dl-fldigi/src/feld/feld.cxx

//
//	feld.cxx  --  FELDHELL modem
//
// Copyright (C) 2006-2010
//		Dave Freese, W1HKJ
//
// This modem code owes much to the efforts of Joe Veldhuis, N8FQ
//
// Adapted from code contained in gmfsk source code distribution.
//  gmfsk Copyright (C) 2001, 2002, 2003
//  Tomi Manninen (oh2bns@sral.fi)
//  Copyright (C) 2004
//  Lawrence Glaister (ve7it@shaw.ca)
// ----------------------------------------------------------------------------
// Copyright (C) 2014
//              David Freese, W1HKJ
//
// This file is part of fldigi
//
// fldigi 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 3 of the License, or
// (at your option) any later version.
//
// fldigi 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, see <http://www.gnu.org/licenses/>.
// ----------------------------------------------------------------------------

#include <config.h>

#include <stdlib.h>
#include <stdio.h>

#include <iostream>

using namespace std;

#include "feld.h"
#include "fl_digi.h"
#include "fontdef.h"
#include "confdialog.h"
#include "qrunner.h"
#include "status.h"
#include "debug.h"

#include <FL/Fl.H>
#include <FL/Fl_Value_Slider.H>

LOG_FILE_SOURCE(debug::LOG_MODEM);

char feldmsg[80];

int feld::RxColumnLen = FELD_RX_COLUMN_LEN;
int feld::TxColumnLen = 14;

void feld::tx_init(SoundBase *sc)
{
	scard = sc;
	txcounter = 0.0;
	tx_state = PREAMBLE;
	preamble = 3;
	prevsymb = false;
	videoText();
	return;
}

void feld::rx_init()
{
	rxcounter = 0.0;
	peakhold = 0.0;
	for (int i = 0; i < 2*RxColumnLen; i++ )
		col_data[i] = 0;
	col_pointer = 0;
	peakhold = 0.0;
	minhold = 1.0;
	agc = 0.0;
	return;
}

void feld::init()
{
	modem::init();
	initKeyWaveform();
	set_scope_mode(Digiscope::BLANK);
	put_MODEstatus(mode);
}

void feld::restart()
{
	set_bandwidth(hell_bandwidth);
}

feld::~feld()
{
	if (hilbert) delete hilbert;
	if (bpfilt) delete bpfilt;
	if (bbfilt) delete bbfilt;
	if (minmaxfilt) delete minmaxfilt;
}

feld::feld(trx_mode m)
{
	double lp;
	mode = m;
	samplerate = FeldSampleRate;

	cap |= CAP_BW;

 	switch (mode) {
// Amplitude modulation modes
		case MODE_FELDHELL:
 			feldcolumnrate = 17.5;
			rxpixrate = (RxColumnLen * feldcolumnrate);
			txpixrate = (TxColumnLen * feldcolumnrate);
			downsampleinc = (double)(rxpixrate/samplerate);
			upsampleinc = (double)(txpixrate/samplerate);
			hell_bandwidth = txpixrate;
			filter_bandwidth = progdefaults.HELL_BW_FH;
			break;
		case MODE_SLOWHELL:
			feldcolumnrate = 2.1875;
			rxpixrate = (RxColumnLen * feldcolumnrate);
			txpixrate = (TxColumnLen * feldcolumnrate);
			downsampleinc = (double)(rxpixrate/samplerate);
			upsampleinc = (double)(txpixrate/samplerate);
			hell_bandwidth = txpixrate;
			filter_bandwidth = progdefaults.HELL_BW_SH;
			break;
		case MODE_HELLX5:
			feldcolumnrate = 87.5;
			rxpixrate = (RxColumnLen * feldcolumnrate);
			txpixrate = (TxColumnLen * feldcolumnrate);
			downsampleinc = (double)(rxpixrate/samplerate);
			upsampleinc = (double)(txpixrate/samplerate);
			hell_bandwidth = txpixrate;
			filter_bandwidth = progdefaults.HELL_BW_X5;
			break;
		case MODE_HELLX9:
			feldcolumnrate = 157.5;
			rxpixrate = (RxColumnLen * feldcolumnrate);
			txpixrate = (TxColumnLen * feldcolumnrate);
			downsampleinc = (double)(rxpixrate/samplerate);
			upsampleinc = (double)(txpixrate/samplerate);
			hell_bandwidth = txpixrate;
			filter_bandwidth = progdefaults.HELL_BW_X9;
			break;
// Frequency modulation modes
		case MODE_FSKHELL:
			feldcolumnrate = 17.5;
			rxpixrate = (RxColumnLen * feldcolumnrate);
			txpixrate = (TxColumnLen * feldcolumnrate);
			downsampleinc = (double)(rxpixrate/samplerate);
			upsampleinc = (double)(txpixrate/samplerate);
			hell_bandwidth = 122.5;
			phi2freq = samplerate / M_PI / (hell_bandwidth / 2.0);
			filter_bandwidth = progdefaults.HELL_BW_FSK;
			cap |= CAP_REV;
			break;
		case MODE_FSKH105:
			feldcolumnrate = 17.5;
			rxpixrate = (RxColumnLen * feldcolumnrate);
			txpixrate = (TxColumnLen * feldcolumnrate);
			downsampleinc = (double)(rxpixrate/samplerate);
			upsampleinc = (double)(txpixrate/samplerate);
			hell_bandwidth = 55;
			phi2freq = samplerate / M_PI / (hell_bandwidth / 2.0);
			filter_bandwidth = progdefaults.HELL_BW_FSK105;
			cap |= CAP_REV;
			break;
		case MODE_HELL80:
			feldcolumnrate = 35;
			rxpixrate = (RxColumnLen * feldcolumnrate);
			txpixrate = (TxColumnLen * feldcolumnrate);
			downsampleinc = (double)(rxpixrate/samplerate);
			upsampleinc = (double)(txpixrate/samplerate);
			hell_bandwidth = 300;
			phi2freq = samplerate / M_PI / (hell_bandwidth / 2.0);
			filter_bandwidth = progdefaults.HELL_BW_HELL80;
			cap |= CAP_REV;
			break;
		default :
			feldcolumnrate = 17.5;
			break;
	}
	progdefaults.HELL_BW = filter_bandwidth;

