sdrangel/wdsp/wcpAGC.cpp

/*  wcpAGC.c

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

Copyright (C) 2011 - 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

or by paper mail at

Warren Pratt
11303 Empire Grade
Santa Cruz, CA  95060

*/

#include "comm.hpp"
#include "nbp.hpp"
#include "wcpAGC.hpp"
#include "RXA.hpp"
#include "TXA.hpp"

namespace WDSP {

void WCPAGC::calc_wcpagc (WCPAGC *a)
{
    //assign constants
    a->ring_buffsize = RB_SIZE;
    //do one-time initialization
    a->out_index = -1;
    a->ring_max = 0.0;
    a->volts = 0.0;
    a->save_volts = 0.0;
    a->fast_backaverage = 0.0;
    a->hang_backaverage = 0.0;
    a->hang_counter = 0;
    a->decay_type = 0;
    a->state = 0;
    a->ring = new double[RB_SIZE * 2]; // (float *)malloc0(RB_SIZE * sizeof(complex));
    a->abs_ring = new double[RB_SIZE]; //(float *)malloc0(RB_SIZE * sizeof(float));
    loadWcpAGC(a);
}

void WCPAGC::decalc_wcpagc (WCPAGC *a)
{
    delete[] (a->abs_ring);
    delete[] (a->ring);
}

WCPAGC* WCPAGC::create_wcpagc (
    int run,
    int mode,
    int pmode,
    float* in,
    float* out,
    int io_buffsize,
    int sample_rate,
    double tau_attack,
    double tau_decay,
    int n_tau,
    double max_gain,
    double var_gain,
    double fixed_gain,
    double max_input,
    double out_targ,
    double tau_fast_backaverage,
    double tau_fast_decay,
    double pop_ratio,
    int hang_enable,
    double tau_hang_backmult,
    double hangtime,
    double hang_thresh,
    double tau_hang_decay
)
{
    WCPAGC *a = new WCPAGC;
    //initialize per call parameters
    a->run = run;
    a->mode = mode;
    a->pmode = pmode;
    a->in = in;
    a->out = out;
    a->io_buffsize = io_buffsize;
    a->sample_rate = (float)sample_rate;
    a->tau_attack = tau_attack;
    a->tau_decay = tau_decay;
    a->n_tau = n_tau;
    a->max_gain = max_gain;
    a->var_gain = var_gain;
    a->fixed_gain = fixed_gain;
    a->max_input = max_input;
    a->out_targ = out_targ;
    a->tau_fast_backaverage = tau_fast_backaverage;
    a->tau_fast_decay = tau_fast_decay;
    a->pop_ratio = pop_ratio;
    a->hang_enable = hang_enable;
    a->tau_hang_backmult = tau_hang_backmult;
    a->hangtime = hangtime;
    a->hang_thresh = hang_thresh;
    a->tau_hang_decay = tau_hang_decay;
    calc_wcpagc (a);
    return a;
}

void WCPAGC::loadWcpAGC (WCPAGC *a)
{
    float tmp;
    //calculate internal parameters
    a->attack_buffsize = (int)ceil(a->sample_rate * a->n_tau * a->tau_attack);
    a->in_index = a->attack_buffsize + a->out_index;
    a->attack_mult = 1.0 - exp(-1.0 / (a->sample_rate * a->tau_attack));
    a->decay_mult = 1.0 - exp(-1.0 / (a->sample_rate * a->tau_decay));
    a->fast_decay_mult = 1.0 - exp(-1.0 / (a->sample_rate * a->tau_fast_decay));
    a->fast_backmult = 1.0 - exp(-1.0 / (a->sample_rate * a->tau_fast_backaverage));
    a->onemfast_backmult = 1.0 - a->fast_backmult;

    a->out_target = a->out_targ * (1.0 - exp(-(float)a->n_tau)) * 0.9999;
    a->min_volts = a->out_target / (a->var_gain * a->max_gain);
    a->inv_out_target = 1.0 / a->out_target;

    tmp = log10(a->out_target / (a->max_input * a->var_gain * a->max_gain));
    if (tmp == 0.0)
        tmp = 1e-16;
    a->slope_constant = (a->out_target * (1.0 - 1.0 / a->var_gain)) / tmp;

    a->inv_max_input = 1.0 / a->max_input;

    tmp = pow (10.0, (a->hang_thresh - 1.0) / 0.125);
    a->hang_level = (a->max_input * tmp + (a->out_target /
        (a->var_gain * a->max_gain)) * (1.0 - tmp)) * 0.637;

    a->hang_backmult = 1.0 - exp(-1.0 / (a->sample_rate * a->tau_hang_backmult));
    a->onemhang_backmult = 1.0 - a->hang_backmult;

