Updates build to Version 0.4.0 Alpha 2

372 Icecast Streaming Reconnect and Metadata Updates

.idea/dictionaries/denny.xml

@@ -14,6 +14,7 @@
       <w>nutall</w>
       <w>overflowable</w>
       <w>polyphase</w>
+      <w>qpsk</w>
       <w>remez</w>
       <w>resampler</w>
       <w>samplerate</w>

build.gradle

@@ -15,7 +15,7 @@ repositories {
     mavenCentral()
 }
 
-version = '0.4.0-alpha.1'
+version = '0.4.0-alpha.2'
 sourceCompatibility = 1.8
 
 sourceSets {

src/main/java/io/github/dsheirer/audio/broadcast/AudioBroadcaster.java

@@ -245,7 +245,11 @@ public abstract class AudioBroadcaster implements Listener<AudioRecording>
     {
         if(mBroadcastState != state)
         {
-            mLog.info("[" + getStreamName() + "] status: " + state);
+            if(state == BroadcastState.CONNECTED || state == BroadcastState.DISCONNECTED)
+            {
+                mLog.info("[" + getStreamName() + "] status: " + state);
+            }
+
             mBroadcastState = state;
 
             broadcast(new BroadcastEvent(this, BroadcastEvent.Event.BROADCASTER_STATE_CHANGE));

src/main/java/io/github/dsheirer/audio/broadcast/BroadcastState.java

@@ -70,6 +70,11 @@ public enum BroadcastState
      */
     MOUNT_POINT_IN_USE("Mount Point In Use", false),
 
+    /**
+     * Network is unavailable or the server address cannot be resolved
+     */
+    NETWORK_UNAVAILABLE("Network Unavailable", false),
+
     /**
      * Server is not known or reachable
      */

src/main/java/io/github/dsheirer/audio/broadcast/BroadcastStatusPanel.java

@@ -20,9 +20,14 @@ package io.github.dsheirer.audio.broadcast;
 
 import net.miginfocom.swing.MigLayout;
 
-import javax.swing.*;
+import javax.swing.JLabel;
+import javax.swing.JPanel;
+import javax.swing.JScrollPane;
+import javax.swing.JTable;
+import javax.swing.SwingConstants;
 import javax.swing.table.DefaultTableCellRenderer;
-import java.awt.*;
+import java.awt.Color;
+import java.awt.Component;
 
 public class BroadcastStatusPanel extends JPanel
 {
@@ -96,7 +101,8 @@ public class BroadcastStatusPanel extends JPanel
                         setBackground(table.getBackground());
                         setForeground(Color.LIGHT_GRAY);
                     }
-                    else if(state == BroadcastState.INVALID_SETTINGS)
+                    else if(state == BroadcastState.INVALID_SETTINGS ||
+                            state == BroadcastState.NETWORK_UNAVAILABLE)
                     {
                         setBackground(Color.YELLOW);
                         setForeground(table.getForeground());

src/main/java/io/github/dsheirer/audio/broadcast/icecast/IcecastBroadcastMetadataUpdater.java

@@ -22,6 +22,7 @@ import io.github.dsheirer.audio.broadcast.IBroadcastMetadataUpdater;
 import io.github.dsheirer.channel.metadata.Metadata;
 import io.github.dsheirer.properties.SystemProperties;
 import io.github.dsheirer.util.ThreadPool;
+import org.apache.mina.core.RuntimeIoException;
 import org.apache.mina.core.future.ConnectFuture;
 import org.apache.mina.core.service.IoHandlerAdapter;
 import org.apache.mina.core.session.IoSession;
@@ -35,7 +36,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.UnsupportedEncodingException;
-import java.net.ConnectException;
 import java.net.InetSocketAddress;
 import java.net.URLEncoder;
 import java.nio.channels.UnresolvedAddressException;
@@ -117,70 +117,64 @@ public class IcecastBroadcastMetadataUpdater implements IBroadcastMetadataUpdate
     {
         mMetadataQueue.offer(getSong(metadata));
 
-        if(mUpdating.compareAndSet(false, true))
+        if(!mUpdating.get() && !mMetadataQueue.isEmpty())
         {
-            String song = mMetadataQueue.poll();
+            Runnable runnable =  new Runnable()
-
-            while(song != null)
             {
-                HttpRequest updateRequest = createUpdateRequest(song);
+                @Override
-
+                public void run()
-                if(updateRequest != null)
                 {
-                    ThreadPool.SCHEDULED.schedule(new Runnable()
+                    if(!mMetadataQueue.isEmpty() && mUpdating.compareAndSet(false, true))
                     {
-                        @Override
+                        try
-                        public void run()
                         {
-                            try
+                            ConnectFuture connectFuture = getSocketConnector()
-                            {
+                                .connect(new InetSocketAddress(mIcecastConfiguration.getHost(),
-                                ConnectFuture connectFuture = getSocketConnector()
+                                    mIcecastConfiguration.getPort()));
-                                    .connect(new InetSocketAddress(mIcecastConfiguration.getHost(),
+                            connectFuture.awaitUninterruptibly();
-                                        mIcecastConfiguration.getPort()));
+                            IoSession session = connectFuture.getSession();
-                                connectFuture.awaitUninterruptibly();
-                                IoSession session = connectFuture.getSession();
 
-                                if(session != null)
+                            if(session != null)
-                                {
-                                    session.write(updateRequest);
-                                }
-                            }
-                            catch(UnresolvedAddressException uae)
                             {
-                                //Do nothing - the server is temporarily unavailable
+                                String song = mMetadataQueue.poll();
-                            }
-                            catch(Exception e)
-                            {
-                                Throwable throwableCause = e.getCause();
 
-                                if(throwableCause instanceof ConnectException)
+                                while(song != null)
                                 {
-                                    //Do nothing, the server is unavailable
+                                    HttpRequest updateRequest = createUpdateRequest(song);
-                                }
+
-                                else if(throwableCause instanceof UnresolvedAddressException)
+                                    if(updateRequest != null)
-                                {
-                                    //Do nothing - the server is temporarily unavailable
-                                }
-                                else
-                                {
-                                    if(!mStackTraceLoggingSuppressed)
                                     {
-                                        mLog.error("Error sending metadata update.  Future errors will " +
+                                        session.write(updateRequest);
-                                            "be suppressed", e);
-
-                                        mStackTraceLoggingSuppressed = true;
                                     }
+
+                                    //Fetch next metadata update to send
+                                    song = mMetadataQueue.poll();
                                 }
+
+                                session.closeNow();
                             }
                         }
-                    }, 0l, TimeUnit.SECONDS);
+                        catch(UnresolvedAddressException | RuntimeIoException ure)
+                        {
+                            //Do nothing - the server is temporarily unavailable
+                        }
+                        catch(Exception e)
+                        {
+                            Throwable throwableCause = e.getCause();
+
+                            if(!mStackTraceLoggingSuppressed)
+                            {
+                                mLog.error("Error sending metadata update.  Future errors will be suppressed", e);
+                                mStackTraceLoggingSuppressed = true;
+                            }
+                        }
+
+                        mUpdating.set(false);
+                    }
                 }
+            };
 
-                //Fetch next metadata update to send
+            ThreadPool.SCHEDULED.schedule(runnable, 0l, TimeUnit.SECONDS);
-                song = mMetadataQueue.poll();
-            }
-
-            mUpdating.set(false);
         }
     }
 

src/main/java/io/github/dsheirer/audio/broadcast/icecast/IcecastTCPAudioBroadcaster.java

@@ -27,15 +27,14 @@ import org.apache.mina.core.RuntimeIoException;
 import org.apache.mina.core.future.ConnectFuture;
 import org.apache.mina.core.service.IoHandlerAdapter;
 import org.apache.mina.core.session.IoSession;
-import org.apache.mina.core.write.WriteTimeoutException;
 import org.apache.mina.filter.codec.ProtocolCodecFilter;
 import org.apache.mina.transport.socket.nio.NioSocketConnector;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
-import java.net.ConnectException;
 import java.net.InetSocketAddress;
+import java.net.SocketException;
 import java.nio.channels.UnresolvedAddressException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -46,7 +45,8 @@ public class IcecastTCPAudioBroadcaster extends IcecastAudioBroadcaster
     private final static String TERMINATOR = "\r\n";
     private final static String SEPARATOR = ":";
     private static final long RECONNECT_INTERVAL_MILLISECONDS = 3000; //3 seconds
-    private static final long CONNECTION_ATTEMPT_TIMEOUT = 5000; //5 seconds
+    private static final long CONNECTION_ATTEMPT_TIMEOUT_MILLISECONDS = 5000; //5 seconds
+    private static final int WRITE_TIMEOUT_SECONDS = 5;
 
     private NioSocketConnector mSocketConnector;
     private IoSession mStreamingSession = null;
@@ -101,7 +101,7 @@ public class IcecastTCPAudioBroadcaster extends IcecastAudioBroadcaster
             if(mSocketConnector == null)
             {
                 mSocketConnector = new NioSocketConnector();
-                mSocketConnector.setConnectTimeoutCheckInterval(CONNECTION_ATTEMPT_TIMEOUT);
+                mSocketConnector.getSessionConfig().setWriteTimeout(WRITE_TIMEOUT_SECONDS);
 
