Merge pull request #338 from DSheirer/330-p25-c4fm-decoder-update

330 p25 c4fm decoder update

build.gradle

@@ -54,6 +54,8 @@ dependencies {
     compile 'org.apache.axis:axis-jaxrpc:1.4'
     compile 'org.apache.axis:axis:1.4'
     compile 'com.fasterxml.jackson.dataformat:jackson-dataformat-xml:2.9.3'
+    compile 'org.kordamp.ikonli:ikonli-javafx:2.1.1'
+    compile 'org.kordamp.ikonli:ikonli-fontawesome-pack:2.1.1'
 }
 
 task wrapper(type: Wrapper) {

src/main/java/io/github/dsheirer/buffer/ComplexCircularBuffer.java

@@ -1,6 +1,6 @@
 /*******************************************************************************
  *     SDR Trunk 
- *     Copyright (C) 2014 Dennis Sheirer
+ *     Copyright (C) 2014-2018 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
@@ -30,61 +30,78 @@ import java.util.Arrays;
  */
 public class ComplexCircularBuffer
 {
-	Complex[] mBuffer;
+    Complex[] mBuffer;
-	int mBufferPointer = 0;
+    int mBufferPointer = 0;
 
-	public ComplexCircularBuffer( int size )
+    public ComplexCircularBuffer(int size)
-	{
+    {
-		mBuffer = new Complex[ size ];
+        mBuffer = new Complex[size];
 
-		Arrays.fill( mBuffer, new Complex( 1.0f, 1.0f ) );
+        Arrays.fill(mBuffer, new Complex(1.0f, 1.0f));
-	}
+    }
 
-	/**
+    public int length()
-	 * Returns the sample currently pointed to in the buffer and stores the
+    {
-	 * new sample in its place
+        return mBuffer.length;
-	 * @param sample
+    }
-	 * @return
-	 */
-	public Complex get( Complex sample )
-	{
-		Complex retVal = mBuffer[ mBufferPointer ];
 
-		put( sample );
+    /**
+     * Returns the sample currently pointed to in the buffer and stores the
+     * new sample in its place
+     *
+     * @param sample
+     * @return
+     */
+    public Complex get(Complex sample)
+    {
+        Complex retVal = mBuffer[mBufferPointer];
 
-		return retVal;
+        put(sample);
-	}
 
-	public void put( Complex sample )
+        return retVal;
-	{
+    }
-		mBuffer[ mBufferPointer ] = sample;
 
-		mBufferPointer++;
+    public void put(Complex sample)
+    {
+        mBuffer[mBufferPointer] = sample;
 
-		if( mBufferPointer >= mBuffer.length )
+        mBufferPointer++;
-		{
-			mBufferPointer = 0;
-		}
-	}
 
-	public Complex[] get( int count )
+        if(mBufferPointer >= mBuffer.length)
-	{
+        {
-		Complex[] samples = new Complex[ count ];
+            mBufferPointer = 0;
+        }
+    }
 
-		int tempCounter = mBufferPointer;
+    /**
+     * Returns the (count) oldest samples in a time ordered array
+     */
+    public Complex[] get(int count)
+    {
+        Complex[] samples = new Complex[count];
 
-		for( int x = 0; x < count; x++ )
+        int tempCounter = mBufferPointer;
-		{
-			samples[ x ] = mBuffer[ tempCounter ];
 
-			tempCounter++;
+        for(int x = 0; x < count; x++)
+        {
+            samples[x] = mBuffer[tempCounter];
 
-			if( tempCounter > mBuffer.length - 1 )
+            tempCounter++;
-			{
-				tempCounter = 0;
-			}
-		}
 
-		return samples;
+            if(tempCounter > mBuffer.length - 1)
-	}
+            {
+                tempCounter = 0;
+            }
+        }
+
+        return samples;
+    }
+
+    /**
+     * Returns the samples in a time-ordered array
+     */
+    public Complex[] getAll()
+    {
+        return get(length());
+    }
 }

src/main/java/io/github/dsheirer/buffer/DoubleCircularBuffer.java

@@ -17,64 +17,164 @@
  ******************************************************************************/
 package io.github.dsheirer.buffer;
 
+import org.apache.commons.math3.stat.descriptive.moment.Mean;
+import org.apache.commons.math3.stat.descriptive.moment.StandardDeviation;
+import org.apache.commons.math3.stat.descriptive.moment.Variance;
+import org.apache.commons.math3.stat.descriptive.rank.Max;
+import org.apache.commons.math3.stat.descriptive.rank.Min;
+
 import java.util.Arrays;
 
 /**
- * Circular sample buffer - allocates a buffer and stores samples in a circular
+ * Circular sample buffer - allocates a buffer and stores samples in a circular fashion, overwriting older samples with
- * fashion, overwriting older samples with newly arrived samples.  Initially
+ * newly arrived samples.  Initially fills buffer with 0-valued (default) samples or with a specified value.
- * fills buffer with 0-valued samples
- * 
- * Can be used as a delay-type buffer, to delay samples by the 'size' amount
  */
 public class DoubleCircularBuffer
 {
-	double[] mBuffer;
+    private StandardDeviation mStandardDeviation;
-	int mBufferPointer = 0;
+    private Variance mVariance;
+    private Max mMax;
+    private Mean mMean;
+    private Min mMin;
+    private double[] mBuffer;
+    private int mBufferPointer = 0;
 
-	public DoubleCircularBuffer( int size )
+    /**
-	{
+     * Creates a circular double buffer of the specified size and all entries filled with the specified initial value.
-		mBuffer = new double[ size ];
+     * @param size of the buffer
+     * @param initialFillValue to fill the buffer entries
+     */
+    public DoubleCircularBuffer(int size, double initialFillValue)
+    {
+        mBuffer = new double[size];
+        Arrays.fill(mBuffer, initialFillValue);
+    }
 
-		Arrays.fill( mBuffer, 0.0 );
+    /**
-	}
+     * Creates a circular double buffer of the specified size and all entries filled with an initial value of zero.
+     * @param size of the buffer
+     */
+    public DoubleCircularBuffer(int size)
+    {
+        this(size, 0.0);
+    }
 
-	/**
+    /**
-	 * Puts the new value into the buffer and returns the oldest buffer value
+     * Puts the new value into the buffer and returns the oldest buffer value that it replaced
-	 * that it replaced
+     *
-	 * @param newValue
+     * @param newValue to add to the buffer
-	 * @return
+     * @return oldest value that was overwritten by the new value
-	 */
+     */
-	public double get( double newValue )
+    public double get(double newValue)
-	{
+    {
-		double oldestSample = mBuffer[ mBufferPointer ];
+        double oldestSample = mBuffer[mBufferPointer];
 
-		mBuffer[ mBufferPointer ] = newValue;
+        mBuffer[mBufferPointer] = newValue;
 
-		mBufferPointer++;
+        mBufferPointer++;
 
-		if( mBufferPointer >= mBuffer.length )
+        if(mBufferPointer >= mBuffer.length)
-		{
+        {
-			mBufferPointer = 0;
+            mBufferPointer = 0;
-		}
+        }
 
-		return oldestSample;
+        return oldestSample;
-	}
+    }
 
-	/**
+    public double[] getAll()
-	 * Returns the maximum from the values currently in the buffer
+    {
-	 */
+        int valuePointer = 0;
-	public double max()
+        double[] values = new double[mBuffer.length];
-	{
+        int bufferPointer = mBufferPointer;
-		double max = 0.0d;
 
-		for( int x = 0; x < mBuffer.length; x++ )
+        while(valuePointer < values.length)
-		{
+        {
-			if( mBuffer[ x ] > max )
+            values[valuePointer++] = mBuffer[bufferPointer++];
-			{
-				max = mBuffer[ x ];
-			}
-		}
 
-		return max;
+            if(bufferPointer >= mBuffer.length)
-	}
+            {
+                bufferPointer = 0;
+            }
+        }
+
+        return values;
+    }
+
+    /**
+     * Places the new value into the buffer, overwriting the oldest value
+     * @param newValue to add to the buffer
+     */
+    public void put(double newValue)
+    {
+        mBuffer[mBufferPointer] = newValue;
+
+        mBufferPointer++;
+
+        if(mBufferPointer >= mBuffer.length)
+        {
+            mBufferPointer = 0;
+        }
+    }
+
+    /**
+     * Returns the maximum from the values currently in the buffer
+     */
+    public double max()
+    {
+        if(mMax == null)
+        {
+            mMax = new Max();
+        }
+
+        return mMax.evaluate(mBuffer, 0, mBuffer.length);
+    }
+
+    /**
+     * Returns the minimum from the values currently in the buffer
+     */
+    public double min()
+    {
+        if(mMin == null)
+        {
+            mMin = new Min();
+        }
+
+        return mMin.evaluate(mBuffer, 0, mBuffer.length);
+    }
+
+    public double standardDeviation()
+    {
+        if(mStandardDeviation == null)
+        {
+            mStandardDeviation = new StandardDeviation();
+        }
+
+        return mStandardDeviation.evaluate(mBuffer);
+    }
+
+    /**
+     * Calculates the variance of the values contained in this buffer
+     */
+    public double variance()
+    {
+        if(mVariance == null)
+        {
+            mVariance = new Variance();
+        }
+
+        return mVariance.evaluate(mBuffer);
+    }
+
+    /**
+     * Calculates the average/mean of the values contained in this buffer
+     */
+    public double mean()
+    {
+        if(mMean == null)
+        {
+            mMean = new Mean();
+        }
+
+        return mMean.evaluate(mBuffer, 0, mBuffer.length);
+    }
 }

src/main/java/io/github/dsheirer/buffer/FloatCircularBuffer.java

@@ -25,94 +25,96 @@ import java.util.Arrays;
  * fills buffer with 0-valued samples
  *
  * Can be used as a delay-type buffer, to delay samples by the 'size' amount
- * @author denny
  *
+ * @author denny
  */
 public class FloatCircularBuffer
 {
-	float[] mBuffer;
+    float[] mBuffer;
-	int mBufferPointer = 0;
+    int mBufferPointer = 0;
 
-	public FloatCircularBuffer( int size )
+    /**
-	{
+     * Creates a circular double buffer of the specified size and all entries filled with the specified initial value.
-		mBuffer = new float[ size ];
+     *
+     * @param size of the buffer
+     * @param initialFillValue to fill the buffer entries
+     */
+    public FloatCircularBuffer(int size, float initialFillValue)
+    {
+        mBuffer = new float[size];
+        Arrays.fill(mBuffer, initialFillValue);
+    }
 
-		Arrays.fill( mBuffer, (float)0.0 );
+    /**
-	}
+     * Creates a circular double buffer of the specified size and all entries filled with an initial value of zero.
+     *
+     * @param size of the buffer
+     */
+    public FloatCircularBuffer(int size)
+    {
+        this(size, 0.0f);
+    }
 
-	public int getSize()
+    public float[] getBuffer()
-	{
+    {
-		return mBuffer.length;
+        return mBuffer;
-	}
+    }
 
-	public float[] getBuffer()
+    /**
-	{
+     * Puts the new value into the buffer and returns the oldest buffer value that it replaced
-		return mBuffer;
+     *
-	}
+     * @param newValue to add to the buffer
+     * @return oldest value that was overwritten by the new value
+     */
+    public float get(float newValue)
+    {
+        float oldestSample = mBuffer[mBufferPointer];
 
-	/**
+        mBuffer[mBufferPointer] = newValue;
-	 * Puts the new value into the buffer and returns the oldest buffer value
-	 * that it replaced
-	 * @param newValue
-	 * @return
-	 */
-	public float get( float newValue )
-	{
-		float oldestSample = mBuffer[ mBufferPointer ];
 
-		mBuffer[ mBufferPointer ] = newValue;
+        mBufferPointer++;
 
-		mBufferPointer++;
+        if(mBufferPointer >= mBuffer.length)
+        {
+            mBufferPointer = 0;
+        }
 
-		if( mBufferPointer >= mBuffer.length )
+        return oldestSample;
-		{
+    }
-			mBufferPointer = 0;
-		}
 
-		return oldestSample;
+    public float[] getAll()
-	}
+    {
+        int valuePointer = 0;
+        float[] values = new float[mBuffer.length];
+        int bufferPointer = mBufferPointer;
 
-	/**
+        while(valuePointer < values.length)
-	 * Convenience method to put a new value in the buffer, while discarding
+        {
-	 * the old value
+            values[valuePointer++] = mBuffer[bufferPointer++];
-	 */
-	public void put( float newValue )
-	{
-		get( newValue );
-	}
 
-	/**
+            if(bufferPointer >= mBuffer.length)
-	 * Returns an array of arraySize, loaded with sampleCount of the 
+            {
-	 * oldest samples, loaded into the array starting at index 0.
+                bufferPointer = 0;
-	 * 
+            }
-	 * This is useful for fetching an array filled half way with samples to
+        }
-	 * use in FFT processing.
-	 * @param arraySize - size of the array (must be larger than sampleCount)
-	 * @param sampleCount - number of the oldest samples in the buffer to load
-	 * @return
-	 */
-	public float[] get( int arraySize, int sampleCount )
-	{
-		float[] samples = new float[ arraySize ];
 
-		if( arraySize > sampleCount )
+        return values;
-		{
+    }
-			int tempCounter = mBufferPointer;
 
-			for( int x = 0; x < sampleCount; x++ )
+    /**
-			{
+     * Places the new value into the buffer, overwriting the oldest value
-				samples[ x ] = mBuffer[ tempCounter ];
+     *
+     * @param newValue to add to the buffer
+     */
+    public void put(float newValue)
+    {
+        mBuffer[mBufferPointer] = newValue;
 
-				tempCounter++;
+        mBufferPointer++;
-				
-				if( tempCounter > mBuffer.length )
-				{
-					tempCounter = 0;
-				}
-			}
-		}
-		
-		return samples;
-	}
 
+        if(mBufferPointer >= mBuffer.length)
+        {
+            mBufferPointer = 0;
+        }
+    }
 }

src/main/java/io/github/dsheirer/dsp/filter/FilterFactory.java

@@ -666,11 +666,11 @@ public class FilterFactory
      * @param alpha - roll-off factor
      * @return - filter coefficients
      */
-    public static float[] getRootRaisedCosine(int samplesPerSymbol,
+    public static float[] getRootRaisedCosine(float samplesPerSymbol,
                                               int symbols,
                                               float alpha)
     {
-        int taps = samplesPerSymbol * symbols + 1;
+        int taps = (int)(samplesPerSymbol * (float)symbols + 1.0f);
 
         float scale = 0;
 
@@ -680,8 +680,8 @@ public class FilterFactory
         {
             float index = (float) x - ((float) taps / 2.0f);
 
-            float x1 = (float) Math.PI * index / (float) samplesPerSymbol;
+            float x1 = (float) Math.PI * index / samplesPerSymbol;
-            float x2 = 4.0f * alpha * index / (float) samplesPerSymbol;
+            float x2 = 4.0f * alpha * index / samplesPerSymbol;
             float x3 = x2 * x2 - 1.0f;
 
             float numerator, denominator;
@@ -692,7 +692,7 @@ public class FilterFactory
                 {
                     numerator = (float) Math.cos((1.0 + alpha) * x1) +
                         (float) Math.sin((1.0f - alpha) * x1) /
-                            (4.0f * alpha * index / (float) samplesPerSymbol);
+                            (4.0f * alpha * index / samplesPerSymbol);
                 }
                 else
                 {
@@ -713,9 +713,9 @@ public class FilterFactory
                 x3 = (1.0f - alpha) * x1;
                 x2 = (1.0f + alpha) * x1;
 
-                numerator = (float) (Math.sin(x2) * (1.0f + alpha) * Math.PI -
+                numerator = (float) (Math.sin(x2) * (1.0 + alpha) * Math.PI -
                     Math.cos(x3) * ((1.0 - alpha) * Math.PI *
-                        (double) samplesPerSymbol) / (4 * alpha * index) +
+                        (double) samplesPerSymbol) / (4.0 * alpha * index) +
                     Math.sin(x3) * (double) samplesPerSymbol *
                         (double) samplesPerSymbol / (4.0 * alpha * index * index));
 

src/main/java/io/github/dsheirer/dsp/filter/design/FilterView.java

@@ -12,155 +12,169 @@ import org.jtransforms.fft.FloatFFT_1D;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.net.URL;
+
 public class FilterView extends BorderPane
 {
-	private final static Logger mLog = LoggerFactory.getLogger( FilterView.class );
+    private final static Logger mLog = LoggerFactory.getLogger(FilterView.class);
 
-	private CurveFittedAreaChart mImpulseChart;
+    private CurveFittedAreaChart mImpulseChart;
-	private NumberAxis mImpulseXAxis;
+    private NumberAxis mImpulseXAxis;
-	private NumberAxis mImpulseYAxis;
+    private NumberAxis mImpulseYAxis;
-	private CurveFittedAreaChart mDFTChart;
+    private CurveFittedAreaChart mDFTChart;
-	private NumberAxis mDFTXAxis;
+    private NumberAxis mDFTXAxis;
-	private NumberAxis mDFTYAxis;
+    private NumberAxis mDFTYAxis;
-	private static final int FFT_SIZE = 4096;
+    private static final int FFT_SIZE = 4096;
-	private FloatFFT_1D mFFT = new FloatFFT_1D( FFT_SIZE );
+    private FloatFFT_1D mFFT = new FloatFFT_1D(FFT_SIZE);
 
-	public FilterView( float[] taps )
+    public FilterView(float[] taps)
-	{
+    {
-		init();
+        init();
 
-		if( taps != null )
+        if(taps != null)
-		{
+        {
-			setImpulseTaps( taps );
+            setImpulseTaps(taps);
 
-			float[] dft = new float[ FFT_SIZE ];
+            float[] dft = new float[FFT_SIZE];
-			System.arraycopy( taps, 0, dft, 0, taps.length );
+            System.arraycopy(taps, 0, dft, 0, taps.length);
 
-			mFFT.realForward( dft );
+            mFFT.realForward(dft);
 
-			setDFTTaps( convertDFTToDecibel( dft, taps.length ) );
+            setDFTTaps(convertDFTToDecibel(dft, taps.length));
-		}
+        }
-	}
+    }
 
-	private void init()
+    private void init()
-	{
+    {
-		HBox hbox = new HBox();
+        HBox hbox = new HBox();
 
-		mImpulseXAxis = new NumberAxis( 0.0, 0.5, 1.0 );
+        mImpulseXAxis = new NumberAxis(0.0, 0.5, 1.0);
-		mImpulseYAxis = new NumberAxis( -0.2, 1.2, .1 );
+        mImpulseYAxis = new NumberAxis(-0.2, 1.2, .1);
 
-		mImpulseChart = new CurveFittedAreaChart( mImpulseXAxis, mImpulseYAxis );
+        mImpulseChart = new CurveFittedAreaChart(mImpulseXAxis, mImpulseYAxis);
-		mImpulseChart.setLegendVisible( false );
+        mImpulseChart.setLegendVisible(false);
-		mImpulseChart.setHorizontalGridLinesVisible( false );
+        mImpulseChart.setHorizontalGridLinesVisible(false);
-		mImpulseChart.setVerticalGridLinesVisible(false);
+        mImpulseChart.setVerticalGridLinesVisible(false);
         mImpulseChart.setAlternativeColumnFillVisible(false);
         mImpulseChart.setAlternativeRowFillVisible(false);
 
-        String css = FilterView.class.getResource( "FilterView.css" ).toExternalForm();
+        URL cssURL = FilterView.class.getResource("FilterView.css");
-        mImpulseChart.getStylesheets().add( css );
 
-        hbox.getChildren().add( mImpulseChart );
+        String css = null;
-        HBox.setHgrow( mImpulseChart, Priority.ALWAYS );
 
-		mDFTXAxis = new NumberAxis( 0.0, FFT_SIZE / 2, FFT_SIZE / 8 );
+        if(cssURL != null)
-		mDFTYAxis = new NumberAxis( -200.0, 10.0, 10.0 );
-		
-		mDFTChart = new CurveFittedAreaChart( mDFTXAxis, mDFTYAxis );
-		mDFTChart.setLegendVisible( false );
-		mDFTChart.setHorizontalGridLinesVisible( false );
-		mDFTChart.setVerticalGridLinesVisible(false);
-        mDFTChart.setAlternativeColumnFillVisible(false);
-        mDFTChart.setAlternativeRowFillVisible(false);
-        mDFTChart.getStylesheets().add( css );
-        
-        hbox.getChildren().add( mDFTChart );
-        HBox.setHgrow( mDFTChart, Priority.ALWAYS );
-
-        setCenter( hbox );
-	}
-	
-	public void setImpulseTaps( double[] taps )
-	{
-		float[] convertedTaps = new float[ taps.length ];
-		
-		for( int x = 0; x < taps.length; x++ )
-		{
-			convertedTaps[ x ] = (float)taps[ x ];
-		}
-		
-		setImpulseTaps( convertedTaps );
-	}
-	
-	public void setImpulseTaps( float[] taps )
-	{
-		double smallest = 0.0;
-		double largest = 0.0;
-		
-        final XYChart.Series<Number, Number> series = new XYChart.Series<>();
-        
-        for( int x = 0; x < taps.length; x++ )
         {
-        	if( taps[ x ] < smallest )
+            css = cssURL.toExternalForm();
-			{
-        		smallest = taps[ x ];
-			}
 
-        	if( taps[ x ] > largest )
-        	{
-        		largest = taps[ x ];
-        	}
-
-        	series.getData().add( new XYChart.Data<Number, Number>( x, taps[ x ] ) );
         }
 
-        mImpulseXAxis.setLowerBound( 0.0 );
+        hbox.getChildren().add(mImpulseChart);
-        mImpulseXAxis.setUpperBound( taps.length - 1 );
+        HBox.setHgrow(mImpulseChart, Priority.ALWAYS);
-        mImpulseXAxis.setTickUnit( 1.0 );
 
-        double padding = Math.abs( largest - smallest ) * .1;
+        mDFTXAxis = new NumberAxis(0.0, FFT_SIZE / 2, FFT_SIZE / 8);
+        mDFTYAxis = new NumberAxis(-200.0, 10.0, 10.0);
 
-        mImpulseYAxis.setLowerBound( smallest - padding );
+        mDFTChart = new CurveFittedAreaChart(mDFTXAxis, mDFTYAxis);
-        mImpulseYAxis.setUpperBound( largest + padding );
+        mDFTChart.setLegendVisible(false);
-        mImpulseYAxis.setTickUnit( padding );
+        mDFTChart.setHorizontalGridLinesVisible(false);
+        mDFTChart.setVerticalGridLinesVisible(false);
+        mDFTChart.setAlternativeColumnFillVisible(false);
+        mDFTChart.setAlternativeRowFillVisible(false);
+
+        if(css != null)
+        {
+            mImpulseChart.getStylesheets().add(css);
+            mDFTChart.getStylesheets().add(css);
+        }
+
+        hbox.getChildren().add(mDFTChart);
+        HBox.setHgrow(mDFTChart, Priority.ALWAYS);
+
+        setCenter(hbox);
+    }
+
+    public void setImpulseTaps(double[] taps)
+    {
+        float[] convertedTaps = new float[taps.length];
+
+        for(int x = 0; x < taps.length; x++)
+        {
+            convertedTaps[x] = (float)taps[x];
+        }
+
+        setImpulseTaps(convertedTaps);
+    }
+
+    public void setImpulseTaps(float[] taps)
+    {
+        double smallest = 0.0;
+        double largest = 0.0;
+
+        final XYChart.Series<Number,Number> series = new XYChart.Series<>();
+
+        for(int x = 0; x < taps.length; x++)
+        {
+            if(taps[x] < smallest)
+            {
+                smallest = taps[x];
+            }
+
+            if(taps[x] > largest)
+            {
+                largest = taps[x];
+            }
+
+            series.getData().add(new XYChart.Data<Number,Number>(x, taps[x]));
+        }
+
+        mImpulseXAxis.setLowerBound(0.0);
+        mImpulseXAxis.setUpperBound(taps.length - 1);
+        mImpulseXAxis.setTickUnit(1.0);
+
+        double padding = Math.abs(largest - smallest) * .1;
+
+        mImpulseYAxis.setLowerBound(smallest - padding);
+        mImpulseYAxis.setUpperBound(largest + padding);
+        mImpulseYAxis.setTickUnit(padding);
 
         ObservableList<Series<Number,Number>> list = mImpulseChart.getData();
-        list.add( series );
+        list.add(series);
-	}
+    }
 
-	public void setDFTTaps( float[] taps )
+    public void setDFTTaps(float[] taps)
-	{
+    {
-		double smallest = 0.0;
+        double smallest = 0.0;
 
-        final XYChart.Series<Number, Number> series = new XYChart.Series<>();
+        final XYChart.Series<Number,Number> series = new XYChart.Series<>();
 
-        for( int x = 0; x < taps.length; x++ )
+        for(int x = 0; x < taps.length; x++)
         {
-        	if( taps[ x ] < smallest )
+            if(taps[x] < smallest)
-			{
+            {
-        		smallest = taps[ x ];
+                smallest = taps[x];
-			}
+            }
 
-        	series.getData().add( new XYChart.Data<Number, Number>( x, taps[ x ] ) );
+            series.getData().add(new XYChart.Data<Number,Number>(x, taps[x]));
         }
 
         ObservableList<Series<Number,Number>> list = mDFTChart.getData();
-        list.add( series );
+        list.add(series);
-	}
+    }
 
-    public float[] convertDFTToDecibel( float[] dft, int tapLength )
+    public float[] convertDFTToDecibel(float[] dft, int tapLength)
     {
-		float[] decibels = new float[ dft.length / 2 ];
+        float[] decibels = new float[dft.length / 2];
 
-		int index = 0;
+        int index = 0;
 
-		for( int x = 0; x < decibels.length; x ++ )
+        for(int x = 0; x < decibels.length; x++)
-		{
+        {
-			index = x * 2;
+            index = x * 2;
 
-			decibels[ x ] = 20.0f * (float)Math.log10( ( ( dft[ index ] * dft[ index ] ) + 
+            decibels[x] = 20.0f * (float)Math.log10(((dft[index] * dft[index]) +
-				  ( dft[ index + 1 ] * dft[ index + 1 ] ) ) );
+                (dft[index + 1] * dft[index + 1])));
-		}
+        }
 
-		return decibels;
+        return decibels;
     }
 }

src/main/java/io/github/dsheirer/dsp/filter/design/FilterViewer.java

@@ -39,15 +39,24 @@ public class FilterViewer extends Application
      */
     private float[] getFilter()
     {
+//        FIRFilterSpecification specification = FIRFilterSpecification.lowPassBuilder()
+//            .sampleRate(48000)
+//            .gridDensity(16)
+//            .passBandCutoff(2500)
+//            .passBandAmplitude(1.0)
+//            .passBandRipple(0.01)
+//            .stopBandStart(4000)
+//            .stopBandAmplitude(0.0)
+//            .stopBandRipple(0.008)
+//            .build();
         FIRFilterSpecification specification = FIRFilterSpecification.lowPassBuilder()
             .sampleRate(48000)
-            .gridDensity(16)
+            .passBandCutoff(5100)
-            .passBandCutoff(2500)
             .passBandAmplitude(1.0)
             .passBandRipple(0.01)
-            .stopBandStart(4000)
             .stopBandAmplitude(0.0)
-            .stopBandRipple(0.008)
+            .stopBandStart(6500)
+            .stopBandRipple(0.01)
             .build();
 
 //        FIRFilterSpecification specification = FIRFilterSpecification.highPassBuilder()
@@ -72,6 +81,9 @@ public class FilterViewer extends Application
 
         float[] taps = null;
 
+//        taps = FilterFactory.getSinc(6000, 1920, 47, Window.WindowType.BLACKMAN);
+
+//        taps = FilterFactory.getRootRaisedCosine(10, 10, 0.2f);
 //        taps = FilterFactory.getLowPass(48000, 6750, 7500, 60,
 //            Window.WindowType.HAMMING, true);
 

src/main/java/io/github/dsheirer/dsp/filter/fir/complex/ComplexFIRFilter.java

@@ -1,54 +1,90 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.filter.fir.complex;
 
 import io.github.dsheirer.dsp.filter.fir.FIRFilter;
 import io.github.dsheirer.dsp.filter.fir.real.RealFIRFilter;
 import io.github.dsheirer.sample.complex.Complex;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
 
 public class ComplexFIRFilter extends FIRFilter
 {
-	private RealFIRFilter mIFilter;
+    private RealFIRFilter mIFilter;
-	private RealFIRFilter mQFilter;
+    private RealFIRFilter mQFilter;
 
-	/**
+    /**
-	 * Complex FIR Filter for processing complex sample pairs.  Wraps two real
+     * Complex FIR Filter for processing complex sample pairs.  Wraps two real
-	 * FIR filters for processing each of the inphase and quadrature samples.
+     * FIR filters for processing each of the inphase and quadrature samples.
-	 * 
+     *
-	 * @param coefficients - filter taps
+     * @param coefficients - filter taps
-	 * @param gain - gain to apply to filtered outputs - use 1.0f for no gain
+     * @param gain - gain to apply to filtered outputs - use 1.0f for no gain
-	 */
+     */
-	public ComplexFIRFilter( float[] coefficients, float gain )
+    public ComplexFIRFilter(float[] coefficients, float gain)
-	{
+    {
-		mIFilter = new RealFIRFilter( coefficients, gain );
+        mIFilter = new RealFIRFilter(coefficients, gain);
-		mQFilter = new RealFIRFilter( coefficients, gain );
+        mQFilter = new RealFIRFilter(coefficients, gain);
-	}
+    }
 
-	public float[] getCoefficients()
+    public float[] getCoefficients()
-	{
+    {
-		return mIFilter.getCoefficients();
+        return mIFilter.getCoefficients();
-	}
+    }
 
-	public float filterInphase( float sample )
+    public float filterInphase(float sample)
-	{
+    {
-		return mIFilter.filter( sample );
+        return mIFilter.filter(sample);
-	}
+    }
 
-	public float filterQuadrature( float sample )
+    public float filterQuadrature(float sample)
-	{
+    {
-		return mQFilter.filter( sample );
+        return mQFilter.filter(sample);
-	}
+    }
 
-	public Complex filter( Complex sample )
+    public Complex filter(Complex sample)
-	{
+    {
-		float i = filterInphase( sample.inphase() );
+        float i = filterInphase(sample.inphase());
-		float q = filterQuadrature( sample.quadrature() );
+        float q = filterQuadrature(sample.quadrature());
 
