Memory/CPU performance improvement and Audio/Mixer source restructuring

Converted to use float primitives and to keep samples in buffer format until the sample rate is decimated to 48kHz.  
Added new non-recursive, CIC decimation filter -- untested

Updated sound card/mixer input source management.  Now testing for mono/stereo support for each card and limiting channel choices accordingly.  Separated the mixersource into a ComplexMixer and and SimplexMixerSource.  The ComplexMixer is used for sound card based tuners like the funcube.  The SimplexMixerSource is used for demodulated sound card inputs.

Interfaces for sample handling - standardized on using 'Complex' to indicate I/Q samples and 'Simplex' to indicate demodulated float samples.  The processing chain now accepts either a decimated (48k) list of complex samples from a tuner channel source, or a 48k simplex buffer (array of demodulated float samples).

Resolved issue with HackRF tuner not applying tuner configuration information.

src/sample/complex/ComplexBuffer.java

@@ -0,0 +1,42 @@
+package sample.complex;
+
+import java.util.Arrays;
+
+public class ComplexBuffer
+{
+	private float[] mSamples;
+
+	/**
+	 * Wrapper around float array containing interleaved I/Q samples
+	 */
+	public ComplexBuffer( float[] samples )
+	{
+		mSamples = samples;
+	}
+
+	/**
+	 * Creates a deep copy of the buffer 
+	 */
+	public ComplexBuffer copyOf()
+	{
+		float[] copy = Arrays.copyOf( mSamples, mSamples.length );
+		
+		return new ComplexBuffer( copy );
+	}
+
+	/**
+	 * Interleaved I/Q float sample array
+	 */
+	public float[] getSamples()
+	{
+		return mSamples;
+	}
+
+	/**
+	 * Cleanup method to nullify all data and references
+	 */
+	public void dispose()
+	{
+		mSamples = null;
+	}
+}

src/sample/complex/ComplexSampleBroadcaster.java

@@ -0,0 +1,76 @@
+/*******************************************************************************
+ *     SDR Trunk 
+ *     Copyright (C) 2014 Dennis Sheirer
+ * 
+ *     This program is free software: you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License as published by
+ *     the Free Software Foundation, either version 3 of the License, or
+ *     (at your option) any later version.
+ * 
+ *     This program is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ * 
+ *     You should have received a copy of the GNU General Public License
+ *     along with this program.  If not, see <http://www.gnu.org/licenses/>
+ ******************************************************************************/
+package sample.complex;
+
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * Broadcasts received float samples to multiple listeners
+ */
+public class ComplexSampleBroadcaster implements ComplexSampleListener
+{
+	private CopyOnWriteArrayList<ComplexSampleListener> mListeners = 
+			new CopyOnWriteArrayList<ComplexSampleListener>();
+
+	@Override
+    public void receive( float i, float q )
+    {
+		broadcast( i, q );
+    }
+	
+	/**
+	 * Clear listeners to prepare for garbage collection
+	 */
+	public void dispose()
+	{
+		mListeners.clear();
+	}
+	
+	public boolean hasListeners()
+	{
+		return !mListeners.isEmpty();
+	}
+	
+	public int getListenerCount()
+	{
+		return mListeners.size();
+	}
+	
+	public void addListener( ComplexSampleListener listener )
+	{
+		mListeners.add( listener );
+	}
+	
+	public void removeListener( ComplexSampleListener listener )
+	{
+		mListeners.remove( listener );
+	}
+	
+	public void clear()
+	{
+		mListeners.clear();
+	}
+
+    public void broadcast( float i, float q )
+    {
+    	for( ComplexSampleListener listener: mListeners )
+    	{
+    		listener.receive( i, q );
+    	}
+    }
+}

src/sample/complex/ComplexSampleListener.java

@@ -0,0 +1,6 @@
+package sample.complex;
+
+public interface ComplexSampleListener
+{
+	public void receive( float i, float q );
+}

src/sample/complex/RTLComplexSample.java

@@ -1,57 +0,0 @@
-/*******************************************************************************
- *     SDR Trunk 
- *     Copyright (C) 2014 Dennis Sheirer
- * 
- *     This program is free software: you can redistribute it and/or modify
- *     it under the terms of the GNU General Public License as published by
- *     the Free Software Foundation, either version 3 of the License, or
- *     (at your option) any later version.
- * 
- *     This program is distributed in the hope that it will be useful,
- *     but WITHOUT ANY WARRANTY; without even the implied warranty of
- *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *     GNU General Public License for more details.
- * 
- *     You should have received a copy of the GNU General Public License
- *     along with this program.  If not, see <http://www.gnu.org/licenses/>
- ******************************************************************************/
-package sample.complex;
-
-@Deprecated
-public class RTLComplexSample extends ComplexSample
-{
-    private static final long serialVersionUID = 1L;
-
-	private static float[] mValues;
-
-	/**
-	 * Creates a lookup table that converts the 8-bit valued range from 0 - 255
-	 * into scaled float values of -128 to 0 to 127
-	 */
-	static
-	{
-		mValues = new float[ 256 ];
-		
-		float scale = (float)( 1.0f / 127.0f );
-		
-		for( int x = 0; x < 256; x++ )
-		{
-			mValues[ x ] = (float)( x - 128 ) * scale;
-		}
-		
-		mValues[ 128 ] = 0.0000001f;
-	}
-
-	/**
-	 * Constructs a complex sample from the sample format produced by the 
-	 * RTL-2832 chip, where the byte values run from 0 - 255, but represent
-	 * the value -127 to 127
-	 * 
-	 * @param left
-	 * @param right
-	 */
-	public RTLComplexSample( byte left, byte right )
-    {
-	    super( mValues[ left & 0xFF ], mValues[ right & 0xFF ] );
-    }
-}