initial work on freedv / codec2 support, refs #126

csdr/csdr.py

@@ -301,6 +301,15 @@ class dsp(object):
             chain += ["csdr amdemod_cf", "csdr fastdcblock_ff"]
             chain += last_decimation_block
             chain += ["csdr agc_ff", "csdr limit_ff", "csdr convert_f_s16"]
+        elif which == "freedv":
+            chain += ["csdr realpart_cf"]
+            chain += last_decimation_block
+            chain += [
+                "csdr agc_ff",
+                "csdr convert_f_s16",
+                "freedv_rx 1600 - -",
+                "sox -t raw -r 8000 -e signed-integer -b 16 -c 1 --buffer 32 - -t raw -r {output_rate} -e signed-integer -b 16 -c 1 - ",
+            ]
         elif which == "ssb":
             chain += ["csdr realpart_cf"]
             chain += last_decimation_block
@@ -571,6 +580,8 @@ class dsp(object):
             return 48000
         elif self.isWsjtMode() or self.isJs8():
             return 12000
+        elif self.get_demodulator() == "freedv":
+            return 8000
         return self.get_output_rate()
 
     def isDigitalVoice(self, demodulator=None):
@@ -664,7 +675,7 @@ 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() or self.isPocsag() else self.squelch_level
+        actual_squelch = -150 if self.isDigitalVoice() or self.isPacket() or self.isPocsag() or self.get_demodulator() == "freedv" else self.squelch_level
         if self.running:
             self.pipes["squelch_pipe"].write("%g\n" % (self.convertToLinear(actual_squelch)))
 

owrx/feature.py

@@ -39,6 +39,7 @@ class FeatureDetector(object):
         # optional features and their requirements
         "digital_voice_digiham": ["digiham", "sox"],
         "digital_voice_dsd": ["dsd", "sox", "digiham"],
+        "digital_voice_freedv": ["freedv_rx", "sox"],
         "wsjt-x": ["wsjtx", "sox"],
         "packet": ["direwolf", "sox"],
         "pocsag": ["digiham", "sox"],
@@ -401,3 +402,6 @@ class FeatureDetector(object):
         You can find instructions and downloads [here](https://o28.sischa.net/fifisdr/trac/wiki/De%3Arockprog).
         """
         return self.command_is_runnable("rockprog")
+
+    def has_freedv_rx(self):
+        return self.command_is_runnable("freedv_rx")

owrx/modes.py

@@ -48,6 +48,7 @@ class Modes(object):
         AnalogMode("dstar", "DStar", bandpass=Bandpass(-3250, 3250), requirements=["digital_voice_dsd"], squelch=False),
         AnalogMode("nxdn", "NXDN", bandpass=Bandpass(-3250, 3250), requirements=["digital_voice_dsd"], squelch=False),
         AnalogMode("ysf", "YSF", bandpass=Bandpass(-4000, 4000), requirements=["digital_voice_digiham"], squelch=False),
+        AnalogMode("freedv", "FDV", bandpass=Bandpass(300, 3000), requirements=["digital_voice_freedv"], squelch=False),
         DigitalMode("bpsk31", "BPSK31", underlying=["usb"]),
         DigitalMode("bpsk63", "BPSK63", underlying=["usb"]),
         DigitalMode("ft8", "FT8", underlying=["usb"], requirements=["wsjt-x"], service=True),