A-Netz: Option to set gain of paging tones

5 files changed, 37 insertions, 28 deletions

diff --git a/src/anetz/anetz.c b/src/anetz/anetz.c
index 539edf7..77493f7 100644
--- a/src/anetz/anetz.c
+++ b/src/anetz/anetz.c
@@ -168,7 +168,7 @@ static void anetz_timeout(struct timer *timer);
 static void anetz_go_idle(anetz_t *anetz);
 
 /* Create transceiver instance and link to a list. */
-int anetz_create(int kanal, const char *audiodev, int samplerate, double rx_gain, int page_sequence, int pre_emphasis, int de_emphasis, const char *write_rx_wave, const char *write_tx_wave, const char *read_rx_wave, int loopback, double loss_volume)
+int anetz_create(int kanal, const char *audiodev, int samplerate, double rx_gain, double page_gain, int page_sequence, int pre_emphasis, int de_emphasis, const char *write_rx_wave, const char *write_tx_wave, const char *read_rx_wave, int loopback, double loss_volume)
 {
 	anetz_t *anetz;
 	int rc;
@@ -194,7 +194,7 @@ int anetz_create(int kanal, const char *audiodev, int samplerate, double rx_gain
 	}
 
 	/* init audio processing */
-	rc = dsp_init_sender(anetz, page_sequence);
+	rc = dsp_init_sender(anetz, page_gain, page_sequence);
 	if (rc < 0) {
 		PDEBUG(DANETZ, DEBUG_ERROR, "Failed to init signal processing!\n");
 		goto error;
diff --git a/src/anetz/anetz.h b/src/anetz/anetz.h
index ed5c4d5..a464db3 100644
--- a/src/anetz/anetz.h
+++ b/src/anetz/anetz.h
@@ -34,6 +34,7 @@ typedef struct anetz {
 	int			tone_count;		/* how long has that tone been detected */
 	double			tone_phaseshift256;	/* how much the phase of sine wave changes per sample */
 	double			tone_phase256;		/* current phase */
+	double			page_gain;		/* factor to raise the paging tones */
 	int			page_sequence;		/* if set, use paging tones in sequence rather than parallel */
 	double			paging_phaseshift256[4];/* how much the phase of sine wave changes per sample */
 	double			paging_phase256[4];	/* current phase */
@@ -45,7 +46,7 @@ typedef struct anetz {
 
 double anetz_kanal2freq(int kanal, int unterband);
 int anetz_init(void);
-int anetz_create(int kanal, const char *audiodev, int samplerate, double rx_gain, int page_sequence, int pre_emphasis, int de_emphasis, const char *write_rx_wave, const char *write_tx_wave, const char *read_rx_wave, int loopback, double loss_volume);
+int anetz_create(int kanal, const char *audiodev, int samplerate, double rx_gain, double page_gain, int page_sequence, int pre_emphasis, int de_emphasis, const char *write_rx_wave, const char *write_tx_wave, const char *read_rx_wave, int loopback, double loss_volume);
 void anetz_destroy(sender_t *sender);
 void anetz_loss_indication(anetz_t *anetz);
 void anetz_receive_tone(anetz_t *anetz, int bit);
diff --git a/src/anetz/dsp.c b/src/anetz/dsp.c
index e47f7f2..ee5bdd7 100644
--- a/src/anetz/dsp.c
+++ b/src/anetz/dsp.c
@@ -37,8 +37,6 @@
 /* signaling */
 #define BANDWIDTH	15000.0	/* maximum bandwidth */
 #define TX_PEAK_TONE	8192.0	/* peak amplitude for all tones */
-#warning FIXME: only with emphasis, use seperate option for volume, override by sdr
-#define TX_PEAK_PAGE	32766.0	/* peak amplitude paging tone */
 #define CHUNK_DURATION	0.010	/* 10 ms */
 
 // FIXME: how long until we detect a tone?
@@ -56,7 +54,6 @@ static double fsk_tones[2] = {
 
 /* table for fast sine generation */
 int dsp_sine_tone[256];
-int dsp_sine_page[256];
 
 /* global init for audio processing */
 void dsp_init(void)
@@ -68,22 +65,16 @@ void dsp_init(void)
 	for (i = 0; i < 256; i++) {
 		s = sin((double)i / 256.0 * 2.0 * PI);
 		dsp_sine_tone[i] = (int)(s * TX_PEAK_TONE);
-		s = cos((double)i / 256.0 * 2.0 * PI);
-		dsp_sine_page[i] = (int)(s * TX_PEAK_PAGE);
 	}
 
 	if (TX_PEAK_TONE > 32767.0) {
 		fprintf(stderr, "TX_PEAK_TONE definition too high, please fix!\n");
 		abort();
 	}
-	if (TX_PEAK_PAGE > 32767.0) {
-		fprintf(stderr, "TX_PEAK_PAGE definition too high, please fix!\n");
-		abort();
-	}
 }
 