-		return new Complex( i, q );
+        return new Complex(i, q);
-	}
+    }
 
-	@Override
+    /**
-	public void dispose()
+     * Filters the complex samples from the buffer and returns a new complex buffer with the filtered output
-	{
+     *
-		mIFilter.dispose();
+     * @param buffer with complex samples to filter
-		mQFilter.dispose();
+     * @return new buffer containing filtered complex samples
-	}
+     */
+    public ComplexBuffer filter(ComplexBuffer buffer)
+    {
+        float[] samples = buffer.getSamples();
+        float[] filtered = new float[samples.length];
+
+        for(int x = 0; x < samples.length; x += 2)
+        {
+            filtered[x] = filterInphase(samples[x]);
+            filtered[x + 1] = filterQuadrature(samples[x + 1]);
+        }
+
+        return new ComplexBuffer(filtered);
+    }
+
+    @Override
+    public void dispose()
+    {
+        mIFilter.dispose();
+        mQFilter.dispose();
+    }
 }

src/main/java/io/github/dsheirer/dsp/filter/fir/complex/ComplexFIRFilter_CB_CB.java

@@ -3,8 +3,7 @@ package io.github.dsheirer.dsp.filter.fir.complex;
 import io.github.dsheirer.sample.Listener;
 import io.github.dsheirer.sample.complex.ComplexBuffer;
 
-public class ComplexFIRFilter_CB_CB extends ComplexFIRFilter 
+public class ComplexFIRFilter_CB_CB extends ComplexFIRFilter implements Listener<ComplexBuffer>
-				implements Listener<ComplexBuffer>
 {
 	private Listener<ComplexBuffer> mListener;
 	

src/main/java/io/github/dsheirer/dsp/filter/interpolator/RealInterpolator.java

@@ -5,54 +5,86 @@ import org.apache.commons.lang3.Validate;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.text.DecimalFormat;
+import java.util.Arrays;
+
 public class RealInterpolator extends Interpolator
 {
-	private final static Logger mLog = LoggerFactory.getLogger( RealInterpolator.class );
+    private final static Logger mLog = LoggerFactory.getLogger(RealInterpolator.class);
 
-	private float mGain;
+    private float mGain;
 
-	public RealInterpolator( float gain )
+    /**
-	{
+     * Provides an interpolated sample point along an eight-sample waveform representation using 128 filters to
-		mGain = gain;
+     * provide approximate interpolation with a resolution of 1/128th of a sample.
-	}
+     *
-	/**
+     * @param gain to apply to the interpolated sample
-	 * Calculates an interpolated value from the 8 samples beginning at the 
+     */
-	 * offset index.  Uses the mu value to determine which of 128 filter kernels
+    public RealInterpolator(float gain)
-	 * to use in order to closely approximate the ideal frequency response for 
+    {
-	 * the value of mu, ranging from 0.0 to 1.0, indicating the interpolated
+        mGain = gain;
-	 * position in the sample set ranging from offset to offset + 7.
+    }
-	 * 
-	 * @param samples - sample array of length at least offset + 7
-	 * 
-	 * @param mu - interpolated sample position between 0 and 1.0
-	 * 
-	 * @return - interpolated sample value
-	 */
-	public float filter( float[] samples, int offset, float mu )
-	{
-		/* Ensure we have enough samples in the array */
-		Validate.isTrue(samples.length >= offset + 7);
 
-		/* Identify the filter bank that corresponds to mu */
+    /**
-		int index = (int)( NSTEPS * mu );
+     * Calculates an interpolated value from eight samples that start at the offset into the sample array.  The
+     * interpolated sample will fall within the middle of the eight sample array, between indexes offset+3 and
+     * offset+4.  The mu argument is translated into an index position between 0 and 128, where a mu of 0.0 will be
+     * converted to index zero and will be equal to the sample at index offset+3 and a mu of 1.0 will be equal to
+     * the sample at offset+4.  All mu values between 0.0 and 1.0 will be converted to a 1 - 127 index and will
+     * produce an approximated value from among 127 interpolated sample points between indexes offset+3 and offset+4.
+     *
+     * @param samples - sample array of length at least offset + 7
+     * @param mu - interpolated sample position between 0.0 and 1.0
+     * @return - interpolated sample value
+     */
+    public float filter(float[] samples, int offset, float mu)
+    {
+        /* Ensure we have enough samples in the array */
+        Validate.isTrue(samples.length >= offset + 7);
 
-		float accumulator = ( TAPS[ index ][ 7 ] * samples[ offset ] );
+        /* Identify the filter bank that corresponds to mu */
-		accumulator += ( TAPS[ index ][ 6 ] * samples[ offset + 1 ] );
+        int index = (int)(NSTEPS * mu);
-		accumulator += ( TAPS[ index ][ 5 ] * samples[ offset + 2 ] );
-		accumulator += ( TAPS[ index ][ 4 ] * samples[ offset + 3 ] );
-		accumulator += ( TAPS[ index ][ 3 ] * samples[ offset + 4 ] );
-		accumulator += ( TAPS[ index ][ 2 ] * samples[ offset + 5 ] );
-		accumulator += ( TAPS[ index ][ 1 ] * samples[ offset + 6 ] );
-		accumulator += ( TAPS[ index ][ 0 ] * samples[ offset + 7 ] );
 
-		return accumulator * mGain;
+        float accumulator = (TAPS[index][7] * samples[offset]);
-	}
+        accumulator += (TAPS[index][6] * samples[offset + 1]);
+        accumulator += (TAPS[index][5] * samples[offset + 2]);
+        accumulator += (TAPS[index][4] * samples[offset + 3]);
+        accumulator += (TAPS[index][3] * samples[offset + 4]);
+        accumulator += (TAPS[index][2] * samples[offset + 5]);
+        accumulator += (TAPS[index][1] * samples[offset + 6]);
+        accumulator += (TAPS[index][0] * samples[offset + 7]);
 
-	public Complex filter( float[] iSamples, float[] qSamples, int offset, float mu )
+        return accumulator * mGain;
-	{
+    }
-		float i = filter( iSamples, offset, mu );
-		float q = filter( qSamples, offset, mu );
 
-		return new Complex( i, q );
+    public Complex filter(float[] iSamples, float[] qSamples, int offset, float mu)
-	}
+    {
+        float i = filter(iSamples, offset, mu);
+        float q = filter(qSamples, offset, mu);
+
+        return new Complex(i, q);
+    }
+
+    public static void main(String[] args)
+    {
+        RealInterpolator interpolator = new RealInterpolator(1.0f);
+        DecimalFormat decimalFormat = new DecimalFormat("0.0000");
+
+        double TWO_PI = Math.PI * 2.0;
+
+		float[] samples = new float[16];
+
+		for(int x = 0; x < 16; x++)
+        {
+            samples[x] = (float)Math.sin(TWO_PI * (double)x / 8.0);
+        }
+
+        mLog.debug("Samples: " + Arrays.toString(samples));
+
+        for(float x = 0.0f; x <= 1.01f; x += 0.1f)
+        {
+            mLog.debug(decimalFormat.format(x) + ": " + decimalFormat.format(interpolator.filter(samples, 1, x)));
+        }
+
+    }
 }

src/main/java/io/github/dsheirer/dsp/fm/FMDemodulator.java

@@ -17,62 +17,87 @@
  ******************************************************************************/
 package io.github.dsheirer.dsp.fm;
 
+import io.github.dsheirer.sample.complex.Complex;
+
 public abstract class FMDemodulator
 {
-	private float mPreviousI = 0.0f;
+    private float mPreviousI = 0.0f;
-	private float mPreviousQ = 0.0f;
+    private float mPreviousQ = 0.0f;
-	protected float mGain;
+    protected float mGain;
 
-	public FMDemodulator( float gain )
+    public FMDemodulator(float gain)
-	{
+    {
-		mGain = gain;
+        mGain = gain;
-	}
+    }
 
-	public float demodulate( float currentI, float currentQ )
+    public float demodulate(float currentI, float currentQ)
-	{
+    {
-		/**
+        /**
-		 * Multiply the current sample against the complex conjugate of the
+         * Multiply the current sample against the complex conjugate of the
-		 * previous sample to derive the phase delta between the two samples
+         * previous sample to derive the phase delta between the two samples
-		 * 
+         *
-		 * Negating the previous sample quadrature produces the conjugate
+         * Negating the previous sample quadrature produces the conjugate
-		 */
+         */
-		double inphase = ( currentI * mPreviousI ) - ( currentQ * -mPreviousQ );
+        double inphase = (currentI * mPreviousI) - (currentQ * -mPreviousQ);
-		double quadrature = ( currentQ * mPreviousI ) + ( currentI * -mPreviousQ );
+        double quadrature = (currentQ * mPreviousI) + (currentI * -mPreviousQ);
 
-		double angle = 0.0f;
+        double angle = 0.0f;
 
-		//Check for divide by zero
+        //Check for divide by zero
-		if( inphase != 0 )
+        if(inphase != 0)
-		{
+        {
-			/**
+            /**
-			 * Use the arc-tangent of quadrature divided by inphase to
+             * Use the arc-tangent of quadrature divided by inphase to
-			 * get the phase angle (+/-) which was directly manipulated by the
+             * get the phase angle (+/-) which was directly manipulated by the
-			 * original message waveform during the modulation.  This value now
+             * original message waveform during the modulation.  This value now
-			 * serves as the instantaneous amplitude of the demodulated signal
+             * serves as the instantaneous amplitude of the demodulated signal
-			 */
+             */
-			double denominator = 1.0d / inphase;
+            double denominator = 1.0d / inphase;
-			angle = Math.atan( (double)quadrature * denominator );
+            angle = Math.atan((double)quadrature * denominator);
-		}
+        }
 
-		/**
+        /**
-		 * Store the current sample to use during the next iteration
+         * Store the current sample to use during the next iteration
-		 */
+         */
-		mPreviousI = currentI;
+        mPreviousI = currentI;
-		mPreviousQ = currentQ;
+        mPreviousQ = currentQ;
 
-		return (float)( angle * mGain );
+        return (float)(angle * mGain);
-	}
+    }
 
-	public abstract void dispose();
+    public static double demodulate(Complex previous, Complex current)
+    {
+        double inphase = (current.inphase() * previous.inphase()) - (current.quadrature() * -previous.quadrature());
+        double quadrature = (current.quadrature() * previous.inphase()) + (current.inphase() * -previous.quadrature());
 
-	public void reset()
+        double angle = 0.0f;
-	{
-		mPreviousI = 0.0f;
-		mPreviousQ = 0.0f;
-	}
 
-	public void setGain( float gain )
+        //Check for divide by zero
-	{
+        if(inphase != 0)
-		mGain = gain;
+        {
-	}
+            /**
+             * Use the arc-tangent of quadrature divided by inphase to
+             * get the phase angle (+/-) which was directly manipulated by the
+             * original message waveform during the modulation.  This value now
+             * serves as the instantaneous amplitude of the demodulated signal
+             */
+            double denominator = 1.0d / inphase;
+            angle = Math.atan((double)quadrature * denominator);
+        }
+
+        return angle;
+    }
+
+    public abstract void dispose();
+
+    public void reset()
+    {
+        mPreviousI = 0.0f;
+        mPreviousQ = 0.0f;
+    }
+
+    public void setGain(float gain)
+    {
+        mGain = gain;
+    }
 }

src/main/java/io/github/dsheirer/dsp/fm/FMDemodulator_CB.java

@@ -26,8 +26,7 @@ import org.slf4j.LoggerFactory;
 
 public class FMDemodulator_CB extends FMDemodulator implements Listener<ComplexBuffer>
 {
-	private final static Logger mLog = 
+	private final static Logger mLog = LoggerFactory.getLogger( FMDemodulator_CB.class );
-			LoggerFactory.getLogger( FMDemodulator_CB.class );
 
 	private Listener<RealBuffer> mListener;
 	

src/main/java/io/github/dsheirer/dsp/gain/ComplexFeedForwardGainControl.java

@@ -1,112 +1,125 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.gain;
 
 import io.github.dsheirer.buffer.FloatCircularBuffer;
 import io.github.dsheirer.sample.complex.Complex;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
 import io.github.dsheirer.sample.complex.ComplexSampleListener;
 
-/*******************************************************************************
- *     SDR Trunk 
- *     Copyright (C) 2015 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/>
- *     
- *     This class is modeled using concepts detailed in the GNURadio 
- *     implementation of feed forward AGC class located at:
- *     https://github.com/gnuradio/gnuradio/blob/master/gr-analog/lib/
- *     feedforward_agc_cc_impl.cc
- *     
- ******************************************************************************/
 public class ComplexFeedForwardGainControl implements ComplexSampleListener
 {
-	public static final float OBJECTIVE_ENVELOPE = 1.0f;
+    public static final float OBJECTIVE_ENVELOPE = 1.0f;
-	public static final float MINIMUM_ENVELOPE = 0.0001f;
+    public static final float MINIMUM_ENVELOPE = 0.0001f;
 
-	private ComplexSampleListener mListener;
+    private ComplexSampleListener mListener;
 
-	private FloatCircularBuffer mEnvelopeHistory;
+    private FloatCircularBuffer mEnvelopeHistory;
 
-	private float mMaxEnvelope = 0.0f;
+    private float mMaxEnvelope = 0.0f;
-	private float mGain = 1.0f;
+    private float mGain = 1.0f;
 
-	/**
+    /**
-	 * Dynamic gain control for incoming sample stream to amplify or attenuate
+     * Dynamic gain control for incoming sample stream to amplify or attenuate
-	 * all samples toward an objective unity)gain, using the maximum envelope 
+     * all samples toward an objective unity)gain, using the maximum envelope
-	 * value detected in the stream history window.  
+     * value detected in the stream history window.
-	 * 
+     *
-	 * Uses the specified damping factor to limit gain swings.  Damping factor
+     * Uses the specified damping factor to limit gain swings.  Damping factor
-	 * is applied against the delta between current gain value and a recalculated
+     * is applied against the delta between current gain value and a recalculated
-	 * gain value to limit how quickly the gain value will increase or decrease.
+     * gain value to limit how quickly the gain value will increase or decrease.
-	 * 
+     *
-	 * @param window - history size to use in detecting maximum envelope value
+     * @param window - history size to use in detecting maximum envelope value
-	 * @param damping - a value between 0 < damping <= 1.0;
+     */
-	 */
+    public ComplexFeedForwardGainControl(int window)
-	public ComplexFeedForwardGainControl( int window )
+    {
-	{
+        mEnvelopeHistory = new FloatCircularBuffer(window);
-		mEnvelopeHistory = new FloatCircularBuffer( window );
+    }
-	}
 
-	public void dispose()
+    public void dispose()
-	{
+    {
-		mListener = null;
+        mListener = null;
-	}
+    }
 
-	@Override
+    @Override
-	public void receive( float inphase, float quadrature )
+    public void receive(float inphase, float quadrature)
-	{
+    {
-		float envelope = Complex.envelope( inphase, quadrature );
+        process(inphase, quadrature);
 
-		if( envelope > mMaxEnvelope )
+        /* Apply current gain value to the sample and send to the listener */
-		{
+        if(mListener != null)
-			mMaxEnvelope = envelope;
+        {
+            mListener.receive(inphase *= mGain, quadrature *= mGain);
+        }
+    }
 
-			adjustGain();
+    private void process(float inphase, float quadrature)
-		}
+    {
+        float envelope = Complex.envelope(inphase, quadrature);
 
-		/* Replace oldest envelope value with current envelope value */
+        if(envelope > mMaxEnvelope)
-		float oldestEnvelope = mEnvelopeHistory.get( envelope );
+        {
+            mMaxEnvelope = envelope;
 
-		/* If the oldest envelope value was the max envelope value, then we 
+            adjustGain();
-		 * have to rediscover the max value from the envelope history */
+        }
-		if( mMaxEnvelope == oldestEnvelope && mMaxEnvelope != envelope )
-		{
-			mMaxEnvelope = MINIMUM_ENVELOPE;
 
-			for( float value: mEnvelopeHistory.getBuffer() )
+        /* Replace oldest envelope value with current envelope value */
-			{
+        float oldestEnvelope = mEnvelopeHistory.get(envelope);
-				if( value > mMaxEnvelope )
-				{
-					mMaxEnvelope = value;
-				}
-			}
 
-			adjustGain();
+        /* If the oldest envelope value was the max envelope value, then we
-		}
+         * have to rediscover the max value from the envelope history */
+        if(mMaxEnvelope == oldestEnvelope && mMaxEnvelope != envelope)
+        {
+            mMaxEnvelope = MINIMUM_ENVELOPE;
 
-		/* Apply current gain value to the sample and send to the listener */
+            for(float value : mEnvelopeHistory.getBuffer())
-		if( mListener != null )
+            {
-		{
+                if(value > mMaxEnvelope)
-			mListener.receive( inphase *= mGain, quadrature *= mGain );
+                {
-		}
+                    mMaxEnvelope = value;
-	}
+                }
+            }
 
-	private void adjustGain()
+            adjustGain();
-	{
+        }
-		mGain = OBJECTIVE_ENVELOPE / mMaxEnvelope;
+    }
-	}
 
-	public void setListener( ComplexSampleListener listener )
+    private void adjustGain()
-	{
+    {
-		mListener = listener;
+        mGain = OBJECTIVE_ENVELOPE / mMaxEnvelope;
-	}
+    }
+
+    public void setListener(ComplexSampleListener listener)
+    {
+        mListener = listener;
+    }
+
+    public ComplexBuffer filter(ComplexBuffer complexBuffer)
+    {
+        float[] samples = complexBuffer.getSamples();
+        float[] processed = new float[samples.length];
+
+        for(int x = 0; x < samples.length; x += 2)
+        {
+            process(samples[x], samples[x + 1]);
+
+            processed[x] = samples[x] * mGain;
+            processed[x + 1] = samples[x + 1] * mGain;
+        }
+
+        return new ComplexBuffer(processed);
+    }
 }

src/main/java/io/github/dsheirer/dsp/gain/ComplexGain.java

@@ -5,27 +5,34 @@ import io.github.dsheirer.sample.complex.Complex;
 
 public class ComplexGain implements Listener<Complex>
 {
-	private float mGain;
+    private float mGain;
-	private Listener<Complex> mListener;
+    private Listener<Complex> mListener;
 
-	public ComplexGain( float gain )
+    public ComplexGain(float gain)
-	{
+    {
-		mGain = gain;
+        mGain = gain;
-	}
+    }
 
-	@Override
+    public Complex apply(Complex sample)
-	public void receive( Complex sample )
+    {
-	{
+        sample.multiply(mGain);
-		if( mListener != null )
-		{
-			sample.multiply( mGain );
 
-			mListener.receive( sample );
+        return sample;
-		}
+    }
-	}
 
-	public void setListener( Listener<Complex> listener )
+    @Override
-	{
+    public void receive(Complex sample)
-		mListener = listener;
+    {
-	}
+        if(mListener != null)
+        {
+            apply(sample);
+
+            mListener.receive(sample);
+        }
+    }
+
+    public void setListener(Listener<Complex> listener)
+    {
+        mListener = listener;
+    }
 }

src/main/java/io/github/dsheirer/dsp/mixer/Oscillator.java

@@ -51,8 +51,7 @@ public class Oscillator
 	 */
 	private void update()
 	{
-		float anglePerSample = 
+		float anglePerSample = (float)( 2.0d * Math.PI * mFrequency / mSampleRate );
-				(float)( 2.0d * Math.PI * mFrequency / mSampleRate );
 
 		mAnglePerSample = Complex.fromAngle( anglePerSample );
 	}

src/main/java/io/github/dsheirer/dsp/psk/DQPSKDemodulator.java

@@ -0,0 +1,162 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.dsp.psk.pll.IPhaseLockedLoop;
+import io.github.dsheirer.dsp.symbol.Dibit;
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.Complex;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
+import io.github.dsheirer.sample.complex.ComplexSampleListener;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class DQPSKDemodulator implements ComplexSampleListener
+{
+    private final static Logger mLog = LoggerFactory.getLogger(DQPSKDemodulator.class);
+    protected InterpolatingSampleBuffer mInterpolatingSampleBuffer;
+    protected IPhaseLockedLoop mPLL;
+    protected DQPSKSymbolEvaluator mSymbolEvaluator = new DQPSKSymbolEvaluator();
+    private Complex mReceivedSample = new Complex(0, 0);
+    private Complex mPreviousPrecedingSample = new Complex(0, 0);
+    private Complex mPreviousCurrentSample = new Complex(0, 0);
+    private Complex mPrecedingSample = new Complex(0, 0);
+    private Complex mCurrentSample = new Complex(0, 0);
+    private Complex mPrecedingSymbol = new Complex(0, 0);
+    protected Complex mCurrentSymbol = new Complex(0, 0);
+    private Listener<Dibit> mDibitListener;
+
+    /**
+     * Decoder for Differential Quaternary Phase Shift Keying (DQPSK).  This decoder uses both a Costas Loop (PLL) and
+     * a custom DQPSK symbol timing error detector to automatically align to the incoming carrier frequency and to
+     * adjust for any changes in symbol timing.
+     *
+     * This detector is optimized for constant amplitude DQPSK symbols like C4FM.
+     *
+     * @param phaseLockedLoop for tracking carrier frequency error
+     * @param interpolatingSampleBuffer to hold samples for interpolating a symbol
+     */
+    public DQPSKDemodulator(IPhaseLockedLoop phaseLockedLoop, InterpolatingSampleBuffer interpolatingSampleBuffer)
+    {
+        mPLL = phaseLockedLoop;
+        mInterpolatingSampleBuffer = interpolatingSampleBuffer;
+    }
+
+    /**
+     * Processes a (filtered) buffer containing complex samples for decoding
+     * @param complexBuffer with complex samples
+     */
+    public void receive(ComplexBuffer complexBuffer)
+    {
+        float[] samples = complexBuffer.getSamples();
+
+        for(int x = 0; x < samples.length; x += 2)
+        {
+            receive(samples[x], samples[x + 1]);
+        }
+    }
+
+    /**
+     * Processes a complex sample for decoding.  Once sufficient samples are buffered, a symbol decision is made.
+     * @param inphase value for the sample
+     * @param quadrature value for the sample
+     */
+    @Override
+    public void receive(float inphase, float quadrature)
+    {
+        //Update current sample with values
+        mReceivedSample.setValues(inphase, quadrature);
+
+        //Mix current sample with costas loop to remove any rotation that is present from a mis-tuned carrier frequency
+        mReceivedSample.multiply(mPLL.incrementAndGetCurrentVector());
+
+        //Store the sample in the interpolating buffer
+        mInterpolatingSampleBuffer.receive(mReceivedSample);
+
+        //Calculate the symbol once we've stored enough samples
+        if(mInterpolatingSampleBuffer.hasSymbol())
+        {
+            calculateSymbol();
+        }
+    }
+
+    /**
+     * Calculates a symbol from the interpolating buffer
+     */
+    protected void calculateSymbol()
+    {
+        //Get preceding sample and an interpolated current sample from the interpolating buffer
+        mPrecedingSample = mInterpolatingSampleBuffer.getPrecedingSample();
+        mCurrentSample = mInterpolatingSampleBuffer.getCurrentSample();
+
+        //Calculate preceding, current and following symbols as the delta rotation compared to the previous samples
+        mPrecedingSymbol.setInphase(Complex.multiplyInphase(mPrecedingSample.inphase(), mPrecedingSample.quadrature(),
+            mPreviousPrecedingSample.inphase(), -mPreviousPrecedingSample.quadrature()));
+        mPrecedingSymbol.setQuadrature(Complex.multiplyQuadrature(mPrecedingSample.inphase(), mPrecedingSample.quadrature(),
+            mPreviousPrecedingSample.inphase(), -mPreviousPrecedingSample.quadrature()));
+
+        mCurrentSymbol.setInphase(Complex.multiplyInphase(mCurrentSample.inphase(), mCurrentSample.quadrature(),
+            mPreviousCurrentSample.inphase(), -mPreviousCurrentSample.quadrature()));
+        mCurrentSymbol.setQuadrature(Complex.multiplyQuadrature(mCurrentSample.inphase(), mCurrentSample.quadrature(),
+            mPreviousCurrentSample.inphase(), -mPreviousCurrentSample.quadrature()));
+
+        //Set gain to unity before we calculate the error value
+        mPrecedingSymbol.normalize();
+        mCurrentSymbol.normalize();
+
+        mSymbolEvaluator.setSymbol(mPrecedingSymbol, mCurrentSymbol);
+
+        mInterpolatingSampleBuffer.resetAndAdjust(mSymbolEvaluator.getTimingError());
+
+        //Store current samples/symbols to use for the next period
+        mPreviousPrecedingSample.setValues(mPrecedingSample);
+        mPreviousCurrentSample.setValues(mCurrentSample);
+
+        //Calculate the phase error of the current symbol relative to the expected constellation and provide
+        //feedback to the PLL
+        mPLL.adjust(clip(mSymbolEvaluator.getPhaseError(), 0.5f));
+
+        if(mDibitListener != null)
+        {
+            mDibitListener.receive(mSymbolEvaluator.getSymbolDecision());
+        }
+    }
+
+    /**
+     * Registers the listener to receive dibit symbol decisions from this demodulator
+     */
+    public void setDibitListener(Listener<Dibit> listener)
+    {
+        mDibitListener = listener;
+    }
+
+    /**
+     * Constrains value to the range of ( -maximum <> maximum )
+     */
+    public static float clip(float value, float maximum)
+    {
+        if(value > maximum)
+        {
+            return maximum;
+        }
+        else if(value < -maximum)
+        {
+            return -maximum;
+        }
+
+        return value;
+    }
+}

src/main/java/io/github/dsheirer/dsp/psk/DQPSKDemodulatorInstrumented.java

@@ -0,0 +1,131 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.dsp.psk.pll.CostasLoop;
+import io.github.dsheirer.dsp.psk.pll.IPhaseLockedLoop;
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.Complex;
+
+public class DQPSKDemodulatorInstrumented extends DQPSKDemodulator
+{
+    private Listener<SymbolDecisionData> mSymbolDecisionDataListener;
+    private Listener<Double> mSamplesPerSymbolListener;
+    private Listener<Complex> mSymbolListener;
+    private Listener<Double> mPLLErrorListener;
+    private Listener<Double> mPLLFrequencyListener;
+    private double mSampleRate;
+
+    /**
+     * Decoder for Differential Quaternary Phase Shift Keying (DQPSK).  This decoder uses both a Costas Loop (PLL) and
+     * a custom DQPSK symbol timing error detector to automatically align to the incoming carrier frequency and to
+     * adjust for any changes in symbol timing.
+     *
+     * This detector is optimized for constant amplitude DQPSK symbols like C4FM.
+     *
+     * @param phaseLockedLoop for tracking carrier frequency error
+     * @param interpolatingSampleBuffer
+     * @param sampleRate of the incoming complex sample stream
+     */
+    public DQPSKDemodulatorInstrumented(IPhaseLockedLoop phaseLockedLoop,
+                                        InterpolatingSampleBufferInstrumented interpolatingSampleBuffer,
+                                        double sampleRate)
+    {
+        super(phaseLockedLoop, interpolatingSampleBuffer);
+        mSampleRate = sampleRate;
+    }
+
+    /**
+     * Overrides the parent class symbol calculation to capture eye diagram data
+     */
+    protected void calculateSymbol()
+    {
+        //Eye diagram listener
+        if(mSymbolDecisionDataListener != null)
+        {
+            mSymbolDecisionDataListener.receive(
+                ((InterpolatingSampleBufferInstrumented)mInterpolatingSampleBuffer).getSymbolDecisionData());
+        }
+
+        super.calculateSymbol();
+
+        if(mSamplesPerSymbolListener != null)
+        {
+            mSamplesPerSymbolListener.receive((double)mInterpolatingSampleBuffer.getSamplingPoint());
+        }
+
+        //Send to an external constellation symbol listener when registered
+        if(mSymbolListener != null)
+        {
+            mSymbolListener.receive(mCurrentSymbol);
+        }
+
+        if(mPLLErrorListener != null)
+        {
+            mPLLErrorListener.receive((double)mSymbolEvaluator.getPhaseError());
+        }
+
+        if(mPLLFrequencyListener != null)
+        {
+            double loopFrequency = ((CostasLoop)mPLL).getLoopFrequency();
+
+            loopFrequency *= mSampleRate / (2.0 * Math.PI);
+
+            mPLLFrequencyListener.receive(loopFrequency);
+        }
+    }
+
+    /**
+     * Registers a listener to receive symbol decision data to produce an eye diagram.
+     */
+    public void setSymbolDecisionDataListener(Listener<SymbolDecisionData> listener)
+    {
+        mSymbolDecisionDataListener = listener;
+    }
+
+    /**
+     * Registers the listener to receive PLL error values
+     */
+    public void setSamplesPerSymbolListener(Listener<Double> listener)
+    {
+        mSamplesPerSymbolListener = listener;
+    }
+
+    /**
+     * Registers the listener to receive decoded QPSK symbols
+     */
+    public void setSymbolListener(Listener<Complex> listener)
+    {
+        mSymbolListener = listener;
+    }
+
+    /**
+     * Registers the listener to receive PLL error values
+     */
+    public void setPLLErrorListener(Listener<Double> listener)
+    {
+        mPLLErrorListener = listener;
+    }
+
+    /**
+     * Registers the listener to receive PLL error values
+     */
+    public void setPLLFrequencyListener(Listener<Double> listener)
+    {
+        mPLLFrequencyListener = listener;
+    }
+
+}

