RTL - RMS based soft squelch and tweaks; #125

include/dsd.h

@@ -270,6 +270,7 @@ typedef struct
   int rtl_udp_port;
   int rtl_bandwidth;
   int rtl_started;
+  int rtl_rms;
   int monitor_input_audio;
   int pulse_raw_rate_in;
   int pulse_raw_rate_out;
@@ -1108,6 +1109,7 @@ void cleanup_rtlsdr_stream();
 void get_rtlsdr_sample(int16_t *sample, dsd_opts * opts, dsd_state * state);
 void rtlsdr_sighandler();
 void rtl_dev_tune(dsd_opts * opts, long int frequency);
+int rtl_return_rms();
 #endif
 //DMR TRELLIS
 void CDMRTrellisTribitsToBits(const unsigned char* tribits, unsigned char* payload);

src/dsd_frame_sync.c

@@ -448,6 +448,18 @@ getFrameSync (dsd_opts * opts, dsd_state * state)
               state->minref = state->min;
             }
 
+          //if using an rtl input method, do not look for sync patterns if the rms value is lower than our 'soft squelch' level
+          if (opts->audio_in_type == 3 && opts->rtl_rms < opts->rtl_squelch_level) //tests show floor level around 40, and signal breaking 100, default is 100 for level
+          {
+            if (opts->frame_nxdn48 == 1 || opts->frame_nxdn96 == 1 || opts->frame_dpmr == 1)
+            {
+              goto SYNC_TEST_END;
+              //should we update min/max here? yes or no?
+              state->max = ((state->max) + lmax) / 2;
+              state->min = ((state->min) + lmin) / 2;
+            }
+          }
+
           strncpy (synctest, (synctest_p - 23), 24);
           if (opts->frame_p25p1 == 1)
             {
@@ -1553,6 +1565,8 @@ getFrameSync (dsd_opts * opts, dsd_state * state)
           }
           #endif //End Provoice Conventional
 
+          SYNC_TEST_END: ; //do nothing
+
         } // t >= 10
 
       if (exitflag == 1)

src/dsd_main.c

@@ -169,10 +169,11 @@ noCarrier (dsd_opts * opts, dsd_state * state)
       state->edacs_tuned_lcn = -1;
 
       //only for EDACS/PV
-      if (opts->frame_provoice == 1 && opts->wav_out_file != NULL)
+      if (opts->p25_trunk == 1 && opts->frame_provoice == 1 && opts->wav_out_file != NULL)
       {
         closeWavOutFile(opts, state);
       }
+
       state->last_cc_sync_time = time(NULL);
       //test to switch back to 10/4 P1 QPSK for P25 FDMA CC
 
