kopia lustrzana https://github.com/f4exb/sdrangel
361 wiersze
9.6 KiB
C++
361 wiersze
9.6 KiB
C++
/* resample.c
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This file is part of a program that implements a Software-Defined Radio.
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Copyright (C) 2013 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 "fir.hpp"
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#include "resample.hpp"
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namespace WDSP {
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/************************************************************************************************
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* *
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* VERSION FOR COMPLEX DOUBLE-PRECISION *
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* *
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************************************************************************************************/
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void RESAMPLE::calc_resample (RESAMPLE *a)
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{
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int x, y, z;
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int i, j, k;
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int min_rate;
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float full_rate;
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float fc_norm_high, fc_norm_low;
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float* impulse;
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a->fc = a->fcin;
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a->ncoef = a->ncoefin;
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x = a->in_rate;
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y = a->out_rate;
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while (y != 0)
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{
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z = y;
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y = x % y;
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x = z;
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}
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a->L = a->out_rate / x;
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a->M = a->in_rate / x;
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if (a->in_rate < a->out_rate) min_rate = a->in_rate;
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else min_rate = a->out_rate;
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if (a->fc == 0.0) a->fc = 0.45 * (float)min_rate;
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full_rate = (float)(a->in_rate * a->L);
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fc_norm_high = a->fc / full_rate;
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if (a->fc_low < 0.0)
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fc_norm_low = - fc_norm_high;
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else
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fc_norm_low = a->fc_low / full_rate;
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if (a->ncoef == 0) a->ncoef = (int)(140.0 * full_rate / min_rate);
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a->ncoef = (a->ncoef / a->L + 1) * a->L;
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a->cpp = a->ncoef / a->L;
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a->h = new float[a->ncoef]; // (float *)malloc0(a->ncoef * sizeof(float));
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impulse = FIR::fir_bandpass(a->ncoef, fc_norm_low, fc_norm_high, 1.0, 1, 0, a->gain * (float)a->L);
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i = 0;
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for (j = 0; j < a->L; j++)
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for (k = 0; k < a->ncoef; k += a->L)
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a->h[i++] = impulse[j + k];
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a->ringsize = a->cpp;
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a->ring = new float[a->ringsize]; // (float *)malloc0(a->ringsize * sizeof(complex));
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a->idx_in = a->ringsize - 1;
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a->phnum = 0;
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delete[] (impulse);
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}
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void RESAMPLE::decalc_resample (RESAMPLE *a)
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{
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delete[] (a->ring);
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delete[] (a->h);
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}
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RESAMPLE* RESAMPLE::create_resample ( int run, int size, float* in, float* out, int in_rate, int out_rate, float fc, int ncoef, float gain)
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{
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RESAMPLE *a = new RESAMPLE;
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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->in_rate = in_rate;
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a->out_rate = out_rate;
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a->fcin = fc;
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a->fc_low = -1.0; // could add to create_resample() parameters
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a->ncoefin = ncoef;
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a->gain = gain;
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calc_resample (a);
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return a;
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}
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void RESAMPLE::destroy_resample (RESAMPLE *a)
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{
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decalc_resample (a);
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delete (a);
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}
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void RESAMPLE::flush_resample (RESAMPLE *a)
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{
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memset (a->ring, 0, a->ringsize * sizeof (wcomplex));
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a->idx_in = a->ringsize - 1;
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a->phnum = 0;
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}
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int RESAMPLE::xresample (RESAMPLE *a)
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{
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int outsamps = 0;
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if (a->run)
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{
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int i, j, n;
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int idx_out;
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float I, Q;
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for (i = 0; i < a->size; i++)
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{
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a->ring[2 * a->idx_in + 0] = a->in[2 * i + 0];
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a->ring[2 * a->idx_in + 1] = a->in[2 * i + 1];
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while (a->phnum < a->L)
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{
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I = 0.0;
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Q = 0.0;
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n = a->cpp * a->phnum;
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for (j = 0; j < a->cpp; j++)
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{
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if ((idx_out = a->idx_in + j) >= a->ringsize) idx_out -= a->ringsize;
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I += a->h[n + j] * a->ring[2 * idx_out + 0];
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Q += a->h[n + j] * a->ring[2 * idx_out + 1];
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}
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a->out[2 * outsamps + 0] = I;
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a->out[2 * outsamps + 1] = Q;
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outsamps++;
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a->phnum += a->M;
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}
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a->phnum -= a->L;
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if (--a->idx_in < 0) a->idx_in = a->ringsize - 1;
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}
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}
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else if (a->in != a->out)
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memcpy (a->out, a->in, a->size * sizeof (wcomplex));
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return outsamps;
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}
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void RESAMPLE::setBuffers_resample(RESAMPLE *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 RESAMPLE::setSize_resample(RESAMPLE *a, int size)
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{
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a->size = size;
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flush_resample (a);
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}
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void RESAMPLE::setInRate_resample(RESAMPLE *a, int rate)
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{
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decalc_resample (a);
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a->in_rate = rate;
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calc_resample (a);
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}
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void RESAMPLE::setOutRate_resample(RESAMPLE *a, int rate)
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{
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decalc_resample (a);
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a->out_rate = rate;
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calc_resample (a);
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}
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void RESAMPLE::setFCLow_resample (RESAMPLE *a, float fc_low)
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{
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if (fc_low != a->fc_low)