 /* Init transceiver instance. */
-int dsp_init_sender(anetz_t *anetz, int page_sequence)
+int dsp_init_sender(anetz_t *anetz, double page_gain, int page_sequence)
 {
 	int16_t *spl;
 	double coeff;
@@ -96,6 +87,11 @@ int dsp_init_sender(anetz_t *anetz, int page_sequence)
 	anetz->sender.bandwidth = BANDWIDTH;
 	anetz->sender.sample_deviation = 11000.0 / (double)TX_PEAK_TONE;
 
+	anetz->page_gain = page_gain;
+	if (page_gain * TX_PEAK_TONE > 32767.0) {
+		page_gain = 32767.0 / TX_PEAK_TONE;
+		PDEBUG_CHAN(DDSP, DEBUG_NOTICE, "Highest possible gain of paging tones is %.1f dB.\n", log10(page_gain) * 20);
+	}
 	anetz->page_sequence = page_sequence;
 
 	audio_init_loss(&anetz->sender.loss, LOSS_INTERVAL, anetz->sender.loss_volume, LOSS_TIME);
@@ -245,12 +241,12 @@ void dsp_set_paging(anetz_t *anetz, double *freq)
 }
 
 /* Generate audio stream of 4 simultanious paging tones. Keep phase for next call of function.
- * Use TX_PEAK_PAGE for all tones, which gives peak of (TX_PEAK_PAGE / 4) for each individual tone. */
+ * Use TX_PEAK_TONE*page_gain for all tones, which gives peak of 1/4th for each individual tone. */
 static void fsk_paging_tone(anetz_t *anetz, int16_t *samples, int length)
 {
 	double phaseshift[4], phase[4];
 	int i;
-	int32_t sample;
+	double sample;
 
 	for (i = 0; i < 4; i++) {
 		phaseshift[i] = anetz->paging_phaseshift256[i];
@@ -258,11 +254,11 @@ static void fsk_paging_tone(anetz_t *anetz, int16_t *samples, int length)
 	}
 
 	for (i = 0; i < length; i++) {
-		sample	= (int32_t)dsp_sine_page[((uint8_t)phase[0]) & 0xff]
-			+ (int32_t)dsp_sine_page[((uint8_t)phase[1]) & 0xff]
-			+ (int32_t)dsp_sine_page[((uint8_t)phase[2]) & 0xff]
-			+ (int32_t)dsp_sine_page[((uint8_t)phase[3]) & 0xff];
-		*samples++ = sample >> 2;
+		sample	= (int32_t)dsp_sine_tone[((uint8_t)phase[0]) & 0xff]
+			+ (int32_t)dsp_sine_tone[((uint8_t)phase[1]) & 0xff]
+			+ (int32_t)dsp_sine_tone[((uint8_t)phase[2]) & 0xff]
+			+ (int32_t)dsp_sine_tone[((uint8_t)phase[3]) & 0xff];
+		*samples++ = sample / 4.0 * anetz->page_gain;
 		phase[0] += phaseshift[0];
 		phase[1] += phaseshift[1];
 		phase[2] += phaseshift[2];
@@ -281,7 +277,7 @@ static void fsk_paging_tone(anetz_t *anetz, int16_t *samples, int length)
 /* Generate audio stream of 4 sequenced paging tones. Keep phase for next call
  * of function.
  *
- * Use TX_PEAK_PAGE / 2 for each tone, that is twice as much peak per tone.
+ * Use TX_PEAK_PAGE for each tone, that is four times higher per tone.
  *
  * Click removal when changing tones that have individual phase:
  * When tone changes to next tone, a transition of 2ms is performed. The last
@@ -304,12 +300,12 @@ static void fsk_paging_tone_sequence(anetz_t *anetz, int16_t *samples, int lengt
 	while (length) {
 		/* use tone, but during transition of tones, keep phase 0 degrees (high level) until next tone reaches 0 degrees (high level) */
 		if (!transition)
-			*samples++ = dsp_sine_page[((uint8_t)phase[tone]) & 0xff] >> 1;
+			*samples++ = dsp_sine_tone[((uint8_t)phase[tone]) & 0xff] * anetz->page_gain;
 		else {
 			/* fade between old an new tone */
 			*samples++
-				= (double)dsp_sine_page[((uint8_t)phase[(tone - 1) & 3]) & 0xff] * (double)(transition - count) / (double)transition / 2.0
-				+ (double)dsp_sine_page[((uint8_t)phase[tone]) & 0xff] * (double)count / (double)transition / 2.0;
+				= (double)dsp_sine_tone[((uint8_t)phase[(tone - 1) & 3]) & 0xff] * (double)(transition - count) / (double)transition / 2.0 * anetz->page_gain
+				+ (double)dsp_sine_tone[((uint8_t)phase[tone]) & 0xff] * (double)count / (double)transition / 2.0 * anetz->page_gain;
 		}
 		phase[0] += phaseshift[0];
 		phase[1] += phaseshift[1];
diff --git a/src/anetz/dsp.h b/src/anetz/dsp.h
index 3f78028..aff93a9 100644
--- a/src/anetz/dsp.h
+++ b/src/anetz/dsp.h
@@ -1,6 +1,6 @@
 