 //                LoggingFilter loggingFilter = new LoggingFilter(IcecastTCPAudioBroadcaster.class);
 //                loggingFilter.setMessageSentLogLevel(LogLevel.NONE);
@@ -127,45 +127,41 @@ public class IcecastTCPAudioBroadcaster extends IcecastAudioBroadcaster
                             .connect(new InetSocketAddress(getBroadcastConfiguration().getHost(),
                                 getBroadcastConfiguration().getPort()));
 
-                        boolean connected = future.await(CONNECTION_ATTEMPT_TIMEOUT, TimeUnit.MILLISECONDS);
+                        boolean connected = future.await(CONNECTION_ATTEMPT_TIMEOUT_MILLISECONDS, TimeUnit.MILLISECONDS);
 
-                        mStreamingSession = future.getSession();
+                        if(connected)
+                        {
+                            mStreamingSession = future.getSession();
+                            mConnecting.set(false);
+                            return;
+                        }
+                    }
+                    catch(RuntimeIoException rioe)
+                    {
+                        if(rioe.getCause() instanceof SocketException)
+                        {
+                            setBroadcastState(BroadcastState.NETWORK_UNAVAILABLE);
+                            mConnecting.set(false);
+                            return;
+                        }
                     }
                     catch(UnresolvedAddressException uae)
                     {
-                        //What do you do with this?  Nothing.
+                        setBroadcastState(BroadcastState.NETWORK_UNAVAILABLE);
+                        mConnecting.set(false);
+                        return;
                     }
-                    catch(InterruptedException ie)
+                    catch(Exception e)
                     {
-                        //We couldn't connect within the timeout period -- disconnect so that we can try again later
+                        mLog.error("Error", e);
-                        disconnect();
+                        //Disregard ... we'll disconnect and try again
-                    }
-                    catch(RuntimeIoException rie)
-                    {
-                        Throwable throwableCause = rie.getCause();
-
-                        if(throwableCause instanceof ConnectException)
-                        {
-                            setBroadcastState(BroadcastState.NO_SERVER);
-                        }
-                        else if(throwableCause != null)
-                        {
-                            setBroadcastState(BroadcastState.ERROR);
-                            mLog.debug("[" + getStreamName() + "] failed to connect", rie);
-                        }
-                        else
-                        {
-                            setBroadcastState(BroadcastState.ERROR);
-                            mLog.debug("[" + getStreamName() + "] failed to connect - no exception is available");
-                        }
-
-                        disconnect();
                     }
                     catch(Throwable t)
                     {
-                        disconnect();
+                        mLog.error("Throwable error caught", t);
                     }
 
+                    disconnect();
                     mConnecting.set(false);
                 }
             };
@@ -188,6 +184,7 @@ public class IcecastTCPAudioBroadcaster extends IcecastAudioBroadcaster
         }
         else
         {
+            setBroadcastState(BroadcastState.DISCONNECTED);
             mLastConnectionAttempt = System.currentTimeMillis();
         }
     }
@@ -263,49 +260,12 @@ public class IcecastTCPAudioBroadcaster extends IcecastAudioBroadcaster
         @Override
         public void exceptionCaught(IoSession session, Throwable cause) throws Exception
         {
-            if(cause instanceof IOException)
+            if(!(cause instanceof IOException))
-            {
-                IOException ioe = (IOException)cause;
-
-                if(ioe.getMessage() != null)
-                {
-                    String reason = ioe.getMessage();
-
-                    if(connected())
-                    {
-                        disconnect();
-                    }
-                    else if(reason.startsWith("Connection reset"))
-                    {
-                        disconnect();
-                    }
-                    else if(reason.startsWith("Operation timed out"))
-                    {
-                        disconnect();
-                    }
-                    else
-                    {
-                        setBroadcastState(BroadcastState.ERROR);
-                        disconnect();
-                    }
-                }
-                else if(ioe instanceof WriteTimeoutException)
-                {
-                    disconnect();
-                }
-                else
-                {
-                    setBroadcastState(BroadcastState.ERROR);
-                    disconnect();
-                    mLog.error("[" + getStreamName() + "] Unspecified IO error - streaming halted.", cause);
-                }
-            }
-            else
             {
                 mLog.error("[" + getStreamName() + "] Broadcast error", cause);
-                setBroadcastState(BroadcastState.ERROR);
-                disconnect();
             }
+
+            disconnect();
         }
 
         @Override

src/main/java/io/github/dsheirer/bits/ISyncProcessor.java

@@ -1,6 +1,26 @@
+/*******************************************************************************
+ * 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.bits;
 
 public interface ISyncProcessor
 {
-	public void checkSync( long value );
+    /**
+     * Checks if the value matches a known sync pattern
+     * @param value
+     * @return
+     */
+    boolean checkSync(long value);
 }

src/main/java/io/github/dsheirer/bits/MultiSyncPatternMatcher.java

@@ -1,111 +1,130 @@
 /*******************************************************************************
- *     SDR Trunk 
+ * 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
+ * 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,  but WITHOUT ANY WARRANTY; without even the implied
- *     This program is distributed in the hope that it will be useful,
+ * warranty of  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
- *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *
- *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * You should have received a copy of the GNU General Public License  along with this program.
- *     GNU General Public License for more details.
+ * If not, see <http://www.gnu.org/licenses/>
- * 
+ *
- *     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.bits;
 
+import io.github.dsheirer.dsp.symbol.ISyncDetectListener;
 import org.apache.commons.lang3.Validate;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.ArrayList;
 import java.util.List;
 
 /**
- * Multi-Sync pattern matcher.  Accepts multiple sync detector objects for 
+ * Multi-Sync pattern matcher.  Accepts multiple sync detector objects for
  * comparision against the incoming bit stream.
- * 
+ *
  * Note: works for sync patterns up to 63 bits (integer size - 1 ) long.
  * If a 64 bit or larger sync pattern is applied, then the wrapping feature
  * of the Long.rotate methods will wrap the MSB around to the LSB and
  * corrupt the matching value.
- *
  */
 public class MultiSyncPatternMatcher
 {
-	private List<ISyncProcessor> mSyncProcessors = new ArrayList<ISyncProcessor>();
+    private final static Logger mLog = LoggerFactory.getLogger(MultiSyncPatternMatcher.class);
-	
-	private long mBits = 0;
-	private long mMask = 0;
-	
-	public MultiSyncPatternMatcher( int syncSize )
-	{
-		Validate.isTrue(syncSize < 64);
-		
-		//Setup a bit mask of all ones the length of the sync pattern
-		mMask = (long)( ( Math.pow( 2, syncSize ) ) - 1 );
-	}
-	
-	public void dispose()
-	{
-		mSyncProcessors.clear();
-	}
-	
-	/**
-	 * Processes two bits before checking sync processors for a match.
-	 */
-	public void receive( boolean bit1, boolean bit2 )
-	{
-		mBits = Long.rotateLeft( mBits, 1 );
-		
-		mBits &= mMask;
-		
-		if( bit1 )
-		{
-			mBits += 1;
-		}
 
-		mBits = Long.rotateLeft( mBits, 1 );
+    private ISyncDetectListener mSyncDetectListener;
-		
+    private int mSyncLossThreshold;
-		mBits &= mMask;
+    private int mBitCount;
-		
+    private List<ISyncProcessor> mSyncProcessors = new ArrayList<ISyncProcessor>();
-		if( bit2 )
-		{
-			mBits += 1;
-		}
 
-		for( ISyncProcessor processor: mSyncProcessors )
+    private long mBits = 0;
-		{
+    private long mMask = 0;
-			processor.checkSync( mBits );
-		}
-	}
-	
-	/**
-	 * Processes one bit before checking sync processors for a match.
-	 */
-	public void receive( boolean bit )
-	{
-		mBits = Long.rotateLeft( mBits, 1 );
-		
-		mBits &= mMask;
-		
-		if( bit )
-		{
-			mBits += 1;
-		}
 
-		for( ISyncProcessor processor: mSyncProcessors )
+    public MultiSyncPatternMatcher(ISyncDetectListener syncDetectListener, int syncLossThreshold, int syncSize)
-		{
+    {
-			processor.checkSync( mBits );
+        mSyncDetectListener = syncDetectListener;
-		}
+        mSyncLossThreshold = syncLossThreshold;
-	}
+        Validate.isTrue(syncSize < 64);
 