src/main/java/io/github/dsheirer/dsp/psk/DQPSKSymbolEvaluator.java

@@ -0,0 +1,137 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.dsp.symbol.Dibit;
+import io.github.dsheirer.sample.complex.Complex;
+
+public class DQPSKSymbolEvaluator implements IDQPSKSymbolEvaluator
+{
+    private static final Complex ROTATE_FROM_PLUS_135 = Complex.fromAngle(-3.0 * Math.PI / 4.0);
+    private static final Complex ROTATE_FROM_PLUS_45 = Complex.fromAngle(-1.0 * Math.PI / 4.0);
+    private static final Complex ROTATE_FROM_MINUS_45 = Complex.fromAngle(1.0 * Math.PI / 4.0);
+    private static final Complex ROTATE_FROM_MINUS_135 = Complex.fromAngle(3.0 * Math.PI / 4.0);
+
+    private Complex mSymbolError = new Complex(0, 0);
+    private float mPhaseError = 0.0f;
+    private float mTimingError = 0.0f;
+    private float mTimingErrorPolarity = 1.0f;
+    private Dibit mSymbolDecision = Dibit.D00_PLUS_1;
+
+    /**
+     * Decision-directed symbol phase and timing error detector and symbol decision slicer.
+     *
+     * Symbol decision is based on the closest reference quadrant for the sampled symbol.
+     *
+     * Phase and timing error are calculated as the angular distance of the sampled symbol from the reference
+     * symbol.  Timing error is further corrected to compensate for clock-wise or counter-clock-wise vector rotation
+     * relative to the immediately preceding symbol.
+     */
+    public DQPSKSymbolEvaluator()
+    {
+    }
+
+    /**
+     * Sets the preceding and current symbols to be evaluated for phase and timing errors and to determine the
+     * transmitted symbol relative to the closest reference symbol.  After invoking this method, you can access the
+     * phase and timing errors and the symbol decision via their respective accessor methods.
+     *
+     * Phase and timing error values are calculated by first determining the symbol and then calculating the phase
+     * and timing errors relative to the reference symbol.  The timing error is corrected with the appropriate sign
+     * relative to the angular vector rotation so that the error value indicates the correct error direction.
+     *
+     * @param preceding differential-decoded sample/symbol used to detect rotation - does NOT need to be interpolated
+     * since it's only a reference
+     * @param current symbol to be evaluated - interpolated
+     */
+    @Override
+    public void setSymbol(Complex preceding, Complex current)
+    {
+        mSymbolError.setValues(current);
+
+        if(mSymbolError.quadrature() > 0.0f)
+        {
+            if(mSymbolError.inphase() > 0.0f)
+            {
+                mSymbolDecision = Dibit.D00_PLUS_1;
+                mTimingErrorPolarity = (preceding.quadrature() > current.quadrature() ? 1.0f : -1.0f);
+                mSymbolError.multiply(ROTATE_FROM_PLUS_45);
+            }
+            else
+            {
+                mSymbolDecision = Dibit.D01_PLUS_3;
+                mTimingErrorPolarity = (preceding.quadrature() < current.quadrature() ? 1.0f : -1.0f);
+                mSymbolError.multiply(ROTATE_FROM_PLUS_135);
+            }
+
+        }
+        else
+        {
+            if(mSymbolError.inphase() > 0.0f)
+            {
+                mSymbolDecision = Dibit.D10_MINUS_1;
+                mTimingErrorPolarity = (preceding.quadrature() > current.quadrature() ? 1.0f : -1.0f);
+                mSymbolError.multiply(ROTATE_FROM_MINUS_45);
+            }
+            else
+            {
+                mSymbolDecision = Dibit.D11_MINUS_3;
+                mTimingErrorPolarity = (preceding.quadrature() < current.quadrature() ? 1.0f : -1.0f);
+                mSymbolError.multiply(ROTATE_FROM_MINUS_135);
+            }
+        }
+
+        //Since we've rotated the error symbol back to 0 radians, the quadrature value closely approximates the
+        //arctan of the error angle relative to 0 radians and this provides our error value
+        mPhaseError = -mSymbolError.quadrature();
+
+        //Timing error is the same as phase error with the sign corrected according to the vector's angular rotation
+        mTimingError = mSymbolError.quadrature() * mTimingErrorPolarity;
+    }
+
+    /**
+     * Phase error of the symbol relative to the nearest reference symbol.
+     *
+     * @return phase error in radians of distance from the reference symbol.
+     */
+    @Override
+    public float getPhaseError()
+    {
+        return mPhaseError;
+    }
+
+    /**
+     * Timing error of the symbol relative to the nearest reference symbol.
+     *
+     * @return timing error in radians of angular distance from the reference symbol recognizing that the symbol
+     * originates at zero radians and rotates toward the intended reference symbol, therefore the error value indicates
+     * if the symbol was sampled early (-) or late (+) relative to the reference symbol.
+     */
+    @Override
+    public float getTimingError()
+    {
+        return mTimingError;
+    }
+
+    /**
+     * Reference symbol that is closest to the transmitted/sampled symbol.
+     */
+    @Override
+    public Dibit getSymbolDecision()
+    {
+        return mSymbolDecision;
+    }
+}

src/main/java/io/github/dsheirer/dsp/psk/GardnerDetector.java

@@ -0,0 +1,82 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.sample.complex.Complex;
+
+public class GardnerDetector
+{
+    private float mErrorInphase;
+    private float mErrorQuadrature;
+    private float mError;
+
+    /**
+     * Gardner detector for recovering symbol timing error.
+     */
+    public GardnerDetector()
+    {
+    }
+
+
+    /**
+     * Calculates the symbol timing error by evaluating the previous, middle and current symbol instants.
+     *
+     * @param previous symbol
+     * @param middle symbol (ie midway between the previous and current)
+     * @param current symbol
+     * @return symbol timing error
+     */
+    public float getError(Complex previous, Complex middle, Complex current)
+    {
+        mErrorInphase = (Math.abs(previous.inphase()) - Math.abs(current.inphase())) * Math.abs(middle.inphase());
+        mErrorQuadrature = (Math.abs(previous.quadrature()) - Math.abs(current.quadrature())) * Math.abs(middle.quadrature());
+        mError = normalize(mErrorInphase + mErrorQuadrature, 1.0f);
+
+        return mError;
+    }
+
+    /**
+     * Constrains timing error to +/- the maximum value and corrects any floating point invalid numbers
+     */
+    public static float normalize(float error, float maximum)
+    {
+        if(Float.isNaN(error))
+        {
+            return 0.0f;
+        }
+        else
+        {
+            return clip(error, maximum);
+        }
+    }
+
+    /**
+     * Constrains value to the range of ( -maximum <> maximum )
+     */
+    public static float clip(float value, float maximum)
+    {
+        if(value > maximum)
+        {
+            return maximum;
+        }
+        else if(value < -maximum)
+        {
+            return -maximum;
+        }
+
+        return value;
+    }
+}

src/main/java/io/github/dsheirer/dsp/psk/IDQPSKSymbolEvaluator.java

@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.dsp.symbol.Dibit;
+import io.github.dsheirer.sample.complex.Complex;
+
+
+public interface IDQPSKSymbolEvaluator
+{
+    /**
+     * Sets the sampled symbol to be evaluated.  Note: the symbol's gain value MUST be normalized to the unit circle.
+     *
+     * @param preceding symbol used to detect (counter-)clock-wise rotation
+     * @param symbol currently being sampled
+     */
+    void setSymbol(Complex preceding, Complex symbol);
+
+    /**
+     * Phase error of the symbol relative to the closest reference symbol
+     * @return angular phase error in radians
+     */
+    float getPhaseError();
+
+    /**
+     * Timing error of the symbol relative to the closest reference symbol
+     * @return angular timing error in radians where a positive value indicates early sampling and sample timing needs
+     * to be increased and a negative value indicates late sampling where sample timing needs to be decreased.
+     */
+    float getTimingError();
+
+    /**
+     * Dibit decision indicating the reference symbol location closest to the symbol.
+     * @return symbol decision
+     */
+    Dibit getSymbolDecision();
+}

src/main/java/io/github/dsheirer/dsp/psk/IQPSKSymbolDecoder.java

@@ -0,0 +1,29 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.dsp.symbol.Dibit;
+import io.github.dsheirer.sample.complex.Complex;
+
+public interface IQPSKSymbolDecoder
+{
+    /**
+     * Decodes the symbol and converts it into a Dibit
+     * @param symbol to decode
+     * @return decoded dibit
+     */
+    Dibit decode(Complex symbol);
+}

src/main/java/io/github/dsheirer/dsp/psk/ISymbolPhaseErrorCalculator.java

@@ -0,0 +1,28 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.sample.complex.Complex;
+
+public interface ISymbolPhaseErrorCalculator
+{
+    /**
+     * Calculates the phase error of the symbol relative to an alignment for the constellation
+     * @param symbol to calculate error
+     * @return error value
+     */
+    float getPhaseError(Complex symbol);
+}

src/main/java/io/github/dsheirer/dsp/psk/InterpolatingSampleBuffer.java

@@ -0,0 +1,167 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.dsp.filter.interpolator.RealInterpolator;
+import io.github.dsheirer.sample.complex.Complex;
+
+public class InterpolatingSampleBuffer
+{
+    private static final float MAXIMUM_DEVIATION_SAMPLES_PER_SYMBOL = 0.02f; // +/- 2% deviation
+
+    private Complex mPrecedingSample = new Complex(0,0);
+    private Complex mCurrentSample = new Complex(0,0);
+
+    private float[] mDelayLineInphase;
+    private float[] mDelayLineQuadrature;
+    private int mDelayLinePointer = 0;
+    private int mTwiceSamplesPerSymbol;
+
+    private float mSamplingPoint;
+    private float mSampleCounterGain = 1.0f;
+    private float mDetectedSamplesPerSymbol;
+    private float mDetectedSamplesPerSymbolGain = 0.1f * mSampleCounterGain * mSampleCounterGain;
+    private float mMaximumSamplesPerSymbol;
+    private float mMinimumSamplesPerSymbol;
+
+    private RealInterpolator mInterpolator = new RealInterpolator(1.0f);
+
+    /**
+     * Buffer to store complex sample data and produce interpolated samples.
+     * @param samplesPerSymbol
+     */
+    public InterpolatingSampleBuffer(float samplesPerSymbol)
+    {
+        mSamplingPoint = samplesPerSymbol;
+        mDetectedSamplesPerSymbol = samplesPerSymbol;
+        mMaximumSamplesPerSymbol = samplesPerSymbol * (1.0f + MAXIMUM_DEVIATION_SAMPLES_PER_SYMBOL);
+        mMinimumSamplesPerSymbol = samplesPerSymbol * (1.0f - MAXIMUM_DEVIATION_SAMPLES_PER_SYMBOL);
+        mTwiceSamplesPerSymbol = (int)Math.floor(2.0 * samplesPerSymbol);
+        mDelayLineInphase = new float[2 * mTwiceSamplesPerSymbol];
+        mDelayLineQuadrature = new float[2 * mTwiceSamplesPerSymbol];
+    }
+
+    /**
+     * Stores the sample in the buffer and updates pointers.
+     * @param sample
+     */
+    public void receive(Complex sample)
+    {
+        mSamplingPoint--;
+
+        //Fill up the delay line to use with the interpolator
+        mDelayLineInphase[mDelayLinePointer] = sample.inphase();
+        mDelayLineInphase[mDelayLinePointer + mTwiceSamplesPerSymbol] = sample.inphase();
+        mDelayLineQuadrature[mDelayLinePointer] = sample.quadrature();
+        mDelayLineQuadrature[mDelayLinePointer + mTwiceSamplesPerSymbol] = sample.quadrature();
+
+        //Increment pointer and keep pointer in bounds
+        mDelayLinePointer++;
+        mDelayLinePointer = mDelayLinePointer % mTwiceSamplesPerSymbol;
+    }
+
+    /**
+     * Updates the internal sample counter with additional samples to add to the symbol sample counter.
+     * @param samplesToAdd to the sample counter
+     */
+    public void increaseSampleCounter(float samplesToAdd)
+    {
+        mSamplingPoint += samplesToAdd;
+    }
+
+    /**
+     * Adjusts samples per symbol and symbol timing counters and increments the sample counter to collect another
+     * symbol.
+     *
+     * @param symbolTimingError from a symbol timing error detector
+     */
+    public void resetAndAdjust(float symbolTimingError)
+    {
+        //Adjust detected samples per symbol based on timing error
+        mDetectedSamplesPerSymbol = mDetectedSamplesPerSymbol + (symbolTimingError * mDetectedSamplesPerSymbolGain);
+
+        //Constrain detected samples per symbol to min/max values
+        if(mDetectedSamplesPerSymbol > mMaximumSamplesPerSymbol)
+        {
+            mDetectedSamplesPerSymbol = mMaximumSamplesPerSymbol;
+        }
+
+        if(mDetectedSamplesPerSymbol < mMinimumSamplesPerSymbol)
+        {
+            mDetectedSamplesPerSymbol = mMinimumSamplesPerSymbol;
+        }
+
+        //Add another symbol's worth of samples to the counter and adjust timing based on gardner error
+        increaseSampleCounter((mDetectedSamplesPerSymbol + (symbolTimingError * mSampleCounterGain)));
+    }
+
+    /**
+     * Current value of the detected samples per symbol
+     */
+    public float getSamplingPoint()
+    {
+        return mSamplingPoint;
+    }
+
+    /**
+     * Indicates if this buffer has accumulated a enough samples to represent a full symbol
+     */
+    public boolean hasSymbol()
+    {
+        return mSamplingPoint < 1.0f;
+    }
+
+    /**
+     * Un-interpolated sample that precedes the current interpolated sampling point.  The current sampling point falls
+     * somewhere between sample index 3 and index 4, therefore the preceding sample is located at index 3.
+     */
+    public Complex getPrecedingSample()
+    {
+        mPrecedingSample.setValues(mDelayLineInphase[mDelayLinePointer + 4], mDelayLineQuadrature[mDelayLinePointer + 3]);
+        return mPrecedingSample;
+    }
+
+    /**
+     * Interpolated middle sample for the symbol.  Note: this method should only be invoked after testing for a
+     * complete symbol with the hasSymbol() method.
+     */
+    public Complex getCurrentSample()
+    {
+        /* Calculate interpolated current sample */
+        mCurrentSample.setValues(getInphase(mSamplingPoint), getQuadrature(mSamplingPoint));
+        return mCurrentSample;
+    }
+
+    /**
+     * Returns the interpolated inphase value for the specified offset
+     * @param interpolation into the buffer to calculate the interpolated sample
+     * @return inphase value of the interpolated sample
+     */
+    public float getInphase(float interpolation)
+    {
+        return mInterpolator.filter(mDelayLineInphase, mDelayLinePointer + 1, interpolation);
+    }
+
+    /**
+     * Returns the interpolated quadrature value for the specified offset
+     * @param interpolation into the buffer to calculate the interpolated sample
+     * @return quadrature value of the interpolated sample
+     */
+    public float getQuadrature(float interpolation)
+    {
+        return mInterpolator.filter(mDelayLineQuadrature, mDelayLinePointer + 1, interpolation);
+    }
+}

src/main/java/io/github/dsheirer/dsp/psk/InterpolatingSampleBufferInstrumented.java

@@ -0,0 +1,48 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.sample.complex.Complex;
+
+public class InterpolatingSampleBufferInstrumented extends InterpolatingSampleBuffer
+{
+    private SymbolDecisionData mSymbolDecisionData;
+
+    public InterpolatingSampleBufferInstrumented(float samplesPerSymbol)
+    {
+        super(samplesPerSymbol);
+
+        mSymbolDecisionData = new SymbolDecisionData((int)samplesPerSymbol);
+    }
+
+    public void receive(Complex sample)
+    {
+        super.receive(sample);
+        mSymbolDecisionData.receive(sample);
+    }
+
+    /**
+     * Contents of the interpolating buffer and the current buffer index and symbol decision offset.  This data can
+     * be used to support an external eye-diagram chart.
+     * @return symbol decision data.
+     */
+    public SymbolDecisionData getSymbolDecisionData()
+    {
+        mSymbolDecisionData.setSamplingPoint(getSamplingPoint());
+        return mSymbolDecisionData;
+    }
+
+}

src/main/java/io/github/dsheirer/dsp/psk/LSMConstellationDecoder.java

@@ -0,0 +1,28 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.dsp.symbol.Dibit;
+import io.github.dsheirer.sample.complex.Complex;
+
+public class LSMConstellationDecoder implements IQPSKSymbolDecoder
+{
+    @Override
+    public Dibit decode(Complex symbol)
+    {
+        return null;
+    }
+}

src/main/java/io/github/dsheirer/dsp/psk/LSMDemodulator.java

@@ -2,7 +2,7 @@ package io.github.dsheirer.dsp.psk;
 
 /*******************************************************************************
  *     SDR Trunk 
- *     Copyright (C) 2014, 2015 Dennis Sheirer
+ *     Copyright (C) 2014 - 2018 Dennis Sheirer
  *
  * 	   Gardner detector, Costas loop and Interpolator derived from:
  *
@@ -32,6 +32,7 @@ package io.github.dsheirer.dsp.psk;
 
 import io.github.dsheirer.buffer.FloatAveragingBuffer;
 import io.github.dsheirer.dsp.filter.interpolator.RealInterpolator;
+import io.github.dsheirer.dsp.psk.pll.IPhaseLockedLoop;
 import io.github.dsheirer.dsp.symbol.Dibit;
 import io.github.dsheirer.instrument.Instrumentable;
 import io.github.dsheirer.instrument.tap.Tap;
@@ -57,125 +58,130 @@ import java.util.List;
  */
 public class LSMDemodulator implements Instrumentable, ComplexSampleListener
 {
-	private List<TapGroup> mAvailableTaps;
+    private List<TapGroup> mAvailableTaps;
 
-	/* 45 degree rotation angle */
+    /* 45 degree rotation angle */
-	public static final float THETA = (float)( Math.PI / 4.0d ); 
+    public static final float THETA = (float)(Math.PI / 4.0d);
 
-	/* 45 degree point */
+    /* 45 degree point */
-	public static final Complex POINT_45_DEGREES = 
+    public static final Complex POINT_45_DEGREES = new Complex((float)Math.sin(THETA), (float)Math.cos(THETA));
-		new Complex( (float)Math.sin( THETA ), (float)Math.cos( THETA ) );
 
-	private Listener<Complex> mSymbolListener;
+    private Listener<Complex> mSymbolListener;
 
-	private GardnerSymbolTiming mGardnerDetector = new GardnerSymbolTiming();
+    private GardnerSymbolTiming mGardnerDetector = new GardnerSymbolTiming();
 
-	private CostasLoop mCostasLoop = new CostasLoop();
+    private CostasLoop mCostasLoop = new CostasLoop();
+    private QPSKSymbolDecoder mQPSKSymbolDecoder = new QPSKSymbolDecoder();
 
-	private IFrequencyChangeListener mFrequencyChangeListener;
+    private IFrequencyChangeListener mFrequencyChangeListener;
 
-	private EyeDiagramDataTap mEyeDiagramDataTap;
+    private EyeDiagramDataTap mEyeDiagramDataTap;
 
-	public LSMDemodulator()
+    public LSMDemodulator()
-	{
+    {
-	}
+    }
 
-	public void dispose()
+    public CostasLoop getCostasLoop()
-	{
+    {
-		mSymbolListener = null;
+        return mCostasLoop;
-		mFrequencyChangeListener = null;
+    }
-	}
 
-	public void setSymbolListener( Listener<Complex> listener )
+    public void dispose()
-	{
+    {
-		mSymbolListener = listener;
+        mSymbolListener = null;
-	}
+        mFrequencyChangeListener = null;
+    }
 
-	public void removeSymbolListener()
+    public void setSymbolListener(Listener<Complex> listener)
-	{
+    {
-		mSymbolListener = null;
+        mSymbolListener = listener;
-	}
+    }
 
-	@Override
+    public void removeSymbolListener()
-	public void receive( float inphase, float quadrature )
+    {
-	{
+        mSymbolListener = null;
-		mGardnerDetector.receive( inphase, quadrature );
+    }
-	}
 
-	/**
+    @Override
-	 * Applies a phase correction value to the costas loop to correct when a
+    public void receive(float inphase, float quadrature)
-	 * phase lock error is detected in the binary output stream.
+    {
-	 * 
+        mGardnerDetector.receive(inphase, quadrature);
-	 * @param correction - value in radians
+    }
-	 */
-	public void correctPhaseError( double correction )
-	{
-		mCostasLoop.correctPhaseError( correction );
-	}
 
-	/**
+    /**
-	 * Constrains value to the range of ( -maximum <> maximum )
+     * Applies a phase correction value to the costas loop to correct when a
-	 */
+     * phase lock error is detected in the binary output stream.
-	public static float clip( float value, float maximum )
+     *
-	{
+     * @param correction - value in radians
-		if( value > maximum )
+     */
-		{
+    public void correctPhaseError(double correction)
-			return maximum;
+    {
-		}
+        mCostasLoop.correctPhaseError(correction);
-		else if( value < -maximum )
+    }
-		{
-			return -maximum;
-		}
 
-		return value;
+    /**
-	}
+     * Constrains value to the range of ( -maximum <> maximum )
+     */
+    public static float clip(float value, float maximum)
+    {
+        if(value > maximum)
+        {
+            return maximum;
+        }
+        else if(value < -maximum)
+        {
+            return -maximum;
+        }
 
-	/**
+        return value;
-	 * Constrains timing error to +/- the maximum value and corrects any
+    }
-	 * floating point invalid numbers
-	 */
-	private float normalize( float error, float maximum )
-	{
-		if( Float.isNaN( error ) )
-		{
-			return 0.0f;
-		}
-		else
-		{
-			return clip( error, maximum );
-		}
-	}
 
-	public void addListener( IFrequencyChangeListener listener )
+    /**
-	{
+     * Constrains timing error to +/- the maximum value and corrects any
-		mFrequencyChangeListener = listener;
+     * floating point invalid numbers
-	}
+     */
+    private float normalize(float error, float maximum)
+    {
+        if(Float.isNaN(error))
+        {
+            return 0.0f;
+        }
+        else
+        {
+            return clip(error, maximum);
+        }
+    }
 
-	public void removeListener( IFrequencyChangeListener listener )
+    public void addListener(IFrequencyChangeListener listener)
-	{
+    {
-		mFrequencyChangeListener = null;
+        mFrequencyChangeListener = listener;
-	}
+    }
 
-	/**
+    public void removeListener(IFrequencyChangeListener listener)
-	 * Processes the current loop frequency of the costas loop and broadcasts
+    {
-	 * tuner frequency offset adjustments 10 times a second as needed to keep
+        mFrequencyChangeListener = null;
-	 * the frequency offset below half of the maximum frequency
+    }
-	 */
-	public class FrequencyControl
-	{	
-		/* Set the trigger threshold at half of the maximum costas loop control
-		 * frequency */
-		private static final float CORRECTION_THRESHOLD_FREQUENCY = 
-			( 2.0f * (float)Math.PI * 600.0f ) / 48000.0f;
 
-		private FloatAveragingBuffer mBuffer = new FloatAveragingBuffer( 40 );
+    /**
+     * Processes the current loop frequency of the costas loop and broadcasts
+     * tuner frequency offset adjustments 10 times a second as needed to keep
+     * the frequency offset below half of the maximum frequency
+     */
+    public class FrequencyControl
+    {
+        /* Set the trigger threshold at half of the maximum costas loop control
+         * frequency */
+        private static final float CORRECTION_THRESHOLD_FREQUENCY =
+            (2.0f * (float)Math.PI * 600.0f) / 48000.0f;
 
-		private long mFrequencyError = 0;
+        private FloatAveragingBuffer mBuffer = new FloatAveragingBuffer(40);
 
-		private int mCounter = 0;
+        private long mFrequencyError = 0;
 
-		public void receive( float frequency )
+        private int mCounter = 0;
-		{
+
+        public void receive(float frequency)
+        {
 //			mCounter++;
 //			
 //			if( mCounter >= 480 )
@@ -212,377 +218,402 @@ public class LSMDemodulator implements Instrumentable, ComplexSampleListener
 //			{
 //				mBuffer.get( frequency );
 //			}
-		}
+        }
-	}
+    }
 
-	/**
+    /**
-	 * Gardner symbol timing detector
+     * Gardner symbol timing detector
-	 */
+     */
-	public class GardnerSymbolTiming implements ComplexSampleListener
+    public class GardnerSymbolTiming implements ComplexSampleListener
-	{
+    {
-		public static final int HALF_SAMPLES_PER_SYMBOL = 5;
+        public static final int HALF_SAMPLES_PER_SYMBOL = 5;
-		public static final int SAMPLES_PER_SYMBOL = 10;
+        public static final int SAMPLES_PER_SYMBOL = 10;
-		public static final int TWICE_SAMPLES_PER_SYMBOL = 20;
+        public static final int TWICE_SAMPLES_PER_SYMBOL = 20;
 
-		private float[] mDelayLineInphase = new float[ 2 * TWICE_SAMPLES_PER_SYMBOL ];
+        private float[] mDelayLineInphase = new float[2 * TWICE_SAMPLES_PER_SYMBOL];
-		private float[] mDelayLineQuadrature = new float[ 2 * TWICE_SAMPLES_PER_SYMBOL ];
+        private float[] mDelayLineQuadrature = new float[2 * TWICE_SAMPLES_PER_SYMBOL];
 
-		private int mDelayLinePointer = 0;
+        private int mDelayLinePointer = 0;
 
-		/* Sampling point */
+        /* Sampling point */
-		private float mMu = 10.0f;
+        private float mMu = 10.0f;
-		private float mGainMu = 0.05f;
+        private float mGainMu = 0.05f;
 
-		/* Samples per symbol */
+        /* Samples per symbol */
-		private float mOmega = 10.0f;
+        private float mOmega = 10.0f;
-		private float mGainOmega = 0.1f * mGainMu * mGainMu;
+        private float mGainOmega = 0.1f * mGainMu * mGainMu;
-		private float mOmegaRel = 0.005f;
+        private float mOmegaRel = 0.005f;
-		private float mOmegaMid = 10.0f;
+        private float mOmegaMid = 10.0f;
 
-		private RealInterpolator mInterpolator = new RealInterpolator( 1.0f );
+        private RealInterpolator mInterpolator = new RealInterpolator(1.0f);
 
-		private Complex mPreviousSample = new Complex( 0, 0 );
+        private Complex mPreviousSample = new Complex(0, 0);
-		private Complex mPreviousMiddleSample = new Complex( 0, 0 );
+        private Complex mPreviousMiddleSample = new Complex(0, 0);
-		private Complex mPreviousSymbol = new Complex( 0, 0 );
+        private Complex mPreviousSymbol = new Complex(0, 0);
 
-		/**
+        /**
-		 * Provides symbol sampling timing control
+         * Provides symbol sampling timing control
-		 */
+         */
-		public GardnerSymbolTiming()
+        public GardnerSymbolTiming()
-		{
+        {
-		}
+        }
 
-		@Override
+        @Override
-		public void receive( float inphase, float quadrature )
+        public void receive(float inphase, float quadrature)
-		{
+        {
-			/* Count down samples per symbol until we calculate the symbol */
+            /* Count down samples per symbol until we calculate the symbol */
-			mMu--;
+            mMu--;
 
-			mCostasLoop.increment();
+            mCostasLoop.increment();
 
-			/* Mix incoming sample with costas loop to remove any rotation
+            /* Mix incoming sample with costas loop to remove any rotation
-			 * that is present from a mis-tuned carrier frequency */
+             * that is present from a mis-tuned carrier frequency */
 
-			Complex costas = mCostasLoop.getCurrentVector();
+            Complex costas = mCostasLoop.getCurrentVector();
 
-			float derotatedInphase = Complex.multiplyInphase( inphase, quadrature, costas.inphase(), costas.quadrature() );
+            float derotatedInphase = Complex.multiplyInphase(inphase, quadrature, costas.inphase(), costas.quadrature());
-			float derotatedQuadrature = Complex.multiplyQuadrature( inphase, quadrature, costas.inphase(), costas.quadrature() );
+            float derotatedQuadrature = Complex.multiplyQuadrature(inphase, quadrature, costas.inphase(), costas.quadrature());
 
-			/* Fill up the delay line to use with the interpolator */
+            /* Fill up the delay line to use with the interpolator */
-			mDelayLineInphase[ mDelayLinePointer ] = derotatedInphase;
+            mDelayLineInphase[mDelayLinePointer] = derotatedInphase;
-			mDelayLineInphase[ mDelayLinePointer + TWICE_SAMPLES_PER_SYMBOL ] = derotatedInphase;
+            mDelayLineInphase[mDelayLinePointer + TWICE_SAMPLES_PER_SYMBOL] = derotatedInphase;
 
-			mDelayLineQuadrature[ mDelayLinePointer ] = derotatedQuadrature;
+            mDelayLineQuadrature[mDelayLinePointer] = derotatedQuadrature;
-			mDelayLineQuadrature[ mDelayLinePointer + TWICE_SAMPLES_PER_SYMBOL ] = derotatedQuadrature;
+            mDelayLineQuadrature[mDelayLinePointer + TWICE_SAMPLES_PER_SYMBOL] = derotatedQuadrature;
 
-			/* Increment pointer and keep pointer in bounds */
+            /* Increment pointer and keep pointer in bounds */
-			mDelayLinePointer = ( mDelayLinePointer + 1 ) % TWICE_SAMPLES_PER_SYMBOL;
+            mDelayLinePointer = (mDelayLinePointer + 1) % TWICE_SAMPLES_PER_SYMBOL;
 
-			/* Calculate the symbol once we've stored enough samples */
+            /* Calculate the symbol once we've stored enough samples */
-			if( mMu <= 1.0f )
+            if(mMu <= 1.0f)
-			{
+            {
-				float half_omega = mOmega / 2.0f;
+                float half_omega = mOmega / 2.0f;
-				int half_sps = (int)Math.floor( half_omega );
+                int half_sps = (int)Math.floor(half_omega);
-				float half_mu = mMu + half_omega - (float)half_sps;
+                float half_mu = mMu + half_omega - (float)half_sps;
 
-				if( half_mu > 1.0 )
+                if(half_mu > 1.0)
-				{
+                {
-					half_mu -= 1.0;
+                    half_mu -= 1.0;
-					half_sps += 1;
+                    half_sps += 1;
-				}
+                }
 
-				/* Calculate interpolated middle sample and current sample */
+                /* Calculate interpolated middle sample and current sample */
-				float middleSampleInphase = mInterpolator.filter( 
+                float middleSampleInphase = mInterpolator.filter(
-						mDelayLineInphase, mDelayLinePointer, mMu );
+                    mDelayLineInphase, mDelayLinePointer, mMu);
-				float middleSampleQuadrature = mInterpolator.filter( 
+                float middleSampleQuadrature = mInterpolator.filter(
-						mDelayLineQuadrature, mDelayLinePointer, mMu );
+                    mDelayLineQuadrature, mDelayLinePointer, mMu);
 
-				int index = mDelayLinePointer + half_sps;
+                int index = mDelayLinePointer + half_sps;
 
