RTTY decoder mods

Changed prefilter from lowpass to bandpass.
    Filter adjustment visible on both Mark & Space tones
    Increased AFC low pass filter time constant

src/cw_rtty/rtty.cxx

@@ -4,7 +4,7 @@
 // Copyright (C) 2006
 //		Dave Freese, W1HKJ
 //
-// This file is part of fldigi.  Adapted from code contained in gmfsk source code 
+// This file is part of fldigi.  Adapted from code contained in gmfsk source code
 // distribution.
 //  gmfsk Copyright (C) 2001, 2002, 2003
 //  Tomi Manninen (oh2bns@sral.fi)
@@ -120,9 +120,9 @@ void rtty::init()
 	modem::init();
 	rx_init();
 	put_MODEstatus(mode);
-	snprintf(msg1, sizeof(msg1), "Shft %-4.0f", rtty_shift); 
+	snprintf(msg1, sizeof(msg1), "Shft %-4.0f", rtty_shift);
 	put_Status1(msg1);
-	snprintf(msg2, sizeof(msg2), "Baud %-4.1f", rtty_baud); 
+	snprintf(msg2, sizeof(msg2), "Baud %-4.1f", rtty_baud);
 	put_Status2(msg2);
 	if (progdefaults.PreferXhairScope)
 		set_scope_mode(Digiscope::XHAIRS);
@@ -142,7 +142,7 @@ rtty::~rtty()
 void rtty::restart()
 {
 	double stl;
-	
+
 	rtty_shift = shift = _SHIFT[progdefaults.rtty_shift];
 	rtty_baud = _BAUD[progdefaults.rtty_baud];
 	nbits = rtty_bits = _BITS[progdefaults.rtty_bits];
@@ -163,22 +163,27 @@ void rtty::restart()
 	rxmode = LETTERS;
 	symbollen = (int) (samplerate / rtty_baud + 0.5);
 	set_bandwidth(shift);
-	
+
-    rtty_BW = shift + 3*rtty_baud;
+	rtty_BW = 0.75 * rtty_baud;
 	progdefaults.RTTY_BW = rtty_BW;
 	sldrRTTYbandwidth->value(rtty_BW);
-	
+
 	wf->redraw_marker();
 
-	if (bpfilt) 
+	bp_filt_lo = (shift/2.0 - rtty_BW) / samplerate;
-		bpfilt->create_filter(0, rtty_BW / samplerate / 2.0);
+	if (bp_filt_lo < 0) bp_filt_lo = 0;
-	else
+	bp_filt_hi = (shift/2.0 + rtty_BW) / samplerate;
-		bpfilt = new fftfilt(0, rtty_BW / samplerate / 2.0, 1024);
 
-	if (bitfilt)
+	if (bpfilt)
-		bitfilt->setLength(symbollen / 8);//4);
+		bpfilt->create_filter(bp_filt_lo, bp_filt_hi);
 	else
-		bitfilt = new Cmovavg(symbollen / 8);//4);
+		bpfilt = new fftfilt(bp_filt_lo, bp_filt_hi, 1024);
+
+	bflen = symbollen/2;
+	if (bitfilt)
+		bitfilt->setLength(bflen);
+	else
+		bitfilt = new Cmovavg(bflen);
 
 // stop length = 1, 1.5 or 2 bits
 	rtty_stop = progdefaults.rtty_stop;
@@ -191,12 +196,12 @@ void rtty::restart()
 	pipeptr = 0;
 	poscnt = negcnt = 0;
 	posfreq = negfreq = 0.0;
-	
+
 	metric = 0.0;
 
-	snprintf(msg1, sizeof(msg1), "Shft %-4.0f", rtty_shift); 
+	snprintf(msg1, sizeof(msg1), "Shft %-4.0f", rtty_shift);
 	put_Status1(msg1);
-	snprintf(msg2, sizeof(msg2), "Baud %-4.1f", rtty_baud); 
+	snprintf(msg2, sizeof(msg2), "Baud %-4.1f", rtty_baud);
 	put_Status2(msg2);
 	put_MODEstatus(mode);
 	for (int i = 0; i < 1024; i++) QI[i].re = QI[i].im = 0.0;
@@ -205,7 +210,7 @@ void rtty::restart()
 	freqerrlo = freqerrhi = 0.0;
 	sigsearch = 0;
 	dspcnt = 2*(nbits + 2);//nbits + 2; //2 * symbollen * (nbits + 2);
-	
+
 	clear_zdata = true;
 }
 