-	/**
+        //Setup a bit mask of all ones the length of the sync pattern
-	 * Adds a sync processor to receive the bit stream.
+        mMask = (long)((Math.pow(2, syncSize)) - 1);
-	 */
+    }
-	public void add( ISyncProcessor processor )
+
-	{
+    public void dispose()
-		mSyncProcessors.add( processor );
+    {
-	}
+        mSyncProcessors.clear();
+    }
+
+    /**
+     * Processes two bits before checking sync processors for a match.
+     */
+    public void receive(boolean bit1, boolean bit2)
+    {
+        mBits = Long.rotateLeft(mBits, 1);
+
+        mBits &= mMask;
+
+        if(bit1)
+        {
+            mBits += 1;
+        }
+
+        mBits = Long.rotateLeft(mBits, 1);
+
+        mBits &= mMask;
+
+        if(bit2)
+        {
+            mBits += 1;
+        }
+
+        mBitCount += 2;
+
+        for(ISyncProcessor processor : mSyncProcessors)
+        {
+            if(processor.checkSync(mBits))
+            {
+                mSyncDetectListener.syncDetected();
+                mBitCount = 0;
+            }
+        }
+
+        if(mBitCount > mSyncLossThreshold)
+        {
+            mBitCount = 0;
+            mSyncDetectListener.syncLost();
+        }
+    }
+
+    /**
+     * Processes one bit before checking sync processors for a match.
+     */
+    public void receive(boolean bit)
+    {
+        mBits = Long.rotateLeft(mBits, 1);
+
+        mBits &= mMask;
+
+        if(bit)
+        {
+            mBits += 1;
+        }
+
+        for(ISyncProcessor processor : mSyncProcessors)
+        {
+            processor.checkSync(mBits);
+        }
+    }
+
+    /**
+     * Adds a sync processor to receive the bit stream.
+     */
+    public void add(ISyncProcessor processor)
+    {
+        mSyncProcessors.add(processor);
+    }
 }

src/main/java/io/github/dsheirer/bits/SoftSyncDetector.java

@@ -1,50 +1,68 @@
+/*******************************************************************************
+ * 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.bits;
 
 import io.github.dsheirer.dsp.symbol.ISyncDetectListener;
 
 public class SoftSyncDetector implements ISyncProcessor
 {
-	private ISyncDetectListener mListener;
+    private ISyncDetectListener mListener;
-	private long mPattern;
+    private long mPattern;
-	private int mThreshold;
+    private int mThreshold;
-	
-	public SoftSyncDetector( ISyncDetectListener listener, long pattern, int threshold )
-	{
-		this( pattern, threshold );
-		
-		mListener = listener;
-	}
-	
-	public SoftSyncDetector( long pattern, int threshold )
-	{
-		mPattern = pattern;
-		mThreshold = threshold;
-	}
-	
-	public void dispose()
-	{
-		mListener = null;
-	}
 
-	@Override
+    public SoftSyncDetector(ISyncDetectListener listener, long pattern, int threshold)
-	public void checkSync( long value )
+    {
-	{
+        this(pattern, threshold);
-		long difference = value ^ mPattern;
+
-		
+        mListener = listener;
-		if( ( difference == 0 || Long.bitCount( difference ) <= mThreshold ) &&
+    }
-			  mListener != null )
+
-		{
+    public SoftSyncDetector(long pattern, int threshold)
-			mListener.syncDetected();
+    {
-		}
+        mPattern = pattern;
-	}
+        mThreshold = threshold;
-	
+    }
-	public void setThreshold( int threshold )
+
-	{
+    public void dispose()
-		mThreshold = threshold;
+    {
-	}
+        mListener = null;
-	
+    }
-	public void setListener( ISyncDetectListener listener )
+
-	{
+    @Override
-		mListener = listener;
+    public boolean checkSync(long value)
-	}
+    {
+        long difference = value ^ mPattern;
+
+        if((difference == 0 || Long.bitCount(difference) <= mThreshold) &&
+            mListener != null)
+        {
+            mListener.syncDetected();
+            return true;
+        }
+
+        return false;
+    }
+
+    public void setThreshold(int threshold)
+    {
+        mThreshold = threshold;
+    }
+
+    public void setListener(ISyncDetectListener listener)
+    {
+        mListener = listener;
+    }
 }

src/main/java/io/github/dsheirer/bits/SyncDetector.java

@@ -1,35 +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.bits;
 
 import io.github.dsheirer.dsp.symbol.ISyncDetectListener;
 
 public class SyncDetector implements ISyncProcessor
 {
-	private long mPattern;
+    private long mPattern;
-	private ISyncDetectListener mListener;
+    private ISyncDetectListener mListener;
 
-	public SyncDetector( long pattern )
+    public SyncDetector(long pattern)
-	{
+    {
-		mPattern = pattern;
+        mPattern = pattern;
-	}
+    }
-	
-	public SyncDetector( long pattern, ISyncDetectListener listener )
-	{
-		this( pattern );
-		
-		mListener = listener;
-	}
-	
-	public void setListener( ISyncDetectListener listener )
-	{
-		mListener = listener;
-	}
 
-	@Override
+    public SyncDetector(long pattern, ISyncDetectListener listener)
-	public void checkSync( long value )
+    {
-	{
+        this(pattern);
-		if( value == mPattern && mListener != null )
+
-		{
+        mListener = listener;
-			mListener.syncDetected();
+    }
-		}
+
-	}
+    public void setListener(ISyncDetectListener listener)
+    {
+        mListener = listener;
+    }
+
+    @Override
+    public boolean checkSync(long value)
+    {
+        if(value == mPattern)
+        {
+            if(mListener != null)
+            {
+                mListener.syncDetected();
+            }
+
+            return true;
+        }
+
+        return false;
+    }
 }

src/main/java/io/github/dsheirer/channel/state/ChannelState.java

@@ -35,17 +35,16 @@ import io.github.dsheirer.module.decode.event.ICallEventProvider;
 import io.github.dsheirer.sample.IOverflowListener;
 import io.github.dsheirer.sample.Listener;
 import io.github.dsheirer.source.ISourceEventListener;
+import io.github.dsheirer.source.ISourceEventProvider;
 import io.github.dsheirer.source.SourceEvent;
 import io.github.dsheirer.source.heartbeat.Heartbeat;
 import io.github.dsheirer.source.heartbeat.IHeartbeatListener;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import static io.github.dsheirer.source.SourceEvent.Event.NOTIFICATION_FREQUENCY_CHANGE;
-
 public class ChannelState extends Module implements ICallEventProvider, IDecoderStateEventListener,
-    IDecoderStateEventProvider, ISourceEventListener, IHeartbeatListener, ISquelchStateProvider,
+    IDecoderStateEventProvider, ISourceEventListener, ISourceEventProvider, IHeartbeatListener,
-    IAttributeChangeRequestListener, IOverflowListener
+    ISquelchStateProvider, IAttributeChangeRequestListener, IOverflowListener
 {
     private final static Logger mLog = LoggerFactory.getLogger(ChannelState.class);
 
@@ -57,12 +56,13 @@ public class ChannelState extends Module implements ICallEventProvider, IDecoder
     private Listener<CallEvent> mCallEventListener;
     private Listener<DecoderStateEvent> mDecoderStateListener;
     private Listener<SquelchState> mSquelchStateListener;
+    private Listener<SourceEvent> mExternalSourceEventListener;
     private DecoderStateEventReceiver mDecoderStateEventReceiver = new DecoderStateEventReceiver();
     private HeartbeatReceiver mHeartbeatReceiver = new HeartbeatReceiver();
     private ChannelType mChannelType;
     private TrafficChannelManager mTrafficChannelEndListener;
     private CallEvent mTrafficChannelCallEvent;
-    private SourceChangeListener mSourceChangeListener;
+    private SourceEventListener mInternalSourceEventListener;
 
     private boolean mSquelchLocked = false;
     private boolean mSelected = false;
@@ -160,12 +160,12 @@ public class ChannelState extends Module implements ICallEventProvider, IDecoder
     @Override
     public Listener<SourceEvent> getSourceEventListener()
     {
-        if(mSourceChangeListener == null)
+        if(mInternalSourceEventListener == null)
         {
-            mSourceChangeListener = new SourceChangeListener();
+            mInternalSourceEventListener = new SourceEventListener();
         }
 
-        return mSourceChangeListener;
+        return mInternalSourceEventListener;
     }
 
     private boolean isStandardChannel()
@@ -255,6 +255,17 @@ public class ChannelState extends Module implements ICallEventProvider, IDecoder
         }
     }
 
+    /**
+     * Broadcasts the source event to a registered external source event listener
+     */
+    protected void broadcast(SourceEvent sourceEvent)
+    {
+        if(mExternalSourceEventListener != null)
+        {
+            mExternalSourceEventListener.receive(sourceEvent);
+        }
+    }
+
     /**
      * Sets the squelch state listener
      */
@@ -516,18 +527,46 @@ public class ChannelState extends Module implements ICallEventProvider, IDecoder
     }
 
     /**
-     * Listener to receive frequency change events and rebroadcast them to the decoder states
+     * Registers the listener to receive source events from the channel state
      */
-    public class SourceChangeListener implements Listener<SourceEvent>
+    @Override
+    public void setSourceEventListener(Listener<SourceEvent> listener)
+    {
+        mExternalSourceEventListener = listener;
+    }
+
+    /**
+     * De-Registers a listener from receiving source events from the channel state
+     */
+    @Override
+    public void removeSourceEventListener()
+    {
+        mExternalSourceEventListener = null;
+    }
+
+    /**
+     * Listener to receive source events.
+     */
+    public class SourceEventListener implements Listener<SourceEvent>
     {
         @Override
         public void receive(SourceEvent sourceEvent)
         {
-            if(sourceEvent.getEvent() == NOTIFICATION_FREQUENCY_CHANGE)
+            switch(sourceEvent.getEvent())
             {
-                long frequency = sourceEvent.getValue().longValue();
+                case NOTIFICATION_FREQUENCY_CHANGE:
-
+                    //Rebroadcast source frequency change events for the decoder(s) to process
-                broadcast(new DecoderStateEvent(this, Event.SOURCE_FREQUENCY, getState(), frequency));
+                    long frequency = sourceEvent.getValue().longValue();
+                    broadcast(new DecoderStateEvent(this, Event.SOURCE_FREQUENCY, getState(), frequency));
+                    break;
+                case NOTIFICATION_MEASURED_FREQUENCY_ERROR:
+                    //Rebroadcast frequency error measurements to external listener if we're currently
+                    //in an active (ie sync locked) state.
+                    if(getState().isActiveState())
+                    {
+                        broadcast(SourceEvent.frequencyErrorMeasurementSyncLocked(sourceEvent.getValue().longValue(), mChannelType.name()));
+                    }
+                    break;
             }
         }
     }

src/main/java/io/github/dsheirer/channel/state/State.java

@@ -109,6 +109,17 @@ public enum State
 
     public abstract boolean canChangeTo(State state);
 
