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/adapter/ChannelShortAdapter.java

@@ -0,0 +1,85 @@
+/*******************************************************************************
+ *     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.adapter;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+import source.mixer.MixerChannel;
+
+/**
+ * Converts 16-bit little endian byte data into an array of floats 
+ */
+public class ChannelShortAdapter extends SampleAdapter
+{
+	private ByteOrder mByteOrder = ByteOrder.LITTLE_ENDIAN;
+	private MixerChannel mMixerChannel;
+	
+	public ChannelShortAdapter( MixerChannel channel )
+	{
+		/* Only use with LEFT/RIGHT channels */
+		assert( channel != MixerChannel.MONO );
+		
+		mMixerChannel = channel;
+	}
+			
+	@Override
+    public float[] convert( byte[] samples )
+    {
+		float[] processed = new float[ samples.length / 4 ];
+
+		int pointer = 0;
+
+		/* Wrap byte array in a byte buffer so we can process them as shorts */
+		ByteBuffer buffer = ByteBuffer.wrap( samples );
+
+		/* Set endian to correct byte ordering */
+		buffer.order( mByteOrder );
+
+        while( buffer.hasRemaining() )
+        {
+        	if( mMixerChannel == MixerChannel.LEFT )
+        	{
+            	processed[ pointer ] = (float)buffer.getShort();
+
+            	/* Throw away the right channel */
+            	buffer.getShort();
+        	}
+        	else
+        	{
+            	/* Throw away the left channel */
+            	buffer.getShort();
+
+            	processed[ pointer ] = (float)buffer.getShort();
+        	}
+        	
+        	pointer++;
+        }
+        
+        return processed;
+    }
+
+	/**
+	 * Set byte interpretation to little or big endian.  Defaults to LITTLE
+	 * endian
+	 */
+	public void setByteOrder( ByteOrder order )
+	{
+		mByteOrder = order;
+	}
+}