@@ -216,18 +221,18 @@ rtty::rtty(trx_mode tty_mode)
 	mode = tty_mode;
 
 	samplerate = RTTY_SampleRate;
-	fragmentsize = 256;
+//	fragmentsize = 256; // not needed in any modem implementation for fldigi
-	
+
 	bpfilt = (fftfilt *)0;
-	
+
 	bitfilt = (Cmovavg *)0;
-	
+
 	hilbert = new C_FIR_filter();
 	hilbert->init_hilbert(37, 1);
 
 	pipe = new double[MAXPIPE];
 	dsppipe = new double [MAXPIPE];
-		
+
 	restart();
 }
 
@@ -255,9 +260,9 @@ complex rtty::mixer(complex in)
 	z = z * in;
 
 	phaseacc -= TWOPI * frequency / samplerate;
-	if (phaseacc > M_PI) 
+	if (phaseacc > M_PI)
 		phaseacc -= TWOPI;
-	else if (phaseacc < M_PI) 
+	else if (phaseacc < M_PI)
 		phaseacc += TWOPI;
 
 	return z;
@@ -381,7 +386,7 @@ int rtty::rx(bool bit)
 	case RTTY_RX_STATE_STOP:
 		if (--counter == 0) {
 			if (bit) {
-				if ((metric >= progStatus.sldrSquelchValue && progStatus.sqlonoff)|| !progStatus.sqlonoff) {				
+				if ((metric >= progStatus.sldrSquelchValue && progStatus.sqlonoff)|| !progStatus.sqlonoff) {
 					c = decode_char();
 					if ( c != 0 )
 						put_rx_char(c);
@@ -467,16 +472,19 @@ int rtty::rx_process(const double *buf, int len)
 
 	if (progdefaults.RTTY_BW != rtty_BW) {
 		rtty_BW = progdefaults.RTTY_BW;
-		bpfilt->create_filter(0, rtty_BW / samplerate / 2.0);
+		bp_filt_lo = (shift/2.0 - rtty_BW) / samplerate;
+		if (bp_filt_lo < 0) bp_filt_lo = 0;
+		bp_filt_hi = (shift/2.0 + rtty_BW) / samplerate;
+		bpfilt->create_filter(bp_filt_lo, bp_filt_hi);
 		wf->redraw_marker();
 	}
 
 	Metric();
 
 	while (len-- > 0) {
-		
+
 // create analytic signal from sound card input samples
-		
+
 		z.re = z.im = *buf++;
 		hilbert->run(z, z);
 
@@ -489,18 +497,18 @@ int rtty::rx_process(const double *buf, int len)
 		n = bpfilt->run(z, &zp);
 		if (n) {
 			for (int i = 0; i < n; i++) {
-			
+
 // measure phase difference between successive samples to determine
 // the frequency of the baseband signal (+rtty_baud or -rtty_baud)
 // see class complex definiton for operator %
-			
+
 				fin = (prevsmpl % zp[i]).arg() * samplerate / TWOPI;
 				prevsmpl = zp[i];
 
 // filter the result with a moving average filter
-			
+
 				f = bitfilt->run(fin);
-			
+
 // track the + and - frequency excursions separately to derive an afc signal
 
                 rotate = -4.0 * M_PI * freqerr / rtty_shift;
@@ -512,7 +520,7 @@ int rtty::rx_process(const double *buf, int len)
 					posfreq += fin;
 					QI[i].re = zp[i].re;
 					QI[i].im = xmix * zp[i].im;
-				} 
+				}
 				if (fin < 0.0) {
 					negcnt++;
 					negfreq += fin;
@@ -520,25 +528,28 @@ int rtty::rx_process(const double *buf, int len)
 					QI[i].im = zp[i].re;
 				}
 				QI[i] = QI[i] * complex(cos(rotate), sin(rotate));
-                avgsig = decayavg(avgsig, 1.25 * zp[i].mag(), 64);
+                avgsig = decayavg(avgsig, 1.25 * zp[i].mag(), 128);//64);
-				
+
-				if (avgsig > 0) 
+				if (avgsig > 0)
 				    QI[i] = QI[i] / avgsig;
 
