add scaffolding for pocsag decoding

bands.json

@@ -160,7 +160,10 @@
   {
     "name": "70cm",
     "lower_bound": 430000000,
-    "upper_bound": 440000000
+    "upper_bound": 440000000,
+    "frequencies": {
+      "pocsag": 439987500
+    }
   },
   {
     "name": "23cm",

bookmarks.json

@@ -129,11 +129,6 @@
     "frequency": 439937500,
     "modulation": "dmr"
   },
-  {
-    "name": "Pocsag",
-    "frequency": 439987500,
-    "modulation": "nfm"
-  },
   {
     "name": "DB0ULR",
     "frequency": 145575000,

csdr/csdr.py

@@ -244,6 +244,11 @@ class dsp(object):
             if self.last_decimation != 1.0:
                 chain += ["csdr fractional_decimator_ff {last_decimation}"]
             return chain + ["csdr convert_f_s16", "direwolf -c {direwolf_config} -r {audio_rate} -t 0 -q d -q h - 1>&2"]
+        elif which == "pocsag":
+            chain += ["csdr fmdemod_quadri_cf"]
+            if self.last_decimation != 1.0:
+                chain += ["csdr fractional_decimator_ff {last_decimation}"]
+            return chain + ["fsk_demodulator", "pocsag_decoder"]
 
     def set_secondary_demodulator(self, what):
         if self.get_secondary_demodulator() == what:
@@ -448,6 +453,8 @@ class dsp(object):
             return 48000
         elif self.isWsjtMode():
             return 12000
+        elif self.isPocsag():
+            return 12000
         return self.get_output_rate()
 
     def isDigitalVoice(self, demodulator=None):
@@ -465,6 +472,11 @@ class dsp(object):
             demodulator = self.get_secondary_demodulator()
         return demodulator == "packet"
 
+    def isPocsag(self, demodulator=None):
+        if demodulator is None:
+            demodulator = self.get_secondary_demodulator()
+        return demodulator == "pocsag"
+
     def set_output_rate(self, output_rate):
         if self.output_rate == output_rate:
             return
@@ -528,7 +540,7 @@ class dsp(object):
     def set_squelch_level(self, squelch_level):
         self.squelch_level = squelch_level
         # no squelch required on digital voice modes
-        actual_squelch = -150 if self.isDigitalVoice() or self.isPacket() else self.squelch_level
+        actual_squelch = -150 if self.isDigitalVoice() or self.isPacket() or self.isPocsag() else self.squelch_level
         if self.running:
             self.modification_lock.acquire()
             self.squelch_pipe_file.write("%g\n" % (self.convertToLinear(actual_squelch)))

htdocs/index.html

@@ -187,6 +187,7 @@
                         <option value="jt9" data-feature="wsjt-x">JT9</option>
                         <option value="ft4" data-feature="wsjt-x">FT4</option>
                         <option value="packet" data-feature="packet">Packet</option>
+                        <option value="pocsag" data-feature="pocsag">Pocsag</option>
                     </select>
                 </div>
                 <div class="openwebrx-panel-line">

htdocs/openwebrx.js

@@ -2160,6 +2160,7 @@ function demodulator_digital_replace(subtype) {
             demodulators[0].set();
             break;
         case "packet":
+        case "pocsag":
             secondary_demod_start(subtype);
             demodulator_analog_replace('nfm', true);
             break;

owrx/feature.py

@@ -32,6 +32,7 @@ class FeatureDetector(object):
         "digital_voice_dsd": ["dsd", "sox", "digiham"],
         "wsjt-x": ["wsjtx", "sox"],
         "packet": ["direwolf", "sox"],
+        "pocsag": ["digiham", "sox"],
     }
 
     def feature_availability(self):
@@ -181,6 +182,8 @@ class FeatureDetector(object):
                     "mbe_synthesizer",
                     "gfsk_demodulator",
                     "digitalvoice_filter",
+                    "fsk_demodulator",
+                    "pocsag_decoder",
                 ],
             ),
             True,