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{
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decalc_resample (a);
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a->fc_low = fc_low;
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calc_resample (a);
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}
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}
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void RESAMPLE::setBandwidth_resample (RESAMPLE *a, float fc_low, float fc_high)
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{
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if (fc_low != a->fc_low || fc_high != a->fcin)
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{
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decalc_resample (a);
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a->fc_low = fc_low;
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a->fcin = fc_high;
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calc_resample (a);
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}
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}
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// exported calls
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void* RESAMPLE::create_resampleV (int in_rate, int out_rate)
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{
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return (void *)create_resample (1, 0, 0, 0, in_rate, out_rate, 0.0, 0, 1.0);
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}
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void RESAMPLE::xresampleV (float* input, float* output, int numsamps, int* outsamps, void* ptr)
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{
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RESAMPLE *a = (RESAMPLE*) ptr;
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a->in = input;
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a->out = output;
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a->size = numsamps;
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*outsamps = xresample(a);
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}
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void RESAMPLE::destroy_resampleV (void* ptr)
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{
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destroy_resample ( (RESAMPLE*) ptr );
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}
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/************************************************************************************************
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* *
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* VERSION FOR NON-COMPLEX FLOATS *
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* *
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************************************************************************************************/
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RESAMPLEF* RESAMPLEF::create_resampleF ( int run, int size, float* in, float* out, int in_rate, int out_rate)
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{
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RESAMPLEF *a = new RESAMPLEF;
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int x, y, z;
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int i, j, k;
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int min_rate;
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float full_rate;
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float fc;
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float fc_norm;
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float* impulse;
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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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x = in_rate;
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y = out_rate;
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while (y != 0)
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{
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z = y;
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y = x % y;
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x = z;
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}
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a->L = out_rate / x;
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a->M = in_rate / x;
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if (in_rate < out_rate) min_rate = in_rate;
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else min_rate = out_rate;
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fc = 0.45 * (float)min_rate;
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full_rate = (float)(in_rate * a->L);
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fc_norm = fc / full_rate;
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a->ncoef = (int)(60.0 / fc_norm);
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a->ncoef = (a->ncoef / a->L + 1) * a->L;
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a->cpp = a->ncoef / a->L;
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a->h = new float[a->ncoef]; // (float *) malloc0 (a->ncoef * sizeof (float));
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impulse = FIR::fir_bandpass (a->ncoef, -fc_norm, +fc_norm, 1.0, 1, 0, (float)a->L);
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i = 0;
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for (j = 0; j < a->L; j ++)
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for (k = 0; k < a->ncoef; k += a->L)
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a->h[i++] = impulse[j + k];
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a->ringsize = a->cpp;
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a->ring = new float[a->ringsize]; //(float *) malloc0 (a->ringsize * sizeof (float));
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a->idx_in = a->ringsize - 1;
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a->phnum = 0;
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delete[] (impulse);
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return a;
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}
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void RESAMPLEF::destroy_resampleF (RESAMPLEF *a)
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{
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delete[] (a->ring);
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delete[] (a->h);
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delete (a);
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}
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void RESAMPLEF::flush_resampleF (RESAMPLEF *a)
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{
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memset (a->ring, 0, a->ringsize * sizeof (float));
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a->idx_in = a->ringsize - 1;
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a->phnum = 0;
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}
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int RESAMPLEF::xresampleF (RESAMPLEF *a)
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{
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int outsamps = 0;
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if (a->run)
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{
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int i, j, n;
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int idx_out;
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float I;
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for (i = 0; i < a->size; i++)
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{
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a->ring[a->idx_in] = (float)a->in[i];
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while (a->phnum < a->L)
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{
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I = 0.0;
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n = a->cpp * a->phnum;
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for (j = 0; j < a->cpp; j++)
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{
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if ((idx_out = a->idx_in + j) >= a->ringsize) idx_out -= a->ringsize;
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I += a->h[n + j] * a->ring[idx_out];
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}
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a->out[outsamps] = (float)I;
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outsamps++;
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a->phnum += a->M;
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}
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a->phnum -= a->L;
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if (--a->idx_in < 0) a->idx_in = a->ringsize - 1;
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}
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}
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else if (a->in != a->out)
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memcpy (a->out, a->in, a->size * sizeof (float));
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return outsamps;
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}
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// Exported calls
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void* RESAMPLEF::create_resampleFV (int in_rate, int out_rate)
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{
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return (void *) create_resampleF (1, 0, 0, 0, in_rate, out_rate);
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}
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void RESAMPLEF::xresampleFV (float* input, float* output, int numsamps, int* outsamps, void* ptr)
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{
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RESAMPLEF *a = (RESAMPLEF*) ptr;
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a->in = input;
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a->out = output;
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a->size = numsamps;
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*outsamps = xresampleF(a);
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}
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void RESAMPLEF::destroy_resampleFV (void* ptr)
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{
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destroy_resampleF ( (RESAMPLEF*) ptr );
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}
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} // namespace WDSP
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