 //	hysterisis dead zone in frequency discriminator bit detector
 
-				if (dspcnt && (--dspcnt % (nbits + 2) == 0)) {
-					pipe[pipeptr] = f / shift; // display filtered signal		
-					pipeptr = (pipeptr + 1) % symbollen;
-				}
-
 				if (f > deadzone )
 					bit = true;
 				if (f < -deadzone)
 					bit = false;
+
+				if (dspcnt && (--dspcnt % (nbits + 2) == 0)) {
+//					pipe[pipeptr] = bit ? .5 : -.5;
+					pipe[pipeptr] = f / shift;
+//					pipe[pipeptr] = fin / shift;//f / shift; // display filtered signal
+					pipeptr = (pipeptr + 1) % symbollen;
+				}
+
 //				if (!progdefaults.RTTY_USB)
 //					bit = !bit;
-	
+
 				rxflag = rx (reverse ? !bit : bit);
 
 				if (rxflag == 2) {
@@ -547,7 +558,7 @@ int rtty::rx_process(const double *buf, int len)
 					if (poscnt && negcnt) {
 						poserr = posfreq/poscnt;
 						negerr = negfreq/negcnt;
-						
+
 // compute the frequency error as the median of + and - relative freq's
 						if (sigsearch) sigsearch--;
 
@@ -618,7 +629,7 @@ double rtty::FSKnco()
 void rtty::send_symbol(int symbol)
 {
 	double freq;
-	
+
 	if (reverse)
 		symbol = !symbol;
 
@@ -626,7 +637,7 @@ void rtty::send_symbol(int symbol)
 		freq = get_txfreq_woffset() + shift / 2.0;
 	else
 		freq = get_txfreq_woffset() - shift / 2.0;
-    
+
 	for (int i = 0; i < symbollen; i++) {
 		outbuf[i] = nco(freq);
 		if (symbol)
@@ -645,7 +656,7 @@ void rtty::send_stop()
 {
 	double freq;
 	bool invert = reverse;
-	
+
 	if (invert)
 		freq = get_txfreq_woffset() - shift / 2.0;
 	else
@@ -693,7 +704,7 @@ void rtty::send_char(int c)
 			c = letters[c];
 		else
 			c = figures[c];
-		if (c) 
+		if (c)
 			put_echo_char(c);
 	}
 }
@@ -800,7 +811,7 @@ int rtty::tx_process()
 		return 0;
 
 // switch case if necessary
-	
+
 	if ((c & 0x300) != txmode) {// == 0) {
 		if (txmode == FIGURES) {
 			send_char(LETTERS);

