|
|
out(_out),
|
|
ctype(_ctype),
|
|
f_low(_f_low),
|
|
f_high(_f_high),
|
|
rate((double) _rate)
|
|
{
|
|
calc();
|
|
}
|
|
|
|
EMPH::~EMPH()
|
|
{
|
|
decalc();
|
|
}
|
|
|
|
void EMPH::flush()
|
|
{
|
|
std::fill(infilt, infilt + 2 * size * 2, 0);
|
|
}
|
|
|
|
void EMPH::execute(int _position)
|
|
{
|
|
double I;
|
|
double Q;
|
|
if (run && position == _position)
|
|
{
|
|
std::copy(in, in + size * 2, &(infilt[2 * size]));
|
|
fftwf_execute (CFor);
|
|
for (int i = 0; i < 2 * size; i++)
|
|
{
|
|
I = product[2 * i + 0];
|
|
Q = product[2 * i + 1];
|
|
product[2 * i + 0] = (float) (I * mults[2 * i + 0] - Q * mults[2 * i + 1]);
|
|
product[2 * i + 1] = (float) (I * mults[2 * i + 1] + Q * mults[2 * i + 0]);
|
|
}
|
|
fftwf_execute (CRev);
|
|
std::copy(&(infilt[2 * size]), &(infilt[2 * size]) + size * 2, infilt);
|
|
}
|
|
else if (in != out)
|
|
std::copy( in, in + size * 2, out);
|
|
}
|
|
|
|
void EMPH::setBuffers(float* _in, float* _out)
|
|
{
|
|
decalc();
|
|
in = _in;
|
|
out = _out;
|
|
calc();
|
|
}
|
|
|
|
void EMPH::setSamplerate(int _rate)
|
|
{
|
|
decalc();
|
|
rate = _rate;
|
|
calc();
|
|
}
|
|
|
|
void EMPH::setSize(int _size)
|
|
{
|
|
decalc();
|
|
size = _size;
|
|
calc();
|
|
}
|
|
|
|
} // namespace WDSP
|