	hilbert = new C_FIR_filter();
	hilbert->init_hilbert(37, 1);

	set_bandwidth(hell_bandwidth);

	wf->redraw_marker();

	lp = filter_bandwidth / samplerate;
	bpfilt = new fftfilt(0, lp, 1024);

	bbfilt = new Cmovavg(8);
	average = new Cmovavg( static_cast<int>(500 / downsampleinc));

	minmaxfilt = new Cmovavg(120);

	blackboard = false;
	hardkeying = false;

	rxphacc = 0.0;
	txphacc = 0.0;

}

// rx section

cmplx feld::mixer(cmplx in)
{

	cmplx z;

	z = cmplx( cos(rxphacc), sin(rxphacc) );

	z = z * in;

	rxphacc -= 2.0 * M_PI * frequency / samplerate;

	if (rxphacc < 0) rxphacc += TWOPI;

	return z;
}

void feld::FSKHELL_rx(cmplx z)
{
	double f;
	double vid;
	double avg;

	f = arg(conj(prev) * z) * phi2freq;
	prev = z;
	f = bbfilt->run(f);
	avg = average->run(abs(z));

	rxcounter += downsampleinc;
	if (rxcounter < 1.0)
		return;
	rxcounter -= 1.0;

	if (avg > agc)
		agc = avg;
	else
		agc *= (1.0 - 0.01 / RxColumnLen);
	metric = CLAMP(1000*agc, 0.0, 100.0);
	display_metric(metric);

	vid = f + 0.5;
	vid = CLAMP(vid, 0.0, 1.0);
	if (mode == MODE_HELL80)
		vid = 1.0 - vid;
	if (reverse)
		vid = 1.0 - vid;
	if (blackboard)
		vid = 1.0 - vid;

	col_data[col_pointer + RxColumnLen] = (int)(vid * 255.0);
	col_pointer++;
	if (col_pointer == RxColumnLen) {
		if (metric > progStatus.sldrSquelchValue || progStatus.sqlonoff == false) {
			REQ(put_rx_data, col_data, col_data.size());
			if (!halfwidth)
				REQ(put_rx_data, col_data, col_data.size());
		}
		col_pointer = 0;
		for (int i = 0; i < RxColumnLen; i++)
			col_data[i] = col_data[i + RxColumnLen];
	}
}

void feld::rx(cmplx z)
{
	double x, avg;

	x = abs(z);
	if (x > peakval) peakval = x;
	avg = average->run(x);

	rxcounter += downsampleinc;
	if (rxcounter < 1.0)
		return;
	rxcounter -= 1.0;

	x = peakval;
	peakval = 0;
	if (x > peakhold)
		peakhold = x;
	else
		peakhold *= (1.0 - 0.02 / RxColumnLen);
	x = x / peakhold;
	x = CLAMP (x, 0.0, 1.0);