@@ -528,13 +529,14 @@ initOpts (dsd_opts * opts)
   //all RTL user options -- enabled AGC by default due to weak signal related issues
   opts->rtl_dev_index = 0;        //choose which device we want by index number
   opts->rtl_gain_value = 0;     //mid value, 0 - AGC - 0 to 49 acceptable values
-  opts->rtl_squelch_level = 0; //fully open by default, want to specify level for things like NXDN with false positives
+  opts->rtl_squelch_level = 100; //100 by default, but only affects NXDN and dPMR during framesync test, compared to RMS value
   opts->rtl_volume_multiplier = 1; //sample multiplier; This multiplies the sample value to produce a higher 'inlvl' 
   opts->rtl_udp_port = 0; //set UDP port for RTL remote -- 0 by default, will be making this optional for some external/legacy use cases (edacs-fm, etc)
-  opts->rtl_bandwidth = 12; //changed recommended default to 12, 24 for ProVoice
+  opts->rtl_bandwidth = 6; //default was 12, but changed to 6 due to newer handling of rtl_bandwidth
-  opts->rtlsdr_ppm_error = 0; //initialize ppm with 0 value; bug reported by N.
+  opts->rtlsdr_ppm_error = 0; //initialize ppm with 0 value;
   opts->rtlsdr_center_freq = 850000000; //set to an initial value (if user is using a channel map, then they won't need to specify anything other than -i rtl if desired)
   opts->rtl_started = 0;
+  opts->rtl_rms = 0; //root means square power level on rtl input signal
   //end RTL user options
   opts->pulse_raw_rate_in   = 48000;
   opts->pulse_raw_rate_out  = 48000; //
@@ -1063,9 +1065,9 @@ usage ()
   printf ("  NOTE: all arguments after rtl are optional now for trunking, but user configuration is recommended\n");
   printf ("  dev  <num>    RTL-SDR Device Index Number\n");
   printf ("  freq <num>    RTL-SDR Frequency (851800000 or 851.8M) \n");
-  printf ("  gain <num>    RTL-SDR Device Gain (0-49)(default = 28)(0 = Hardware AGC, not recommended)\n");
+  printf ("  gain <num>    RTL-SDR Device Gain (0-49)(default = 0; Hardware AGC recommended)\n");
   printf ("  ppm  <num>    RTL-SDR PPM Error (default = 0)\n");
-  printf ("  bw   <num>    RTL-SDR VFO Bandwidth kHz (default = 12)(6, 8, 12, 24)  \n");
+  printf ("  bw   <num>    RTL-SDR Bandwidth kHz (default = 6)(4, 6, 8, 12, 16, 24)  \n");
   printf ("  sq   <num>    RTL-SDR Squelch Level (Optional)\n");
   printf ("  udp  <num>    RTL-SDR UDP Remote Port (Optional -- External Use Only)\n");
   printf (" Example: dsd-fme-zdev -fs -i rtl -C cap_plus_channel.csv -T\n"); //put a good example here, probably trunking so user doesn't have to enter the 'optional' arguments
@@ -1149,7 +1151,7 @@ usage ()
   printf ("                 (NOTE: P25 Data Channels Not Enabled (no handling) \n");
   printf ("  -U <port>     Enable RIGCTL/TCP; Set TCP Port for RIGCTL. (4532 on SDR++)\n");
   printf ("  -B <Hertz>    Set RIGCTL Setmod Bandwidth in Hertz (0 - default - OFF)\n");
-  printf ("                 P25 - 7000-12000; P25 (QPSK) - 12000; NXDN48 - 4000; DMR - 7000; EDACS/PV - 12500;\n");
+  printf ("                 P25 - 7000-12000; P25 (QPSK) - 12000; NXDN48 - 7000; NXDN96: 9000; DMR - 7000; EDACS/PV - 12500;\n");
   printf ("                 May vary based on system stregnth, etc.\n");
   printf ("  -t <secs>     Set Trunking or Fast Scan VC/sync loss hangtime in seconds. (default = 1 second) (decimal values permitted) \n");
   printf ("\n");
@@ -1343,7 +1345,7 @@ main (int argc, char **argv)
   }
 
   #ifdef AERO_BUILD
-  fprintf (stderr, "Build Version:  v2.0.1-7 Win32 \n");
+  fprintf (stderr, "Build Version:  v2.0.1-8 Win32 \n");
   #else
   fprintf (stderr, "Build Version:  %s \n", GIT_TAG);
   #endif
@@ -2253,7 +2255,7 @@ main (int argc, char **argv)
           opts.rtl_bandwidth = bw;
         }
         else 
-          opts.rtl_bandwidth = 12; //safe default
+          opts.rtl_bandwidth = 6; //new safe default
       }
       else goto RTLEND; 
 

src/dsd_ncurses.c

@@ -2133,15 +2133,16 @@ ncursesPrinter (dsd_opts * opts, dsd_state * state)
   }
   if (opts->audio_in_type == 3)
   {
-    printw ("| RTL Dev: %d;", opts->rtl_dev_index);
+    printw ("| RTL: %d;", opts->rtl_dev_index);
     if (opts->rtl_gain_value == 0)
       printw (" Gain: AGC;");
     else
       printw (" Gain: %idB;", opts->rtl_gain_value);
     printw (" PPM: %i;", opts->rtlsdr_ppm_error);
     printw (" SQ: %i;", opts->rtl_squelch_level);
+    printw (" RMS: %03i;", opts->rtl_rms);
     printw (" BW: %i kHz;", opts->rtl_bandwidth);
-    printw (" FREQ: %i Hz;", opts->rtlsdr_center_freq); 
+    printw (" FREQ: %i;", opts->rtlsdr_center_freq); 
     if (opts->rtl_udp_port != 0) printw ("\n| External Tuning on UDP Port: %i", opts->rtl_udp_port);
     printw ("\n");
   }
@@ -3437,6 +3438,8 @@ ncursesPrinter (dsd_opts * opts, dsd_state * state)
     if (opts->p25_trunk == 1 && opts->audio_in_type == 3) rtl_dev_tune (opts, state->p25_cc_freq);
     #endif
 