+    /**
+     * Indicates that this state is an active (ie decoding) state and is one of the states
+     * enumerated in the CALL_STATES enumeration set.
+     *
+     * @return true if this state is an active state
+     */
+    public boolean isActiveState()
+    {
+        return CALL_STATES.contains(this);
+    }
+
     public String getDisplayValue()
     {
         return mDisplayValue;

src/main/java/io/github/dsheirer/dsp/filter/channelizer/PolyphaseChannelManager.java

@@ -314,7 +314,7 @@ public class PolyphaseChannelManager implements ISourceEventProcessor
             case NOTIFICATION_SAMPLE_RATE_CHANGE:
                 //Update channel calculator immediately so that channels can be allocated
                 double sampleRate = sourceEvent.getValue().doubleValue();
-                int channelCount = (int)Math.ceil(sampleRate / MINIMUM_CHANNEL_BANDWIDTH);
+                int channelCount = ComplexPolyphaseChannelizerM2.getChannelCount(sampleRate);
                 mChannelCalculator.setRates(sampleRate, channelCount);
                 break;
             case NOTIFICATION_FREQUENCY_AND_SAMPLE_RATE_LOCKED:
@@ -556,6 +556,10 @@ public class PolyphaseChannelManager implements ISourceEventProcessor
                 case NOTIFICATION_FREQUENCY_CORRECTION_CHANGE:
                     //ignore
                     break;
+                case NOTIFICATION_MEASURED_FREQUENCY_ERROR_SYNC_LOCKED:
+                    //Rebroadcast so that the tuner source can process this event
+                    mSourceEventBroadcaster.broadcast(sourceEvent);
+                    break;
                 default:
                     mLog.error("Received unrecognized source event from polyphase channel source [" +
                         sourceEvent.getEvent() + "]");

src/main/java/io/github/dsheirer/dsp/filter/channelizer/PolyphaseChannelResultsBuffer.java

@@ -1,171 +0,0 @@
-/*******************************************************************************
- * 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.channelizer;
-
-import java.util.Arrays;
-
-public class PolyphaseChannelResultsBuffer
-{
-    private long mTimestamp;
-    private int mPointer = 0;
-    private int mMaxSize;
-    private float[][] mChannelResults;
-
-    /**
-     * Buffer containing an array of polyphase channelizer complex channel results.
-     * @param timestamp reference relative to the first channel results.
-     * @param maxSize of channel results to store in this buffer
-     */
-    public PolyphaseChannelResultsBuffer(long timestamp, int maxSize)
-    {
-        mTimestamp = timestamp;
-        mMaxSize = maxSize;
-    }
-
-    /**
-     * Reference timestamp relative to the first channel results contained in this buffer.
-     * @return reference timestamp in milliseconds since epoch
-     */
-    public long getTimestamp()
-    {
-        return mTimestamp;
-    }
-
-    /**
-     * Indicates if this buffer is full
-     */
-    public boolean isFull()
-    {
-        return mPointer >= mMaxSize;
-    }
-
-    /**
-     * Indicates if this buffer is empty
-     */
-    public boolean isEmpty()
-    {
-        return mPointer == 0;
-    }
-
-    /**
-     * Adds the channel results to this buffer
-     * @param channelResults to add
-     * @throws IllegalArgumentException if the buffer is full or if the size of the channel results array is a different
-     * length than any of the preceeding channel results that were added to this buffer
-     */
-    public void add(float[] channelResults) throws IllegalArgumentException
-    {
-        if(mPointer >= mMaxSize)
-        {
-            throw new IllegalArgumentException("Buffer is full - cannot add new channel results");
-        }
-
-        if(mPointer == 0)
-        {
-            mChannelResults = new float[mMaxSize][channelResults.length];
-        }
-        else
-        {
-            int currentLength = mChannelResults[0].length;
-
-            if(channelResults.length != currentLength)
-            {
-                throw new IllegalArgumentException("Channel results length [" + channelResults.length + "] cannot be " +
-                    "a different length than the channel results that are already contained in this buffer [" +
-                    currentLength + "]");
-            }
-        }
-
-        mChannelResults[mPointer++] = channelResults;
-    }
-
-    /**
-     * Channel results array contained in this buffer
-     */
-    public float[][] getChannelResults()
-    {
-        //If this buffer is full, return all of the channel results
-        if(mPointer == mMaxSize)
-        {
-            return mChannelResults;
-        }
-        //Otherwise, truncate the results to return
-        else
-        {
-            return Arrays.copyOf(mChannelResults, mPointer);
-        }
-    }
-
-    /**
-     * Extracts a single I/Q interleaved sample buffer from the channel results
-     * @param iChannelIndex to extract for the inphase sample.  The q index is assumed to be one greater than i.
-     * @return float[] containing interleaved I and Q samples
-     * @throws IllegalArgumentException if this buffer doesn't contain any samples or if the requested channel is
-     * not within the channel range of the contained channel results.
-     */
-    public float[] getChannel(int iChannelIndex)
-    {
-        if(isEmpty())
-        {
-            throw new IllegalArgumentException("Buffer is empty - cannot extract channel [" + iChannelIndex + "]");
-        }
-
-        if(!isValidChannelIndex(iChannelIndex))
-        {
-            throw new IllegalArgumentException("Channel [" + iChannelIndex + "] is not valid for the contained channel " +
-                "results -- max channel is " + getMaxChannelIndex());
-        }
-
-        float[] samples = new float[mChannelResults.length * 2];
-        int pointer = 0;
-
-        int qChannelIndex = iChannelIndex + 1;
-
-        for(int x = 0; x < mPointer; x++)
-        {
-            float[] channelResults = mChannelResults[x];
-
-            samples[pointer++] = channelResults[iChannelIndex];
-            samples[pointer++] = channelResults[qChannelIndex];
-        }
-
-        return samples;
-    }
-
-    /**
-     * Indicates if the channel argument is valid for the contained channel results.
-     * @param channelIndex number (0 to N) to check
-     * @return false if the buffer is empty or if the channel is greater than the contained channel results
-     */
-    private boolean isValidChannelIndex(int channelIndex)
-    {
-        return channelIndex <= getMaxChannelIndex();
-    }
-
-    /**
-     * Maximum channel index represented in the channel results contained in this buffer.
-     * @return max channel number, or 0 if the buffer is empty
-     */
-    private int getMaxChannelIndex()
-    {
-        if(isEmpty())
-        {
-            return 0;
-        }
-
-        return mChannelResults[0].length;
-    }
-}

src/main/java/io/github/dsheirer/dsp/filter/channelizer/PolyphaseChannelSource.java

@@ -237,4 +237,11 @@ public class PolyphaseChannelSource extends TunerChannelSource
             mPolyphaseChannelOutputProcessor.setFrequencyOffset(getFrequencyOffset());
         }
     }
+
+    @Override
+    public String toString()
+    {
+        return "POLYPHASE [" + mPolyphaseChannelOutputProcessor.getInputChannelCount() + "] " +
+            getTunerChannel().getFrequency();
+    }
 }

src/main/java/io/github/dsheirer/dsp/filter/channelizer/output/ChannelOutputProcessor.java

@@ -62,6 +62,12 @@ public abstract class ChannelOutputProcessor implements IPolyphaseChannelOutputP
         mChannelResultsQueue = new OverflowableReusableBufferTransferQueue<>((int)(sampleRate * 3), (int)(sampleRate * 0.5));
     }
 
+    @Override
+    public int getPolyphaseChannelIndexCount()
+    {
+        return mInputChannelCount;
+    }
+
     public void dispose()
     {
         if(mChannelResultsQueue != null)

src/main/java/io/github/dsheirer/dsp/filter/channelizer/output/IPolyphaseChannelOutputProcessor.java

@@ -59,6 +59,11 @@ public interface IPolyphaseChannelOutputProcessor
      */
     void setPolyphaseChannelIndices(List<Integer> indexes);
 
+    /**
+     * List of current polyphase channel indices for the output processor
+     */
+    int getPolyphaseChannelIndexCount();
+
     /**
      * Updates the synthesis filter taps for this output processor
      * @param filter

src/main/java/io/github/dsheirer/dsp/fsk/LTRDecoder.java

@@ -134,6 +134,12 @@ public class LTRDecoder implements Listener<ReusableBuffer>, ISyncDetectListener
         mSynchronizationMonitor.syncDetected();
     }
 