-				float currentSampleInphase = mInterpolator.filter( 
+                float currentSampleInphase = mInterpolator.filter(
-						mDelayLineInphase, index, half_mu );
+                    mDelayLineInphase, index, half_mu);
-				float currentSampleQuadrature = mInterpolator.filter( 
+                float currentSampleQuadrature = mInterpolator.filter(
-						mDelayLineQuadrature, index, half_mu );
+                    mDelayLineQuadrature, index, half_mu);
 
-				/* Multiply current sample and conjugate (negated quadrature) of
+                /* Multiply current sample and conjugate (negated quadrature) of
-				 * previous sample to get symbols to use for gardner error feedback */
+                 * previous sample to get symbols to use for gardner error feedback */
-				Complex middleSymbol = Complex.multiply( middleSampleInphase, 
+                Complex middleSymbol = Complex.multiply(middleSampleInphase,
-						middleSampleQuadrature, mPreviousMiddleSample.conjugate() );
+                    middleSampleQuadrature, mPreviousMiddleSample.conjugate());
-				Complex currentSymbol = Complex.multiply( currentSampleInphase, 
+                Complex currentSymbol = Complex.multiply(currentSampleInphase,
-						currentSampleQuadrature, mPreviousSample.conjugate() );
+                    currentSampleQuadrature, mPreviousSample.conjugate());
 
-				/* Set gain to unity */
+                /* Set gain to unity */
-				middleSymbol.normalize();
+                middleSymbol.normalize();
-				currentSymbol.normalize();
+                currentSymbol.normalize();
 
-				/* Gardner timing error calculations */
+                /* Gardner timing error calculations */
-				float errorInphase = ( mPreviousSymbol.inphase() - 
+                float errorInphase = (mPreviousSymbol.inphase() -
-						currentSymbol.inphase() ) * middleSymbol.inphase();
+                    currentSymbol.inphase()) * middleSymbol.inphase();
 
-				float errorQuadrature = ( mPreviousSymbol.quadrature() - 
+                float errorQuadrature = (mPreviousSymbol.quadrature() -
-						currentSymbol.quadrature() ) * middleSymbol.quadrature();
+                    currentSymbol.quadrature()) * middleSymbol.quadrature();
 
-				float gardnerError = normalize( errorInphase + errorQuadrature, 1.0f );
+                float gardnerError = normalize(errorInphase + errorQuadrature, 1.0f);
 
-				if( mEyeDiagramDataTap != null )
+                if(mEyeDiagramDataTap != null)
-				{
+                {
-					mEyeDiagramDataTap.receive( 
+                    mEyeDiagramDataTap.receive(
-						new EyeDiagramData( 
+                        new EyeDiagramData(
-								Arrays.copyOfRange( mDelayLineInphase, 0, 20 ), 
+                            Arrays.copyOfRange(mDelayLineInphase, 0, 20),
-								Arrays.copyOfRange( mDelayLineQuadrature, 0, 20 ), 
+                            Arrays.copyOfRange(mDelayLineQuadrature, 0, 20),
-							mMu, (float)half_sps + half_mu, gardnerError ) );
+                            mMu, (float)half_sps + half_mu, gardnerError));
-				}
+                }
 
-				/* mOmega is samples per symbol and is constrained to floating
+                /* mOmega is samples per symbol and is constrained to floating
-				 * between +/- .005 of the nominal 10.0 samples per symbol */
+                 * between +/- .005 of the nominal 10.0 samples per symbol */
-				mOmega = mOmega + mGainOmega * gardnerError;
+                mOmega = mOmega + mGainOmega * gardnerError;
-				mOmega = mOmegaMid + clip( mOmega - mOmegaMid, mOmegaRel );
+                mOmega = mOmegaMid + clip(mOmega - mOmegaMid, mOmegaRel);
 
-				/* Adjust sample timing based on error of current sample */
+                /* Adjust sample timing based on error of current sample */
-				mMu += mOmega + ( mGainMu * gardnerError );
+                mMu += mOmega + (mGainMu * gardnerError);
 
-				/* Store current samples/symbols to use for the next period */
+                /* Store current samples/symbols to use for the next period */
-				mPreviousSample.setValues( currentSampleInphase, currentSampleQuadrature );
+                mPreviousSample.setValues(currentSampleInphase, currentSampleQuadrature);
-				mPreviousMiddleSample.setValues( middleSampleInphase, middleSampleQuadrature );
+                mPreviousMiddleSample.setValues(middleSampleInphase, middleSampleQuadrature);
-				mPreviousSymbol = currentSymbol;
+                mPreviousSymbol = currentSymbol;
 
-				/* Update costas loop using phase error present in current 
+                /* Update costas loop using phase error present in current
-				 * symbol.  The symbol is rotated from star orientation to polar
+                 * symbol.  The symbol is rotated from star orientation to polar
-				 * orientation to simplify error calculation */
+                 * orientation to simplify error calculation */
-				mCostasLoop.receive( currentSymbol );
+                mCostasLoop.receive(currentSymbol);
 //				mCostasLoop.receive( 
 //						ComplexSample.multiply( currentSymbol, POINT_45_DEGREES ) );
 
-				/* Dispatch the differentiated symbol to the registered listener */
+                /* Dispatch the differentiated symbol to the registered listener */
-				if( mSymbolListener != null )
+                if(mSymbolListener != null)
-				{
+                {
-					mSymbolListener.receive( currentSymbol );
+                    mSymbolListener.receive(currentSymbol);
-				}
+                }
-			}
+            }
-		}
+        }
-	}
+    }
 
-	/**
+    /**
-	 * Costas Loop - phase locked loop synchronized to the frequency offset of
+     * Costas Loop - phase locked loop synchronized to the frequency offset of
-	 * the incoming signal to enable the signal to be mixed down to zero offset
+     * the incoming signal to enable the signal to be mixed down to zero offset
-	 * for proper synchronization.  The mFrequency value indicates the detected
+     * for proper synchronization.  The mFrequency value indicates the detected
-	 * frequency offset.  We attempt to keep that value close to zero by issuing
+     * frequency offset.  We attempt to keep that value close to zero by issuing
-	 * frequency adjustments to the tuner channel source.
+     * frequency adjustments to the tuner channel source.
-	 * 
+     *
-	 * Most of the costas loop code was ported from gnuradio/control_loop and 
+     * Most of the costas loop code was ported from gnuradio/control_loop and
-	 * gnuradio/mpsk_receiver_cc using initialization values from KA1RBI's 
+     * gnuradio/mpsk_receiver_cc using initialization values from KA1RBI's
-	 * OP25/cqpsk.py
+     * OP25/cqpsk.py
-	 */
+     */
-	public class CostasLoop implements Listener<Complex>
+    public class CostasLoop implements Listener<Complex>, IPhaseLockedLoop
-	{
+    {
-		public static final double TWO_PI = 2.0 * Math.PI;
+        public static final double TWO_PI = 2.0 * Math.PI;
 
-		private static final float MAXIMUM_FREQUENCY = 
+        private static final float MAXIMUM_FREQUENCY =
-				( 2400.0f * (float)TWO_PI ) / 48000.0f;
+            (2400.0f * (float)TWO_PI) / 48000.0f;
 
-		/* http://www.trondeau.com/blog/2011/8/13/control-loop-gain-values.html */
+        /* http://www.trondeau.com/blog/2011/8/13/control-loop-gain-values.html */
-		private float mDamping = (float)Math.sqrt( 2.0 ) / 2.0f;
+        private float mDamping = (float)Math.sqrt(2.0) / 2.0f;
 
-		/* Use denominator between 100 (most) and 400 (least) to adjust costas
+        /* Use denominator between 100 (most) and 400 (least) to adjust costas
-		 * loop control level */
+         * loop control level */
-		private float mLoopBandwidth = (float)( TWO_PI / 400.0d );
+        private float mLoopBandwidth = (float)(TWO_PI / 400.0d);
 
-		private float mAlphaGain = ( 4.0f * mDamping * mLoopBandwidth ) / 
+        private float mAlphaGain = (4.0f * mDamping * mLoopBandwidth) /
-						  ( 1.0f + ( 2.0f * mDamping * mLoopBandwidth ) + 
+            (1.0f + (2.0f * mDamping * mLoopBandwidth) +
-								   ( mLoopBandwidth * mLoopBandwidth ) );
+                (mLoopBandwidth * mLoopBandwidth));
 
-		private float mBetaGain = ( 4.0f * mLoopBandwidth * mLoopBandwidth ) / 
+        private float mBetaGain = (4.0f * mLoopBandwidth * mLoopBandwidth) /
-							   ( 1.0f + ( 2.0f * mDamping * mLoopBandwidth ) + 
+            (1.0f + (2.0f * mDamping * mLoopBandwidth) +
-								   ( mLoopBandwidth * mLoopBandwidth ) );
+                (mLoopBandwidth * mLoopBandwidth));
 
-		private float mLoopPhase = 0.0f;
+        private float mLoopPhase = 0.0f;
 
-		private float mLoopFrequency = 0.0f;
+        private float mLoopFrequency = 0.0f;
 
-		private FrequencyControl mFrequencyControl = new FrequencyControl();
+        private FrequencyControl mFrequencyControl = new FrequencyControl();
 
-		public CostasLoop()
+        public CostasLoop()
-		{
+        {
-		}
+        }
 
-		/**
+        /**
-		 * Applies a phase correction value to the current phasor.  Use this 
+         * Applies a phase correction value to the current phasor.  Use this
-		 * method to apply correction when a +/- 90, or 180 degree phase error
+         * method to apply correction when a +/- 90, or 180 degree phase error
-		 * is detected in the binary output stream.
+         * is detected in the binary output stream.
-		 * 
+         *
-		 * If the supplied correction value places the loop frequency outside
+         * If the supplied correction value places the loop frequency outside
-		 * of the max frequency, then the frequency will be corrected 360
+         * of the max frequency, then the frequency will be corrected 360
-		 * degrees in the opposite direction to maintain within the max
+         * degrees in the opposite direction to maintain within the max
-		 * frequency bounds.
+         * frequency bounds.
-		 * 
+         *
-		 * @param correction - correction value in radians
+         * @param correction - correction value in radians
-		 */
+         */
-		public void correctPhaseError( double correction )
+        public void correctPhaseError(double correction)
-		{
+        {
-			mLoopFrequency += correction;
+            mLoopFrequency += correction;
 
-			if( mLoopFrequency > MAXIMUM_FREQUENCY )
+            if(mLoopFrequency > MAXIMUM_FREQUENCY)
-			{
+            {
-				mLoopFrequency -= 2.0d * MAXIMUM_FREQUENCY;
+                mLoopFrequency -= 2.0d * MAXIMUM_FREQUENCY;
-			}
+            }
 
-			if( mLoopFrequency < -MAXIMUM_FREQUENCY )
+            if(mLoopFrequency < -MAXIMUM_FREQUENCY)
-			{
+            {
-				mLoopFrequency += 2.0d * MAXIMUM_FREQUENCY;
+                mLoopFrequency += 2.0d * MAXIMUM_FREQUENCY;
-			}
+            }
-		}
+        }
 
-		/**
+        /**
-		 * Increments the phase of the loop
+         * Increments the phase of the loop
-		 */
+         */
-		public void increment()
+        public void increment()
-		{
+        {
-			mLoopPhase += mLoopFrequency;
+            mLoopPhase += mLoopFrequency;
 
-			/* Keep the loop phase in bounds */
+            /* Keep the loop phase in bounds */
-			unwrapPhase();
+            unwrapPhase();
-		}
+        }
 
-		private void unwrapPhase()
+        @Override
-		{
+        public void reset()
-			while( mLoopPhase > TWO_PI )
+        {
-			{
+            mLoopPhase = 0.0f;
-				mLoopPhase -= TWO_PI;
+            mLoopFrequency = 0.0f;
-			}
+        }
 
-			while( mLoopPhase < -TWO_PI )
+        @Override
-			{
+        public void adjust(double error)
-				mLoopPhase += TWO_PI;
+        {
-			}
+            adjust(error);
-		}
+        }
 
-		/**
+        @Override
-		 * Current vector of the loop rotated by THETA degrees.
+        public void correctInversion(double correction)
-		 */
+        {
-		public Complex getCurrentVector()
+            correctPhaseError(correction);
-		{
+        }
+
+        private void unwrapPhase()
+        {
+            while(mLoopPhase > TWO_PI)
+            {
+                mLoopPhase -= TWO_PI;
+            }
+
+            while(mLoopPhase < -TWO_PI)
+            {
+                mLoopPhase += TWO_PI;
+            }
+        }
+
+        /**
+         * Current vector of the loop rotated by THETA degrees.
+         */
+        public Complex getCurrentVector()
+        {
 //			return ComplexSample.fromAngle( mLoopPhase + THETA );
-			return Complex.fromAngle( mLoopPhase );
+            return Complex.fromAngle(mLoopPhase);
-		}
+        }
 
-		@Override
+        @Override
-		public void receive( Complex complex )
+        public Complex incrementAndGetCurrentVector()
-		{
+        {
-			/* Calculate phase error */
+            return null;
-			float phaseError = getPhaseError( complex );
+        }
 
-			Dibit d = QPSKPolarSlicer.decide( complex );
+        @Override
+        public void receive(Complex complex)
+        {
+            /* Calculate phase error */
+            float phaseError = getPhaseError(complex);
+
+            Dibit d = mQPSKSymbolDecoder.decode(complex);
 //			mLog.debug( "Dibit: " + d.name() + " Error: " + phaseError );
 
-			/* Adjust for phase error */
+            /* Adjust for phase error */
-			adjust( phaseError );
+            adjust(phaseError);
-		}
+        }
 
-		/**
+        /**
-		 * Updates the costas loop frequency and phase to adjust for the phase
+         * Updates the costas loop frequency and phase to adjust for the phase
-		 * error value 
+         * error value
-		 * 
+         *
-		 * @param phase_error - (-)= late and (+)= early
+         * @param phase_error - (-)= late and (+)= early
-		 */
+         */
-		private void adjust( float phase_error )
+        private void adjust(float phase_error)
-		{
+        {
-			mLoopFrequency += mBetaGain * phase_error;
+            mLoopFrequency += mBetaGain * phase_error;
-			mLoopPhase += mLoopFrequency + mAlphaGain * phase_error;
+            mLoopPhase += mLoopFrequency + mAlphaGain * phase_error;
 
-			/* Maintain phase between +/- 2 * PI */
+            /* Maintain phase between +/- 2 * PI */
-			unwrapPhase();
+            unwrapPhase();
 
-			/* Limit frequency to +/- maximum loop frequency */
+            /* Limit frequency to +/- maximum loop frequency */
-			limitFrequency();
+            limitFrequency();
-		}
+        }
 
-		/**
+        /**
-		 * Constrains the frequency within the bounds of +/- loop frequency
+         * Constrains the frequency within the bounds of +/- loop frequency
-		 */
+         */
-		private void limitFrequency()
+        private void limitFrequency()
-		{
+        {
-			/* Check for and issue tuner offset correction */
+            /* Check for and issue tuner offset correction */
-			mFrequencyControl.receive( mLoopFrequency );
+            mFrequencyControl.receive(mLoopFrequency);
 
-			if( mLoopFrequency > MAXIMUM_FREQUENCY )
+            if(mLoopFrequency > MAXIMUM_FREQUENCY)
-			{
+            {
-				mLoopFrequency = MAXIMUM_FREQUENCY;
+                mLoopFrequency = MAXIMUM_FREQUENCY;
-			}
+            }
 
-			if( mLoopFrequency < -MAXIMUM_FREQUENCY )
+            if(mLoopFrequency < -MAXIMUM_FREQUENCY)
-			{
+            {
-				mLoopFrequency = -MAXIMUM_FREQUENCY;
+                mLoopFrequency = -MAXIMUM_FREQUENCY;
-			}
+            }
-		}
+        }
 
-		/**
+        /**
-		 * Detects rotational error present when the costas loop is not aligned
+         * Detects rotational error present when the costas loop is not aligned
-		 * with the carrier frequency.  Provides error feedback to adjust 
+         * with the carrier frequency.  Provides error feedback to adjust
-		 * mixer frequency.
+         * mixer frequency.
-		 */
+         */
-		public float getPhaseError( Complex complex )
+        public float getPhaseError(Complex complex)
-		{
+        {
-			  float phase_error = 0;
+            float phase_error = 0;
 
-			  if( Math.abs( complex.inphase() ) > Math.abs( complex.quadrature() ) ) 
+            if(Math.abs(complex.inphase()) > Math.abs(complex.quadrature()))
-			  {
+            {
-				  if( complex.inphase() > 0 )
+                if(complex.inphase() > 0)
-				  {
+                {
-					  phase_error = -complex.quadrature();
+                    phase_error = -complex.quadrature();
-				  }
+                }
-				  else
+                else
-				  {
+                {
-					  phase_error = complex.quadrature();
+                    phase_error = complex.quadrature();
-				  }
+                }
-			  }
+            }
-			  else 
+            else
-			  {
+            {
-				  if( complex.quadrature() > 0 )
+                if(complex.quadrature() > 0)
-				  {
+                {
-					  phase_error = complex.inphase();
+                    phase_error = complex.inphase();
-				  }
+                }
-				  else
+                else
-				  {
+                {
-					  phase_error = -complex.inphase();
+                    phase_error = -complex.inphase();
-				  }
+                }
-			  }
+            }
 
-			  return phase_error;
+            return phase_error;
-		}
+        }
-	}
+    }
 
-	@Override
+    @Override
-	public List<TapGroup> getTapGroups()
+    public List<TapGroup> getTapGroups()
-	{
+    {
-		if( mAvailableTaps == null )
+        if(mAvailableTaps == null)
-		{
+        {
-			mAvailableTaps = new ArrayList<>();
+            mAvailableTaps = new ArrayList<>();
 
-			TapGroup group = new TapGroup( "LSM Demodulator" );
+            TapGroup group = new TapGroup("LSM Demodulator");
 
-			group.add( new EyeDiagramDataTap( "Eye Diagram", 0, 4800 ) );
+            group.add(new EyeDiagramDataTap("Eye Diagram", 0, 4800));
 
-			mAvailableTaps.add( group );
+            mAvailableTaps.add(group);
-		}
+        }
 
-		return mAvailableTaps;
+        return mAvailableTaps;
-	}
+    }
 
-	@Override
+    @Override
-	public void registerTap( Tap tap )
+    public void registerTap(Tap tap)
-	{
+    {
-		if( tap instanceof EyeDiagramDataTap )
+        if(tap instanceof EyeDiagramDataTap)
-		{
+        {
-			mEyeDiagramDataTap = (EyeDiagramDataTap)tap;
+            mEyeDiagramDataTap = (EyeDiagramDataTap)tap;
-		}
+        }
-	}
+    }
 
-	@Override
+    @Override
-	public void unregisterTap( Tap tap )
+    public void unregisterTap(Tap tap)
-	{
+    {
-		if( tap instanceof EyeDiagramDataTap )
+        if(tap instanceof EyeDiagramDataTap)
-		{
+        {
-			mEyeDiagramDataTap = null;
+            mEyeDiagramDataTap = null;
-		}
+        }
-	}
+    }
 }

src/main/java/io/github/dsheirer/dsp/psk/QPSKStarSlicer.java

@@ -1,3 +1,18 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
 
 import io.github.dsheirer.dsp.symbol.Dibit;
@@ -5,54 +20,54 @@ import io.github.dsheirer.sample.Broadcaster;
 import io.github.dsheirer.sample.Listener;
 import io.github.dsheirer.sample.complex.Complex;
 
-public class QPSKStarSlicer implements Listener<Complex>
+public class QPSKStarSlicer implements IQPSKSymbolDecoder, Listener<Complex>
 {
-	private Broadcaster<Dibit> mBroadcaster = new Broadcaster<Dibit>();
+    private Broadcaster<Dibit> mBroadcaster = new Broadcaster<Dibit>();
 
-	/**
+    /**
-	 * Slices a ComplexSample representing a phase shifted symbol according to
+     * Slices a Complex sample representing a phase shifted symbol according to the following constellation pattern:
-	 * the following constellation pattern:
+     *
-	 * 
+     * 00 +3 | 01 +1
-	 *    00 | 01
+     * ------|------
-	 *    ---|---
+     * 10 -1 | 11 -1
-	 *    10 | 11
+     */
-	 */
+    public QPSKStarSlicer()
-	public QPSKStarSlicer()
+    {
-	{
+    }
-	}
 
-	public void dispose()
+    public void dispose()
-	{
+    {
-		mBroadcaster.dispose();
+        mBroadcaster.dispose();
-		mBroadcaster = null;
+        mBroadcaster = null;
-	}
+    }
 
-	public void addListener( Listener<Dibit> listener )
+    public void addListener(Listener<Dibit> listener)
-	{
+    {
-		mBroadcaster.addListener( listener );
+        mBroadcaster.addListener(listener);
-	}
+    }
 
-	public void removeListener( Listener<Dibit> listener )
+    public void removeListener(Listener<Dibit> listener)
-	{
+    {
-		mBroadcaster.removeListener( listener );
+        mBroadcaster.removeListener(listener);
-	}
+    }
 
-	@Override
+    @Override
-	public void receive( Complex sample )
+    public void receive(Complex sample)
-	{
+    {
-		mBroadcaster.broadcast( decide( sample ) );
+        mBroadcaster.broadcast(decode(sample));
-	}
+    }
 
-	public static Dibit decide( Complex sample )
+    @Override
-	{
+    public Dibit decode(Complex sample)
-		if( sample.inphase() > 0 )
+    {
-		{
+        if(sample.inphase() > 0)
-			return sample.quadrature() > 0 ? Dibit.D00_PLUS_1 : Dibit.D10_MINUS_1;
+        {
-		}
+            return sample.quadrature() > 0 ? Dibit.D00_PLUS_1 : Dibit.D10_MINUS_1;
-		else
+        }
-		{
+        else
-			return sample.quadrature() > 0 ? Dibit.D01_PLUS_3 : Dibit.D11_MINUS_3;
+        {
-		}
+            return sample.quadrature() > 0 ? Dibit.D01_PLUS_3 : Dibit.D11_MINUS_3;
-	}
+        }
+    }
 
 }

src/main/java/io/github/dsheirer/dsp/psk/QPSKSymbolDecoder.java

@@ -1,3 +1,18 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
 
 import io.github.dsheirer.dsp.symbol.Dibit;
@@ -5,24 +20,7 @@ import io.github.dsheirer.sample.Broadcaster;
 import io.github.dsheirer.sample.Listener;
 import io.github.dsheirer.sample.complex.Complex;
 
-/*******************************************************************************
+public class QPSKSymbolDecoder implements Listener<Complex>, IQPSKSymbolDecoder
- *     SDR Trunk 
- *     Copyright (C) 2014,2015 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/>
- ******************************************************************************/
-public class QPSKPolarSlicer implements Listener<Complex>
 {
 	private Broadcaster<Dibit> mBroadcaster = new Broadcaster<Dibit>();
 	
@@ -37,7 +35,7 @@ public class QPSKPolarSlicer implements Listener<Complex>
 	 *     /  \
 	 *    / 11 \
 	 */
-	public QPSKPolarSlicer()
+	public QPSKSymbolDecoder()
 	{
 	}
 	
@@ -60,10 +58,10 @@ public class QPSKPolarSlicer implements Listener<Complex>
 	@Override
 	public void receive( Complex complex )
 	{
-		mBroadcaster.broadcast( decide( complex ) );
+		mBroadcaster.broadcast( decode( complex ) );
 	}
 	
-	public static Dibit decide( Complex complex )
+	public Dibit decode(Complex complex )
 	{
 		if( Math.abs( complex.inphase() ) > Math.abs( complex.quadrature() ) )
 		{

src/main/java/io/github/dsheirer/dsp/psk/QPSKSymbolPhaseErrorCalculator.java

@@ -0,0 +1,57 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.sample.complex.Complex;
+
+/**
+ * Calculates the phase error for a QPSK polar-orientation constellation
+ */
+public class QPSKSymbolPhaseErrorCalculator implements ISymbolPhaseErrorCalculator
+{
+    private float mPhaseError;
+
+    @Override
+    public float getPhaseError(Complex symbol)
+    {
+        mPhaseError = 0.0f;
+
+        if(Math.abs(symbol.inphase()) > Math.abs(symbol.quadrature()))
+        {
+            if(symbol.inphase() > 0)
+            {
+                mPhaseError = -symbol.quadrature();
+            }
+            else
+            {
+                mPhaseError = symbol.quadrature();
+            }
+        }
+        else
+        {
+            if(symbol.quadrature() > 0)
+            {
+                mPhaseError = symbol.inphase();
+            }
+            else
+            {
+                mPhaseError = -symbol.inphase();
+            }
+        }
+
+        return mPhaseError;
+    }
+}

src/main/java/io/github/dsheirer/dsp/psk/SymbolDecisionData.java

@@ -0,0 +1,93 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+import io.github.dsheirer.buffer.ComplexCircularBuffer;
+import io.github.dsheirer.sample.complex.Complex;
+
+public class SymbolDecisionData
+{
+    //45 degrees rotation to orient the symbol to a polar axis to make error calculation easy/efficient
+    public static final Complex DIFFERENTIAL_OFFSET = Complex.fromAngle(Math.PI / 4.0d);
+
+    private ComplexCircularBuffer mBuffer;
+    private float mSamplingPoint;
+
+    /**
+     * Circular buffer for capturing two symbols worth of sample data for use in instrumentation.
+     * @param samplesPerSymbol to size the buffer
+     */
+    public SymbolDecisionData(int samplesPerSymbol)
+    {
+        mBuffer = new ComplexCircularBuffer(2 * samplesPerSymbol);
+    }
+
+    /**
+     * Stores the complex sample in the buffer
+     */
+    public void receive(float inphase, float quadrature)
+    {
+        mBuffer.put(new Complex(inphase, quadrature));
+    }
+
+    /**
+     * Stores the complex sample in the buffer
+     */
+    public void receive(Complex complex)
+    {
+        mBuffer.put(complex.copy());
+    }
+
+    /**
+     * Sets the fractional sampling point for the current symbol to use in interpolating the current symbol.
+     */
+    public void setSamplingPoint(float samplingPoint)
+    {
+        mSamplingPoint = samplingPoint;
+    }
+
+    /**
+     * Fractional sampling point
+     */
+    public float getSamplingPoint()
+    {
+        return mSamplingPoint;
+    }
+
+    /**
+     * Array of demodulated samples representing the current symbol where each current sample is demodulated against
+     * the previous symbol's sample to produce the differential demodulated sample.  Samples are in time order.
+     *
+     * Note: differential decoding is on an integral samples-per-symbol basis and does not use fractional interpolation.
+     */
+    public Complex[] getDemodulated()
+    {
+        Complex[] samples = mBuffer.getAll();
+
+        int length = samples.length / 2;
+
+        Complex[] demodulated = new Complex[length];
+
+        for(int x = 0; x < samples.length / 2; x++)
+        {
+            Complex copy = samples[length + x].copy();
+            copy.multiply(samples[x].conjugate());
+            demodulated[x] = copy;
+        }
+
+        return demodulated;
+    }
+}

src/main/java/io/github/dsheirer/dsp/psk/SymbolInversion.java

@@ -0,0 +1,35 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk;
+
+public enum SymbolInversion
+{
+    DEGREES_90_PLUS(Math.PI / 2.0),
+    DEGREES_90_MINUS(Math.PI / -2.0),
+    DEGREES_180(Math.PI);
+
+    private double mAngleRadians;
+
+    SymbolInversion(double angleRadians)
+    {
+        mAngleRadians = angleRadians;
+    }
+
+    public double getError()
+    {
+        return mAngleRadians;
+    }
+}

src/main/java/io/github/dsheirer/dsp/psk/pll/CostasLoop.java

@@ -0,0 +1,182 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk.pll;
+
+import io.github.dsheirer.sample.complex.Complex;
+
+/**
+ * Costas Loop - phase locked loop designed to automatically synchronize to the incoming carrier frequency in order to
+ * zeroize any frequency offset inherent in the signal due to either mis-tuning or carrier frequency drift.
+ *
+ * Costas loop structure was modeled from KA1RBI's OP25/cqpsk.py
+ *
+ * Loop bandwidth and alpha/beta gain formulas derived from:
+ * http://www.trondeau.com/blog/2011/8/13/control-loop-gain-values.html
+ */
+public class CostasLoop implements IPhaseLockedLoop
+{
+    public static final double TWO_PI = 2.0 * Math.PI;
+
+    private Complex mCurrentVector = new Complex(0, 0);
+    private double mLoopPhase = 0.0;
+    private double mLoopFrequency = 0.0;
+    private double mMaximumLoopFrequency;
+    private double mDamping = Math.sqrt(2.0) / 2.0;
+    private double mAlphaGain;
+    private double mBetaGain;
+    private Tracking mTracking = Tracking.NORMAL;
+
+    /**
+     * Costas Loop for tracking and correcting frequency error in a received carrier signal.
+     *
+     * @param sampleRate of the incoming samples
+     * @param symbolRate of the digital signal
+     */
+    public CostasLoop(double sampleRate, double symbolRate)
+    {
+        mMaximumLoopFrequency = TWO_PI * (symbolRate / 2.0) / sampleRate;
+        updateLoopBandwidth();
+    }
+
+    /**
+     * Corrects the current phase tracker when an inverted output is detected.  The inversion will take the form of
+     * +/- 90 degrees or +/- 180 degrees, although the latter correction is equal regardless of the sign.
+     *
+     * If the supplied correction value places the loop frequency outside of the max frequency, then the frequency will
+     * be corrected 360 degrees in the opposite direction to maintain within the max frequency bounds.
+     *
+     * @param correction as measured in radians
+     */
+    public void correctInversion(double correction)
+    {
+        mLoopFrequency += correction;
+
+        while(mLoopFrequency > mMaximumLoopFrequency)
+        {
+            mLoopFrequency -= 2.0 * mMaximumLoopFrequency;
+        }
+
+        while(mLoopFrequency < -mMaximumLoopFrequency)
+        {
+            mLoopFrequency += 2.0 * mMaximumLoopFrequency;
+        }
+    }
+
+    /**
+     * Updates the loop bandwidth and alpha/beta gains according to the current loop synchronization state.
+     */
+    private void updateLoopBandwidth()
+    {
+        double bandwidth = TWO_PI / mTracking.getLoopBandwidth();
+
+        mAlphaGain = (4.0 * mDamping * bandwidth) / (1.0 + (2.0 * mDamping * bandwidth) + (bandwidth * bandwidth));
+        mBetaGain = (4.0 * bandwidth * bandwidth) / (1.0 + (2.0 * mDamping * bandwidth) + (bandwidth * bandwidth));
+    }
+
+    /**
+     * Sets the tracking state for this costas loop.  The tracking state affects the aggressiveness of the alpha/beta
+     * gain values in synchronizing with the signal carrier.
+     *
+     * @param tracking
+     */
+    public void setTracking(Tracking tracking)
+    {
+        mTracking = tracking;
+        updateLoopBandwidth();
+    }
+
+    /**
+     * Increments the phase of the loop for each sample received at the sample rate.
+     */
+    public void increment()
+    {
+        mLoopPhase += mLoopFrequency;
+
+        /* Normalize phase between +/- 2 * PI */
+        if(mLoopPhase > TWO_PI)
+        {
+            mLoopPhase -= TWO_PI;
+        }
+
+        if(mLoopPhase < -TWO_PI)
+        {
+            mLoopPhase += TWO_PI;
+        }
+    }
+
+    /**
+     * Current vector of the loop.  Note: this value is updated for the current angle in radians each time this method
+     * is invoked.
+     */
+    public Complex getCurrentVector()
+    {
+        mCurrentVector.setAngle(mLoopPhase);
+        return mCurrentVector;
+    }
+
+    @Override
+    public Complex incrementAndGetCurrentVector()
+    {
+        increment();
+        return getCurrentVector();
+    }
+
+    public double getLoopFrequency()
+    {
+        return mLoopFrequency;
+    }
+
+    /**
+     * Updates the costas loop frequency and phase to adjust for the phase
+     * error value
+     *
+     * @param phaseError - (-)= late and (+)= early
+     */
+    public void adjust(double phaseError)
+    {
+        mLoopFrequency += (mBetaGain * phaseError);
+        mLoopPhase += mLoopFrequency + (mAlphaGain * phaseError);
+
+        /* Normalize phase between +/- 2 * PI */
+        if(mLoopPhase > TWO_PI)
+        {
+            mLoopPhase -= TWO_PI;
+        }
+
+        if(mLoopPhase < -TWO_PI)
+        {
+            mLoopPhase += TWO_PI;
+        }
+
+        /* Limit frequency to +/- maximum loop frequency */
+        if(mLoopFrequency > mMaximumLoopFrequency)
+        {
+            mLoopFrequency = mMaximumLoopFrequency;
+        }
+
+        if(mLoopFrequency < -mMaximumLoopFrequency)
+        {
+            mLoopFrequency = -mMaximumLoopFrequency;
+        }
+    }
+
+    @Override
+    public void reset()
+    {
+        mLoopPhase = 0.0;
+        mLoopFrequency = 0.0;
+    }
+}

