preliminary work to allow dynamic audio format switching

csdr/chain/dablin.py

@@ -1,4 +1,4 @@
-from csdr.chain.demodulator import BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain, HdAudio, \
+from csdr.chain.demodulator import BaseDemodulatorChain, FixedIfSampleRateChain, DynamicAudioRateChain, HdAudio, \
     MetaProvider, DabServiceSelector, DialFrequencyReceiver
 from csdr.module import PickleModule
 from csdreti.modules import EtiDecoder
@@ -58,8 +58,10 @@ class MetaProcessor(PickleModule):
         self.shifter.setRate(0)
 
 
-class Dablin(BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain, HdAudio, MetaProvider, DabServiceSelector, DialFrequencyReceiver):
+class Dablin(BaseDemodulatorChain, FixedIfSampleRateChain, DynamicAudioRateChain, HdAudio, MetaProvider, DabServiceSelector, DialFrequencyReceiver):
     def __init__(self):
+        self.audioRate = 48000
+
         shift = Shift(0)
         self.decoder = EtiDecoder()
 
@@ -77,7 +79,7 @@ class Dablin(BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain,
             shift,
             self.decoder,
             self.dablin,
-            Downmix(Format.FLOAT),
+            Downmix(Format.SHORT),
         ]
         super().__init__(workers)
 
@@ -90,8 +92,8 @@ class Dablin(BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain,
     def getFixedIfSampleRate(self) -> int:
         return 2048000
 
-    def getFixedAudioRate(self) -> int:
-        return 48000
+    def getAudioRate(self) -> int:
+        return self.audioRate
 
     def stop(self):
         self.processor.stop()

csdr/chain/demodulator.py

@@ -2,6 +2,10 @@ from csdr.chain import Chain
 from abc import ABC, ABCMeta, abstractmethod
 from pycsdr.modules import Writer
 
+import logging
+
+logger = logging.getLogger(__name__)
+
 
 class FixedAudioRateChain(ABC):
     @abstractmethod
@@ -9,6 +13,39 @@ class FixedAudioRateChain(ABC):
         pass
 
 
+class DynamicAudioRateListener(ABC):
+    @abstractmethod
+    def onAudioRateChange(self, rate: int):
+        pass
+
+
+class DynamicAudioRateChain(ABC):
+    def __init__(self):
+        self.listeners = []
+        super().__init__()
+
+    def addListener(self, listener: DynamicAudioRateListener):
+        if listener in self.listeners:
+            return
+        self.listeners.append(listener)
+
+    def removeListener(self, listener: DynamicAudioRateListener):
+        if listener not in self.listeners:
+            return
+        self.listeners.remove(listener)
+
+    def fireAudioRateChange(self, rate: int):
+        for listener in self.listeners:
+            try:
+                listener.onAudioRateChange(rate)
+            except:
+                logger.exception("error while sending audio rate change")
+
+    @abstractmethod
+    def getAudioRate(self) -> int:
+        pass
+
+
 class FixedIfSampleRateChain(ABC):
     @abstractmethod
     def getFixedIfSampleRate(self) -> int:

owrx/dab/dablin.py

@@ -7,7 +7,7 @@ class DablinModule(ExecModule):
         self.serviceId = 0
         super().__init__(
             Format.CHAR,
-            Format.FLOAT,
+            Format.SHORT,
             self._buildArgs()
         )
 

owrx/dsp.py

@@ -5,7 +5,7 @@ from owrx.modes import Modes, DigitalMode
 from csdr.chain import Chain
 from csdr.chain.demodulator import BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain, HdAudio, \
     SecondaryDemodulator, DialFrequencyReceiver, MetaProvider, SlotFilterChain, SecondarySelectorChain, \
-    DeemphasisTauChain, DemodulatorError, RdsChain, DabServiceSelector
+    DeemphasisTauChain, DemodulatorError, RdsChain, DabServiceSelector, DynamicAudioRateChain, DynamicAudioRateListener
 from csdr.chain.selector import Selector, SecondarySelector
 from csdr.chain.clientaudio import ClientAudioChain
 from csdr.chain.fft import FftChain
@@ -35,7 +35,7 @@ class ClientDemodulatorSecondaryDspEventClient(ABC):
         pass
 
 
-class ClientDemodulatorChain(Chain):
+class ClientDemodulatorChain(Chain, DynamicAudioRateListener):
     def __init__(self, demod: BaseDemodulatorChain, sampleRate: int, outputRate: int, hdOutputRate: int, audioCompression: str, secondaryDspEventReceiver: ClientDemodulatorSecondaryDspEventClient):
         self.sampleRate = sampleRate
         self.outputRate = outputRate
@@ -101,11 +101,16 @@ class ClientDemodulatorChain(Chain):
 
         if self.demodulator is not None:
             self.demodulator.stop()
+            if isinstance(self.demodulator, DynamicAudioRateChain):
+                self.demodulator.removeListener(self)
 
         self.demodulator = demodulator
 
         self.selector.setOutputRate(self._getSelectorOutputRate())
 
+        if isinstance(self.demodulator, DynamicAudioRateChain):
+            self.demodulator.addListener(self)
+
         clientRate = self._getClientAudioInputRate()
         self.demodulator.setSampleRate(clientRate)
 
@@ -155,6 +160,8 @@ class ClientDemodulatorChain(Chain):
     def _getClientAudioInputRate(self):
         if isinstance(self.demodulator, FixedAudioRateChain):
             return self.demodulator.getFixedAudioRate()
+        elif isinstance(self.demodulator, DynamicAudioRateChain):
+            return self.demodulator.getAudioRate()
         elif isinstance(self.secondaryDemodulator, FixedAudioRateChain):
             return self.secondaryDemodulator.getFixedAudioRate()
         else:
@@ -395,6 +402,9 @@ class ClientDemodulatorChain(Chain):
         if isinstance(self.demodulator, RdsChain):
             self.demodulator.setRdsRbds(self.rdsRbds)
 
+    def onAudioRateChange(self, rate: int):
+        self.clientAudioChain.setInputRate(self._getClientAudioInputRate())
+
 
 class ModulationValidator(OrValidator):
     """