    a->hang_decay_mult = 1.0 - exp(-1.0 / (a->sample_rate * a->tau_hang_decay));
}

void WCPAGC::destroy_wcpagc (WCPAGC *a)
{
    decalc_wcpagc (a);
    delete (a);
}

void WCPAGC::flush_wcpagc (WCPAGC *a)
{
    memset ((void *)a->ring, 0, sizeof(float) * RB_SIZE * 2);
    a->ring_max = 0.0;
    memset ((void *)a->abs_ring, 0, sizeof(float)* RB_SIZE);
}

void WCPAGC::xwcpagc (WCPAGC *a)
{
    int i, j, k;
    float mult;
    if (a->run)
    {
        if (a->mode == 0)
        {
            for (i = 0; i < a->io_buffsize; i++)
            {
                a->out[2 * i + 0] = a->fixed_gain * a->in[2 * i + 0];
                a->out[2 * i + 1] = a->fixed_gain * a->in[2 * i + 1];
            }
            return;
        }

        for (i = 0; i < a->io_buffsize; i++)
        {
            if (++a->out_index >= a->ring_buffsize)
                a->out_index -= a->ring_buffsize;
            if (++a->in_index >= a->ring_buffsize)
                a->in_index -= a->ring_buffsize;

            a->out_sample[0] = a->ring[2 * a->out_index + 0];
            a->out_sample[1] = a->ring[2 * a->out_index + 1];
            a->abs_out_sample = a->abs_ring[a->out_index];
            a->ring[2 * a->in_index + 0] = a->in[2 * i + 0];
            a->ring[2 * a->in_index + 1] = a->in[2 * i + 1];
            if (a->pmode == 0)
                a->abs_ring[a->in_index] = std::max(fabs(a->ring[2 * a->in_index + 0]), fabs(a->ring[2 * a->in_index + 1]));
            else
                a->abs_ring[a->in_index] = sqrt(a->ring[2 * a->in_index + 0] * a->ring[2 * a->in_index + 0] + a->ring[2 * a->in_index + 1] * a->ring[2 * a->in_index + 1]);

            a->fast_backaverage = a->fast_backmult * a->abs_out_sample + a->onemfast_backmult * a->fast_backaverage;
            a->hang_backaverage = a->hang_backmult * a->abs_out_sample + a->onemhang_backmult * a->hang_backaverage;

            if ((a->abs_out_sample >= a->ring_max) && (a->abs_out_sample > 0.0))
            {
                a->ring_max = 0.0;
                k = a->out_index;
                for (j = 0; j < a->attack_buffsize; j++)
                {
                    if (++k == a->ring_buffsize)
                        k = 0;
                    if (a->abs_ring[k] > a->ring_max)
                        a->ring_max = a->abs_ring[k];
                }
            }
            if (a->abs_ring[a->in_index] > a->ring_max)
                a->ring_max = a->abs_ring[a->in_index];

            if (a->hang_counter > 0)
                --a->hang_counter;

            switch (a->state)
            {
            case 0:
                {
                    if (a->ring_max >= a->volts)
                    {
                        a->volts += (a->ring_max - a->volts) * a->attack_mult;
                    }
                    else
                    {
                        if (a->volts > a->pop_ratio * a->fast_backaverage)
                        {
                            a->state = 1;
                            a->volts += (a->ring_max - a->volts) * a->fast_decay_mult;
                        }
                        else
                        {
                            if (a->hang_enable && (a->hang_backaverage > a->hang_level))
                            {
                                a->state = 2;
                                a->hang_counter = (int)(a->hangtime * a->sample_rate);
                                a->decay_type = 1;
                            }
                            else
                            {
                                a->state = 3;
                                a->volts += (a->ring_max - a->volts) * a->decay_mult;
                                a->decay_type = 0;
                            }
                        }
                    }
                    break;
                }
            case 1:
                {
                    if (a->ring_max >= a->volts)
                    {
                        a->state = 0;
                        a->volts += (a->ring_max - a->volts) * a->attack_mult;
                    }
                    else
                    {
                        if (a->volts > a->save_volts)
                        {
                            a->volts += (a->ring_max - a->volts) * a->fast_decay_mult;
                        }
                        else
                        {
                            if (a->hang_counter > 0)
                            {
                                a->state = 2;
                            }
                            else
                            {
                                if (a->decay_type == 0)
                                {
                                    a->state = 3;
                                    a->volts += (a->ring_max - a->volts) * a->decay_mult;
                                }
                                else
                                {
                                    a->state = 4;
                                    a->volts += (a->ring_max - a->volts) * a->hang_decay_mult;
                                }
                            }
                        }
                    }
                    break;
                }
            case 2:
                {
                    if (a->ring_max >= a->volts)
                    {
                        a->state = 0;
                        a->save_volts = a->volts;
                        a->volts += (a->ring_max - a->volts) * a->attack_mult;
                    }
                    else
                    {
                        if (a->hang_counter == 0)
                        {
                            a->state = 4;
                            a->volts += (a->ring_max - a->volts) * a->hang_decay_mult;
                        }
                    }
                    break;
                }
            case 3:
                {
                    if (a->ring_max >= a->volts)
                    {
                        a->state = 0;
                        a->save_volts = a->volts;
                        a->volts += (a->ring_max - a->volts) * a->attack_mult;
                    }
                    else
                    {
                        a->volts += (a->ring_max - a->volts) * a->decay_mult;
                    }
                    break;
                }
            case 4:
                {
                    if (a->ring_max >= a->volts)
                    {
                        a->state = 0;
                        a->save_volts = a->volts;
                        a->volts += (a->ring_max - a->volts) * a->attack_mult;
                    }
                    else
                    {
                        a->volts += (a->ring_max - a->volts) * a->hang_decay_mult;
                    }
                    break;
                }
            }