src/main/java/io/github/dsheirer/dsp/psk/pll/IPhaseLockedLoop.java

@@ -0,0 +1,59 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk.pll;
+
+import io.github.dsheirer.sample.complex.Complex;
+
+/**
+ * Phase-Locked Loop (PLL) interface
+ */
+public interface IPhaseLockedLoop
+{
+    /**
+     * Increments the PLL by one sample period
+     */
+    void increment();
+
+    /**
+     * Applies an error value to the PLL.
+     *
+     * @param error value in the range of -PI <> +PI
+     */
+    void adjust(double error);
+
+    /**
+     * Adjusts the current phase of the loop to account for +/-90 or 180 degree inverted phase locks when detected
+     * @param correction to apply to the phase of the loop
+     */
+    void correctInversion(double correction);
+
+    /**
+     * Current vector of the PLL to use in de-spinning the incoming samples.
+     * @return complex vector
+     */
+    Complex getCurrentVector();
+
+    /**
+     * Increments the phase rotation and gets the current vector of the PLL to use in de-spinning the incoming samples.
+     * @return complex vector
+     */
+    Complex incrementAndGetCurrentVector();
+
+    /**
+     * Reset tracking to 0
+     */
+    void reset();
+}

src/main/java/io/github/dsheirer/dsp/psk/pll/Tracking.java

@@ -0,0 +1,42 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.dsp.psk.pll;
+
+/**
+ * Phase Locked Loop (PLL) tracking bandwidth - controls how fast/slow the PLL tracks the carrier frequency
+ */
+public enum Tracking
+{
+    FASTEST(50.0),
+    FAST(100.0),
+    NORMAL(200.0),
+    SLOW(400.0);
+
+    private double mLoopBandwidth;
+
+    Tracking(double loopBandwidth)
+    {
+        mLoopBandwidth = loopBandwidth;
+    }
+
+    /**
+     * Loop bandwidth setting
+     */
+    public double getLoopBandwidth()
+    {
+        return mLoopBandwidth;
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/DecoderSelectionFrame.java

@@ -2,15 +2,19 @@ package io.github.dsheirer.instrument.gui;
 
 import io.github.dsheirer.alias.AliasModel;
 import io.github.dsheirer.audio.broadcast.BroadcastModel;
+import io.github.dsheirer.controller.channel.Channel;
 import io.github.dsheirer.controller.channel.ChannelModel;
 import io.github.dsheirer.controller.channel.map.ChannelMapModel;
 import io.github.dsheirer.module.decode.DecodeConfigurationEditor;
+import io.github.dsheirer.module.decode.config.DecodeConfiguration;
 import io.github.dsheirer.playlist.PlaylistManager;
 import io.github.dsheirer.source.IControllableFileSource;
 import net.miginfocom.swing.MigLayout;
 
-import javax.swing.*;
+import javax.swing.JButton;
-import java.awt.*;
+import javax.swing.JDesktopPane;
+import javax.swing.JInternalFrame;
+import java.awt.Dimension;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 
@@ -18,14 +22,14 @@ public class DecoderSelectionFrame extends JInternalFrame
 {
     private static final long serialVersionUID = 1L;
 
+    private Channel mChannel = new Channel();
     private DecodeConfigurationEditor mDecodeEditor = new DecodeConfigurationEditor(null);
     private PlaylistManager mPlaylistManager;
 
     private IControllableFileSource mSource;
     private JDesktopPane mDesktop;
 
-    public DecoderSelectionFrame(JDesktopPane desktop,
+    public DecoderSelectionFrame(JDesktopPane desktop, IControllableFileSource source)
-                                 IControllableFileSource source)
     {
         AliasModel aliasModel = new AliasModel();
         BroadcastModel broadcastModel = new BroadcastModel(null);
@@ -37,6 +41,7 @@ public class DecoderSelectionFrame extends JInternalFrame
         mDesktop = desktop;
         mSource = source;
 
+        mDecodeEditor.setItem(mChannel);
         initGUI();
     }
 
@@ -72,17 +77,23 @@ public class DecoderSelectionFrame extends JInternalFrame
                 @Override
                 public void actionPerformed(ActionEvent arg0)
                 {
-//					DecodeConfiguration config = mDecodeEditor.getDecodeConfig();
+                    mDecodeEditor.save();
-//					
+
-//					if( config != null )
+                    Channel channel = mDecodeEditor.getItem();
-//					{
+
-//						DecoderViewFrame decoderFrame = new DecoderViewFrame( 
+                    if(channel != null)
-//								mPlaylistManager, null, mSource );
+                    {
-//
+                        DecodeConfiguration config = channel.getDecodeConfiguration();
-//						decoderFrame.setVisible( true );
+
-//						
+                        if( config != null )
-//						mDesktop.add( decoderFrame );
+                        {
-//					}
+                            DecoderViewFrame decoderFrame = new DecoderViewFrame(mPlaylistManager, channel, mSource );
+
+                            decoderFrame.setVisible( true );
+
+                            mDesktop.add( decoderFrame );
+                        }
+                    }
                 }
             });
         }

src/main/java/io/github/dsheirer/instrument/gui/viewer/DemodulatorViewerFX.java

@@ -0,0 +1,183 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer;
+
+import io.github.dsheirer.instrument.gui.viewer.decoder.DecoderPaneFactory;
+import io.github.dsheirer.module.decode.DecoderType;
+import javafx.application.Application;
+import javafx.application.Platform;
+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.scene.Scene;
+import javafx.scene.control.Menu;
+import javafx.scene.control.MenuBar;
+import javafx.scene.control.MenuItem;
+import javafx.scene.control.SeparatorMenuItem;
+import javafx.scene.layout.BorderPane;
+import javafx.stage.FileChooser;
+import javafx.stage.Stage;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.File;
+
+/**
+ * Application for viewing and working with demodulators and recording files.
+ */
+public class DemodulatorViewerFX extends Application
+{
+    private final static Logger mLog = LoggerFactory.getLogger(DemodulatorViewerFX.class);
+
+    private Stage mStage;
+    private MenuBar mMenuBar;
+    private RecentFilesMenu mRecentFilesMenu;
+    private ViewerDesktop mViewerDesktop;
+
+    @Override
+    public void start(Stage primaryStage) throws Exception
+    {
+        mStage = primaryStage;
+        setTitle(null);
+
+        BorderPane borderPane = new BorderPane();
+        borderPane.setTop(getMenuBar());
+        borderPane.setCenter(getViewerDesktop());
+
+        Scene scene = new Scene(borderPane, 1500, 900);
+
+        mStage.setScene(scene);
+        mStage.show();
+    }
+
+    private void setTitle(DecoderType decoderType)
+    {
+        if(decoderType != null)
+        {
+            mStage.setTitle("Demodulator Viewer FX - " + decoderType.getDisplayString());
+        }
+        else
+        {
+            mStage.setTitle("Demodulator Viewer FX");
+        }
+    }
+
+    private ViewerDesktop getViewerDesktop()
+    {
+        if(mViewerDesktop == null)
+        {
+            mViewerDesktop = new ViewerDesktop();
+        }
+
+        return mViewerDesktop;
+    }
+
+    private MenuBar getMenuBar()
+    {
+        if(mMenuBar == null)
+        {
+            mMenuBar = new MenuBar();
+
+            Menu fileMenu = new Menu("File");
+            MenuItem openMenuItem = new MenuItem("Open ...");
+            openMenuItem.setOnAction(new EventHandler<ActionEvent>()
+            {
+                @Override
+                public void handle(ActionEvent event)
+                {
+                    FileChooser fileChooser = new FileChooser();
+                    fileChooser.setTitle("Open an I/Q recording file");
+                    File file = fileChooser.showOpenDialog(mStage);
+                    getViewerDesktop().load(file);
+                    getRecentFilesMenu().add(file);
+                }
+            });
+
+            MenuItem closeMenuItem = new MenuItem("Close");
+            closeMenuItem.setOnAction(new EventHandler<ActionEvent>()
+            {
+                @Override
+                public void handle(ActionEvent event)
+                {
+                    getViewerDesktop().close();
+                }
+            });
+
+            MenuItem exitMenuItem = new MenuItem("Exit");
+            exitMenuItem.setOnAction(new EventHandler<ActionEvent>()
+            {
+                @Override
+                public void handle(ActionEvent event)
+                {
+                    Platform.exit();
+                }
+            });
+
+            fileMenu.getItems().addAll(openMenuItem, getRecentFilesMenu(), closeMenuItem, new SeparatorMenuItem(),
+                    exitMenuItem);
+
+            mMenuBar.getMenus().add(fileMenu);
+
+            Menu decoderMenu = new Menu("Decoder");
+
+            for(DecoderType decoderType: DecoderType.values())
+            {
+                if(DecoderPaneFactory.isSupported(decoderType))
+                {
+                    MenuItem decoderMenuItem = new MenuItem(decoderType.getShortDisplayString());
+
+                    decoderMenuItem.setOnAction(new EventHandler<ActionEvent>()
+                    {
+                        @Override
+                        public void handle(ActionEvent event)
+                        {
+                            getViewerDesktop().setDecoder(decoderType);
+                            setTitle(decoderType);
+                        }
+                    });
+
+                    decoderMenu.getItems().add(decoderMenuItem);
+                }
+            }
+
+            mMenuBar.getMenus().add(decoderMenu);
+        }
+
+        return mMenuBar;
+    }
+
+    private RecentFilesMenu getRecentFilesMenu()
+    {
+        if(mRecentFilesMenu == null)
+        {
+            mRecentFilesMenu = new RecentFilesMenu("Recent","demodulator.viewer", 5);
+            mRecentFilesMenu.setFileSelectionListener(new RecentFilesMenu.IFileSelectionListener()
+            {
+                @Override
+                public void fileSelected(File file)
+                {
+                    getViewerDesktop().load(file);
+                }
+            });
+        }
+
+        return mRecentFilesMenu;
+    }
+
+    public static void main(String[] args)
+    {
+        launch(args);
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/PlaybackController.java

@@ -0,0 +1,311 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer;
+
+import io.github.dsheirer.instrument.gui.viewer.decoder.DecoderPane;
+import io.github.dsheirer.sample.Broadcaster;
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
+import io.github.dsheirer.source.IControllableFileSource;
+import io.github.dsheirer.source.IFrameLocationListener;
+import io.github.dsheirer.source.wave.ComplexWaveSource;
+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.geometry.Pos;
+import javafx.scene.control.Alert;
+import javafx.scene.control.Button;
+import javafx.scene.control.ButtonType;
+import javafx.scene.control.Label;
+import javafx.scene.control.TextField;
+import javafx.scene.layout.HBox;
+import org.kordamp.ikonli.fontawesome.FontAwesome;
+import org.kordamp.ikonli.javafx.FontIcon;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.sound.sampled.UnsupportedAudioFileException;
+import java.io.File;
+import java.io.IOException;
+
+public class PlaybackController extends HBox implements IFrameLocationListener, Listener<ComplexBuffer>
+{
+    private final static Logger mLog = LoggerFactory.getLogger(PlaybackController.class);
+
+    private Button mRewindButton;
+    private TextField mPlaybackPositionText;
+    private Button mPlay1Button;
+    private Button mPlay10Button;
+    private Button mPlay100Button;
+    private Button mPlay1000Button;
+    private HBox mControlsBox;
+    private Label mFileLabel;
+    private EventHandler<ActionEvent> mPlayEventHandler;
+    private DecoderPane mSampleRateListener;
+
+    private IControllableFileSource mControllableFileSource;
+    private Broadcaster<ComplexBuffer> mComplexBufferBroadcaster = new Broadcaster<>();
+
+    public PlaybackController()
+    {
+        super(10);
+
+        getChildren().addAll(getControlsBox(), getFileLabel());
+
+        setControlsEnabled(false);
+    }
+
+    public void setSampleRateListener(DecoderPane decoderPane)
+    {
+        mSampleRateListener = decoderPane;
+
+        if(mSampleRateListener != null && mControllableFileSource != null)
+        {
+            mSampleRateListener.setSampleRate(mControllableFileSource.getSampleRate());
+        }
+    }
+
+    public void load(File file)
+    {
+        if(file != null && file.isFile())
+        {
+            try
+            {
+                mControllableFileSource = new ComplexWaveSource(file);
+                mControllableFileSource.setListener(this);
+                ((ComplexWaveSource)mControllableFileSource).setListener((Listener<ComplexBuffer>)this);
+                mControllableFileSource.open();
+
+                if(mSampleRateListener != null)
+                {
+                    mSampleRateListener.setSampleRate(mControllableFileSource.getSampleRate());
+                }
+            }
+            catch(UnsupportedAudioFileException e)
+            {
+                mLog.error("Unsupported Audio File Type [" + (file != null ? file.getAbsolutePath() : "null") + "]");
+
+                Alert alert = new Alert(Alert.AlertType.ERROR, "The file type is unsupported.", ButtonType.OK);
+                alert.show();
+                return;
+            }
+            catch(IOException ioe)
+            {
+                mLog.error("Error opening file [" + (file != null ? file.getAbsolutePath() : "null") + "]", ioe);
+
+                Alert alert = new Alert(Alert.AlertType.ERROR, "There was an error opening the file",
+                    ButtonType.OK);
+                alert.show();
+                return;
+            }
+
+            getFileLabel().setText(file.getName());
+            setControlsEnabled(true);
+        }
+    }
+
+    public void close()
+    {
+        if(mControllableFileSource != null)
+        {
+            try
+            {
+                mControllableFileSource.close();
+            }
+            catch(IOException ioe)
+            {
+                mLog.error("Error closing file", ioe);
+            }
+        }
+
+        setControlsEnabled(false);
+    }
+
+    /**
+     * Adds listener to receive complex buffers from this playback
+     */
+    public void addListener(Listener<ComplexBuffer> listener)
+    {
+        mComplexBufferBroadcaster.addListener(listener);
+    }
+
+    /**
+     * Removes the listener from receiving complex buffers from this playback
+     */
+    public void removeListener(Listener<ComplexBuffer> listener)
+    {
+        mComplexBufferBroadcaster.removeListener(listener);
+    }
+
+    /**
+     * Sets all of the playback controls to the specified enabled state.
+     */
+    private void setControlsEnabled(boolean enabled)
+    {
+        getRewindButton().setDisable(!enabled);
+        getPlaybackPositionText().setDisable(!enabled);
+        getPlay1Button().setDisable(!enabled);
+        getPlay10Button().setDisable(!enabled);
+        getPlay100Button().setDisable(!enabled);
+        getPlay1000Button().setDisable(!enabled);
+    }
+
+    private HBox getControlsBox()
+    {
+        if(mControlsBox == null)
+        {
+            mControlsBox = new HBox();
+
+            mControlsBox.getChildren().addAll(getRewindButton(), getPlaybackPositionText(), getPlay1Button(),
+                getPlay10Button(), getPlay100Button(), getPlay1000Button());
+        }
+
+        return mControlsBox;
+    }
+
+
+    private  Button getRewindButton()
+    {
+        if(mRewindButton == null)
+        {
+            mRewindButton = new Button();
+            mRewindButton.setGraphic(new FontIcon(FontAwesome.FAST_BACKWARD));
+        }
+
+        return mRewindButton;
+    }
+
+    private  Button getPlay1Button()
+    {
+        if(mPlay1Button == null)
+        {
+            mPlay1Button = new Button("1");
+            mPlay1Button.setUserData(1);
+            mPlay1Button.setOnAction(getPlaybackEventHandler());
+            mPlay1Button.setGraphic(new FontIcon(FontAwesome.PLAY));
+        }
+
+        return mPlay1Button;
+    }
+
+    private  Button getPlay10Button()
+    {
+        if(mPlay10Button == null)
+        {
+            mPlay10Button = new Button("10");
+            mPlay10Button.setUserData(10);
+            mPlay10Button.setOnAction(getPlaybackEventHandler());
+            mPlay10Button.setGraphic(new FontIcon(FontAwesome.FAST_FORWARD));
+        }
+
+        return mPlay10Button;
+    }
+
+    private  Button getPlay100Button()
+    {
+        if(mPlay100Button == null)
+        {
+            mPlay100Button = new Button("100");
+            mPlay100Button.setUserData(100);
+            mPlay100Button.setOnAction(getPlaybackEventHandler());
+            mPlay100Button.setGraphic(new FontIcon(FontAwesome.FAST_FORWARD));
+        }
+
+        return mPlay100Button;
+    }
+
+    private  Button getPlay1000Button()
+    {
+        if(mPlay1000Button == null)
+        {
+            mPlay1000Button = new Button("1000");
+            mPlay1000Button.setUserData(1000);
+            mPlay1000Button.setOnAction(getPlaybackEventHandler());
+            mPlay1000Button.setGraphic(new FontIcon(FontAwesome.FAST_FORWARD));
+        }
+
+        return mPlay1000Button;
+    }
+
+    private EventHandler<ActionEvent> getPlaybackEventHandler()
+    {
+        if(mPlayEventHandler == null)
+        {
+            mPlayEventHandler = new EventHandler<ActionEvent>()
+            {
+                @Override
+                public void handle(ActionEvent event)
+                {
+                    int count = (int)((Button)event.getSource()).getUserData();
+
+                    if(mControllableFileSource != null)
+                    {
+                        try
+                        {
+                            mControllableFileSource.next(count, true);
+                        }
+                        catch(IOException ioe)
+                        {
+                            mLog.error("Error while playing samples");
+                        }
+                    }
+
+                }
+            };
+        }
+
+        return mPlayEventHandler;
+    }
+
+    private  TextField getPlaybackPositionText()
+    {
+        if(mPlaybackPositionText == null)
+        {
+            mPlaybackPositionText = new TextField("0");
+            mPlaybackPositionText.setAlignment(Pos.CENTER);
+            mPlaybackPositionText.setPrefWidth(80);
+        }
+
+        return mPlaybackPositionText;
+    }
+
+    private  Label getFileLabel()
+    {
+        if(mFileLabel == null)
+        {
+            mFileLabel = new Label();
+        }
+
+        return mFileLabel;
+    }
+
+    @Override
+    public void frameLocationUpdated(int location)
+    {
+        getPlaybackPositionText().setText(String.valueOf(location));
+    }
+
+    @Override
+    public void frameLocationReset()
+    {
+        mLog.info("Frame location reset ... ignoring?");
+    }
+
+    @Override
+    public void receive(ComplexBuffer complexBuffer)
+    {
+        mComplexBufferBroadcaster.broadcast(complexBuffer);
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/RecentFilesMenu.java

@@ -0,0 +1,192 @@
+package io.github.dsheirer.instrument.gui.viewer;
+
+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.scene.control.Menu;
+import javafx.scene.control.MenuItem;
+import javafx.scene.control.SeparatorMenuItem;
+
+import java.io.File;
+import java.util.prefs.Preferences;
+
+public class RecentFilesMenu extends Menu implements EventHandler<ActionEvent>
+{
+    private Preferences mPreferences = Preferences.userNodeForPackage(RecentFilesMenu.class);
+    private IFileSelectionListener mFileSelectionListener;
+    private String mIdentifier;
+    private int mSize;
+
+    /**
+     * Recently used files menu.  Uses java Preferences to store recently accessed files and provides access to those
+     * files via child menu items to this menu.
+     *
+     * @param label to use for this menu.
+     * @param uniqueIdentifier to use in addition to the class path of this class to uniquely identify recently accessed
+     * files in a java Preferences data store.
+     * @param size of the maximum number of recent files to present to the user
+     */
+    public RecentFilesMenu(String label, String uniqueIdentifier, int size)
+    {
+        super(label);
+        mIdentifier = uniqueIdentifier;
+        mSize = size;
+
+        load();
+    }
+
+    /**
+     * Registers the listener to receive file selection events when the user selects a recently used file.
+     * @param listener to receive file selection events
+     */
+    public void setFileSelectionListener(IFileSelectionListener listener)
+    {
+        mFileSelectionListener = listener;
+    }
+
+    /**
+     * Adds the file to the recently accessed files list.  If this file is already included in the recently files list,
+     * it will be promoted to the first menu item and all other recently used files will be demoted.
+     *
+     * @param file to add to the recently used files list.
+     */
+    public void add(File file)
+    {
+        if(file != null)
+        {
+            String filePath = file.getAbsolutePath();
+
+            int index = mSize - 1;
+
+            //Check to see if this file is already in the recent files list
+            for(int x = mSize - 1; x >= 0; x--)
+            {
+                String existingItem = mPreferences.get(getKey(x), null);
+
+                if(existingItem != null && existingItem.equals(filePath))
+                {
+                    index = x;
+                    break;
+                }
+            }
+
+            //Shift all recent files down to make room for the newly added file at the top of the list
+            while(index > 0)
+            {
+                String newerItem = mPreferences.get(getKey(index - 1), null);
+
+                if(newerItem != null)
+                {
+                    mPreferences.put(getKey(index), newerItem);
+                }
+
+                index--;
+            }
+
+            mPreferences.put(getKey(0), file.getAbsolutePath());
+        }
+
+        load();
+    }
+
+    /**
+     * Creates a unique key value for each numbered recently used file item in the preferences.
+     *
+     * @param index of recent file item.
+     * @return unique key to use with the preferences instance.
+     */
+    private String getKey(int index)
+    {
+        return mIdentifier + ".recent.file." + index;
+    }
+
+    /**
+     * Clears and (re)loads all child recent file menu items.
+     */
+    private void load()
+    {
+        getItems().clear();
+
+        for(int x = 0; x < mSize; x++)
+        {
+            String path = mPreferences.get(getKey(x), null);
+
+            if(path != null)
+            {
+                File file = new File(path);
+
+                if(file.isFile())
+                {
+                    MenuItem menuItem = new MenuItem(file.getName());
+                    menuItem.setUserData(file);
+                    menuItem.setOnAction(this);
+                    getItems().add(menuItem);
+                }
+            }
+        }
+
+        if(getItems().size() > 0)
+        {
+            setDisable(false);
+            getItems().add(new SeparatorMenuItem());
+
+            MenuItem clearMenuItem = new MenuItem("Clear History");
+            clearMenuItem.setOnAction(new EventHandler<ActionEvent>()
+            {
+                @Override
+                public void handle(ActionEvent event)
+                {
+                    clearHistory();
+                }
+            });
+            getItems().add(clearMenuItem);
+        }
+        else
+        {
+            setDisable(true);
+        }
+    }
+
+    /**
+     * Clears the recently used files history and removes all items from the preferences instance
+     */
+    private void clearHistory()
+    {
+        for(int x = 0; x < mSize; x++)
+        {
+            mPreferences.remove(getKey(x));
+        }
+
+        load();
+    }
+
+    /**
+     * Event handler for all recent file child menu items.  Extracts the selected file stored as the user data object
+     * in each of the menu items and notifies the listener that the recent file has been selected.
+     *
+     * @param event from a recent file menu item child of this menu.
+     */
+    @Override
+    public void handle(ActionEvent event)
+    {
+        if(mFileSelectionListener != null)
+        {
+            if(event.getSource() instanceof MenuItem)
+            {
+                Object fileObject = ((MenuItem)event.getSource()).getUserData();
+
+                if(fileObject instanceof File)
+                {
+                    mFileSelectionListener.fileSelected((File)fileObject);
+                }
+            }
+        }
+    }
+
+    /**
+     * Listener interface for file selection events.
+     */
+    public interface IFileSelectionListener
+    {
+        void fileSelected(File file);
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/ViewerDesktop.java

@@ -0,0 +1,81 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer;
+
+import io.github.dsheirer.instrument.gui.viewer.decoder.DecoderPane;
+import io.github.dsheirer.instrument.gui.viewer.decoder.DecoderPaneFactory;
+import io.github.dsheirer.module.decode.DecoderType;
+import javafx.scene.layout.BorderPane;
+
+import java.io.File;
+
+public class ViewerDesktop extends BorderPane
+{
+    private PlaybackController mPlaybackController;
+    private DecoderPane mDecoderPane = DecoderPaneFactory.getDefaultPane();
+
+    public ViewerDesktop()
+    {
+        setBottom(getPlaybackController());
+        setCenter(getDecoderPane());
+    }
+
+    public void load(File file)
+    {
+        close();
+        getPlaybackController().load(file);
+    }
+
+    public void setDecoder(DecoderType decoderType)
+    {
+        getPlaybackController().removeListener(getDecoderPane());
+        getChildren().remove(getDecoderPane());
+
+        mDecoderPane = DecoderPaneFactory.getDecoderPane(decoderType);
+        setCenter(getDecoderPane());
+        getPlaybackController().addListener(getDecoderPane());
+
+        getPlaybackController().setSampleRateListener(getDecoderPane());
+    }
+
+    /**
+     * Decoder pane
+     */
+    public DecoderPane getDecoderPane()
+    {
+        if(mDecoderPane == null)
+        {
+            mDecoderPane = DecoderPaneFactory.getDefaultPane();
+        }
+
+        return mDecoderPane;
+    }
+
+    public void close()
+    {
+        getPlaybackController().close();
+    }
+
+    private PlaybackController getPlaybackController()
+    {
+        if(mPlaybackController == null)
+        {
+            mPlaybackController = new PlaybackController();
+        }
+
+        return mPlaybackController;
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/chart/ComplexPhaseLineChart.java

@@ -0,0 +1,121 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer.chart;
+
+import io.github.dsheirer.buffer.ComplexCircularBuffer;
+import io.github.dsheirer.dsp.gain.ComplexGain;
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.Complex;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
+import javafx.beans.property.IntegerProperty;
+import javafx.beans.property.SimpleIntegerProperty;
+import javafx.beans.value.ChangeListener;
+import javafx.beans.value.ObservableValue;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.scene.chart.LineChart;
+import javafx.scene.chart.NumberAxis;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ComplexPhaseLineChart extends LineChart implements Listener<ComplexBuffer>
+{
+    private final static Logger mLog = LoggerFactory.getLogger(ComplexPhaseLineChart.class);
+
+    private static final Complex ANGLE_OFFSET_45_DEGREES = Complex.fromAngle(Math.PI / 4.0);
+    private ComplexCircularBuffer mComplexCircularBuffer;
+    private ComplexGain mComplexGain = new ComplexGain(600.0f);
+    private ObservableList<Data<Integer,Float>> mPhaseValues = FXCollections.observableArrayList();
+    private IntegerProperty mLengthProperty = new SimpleIntegerProperty(40);
+
+    public ComplexPhaseLineChart(int length)
+    {
+        super(new NumberAxis("Time", 1, length - 10, 2),
+            new NumberAxis("Phase", -Math.PI, Math.PI, Math.PI / 2.0));
+
+        Series<Integer,Float> phaseSeries = new Series<>("Phase", mPhaseValues);
+        ObservableList<Series<Integer,Float>> observableList = FXCollections.observableArrayList(phaseSeries);
+
+        setData(observableList);
+        init(length);
+    }
+
+    private void init(int length)
+    {
+        mLengthProperty.addListener(new ChangeListener<Number>()
+        {
+            @Override
+            public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue)
+            {
+                mComplexCircularBuffer = new ComplexCircularBuffer(newValue.intValue());
+            }
+        });
+        mComplexCircularBuffer = new ComplexCircularBuffer(length);
+        length().setValue(length);
+
+        for(int x = 10; x <= length; x++)
+        {
+            mPhaseValues.add(new Data(x - 10, 0.0f));
+        }
+    }
+
+    /**
+     * Length of the x-axis for displaying samples
+     */
+    public IntegerProperty length()
+    {
+        return mLengthProperty;
+    }
+
+    @Override
+    public void receive(ComplexBuffer complexBuffer)
+    {
+        float[] samples = complexBuffer.getSamples();
+
+        Complex sample;
+
+        for(int x = 0; x < samples.length; x += 2)
+        {
+            sample = new Complex(samples[x], samples[x + 1]);
+            Complex copy = sample.copy();
+            mComplexGain.apply(copy);
+            mComplexCircularBuffer.put(copy);
+        }
+
+        updateChart();
+    }
+
+    private void updateChart()
+    {
+        Complex[] samples = mComplexCircularBuffer.getAll();
+
+        for(int x = 10; x < samples.length; x++)
+        {
+            Complex previous = samples[x - 10].copy();
+            Complex sample = samples[x].copy();
+
+            if(previous != null && sample != null)
+            {
+//                previous.normalize();
+//                sample.normalize();
+                previous.add(ANGLE_OFFSET_45_DEGREES);
+                sample.multiply(previous.conjugate());
+//                sample.normalize();
+                mPhaseValues.get(x - 9).setYValue(sample.angle());
+            }
+        }
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/chart/ComplexSampleLineChart.java