+    @Override
+    public void syncLost()
+    {
+        //no-op
+    }
+
     /**
      * Processes the buffer samples by converting all samples to boolean values reflecting if the sample value is
      * greater than zero (or not).  Average symbol timing offset is calculated for the full buffer and the offset is

src/main/java/io/github/dsheirer/dsp/fsk/SynchronizationMonitor.java

@@ -30,13 +30,13 @@ import org.slf4j.LoggerFactory;
  *
  * Synchronization States:
  *
- *  -COARSE - default state.  demoted from MEDIUM after one message period with no sync detection.
+ * -COARSE - default state.  demoted from MEDIUM after one message period with no sync detection.
  *
- *  -MEDIUM - promoted from COARSE when one sync detection occurs after two message periods, or demoted from FINE
+ * -MEDIUM - promoted from COARSE when one sync detection occurs after two message periods, or demoted from FINE
- *            after two message periods with no sync detections.
+ * after two message periods with no sync detections.
  *
- *  -FINE   - promoted from MEDIUM after two or more consecutive sync detections within the preceding two or more
+ * -FINE   - promoted from MEDIUM after two or more consecutive sync detections within the preceding two or more
- *            message periods.
+ * message periods.
  */
 public class SynchronizationMonitor implements ISyncDetectListener
 {
@@ -50,6 +50,7 @@ public class SynchronizationMonitor implements ISyncDetectListener
 
     /**
      * Constructs the synchronization monitor for the specified message symbol length.
+     *
      * @param messageLength in symbols.
      */
     public SynchronizationMonitor(int messageLength)
@@ -127,6 +128,12 @@ public class SynchronizationMonitor implements ISyncDetectListener
         updateSyncState();
     }
 
+    @Override
+    public void syncLost()
+    {
+        //no-op
+    }
+
     /**
      * Increments the symbol count for each decoded symbol.
      */

src/main/java/io/github/dsheirer/dsp/psk/pll/AdaptivePLLGainMonitor.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.dsp.psk.pll;
+
+import io.github.dsheirer.dsp.symbol.ISyncDetectListener;
+import io.github.dsheirer.module.decode.p25.P25Decoder;
+import io.github.dsheirer.source.SourceEvent;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Monitors decode sync events to adaptively control PLL loop gain.
+ */
+public class AdaptivePLLGainMonitor implements ISyncDetectListener, IFrequencyErrorProcessor
+{
+    private final static Logger mLog = LoggerFactory.getLogger(AdaptivePLLGainMonitor.class);
+
+    private static final int MAX_SYNC_COUNT = 6;
+    private CostasLoop mCostasLoop;
+    private P25Decoder mP25Decoder;
+    private PLLGain mPLLGain = PLLGain.LEVEL_1;
+    private int mSyncCount;
+
+    /**
+     * Constructs an adaptive monitor to monitor the sync state of a decoder and adjust the gain
+     * level of the costas loop accordingly.
+     *
+     * @param costasLoop to receive adaptive gain updates.
+     * @param p25Decoder to receive frequency error source events
+     */
+    public AdaptivePLLGainMonitor(CostasLoop costasLoop, P25Decoder p25Decoder)
+    {
+        mCostasLoop = costasLoop;
+        mCostasLoop.setPLLGain(mPLLGain);
+        mCostasLoop.setFrequencyErrorProcessor(this);
+        mP25Decoder = p25Decoder;
+    }
+
+    /**
+     * Sync detection event.  Updates the running sync count and updates the PLL gain level.
+     */
+    @Override
+    public void syncDetected()
+    {
+        mSyncCount++;
+        update();
+    }
+
+    /**
+     * Sync loss event.  Updates the running sync count and updates the PLL gain level.
+     */
+    @Override
+    public void syncLost()
+    {
+        mSyncCount -= 2;
+        update();
+    }
+
+    /**
+     * Updates the gain state for a sync detect or sync loss
+     */
+    private void update()
+    {
+        if(mSyncCount < 0)
+        {
+            mSyncCount = 0;
+            return;
+        }
+
+        if(mSyncCount > MAX_SYNC_COUNT)
+        {
+            mSyncCount = MAX_SYNC_COUNT;
+            return;
+        }
+
+        PLLGain gain = PLLGain.fromSyncCount(mSyncCount);
+
+        //Only update the costas loop if the gain value changes
+        if(gain != mPLLGain)
+        {
+            mPLLGain = gain;
+            mCostasLoop.setPLLGain(mPLLGain);
+        }
+    }
+
+    /**
+     * Resets the monitor and commands the PLL to use the highest gain level.
+     */
+    public void reset()
+    {
+        mSyncCount = 0;
+        mPLLGain = PLLGain.LEVEL_1;
+        mCostasLoop.setPLLGain(mPLLGain);
+    }
+
+    @Override
+    public void processFrequencyError(long frequencyError)
+    {
+        //Only rebroadcast the costas loop frequency error if the gain level has progressed above the
+        //default gain of 1, meaning that we have received at least 2 sync events
+        if(mPLLGain != PLLGain.LEVEL_1)
+        {
+            mP25Decoder.broadcast(SourceEvent.frequencyErrorMeasurement(frequencyError));
+        }
+    }
+}

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

@@ -41,10 +41,12 @@ public class CostasLoop implements IPhaseLockedLoop
     private double mDamping = Math.sqrt(2.0) / 2.0;
     private double mAlphaGain;
     private double mBetaGain;
-    private Tracking mTracking = Tracking.FASTEST;
+    private PLLGain mPLLGain = PLLGain.LEVEL_1;
     private double mSymbolRate;
     private double mSampleRate;
-    private int mCounter;
+    private IFrequencyErrorProcessor mFrequencyErrorProcessor;
+    private long mFrequencyError;
+    private int mBaudCounter;
 
     /**
      * Costas Loop for tracking and correcting frequency error in a received carrier signal.
@@ -60,6 +62,17 @@ public class CostasLoop implements IPhaseLockedLoop
         updateLoopBandwidth();
     }
 
+    /**
+     * Registers the listener to receive the measured frequency error as tracked by the PLL at one
+     * second intervals.
+     *
+     * @param listener to receive frequency error measurement.
+     */
+    public void setFrequencyErrorProcessor(IFrequencyErrorProcessor listener)
+    {
+        mFrequencyErrorProcessor = listener;
+    }
+
     /**
      * 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.
@@ -89,21 +102,21 @@ public class CostasLoop implements IPhaseLockedLoop
      */
     private void updateLoopBandwidth()
     {
-        double bandwidth = TWO_PI / mTracking.getLoopBandwidth();
+        double bandwidth = TWO_PI / mPLLGain.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
+     * Sets the PLLGain state for this costas loop.  The PLLGain state affects the aggressiveness of the alpha/beta
      * gain values in synchronizing with the signal carrier.
      *
-     * @param tracking
+     * @param PLLGain
      */
-    public void setTracking(Tracking tracking)
+    public void setPLLGain(PLLGain PLLGain)
     {
-        mTracking = tracking;
+        mPLLGain = PLLGain;
         updateLoopBandwidth();
     }
 
@@ -159,7 +172,7 @@ public class CostasLoop implements IPhaseLockedLoop
         mLoopFrequency += (mBetaGain * phaseError);
         mLoopPhase += mLoopFrequency + (mAlphaGain * phaseError);
 
-        /* Normalize phase between +/- 2 * PI */
+        //Normalize phase between +/- 2 * PI
         if(mLoopPhase > TWO_PI)
         {
             mLoopPhase -= TWO_PI;
@@ -170,7 +183,7 @@ public class CostasLoop implements IPhaseLockedLoop
             mLoopPhase += TWO_PI;
         }
 
-        /* Limit frequency to +/- maximum loop frequency */
+        //Limit frequency to +/- maximum loop frequency
         if(mLoopFrequency > mMaximumLoopFrequency)
         {
             mLoopFrequency = mMaximumLoopFrequency;
@@ -181,17 +194,25 @@ public class CostasLoop implements IPhaseLockedLoop
             mLoopFrequency = -mMaximumLoopFrequency;
         }
 
-        //TODO: broadcast channel offset to the tuner to use in auto-adjusting tuner PPM
+        //Broadcast current frequency error measurement once a second to an external listener
-//        mCounter++;
+        mBaudCounter++;
-//
+
-//        if(mCounter > (5 * mSymbolRate))
+        if(mBaudCounter > mSymbolRate)
-//        {
+        {
-//            mCounter = 0;
+            mBaudCounter = 0;
-//            mLog.info("Current Costas Loop Frequency: " + mLoopFrequency + " [" +
+
-//                (int)(mSampleRate / TWO_PI * mLoopFrequency) + " Hz Offset] sample rate [" + mSampleRate + "]");
+            mFrequencyError = (long)(mSampleRate / TWO_PI * mLoopFrequency);
-//        }
+
+            if(mFrequencyErrorProcessor != null)
+            {
+                mFrequencyErrorProcessor.processFrequencyError(mFrequencyError);
+            }
+        }
     }
 
+    /**
+     * Resets the PLL internal tracking values
+     */
     @Override
     public void reset()
     {

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

@@ -16,27 +16,14 @@
 package io.github.dsheirer.dsp.psk.pll;
 
