SDR: Display spectrum graph together with channel numbers and position

src/common/display.h

@@ -49,7 +49,7 @@ void display_iq_on(int on);
 void display_iq_limit_scroll(int on);
 void display_iq(float *samples, int length);
 
-void display_spectrum_init(int samplerate);
+void display_spectrum_init(int samplerate, double center_frequency);
 void display_spectrum_on(int on);
 void display_spectrum_limit_scroll(int on);
 void display_spectrum(float *samples, int length);

src/common/display_spectrum.c

@@ -33,10 +33,11 @@ static char screen[HEIGHT][MAX_DISPLAY_WIDTH];
 static uint8_t screen_color[HEIGHT][MAX_DISPLAY_WIDTH];
 static int spectrum_on = 0;
 static double db = 100;
+static double center_frequency, frequency_range;
 
 static dispspectrum_t disp;
 
-void display_spectrum_init(int samplerate)
+void display_spectrum_init(int samplerate, double _center_frequency)
 {
 	memset(&disp, 0, sizeof(disp));
 	disp.interval_max = (double)samplerate * DISPLAY_INTERVAL + 0.5;
@@ -44,6 +45,9 @@ void display_spectrum_init(int samplerate)
 	if (disp.interval_max < MAX_DISPLAY_SPECTRUM - 1)
 		disp.interval_max = MAX_DISPLAY_SPECTRUM - 1;
 	memset(buffer_max, 0, sizeof(buffer_max));
+
+	center_frequency = _center_frequency;
+	frequency_range = (double)samplerate;
 }
 
 void display_spectrum_on(int on)
@@ -90,6 +94,8 @@ void display_spectrum_limit_scroll(int on)
  */
 void display_spectrum(float *samples, int length)
 {
+	sender_t *sender;
+	char print_channel[32], print_frequency[32];
 	int width, h;
 	int pos, max;
 	double *buffer_I, *buffer_Q;
@@ -213,6 +219,34 @@ void display_spectrum(float *samples, int length)
 					}
 				}
 			}
+			for (sender = sender_head; sender; sender = sender->next) {
+				j = (int)((sender->empfangsfrequenz - center_frequency) / frequency_range * (double) fft_size + width / 2 + 0.5);
+				if (j < 0 || j >= width) /* check out-of-range, should not happen */
+					continue;
+				for (k = 0; k < HEIGHT; k++) {
+					/* skip yellow graph */
+					if (screen_color[k][j] == 13)
+						continue;
+					screen[k][j] = ':';
+					screen_color[k][j] = 12;
+				}
+				sprintf(print_channel, "Ch%d", sender->kanal);
+				for (o = 0; o < (int)strlen(print_channel); o++) {
+					s = j - strlen(print_channel) + o;
+					if (s >= 0 && s < width) {
+						screen[HEIGHT - 1][s] = print_channel[o];
+						screen_color[HEIGHT - 1][s] = 7;
+					}
+				}
+				sprintf(print_frequency, "%.4f", sender->empfangsfrequenz / 1e6);
+				for (o = 0; o < (int)strlen(print_frequency); o++) {
+					s = j + o + 1;
+					if (s >= 0 && s < width) {
+						screen[HEIGHT - 1][s] = print_frequency[o];
+						screen_color[HEIGHT - 1][s] = 7;
+					}
+				}
+			}
 			printf("\0337\033[H");
 			for (j = 0; j < HEIGHT; j++) {
 				for (k = 0; k < width; k++) {

src/common/sdr.c

@@ -114,9 +114,6 @@ void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_freq
 		threads = 1;
 	}
 
-	display_iq_init(samplerate);
-	display_spectrum_init(samplerate);
-
 	bandwidth = 2.0 * (max_deviation + max_modulation);
 	PDEBUG(DSDR, DEBUG_INFO, "Require bandwidth of 2 * (%.1f + %.1f) = %.1f\n", max_deviation / 1000, max_modulation / 1000, bandwidth / 1000);
 
@@ -340,6 +337,9 @@ void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_freq
 		tx_center_frequency = temp;
 	}
 
+	display_iq_init(samplerate);
+	display_spectrum_init(samplerate, rx_center_frequency);
+
 #ifdef HAVE_UHD
 	if (sdr_config->uhd) {
 		rc = uhd_open(sdr_config->channel, sdr_config->device_args, sdr_config->stream_args, sdr_config->tune_args, sdr_config->tx_antenna, sdr_config->rx_antenna, tx_center_frequency, rx_center_frequency, sdr_config->samplerate, sdr_config->tx_gain, sdr_config->rx_gain, sdr_config->bandwidth, sdr_config->uhd_tx_timestamps);

src/tv/main.c

@@ -41,6 +41,7 @@ enum paging_signal;
 #include "tv_modulate.h"
 #include "channels.h"
 
+void *sender_head = NULL;
 int use_sdr = 0;
 int num_kanal = 1; /* only one channel used for debugging */