pass through programme information

csdr/chain/dablin.py

@@ -1,8 +1,8 @@
-from csdr.chain.demodulator import BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain, HdAudio
+from csdr.chain.demodulator import BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain, HdAudio, MetaProvider
 from csdr.module import PickleModule
 from csdreti.modules import EtiDecoder
 from owrx.dab.dablin import DablinModule
-from pycsdr.modules import Downmix, Buffer, Shift
+from pycsdr.modules import Downmix, Buffer, Shift, Writer
 from pycsdr.types import Format
 from typing import Optional
 from random import random
@@ -21,6 +21,7 @@ class MetaProcessor(PickleModule):
         super().__init__()
 
     def process(self, data):
+        result = {}
         if "coarse_frequency_shift" in data:
             value = int(data["coarse_frequency_shift"])
             if value > 0:
@@ -36,9 +37,13 @@ class MetaProcessor(PickleModule):
                 logger.debug("ffs: %f", value)
                 logger.debug("fine adjustment - new shift: %f", self.shift)
                 self.shifter.setRate(self.shift)
+        if "programmes" in data:
+            result["programmes"] = data["programmes"]
+        # don't send out data if there was nothing interesting for the client
+        return result if result else None
 
 
-class Dablin(BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain, HdAudio):
+class Dablin(BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain, HdAudio, MetaProvider):
     def __init__(self):
         shift = Shift(0)
         decoder = EtiDecoder()
@@ -47,6 +52,8 @@ class Dablin(BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain,
         decoder.setMetaWriter(metaBuffer)
         self.processor = MetaProcessor(shift)
         self.processor.setReader(metaBuffer.getReader())
+        # use a dummy to start with. it won't run without.
+        # will be replaced by setMetaWriter().
         self.processor.setWriter(Buffer(Format.CHAR))
 
         workers = [
@@ -71,3 +78,6 @@ class Dablin(BaseDemodulatorChain, FixedIfSampleRateChain, FixedAudioRateChain,
 
     def stop(self):
         self.processor.stop()
+
+    def setMetaWriter(self, writer: Writer) -> None:
+        self.processor.setWriter(writer)

csdr/module/__init__.py

@@ -86,6 +86,9 @@ class ThreadModule(AutoStartModule, Thread, metaclass=ABCMeta):
         self.reader.stop()
 
     def start(self):
+        # don't start twice.
+        if self.is_alive():
+            return
         Thread.start(self)