	if (avg > agc)
		agc = avg;
	else
		agc *= (1.0 - 0.01 / RxColumnLen);
	metric = CLAMP(1000*agc, 0.0, 100.0);
	display_metric(metric);

	if (blackboard)
		x = 255 * x;
	else
		x = 255 * (1.0 - x);

	col_data[col_pointer + RxColumnLen] = (int)x;
	col_pointer++;
	if (col_pointer == RxColumnLen) {
		if (metric > progStatus.sldrSquelchValue || progStatus.sqlonoff == false) {
			REQ(put_rx_data, col_data, col_data.size());
			if (!halfwidth)
				REQ(put_rx_data, col_data, col_data.size());
		}
		col_pointer = 0;
		for (int i = 0; i < RxColumnLen; i++)
			col_data[i] = col_data[i + RxColumnLen];
	}
}

int feld::rx_process(const double *buf, int len)
{

	cmplx z, *zp;
	int i, n;

	halfwidth = progdefaults.HellRcvWidth;
	blackboard = progdefaults.HellBlackboard;

	if (progdefaults.HELL_BW != filter_bandwidth) {
		double lp;
		filter_bandwidth = progdefaults.HELL_BW;
		switch (mode) {
			case MODE_FELDHELL:
				progdefaults.HELL_BW_FH = filter_bandwidth;
				break;
			case MODE_SLOWHELL:
				progdefaults.HELL_BW_SH = filter_bandwidth;
				break;
			case MODE_HELLX5:
				progdefaults.HELL_BW_X5 = filter_bandwidth;
				break;
			case MODE_HELLX9:
				progdefaults.HELL_BW_X9 = filter_bandwidth;
				break;
			case MODE_FSKHELL:
				progdefaults.HELL_BW_FSK = filter_bandwidth;
				break;
			case MODE_FSKH105:
				progdefaults.HELL_BW_FSK105 = filter_bandwidth;
				break;
			case MODE_HELL80:
				progdefaults.HELL_BW_HELL80 = filter_bandwidth;
		}

		lp = filter_bandwidth / samplerate;
		bpfilt->create_filter(0, lp);
		wf->redraw_marker();
	}

	while (len-- > 0) {
		/* create analytic signal... */
		z = cmplx( *buf, *buf );
		buf++;

		hilbert->run(z, z);

		/* ...so it can be shifted in frequency */
		z = mixer(z);

		n = bpfilt->run(z, &zp);

		switch (mode) {
			case MODE_FSKHELL:
			case MODE_FSKH105:
			case MODE_HELL80:
				for (i = 0; i < n; i++) {
					FSKHELL_rx(zp[i]);
				}
				break;
			default:
				for (i = 0; i < n; i++)
					rx(zp[i]);
				break;
		}
	}

	return 0;
}

//=====================================================================
// tx section

// returns value = column bits with b0 ... b13 the transmit rows respecfully
// 1 = on, 0 = off
// if all bits are 0
// and no lesser bits are set then character is complete
// then return -1;

int feld::get_font_data(unsigned char c, int col)
{
	int bits = 0;
	int mask;
	int bin;
	int ordbits = 0;
	fntchr *font = 0;

	if (col > 15 || c < ' ' || c > '~')
		return -1;
	mask = 1 << (15 - col);
	switch (fntnbr) {
		case 0: font = feld7x7_14; break;
		case 1: font = feld7x7n_14; break;
		case 2: font = feldDx_14; break;
		case 3: font = feldfat_14; break;
		case 4: font = feldhell_12; break;
		case 5: font = feldlittle_12; break;
		case 6: font = feldlo8_14; break;
		case 7: font = feldlow_14; break;
		case 8: font = feldmodern_14; break;
		case 9: font = feldmodern8_14; break;
		case 10: font = feldnarr_14; break;
		case 11: font = feldreal_14; break;
		case 12: font = feldstyl_14; break;
		case 13: font = feldvert_14; break;
		case 14: font = feldwide_14; break;
		default: font = feld7x7_14;
	}
	for (int i = 0; i < 14; i++) ordbits |= font[c-' '].byte[i];

	for (int row = 0; row < 14; row ++) {
		bin =  font[c - ' '].byte[13 - row] & mask;
		if ( bin != 0)
			bits |= 1 << row;
	}
	int testval = (1 << (15 - col)) - 1;
	if ( (bits == 0) && ((ordbits & testval) == 0) )
		return -1;
	return bits;
}

