Add RTL VFO bandwidth options

Add RTL VFO bandwidth options
-Y 8 for 8 kHz VFO
-Y 24 for 24 kHz VFO

Should work at any interval where 48 cleanly divides by a number

include/dsd.h

@@ -142,6 +142,7 @@ typedef struct
   int rtl_squelch_level;
   int rtl_volume_multiplier;
   int rtl_udp_port;
+  int rtl_bandwidth;
   int monitor_input_audio;
 } dsd_opts;
 

src/dsd_main.c

@@ -185,6 +185,7 @@ initOpts (dsd_opts * opts)
   opts->rtl_squelch_level = 0; //fully open by default, want to specify level for things like NXDN with false positives
   opts->rtl_volume_multiplier = 1; //set multipler from rtl sample to 'boost volume'
   opts->rtl_udp_port = 6020; //set UDP port for RTL remote
+  opts->rtl_bandwidth = 48; //48000 default value
 }
 
 void
@@ -327,7 +328,8 @@ usage ()
   printf ("  -D <num>      RTL-SDR Device Index Number\n");
   printf ("  -G <num>      RTL-SDR Device Gain (0-49) (default = 0 Auto Gain)\n");
   printf ("  -L <num>      RTL-SDR Squelch Level (0 - Open, 25 - Little, 50 - Higher)(Just have to guess really...)\n");
-  printf ("  -V <num>      RTL-SDR Sample Gain Multiplier (default = 1)(2-3 recommended, still testing) \n");
+  printf ("  -V <num>      RTL-SDR Sample Gain Multiplier (default = 1)(1-3 recommended, still testing) \n");
+  printf ("  -Y <num>      RTL-SDR VFO Bandwidth kHz (default = 48)(6, 8, 12, 16, 24, 48) \n");
   printf ("  -U <num>      RTL-SDR UDP Remote Port (default = 6020)\n");
   printf ("\n");
   printf ("Scanner control options:\n");
@@ -574,7 +576,7 @@ main (int argc, char **argv)
   exitflag = 0;
   signal (SIGINT, sigfun);
 
-  while ((c = getopt (argc, argv, "haep:P:qstv:z:i:o:d:c:g:nw:B:C:R:f:m:u:x:A:S:M:G:D:L:V:U:Wrl")) != -1)
+  while ((c = getopt (argc, argv, "haep:P:qstv:z:i:o:d:c:g:nw:B:C:R:f:m:u:x:A:S:M:G:D:L:V:U:Y:Wrl")) != -1)
     {
       opterr = 0;
       switch (c)
@@ -656,6 +658,10 @@ main (int argc, char **argv)
           sscanf (optarg, "%d", &opts.rtl_dev_index);
           break;
 
+        case 'Y': //Set rtl VFO bandwidth --recommend 6, 12, 24, 36, 48, default 48? or 12?
+          sscanf (optarg, "%d", &opts.rtl_bandwidth);
+          break;
+
         case 'W': //monitor_input_audio if no sync
           opts.monitor_input_audio = 1;
           printf ("Monitor Source Audio if no sync detected (WIP!)\n");
@@ -689,7 +695,7 @@ main (int argc, char **argv)
           break;
         case 'c':
           opts.rtlsdr_center_freq = (uint32_t)atofs(optarg);
-          printf("Tuning to frequency: %i\n", opts.rtlsdr_center_freq);
+          printf("Tuning to frequency: %i Hz\n", opts.rtlsdr_center_freq);
           break;
         case 'g':
           sscanf (optarg, "%f", &opts.audio_gain);

src/rtl_sdr_fm.cpp

@@ -31,7 +31,7 @@
 #include <rtl-sdr.h>
 #include "dsd.h"
 
-#define DEFAULT_SAMPLE_RATE		48000 //48000
+//#define DEFAULT_SAMPLE_RATE		48000 //moved to opts->rtl_bandwidth
 #define DEFAULT_BUF_LENGTH		(1 * 16384)
 #define MAXIMUM_OVERSAMPLE		16 //16
 #define MAXIMUM_BUF_LENGTH		(MAXIMUM_OVERSAMPLE * DEFAULT_BUF_LENGTH)
@@ -51,6 +51,10 @@ static int atan_lut_coef = 8;
 #include <arpa/inet.h>
 static pthread_t socket_freq;
 