 /**
- * Phase Locked Loop (PLL) tracking bandwidth - controls how fast/slow the PLL tracks the carrier frequency
+ * Interface for passing frequency error measurements.
  */
-public enum Tracking
+public interface IFrequencyErrorProcessor
 {
-    FASTEST(50.0),
-    FAST(100.0),
-    NORMAL(200.0),
-    SLOW(400.0);
-
-    private double mLoopBandwidth;
-
-    Tracking(double loopBandwidth)
-    {
-        mLoopBandwidth = loopBandwidth;
-    }
-
     /**
-     * Loop bandwidth setting
+     * Provides a frequency error measurement to the listener.
+     *
+     * @param error value as measured by the provider
      */
-    public double getLoopBandwidth()
+    void processFrequencyError(long error);
-    {
-        return mLoopBandwidth;
-    }
 }

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

@@ -0,0 +1,87 @@
+/*******************************************************************************
+ * 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 PLLGain
+{
+    LEVEL_1(50.0, 0, 1),
+    LEVEL_2(75.0, 2, 4),
+    LEVEL_3(100.0, 5, 6),
+    LEVEL_4(125.0, 7, 8),
+    LEVEL_5(150.0, 9, 10);
+
+    private double mLoopBandwidth;
+    private int mRangeStart;
+    private int mRangeEnd;
+
+    PLLGain(double loopBandwidth, int start, int end)
+    {
+        mLoopBandwidth = loopBandwidth;
+        mRangeStart = start;
+        mRangeEnd = end;
+    }
+
+    /**
+     * Loop bandwidth setting
+     */
+    public double getLoopBandwidth()
+    {
+        return mLoopBandwidth;
+    }
+
+    public int getRangeStart()
+    {
+        return mRangeStart;
+    }
+
+    public int getRangeEnd()
+    {
+        return mRangeEnd;
+    }
+
+    /**
+     * Look up PLL gain from a running sync detection count.
+     *
+     * @param syncCount 0-10
+     * @return PLL gain appropriate for the sync detection value
+     */
+    public static PLLGain fromSyncCount(int syncCount)
+    {
+        if(syncCount <= LEVEL_1.getRangeEnd())
+        {
+            return LEVEL_1;
+        }
+        else if(syncCount <= LEVEL_2.getRangeEnd())
+        {
+            return LEVEL_2;
+        }
+        else if(syncCount <= LEVEL_3.getRangeEnd())
+        {
+            return LEVEL_3;
+        }
+        else if(syncCount <= LEVEL_4.getRangeEnd())
+        {
+            return LEVEL_4;
+        }
+        else
+        {
+            return LEVEL_5;
+        }
+    }
+}

src/main/java/io/github/dsheirer/dsp/symbol/ISyncDetectListener.java

@@ -15,7 +15,13 @@
  ******************************************************************************/
 package io.github.dsheirer.dsp.symbol;
 
+/**
+ * Listener interface to be notified each time a sync pattern has been detected and/or when the sync
+ * has been lost.
+ */
 public interface ISyncDetectListener
 {
-	void syncDetected();
+    void syncDetected();
+
+    void syncLost();
 }

src/main/java/io/github/dsheirer/gui/instrument/decoder/LJ1200Pane.java

@@ -44,6 +44,12 @@ public class LJ1200Pane extends AbstractAFSK1200Pane
                 {
                     mLog.debug("Tower Sync Detected!");
                 }
+
+                @Override
+                public void syncLost()
+                {
+                    //no-op
+                }
             });
             mDecoder.getTransponderMessageFramer().setSyncDetectListener(new ISyncDetectListener()
             {
@@ -52,6 +58,12 @@ public class LJ1200Pane extends AbstractAFSK1200Pane
                 {
                     mLog.debug("Transponder Sync Detected!");
                 }
+
+                @Override
+                public void syncLost()
+                {
+                    //no-op
+                }
             });
         }
 

src/main/java/io/github/dsheirer/gui/instrument/decoder/MDC1200Pane.java

@@ -44,6 +44,12 @@ public class MDC1200Pane extends AbstractAFSK1200Pane
                 {
                     mLog.debug("Sync Detected!");
                 }
+
+                @Override
+                public void syncLost()
+                {
+                    mLog.debug("Sync Lost!");
+                }
             });
         }
 

src/main/java/io/github/dsheirer/gui/instrument/decoder/MPT1327Pane.java

@@ -44,6 +44,12 @@ public class MPT1327Pane extends AbstractAFSK1200Pane
                 {
 //                    mLog.debug("Control Sync Detected!");
                 }
+
+                @Override
+                public void syncLost()
+                {
+                    //no-op
+                }
             });
             mDecoder.getTrafficMessageFramer().setSyncDetectListener(new ISyncDetectListener()
             {
@@ -52,6 +58,12 @@ public class MPT1327Pane extends AbstractAFSK1200Pane
                 {
 //                    mLog.debug("Traffic Sync Detected!");
                 }
+
+                @Override
+                public void syncLost()
+                {
+                    //no-op
+                }
             });
         }
 

src/main/java/io/github/dsheirer/gui/instrument/decoder/P25Phase1LSMPane.java

@@ -176,7 +176,7 @@ public class P25Phase1LSMPane extends ComplexDecoderPane
     {
         if(mPLLFrequencyLineChart == null)
         {
-            mPLLFrequencyLineChart = new DoubleLineChart( "PLL Frequency", -500, 500, 50, 40);
+            mPLLFrequencyLineChart = new DoubleLineChart( "PLL Frequency", -2500, 2500, 200, 40);
         }
 
         return mPLLFrequencyLineChart;
@@ -186,7 +186,7 @@ public class P25Phase1LSMPane extends ComplexDecoderPane
     {
         if(mSamplesPerSymbolLineChart == null)
         {
-            mSamplesPerSymbolLineChart = new DoubleLineChart( "Sample Point", 9.5, 11.5, 0.1, 40);
+            mSamplesPerSymbolLineChart = new DoubleLineChart( "Sample Point", 4.5, 7.0, 0.1, 40);
         }
 
         return mSamplesPerSymbolLineChart;

src/main/java/io/github/dsheirer/gui/instrument/decoder/Tait1200Pane.java

@@ -44,6 +44,12 @@ public class Tait1200Pane extends AbstractAFSK1200Pane
                 {
                     mLog.debug("ANI Sync Detected!");
                 }
+
+                @Override
+                public void syncLost()
+                {
+
+                }
             });
             mDecoder.getGPSMessageFramer().setSyncDetectListener(new ISyncDetectListener()
             {
@@ -52,6 +58,12 @@ public class Tait1200Pane extends AbstractAFSK1200Pane
                 {
                     mLog.debug("GPS Sync Detected!");
                 }
+
+                @Override
+                public void syncLost()
+                {
+
+                }
             });
         }
 

src/main/java/io/github/dsheirer/module/decode/p25/C4FMSymbolFilter.java

@@ -149,7 +149,7 @@ public class C4FMSymbolFilter implements Listener<ReusableBuffer>, ISourceEventL
     private static final int SAMPLE_RATE = 48000;
     private static final int SYMBOL_RATE = 4800;
 
-    /* Tracking loop gain constant */
+    /* PLLGain loop gain constant */
     private static final double K_SYMBOL_SPREAD = 0.0100;
 
     /* Constraints on symbol spreading */

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

@@ -132,7 +132,7 @@ public abstract class P25Decoder extends Decoder implements ISourceEventListener
      * issue frequency correction requests to the channel source.
      * @param sourceEvent to broadcast
      */
-    protected void broadcast(SourceEvent sourceEvent)
+    public void broadcast(SourceEvent sourceEvent)
     {
         if(mSourceEventListener != null)
         {

src/main/java/io/github/dsheirer/module/decode/p25/P25DecoderC4FM.java

@@ -23,8 +23,8 @@ import io.github.dsheirer.dsp.filter.fir.complex.ComplexFIRFilter2;
 import io.github.dsheirer.dsp.gain.ComplexFeedForwardGainControl;
 import io.github.dsheirer.dsp.psk.DQPSKDecisionDirectedDemodulator;
 import io.github.dsheirer.dsp.psk.InterpolatingSampleBuffer;
+import io.github.dsheirer.dsp.psk.pll.AdaptivePLLGainMonitor;
 import io.github.dsheirer.dsp.psk.pll.CostasLoop;
-import io.github.dsheirer.dsp.psk.pll.Tracking;
 import io.github.dsheirer.sample.buffer.ReusableComplexBuffer;
 import io.github.dsheirer.source.SourceEvent;
 import org.slf4j.Logger;
@@ -36,10 +36,12 @@ import java.util.Map;
 public class P25DecoderC4FM extends P25Decoder
 {
     private final static Logger mLog = LoggerFactory.getLogger(P25DecoderC4FM.class);
-    protected static final float SAMPLE_COUNTER_GAIN = 0.5f;
+
+    protected static final float SAMPLE_COUNTER_GAIN = 0.3f;
     protected InterpolatingSampleBuffer mInterpolatingSampleBuffer;
     protected DQPSKDecisionDirectedDemodulator mQPSKDemodulator;
     protected CostasLoop mCostasLoop;
+    protected AdaptivePLLGainMonitor mPLLGainMonitor;
     protected P25MessageFramer mMessageFramer;
     private ComplexFeedForwardGainControl mAGC = new ComplexFeedForwardGainControl(32);
     private Map<Double,float[]> mBasebandFilters = new HashMap<>();
@@ -54,7 +56,7 @@ public class P25DecoderC4FM extends P25Decoder
     public P25DecoderC4FM(AliasList aliasList)
     {
         super(4800.0, aliasList);
-        setSampleRate(48000.0);
+        setSampleRate(25000.0);
     }
 
     public void setSampleRate(double sampleRate)
@@ -64,14 +66,16 @@ public class P25DecoderC4FM extends P25Decoder
         mBasebandFilter = new ComplexFIRFilter2(getBasebandFilter());
 
         mCostasLoop = new CostasLoop(getSampleRate(), getSymbolRate());
-        mCostasLoop.setTracking(Tracking.FASTEST);
+        mPLLGainMonitor = new AdaptivePLLGainMonitor(mCostasLoop, this);
         mInterpolatingSampleBuffer = new InterpolatingSampleBuffer(getSamplesPerSymbol(), SAMPLE_COUNTER_GAIN);
 
         mQPSKDemodulator = new DQPSKDecisionDirectedDemodulator(mCostasLoop, mInterpolatingSampleBuffer);
 
