sdrangel/wdsp/osctrl.cpp

/*  osctrl.c

This file is part of a program that implements a Software-Defined Radio.

Copyright (C) 2014, 2017 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

*/

// This file is part of the implementation of the Overshoot Controller from
// "Controlled Envelope Single Sideband" by David L. Hershberger, W9GR, in
// the November/December 2014 issue of QEX.

#include "comm.hpp"
#include "osctrl.hpp"
#include "TXA.hpp"

namespace WDSP {

void OSCTRL::calc_osctrl (OSCTRL *a)
{
    a->pn = (int)((0.3 / a->bw) * a->rate + 0.5);
    if ((a->pn & 1) == 0) a->pn += 1;
    if (a->pn < 3) a->pn = 3;
    a->dl_len = a->pn >> 1;
    a->dl    = new float[a->pn * 2]; // (float *) malloc0 (a->pn * sizeof (complex));
    a->dlenv = new float[a->pn]; // (float *) malloc0 (a->pn * sizeof (float));
    a->in_idx = 0;
    a->out_idx = a->in_idx + a->dl_len;
    a->max_env = 0.0;
}

void OSCTRL::decalc_osctrl (OSCTRL *a)
{
    delete[] (a->dlenv);
    delete[] (a->dl);
}

OSCTRL* OSCTRL::create_osctrl (
    int run,
    int size,
    float* inbuff,
    float* outbuff,
    int rate,
    float osgain
)
{
    OSCTRL *a = new OSCTRL;
    a->run = run;
    a->size = size;
    a->inbuff = inbuff;
    a->outbuff = outbuff;
    a->rate = rate;
    a->osgain = osgain;
    a->bw = 3000.0;
    calc_osctrl (a);
    return a;
}

void OSCTRL::destroy_osctrl (OSCTRL *a)
{
    decalc_osctrl (a);
    delete (a);
}

void OSCTRL::flush_osctrl (OSCTRL *a)
{
    std::fill(a->dl, a->dl + a->dl_len * 2, 0);
    std::fill(a->dlenv, a->dlenv + a->pn, 0);
}

void OSCTRL::xosctrl (OSCTRL *a)
{
    if (a->run)
    {
        int i, j;
        float divisor;
        for (i = 0; i < a->size; i++)
        {
            a->dl[2 * a->in_idx + 0] = a->inbuff[2 * i + 0];                            // put sample in delay line
            a->dl[2 * a->in_idx + 1] = a->inbuff[2 * i + 1];
            a->env_out = a->dlenv[a->in_idx];                                           // take env out of delay line
            a->dlenv[a->in_idx] = sqrt (a->inbuff[2 * i + 0] * a->inbuff[2 * i + 0]     // put env in delay line
                                      + a->inbuff[2 * i + 1] * a->inbuff[2 * i + 1]);
            if (a->dlenv[a->in_idx]  >  a->max_env) a->max_env = a->dlenv[a->in_idx];
            if (a->env_out >= a->max_env && a->env_out > 0.0)                           // run the buffer
            {
                a->max_env = 0.0;
                for (j = 0; j < a->pn; j++)
                    if (a->dlenv[j] > a->max_env) a->max_env = a->dlenv[j];
            }
            if (a->max_env > 1.0) divisor = 1.0 + a->osgain * (a->max_env - 1.0);
            else                  divisor = 1.0;
            a->outbuff[2 * i + 0] = a->dl[2 * a->out_idx + 0] / divisor;                // output sample
            a->outbuff[2 * i + 1] = a->dl[2 * a->out_idx + 1] / divisor;
            if (--a->in_idx  < 0) a->in_idx  += a->pn;
            if (--a->out_idx < 0) a->out_idx += a->pn;
        }
    }
    else if (a->inbuff != a->outbuff)
        std::copy(a->inbuff, a->inbuff + a->size * 2, a->outbuff);
}

void OSCTRL::setBuffers_osctrl (OSCTRL *a, float* in, float* out)
{
    a->inbuff = in;
    a->outbuff = out;
}

void OSCTRL::setSamplerate_osctrl (OSCTRL *a, int rate)
{
    decalc_osctrl (a);
    a->rate = rate;
    calc_osctrl (a);
}

void OSCTRL::setSize_osctrl (OSCTRL *a, int size)
{
    a->size = size;
    flush_osctrl (a);
}

/********************************************************************************************************
*                                                                                                       *
*                                           TXA Properties                                              *
*                                                                                                       *
********************************************************************************************************/

void OSCTRL::SetosctrlRun (TXA& txa, int run)
{
    if (txa.osctrl->run != run)
    {
        txa.osctrl->run = run;
        TXA::SetupBPFilters (txa);
    }
}

} // namespace WDSP