IQ recording file playback partial checkin.

NOTE: only the gui components and settings handling have been implemented.  Actual recording playback is not yet implemented.

Partial checkin of initial P25 decoder development.  

NOTE: P25 decoder is not yet functional.

src/dsp/fsk/C4FMDecoder.java

@@ -0,0 +1,66 @@
+package dsp.fsk;
+
+import instrument.Instrumentable;
+import instrument.tap.Tap;
+import instrument.tap.stream.FloatTap;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import sample.Listener;
+
+public class C4FMDecoder implements Listener<Float>, Instrumentable
+{
+	private final String TAP_C4FM_INPUT = "C4FM Input";
+	private ArrayList<Tap> mTaps;
+	private FloatTap mInputTap;
+	
+	public C4FMDecoder()
+	{
+	}
+
+	@Override
+    public List<Tap> getTaps()
+    {
+		if( mTaps == null )
+		{
+			mTaps = new ArrayList<Tap>();
+
+			FloatTap floatTap = new FloatTap( TAP_C4FM_INPUT, 0, 1.0f );
+			mTaps.add( floatTap );
+		}
+		
+	    return mTaps;
+    }
+
+	@Override
+    public void addTap( Tap tap )
+    {
+		switch( tap.getName() )
+		{
+			case TAP_C4FM_INPUT:
+				mInputTap = (FloatTap)tap; 
+				break;
+		}
+    }
+
+	@Override
+    public void removeTap( Tap tap )
+    {
+		switch( tap.getName() )
+		{
+			case TAP_C4FM_INPUT:
+				mInputTap = null; 
+				break;
+		}
+    }
+
+	@Override
+    public void receive( Float t )
+    {
+		if( mInputTap != null )
+		{
+			mInputTap.receive( t );
+		}
+    }
+}