src/dialogs/confdialog.cxx

@@ -3249,6 +3249,7 @@ an merging"));
                 cntCWdash2dot->type(1);
                 cntCWdash2dot->minimum(2.5);
                 cntCWdash2dot->maximum(4);
+                cntCWdash2dot->step(0.1);
                 cntCWdash2dot->value(3);
                 cntCWdash2dot->callback((Fl_Callback*)cb_cntCWdash2dot);
                 cntCWdash2dot->align(FL_ALIGN_RIGHT);
@@ -3259,6 +3260,7 @@ an merging"));
                 cntCWrisetime->type(1);
                 cntCWrisetime->minimum(0);
                 cntCWrisetime->maximum(15);
+                cntCWrisetime->step(0.1);
                 cntCWrisetime->value(4);
                 cntCWrisetime->callback((Fl_Callback*)cb_cntCWrisetime);
                 cntCWrisetime->align(FL_ALIGN_RIGHT);
@@ -3362,6 +3364,7 @@ an merging"));
                 valDominoEX_BW->type(1);
                 valDominoEX_BW->minimum(1);
                 valDominoEX_BW->maximum(2);
+                valDominoEX_BW->step(0.1);
                 valDominoEX_BW->value(1.5);
                 valDominoEX_BW->callback((Fl_Callback*)cb_valDominoEX_BW);
                 valDominoEX_BW->align(FL_ALIGN_RIGHT);
@@ -3376,6 +3379,7 @@ an merging"));
               { Fl_Value_Slider* o = valDomCWI = new Fl_Value_Slider(15, 207, 260, 20, _("CWI threshold"));
                 valDomCWI->tooltip(_("CWI detection and suppression"));
                 valDomCWI->type(1);
+                valDomCWI->step(0.01);
                 valDomCWI->textsize(14);
                 valDomCWI->callback((Fl_Callback*)cb_valDomCWI);
                 valDomCWI->align(FL_ALIGN_TOP);
@@ -3862,10 +3866,10 @@ an merging"));
               { Fl_Value_Slider* o = sldrRTTYbandwidth = new Fl_Value_Slider(100, 295, 300, 20, _("Receive filter bandwidth"));
                 sldrRTTYbandwidth->tooltip(_("Adjust the DSP bandwidth"));
                 sldrRTTYbandwidth->type(1);
-                sldrRTTYbandwidth->minimum(50);
+                sldrRTTYbandwidth->minimum(5);
-                sldrRTTYbandwidth->maximum(1200);
+                sldrRTTYbandwidth->maximum(200);
-                sldrRTTYbandwidth->step(5);
+                sldrRTTYbandwidth->step(1);
-                sldrRTTYbandwidth->value(400);
+                sldrRTTYbandwidth->value(25);
                 sldrRTTYbandwidth->textsize(14);
                 sldrRTTYbandwidth->callback((Fl_Callback*)cb_sldrRTTYbandwidth);
                 sldrRTTYbandwidth->align(FL_ALIGN_TOP_LEFT);
@@ -3906,6 +3910,7 @@ an merging"));
                 valTHOR_BW->type(1);
                 valTHOR_BW->minimum(1);
                 valTHOR_BW->maximum(2);
+                valTHOR_BW->step(0.1);
                 valTHOR_BW->value(1.5);
                 valTHOR_BW->callback((Fl_Callback*)cb_valTHOR_BW);
                 valTHOR_BW->align(FL_ALIGN_RIGHT);
@@ -3914,6 +3919,7 @@ an merging"));
               { Fl_Value_Slider* o = valThorCWI = new Fl_Value_Slider(15, 194, 260, 20, _("CWI threshold"));
                 valThorCWI->tooltip(_("CWI detection and suppression"));
                 valThorCWI->type(1);
+                valThorCWI->step(0.01);
                 valThorCWI->textsize(14);
                 valThorCWI->callback((Fl_Callback*)cb_valThorCWI);
                 valThorCWI->align(FL_ALIGN_TOP);
@@ -4503,6 +4509,7 @@ ll with your audio device."));
                 valPCMvolume->tooltip(_("Set the sound card PCM level"));
                 valPCMvolume->type(1);
                 valPCMvolume->selection_color((Fl_Color)FL_SELECTION_COLOR);
+                valPCMvolume->step(0.01);
                 valPCMvolume->value(0.8);
                 valPCMvolume->textsize(14);
                 valPCMvolume->callback((Fl_Callback*)cb_valPCMvolume);

src/dialogs/confdialog.fl

@@ -1605,7 +1605,7 @@ progdefaults.changed = true;}
               Fl_Value_Slider sldrRTTYbandwidth {
                 label {Receive filter bandwidth}
                 callback {progdefaults.RTTY_BW = o->value();}
-                tooltip {Adjust the DSP bandwidth} xywh {100 295 300 20} type Horizontal align 5 minimum 50 maximum 1200 step 5 value 400 textsize 14
+                tooltip {Adjust the DSP bandwidth} xywh {100 295 300 20} type Horizontal align 5 minimum 5 maximum 200 step 1 value 25 textsize 14
                 code0 {o->value(progdefaults.RTTY_BW);}
               }
             }

src/include/rtty.h

@@ -95,6 +95,10 @@ private:
 	Cmovavg *bitfilt;
 	fftfilt *bpfilt;
 