            if (a->volts < a->min_volts)
                a->volts = a->min_volts;
            a->gain = a->volts * a->inv_out_target;
            mult = (a->out_target - a->slope_constant * std::min (0.0, log10(a->inv_max_input * a->volts))) / a->volts;
            a->out[2 * i + 0] = a->out_sample[0] * mult;
            a->out[2 * i + 1] = a->out_sample[1] * mult;
        }
    }
    else if (a->out != a->in)
        std::copy(a->in, a->in + a->io_buffsize * 2, a->out);
}

void WCPAGC::setBuffers_wcpagc (WCPAGC *a, float* in, float* out)
{
    a->in = in;
    a->out = out;
}

void WCPAGC::setSamplerate_wcpagc (WCPAGC *a, int rate)
{
    decalc_wcpagc (a);
    a->sample_rate = rate;
    calc_wcpagc (a);
}

void WCPAGC::setSize_wcpagc (WCPAGC *a, int size)
{
    decalc_wcpagc (a);
    a->io_buffsize = size;
    calc_wcpagc (a);
}

/********************************************************************************************************
*                                                                                                       *
*                                           RXA Properties                                              *
*                                                                                                       *
********************************************************************************************************/

void WCPAGC::SetAGCMode (RXA& rxa, int mode)
{
    switch (mode)
    {
        case 0: //agcOFF
            rxa.agc.p->mode = 0;
            loadWcpAGC ( rxa.agc.p );
            break;
        case 1: //agcLONG
            rxa.agc.p->mode = 1;
            rxa.agc.p->hangtime = 2.000;
            rxa.agc.p->tau_decay = 2.000;
            loadWcpAGC ( rxa.agc.p );
            break;
        case 2: //agcSLOW
            rxa.agc.p->mode = 2;
            rxa.agc.p->hangtime = 1.000;
            rxa.agc.p->tau_decay = 0.500;
            loadWcpAGC ( rxa.agc.p );
            break;
        case 3: //agcMED
            rxa.agc.p->mode = 3;
            rxa.agc.p->hang_thresh = 1.0;
            rxa.agc.p->hangtime = 0.000;
            rxa.agc.p->tau_decay = 0.250;
            loadWcpAGC ( rxa.agc.p );
            break;
        case 4: //agcFAST
            rxa.agc.p->mode = 4;
            rxa.agc.p->hang_thresh = 1.0;
            rxa.agc.p->hangtime = 0.000;
            rxa.agc.p->tau_decay = 0.050;
            loadWcpAGC ( rxa.agc.p );
            break;
        default:
            rxa.agc.p->mode = 5;
            break;
    }
}

void WCPAGC::SetAGCAttack (RXA& rxa, int attack)
{
    rxa.agc.p->tau_attack = (float)attack / 1000.0;
    loadWcpAGC ( rxa.agc.p );
}

void WCPAGC::SetAGCDecay (RXA& rxa, int decay)
{
    rxa.agc.p->tau_decay = (float)decay / 1000.0;
    loadWcpAGC ( rxa.agc.p );
}

void WCPAGC::SetAGCHang (RXA& rxa, int hang)
{
    rxa.agc.p->hangtime = (float)hang / 1000.0;
    loadWcpAGC ( rxa.agc.p );
}

void WCPAGC::GetAGCHangLevel(RXA& rxa, float *hangLevel)
//for line on bandscope
{
    *hangLevel = 20.0 * log10( rxa.agc.p->hang_level / 0.637 );
}

void WCPAGC::SetAGCHangLevel(RXA& rxa, float hangLevel)
//for line on bandscope
{
    float convert, tmp;