double feld::nco(double freq)
{
	double x = sin(txphacc);

	txphacc += 2.0 * M_PI * freq / samplerate;

	if (txphacc > TWOPI) txphacc -= TWOPI;

	return x;
}

void feld::send_symbol(int currsymb, int nextsymb)
{
	double tone = get_txfreq_woffset();
	double tone2 = 0;
	double Amp = 1.0;
	double ncoval = 0;
	int outlen = 0;

	if (mode >= MODE_FSKHELL && mode <= MODE_HELL80) {
		tone += (reverse ? -1 : 1) * (prevsymb ? -1 : 1) * bandwidth / 2.0;
		tone2 += (reverse ? -1 : 1) * (currsymb ? -1 : 1) * bandwidth / 2.0;
	}
	for (;;) {
		switch (mode) {
			ncoval = nco(tone);
			case MODE_FSKHELL : case MODE_FSKH105 : case MODE_HELL80 :
				if ((tone2 != tone) && ((1.0 - fabs(ncoval)) < .001))
					tone = tone2;
				break;
			case MODE_HELLX5 : case MODE_HELLX9 :
				Amp = currsymb;
				break;
			case MODE_FELDHELL : case MODE_SLOWHELL :
			default :
				if (prevsymb == 0 && currsymb == 1) {
					Amp = OnShape[outlen];
				} else if (currsymb == 1 && nextsymb == 0) {
					Amp = OffShape[outlen];
				} else
					Amp = currsymb;
				break;
		}
		outbuf[outlen++] = Amp * nco(tone);

		if (outlen >= OUTBUFSIZE) {
			LOG_DEBUG("feld reset");
			break;
		}
		txcounter += upsampleinc;
		if (txcounter < 1.0)
			continue;
		txcounter -= 1.0;
		break;
	}
	prevsymb = currsymb;

// write to soundcard & display
	ModulateXmtr(outbuf, outlen);
	rx_process(outbuf, outlen);

}

void feld::send_null_column()
{
	for (int i = 0; i < 14; i++)
		send_symbol(0, 0);
}

void feld::tx_char(char c)
{
	int column = 0;
	int bits, colbits;
	int currbit, nextbit;
	send_null_column();
	if (c == ' ') {
		send_null_column();
		send_null_column();
		send_null_column();
	} else {
		while ((bits = get_font_data(c, column)) != -1) {
			for (int col = 0; col < dxmode; col++) {
				colbits = bits;
				for (int i = 0; i < 14; i++) {
					currbit = colbits & 1;
					colbits = colbits >> 1;
					nextbit = colbits & 1;
					send_symbol(currbit, nextbit);
				}
			}
			column++;
		}
	}
	send_null_column();
	return;
}

int feld::tx_process()
{
	int c;
	bool hdkey;

	dxmode = progdefaults.HellXmtWidth;
	hdkey = progdefaults.HellPulseFast;

	fntnbr = progdefaults.feldfontnbr;
	if (hardkeying != hdkey) {
		hardkeying = hdkey;
		initKeyWaveform();
	}

	if (tx_state == PREAMBLE) {
		if (preamble-- > 0) {
			tx_char('.');
			return 0;
		}
		tx_state = DATA;
	}

	if (tx_state == POSTAMBLE) {
		if (postamble-- > 0) {
			tx_char('.');
			return 0;
		}
		tx_char(' ');
		tx_state = PREAMBLE;
		cwid();
		return -1;
	}

	c = get_tx_char();

	if (c == GET_TX_CHAR_ETX || stopflag) {
		tx_state = POSTAMBLE;
		postamble = 3;
		return 0;
	}

// if TX buffer empty
// send idle character
	if (c == GET_TX_CHAR_NODATA) {
		if (progdefaults.HellXmtIdle == true)
			c = '.';
		else {
			send_null_column();
			send_null_column();
			return 0;
		}
	}
	if (c == '\r' || c == '\n')
		c = ' ';

	tx_char(c);

	return 0;
}

void feld::initKeyWaveform()
{
	for (int i = 0; i < MAXLEN; i++) {
		OnShape[i] = 1.0;
		OffShape[i] = 0.0;
	}
	for (int i = 0; i < 32; i++) {
		if (hardkeying == false)
			OnShape[i] = 0.5*(1.0 - cos(M_PI * i / 33)); // raised cosine with 4 msec rise
		else if (i < 16)
			OnShape[i] = 0.5*(1.0 - cos(M_PI * i / 16)); // raised cosine with 2 msec rise
		OffShape[31 - i] = OnShape[i];
	}
}