WIP - Adds FS/4 up and down converter classes.

src/main/java/io/github/dsheirer/source/tuner/manager/ChannelSourceManager.java

@@ -54,6 +54,8 @@ public abstract class ChannelSourceManager implements ISourceEventProcessor
      */
     public abstract TunerChannelSource getSource(TunerChannel tunerChannel);
 
+    public abstract TunerChannelSource getSpecialSource(int index);
+
     /**
      * Adds a listener to receive source events
      */

src/main/java/io/github/dsheirer/source/tuner/manager/TunerChannelSourceManager.java

@@ -49,6 +49,13 @@ public class TunerChannelSourceManager extends ChannelSourceManager
         mTunerController.addListener(mPolyphaseChannelManager);
     }
 
+    @Override
+    public TunerChannelSource getSpecialSource(int index)
+    {
+        //TODO: remove this debug method
+        return mPolyphaseChannelManager.getSpecialChannel(index);
+    }
+
     /**
      * Indicates if the channel min/max frequencies are within the tunable frequency range of the tuner controller
      *