+    state->last_cc_sync_time = time(NULL);
+
   }
 
   if (state->lasttgR != 0 && opts->frame_provoice != 1 && c == 50) //'2' key, lockout slot 2 tdma tgR from tuning/playback during session
@@ -3490,6 +3493,8 @@ ncursesPrinter (dsd_opts * opts, dsd_state * state)
     if (opts->p25_trunk == 1 && opts->audio_in_type == 3) rtl_dev_tune (opts, state->p25_cc_freq);
     #endif
 
+    state->last_cc_sync_time = time(NULL);
+
   }
 
   if (c == 48) //'0' key, toggle upsampled audio smoothing

src/dsd_symbol.c

@@ -137,6 +137,7 @@ getSymbol (dsd_opts * opts, dsd_state * state, int have_sync)
           state->pulse_raw_out_buffer = sample; //steal raw out buffer sample here?
           pa_simple_write(opts->pulse_raw_dev_out, (void*)&state->pulse_raw_out_buffer, 2, NULL);
         }
+        opts->rtl_rms = rtl_return_rms();
 
 #endif
       }

src/nxdn_element.c

@@ -155,6 +155,8 @@ void NXDN_Elements_Content_decode(dsd_opts * opts, dsd_state * state,
           rtl_dev_tune (opts, state->p25_cc_freq);
           #endif
         }
+
+        state->last_cc_sync_time = time(NULL); //allow tuners a second to catch up, particularly rtl input
       }
       
       break;
@@ -795,7 +797,7 @@ void NXDN_decode_srv_info(dsd_opts * opts, dsd_state * state, uint8_t * Message)
 
   //poll for current frequency, will always be the control channel
   //this PDU is constantly pumped out on the CC CAC Message
-  if (opts->p25_trunk == 1)
+  if (opts->p25_trunk == 1 && opts->p25_is_tuned == 0) //changed this so the rtl tuning lag doesn't set RTCH frequency after tuning but before landing
   {
     long int ccfreq = 0;
     //if using rigctl, we can poll for the current frequency
@@ -805,7 +807,7 @@ void NXDN_decode_srv_info(dsd_opts * opts, dsd_state * state, uint8_t * Message)
       if (ccfreq != 0) state->p25_cc_freq = ccfreq;
     }
     //if using rtl input, we can ask for the current frequency tuned
-    else if (opts->audio_in_type == 3)
+    else if (opts->audio_in_type == 3) //after changing to rtl_dev_tune, this may lag a bit due to delay in sample delivery?
     {
       ccfreq = (long int)opts->rtlsdr_center_freq;
       if (ccfreq != 0) state->p25_cc_freq = ccfreq;

src/rtl_sdr_fm.cpp

@@ -628,9 +628,9 @@ int verbose_set_frequency(rtlsdr_dev_t *dev, uint32_t frequency)
 	int r;
 	r = rtlsdr_set_center_freq(dev, frequency);
 	if (r < 0) {
-		fprintf (stderr, "WARNING: Failed to set center freq.\n");
+		fprintf (stderr, " WARNING: Failed to set center freq.\n");
 	} else {
-		fprintf (stderr, "Tuned to %u Hz.\n", frequency);
+		fprintf (stderr, " Tuned to %u Hz.\n", frequency);
 	}
 	return r;
 }
@@ -984,7 +984,7 @@ void open_rtlsdr_stream(dsd_opts *opts)
 	}
 
 	dongle.dev_index = opts->rtl_dev_index;
-	demod.squelch_level = opts->rtl_squelch_level;
+	// demod.squelch_level = opts->rtl_squelch_level; //no longer used here, used in framesync vc rms value under select conditions
 	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);
@@ -1087,10 +1087,20 @@ void get_rtlsdr_sample(int16_t *sample, dsd_opts * opts, dsd_state * state)
 	pthread_rwlock_unlock(&output.rw);
 }
 
+//function may lag since it isn't running as its own thread
 void rtl_dev_tune(dsd_opts * opts, long int frequency)
 {
 	int r;
 	dongle.freq = opts->rtlsdr_center_freq = frequency;
 	optimal_settings(dongle.freq, demod.rate_in);
 	r = verbose_set_frequency(dongle.dev, dongle.freq);
+	dongle.mute = BUFFER_DUMP; //test this here -- seems to help with sample lag sending stale samples
+}
+
+//return RMS value (root means square) power level -- used as soft squelch inside of framesync
+int rtl_return_rms()
+{
+	int sr = 0;
+	sr = rms(demod.lowpassed, demod.lp_len, 1);
+	return (sr);
 }