+int rtl_bandwidth;
+int bandwidth_multiplier;
+int bandwidth_divisor = 48000; //divide bandwidth by this to get multiplier for the for j loop to queue.push
+
 short int volume_multiplier;
 short int port;
 //
@@ -582,7 +586,8 @@ static void *demod_thread_fn(void *arg)
 		pthread_rwlock_wrlock(&o->rw);
 		for (int i = 0; i < d->result_len; i++)
 		{
-			o->queue.push(d->result[i]);
+			for (int j=0; j < bandwidth_multiplier; j++){
+				o->queue.push(d->result[i]);}
 		}
 		pthread_rwlock_unlock(&o->rw);
 		safe_cond_signal(&o->ready, &o->ready_m);
@@ -802,7 +807,8 @@ static void *controller_thread_fn(void *arg)
 
 void dongle_init(struct dongle_state *s)
 {
-	s->rate = DEFAULT_SAMPLE_RATE;
+	//s->rate = DEFAULT_SAMPLE_RATE;
+	s->rate = rtl_bandwidth;
 	s->gain = AUTO_GAIN; // tenths of a dB
 	s->mute = 0;
 	s->direct_sampling = 0;
@@ -813,8 +819,10 @@ void dongle_init(struct dongle_state *s)
 
 void demod_init(struct demod_state *s)
 {
-	s->rate_in = DEFAULT_SAMPLE_RATE;
+	//s->rate_in = DEFAULT_SAMPLE_RATE;
-	s->rate_out = DEFAULT_SAMPLE_RATE;
+	//s->rate_out = DEFAULT_SAMPLE_RATE;
+	s->rate_in = rtl_bandwidth;
+	s->rate_out = rtl_bandwidth;
 	s->squelch_level = 0;
 	s->conseq_squelch = 10;
 	s->terminate_on_squelch = 0;
@@ -848,7 +856,8 @@ void demod_cleanup(struct demod_state *s)
 
 void output_init(struct output_state *s)
 {
-	s->rate = DEFAULT_SAMPLE_RATE;
+	//s->rate = DEFAULT_SAMPLE_RATE;
+	s->rate = rtl_bandwidth;
 	pthread_rwlock_init(&s->rw, NULL);
 	pthread_cond_init(&s->ready, NULL);
 	pthread_mutex_init(&s->ready_m, NULL);
@@ -1043,7 +1052,10 @@ void open_rtlsdr_stream(dsd_opts *opts)
 {
   struct sigaction sigact;
   int r;
-
+	rtl_bandwidth =  opts->rtl_bandwidth * 1000; //multiple by 1000 to get rate
+	//rtl_bandwidth = 48000;
+	bandwidth_multiplier = (bandwidth_divisor / rtl_bandwidth); //find multiple with no remainder if oddball number entered
+	//bandwidth_multiplier = 1;
   dongle_init(&dongle);
   demod_init(&demod);
   output_init(&output);
@@ -1060,7 +1072,13 @@ void open_rtlsdr_stream(dsd_opts *opts)
 
 	if (opts->audio_in_type == 3) {
 		dongle.dev_index = opts->rtl_dev_index;
+		//rtl_bandwidth =  opts->rtl_bandwidth * 1000; //multiple by 1000 to get rate
+		//rtl_bandwidth = 48000;
+		//bandwidth_multiplier = rtl_bandwidth / bandwidth_divisor; //find multiple with no remainder if oddball number entered
+		//bandwidth_multiplier = 1;
 		demod.squelch_level = opts->rtl_squelch_level;  //adding user definable squelch level to prevent false positives on account of noise in NXDN etc
+		fprintf(stderr, "Setting RTL VFO Bandwidth to %d Hz\n", rtl_bandwidth);
+		fprintf(stderr, "Setting RTL Sample Multiplier to %d\n", bandwidth_multiplier);
 		fprintf(stderr, "Setting RTL Squelch Level to %d\n", demod.squelch_level);
 		port = opts->rtl_udp_port;
 	}