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