@@ -0,0 +1,131 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer.chart;
+
+import io.github.dsheirer.buffer.ComplexCircularBuffer;
+import io.github.dsheirer.dsp.gain.ComplexGain;
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.Complex;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
+import javafx.beans.property.IntegerProperty;
+import javafx.beans.property.SimpleIntegerProperty;
+import javafx.beans.value.ChangeListener;
+import javafx.beans.value.ObservableValue;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.scene.chart.LineChart;
+import javafx.scene.chart.NumberAxis;
+import javafx.scene.chart.XYChart;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ComplexSampleLineChart extends LineChart implements Listener<ComplexBuffer>
+{
+    private final static Logger mLog = LoggerFactory.getLogger(ComplexSampleLineChart.class);
+
+    private ComplexCircularBuffer mComplexCircularBuffer;
+    private ComplexCircularBuffer mDemodulationCircularBuffer;
+    private ComplexGain mComplexGain = new ComplexGain(500.0f);
+    private ObservableList<XYChart.Data<Integer,Float>> mISamples = FXCollections.observableArrayList();
+    private ObservableList<XYChart.Data<Integer,Float>> mQSamples = FXCollections.observableArrayList();
+    private IntegerProperty mLengthProperty = new SimpleIntegerProperty(40);
+
+    public ComplexSampleLineChart(int length, int samplesPerSymbol)
+    {
+        super(new NumberAxis("Differential-Demodulated Samples", 0, length, 10),
+            new NumberAxis("Value", -1.0, 1.0, 0.25));
+
+        LineChart.Series<Integer,Float> iSampleSeries = new LineChart.Series<>("Inphase", mISamples);
+        LineChart.Series<Integer,Float> qSampleSeries = new LineChart.Series<>("Quadrature", mQSamples);
+        ObservableList<XYChart.Series<Integer,Float>> observableList =
+            FXCollections.observableArrayList(iSampleSeries, qSampleSeries);
+
+        setData(observableList);
+        init(length, samplesPerSymbol);
+    }
+
+    public void setSamplesPerSymbol(int samplesPerSymbol)
+    {
+        mDemodulationCircularBuffer = new ComplexCircularBuffer(samplesPerSymbol);
+    }
+
+    private void init(int length, int samplesPerSymbol)
+    {
+        mLengthProperty.addListener(new ChangeListener<Number>()
+        {
+            @Override
+            public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue)
+            {
+                mComplexCircularBuffer = new ComplexCircularBuffer(newValue.intValue());
+            }
+        });
+        mComplexCircularBuffer = new ComplexCircularBuffer(length);
+        mDemodulationCircularBuffer = new ComplexCircularBuffer(samplesPerSymbol);
+        length().setValue(length);
+
+        for(int x = 1; x <= length; x++)
+        {
+            mISamples.add(new Data(x, 0.0f));
+            mQSamples.add(new Data(x, 0.0f));
+        }
+    }
+
+    /**
+     * Length of the x-axis for displaying samples
+     */
+    public IntegerProperty length()
+    {
+        return mLengthProperty;
+    }
+
+    @Override
+    public void receive(ComplexBuffer complexBuffer)
+    {
+        float[] samples = complexBuffer.getSamples();
+
+        Complex sample = new Complex(0,0);
+
+        for(int x = 0; x < samples.length; x += 2)
+        {
+            sample.setValues(samples[x], samples[x + 1]);
+//            mComplexGain.apply(sample);
+            sample.normalize();
+
+            Complex previous = mDemodulationCircularBuffer.get(sample.copy());
+            sample.multiply(previous.conjugate());
+            mComplexCircularBuffer.put(sample.copy());
+        }
+
+        updateChart();
+    }
+
+    private void updateChart()
+    {
+        Complex[] samples = mComplexCircularBuffer.getAll();
+
+        for(int x = 0; x < samples.length; x++)
+        {
+            Complex sample = samples[x];
+
+            if(sample != null)
+            {
+                sample.normalize();
+                mISamples.get(x).setYValue(sample.inphase());
+                mQSamples.get(x).setYValue(sample.quadrature());
+            }
+        }
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/chart/DoubleLineChart.java

@@ -0,0 +1,72 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer.chart;
+
+import io.github.dsheirer.buffer.DoubleCircularBuffer;
+import io.github.dsheirer.sample.Listener;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.scene.chart.LineChart;
+import javafx.scene.chart.NumberAxis;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class DoubleLineChart extends LineChart implements Listener<Double>
+{
+    private final static Logger mLog = LoggerFactory.getLogger(DoubleLineChart.class);
+
+    private DoubleCircularBuffer mDoubleCircularBuffer;
+    private ObservableList<Data<Integer,Double>> mPhaseValues = FXCollections.observableArrayList();
+
+    public DoubleLineChart(String seriesLabel, double min, double max, double tick, int length)
+    {
+        super(new NumberAxis(1, length, 2), new NumberAxis(min, max, tick));
+
+        Series<Integer,Double> phaseSeries = new Series<>(seriesLabel, mPhaseValues);
+        ObservableList<Series<Integer,Double>> observableList = FXCollections.observableArrayList(phaseSeries);
+
+        setData(observableList);
+        init(length);
+    }
+
+    private void init(int length)
+    {
+        mDoubleCircularBuffer = new DoubleCircularBuffer(length);
+
+        for(int x = 1; x <= length; x++)
+        {
+            mPhaseValues.add(new Data(x, 0.0));
+        }
+    }
+
+    @Override
+    public void receive(Double phase)
+    {
+        mDoubleCircularBuffer.put(phase);
+
+        updateChart();
+    }
+
+    private void updateChart()
+    {
+        double[] values = mDoubleCircularBuffer.getAll();
+
+        for(int x = 0; x < values.length; x++)
+        {
+            mPhaseValues.get(x).setYValue(values[x]);
+        }
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/chart/EyeDiagramChart.java

@@ -0,0 +1,121 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer.chart;
+
+import io.github.dsheirer.dsp.psk.SymbolDecisionData;
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.Complex;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.scene.chart.LineChart;
+import javafx.scene.chart.NumberAxis;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class EyeDiagramChart extends LineChart implements Listener<SymbolDecisionData>
+{
+    private final static Logger mLog = LoggerFactory.getLogger(EyeDiagramChart.class);
+
+    private ObservableList<Series<Double,Double>> mData = FXCollections.observableArrayList();
+    private int mSeriesCount;
+    private int mSeriesPointer;
+    private int mSeriesLength;
+
+    public EyeDiagramChart(int seriesCount)
+    {
+        super(new NumberAxis("Symbol Timing (5 = center)", 1.0, 10.0, 1.0),
+            new NumberAxis("Value", -1.25, 1.25, 0.25));
+
+        mSeriesCount = seriesCount * 2;
+        init();
+    }
+
+    private void init()
+    {
+        for(int x = 0; x < mSeriesCount; x++)
+        {
+            ObservableList<Data<Double,Double>> series = FXCollections.observableArrayList();
+            mData.add(new Series<>(series));
+        }
+
+        setData(mData);
+    }
+
+    private ObservableList<Data<Double,Double>> getSeries(int series, int length)
+    {
+        ObservableList<Data<Double,Double>> seriesData = mData.get(series).getData();
+
+        while(seriesData.size() > length)
+        {
+            seriesData.remove(0);
+        }
+
+        while(seriesData.size() < length)
+        {
+            seriesData.add(new Data<Double,Double>(0.0,0.0));
+        }
+
+        return seriesData;
+    }
+
+    private void checkChartLength(int length)
+    {
+        if(mSeriesLength != length)
+        {
+            ((NumberAxis)getXAxis()).setUpperBound(length);
+            mSeriesLength = length;
+        }
+    }
+
+    @Override
+    public void receive(SymbolDecisionData symbolDecisionData)
+    {
+        Complex[] demodulated = symbolDecisionData.getDemodulated();
+
+        int length = demodulated.length;
+
+        checkChartLength(length);
+
+
+        ObservableList<Data<Double,Double>> iSeries = getSeries(mSeriesPointer++, length + 1);
+
+        if(mSeriesPointer >= mSeriesCount)
+        {
+            mSeriesPointer = 0;
+        }
+
+        ObservableList<Data<Double,Double>> qSeries = getSeries(mSeriesPointer++, length + 1);
+
+        if(mSeriesPointer >= mSeriesCount)
+        {
+            mSeriesPointer = 0;
+        }
+
+        for(int x = 0; x < length; x++)
+        {
+            demodulated[x].normalize();
+            Data<Double,Double> iDataPoint = iSeries.get(x);
+            iDataPoint.setXValue((double)x + 1 - symbolDecisionData.getSamplingPoint());
+            double iValue = demodulated[x].inphase();
+            iDataPoint.setYValue(iValue);
+
+            Data<Double,Double> qDataPoint = qSeries.get(x);
+            qDataPoint.setXValue((double)x + 1 - symbolDecisionData.getSamplingPoint());
+            double qValue = demodulated[x].quadrature();
+            qDataPoint.setYValue(qValue);
+        }
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/chart/FMDemodulatedLineChart.java

@@ -0,0 +1,119 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer.chart;
+
+import io.github.dsheirer.buffer.DoubleCircularBuffer;
+import io.github.dsheirer.dsp.fm.FMDemodulator;
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.Complex;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.scene.chart.LineChart;
+import javafx.scene.chart.NumberAxis;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class FMDemodulatedLineChart extends LineChart implements Listener<ComplexBuffer>
+{
+    private final static Logger mLog = LoggerFactory.getLogger(FMDemodulatedLineChart.class);
+
+    private DoubleCircularBuffer mDoubleCircularBuffer;
+    private int mSamplesPerSymbol;
+    private int mTwiceSamplesPerSymbol;
+    private int mSeriesCount;
+    private ObservableList<Series<Integer,Double>> mData = FXCollections.observableArrayList();
+    private Complex mPreviousSample = new Complex(0,0);
+    private int mSeriesPointer;
+    private int mSamplePointer;
+
+    public FMDemodulatedLineChart(int samplesPerSymbol, int seriesCount)
+    {
+        super(new NumberAxis("Time", 1, samplesPerSymbol * 2, 2),
+            new NumberAxis("Demodulated", -1.0, 1.0, 0.25));
+
+        mSamplesPerSymbol = samplesPerSymbol;
+        mTwiceSamplesPerSymbol = mSamplesPerSymbol * 2;
+        mSeriesCount = seriesCount;
+
+        init();
+    }
+
+    private void init()
+    {
+        int seriesLength = 2 * mSamplesPerSymbol;
+        mDoubleCircularBuffer = new DoubleCircularBuffer(seriesLength * mSeriesCount);
+
+        for(int x = 0; x < mSeriesCount; x++)
+        {
+            ObservableList<Data<Integer,Double>> series = FXCollections.observableArrayList();
+
+            for(int y = 0; y < seriesLength; y++)
+            {
+                series.add(new Data<Integer,Double>(y + 1, 0.0));
+            }
+
+            mData.add(new Series<>(series));
+        }
+
+        setData(mData);
+    }
+
+    @Override
+    public void receive(ComplexBuffer complexBuffer)
+    {
+        float[] samples = complexBuffer.getSamples();
+
+        Complex sample;
+
+        for(int x = 0; x < samples.length; x += 2)
+        {
+            sample = new Complex(samples[x], samples[x + 1]);
+            double demodulated = FMDemodulator.demodulate(mPreviousSample, sample);
+            demodulated *= 2.0;
+
+            if(demodulated > 1.0)
+            {
+                demodulated = 1.0;
+            }
+            else if(demodulated < -1.0)
+            {
+                demodulated = -1.0;
+            }
+            mDoubleCircularBuffer.put(demodulated);
+            mPreviousSample = sample;
+            updateChart(demodulated);
+        }
+    }
+
+    private void updateChart(double value)
+    {
+        Series<Integer,Double> series = mData.get(mSeriesPointer);
+        Data data = series.getData().get(mSamplePointer++);
+        data.setYValue(value);
+
+        if(mSamplePointer >= mTwiceSamplesPerSymbol)
+        {
+            mSamplePointer = 0;
+            mSeriesPointer++;
+
+            if(mSeriesPointer >= mSeriesCount)
+            {
+                mSeriesPointer = 0;
+            }
+        }
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/chart/PhaseLineChart.java

@@ -0,0 +1,73 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer.chart;
+
+import io.github.dsheirer.buffer.DoubleCircularBuffer;
+import io.github.dsheirer.sample.Listener;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.scene.chart.LineChart;
+import javafx.scene.chart.NumberAxis;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class PhaseLineChart extends LineChart implements Listener<Double>
+{
+    private final static Logger mLog = LoggerFactory.getLogger(PhaseLineChart.class);
+
+    private DoubleCircularBuffer mDoubleCircularBuffer;
+    private ObservableList<Data<Integer,Double>> mPhaseValues = FXCollections.observableArrayList();
+
+    public PhaseLineChart(int length)
+    {
+        super(new NumberAxis("Time", 1, length, 2),
+            new NumberAxis("Phase", -0.8, 0.8, 0.1));
+
+        Series<Integer,Double> phaseSeries = new Series<>("PLL Phase Error", mPhaseValues);
+        ObservableList<Series<Integer,Double>> observableList = FXCollections.observableArrayList(phaseSeries);
+
+        setData(observableList);
+        init(length);
+    }
+
+    private void init(int length)
+    {
+        mDoubleCircularBuffer = new DoubleCircularBuffer(length);
+
+        for(int x = 1; x <= length; x++)
+        {
+            mPhaseValues.add(new Data(x, 0.0));
+        }
+    }
+
+    @Override
+    public void receive(Double phase)
+    {
+        mDoubleCircularBuffer.put(phase);
+
+        updateChart();
+    }
+
+    private void updateChart()
+    {
+        double[] values = mDoubleCircularBuffer.getAll();
+
+        for(int x = 0; x < values.length; x++)
+        {
+            mPhaseValues.get(x).setYValue(values[x]);
+        }
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/chart/SymbolChart.java

@@ -0,0 +1,90 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer.chart;
+
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.Complex;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.scene.chart.NumberAxis;
+import javafx.scene.chart.ScatterChart;
+import javafx.scene.chart.XYChart;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class SymbolChart extends ScatterChart implements Listener<Complex>
+{
+    private final static Logger mLog = LoggerFactory.getLogger(SymbolChart.class);
+
+    private ObservableList<ScatterChart.Data> mCurrentPoints = FXCollections.observableArrayList();
+//    private ObservableList<ScatterChart.Data> mPreviousPoints = FXCollections.observableArrayList();
+//    private ObservableList<ScatterChart.Data> mOldestPoints = FXCollections.observableArrayList();
+    private int mDataPointer;
+    private int mHistory;
+
+    /**
+     * Symbol chart for plotting a series of constellation symbols over time.  Maintains three history sets for
+     * current, previous, and oldest symbols.
+     *
+     * @param history size for each of the history sets
+     */
+    public SymbolChart(int history)
+    {
+        super(new NumberAxis("I", -1.1, 1.1, 0.2),
+            new NumberAxis("Q", -1.1, 1.1, 0.2));
+
+        mHistory = history;
+
+        for(int x = 0; x < mHistory; x++)
+        {
+            mCurrentPoints.add(new XYChart.Data<>(0.0, 0.0));
+//            mPreviousPoints.add(new XYChart.Data<>(0.0, 0.0));
+//            mOldestPoints.add(new XYChart.Data<>(0.0, 0.0));
+        }
+
+        ObservableList<XYChart.Series> data = FXCollections.observableArrayList();
+        data.add(new ScatterChart.Series("Constellation", mCurrentPoints));
+//        data.add(new ScatterChart.Series("Previous", mPreviousPoints));
+//        data.add(new ScatterChart.Series("Oldest", mOldestPoints));
+
+        this.setData(data);
+    }
+
+    @Override
+    public void receive(Complex complex)
+    {
+        //Transfer previous to oldest
+//        XYChart.Data oldest = mOldestPoints.get(mDataPointer);
+//        XYChart.Data previous = mPreviousPoints.get(mDataPointer);
+        XYChart.Data current = mCurrentPoints.get(mDataPointer);
+
+//        oldest.setXValue(previous.getXValue());
+//        oldest.setYValue(previous.getYValue());
+//
+//        previous.setXValue(current.getXValue());
+//        previous.setYValue(current.getYValue());
+
+        current.setXValue(complex.inphase());
+        current.setYValue(complex.quadrature());
+
+        mDataPointer++;
+
+        if(mDataPointer >= mHistory)
+        {
+            mDataPointer = 0;
+        }
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/decoder/DecoderPane.java

@@ -0,0 +1,62 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer.decoder;
+
+import io.github.dsheirer.module.decode.DecoderType;
+import io.github.dsheirer.sample.Broadcaster;
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
+import javafx.scene.layout.VBox;
+import javafx.scene.text.Text;
+
+public class DecoderPane extends VBox implements Listener<ComplexBuffer>
+{
+    private Broadcaster<ComplexBuffer> mComplexBufferBroadcaster = new Broadcaster<>();
+    private DecoderType mDecoderType;
+
+    public DecoderPane(DecoderType decoderType)
+    {
+        mDecoderType = decoderType;
+    }
+
+    /**
+     * Package private - used by factory class to create an empty pane
+     */
+    DecoderPane()
+    {
+        getChildren().add(new Text("Please select a decoder from the menu"));
+    }
+
+    @Override
+    public void receive(ComplexBuffer complexBuffer)
+    {
+        mComplexBufferBroadcaster.broadcast(complexBuffer);
+    }
+
+    public void addListener(Listener<ComplexBuffer> listener)
+    {
+        mComplexBufferBroadcaster.addListener(listener);
+    }
+
+    public void removeListener(Listener<ComplexBuffer> listener)
+    {
+        mComplexBufferBroadcaster.removeListener(listener);
+    }
+
+    public void setSampleRate(double sampleRate)
+    {
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/decoder/DecoderPaneFactory.java

@@ -0,0 +1,55 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer.decoder;
+
+import io.github.dsheirer.module.decode.DecoderType;
+
+import java.util.EnumSet;
+
+public class DecoderPaneFactory
+{
+    private static final EnumSet<DecoderType> SUPPORTED_DECODER_TYPES = EnumSet.of(DecoderType.P25_PHASE1);
+
+    /**
+     * Creates a decoder pane for the decoder type
+     */
+    public static DecoderPane getDecoderPane(DecoderType decoderType)
+    {
+        switch(decoderType)
+        {
+            case P25_PHASE1:
+                return new P25Phase1Pane();
+        }
+
+        return getDefaultPane();
+    }
+
+    /**
+     * Creates an empty decoder pane
+     */
+    public static DecoderPane getDefaultPane()
+    {
+        return new DecoderPane();
+    }
+
+    /**
+     * Indicates if the decoder type is supported by this factory
+     */
+    public static boolean isSupported(DecoderType decoderType)
+    {
+        return SUPPORTED_DECODER_TYPES.contains(decoderType);
+    }
+}

src/main/java/io/github/dsheirer/instrument/gui/viewer/decoder/P25Phase1Pane.java

@@ -0,0 +1,195 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.instrument.gui.viewer.decoder;
+
+import io.github.dsheirer.instrument.gui.viewer.chart.ComplexSampleLineChart;
+import io.github.dsheirer.instrument.gui.viewer.chart.DoubleLineChart;
+import io.github.dsheirer.instrument.gui.viewer.chart.EyeDiagramChart;
+import io.github.dsheirer.instrument.gui.viewer.chart.PhaseLineChart;
+import io.github.dsheirer.instrument.gui.viewer.chart.SymbolChart;
+import io.github.dsheirer.message.Message;
+import io.github.dsheirer.module.decode.DecoderType;
+import io.github.dsheirer.module.decode.p25.P25_C4FMDecoderInstrumented;
+import io.github.dsheirer.sample.Broadcaster;
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
+import javafx.scene.layout.HBox;
+import javafx.scene.layout.Priority;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class P25Phase1Pane extends DecoderPane
+{
+    private final static Logger mLog = LoggerFactory.getLogger(P25Phase1Pane.class);
+
+    private HBox mSampleChartBox;
+    private ComplexSampleLineChart mSampleLineChart;
+    private EyeDiagramChart mEyeDiagramChart;
+    private HBox mDecoderChartBox;
+    private SymbolChart mSymbolChart;
+    private PhaseLineChart mPLLPhaseErrorLineChart;
+    private DoubleLineChart mPLLFrequencyLineChart;
+    private DoubleLineChart mSamplesPerSymbolLineChart;
+    private Broadcaster<ComplexBuffer> mFilteredBufferBroadcaster = new Broadcaster<>();
+    private P25_C4FMDecoderInstrumented mDecoder = new P25_C4FMDecoderInstrumented(null);
+
+    public P25Phase1Pane()
+    {
+        super(DecoderType.P25_PHASE1);
+        init();
+    }
+
+    private void init()
+    {
+        addListener(getDecoder());
+
+        getDecoder().setFilteredBufferListener(mFilteredBufferBroadcaster);
+        getDecoder().setSymbolListener(getSymbolChart());
+        getDecoder().setPLLPhaseErrorListener(getPLLPhaseErrorLineChart());
+        getDecoder().setPLLFrequencyListener(getPLLFrequencyLineChart());
+        getDecoder().setSymbolDecisionDataListener(getEyeDiagramChart());
+        getDecoder().setSamplesPerSymbolListener(getSamplesPerSymbolLineChart());
+        mFilteredBufferBroadcaster.addListener(getSampleLineChart());
+
+        HBox.setHgrow(getSampleChartBox(), Priority.ALWAYS);
+        HBox.setHgrow(getDecoderChartBox(), Priority.ALWAYS);
+        getChildren().addAll(getSampleChartBox(), getDecoderChartBox());
+
+        mDecoder.setMessageListener(new Listener<Message>()
+        {
+            @Override
+            public void receive(Message message)
+            {
+                mLog.debug(message.getMessage());
+            }
+        });
+
+    }
+
+    @Override
+    public void setSampleRate(double sampleRate)
+    {
+        mLog.debug("Configuring for sample rate: " + sampleRate);
+
+        mDecoder.setSampleRate(sampleRate);
+        double samplesPerSymbol = sampleRate / 4800.0;
+
+        getSampleLineChart().setSamplesPerSymbol((int)samplesPerSymbol);
+    }
+
+    private P25_C4FMDecoderInstrumented getDecoder()
+    {
+        return mDecoder;
+    }
+
+    private SymbolChart getSymbolChart()
+    {
+        if(mSymbolChart == null)
+        {
+            mSymbolChart = new SymbolChart(10);
+        }
+
+        return mSymbolChart;
+    }
+
+    private HBox getDecoderChartBox()
+    {
+        if(mDecoderChartBox == null)
+        {
+            mDecoderChartBox = new HBox();
+            mDecoderChartBox.setMaxHeight(Double.MAX_VALUE);
+            getSymbolChart().setMaxWidth(Double.MAX_VALUE);
+            getPLLPhaseErrorLineChart().setMaxWidth(Double.MAX_VALUE);
+            getPLLFrequencyLineChart().setMaxWidth(Double.MAX_VALUE);
+            HBox.setHgrow(getSymbolChart(), Priority.ALWAYS);
+            HBox.setHgrow(getPLLPhaseErrorLineChart(), Priority.ALWAYS);
+            HBox.setHgrow(getPLLFrequencyLineChart(), Priority.ALWAYS);
+            mDecoderChartBox.getChildren().addAll(getSymbolChart(), getPLLPhaseErrorLineChart(),
+                getPLLFrequencyLineChart());
+        }
+
+        return mDecoderChartBox;
+    }
+
+    private HBox getSampleChartBox()
+    {
+        if(mSampleChartBox == null)
+        {
+            mSampleChartBox = new HBox();
+            mSampleChartBox.setMaxHeight(Double.MAX_VALUE);
+            getSampleLineChart().setMaxWidth(Double.MAX_VALUE);
+            getEyeDiagramChart().setMaxWidth(Double.MAX_VALUE);
+            getSamplesPerSymbolLineChart().setMaxWidth(Double.MAX_VALUE);
+            HBox.setHgrow(getSampleLineChart(), Priority.ALWAYS);
+            HBox.setHgrow(getEyeDiagramChart(), Priority.ALWAYS);
+            HBox.setHgrow(getSamplesPerSymbolLineChart(), Priority.ALWAYS);
+            mSampleChartBox.getChildren().addAll(getSampleLineChart(), getEyeDiagramChart(),
+                getSamplesPerSymbolLineChart());
+        }
+
+        return mSampleChartBox;
+    }
+
+    private ComplexSampleLineChart getSampleLineChart()
+    {
+        if(mSampleLineChart == null)
+        {
+            mSampleLineChart = new ComplexSampleLineChart(100, 10);
+        }
+
+        return mSampleLineChart;
+    }
+
+    private EyeDiagramChart getEyeDiagramChart()
+    {
+        if(mEyeDiagramChart == null)
+        {
+            mEyeDiagramChart = new EyeDiagramChart(10);
+        }
+
+        return mEyeDiagramChart;
+    }
+
+    private PhaseLineChart getPLLPhaseErrorLineChart()
+    {
+        if(mPLLPhaseErrorLineChart == null)
+        {
+            mPLLPhaseErrorLineChart = new PhaseLineChart(40);
+        }
+
+        return mPLLPhaseErrorLineChart;
+    }
+
+    private DoubleLineChart getPLLFrequencyLineChart()
+    {
+        if(mPLLFrequencyLineChart == null)
+        {
+            mPLLFrequencyLineChart = new DoubleLineChart( "PLL Frequency", -500, 500, 50, 40);
+        }
+
+        return mPLLFrequencyLineChart;
+    }
+
+    private DoubleLineChart getSamplesPerSymbolLineChart()
+    {
+        if(mSamplesPerSymbolLineChart == null)
+        {
+            mSamplesPerSymbolLineChart = new DoubleLineChart( "Sample Point", 9.5, 11.5, 0.1, 40);
+        }
+
+        return mSamplesPerSymbolLineChart;
+    }
+}

src/main/java/io/github/dsheirer/module/decode/Decoder.java

@@ -22,39 +22,39 @@ import io.github.dsheirer.message.Message;
 import io.github.dsheirer.module.Module;
 import io.github.dsheirer.sample.Listener;
 
-public abstract class Decoder extends Module
+public abstract class Decoder extends Module implements IMessageProvider
-							  implements IMessageProvider, Listener<Message>
 {
-	/* This has to be a broadcaster in order for references to persist */
+    /* This has to be a broadcaster in order for references to persist */
-	protected Listener<Message> mMessageListener;
+    private Listener<Message> mMessageDistributor = new MessageDistributor();
+    protected Listener<Message> mMessageListener;
 
-	/**
+    /**
-	 * Decoder - parent class for all decoders, demodulators and components.  
+     * Decoder - parent class for all decoders, demodulators and components.
-	 */
+     */
-	public Decoder()
+    public Decoder()
-	{
+    {
-	}
+    }
 
-	@Override
+    @Override
-	public void dispose()
+    public void dispose()
-	{
+    {
-		mMessageListener = null;
+        mMessageListener = null;
-	}
+    }
 
-	/**
+    /**
-	 * Identifies the decoder type (ie protocol) 
+     * Identifies the decoder type (ie protocol)
-	 */
+     */
-	public abstract DecoderType getDecoderType();
+    public abstract DecoderType getDecoderType();
 
 
     /**
      * Adds a listener for receiving decoded messages from this decoder
      */
     @Override
-    public void setMessageListener( Listener<Message> listener )
+    public void setMessageListener(Listener<Message> listener)
     {
-    	mMessageListener = listener;
+        mMessageListener = listener;
-	}
+    }
 
     /**
      * Removes the listener from receiving decoded messages from all attached
@@ -63,23 +63,29 @@ public abstract class Decoder extends Module
     @Override
     public void removeMessageListener()
     {
-    	mMessageListener = null;
+        mMessageListener = null;
     }
 
     /**
-     * Broadcasts the message to the registered message listener
+     * Message listener for receiving the output from this decoder
      */
-    public void broadcast( Message message )
+    protected Listener<Message> getMessageListener()
     {
-    	if( mMessageListener != null )
+        return mMessageDistributor;
-    	{
-    		mMessageListener.receive( message );
-    	}
     }
 
-	@Override
+    /**
-	public void receive( Message message )
+     * Distributes/forwards messages from sub-class decoder implementations to the registered message listener.
-	{
+     */
-		broadcast( message );
+    public class MessageDistributor implements Listener<Message>
-	}
+    {
+        @Override
+        public void receive(Message message)
+        {
+            if(mMessageListener != null)
+            {
+                mMessageListener.receive(message);
+            }
+        }
+    }
 }

src/main/java/io/github/dsheirer/module/decode/DecoderFactory.java

@@ -246,9 +246,7 @@ public class DecoderFactory
                 switch(modulation)
                 {
                     case C4FM:
-                        modules.add(new FMDemodulatorModule(P25_C4FM_IQ_FILTER));
+                        modules.add(new P25_C4FMDecoder(aliasList));
-                        modules.add(new DemodulatedAudioFilterModule(P25_C4FM_DEMOD_FILTER, 1.0f));
-                        modules.add(new P25_C4FMDecoder(aliasList, decodeConfig.getAFCMaximumCorrection()));
                         modules.add(new P25DecoderState(aliasList, channelType, P25Decoder.Modulation.C4FM,
                             p25Config.getIgnoreDataCalls()));
                         break;

src/main/java/io/github/dsheirer/module/decode/fleetsync2/Fleetsync2Decoder.java

@@ -90,7 +90,7 @@ public class Fleetsync2Decoder extends Decoder implements IFilteredRealBufferLis
         mMessageProcessor = new Fleetsync2MessageProcessor( aliasList );
         mMessageFramer.addMessageListener( mMessageProcessor );
         