-        //Message framer can issue a symbol-inversion correction request to the PLL when detected
+        //The Costas Loop receives symbol-inversion correction requests when detected.
-        mMessageFramer = new P25MessageFramer(getAliasList(), mCostasLoop);
+        //The PLL gain monitor receives sync detect/loss signals from the message framer
+        mMessageFramer = new P25MessageFramer(getAliasList(), mCostasLoop, mPLLGainMonitor);
         mMessageFramer.setListener(getMessageProcessor());
+        mMessageFramer.setSampleRate(sampleRate);
         mQPSKDemodulator.setSymbolListener(mMessageFramer);
     }
 
@@ -165,6 +169,10 @@ public class P25DecoderC4FM extends P25Decoder
                 mCostasLoop.reset();
                 setSampleRate(sourceEvent.getValue().doubleValue());
                 break;
+            case NOTIFICATION_FREQUENCY_CORRECTION_CHANGE:
+                //Reset the PLL if/when the tuner PPM changes so that we can re-lock
+                mCostasLoop.reset();
+                break;
         }
     }
 
@@ -183,5 +191,6 @@ public class P25DecoderC4FM extends P25Decoder
     public void reset()
     {
         mCostasLoop.reset();
+        mPLLGainMonitor.reset();
     }
 }

src/main/java/io/github/dsheirer/module/decode/p25/P25DecoderLSM.java

@@ -22,20 +22,17 @@ import io.github.dsheirer.dsp.filter.fir.complex.ComplexFIRFilter2;
 import io.github.dsheirer.dsp.gain.ComplexFeedForwardGainControl;
 import io.github.dsheirer.dsp.psk.DQPSKGardnerDemodulator;
 import io.github.dsheirer.dsp.psk.InterpolatingSampleBuffer;
+import io.github.dsheirer.dsp.psk.pll.AdaptivePLLGainMonitor;
 import io.github.dsheirer.dsp.psk.pll.CostasLoop;
-import io.github.dsheirer.dsp.psk.pll.Tracking;
 import io.github.dsheirer.sample.buffer.ReusableComplexBuffer;
 import io.github.dsheirer.source.SourceEvent;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 import java.util.HashMap;
 import java.util.Map;
 
 public class P25DecoderLSM extends P25Decoder
 {
-    private final static Logger mLog = LoggerFactory.getLogger(P25DecoderLSM.class);
+    protected static final float SAMPLE_COUNTER_GAIN = 0.3f;
-    protected static final float SAMPLE_COUNTER_GAIN = 0.5f;
 
     private Map<Double,float[]> mBasebandFilters = new HashMap<>();
     private ComplexFIRFilter2 mBasebandFilter;
@@ -43,6 +40,7 @@ public class P25DecoderLSM extends P25Decoder
     protected DQPSKGardnerDemodulator mQPSKDemodulator;
     protected P25MessageFramer mMessageFramer;
     protected CostasLoop mCostasLoop;
+    protected AdaptivePLLGainMonitor mPLLGainMonitor;
     protected InterpolatingSampleBuffer mInterpolatingSampleBuffer;
 
     /**
@@ -54,11 +52,12 @@ public class P25DecoderLSM extends P25Decoder
     public P25DecoderLSM(AliasList aliasList)
     {
         super(4800.0, aliasList);
-        setSampleRate(48000.0);
+        setSampleRate(25000.0);
     }
 
     /**
      * Sets or changes the channel sample rate
+     *
      * @param sampleRate in hertz
      */
     public void setSampleRate(double sampleRate)
@@ -68,14 +67,17 @@ public class P25DecoderLSM extends P25Decoder
         mBasebandFilter = new ComplexFIRFilter2(getBasebandFilter());
 
         mCostasLoop = new CostasLoop(getSampleRate(), getSymbolRate());
-        mCostasLoop.setTracking(Tracking.NORMAL);
+        mPLLGainMonitor = new AdaptivePLLGainMonitor(mCostasLoop, this);
+
         mInterpolatingSampleBuffer = new InterpolatingSampleBuffer(getSamplesPerSymbol(), SAMPLE_COUNTER_GAIN);
 
         mQPSKDemodulator = new DQPSKGardnerDemodulator(mCostasLoop, mInterpolatingSampleBuffer);
 
-        //Message framer can issue a symbol-inversion correction request to the PLL when detected
+        //The Costas Loop receives symbol-inversion correction requests when detected.
-        mMessageFramer = new P25MessageFramer(getAliasList(), mCostasLoop);
+        //The PLL gain monitor receives sync detect/loss signals from the message framer
+        mMessageFramer = new P25MessageFramer(getAliasList(), mCostasLoop, mPLLGainMonitor);
         mMessageFramer.setListener(getMessageProcessor());
+        mMessageFramer.setSampleRate(sampleRate);
         mQPSKDemodulator.setSymbolListener(mMessageFramer);
     }
 
@@ -97,13 +99,18 @@ public class P25DecoderLSM extends P25Decoder
 
     /**
      * Filters the complex buffer and returns a new reusable complex buffer with the filtered contents.
+     *
      * @param reusableComplexBuffer to filter
      * @return filtered complex buffer
      */
     protected ReusableComplexBuffer filter(ReusableComplexBuffer reusableComplexBuffer)
     {
+        //No additional filtering of the channel is currently needed, since the polyphase channelizer
+        //provides the filtering.
+        return reusableComplexBuffer;
+
         //User accounting of the incoming buffer is handled by the filter
-        return mBasebandFilter.filter(reusableComplexBuffer);
+//        return mBasebandFilter.filter(reusableComplexBuffer);
     }
 
     /**
@@ -119,6 +126,10 @@ public class P25DecoderLSM extends P25Decoder
                 setSampleRate(sourceEvent.getValue().doubleValue());
                 mCostasLoop.reset();
                 break;
+            case NOTIFICATION_FREQUENCY_CORRECTION_CHANGE:
+                //Reset the PLL if/when the tuner PPM changes so that we can re-lock
+                mCostasLoop.reset();
+                break;
         }
     }
 
@@ -129,6 +140,7 @@ public class P25DecoderLSM extends P25Decoder
     public void reset()
     {
         mCostasLoop.reset();
+        mPLLGainMonitor.reset();
     }
 
     public void dispose()
@@ -163,7 +175,7 @@ public class P25DecoderLSM extends P25Decoder
 
         if(filter == null)
         {
-            filter = FilterFactory.getLowPass(48000, 7250, 8000, 60,
+            filter = FilterFactory.getLowPass(getSampleRate(), 7250, 8000, 60,
                 WindowType.HANN, true);
 
             mBasebandFilters.put(getSampleRate(), filter);

src/main/java/io/github/dsheirer/module/decode/p25/P25MessageFramer.java

@@ -36,11 +36,11 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.ArrayList;
+import java.util.List;
 
 public class P25MessageFramer implements Listener<Dibit>
 {
-    private final static Logger mLog =
+    private final static Logger mLog = LoggerFactory.getLogger(P25MessageFramer.class);
-        LoggerFactory.getLogger(P25MessageFramer.class);
 
     /* Determines the threshold for sync pattern soft matching */
     private static final int SYNC_MATCH_THRESHOLD = 2;
@@ -49,9 +49,10 @@ public class P25MessageFramer implements Listener<Dibit>
     /* Costas Loop phase lock error correction values.  A phase lock error of
      * 90 degrees requires a correction of 1/4 of the symbol rate (1200Hz).  An
      * error of 180 degrees requires a correction of 1/2 of the symbol rate */
-    public static final double SYMBOL_FREQUENCY = 2.0d * Math.PI * 4800.0d / 48000.0d;
+    public static final double DEFAULT_SAMPLE_RATE = 25000.0;
-    public static final double PHASE_CORRECTION_90_DEGREES = SYMBOL_FREQUENCY / 4.0d;
+    public static final double FREQUENCY_PHASE_CORRECTION_90_DEGREES = 1200.0;
-    public static final double PHASE_CORRECTION_180_DEGREES = SYMBOL_FREQUENCY / 2.0d;
+    public static final double FREQUENCY_PHASE_CORRECTION_180_DEGREES = 2400.0;
+
     public static final int TSBK_BEGIN = 64;
     public static final int TSBK_CRC_START = 144;
     public static final int TSBK_END = 260;
@@ -71,9 +72,12 @@ public class P25MessageFramer implements Listener<Dibit>
     private SoftSyncDetector mPrimarySyncDetector = new SoftSyncDetector(
         FrameSync.P25_PHASE1_NORMAL.getSync(), SYNC_MATCH_THRESHOLD);
 
