restore aprs functionality

csdr/chain/__init__.py

@@ -1,5 +1,6 @@
 from csdr.module import Module
 from pycsdr.modules import Buffer
+from pycsdr.types import Format
 from typing import Union, Callable
 
 
@@ -133,7 +134,13 @@ class Chain(Module):
             self.clientReader.stop()
             self.clientReader = None
 
-    def getOutputFormat(self):
+    def getInputFormat(self) -> Format:
+        if self.workers:
+            return self.workers[0].getInputFormat()
+        else:
+            raise BufferError("getInputFormat on empty chain")
+
+    def getOutputFormat(self) -> Format:
         if self.workers:
             return self.workers[-1].getOutputFormat()
         else:

csdr/chain/analog.py

@@ -19,6 +19,7 @@ class Am(BaseDemodulatorChain):
 
 class NFm(BaseDemodulatorChain):
     def __init__(self, sampleRate: int):
+        self.sampleRate = sampleRate
         agc = Agc(Format.FLOAT)
         agc.setProfile(AgcProfile.SLOW)
         agc.setMaxGain(3)
@@ -30,6 +31,12 @@ class NFm(BaseDemodulatorChain):
         ]
         super().__init__(workers)
 
+    def setSampleRate(self, sampleRate: int) -> None:
+        if sampleRate == self.sampleRate:
+            return
+        self.sampleRate = sampleRate
+        self.replace(2, NfmDeemphasis(sampleRate))
+
 
 class WFm(BaseDemodulatorChain, FixedIfSampleRateChain, HdAudio):
     def __init__(self, sampleRate: int, tau: float):

csdr/chain/demodulator.py

@@ -6,9 +6,13 @@ class BaseDemodulatorChain(Chain):
     def supportsSquelch(self) -> bool:
         return True
 
+    def setSampleRate(self, sampleRate: int) -> None:
+        pass
+
 
 class SecondaryDemodulator(Chain):
-    pass
+    def supportsSquelch(self) -> bool:
+        return True
 
 
 class FixedAudioRateChain(ABC):

csdr/chain/digimodes.py

@@ -1,7 +1,10 @@
 from csdr.chain.demodulator import SecondaryDemodulator, FixedAudioRateChain, DialFrequencyReceiver
 from owrx.audio.chopper import AudioChopper
-from pycsdr.modules import Agc, Convert
+from owrx.aprs.kiss import KissDeframer
+from owrx.aprs import Ax25Parser, AprsParser
+from pycsdr.modules import Convert, FmDemod
 from pycsdr.types import Format
+from owrx.aprs.module import DirewolfModule
 
 
 class AudioChopperDemodulator(SecondaryDemodulator, FixedAudioRateChain, DialFrequencyReceiver):
@@ -16,3 +19,26 @@ class AudioChopperDemodulator(SecondaryDemodulator, FixedAudioRateChain, DialFre
 
     def setDialFrequency(self, frequency: int) -> None:
         self.chopper.setDialFrequency(frequency)
+
+
+class PacketDemodulator(SecondaryDemodulator, FixedAudioRateChain, DialFrequencyReceiver):
+    def __init__(self, service: bool = False):
+        self.parser = AprsParser()
+        workers = [
+            FmDemod(),
+            Convert(Format.FLOAT, Format.SHORT),
+            DirewolfModule(service=service),
+            KissDeframer(),
+            Ax25Parser(),
+            self.parser,
+        ]
+        super().__init__(workers)
+
+    def supportsSquelch(self) -> bool:
+        return False
+
+    def getFixedAudioRate(self) -> int:
+        return 48000
+
+    def setDialFrequency(self, frequency: int) -> None:
+        self.parser.setDialFrequency(frequency)

csdr/chain/selector.py

@@ -62,7 +62,7 @@ class Decimator(Chain):
 
 
 class Selector(Chain):
-    def __init__(self, inputRate: int, outputRate: int, shiftRate: float):
+    def __init__(self, inputRate: int, outputRate: int, shiftRate: float, withSquelch: bool = True):
         self.outputRate = outputRate
 
         self.shift = Shift(shiftRate)
@@ -73,12 +73,14 @@ class Selector(Chain):
         self.bandpassCutoffs = None
         self.setBandpass(-4000, 4000)
 
-        self.readings_per_second = 4
-        # s-meter readings are available every 1024 samples
-        # the reporting interval is measured in those 1024-sample blocks
-        self.squelch = Squelch(5, int(outputRate / (self.readings_per_second * 1024)))
+        workers = [self.shift, self.decimation, self.bandpass]
 
-        workers = [self.shift, self.decimation, self.bandpass, self.squelch]
+        if withSquelch:
+            self.readings_per_second = 4
+            # s-meter readings are available every 1024 samples
+            # the reporting interval is measured in those 1024-sample blocks
+            self.squelch = Squelch(5, int(outputRate / (self.readings_per_second * 1024)))
+            workers += [self.squelch]
 
         super().__init__(workers)