 void dsp_init(void);
-int dsp_init_sender(anetz_t *anetz, int page_seqeuence);
+int dsp_init_sender(anetz_t *anetz, double page_gain, int page_seqeuence);
 void dsp_cleanup_sender(anetz_t *anetz);
 void dsp_set_paging(anetz_t *anetz, double *freq);
 void anetz_set_dsp_mode(anetz_t *anetz, enum dsp_mode mode, int detect_reset);
diff --git a/src/anetz/main.c b/src/anetz/main.c
index d13d5be..a6fcfcb 100644
--- a/src/anetz/main.c
+++ b/src/anetz/main.c
@@ -22,6 +22,7 @@
 #include <getopt.h>
 #include <stdlib.h>
 #include <string.h>
+#include <math.h>
 #include "../common/main.h"
 #include "../common/debug.h"
 #include "../common/timer.h"
@@ -35,17 +36,21 @@
 #include "image.h"
 
 /* settings */
+double page_gain = 1;
 int page_sequence = 0;
 double lossdetect = 0;
 
 void print_help(const char *arg0)
 {
-	print_help_common(arg0, "");
+	print_help_common(arg0, "[-V 12] ");
 	/*      -                                                                             - */
 	printf(" -G --geo <lat>,<lon>\n");
 	printf("        Give your coordinates of your location, to find closest base station.\n");
 	printf("	(e.g. '--geo 51.186959,7.080194') Or use '--geo list' to get a list of\n");
 	printf("        all base station locations.\n");
+	printf(" -V --page-gain <dB>\n");
+	printf("        Raise the gain of paging tones to compensate loss due to pre-emphasis\n");
+	printf("        of the transmitter. (If you can't disable it.)\n");
 	printf(" -P --page-sequence 0 | <ms>\n");
 	printf("        Cycle paging tones, rather than sending simultaniously. Try 100.\n");
 	printf("        (default = '%d')\n", page_sequence);
@@ -61,15 +66,17 @@ static int handle_options(int argc, char **argv)
 {
 	int skip_args = 0;
 	char *p;
+	double gain_db;
 
 	static struct option long_options_special[] = {
 		{"geo", 1, 0, 'G'},
+		{"page-gain", 1, 0, 'V'},
 		{"page-sequence", 1, 0, 'P'},
 		{"loss", 1, 0, 'L'},
 		{0, 0, 0, 0}
 	};
 
-	set_options_common("G:P:L:", long_options_special);
+	set_options_common("G:V:P:L:", long_options_special);
 
 	while (1) {
 		int option_index = 0, c;
@@ -92,6 +99,11 @@ static int handle_options(int argc, char **argv)
 			fprintf(stderr, "Invalid geo parameter\n");
 			exit(0);
 			break;
+		case 'V':
+			gain_db = atof(optarg);
+			page_gain = pow(10, gain_db / 20.0);
+			skip_args += 2;
+			break;
 		case 'P':
 			page_sequence = atoi(optarg);
 			skip_args += 2;
@@ -171,7 +183,7 @@ int main(int argc, char *argv[])
 
 	/* create transceiver instance */
 	for (i = 0; i < num_kanal; i++) {
-		rc = anetz_create(kanal[i], audiodev[i], samplerate, rx_gain, page_sequence, do_pre_emphasis, do_de_emphasis, write_rx_wave, write_tx_wave, read_rx_wave, loopback, lossdetect / 100.0);
+		rc = anetz_create(kanal[i], audiodev[i], samplerate, rx_gain, page_gain, page_sequence, do_pre_emphasis, do_de_emphasis, write_rx_wave, write_tx_wave, read_rx_wave, loopback, lossdetect / 100.0);
 		if (rc < 0) {
 			fprintf(stderr, "Failed to create \"Sender\" instance. Quitting!\n");
 			goto fail;