-        mMessageProcessor.setMessageListener( this );
+        mMessageProcessor.setMessageListener( getMessageListener() );
 	}
     
     public void dispose()

src/main/java/io/github/dsheirer/module/decode/lj1200/LJ1200Decoder.java

@@ -100,7 +100,7 @@ public class LJ1200Decoder extends Decoder implements IFilteredRealBufferListene
         mMessageProcessor = new LJ1200MessageProcessor( aliasList );
         mTowerMessageFramer.addMessageListener( mMessageProcessor );
         mTransponderMessageFramer.addMessageListener( mMessageProcessor );
-        mMessageProcessor.setMessageListener( this );
+        mMessageProcessor.setMessageListener( getMessageListener() );
 	}
     
 	@Override

src/main/java/io/github/dsheirer/module/decode/ltrnet/LTRNetDecoder.java

@@ -74,7 +74,7 @@ public class LTRNetDecoder extends Decoder
 		
 		mLTRMessageFramer.addMessageListener( mLTRMessageProcessor );
 		
-		mLTRMessageProcessor.setMessageListener( this );
+		mLTRMessageProcessor.setMessageListener( getMessageListener() );
 	}
 
 	@Override

src/main/java/io/github/dsheirer/module/decode/ltrstandard/LTRStandardDecoder.java

@@ -64,7 +64,7 @@ public class LTRStandardDecoder extends Decoder implements IUnFilteredRealBuffer
 
 		mLTRMessageProcessor = new LTRStandardMessageProcessor( direction, aliasList );
 		mLTRMessageFramer.addMessageListener( mLTRMessageProcessor );
-		mLTRMessageProcessor.setMessageListener( this );
+		mLTRMessageProcessor.setMessageListener( getMessageListener() );
 	}
 
 	@Override

src/main/java/io/github/dsheirer/module/decode/mdc1200/MDCDecoder.java

@@ -102,7 +102,7 @@ public class MDCDecoder extends Decoder implements IFilteredRealBufferListener,
         /* Message Processor */
         mMessageProcessor = new MDCMessageProcessor( aliasList );
         mMessageFramer.addMessageListener( mMessageProcessor );
-        mMessageProcessor.addMessageListener( this );
+        mMessageProcessor.addMessageListener(getMessageListener());
 	}
     
     public void dispose()

src/main/java/io/github/dsheirer/module/decode/mpt1327/MPT1327Decoder.java

@@ -148,7 +148,7 @@ public class MPT1327Decoder extends Decoder implements IFilteredRealBufferListen
 
         /* Fully decoded and framed messages processor */
         mMessageProcessor = new MPT1327MessageProcessor(aliasList);
-        mMessageProcessor.setMessageListener(this);
+        mMessageProcessor.setMessageListener(getMessageListener());
         mControlMessageFramer.addMessageListener(mMessageProcessor);
         mTrafficMessageFramer.addMessageListener(mMessageProcessor);
     }

src/main/java/io/github/dsheirer/module/decode/p25/P25Decoder.java

@@ -1,70 +1,91 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.module.decode.p25;
 
 import io.github.dsheirer.alias.AliasList;
-import io.github.dsheirer.instrument.Instrumentable;
 import io.github.dsheirer.module.decode.Decoder;
 import io.github.dsheirer.module.decode.DecoderType;
 import io.github.dsheirer.source.tuner.frequency.IFrequencyChangeListener;
 import io.github.dsheirer.source.tuner.frequency.IFrequencyChangeProvider;
 
-public abstract class P25Decoder extends Decoder implements IFrequencyChangeListener, IFrequencyChangeProvider, Instrumentable
+public abstract class P25Decoder extends Decoder implements IFrequencyChangeListener, IFrequencyChangeProvider
 {
-	private P25MessageProcessor mMessageProcessor;
+    private P25MessageProcessor mMessageProcessor;
+    private AliasList mAliasList;
 
-	public P25Decoder( AliasList aliasList )
+    public P25Decoder(AliasList aliasList)
-	{
-        mMessageProcessor = new P25MessageProcessor( aliasList );
-        mMessageProcessor.setMessageListener( this );
-	}
-	
-	public void dispose()
-	{
-		super.dispose();
-		
-		mMessageProcessor.dispose();
-		mMessageProcessor = null;
-	}
-
-	@Override
-    public DecoderType getDecoderType()
     {
-	    return DecoderType.P25_PHASE1;
+        mAliasList = aliasList;
+        mMessageProcessor = new P25MessageProcessor(mAliasList);
+        mMessageProcessor.setMessageListener(getMessageListener());
     }
 
-	protected P25MessageProcessor getMessageProcessor()
+    protected AliasList getAliasList()
-	{
+    {
-		return mMessageProcessor;
+        return mAliasList;
-	}
+    }
 
-	public abstract Modulation getModulation();
+    public void dispose()
+    {
+        super.dispose();
 
-	public enum Modulation
+        mMessageProcessor.dispose();
-	{ 
+        mMessageProcessor = null;
-		CQPSK( "Simulcast (LSM)", "LSM" ),
+    }
-		C4FM( "Normal (C4FM)", "C4FM" );
 
-		private String mLabel;
+    @Override
-		private String mShortLabel;
+    public DecoderType getDecoderType()
+    {
+        return DecoderType.P25_PHASE1;
+    }
 
-		private Modulation( String label, String shortLabel )
+    protected P25MessageProcessor getMessageProcessor()
-		{
+    {
-			mLabel = label;
+        return mMessageProcessor;
-			mShortLabel = shortLabel;
+    }
-		}
 
-		public String getLabel()
+    public abstract Modulation getModulation();
-		{
-			return mLabel;
-		}
 
-		public String getShortLabel()
+    public enum Modulation
-		{
+    {
-			return mShortLabel;
+        CQPSK("Simulcast (LSM)", "LSM"),
-		}
+        C4FM("Normal (C4FM)", "C4FM");
 
-		public String toString()
+        private String mLabel;
-		{
+        private String mShortLabel;
-			return getLabel();
+
-		}
+        private Modulation(String label, String shortLabel)
-	}
+        {
+            mLabel = label;
+            mShortLabel = shortLabel;
+        }
+
+        public String getLabel()
+        {
+            return mLabel;
+        }
+
+        public String getShortLabel()
+        {
+            return mShortLabel;
+        }
+
+        public String toString()
+        {
+            return getLabel();
+        }
+    }
 }

src/main/java/io/github/dsheirer/module/decode/p25/P25_C4FMDecoder.java

@@ -1,244 +1,200 @@
 /*******************************************************************************
- * sdrtrunk
+ * sdr-trunk
- * Copyright (C) 2014-2017 Dennis Sheirer
+ * Copyright (C) 2014-2018 Dennis Sheirer
  *
- * This program is free software: you can redistribute it and/or modify
+ * This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public
- * it under the terms of the GNU General Public License as published by
+ * License as published by  the Free Software Foundation, either version 3 of the License, or  (at your option) any
- * the Free Software Foundation, either version 3 of the License, or
+ * later version.
- * (at your option) any later version.
  *
- * This program is distributed in the hope that it will be useful,
+ * This program is distributed in the hope that it will be useful,  but WITHOUT ANY WARRANTY; without even the implied
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * warranty of  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
- * 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
+ * You should have received a copy of the GNU General Public License  along with this program.
- * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ * If not, see <http://www.gnu.org/licenses/>
  *
  ******************************************************************************/
 package io.github.dsheirer.module.decode.p25;
 
 import io.github.dsheirer.alias.AliasList;
-import io.github.dsheirer.instrument.tap.Tap;
+import io.github.dsheirer.dsp.filter.FilterFactory;
-import io.github.dsheirer.instrument.tap.TapGroup;
+import io.github.dsheirer.dsp.filter.design.FilterDesignException;
-import io.github.dsheirer.instrument.tap.stream.DibitTap;
+import io.github.dsheirer.dsp.filter.fir.FIRFilterSpecification;
-import io.github.dsheirer.instrument.tap.stream.FloatTap;
+import io.github.dsheirer.dsp.filter.fir.complex.ComplexFIRFilter;
+import io.github.dsheirer.dsp.psk.DQPSKDemodulator;
+import io.github.dsheirer.dsp.psk.InterpolatingSampleBuffer;
+import io.github.dsheirer.dsp.psk.InterpolatingSampleBufferInstrumented;
+import io.github.dsheirer.dsp.psk.pll.CostasLoop;
 import io.github.dsheirer.sample.Listener;
-import io.github.dsheirer.sample.real.IFilteredRealBufferListener;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
-import io.github.dsheirer.sample.real.RealBuffer;
+import io.github.dsheirer.sample.complex.IComplexBufferListener;
 import io.github.dsheirer.source.tuner.frequency.FrequencyChangeEvent;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.ArrayList;
+import java.util.HashMap;
-import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ScheduledExecutorService;
 
-public class P25_C4FMDecoder extends P25Decoder implements IFilteredRealBufferListener
+public class P25_C4FMDecoder extends P25Decoder implements IComplexBufferListener, Listener<ComplexBuffer>
 {
-	private final static Logger mLog = LoggerFactory.getLogger( P25_C4FMDecoder.class );
+    private final static Logger mLog = LoggerFactory.getLogger(P25_C4FMDecoder.class);
+    protected static final double SYMBOL_RATE = 4800;
+    protected InterpolatingSampleBuffer mInterpolatingSampleBuffer;
+    protected DQPSKDemodulator mQPSKDemodulator;
+    protected CostasLoop mCostasLoop;
+    protected P25MessageFramer mMessageFramer;
+    protected double mSampleRate;
+    private Map<Double,float[]> mBasebandFilters = new HashMap<>();
+    private ComplexFIRFilter mBasebandFilter;
 
-    /* Instrumentation Taps */
+    public P25_C4FMDecoder(AliasList aliasList)
-	private static final String INSTRUMENT_C4FM_SYMBOL_FILTER_OUTPUT = "Tap Point: Symbol Filter Output";
-	private static final String INSTRUMENT_C4FM_SLICER_OUTPUT = "Tap Point: C4FM Slicer Output";
-
-	private List<TapGroup> mAvailableTaps;
-	private C4FMSymbolFilter mSymbolFilter;
-	private C4FMSlicer mC4FMSlicer;
-	private P25MessageFramer mMessageFramer;
-	
-	/**
-	 * P25 Phase 1 C4FM Decoder processes real buffers of un-filtered, 
-	 * demodulated audio and produces decoded P25 Phase 1 Messages.
-	 * 
-	 * Provides Frequency Control to steer external tuner source and incorporates
-	 * internal gain control.
-	 * 
-	 * Note: use the P25AudioModule to convert the decoded messages into audio.
-	 * 
-	 * @param aliasList - optional (can be null) list of alias values for network
-	 * infrastructure and subscriber identities that will be included in each
-	 * decoded message
-	 */
-	public P25_C4FMDecoder(AliasList aliasList, int frequencyCorrectionMaximum )
-	{
-		super( aliasList );
-		
-		/* Shape gain and frequency offsets to optimize sample stream */
-		mSymbolFilter = new C4FMSymbolFilter( frequencyCorrectionMaximum );
-
-		/* Convert samples to symbols */
-		mC4FMSlicer = new C4FMSlicer();
-		mSymbolFilter.setListener( mC4FMSlicer );
-
-		/* Sync pattern detection and message construction */
-		mMessageFramer = new P25MessageFramer( aliasList );
-        mC4FMSlicer.addListener( mMessageFramer );
-        
-        /* Process and broadcast messages */
-        mMessageFramer.setListener( getMessageProcessor() );
-	}
-
-	@Override
-	public void dispose()
-	{
-		super.dispose();
-		
-		mSymbolFilter.dispose();
-		mSymbolFilter = null;
-		
-		mMessageFramer.dispose();
-		mMessageFramer = null;
-
-		mC4FMSlicer.dispose();
-		mC4FMSlicer = null;
-	}
-	
-	public Modulation getModulation()
-	{
-		return Modulation.C4FM;
-	}
-	
-	@Override
-	public Listener<RealBuffer> getFilteredRealBufferListener()
-	{
-		return mSymbolFilter;
-	}
-	
-	/**
-	 * Instrumentation taps for monitoring internal processing
-	 */
-	@Override
-    public List<TapGroup> getTapGroups()
     {
-		if( mAvailableTaps == null )
+        super(aliasList);
-		{
+        setSampleRate(48000.0);
-			mAvailableTaps = new ArrayList<>();
-
-			TapGroup group = new TapGroup( "P25 C4FM Decoder" );
-			
-			group.add( new FloatTap( INSTRUMENT_C4FM_SYMBOL_FILTER_OUTPUT, 0, 0.1f ) );
-			group.add( new DibitTap( INSTRUMENT_C4FM_SLICER_OUTPUT, 0, 0.1f ) );
-
-			mAvailableTaps.add( group );
-			
-			if( mSymbolFilter != null )
-			{
-				mAvailableTaps.addAll( mSymbolFilter.getTapGroups() );
-			}
-		}
-		
-		return mAvailableTaps;
     }
 
-	/**
+    public void setSampleRate(double sampleRate)
-	 * Adds an instrumentation tap to monitor internal processing.  
-	 */
-	@Override
-    public void registerTap( Tap tap )
     {
-		if( mSymbolFilter != null )
+        if(sampleRate <= SYMBOL_RATE * 2)
-		{
+        {
-			mSymbolFilter.registerTap( tap );
+            throw new IllegalArgumentException("Sample rate must be at least twice the symbol rate [4800]");
-		}
+        }
 
-		switch( tap.getName() )
+        mSampleRate = sampleRate;
-		{
+        mBasebandFilter = new ComplexFIRFilter(getBasebandFilter(), 1.0f);
-			case INSTRUMENT_C4FM_SYMBOL_FILTER_OUTPUT:
-				FloatTap symbolTap = (FloatTap)tap;
-				mSymbolFilter.setListener( symbolTap );
-				symbolTap.setListener( mC4FMSlicer );
-				break;
-			case INSTRUMENT_C4FM_SLICER_OUTPUT:
-				DibitTap slicerTap = (DibitTap)tap;
 
-				if( mC4FMSlicer != null )
+        mCostasLoop = new CostasLoop(mSampleRate, SYMBOL_RATE);
-				{
+
-					mC4FMSlicer.addListener( slicerTap );
+        mInterpolatingSampleBuffer = new InterpolatingSampleBufferInstrumented((float)(sampleRate / SYMBOL_RATE));
-				}
+        mQPSKDemodulator = new DQPSKDemodulator(mCostasLoop, mInterpolatingSampleBuffer);
-				break;
+
-			default:
+        //Message framer can trigger a symbol-inversion correction to the PLL when detected
-				break;
+        mMessageFramer = new P25MessageFramer(getAliasList(), mCostasLoop);
-		}
+        mMessageFramer.setListener(getMessageProcessor());
+        mQPSKDemodulator.setDibitListener(mMessageFramer);
     }
 
-	/**
+    @Override
-	 * Removes the instrumentation tap.
+    public void receive(ComplexBuffer complexBuffer)
-	 */
-	@Override
-    public void unregisterTap( Tap tap )
     {
-		if( mSymbolFilter != null )
+        ComplexBuffer filtered = filter(complexBuffer);
-		{
+        mQPSKDemodulator.receive(filtered);
-			mSymbolFilter.unregisterTap( tap );
-		}
-		
-		switch( tap.getName() )
-		{
-			case INSTRUMENT_C4FM_SYMBOL_FILTER_OUTPUT:
-				mSymbolFilter.setListener( mC4FMSlicer );
-				break;
-			case INSTRUMENT_C4FM_SLICER_OUTPUT:
-				DibitTap slicerTap = (DibitTap)tap;
-				
-				if( mC4FMSlicer != null )
-				{
-					mC4FMSlicer.removeListener( slicerTap );
-				}
-				break;
-			default:
-				throw new IllegalArgumentException( "Unrecognized tap: " + 
-							tap.getName() );
-		}
     }
 
-	@Override
+    protected ComplexBuffer filter(ComplexBuffer complexBuffer)
-	public void reset()
+    {
-	{
+        return mBasebandFilter.filter(complexBuffer);
-		// TODO Auto-generated method stub
+    }
 
-	}
+    private double getSampleRate()
+    {
+        return mSampleRate;
+    }
 
-	@Override
+    private float[] getBasebandFilter()
-	public void start( ScheduledExecutorService executor )
+    {
-	{
+        float[] filter = mBasebandFilters.get(getSampleRate());
-		// TODO Auto-generated method stub
 
-	}
+        if(filter == null)
+        {
+            FIRFilterSpecification specification = FIRFilterSpecification.lowPassBuilder()
+                .sampleRate((int)getSampleRate())
+                .passBandCutoff(5100)
+                .passBandAmplitude(1.0)
+                .passBandRipple(0.01)
+                .stopBandAmplitude(0.0)
+                .stopBandStart(6500)
+                .stopBandRipple(0.01)
+                .build();
 
-	@Override
+            try
-	public void stop()
+            {
-	{
+                filter = FilterFactory.getTaps(specification);
-		// TODO Auto-generated method stub
 
-	}
+            }
+            catch(FilterDesignException fde)
+            {
+                mLog.error("Couldn't design low pass baseband filter for sample rate: " + getSampleRate());
+            }
+            if(filter != null)
+            {
+                mBasebandFilters.put(getSampleRate(), filter);
+            }
+            else
+            {
+                throw new IllegalStateException("Couldn't design a C4FM symbol filter for sample rate: " + mSampleRate);
+            }
+        }
 
-	@Override
+        return filter;
-	public void setFrequencyChangeListener(	Listener<FrequencyChangeEvent> listener )
+    }
-	{
-		if( mSymbolFilter != null )
-		{
-			mSymbolFilter.setFrequencyChangeListener( listener );
-		}
-	}
 
-	@Override
+    public void dispose()
-	public void removeFrequencyChangeListener()
+    {
-	{
+        super.dispose();
-		if( mSymbolFilter != null )
-		{
-			mSymbolFilter.setFrequencyChangeListener( null );
-		}
-	}
 
-	@Override
+        mBasebandFilter.dispose();
-	public Listener<FrequencyChangeEvent> getFrequencyChangeListener()
+        mBasebandFilter = null;
-	{
-		if( mSymbolFilter != null )
-		{
-			return mSymbolFilter.getFrequencyChangeListener();
-		}
 
-		return null;
+        mMessageFramer.dispose();
-	}
+        mMessageFramer = null;
+    }
+
+    @Override
+    public void setFrequencyChangeListener(Listener<FrequencyChangeEvent> listener)
+    {
+    }
+
+    @Override
+    public void removeFrequencyChangeListener()
+    {
+    }
+
+    @Override
+    public Listener<FrequencyChangeEvent> getFrequencyChangeListener()
+    {
+        return new Listener<FrequencyChangeEvent>()
+        {
+            @Override
+            public void receive(FrequencyChangeEvent frequencyChangeEvent)
+            {
+                switch(frequencyChangeEvent.getEvent())
+                {
+                    case NOTIFICATION_FREQUENCY_CHANGE:
+                    case NOTIFICATION_FREQUENCY_CORRECTION_CHANGE:
+                    case NOTIFICATION_CHANNEL_FREQUENCY_CORRECTION_CHANGE:
+                    case NOTIFICATION_SAMPLE_RATE_CHANGE:
+                        mCostasLoop.reset();
+                        break;
+                }
+            }
+        };
+    }
+
+    @Override
+    public Listener<ComplexBuffer> getComplexBufferListener()
+    {
+        return P25_C4FMDecoder.this;
+    }
+
+    public Modulation getModulation()
+    {
+        return Modulation.C4FM;
+    }
+
+    @Override
+    public void reset()
+    {
+        mCostasLoop.reset();
+    }
+
+    @Override
+    public void start(ScheduledExecutorService executor)
+    {
+    }
+
+    @Override
+    public void stop()
+    {
+    }
 }

src/main/java/io/github/dsheirer/module/decode/p25/P25_C4FMDecoderInstrumented.java

@@ -0,0 +1,109 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.module.decode.p25;
+
+import io.github.dsheirer.alias.AliasList;
+import io.github.dsheirer.dsp.psk.DQPSKDemodulatorInstrumented;
+import io.github.dsheirer.dsp.psk.InterpolatingSampleBufferInstrumented;
+import io.github.dsheirer.dsp.psk.SymbolDecisionData;
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.sample.complex.Complex;
+import io.github.dsheirer.sample.complex.ComplexBuffer;
+
+public class P25_C4FMDecoderInstrumented extends P25_C4FMDecoder
+{
+    private Listener<Double> mPLLPhaseErrorListener;
+    private Listener<Double> mPLLFrequencyListener;
+    private Listener<Double> mSamplesPerSymbolListener;
+    private Listener<Complex> mSymbolListener;
+    private Listener<ComplexBuffer> mFilteredSymbolListener;
+    private Listener<SymbolDecisionData> mSymbolDecisionDataListener;
+
+    public P25_C4FMDecoderInstrumented(AliasList aliasList)
+    {
+        super(aliasList);
+    }
+
+    /**
+     * Overrides the filter method so that we can capture the filtered samples for instrumentation
+     */
+    protected ComplexBuffer filter(ComplexBuffer complexBuffer)
+    {
+        ComplexBuffer filtered = super.filter(complexBuffer);
+
+        if(mFilteredSymbolListener != null)
+        {
+            mFilteredSymbolListener.receive(filtered);
+        }
+
+        return filtered;
+    }
+
+    /**
+     * Overrides this method so we can correctly configure for instrumented operations
+     */
+    public void setSampleRate(double sampleRate)
+    {
+        super.setSampleRate(sampleRate);
+        InterpolatingSampleBufferInstrumented instrumentedBuffer = new InterpolatingSampleBufferInstrumented((float)(sampleRate / SYMBOL_RATE));
+        mInterpolatingSampleBuffer = instrumentedBuffer;
+
+        DQPSKDemodulatorInstrumented instrumented = new DQPSKDemodulatorInstrumented(mCostasLoop, instrumentedBuffer, mSampleRate);
+        mQPSKDemodulator = instrumented;
+
+        instrumented.setSymbolListener(mSymbolListener);
+        instrumented.setPLLErrorListener(mPLLPhaseErrorListener);
+        instrumented.setPLLFrequencyListener(mPLLFrequencyListener);
+        instrumented.setSymbolDecisionDataListener(mSymbolDecisionDataListener);
+        instrumented.setSamplesPerSymbolListener(mSamplesPerSymbolListener);
+        instrumented.setDibitListener(mMessageFramer);
+    }
+
+    public void setSymbolListener(Listener<Complex> listener)
+    {
+        mSymbolListener = listener;
+        ((DQPSKDemodulatorInstrumented)mQPSKDemodulator).setSymbolListener(listener);
+    }
+
+    public void setPLLPhaseErrorListener(Listener<Double> listener)
+    {
+        mPLLPhaseErrorListener = listener;
+        ((DQPSKDemodulatorInstrumented)mQPSKDemodulator).setPLLErrorListener(listener);
+    }
+
+    public void setPLLFrequencyListener(Listener<Double> listener)
+    {
+        mPLLFrequencyListener = listener;
+        ((DQPSKDemodulatorInstrumented)mQPSKDemodulator).setPLLFrequencyListener(listener);
+    }
+
+    public void setFilteredBufferListener(Listener<ComplexBuffer> listener)
+    {
+        mFilteredSymbolListener = listener;
+    }
+
+    public void setSymbolDecisionDataListener(Listener<SymbolDecisionData> listener)
+    {
+        mSymbolDecisionDataListener = listener;
+        ((DQPSKDemodulatorInstrumented)mQPSKDemodulator).setSymbolDecisionDataListener(listener);
+    }
+
+    public void setSamplesPerSymbolListener(Listener<Double> listener)
+    {
+        mSamplesPerSymbolListener = listener;
+        ((DQPSKDemodulatorInstrumented)mQPSKDemodulator).setSamplesPerSymbolListener(listener);
+    }
+}

src/main/java/io/github/dsheirer/module/decode/p25/P25_LSMDecoder.java

@@ -23,13 +23,8 @@ import io.github.dsheirer.dsp.filter.Window.WindowType;
 import io.github.dsheirer.dsp.filter.fir.complex.ComplexFIRFilter_CB_CB;
 import io.github.dsheirer.dsp.gain.ComplexFeedForwardGainControl;
 import io.github.dsheirer.dsp.psk.LSMDemodulator;
-import io.github.dsheirer.dsp.psk.QPSKPolarSlicer;
+import io.github.dsheirer.dsp.psk.QPSKSymbolDecoder;
-import io.github.dsheirer.instrument.tap.Tap;
 import io.github.dsheirer.instrument.tap.TapGroup;
-import io.github.dsheirer.instrument.tap.stream.ComplexSampleTap;
-import io.github.dsheirer.instrument.tap.stream.ComplexTap;
-import io.github.dsheirer.instrument.tap.stream.DibitTap;
-import io.github.dsheirer.instrument.tap.stream.QPSKTap;
 import io.github.dsheirer.sample.Listener;
 import io.github.dsheirer.sample.complex.ComplexBuffer;
 import io.github.dsheirer.sample.complex.ComplexBufferToStreamConverter;
@@ -38,73 +33,72 @@ import io.github.dsheirer.source.tuner.frequency.FrequencyChangeEvent;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.ScheduledExecutorService;
 
 public class P25_LSMDecoder extends P25Decoder implements IComplexBufferListener
 {
-	private final static Logger mLog = LoggerFactory.getLogger( P25_LSMDecoder.class );
+    private final static Logger mLog = LoggerFactory.getLogger(P25_LSMDecoder.class);
 
     /* Instrumentation Taps */
-	private static final String INSTRUMENT_BASEBAND_FILTER_OUTPUT = "Tap Point: Baseband Filter Output";
+    private static final String INSTRUMENT_BASEBAND_FILTER_OUTPUT = "Tap Point: Baseband Filter Output";
-	private static final String INSTRUMENT_AGC_OUTPUT = "Tap Point: AGC Output";
+    private static final String INSTRUMENT_AGC_OUTPUT = "Tap Point: AGC Output";
-	private static final String INSTRUMENT_LSM_DEMODULATOR_OUTPUT = "Tap Point: LSM Demodulator Output";
+    private static final String INSTRUMENT_LSM_DEMODULATOR_OUTPUT = "Tap Point: LSM Demodulator Output";
-	private static final String INSTRUMENT_QPSK_SLICER_OUTPUT = "Tap Point: QPSK Slicer Output";
+    private static final String INSTRUMENT_QPSK_SLICER_OUTPUT = "Tap Point: QPSK Slicer Output";
 
-	private List<TapGroup> mAvailableTaps;
+    private List<TapGroup> mAvailableTaps;
 
-	private ComplexFIRFilter_CB_CB mBasebandFilter;
+    private ComplexFIRFilter_CB_CB mBasebandFilter;
-	private ComplexBufferToStreamConverter mStreamConverter = new ComplexBufferToStreamConverter();
+    private ComplexBufferToStreamConverter mStreamConverter = new ComplexBufferToStreamConverter();
-	private ComplexFeedForwardGainControl mAGC = 
+    private ComplexFeedForwardGainControl mAGC =
-							new ComplexFeedForwardGainControl( 32 );
+        new ComplexFeedForwardGainControl(32);
-	private LSMDemodulator mLSMDemodulator = new LSMDemodulator();
+    private LSMDemodulator mLSMDemodulator = new LSMDemodulator();
-	private QPSKPolarSlicer mQPSKSlicer = new QPSKPolarSlicer();
+    private QPSKSymbolDecoder mQPSKSlicer = new QPSKSymbolDecoder();
-	private P25MessageFramer mMessageFramer;
+    private P25MessageFramer mMessageFramer;
 
-	public P25_LSMDecoder( AliasList aliasList )
+    public P25_LSMDecoder(AliasList aliasList)
-	{
+    {
-		super( aliasList );
+        super(aliasList);
 
-		mBasebandFilter = new ComplexFIRFilter_CB_CB( FilterFactory.getLowPass( 
+        mBasebandFilter = new ComplexFIRFilter_CB_CB(FilterFactory.getLowPass(
-				48000, 7250, 8000, 60, WindowType.HANNING, true ), 1.0f );
+            48000, 7250, 8000, 60, WindowType.HANNING, true), 1.0f);
 
-		mBasebandFilter.setListener( mStreamConverter );
+        mBasebandFilter.setListener(mStreamConverter);
 
-		mStreamConverter.setListener( mAGC );
+        mStreamConverter.setListener(mAGC);
 
-		mAGC.setListener( mLSMDemodulator );
+        mAGC.setListener(mLSMDemodulator);
 
-		mLSMDemodulator.setSymbolListener( mQPSKSlicer );
+        mLSMDemodulator.setSymbolListener(mQPSKSlicer);
 
-		mMessageFramer = new P25MessageFramer( aliasList, mLSMDemodulator );
+        mMessageFramer = new P25MessageFramer(aliasList, mLSMDemodulator.getCostasLoop());
-		mQPSKSlicer.addListener( mMessageFramer );
+        mQPSKSlicer.addListener(mMessageFramer);
 
-        mMessageFramer.setListener( getMessageProcessor() );
+        mMessageFramer.setListener(getMessageProcessor());
-	}
+    }
 
-	public void dispose()
+    public void dispose()
-	{
+    {
-		super.dispose();
+        super.dispose();
 
-		mBasebandFilter.dispose();
+        mBasebandFilter.dispose();
-		mBasebandFilter = null;
+        mBasebandFilter = null;
 
-		mStreamConverter.dispose();
+        mStreamConverter.dispose();
-		mStreamConverter = null;
+        mStreamConverter = null;
 
-		mAGC.dispose();
+        mAGC.dispose();
-		mAGC = null;
+        mAGC = null;
 
-		mLSMDemodulator.dispose();
+        mLSMDemodulator.dispose();
-		mLSMDemodulator = null;
+        mLSMDemodulator = null;
 
-		mQPSKSlicer.dispose();
+        mQPSKSlicer.dispose();
-		mQPSKSlicer = null;
+        mQPSKSlicer = null;
 
-		mMessageFramer.dispose();
+        mMessageFramer.dispose();
-		mMessageFramer = null;
+        mMessageFramer = null;
-	}
+    }
 
     @Override
     public void setFrequencyChangeListener(Listener<FrequencyChangeEvent> listener)
@@ -130,130 +124,34 @@ public class P25_LSMDecoder extends P25Decoder implements IComplexBufferListener
     }
 