    if (rxa.agc.p->max_input > rxa.agc.p->min_volts)
    {
        convert = pow (10.0, hangLevel / 20.0);
        tmp = std::max(1e-8, (convert - rxa.agc.p->min_volts) / (rxa.agc.p->max_input - rxa.agc.p->min_volts));
        rxa.agc.p->hang_thresh = 1.0 + 0.125 * log10 (tmp);
    }
    else
        rxa.agc.p->hang_thresh = 1.0;

    loadWcpAGC ( rxa.agc.p );
}

void WCPAGC::GetAGCHangThreshold(RXA& rxa, int *hangthreshold)
//for slider in setup
{
    *hangthreshold = (int)(100.0 * rxa.agc.p->hang_thresh);
}

void WCPAGC::SetAGCHangThreshold (RXA& rxa, int hangthreshold)
//For slider in setup
{
    rxa.agc.p->hang_thresh = (float)hangthreshold / 100.0;
    loadWcpAGC ( rxa.agc.p );
}

void WCPAGC::GetAGCThresh(RXA& rxa, float *thresh, float size, float rate)
//for line on bandscope.
{
    float noise_offset;
    noise_offset = 10.0 * log10((rxa.nbp0.p->fhigh - rxa.nbp0.p->flow) * size / rate);
    *thresh = 20.0 * log10( rxa.agc.p->min_volts ) - noise_offset;
}

void WCPAGC::SetAGCThresh(RXA& rxa, float thresh, float size, float rate)
//for line on bandscope
{
    float noise_offset;
    noise_offset = 10.0 * log10((rxa.nbp0.p->fhigh - rxa.nbp0.p->flow) * size / rate);
    rxa.agc.p->max_gain = rxa.agc.p->out_target / (rxa.agc.p->var_gain * pow (10.0, (thresh + noise_offset) / 20.0));
    loadWcpAGC ( rxa.agc.p );
}

void WCPAGC::GetAGCTop(RXA& rxa, float *max_agc)
//for AGC Max Gain in setup
{
    *max_agc = 20 * log10 (rxa.agc.p->max_gain);
}

void WCPAGC::SetAGCTop (RXA& rxa, float max_agc)
//for AGC Max Gain in setup
{
    rxa.agc.p->max_gain = pow (10.0, (float)max_agc / 20.0);
    loadWcpAGC ( rxa.agc.p );
}

void WCPAGC::SetAGCSlope (RXA& rxa, int slope)
{
    rxa.agc.p->var_gain = pow (10.0, (float)slope / 20.0 / 10.0);
    loadWcpAGC ( rxa.agc.p );
}

void WCPAGC::SetAGCFixed (RXA& rxa, float fixed_agc)
{
    rxa.agc.p->fixed_gain = pow (10.0, (float)fixed_agc / 20.0);
    loadWcpAGC ( rxa.agc.p );
}

void WCPAGC::SetAGCMaxInputLevel (RXA& rxa, float level)
{
    rxa.agc.p->max_input = level;
    loadWcpAGC ( rxa.agc.p );
}

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

void WCPAGC::SetALCSt (TXA& txa, int state)
{
    txa.alc.p->run = state;
}

void WCPAGC::SetALCAttack (TXA& txa, int attack)
{
    txa.alc.p->tau_attack = (float)attack / 1000.0;
    loadWcpAGC(txa.alc.p);
}

void WCPAGC::SetALCDecay (TXA& txa, int decay)
{
    txa.alc.p->tau_decay = (float)decay / 1000.0;
    loadWcpAGC(txa.alc.p);
}

void WCPAGC::SetALCHang (TXA& txa, int hang)
{
    txa.alc.p->hangtime = (float)hang / 1000.0;
    loadWcpAGC(txa.alc.p);
}

void WCPAGC::SetALCMaxGain (TXA& txa, float maxgain)
{
    txa.alc.p->max_gain = pow (10.0,(float)maxgain / 20.0);
    loadWcpAGC(txa.alc.p);
}

void WCPAGC::SetLevelerSt (TXA& txa, int state)
{
    txa.leveler.p->run = state;
}

void WCPAGC::SetLevelerAttack (TXA& txa, int attack)
{
    txa.leveler.p->tau_attack = (float)attack / 1000.0;
    loadWcpAGC(txa.leveler.p);
}

void WCPAGC::SetLevelerDecay (TXA& txa, int decay)
{
    txa.leveler.p->tau_decay = (float)decay / 1000.0;
    loadWcpAGC(txa.leveler.p);
}

void WCPAGC::SetLevelerHang (TXA& txa, int hang)
{
    txa.leveler.p->hangtime = (float)hang / 1000.0;
    loadWcpAGC(txa.leveler.p);
}

void WCPAGC::SetLevelerTop (TXA& txa, float maxgain)
{
    txa.leveler.p->max_gain = pow (10.0,(float)maxgain / 20.0);
    loadWcpAGC(txa.leveler.p);
}

} // namespace WDSP