+	int bflen;
+	double bp_filt_lo;
+	double bp_filt_hi;
+
 	double *pipe;
 	double *dsppipe;
 	int pipeptr;

src/waterfall/waterfall.cxx

@@ -67,6 +67,7 @@
 #include "confdialog.h"
 #include "flmisc.h"
 #include "gettext.h"
+#include "rtty.h"
 
 using namespace std;
 
@@ -199,13 +200,46 @@ void WFdisp::initMarkers() {
 // draw a marker of specified width and colour centred at freq and clrM
 inline void WFdisp::makeMarker_(int width, const RGB* color, int freq, const RGB* clrMin, RGB* clrM, const RGB* clrMax)
 {
-	// clamp marker to image width
+	if (active_modem->get_mode() == MODE_RTTY) {
+	// rtty has two bandwidth indicators on the waterfall
+	// upper and lower frequency
+		int bw_limit_hi = (int)((_SHIFT[progdefaults.rtty_shift]/2 + progdefaults.RTTY_BW));
+		int bw_limit_lo = (int)((_SHIFT[progdefaults.rtty_shift]/2 - progdefaults.RTTY_BW));
+		int bw_freq = static_cast<int>(freq + 0.5);
+		int bw_lower1 = -bw_limit_hi;
+		int bw_upper1 = -bw_limit_lo;
+		int bw_lower2 = bw_limit_lo;
+		int bw_upper2 = bw_limit_hi;
+		if (bw_lower1 + bw_freq < 0) 
+			bw_lower1 -= bw_lower1 + bw_freq;
+		if (bw_upper1 + bw_freq < 0)
+			bw_lower2 -= bw_lower2 + bw_freq;
+		if (bw_upper2 + bw_freq > scale_width)
+			bw_upper2 -= bw_upper2 + bw_freq - scale_width;
+		if (bw_lower2 + bw_freq > scale_width)
+			bw_lower2 -= bw_lower2 + bw_freq - scale_width;
+	// draw it
+		RGB* clrPos;
+		for (int y = 0; y < WFMARKER - 2; y++) {
+			for (int x = bw_lower1; x < bw_upper1; x++) {
+				clrPos = clrM + x + y * scale_width;
+				if (clrPos > clrMin && clrPos < clrMax)
+					*clrPos = *color;
+			}
+			for (int x = bw_lower2; x < bw_upper2; x++) {
+				clrPos = clrM + x + y * scale_width;
+				if (clrPos > clrMin && clrPos < clrMax)
+					*clrPos = *color;
+			}
+		}
+		return;
+	}
+
 	int bw_lower = -width, bw_upper = width;
 	if (bw_lower + static_cast<int>(freq+0.5) < 0)
 		bw_lower -= bw_lower + static_cast<int>(freq+0.5);
 	if (bw_upper + static_cast<int>(freq+0.5) > scale_width)
 		bw_upper -= bw_upper + static_cast<int>(freq+0.5) - scale_width;
-
 	// draw it
 	RGB* clrPos;
 	for (int y = 0; y < WFMARKER - 2; y++) {
@@ -236,7 +270,7 @@ void WFdisp::makeMarker()
 	else if (mode >= MODE_FELDHELL && mode <= MODE_HELL80)
 		marker_width = (int)progdefaults.HELL_BW;
 	else if (mode == MODE_RTTY)
-		marker_width = (int)progdefaults.RTTY_BW;
+		marker_width = (int)_SHIFT[progdefaults.rtty_shift];
 	marker_width = (int)(marker_width / 2.0 + 1);
 
 	RGBmarker.R = progdefaults.bwTrackRGBI.R;
@@ -244,6 +278,7 @@ void WFdisp::makeMarker()
 	RGBmarker.B = progdefaults.bwTrackRGBI.B;
 
 	makeMarker_(marker_width, &RGBmarker, carrierfreq, clrMin, clrM, clrMax);
+
 	if (unlikely(active_modem->freqlocked())) {
 		int txfreq = active_modem->get_txfreq();
 		adjust_color_inv(RGBmarker.R, RGBmarker.G, RGBmarker.B, FL_BLACK, FL_RED);