#39 WIP - finishes polyphase channel source processing of frequency

offset calculation and updating for channel frequency correction.

src/dsp/filter/channelizer/PolyphaseChannelManager.java

@@ -303,14 +303,17 @@ public class PolyphaseChannelManager implements Listener<SourceEvent>
         {
             List<Integer> indexes = mChannelCalculator.getChannelIndexes(channelSource.getTunerChannel());
 
+            long centerFrequency = mChannelCalculator.getCenterFrequencyForIndexes(indexes);
+
             //If the indexes size is the same then update the current processor, otherwise create a new one
             if(channelSource.getPolyphaseChannelOutputProcessor().getInputChannelCount() == indexes.size())
             {
                 channelSource.getPolyphaseChannelOutputProcessor().setPolyphaseChannelIndices(indexes);
+                channelSource.setFrequency(centerFrequency);
             }
             else
             {
-                channelSource.setPolyphaseChannelOutputProcessor(getOutputProcessor(indexes));
+                channelSource.setPolyphaseChannelOutputProcessor(getOutputProcessor(indexes), centerFrequency);
             }
         }
         catch(IllegalArgumentException iae)

src/dsp/filter/channelizer/PolyphaseChannelSource.java

@@ -36,6 +36,8 @@ public class PolyphaseChannelSource extends TunerChannelSource
     private ComplexToComplexBufferAssembler mComplexBufferAssembler = new ComplexToComplexBufferAssembler(2500);
     private IPolyphaseChannelOutputProcessor mPolyphaseChannelOutputProcessor;
     private double mChannelSampleRate;
+    private long mCenterFrequency;
+    private long mFrequencyCorrection;
 
     /**
      * Polyphase channelizer tuner channel source implementation.  Adapts the channel array output samples from the
@@ -84,8 +86,11 @@ public class PolyphaseChannelSource extends TunerChannelSource
 
     /**
      * Sets/updates the output processor for this channel source, replacing the existing output processor.
+     *
+     * @param outputProcessor to use
+     * @param frequency center for the channels processed by the output processor
      */
-    public void setPolyphaseChannelOutputProcessor(IPolyphaseChannelOutputProcessor outputProcessor)
+    public void setPolyphaseChannelOutputProcessor(IPolyphaseChannelOutputProcessor outputProcessor, long frequency)
     {
         //Lock on the channel output processor to block the channel results processor thread from servicing the
         //channel output processor's buffer while we change out the processors.
@@ -108,6 +113,13 @@ public class PolyphaseChannelSource extends TunerChannelSource
             {
                 existingProcessor.processChannelResults(mComplexBufferAssembler);
             }
+
+            //Finally, setup the frequency offset for the output processor and reset the frequency correction value
+            //to allow consumers to adjust and calculate a new frequency correction value, if needed.
+            mCenterFrequency = frequency;
+            mFrequencyCorrection = 0;
+            mPolyphaseChannelOutputProcessor.setFrequencyOffset(getFrequencyOffset());
+            broadcastConsumerSourceEvent(SourceEvent.frequencyCorrectionChange(mFrequencyCorrection));
         }
     }
 
@@ -153,14 +165,7 @@ public class PolyphaseChannelSource extends TunerChannelSource
     @Override
     public long getFrequencyCorrection()
     {
-        IPolyphaseChannelOutputProcessor processor = mPolyphaseChannelOutputProcessor;
-
-        if(processor != null)
-        {
-            return processor.getFrequencyCorrection();
-        }
-
-        return 0;
+        return mFrequencyCorrection;
     }
 
     /**
@@ -171,24 +176,20 @@ public class PolyphaseChannelSource extends TunerChannelSource
      */
     protected void setFrequencyCorrection(long value)
     {
-        if(mPolyphaseChannelOutputProcessor != null)
-        {
-            mPolyphaseChannelOutputProcessor.setFrequencyCorrection(value);
-            broadcastConsumerSourceEvent(SourceEvent.frequencyCorrectionChange(value));
-        }
+        mFrequencyCorrection = value;
+        updateFrequencyOffset();
+        broadcastConsumerSourceEvent(SourceEvent.frequencyCorrectionChange(mFrequencyCorrection));
     }
 
