/* ssql.h
This file is part of a program that implements a Software-Defined Radio.
Copyright (C) 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@pratt.one
*/
#ifndef wdsp_ssql_h
#define wdsp_ssql_h
#include "export.h"
namespace WDSP {
class WDSP_API FTOV // Frequency to Voltage Converter
{
public:
int run; // 0 => don't run; 1 => run
int size; // buffer size
int rate; // sample-rate
int rsize; // rate * time_to_fill_ring, e.g., 48K/s * 50ms = 2400
double fmax; // frequency (Hz) for full output, e.g., 2000 (Hz)
float* in; // pointer to the intput buffer for ftov
float* out; // pointer to the output buffer for ftov
int* ring; // pointer to the base of the ring
int rptr; // index into the ring
double inlast; // holds last sample from previous buffer
int rcount; // count of zero-crossings currently in the ring
double div; // divisor for 'rcount' to produce output of 1.0 at 'fmax'
double eps; // minimum input change to count as a signal edge transition
static FTOV* create_ftov (int run, int size, int rate, int rsize, double fmax, float* in, float* out);
static void destroy_ftov (FTOV *a);
static void flush_ftov (FTOV *a);
static void xftov (FTOV *a);
};
class CBL;
class FTDV;
class BQLP;
class RXA;
class WDSP_API SSQL // Syllabic Squelch
{
public:
int run; // 0 if squelch system is OFF; 1 if it's ON
int size; // size of input/output buffers
float* in; // squelch input signal buffer
float* out; // squelch output signal buffer
int rate; // sample rate
int state; // state machine control
int count; // count variable for raised cosine transitions
double tup; // time for turn-on transition
double tdown; // time for turn-off transition
int ntup; // number of samples for turn-on transition
int ntdown; // number of samples for turn-off transition
float* cup; // coefficients for up-slew
float* cdown; // coefficients for down-slew
double muted_gain; // audio gain while muted; 0.0 for complete silence
float* b1; // buffer to hold output of dc-block function
float* ibuff; // buffer containing only 'I' component
float* ftovbuff; // buffer containing output of f to v converter
float* lpbuff; // buffer containing output of low-pass filter
int* wdbuff; // buffer containing output of window detector
CBL *dcbl; // pointer to DC Blocker data structure
FTOV *cvtr; // pointer to F to V Converter data structure
BQLP *filt; // pointer to Bi-Quad Low-Pass Filter data structure
int ftov_rsize; // ring size for f_to_v converter
double ftov_fmax; // fmax for f_to_v converter
// window detector
double wdtau; // window detector time constant
double wdmult; // window detector time constant multiplier
double wdaverage; // average signal value
double wthresh; // window threshold above/below average
// trigger
double tr_thresh; // trigger threshold: 100K/(100K+22K)=0.8197
double tr_tau_unmute; // trigger unmute time-constant: (100K||220K)*10uF = 0.6875
double tr_ss_unmute; // trigger steady-state level for unmute: 100K/(100K+220K)=0.3125
double tr_tau_mute; // trigger mute time-constant: 220K*10uF = 2.2
double tr_ss_mute; // trigger steady-state level for mute: 1.0
double tr_voltage; // trigger voltage
double mute_mult; // multiplier for successive voltage calcs when muted
double unmute_mult; // multiplier for successive voltage calcs when unmuted
int* tr_signal; // trigger signal, 0 or 1
static SSQL* create_ssql (
int run,
int size,
float* in,
float* out,
int rate,
double tup,
double tdown,
double muted_gain,
double tau_mute,
double tau_unmute,
double wthresh,
double tr_thresh,
int rsize,
double fmax
);
static void destroy_ssql (SSQL *a);
static void flush_ssql (SSQL *a);
static void xssql (SSQL *a);
static void setBuffers_ssql (SSQL *a, float* in, float* out);
static void setSamplerate_ssql (SSQL *a, int rate);
static void setSize_ssql (SSQL *a, int size);
// RXA Properties
static void SetSSQLRun (RXA& rxa, int run);
static void SetSSQLThreshold (RXA& rxa, double threshold);
static void SetSSQLTauMute (RXA& rxa, double tau_mute);
static void SetSSQLTauUnMute (RXA& rxa, double tau_unmute);
private:
static void compute_ssql_slews(SSQL *a);
static void calc_ssql (SSQL *a);
static void decalc_ssql (SSQL *a);
};
} // namespace WDSP
#endif