     @Override
-	public Listener<ComplexBuffer> getComplexBufferListener()
+    public Listener<ComplexBuffer> getComplexBufferListener()
-	{
-		return mBasebandFilter;
-	}
-
-	public Modulation getModulation()
-	{
-		return Modulation.CQPSK;
-	}
-	
-	/**
-	 * Provides a list of instrumentation taps for monitoring internal processing
-	 */
-	@Override
-    public List<TapGroup> getTapGroups()
     {
-		if( mAvailableTaps == null )
+        return mBasebandFilter;
-		{
-			mAvailableTaps = new ArrayList<>();
-
-			TapGroup group = new TapGroup( "P25 LSM Decoder" );
-			
-			group.add( new ComplexTap( INSTRUMENT_BASEBAND_FILTER_OUTPUT, 0, 1.0f ) );
-			group.add( new ComplexTap( INSTRUMENT_AGC_OUTPUT, 0, 1.0f ) );
-			group.add( new QPSKTap( INSTRUMENT_LSM_DEMODULATOR_OUTPUT, 0, 1.0f ) );
-			group.add( new DibitTap( INSTRUMENT_QPSK_SLICER_OUTPUT, 0, 0.1f ) );
-
-			mAvailableTaps.add( group );
-			
-			if( mLSMDemodulator != null )
-			{
-				mAvailableTaps.addAll( mLSMDemodulator.getTapGroups() );
-			}
-		}
-		
-		return mAvailableTaps;
     }
 
-	/**
+    public Modulation getModulation()
-	 * Adds the instrumentation tap
-	 */
-	@Override
-    public void registerTap( Tap tap )
     {
-		if( mLSMDemodulator != null )
+        return Modulation.CQPSK;
-		{
-			mLSMDemodulator.registerTap( tap );
-		}
-		
-		switch( tap.getName() )
-		{
-			case INSTRUMENT_BASEBAND_FILTER_OUTPUT:
-				ComplexSampleTap baseband = (ComplexSampleTap)tap;
-				mStreamConverter.setListener( baseband );
-				baseband.setListener( mAGC );
-				break;
-			case INSTRUMENT_AGC_OUTPUT:
-				ComplexSampleTap agcSymbol = (ComplexSampleTap)tap;
-				mAGC.setListener( agcSymbol );
-				agcSymbol.setListener( mLSMDemodulator );
-				break;
-			case INSTRUMENT_LSM_DEMODULATOR_OUTPUT:
-				QPSKTap qpsk = (QPSKTap)tap;
-				mLSMDemodulator.setSymbolListener( qpsk );
-				qpsk.setListener( mQPSKSlicer );
-				break;
-			case INSTRUMENT_QPSK_SLICER_OUTPUT:
-				mQPSKSlicer.addListener( (DibitTap)tap );
-				break;
-			default:
-				throw new IllegalArgumentException( "Unrecognized tap: " + 
-							tap.getName() );
-		}
     }
 
-	/**
+    @Override
-	 * Removes the instrumentation tap
+    public void reset()
-	 */
-	@Override
-    public void unregisterTap( Tap tap )
     {
-		if( mLSMDemodulator != null )
+        // TODO Auto-generated method stub
-		{
-			mLSMDemodulator.unregisterTap( tap );
-		}
 
-		switch( tap.getName() )
-		{
-			case INSTRUMENT_BASEBAND_FILTER_OUTPUT:
-				mStreamConverter.setListener( mAGC );
-				break;
-			case INSTRUMENT_AGC_OUTPUT:
-				mAGC.setListener( mLSMDemodulator );
-				break;
-			case INSTRUMENT_LSM_DEMODULATOR_OUTPUT:
-				mLSMDemodulator.setSymbolListener( mQPSKSlicer );
-				break;
-			case INSTRUMENT_QPSK_SLICER_OUTPUT:
-				mQPSKSlicer.removeListener( (DibitTap)tap );
-				break;
-			default:
-				throw new IllegalArgumentException( "Unrecognized tap: " + 
-							tap.getName() );
-		}
     }
 
-	@Override
+    @Override
-	public void reset()
+    public void start(ScheduledExecutorService executor)
-	{
+    {
-		// TODO Auto-generated method stub
+        // TODO Auto-generated method stub
 
-	}
+    }
 
-	@Override
+    @Override
-	public void start( ScheduledExecutorService executor )
+    public void stop()
-	{
+    {
-		// TODO Auto-generated method stub
+        // TODO Auto-generated method stub
 
-	}
+    }
-
-	@Override
-	public void stop()
-	{
-		// TODO Auto-generated method stub
-		
-	}
 }

src/main/java/io/github/dsheirer/module/decode/p25/message/tsbk/osp/control/SyncBroadcast.java

@@ -78,7 +78,7 @@ public class SyncBroadcast extends TSBKMessage
         
         if( isMicroslotsLockedToMinuteRollover() )
         {
-            sb.append( " MICROSLOT-MINUTE ROLLOVER:LOCKED" );
+            sb.append( " MICROSLOT-MINUTE ROLLOVER:SLOW" );
         }
         else
         {

src/main/java/io/github/dsheirer/module/decode/passport/PassportDecoder.java

@@ -63,7 +63,7 @@ public class PassportDecoder extends Decoder
 
 		mPassportMessageProcessor = new PassportMessageProcessor( aliasList );
 		mPassportMessageFramer.addMessageListener( mPassportMessageProcessor );
-		mPassportMessageProcessor.setMessageListener( this );
+		mPassportMessageProcessor.setMessageListener( getMessageListener() );
 	}
 
 	@Override

src/main/java/io/github/dsheirer/module/decode/tait/Tait1200Decoder.java

@@ -104,8 +104,8 @@ public class Tait1200Decoder extends Decoder implements IFilteredRealBufferListe
         mMessageFramerGPS.addMessageListener( mMessageAProcessor );
         mMessageFramerANI.addMessageListener( mMessageBProcessor );
         
-        mMessageAProcessor.setMessageListener( this );
+        mMessageAProcessor.setMessageListener(getMessageListener());
-        mMessageBProcessor.setMessageListener( this );
+        mMessageBProcessor.setMessageListener(getMessageListener());
 	}
     
     public void dispose()

src/main/java/io/github/dsheirer/record/RecorderManager.java

@@ -42,6 +42,7 @@ public class RecorderManager implements Listener<AudioPacket>
     private static final Logger mLog = LoggerFactory.getLogger(RecorderManager.class);
 
     public static final int AUDIO_SAMPLE_RATE = 8000;
+    public static final int BASEBAND_SAMPLE_RATE = 48000;
     public static final long IDLE_RECORDER_REMOVAL_THRESHOLD = 6000; //6 seconds
 
     private Map<String,AudioPacketWaveRecorder> mRecorders = new HashMap<>();
@@ -229,7 +230,7 @@ public class RecorderManager implements Listener<AudioPacket>
         sb.append(SystemProperties.getInstance().getApplicationFolder("recordings"));
         sb.append(File.separator).append(channelName).append("_baseband");
 
-        return new ComplexBufferWaveRecorder(AUDIO_SAMPLE_RATE, sb.toString());
+        return new ComplexBufferWaveRecorder(BASEBAND_SAMPLE_RATE, sb.toString());
     }
 
     /**

src/main/java/io/github/dsheirer/sample/ConversionUtils.java

@@ -21,14 +21,13 @@ public class ConversionUtils
      */
     public static float[] convertFromSigned16BitSamples( ByteBuffer buffer )
     {
-    	ShortBuffer byteBuffer = 
+    	ShortBuffer byteBuffer = buffer.order( ByteOrder.LITTLE_ENDIAN ).asShortBuffer();
-    			buffer.order( ByteOrder.LITTLE_ENDIAN ).asShortBuffer();
     	
     	float[] samples = new float[ buffer.limit() / 2 ];
     	
     	for( int x = 0; x < samples.length; x++ )
     	{
-    		samples[ x ] = (float)byteBuffer.get() / 32767.0f;
+    		samples[ x ] = (float)byteBuffer.get() / (float)Short.MAX_VALUE;
     	}
 
     	return samples;

src/main/java/io/github/dsheirer/sample/complex/Complex.java

@@ -27,407 +27,424 @@ import java.io.Serializable;
  */
 public class Complex implements Serializable
 {
-	private final static Logger mLog = 
+    private final static Logger mLog = LoggerFactory.getLogger(Complex.class);
-			LoggerFactory.getLogger( Complex.class );
 
-	private static final long serialVersionUID = 1L;
+    private static final long serialVersionUID = 1L;
 
     private float mLeft;
-	private float mRight;
+    private float mRight;
 
-	public Complex( float left, float right )
+    public Complex(float left, float right)
-	{
+    {
-		mLeft = left;
+        mLeft = left;
-		mRight = right;
+        mRight = right;
-	}
+    }
 
-	public Complex()
+    public Complex()
-	{
+    {
-		this( 0.0f, 0.0f );
+        this(0.0f, 0.0f);
-	}
+    }
 
-	public void setInphase( float inphase )
+    public void setInphase(float inphase)
-	{
+    {
-		mLeft = inphase;
+        mLeft = inphase;
-	}
+    }
 
-	public void setQuadrature( float quadrature )
+    public void setQuadrature(float quadrature)
-	{
+    {
-		mRight = quadrature;
+        mRight = quadrature;
-	}
+    }
 
-	public void setValues( float inphase, float quadrature )
+    public void setValues(float inphase, float quadrature)
-	{
+    {
-		mLeft = inphase;
+        mLeft = inphase;
-		mRight = quadrature;
+        mRight = quadrature;
-	}
+    }
 
-	public Complex copy()
+    public void setValues(Complex sampleToCopy)
-	{
+    {
-		return new Complex( mLeft, mRight );
+        mLeft = sampleToCopy.left();
-	}
+        mRight = sampleToCopy.right();
+    }
 
-	public String toString()
+    public Complex copy()
-	{
+    {
-		StringBuilder sb = new StringBuilder();
+        return new Complex(mLeft, mRight);
+    }
 
-		sb.append( "I:" );
+    public String toString()
-		sb.append( mLeft );
+    {
-		sb.append( " Q:" );
+        StringBuilder sb = new StringBuilder();
-		sb.append( mRight );
 
-		return sb.toString();
+        sb.append("I:");
-	}
+        sb.append(mLeft);
+        sb.append(" Q:");
+        sb.append(mRight);
 
-	/**
+        return sb.toString();
-	 * Returns a new sample representing the conjugate of this one
+    }
-	 */
-	public Complex conjugate()
-	{
-		return new Complex( mLeft, -mRight );
-	}
 
-	/**
+    /**
-	 * Multiplies this sample by the scalor value
+     * Returns a new sample representing the conjugate of this one
-	 */
+     */
-	public void multiply( float scalor )
+    public Complex conjugate()
-	{
+    {
-		mLeft *= scalor;
+        return new Complex(mLeft, -mRight);
-		mRight *= scalor;
+    }
-	}
 
-	public static Complex multiply( Complex sample, float scalor )
+    /**
-	{
+     * Multiplies this sample by the scalor value
-		return new Complex( sample.left() * scalor, 
+     */
-								  sample.right() * scalor );
+    public void multiply(float scalor)
-	}
+    {
+        mLeft *= scalor;
+        mRight *= scalor;
+    }
 
-	/**
+    public static Complex multiply(Complex sample, float scalor)
-	 * Calculates the inphase component of multiplying two complex numbers, A and B.
+    {
-	 */
+        return new Complex(sample.left() * scalor,
-	public static float multiplyInphase( float inphaseA, float quadratureA, float inphaseB, float quadratureB )
+            sample.right() * scalor);
-	{
+    }
-		return ( inphaseA * inphaseB ) - ( quadratureA * quadratureB );
-	}
 
-	/**
+    /**
-	 * Calculates the quadrature component of multiplying two complex numbers, A and B.
+     * Calculates the inphase component of multiplying two complex numbers, A and B.
-	 */
+     */
-	public static float multiplyQuadrature( float inphaseA, float quadratureA, float inphaseB, float quadratureB )
+    public static float multiplyInphase(float inphaseA, float quadratureA, float inphaseB, float quadratureB)
-	{
+    {
-		return ( quadratureA * inphaseB ) + ( inphaseA * quadratureB );
+        return (inphaseA * inphaseB) - (quadratureA * quadratureB);
-	}
+    }
 
-	/**
+    /**
-	 * Multiplies this sample by the multiplier sample
+     * Calculates the quadrature component of multiplying two complex numbers, A and B.
-	 */
+     */
-	public void multiply( Complex multiplier )
+    public static float multiplyQuadrature(float inphaseA, float quadratureA, float inphaseB, float quadratureB)
-	{
+    {
-		float inphase = multiplyInphase( inphase(), quadrature(), 
+        return (quadratureA * inphaseB) + (inphaseA * quadratureB);
-				multiplier.inphase(), multiplier.quadrature() );
+    }
-		float quadrature = multiplyQuadrature( inphase(), quadrature(), 
-				multiplier.inphase(), multiplier.quadrature() );
 
-		mLeft = inphase;
+    /**
-		mRight = quadrature;
+     * Multiplies this sample by the multiplier sample
-	}
+     */
+    public void multiply(Complex multiplier)
+    {
+        float inphase = multiplyInphase(inphase(), quadrature(),
+            multiplier.inphase(), multiplier.quadrature());
+        float quadrature = multiplyQuadrature(inphase(), quadrature(),
+            multiplier.inphase(), multiplier.quadrature());
 
-	/**
+        mLeft = inphase;
-	 * Multiplies both samples returning a new sample with the results
+        mRight = quadrature;
-	 */
+    }
-	public static Complex multiply( Complex sample1, Complex sample2 )
-	{
-		float inphase = multiplyInphase( sample1.inphase(), sample1.quadrature(), 
-				sample2.inphase(), sample2.quadrature() );
-		float quadrature = multiplyQuadrature( sample1.inphase(), sample1.quadrature(), 
-				sample2.inphase(), sample2.quadrature() );
 
-		return new Complex( inphase, quadrature );
+    /**
-	}
+     * Multiplies both samples returning a new sample with the results
+     */
+    public static Complex multiply(Complex sample1, Complex sample2)
+    {
+        float inphase = multiplyInphase(sample1.inphase(), sample1.quadrature(),
+            sample2.inphase(), sample2.quadrature());
+        float quadrature = multiplyQuadrature(sample1.inphase(), sample1.quadrature(),
+            sample2.inphase(), sample2.quadrature());
 
-	public static Complex multiply( Complex sample, 
+        return new Complex(inphase, quadrature);
-										  Float inphase, Float quadrature )
+    }
-	{
-		float i = multiplyInphase( sample.inphase(), sample.quadrature(), 
-				inphase, quadrature );
-		float q = multiplyQuadrature( sample.inphase(), sample.quadrature(), 
-				inphase, quadrature );
 
-		return new Complex( i, q );
+    public static Complex multiply(Complex sample,
-	}
+                                   Float inphase, Float quadrature)
+    {
+        float i = multiplyInphase(sample.inphase(), sample.quadrature(),
+            inphase, quadrature);
+        float q = multiplyQuadrature(sample.inphase(), sample.quadrature(),
+            inphase, quadrature);
 
-	public static Complex multiply( Float inphase, Float quadrature, Complex sample )
+        return new Complex(i, q);
-	{
+    }
-		float i = multiplyInphase( inphase, quadrature, sample.inphase(), sample.quadrature() );
-		float q = multiplyQuadrature( inphase, quadrature, sample.inphase(), sample.quadrature() );
 
-		return new Complex( i, q );
+    public static Complex multiply(Float inphase, Float quadrature, Complex sample)
-	}
+    {
+        float i = multiplyInphase(inphase, quadrature, sample.inphase(), sample.quadrature());
+        float q = multiplyQuadrature(inphase, quadrature, sample.inphase(), sample.quadrature());
 
-	public static Complex multiply( float inphaseA, float quadratureA, float inphaseB, float quadratureB )
+        return new Complex(i, q);
-	{
+    }
-		float i = multiplyInphase( inphaseA, quadratureA, inphaseB, quadratureB );
-		float q = multiplyQuadrature( inphaseA, quadratureA, inphaseB, quadratureB );
 
-		return new Complex( i, q );
+    public static Complex multiply(float inphaseA, float quadratureA, float inphaseB, float quadratureB)
-	}
+    {
+        float i = multiplyInphase(inphaseA, quadratureA, inphaseB, quadratureB);
+        float q = multiplyQuadrature(inphaseA, quadratureA, inphaseB, quadratureB);
 
-	/**
+        return new Complex(i, q);
-	 * Adds the adder sample value to this sample
+    }
-	 */
-	public void add( Complex adder )
-	{
-		mLeft += adder.left();
-		mRight += adder.right();
-	}
 
-	/**
+    /**
-	 * Adds the two complex samples returning a new complex sample with the result
+     * Adds the adder sample value to this sample
-	 */
+     */
-	public static Complex add( Complex first, Complex second )
+    public void add(Complex adder)
-	{
+    {
-		return new Complex( first.left() + second.left(), 
+        mLeft += adder.left();
-								  first.right() + second.right() );
+        mRight += adder.right();
-	}
+    }
 
-	/**
+    /**
-	 * Adds the two complex samples returning a new complex sample with the result
+     * Adds the two complex samples returning a new complex sample with the result
-	 */
+     */
-	public static Complex subtract( Complex first, Complex second )
+    public static Complex add(Complex first, Complex second)
-	{
+    {
-		return new Complex( first.left() - second.left(), 
+        return new Complex(first.left() + second.left(),
-								  first.right() - second.right() );
+            first.right() + second.right());
-	}
+    }
 
-	/**
+    /**
-	 * Magnitude of this sample
+     * Adds the two complex samples returning a new complex sample with the result
-	 */
+     */
-	public float magnitude()
+    public static Complex subtract(Complex first, Complex second)
-	{
+    {
-		return (float)Math.sqrt( magnitudeSquared() );
+        return new Complex(first.left() - second.left(),
-	}
+            first.right() - second.right());
+    }
 
-	public static float magnitude( float inphase, float quadrature )
+    /**
-	{
+     * Magnitude of this sample
-		return (float)Math.sqrt( ( inphase * inphase  ) + ( quadrature * quadrature ) );
+     */
-	}
+    public float magnitude()
+    {
+        return (float)Math.sqrt(magnitudeSquared());
+    }
 
-	/**
+    public static float magnitude(float inphase, float quadrature)
-	 * Magnitude squared of this sample
+    {
-	 */
+        return (float)Math.sqrt((inphase * inphase) + (quadrature * quadrature));
-	public float magnitudeSquared()
+    }
-	{
-		return norm();
-	}
 
-	/**
+    /**
-	 * Norm of this sample = ( i * i ) + ( q * q )
+     * Magnitude squared of this sample
-	 */
+     */
-	public float norm()
+    public float magnitudeSquared()
-	{
+    {
-		return (float)( ( inphase() * inphase() ) + 
+        return norm();
-				  ( quadrature() * quadrature() ) );
+    }
-	}
 
-	/**
+    /**
-	 * Returns the vector length to 1 (unit circle)
+     * Norm of this sample = ( i * i ) + ( q * q )
-	 */
+     */
-	public void normalize()
+    public float norm()
-	{
+    {
-		float magnitude = magnitude();
+        return (float)((inphase() * inphase()) +
+            (quadrature() * quadrature()));
+    }
 
-		if( magnitude != 0 )
+    /**
-		{
+     * Returns the vector length to 1 (unit circle)
-			multiply( (float)( 1.0f / magnitude() ) );
+     */
-		}
+    public void normalize()
-	}
+    {
+        float magnitude = magnitude();
 
-	/**
+        if(magnitude != 0)
-	 * Returns the vector length to 1 (unit circle),
+        {
-	 * avoiding square root multiplication
+            multiply((float)(1.0f / magnitude()));
-	 */
+        }
-	public void fastNormalize()
+    }
-	{
-		multiply( (float)( 1.95f - magnitudeSquared() ) );
-	}
 
-	public float left()
+    /**
-	{
+     * Returns the vector length to 1 (unit circle),
-		return mLeft;
+     * avoiding square root multiplication
-	}
+     */
+    public void fastNormalize()
+    {
+        multiply((float)(1.95f - magnitudeSquared()));
+    }
 
-	public float right()
+    public float left()
-	{
+    {
-		return mRight;
+        return mLeft;
-	}
+    }
 
-	public float inphase()
+    public float right()
-	{
+    {
-		return mLeft;
+        return mRight;
-	}
+    }
 
-	/**
+    public float inphase()
-	 * Absolute value of in-phase component
+    {
-	 */
+        return mLeft;
-	public float inPhaseAbsolute()
+    }
-	{
-		return Math.abs( mLeft );
-	}
 
-	public float quadrature()
+    /**
-	{
+     * Absolute value of in-phase component
-		return mRight;
+     */
-	}
+    public float inPhaseAbsolute()
+    {
+        return Math.abs(mLeft);
+    }
 
-	/**
+    public float quadrature()
-	 * Absolute value of quadrature component
+    {
-	 */
+        return mRight;
-	public float quadratureAbsolute()
+    }
-	{
-		return Math.abs( mRight );
-	}
 
-	public float x()
+    /**
-	{
+     * Absolute value of quadrature component
-		return mLeft;
+     */
-	}
+    public float quadratureAbsolute()
+    {
+        return Math.abs(mRight);
+    }
 
-	public float y()
+    public float x()
-	{
+    {
-		return mRight;
+        return mLeft;
-	}
+    }
 
-	public float real()
+    public float y()
-	{
+    {
-		return mLeft;
+        return mRight;
-	}
+    }
 
-	/**
+    public float real()
-	 * Absolute value of real component
+    {
-	 */
+        return mLeft;
-	public float realAbsolute()
+    }
-	{
-		return Math.abs( mLeft );
-	}
 
-	public float imaginary()
+    /**
-	{
+     * Absolute value of real component
-		return mRight;
+     */
-	}
+    public float realAbsolute()
+    {
+        return Math.abs(mLeft);
+    }
 
-	/**
+    public float imaginary()
-	 * Absolute value of imaginary component
+    {
-	 */
+        return mRight;
-	public float imaginaryAbsolute()
+    }
-	{
-		return Math.abs( mRight );
-	}
 
-	/**
+    /**
-	 * Returns the greater absolute value between left and right values 
+     * Absolute value of imaginary component
-	 */
+     */
-	public float maximumAbsolute()
+    public float imaginaryAbsolute()
-	{
+    {
-		if( Math.abs( mLeft ) > Math.abs( mRight ) )
+        return Math.abs(mRight);
-		{
+    }
-			return Math.abs( mLeft );
-		}
-		else
-		{
-			return Math.abs(  mRight );
-		}
-	}
 
-	/**
+    /**
-	 * Creates a new complex sample representing the angle with unit circle
+     * Returns the greater absolute value between left and right values
-	 * magnitude
+     */
-	 * @param angle in radians
+    public float maximumAbsolute()
-	 * @return
+    {
-	 */
+        if(Math.abs(mLeft) > Math.abs(mRight))
-	public static Complex fromAngle( float angle )
+        {
-	{
+            return Math.abs(mLeft);
-		return new Complex( (float)Math.cos( angle ), 
+        }
-								  (float)Math.sin( angle ) );
+        else
-	}
+        {
+            return Math.abs(mRight);
+        }
+    }
 
-	/**
+    /**
-	 * Angle of this sample in radians
+     * Creates a new complex sample representing the angle with unit circle
-	 */
+     * magnitude
-	public float angle()
+     *
-	{
+     * @param angle in radians
-		return (float)Math.atan2( y(), x() );
+     * @return
-	}
+     */
+    public static Complex fromAngle(double angle)
+    {
+        return new Complex((float)Math.cos(angle), (float)Math.sin(angle));
+    }
 
-	/**
+    /**
-	 * Constrains the i and q quantities to +/- value. 
+     * Sets this complex instance with the specified angle in radians.
-	 * 
+     * @param angle in radians
-	 * @param value - maximum absolute value
+     */
-	 */
+    public void setAngle(double angle)
-	public void clip( float value )
+    {
-	{
+        setInphase((float)Math.cos(angle));
-		if( mLeft > value )
+        setQuadrature((float)Math.sin(angle));
-		{
+    }
-			mLeft = value;
-		}
-		else if( mLeft < -value )
-		{
-			mLeft = -value;
-		}
 
-		if( mRight > value )
+    /**
-		{
+     * Angle of this sample in radians
-			mRight = value;
+     */
-		}
+    public float angle()
-		else if( mRight < -value )
+    {
-		{
+        return (float)Math.atan2(y(), x());
-			mRight = -value;
+    }
-		}
-	}
 
-	/**
+    public float angleDegrees()
-	 * Angle of this sample in degrees
+    {
-	 */
+        return (float)Math.toDegrees(angle());
-	public float polarAngle()
+    }
-	{
-		return (float)Math.toDegrees( angle() );
-	}
 
-	/**
+    /**
-	 * Provides an approximate magnitude value for this sample.
+     * Constrains the i and q quantities to +/- value.
-	 */
+     *
-	public float envelope()
+     * @param value - maximum absolute value
-	{
+     */
-		return envelope( mLeft, mRight );
+    public void clip(float value)
-	}
+    {
+        if(mLeft > value)
+        {
+            mLeft = value;
+        }
+        else if(mLeft < -value)
+        {
+            mLeft = -value;
+        }
 
-	public static float envelope( float inphase, float quadrature )
+        if(mRight > value)
-	{
+        {
-		float inphaseAbsolute = Math.abs( inphase );
+            mRight = value;
-		float quadratureAbsolute = Math.abs( quadrature );
+        }
+        else if(mRight < -value)
+        {
+            mRight = -value;
+        }
+    }
 
-		if( inphaseAbsolute > quadratureAbsolute )
+    /**
-		{
+     * Angle of this sample in degrees
-			return inphaseAbsolute + ( 0.4f * quadratureAbsolute );
+     */
-		}
+    public float polarAngle()
-		else
+    {
-		{
+        return (float)Math.toDegrees(angle());
-			return quadratureAbsolute + ( 0.4f * inphaseAbsolute );
+    }
-		}
-	}
 
-	public static void main( String[] args )
+    /**
-	{
+     * Provides an approximate magnitude value for this sample.
-		double angle = Math.PI;  //180 degrees
+     */
+    public float envelope()
+    {
+        return envelope(mLeft, mRight);
+    }
 
-		Complex s1 = new Complex( (float)Math.sin( angle ), (float)Math.cos( angle ) );
+    public static float envelope(float inphase, float quadrature)
+    {
+        float inphaseAbsolute = Math.abs(inphase);
+        float quadratureAbsolute = Math.abs(quadrature);
 
-		Complex tap = new Complex( 1.0f, -0.1f );
+        if(inphaseAbsolute > quadratureAbsolute)
+        {
+            return inphaseAbsolute + (0.4f * quadratureAbsolute);
+        }
+        else
+        {
+            return quadratureAbsolute + (0.4f * inphaseAbsolute);
+        }
+    }
 
-		Complex convolved = Complex.multiply( s1, tap );
+    public static void main(String[] args)
+    {
+        Complex ROTATE_FROM_MINUS_45 = Complex.fromAngle(1.0 * Math.PI / 4.0);
+        Complex ROTATE_FROM_PLUS_135 = Complex.fromAngle(-3.0 * Math.PI / 4.0);
+        mLog.debug("REF: " + ROTATE_FROM_MINUS_45.toString());
 
-		mLog.debug( "s: " + s1.toString() +
+        Complex symbol = new Complex(0.7665009f, -0.6422432f);
-					" t: " + tap.toString() +
+        mLog.debug("SYM: " + symbol.toString());
-					" convolved: " + convolved.toString() );
 
-	}
+        symbol.multiply(ROTATE_FROM_MINUS_45);
+        mLog.debug("DER: " + symbol.toString());
+    }
 }

src/main/java/io/github/dsheirer/source/IControllableFileSource.java

@@ -1,3 +1,18 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 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 io.github.dsheirer.source;
 
 import javax.sound.sampled.UnsupportedAudioFileException;
@@ -10,22 +25,24 @@ import java.io.IOException;
  */
 public interface IControllableFileSource
 {
-	/**
+    /**
-	 * Opens the file source
+     * Opens the file source
-	 */
+     */
-	public void open() throws IOException, UnsupportedAudioFileException;
+    public void open() throws IOException, UnsupportedAudioFileException;
 
-	public void close() throws IOException;
+    public void close() throws IOException;
 
-	public File getFile();
+    public File getFile();
 
-	public void next( int frames ) throws IOException;
+    public void next(int frames) throws IOException;
 
-	public void next( int frames, boolean broadcast ) throws IOException;
+    public void next(int frames, boolean broadcast) throws IOException;
 
-	public long getFrameCount() throws IOException;
+    public long getFrameCount() throws IOException;
 
-	public void setListener( IFrameLocationListener listener );
+    public int getSampleRate();
 
-	public void removeListener( IFrameLocationListener listener );
+    public void setListener(IFrameLocationListener listener);
+
+    public void removeListener(IFrameLocationListener listener);
 }

src/main/java/io/github/dsheirer/source/tuner/TunerChannelSource.java

@@ -469,6 +469,7 @@ public class TunerChannelSource extends ComplexSource implements IFrequencyChang
             {
                 //Frequency correction requests are the only change requests supported from downstream components
                 case REQUEST_CHANNEL_FREQUENCY_CORRECTION_CHANGE:
+                    mLog.debug("Got a freq corr change request: " + event.getValue().intValue());
                     setFrequencyCorrection(event.getValue().intValue());
                     break;
             }

src/main/java/io/github/dsheirer/source/wave/ComplexWaveSource.java

@@ -167,13 +167,8 @@ public class ComplexWaveSource extends ComplexSource implements IControllableFil
         if(mInputStream != null)
         {
             mInputStream.close();
+            mInputStream = null;
         }
-        else
-        {
-            throw new IOException("Can't close wave source - was not opened");
-        }
-
-        mInputStream = null;
     }
 
     /**
@@ -239,8 +234,7 @@ public class ComplexWaveSource extends ComplexSource implements IControllableFil
                     buffer = Arrays.copyOf(buffer, samplesRead);
                 }
 
-                float[] samples = ConversionUtils
+                float[] samples = ConversionUtils.convertFromSigned16BitSamples(buffer);
-                    .convertFromSigned16BitSamples(buffer);
 
                 mListener.receive(new ComplexBuffer(samples));
             }