     /**
-     * Sets the center frequency for the incoming sample stream channel results
+     * Sets the center frequency for the incoming sample stream channel results and resets frequency correction to zero.
      * @param frequency in hertz
      */
     @Override
     protected void setFrequency(long frequency)
     {
-        if(mPolyphaseChannelOutputProcessor != null)
-        {
-            mPolyphaseChannelOutputProcessor.setFrequency(frequency);
-        }
+        mCenterFrequency = frequency;
+        setFrequencyCorrection(0);
     }
 
     @Override
@@ -200,4 +201,25 @@ public class PolyphaseChannelSource extends TunerChannelSource
             mPolyphaseChannelOutputProcessor.processChannelResults(mComplexBufferAssembler);
         }
     }
+
+    /**
+     * Calculates the frequency offset required to mix the incoming signal to the desired output baseband
+     */
+    private long getFrequencyOffset()
+    {
+        return getTunerChannel().getFrequency() - mCenterFrequency + mFrequencyCorrection;
+    }
+
+    /**
+     * Updates the frequency offset being applied by the output processor.  Calculates the offset using the center
+     * frequency of the incoming polyphase channel results and the desired output channel frequency adjusted by any
+     * requested frequency correction value.
+     */
+    private void updateFrequencyOffset()
+    {
+        synchronized(mPolyphaseChannelOutputProcessor)
+        {
+            mPolyphaseChannelOutputProcessor.setFrequencyOffset(getFrequencyOffset());
+        }
+    }
 }

src/dsp/filter/channelizer/output/ChannelOutputProcessor.java

@@ -60,16 +60,15 @@ public abstract class ChannelOutputProcessor implements IPolyphaseChannelOutputP
         mChannelResultsQueue = new OverflowableTransferQueue<>((int)(sampleRate * 3), (int)(sampleRate * 0.5));
     }
 
+    /**
+     * Sets the frequency offset to apply to the incoming samples to mix the desired signal to baseband.
+     * @param frequencyOffset in hertz
+     */
     @Override
-    public void setFrequency(long frequency)
+    public void setFrequencyOffset(long frequencyOffset)
     {
-
-    }
-
-    @Override
-    public long getFrequencyCorrection()
-    {
-        return 0;
+        mFrequencyCorrectionMixer.setFrequency(frequencyOffset);
+        mFrequencyCorrectionEnabled = (frequencyOffset != 0);
     }
 
     @Override
@@ -160,20 +159,6 @@ public abstract class ChannelOutputProcessor implements IPolyphaseChannelOutputP
             mFrequencyCorrectionMixer.quadrature());
     }
 
-    /**
-     * Specifies a frequency correction value to be applied to channel samples output from this polyphase channelizer
-     * output processor.
-     *
-     * @param frequencyCorrection offset value
-     */
-    @Override
-    public void setFrequencyCorrection(long frequencyCorrection)
-    {
-        mFrequencyCorrectionMixer.setFrequency(frequencyCorrection);
-
-        mFrequencyCorrectionEnabled = (frequencyCorrection != 0);
-    }
-
     /**
      * Indicates if this channel has a frequency correction offset
      */

src/dsp/filter/channelizer/output/IPolyphaseChannelOutputProcessor.java

@@ -40,23 +40,12 @@ public interface IPolyphaseChannelOutputProcessor
     void processChannelResults(ComplexSampleListener listener);
 
     /**
-     * Sets the center frequency of the incoming channel results samples
+     * Sets the desired frequency offset from center.  The samples will be mixed with an oscillator set to this offset
+     * frequency to produce an output where the desired signal is centered in the passband.
+     *
      * @param frequency in hertz
      */
-    void setFrequency(long frequency);
-
-    /**
-     * Specifies the frequency correction (+/-) that should be applied to samples extracted from the polyphase
-     * channelizer output results.
-     *
-     * @param frequencyCorrection correction value
-     */
-    void setFrequencyCorrection(long frequencyCorrection);
-
-    /**
-     * Current frequency correction value.
-     */
-    long getFrequencyCorrection();
+    void setFrequencyOffset(long frequency);
 
     /**
      * Indicates the number of input channels processed by this output processor