add ssb chain

csdr/__init__.py

@@ -38,6 +38,7 @@ from csdr.pipe import Pipe
 from csdr.chain.demodulator import DemodulatorChain
 from csdr.chain.fm import Fm
 from csdr.chain.am import Am
+from csdr.chain.ssb import Ssb
 
 import logging
 
@@ -126,6 +127,9 @@ class Dsp(DirewolfConfigSubscriber):
             elif which == "am":
                 self.pycsdr_chain = DemodulatorChain(self.samp_rate, self.get_audio_rate(), 0.0, Am())
                 return self.pycsdr_chain
+            elif which == "ssb":
+                self.pycsdr_chain = DemodulatorChain(self.samp_rate, self.get_audio_rate(), 0.0, Ssb())
+                return self.pycsdr_chain
 
         chain = ["nc -v 127.0.0.1 {nc_port}"]
         chain += ["csdr shift_addfast_cc --fifo {shift_pipe}"]

csdr/chain/ssb.py

@@ -0,0 +1,19 @@
+from csdr.chain import Chain
+from csdr.chain.demodulator import Demodulator
+from pycsdr.modules import RealPart, Agc, Convert
+from pycsdr.types import Format
+
+
+class Ssb(Demodulator):
+    def __init__(self):
+        workers = [
+            RealPart(),
+            # empty chain as placeholder for the "last decimation"
+            Chain(),
+            Agc(Format.FLOAT),
+            Convert(Format.FLOAT, Format.SHORT),
+        ]
+        super().__init__(*workers)
+
+    def setLastDecimation(self, decimation: Chain):
+        self.replace(1, decimation)