-    private MultiSyncPatternMatcher mMatcher = new MultiSyncPatternMatcher(48);
+    private PLLPhaseInversionDetector mInversionDetector90CW;
-    private ArrayList<P25MessageAssembler> mAssemblers =
+    private PLLPhaseInversionDetector mInversionDetector90CCW;
-        new ArrayList<P25MessageAssembler>();
+    private PLLPhaseInversionDetector mInversionDetector180;
+
+    private MultiSyncPatternMatcher mMatcher;
+    private List<P25MessageAssembler> mAssemblers = new ArrayList<P25MessageAssembler>();
 
     private Listener<Message> mListener;
     private AliasList mAliasList;
@@ -88,10 +92,13 @@ public class P25MessageFramer implements Listener<Dibit>
      * to the message length, and then broadcast that bit buffer to the registered
      * listener.
      */
-    public P25MessageFramer(AliasList aliasList)
+    public P25MessageFramer(AliasList aliasList, ISyncDetectListener syncDetectListener)
     {
         mAliasList = aliasList;
 
+        //Assign the sync detect listener to the matcher with a sync loss threshold equal to the longest message length
+        mMatcher = new MultiSyncPatternMatcher(syncDetectListener, DataUnitID.LDU1.getMessageLength(), 48);
+
         mPrimarySyncDetector.setListener(new ISyncDetectListener()
         {
             @Override
@@ -106,6 +113,12 @@ public class P25MessageFramer implements Listener<Dibit>
                     }
                 }
             }
+
+            @Override
+            public void syncLost()
+            {
+                //no-op
+            }
         });
 
         mMatcher.add(mPrimarySyncDetector);
@@ -122,25 +135,41 @@ public class P25MessageFramer implements Listener<Dibit>
         mAssemblers.add(new P25MessageAssembler());
     }
 
-    public P25MessageFramer(AliasList aliasList, IPhaseLockedLoop phaseLockedLoop)
+    public P25MessageFramer(AliasList aliasList, IPhaseLockedLoop phaseLockedLoop, ISyncDetectListener syncDetectListener)
     {
-        this(aliasList);
+        this(aliasList, syncDetectListener);
 
         if(phaseLockedLoop != null)
         {
             //Add additional sync pattern detectors to detect when we get 90/180 degree out of phase sync pattern
             //detections so that we can apply correction to the phase locked loop
-            mMatcher.add(new PLLPhaseInversionDetector(FrameSync.P25_PHASE1_ERROR_90_CCW,
+            mInversionDetector90CW = new PLLPhaseInversionDetector(FrameSync.P25_PHASE1_ERROR_90_CW,
-                phaseLockedLoop, PHASE_CORRECTION_90_DEGREES));
+                phaseLockedLoop, DEFAULT_SAMPLE_RATE, FREQUENCY_PHASE_CORRECTION_90_DEGREES);
+            mMatcher.add(mInversionDetector90CW);
 
-            mMatcher.add(new PLLPhaseInversionDetector(FrameSync.P25_PHASE1_ERROR_90_CW,
+            mInversionDetector90CCW = new PLLPhaseInversionDetector(FrameSync.P25_PHASE1_ERROR_90_CCW,
-                phaseLockedLoop, -PHASE_CORRECTION_90_DEGREES));
+                phaseLockedLoop, DEFAULT_SAMPLE_RATE, -FREQUENCY_PHASE_CORRECTION_90_DEGREES);
+            mMatcher.add(mInversionDetector90CCW);
 
-            mMatcher.add(new PLLPhaseInversionDetector(FrameSync.P25_PHASE1_ERROR_180,
+            mInversionDetector180 = new PLLPhaseInversionDetector(FrameSync.P25_PHASE1_ERROR_180,
-                phaseLockedLoop, PHASE_CORRECTION_180_DEGREES));
+                phaseLockedLoop, DEFAULT_SAMPLE_RATE, FREQUENCY_PHASE_CORRECTION_180_DEGREES);
+            mMatcher.add(mInversionDetector180);
         }
     }
 
+    /**
+     * Updates the incoming sample stream sample rate to allow the PLL phase inversion detectors to
+     * recalculate their internal phase correction values.
+     *
+     * @param sampleRate of the incoming sample stream
+     */
+    public void setSampleRate(double sampleRate)
+    {
+        mInversionDetector180.setSampleRate(sampleRate);
+        mInversionDetector90CW.setSampleRate(sampleRate);
+        mInversionDetector90CCW.setSampleRate(sampleRate);
+    }
+
     public void dispose()
     {
         for(P25MessageAssembler a : mAssemblers)
@@ -671,34 +700,46 @@ public class P25MessageFramer implements Listener<Dibit>
     }
 
     /**
-     * Sync pattern detector to listen for costas loop phase lock errors and
+     * Sync pattern detector to listen for costas loop phase lock errors and apply a phase correction to the costas
-     * apply a phase correction to the costas loop so that we don't miss any
+     * loop so that we don't miss any messages.
-     * messages.
      *
-     * When the costas loop locks with a +/- 90 degree or 180 degree phase
+     * When the costas loop locks with a +/- 90 degree or 180 degree phase error, the slicer will incorrectly apply
-     * error, the slicer will incorrectly apply the symbol pattern rotated left
+     * the symbol pattern rotated left or right by the phase error.  However, we can detect these rotated sync patterns
-     * or right by the phase error.  However, we can detect these rotated sync
+     * and apply immediate phase correction so that message processing can continue.
-     * patterns and apply immediate phase correction so that message processing
-     * can continue.
      */
     public class PLLPhaseInversionDetector extends SyncDetector
     {
+        private FrameSync mFrameSync;
         private IPhaseLockedLoop mPhaseLockedLoop;
-        private double mCorrection;
+        private double mSampleRate;
+        private double mFrequencyCorrection;
+        private double mPllCorrection;
 
-        public PLLPhaseInversionDetector(FrameSync frameSync, IPhaseLockedLoop phaseLockedLoop, double correction)
+        /**
+         * Constructs the PLL phase inversion detector.
+         *
+         * @param frameSync pattern to monitor for detecting phase inversion errors
+         * @param phaseLockedLoop to receive phase correction values
+         * @param sampleRate of the incoming sample stream
+         * @param frequencyCorrection to apply to the PLL.  Examples:
+         *      QPSK +/-90 degree correction: +/-SYMBOL RATE / 4.0
+         *      QPSK 180 degree correction: SYMBOL RATE / 2.0
+         */
+        public PLLPhaseInversionDetector(FrameSync frameSync, IPhaseLockedLoop phaseLockedLoop, double sampleRate,
+                                         double frequencyCorrection)
         {
             super(frameSync.getSync());
-
+            mFrameSync = frameSync;
             mPhaseLockedLoop = phaseLockedLoop;
-            mCorrection = correction;
+            mFrequencyCorrection = frequencyCorrection;
+            setSampleRate(sampleRate);
 
             setListener(new ISyncDetectListener()
             {
                 @Override
                 public void syncDetected()
                 {
-                    mPhaseLockedLoop.correctInversion(mCorrection);
+                    mPhaseLockedLoop.correctInversion(mPllCorrection);
 
                     /* Since we detected a sync pattern, start a message assembler */
                     for(P25MessageAssembler assembler : mAssemblers)
@@ -710,7 +751,24 @@ public class P25MessageFramer implements Listener<Dibit>
                         }
                     }
                 }
+
+                @Override
+                public void syncLost()
+                {
+                    //no-op
+                }
             });
+
+        }
+
+        /**
+         * Sets or adjusts the sample rate so that the phase inversion correction value can be recalculated.
+         * @param sampleRate
+         */
+        public void setSampleRate(double sampleRate)
+        {
+            mSampleRate = sampleRate;
+            mPllCorrection = 2.0 * Math.PI * mFrequencyCorrection / mSampleRate;
         }
     }
 }

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

@@ -31,6 +31,8 @@ public class SourceEvent
         NOTIFICATION_FREQUENCY_AND_SAMPLE_RATE_UNLOCKED,
         NOTIFICATION_FREQUENCY_CHANGE,
         NOTIFICATION_FREQUENCY_CORRECTION_CHANGE,
+        NOTIFICATION_MEASURED_FREQUENCY_ERROR,
+        NOTIFICATION_MEASURED_FREQUENCY_ERROR_SYNC_LOCKED,
         NOTIFICATION_SAMPLE_RATE_CHANGE,
         NOTIFICATION_STOP_SAMPLE_STREAM,
 
@@ -124,6 +126,14 @@ public class SourceEvent
         return mSource;
     }
 
+    /**
+     * Sets the source associated with this event
+     */
+    public void setSource(Source source)
+    {
+        mSource = source;
+    }
+
     /**
      * Indicates if this event contains an optional source
      */
@@ -189,6 +199,28 @@ public class SourceEvent
         return new SourceEvent(Event.NOTIFICATION_CHANNEL_FREQUENCY_CORRECTION_CHANGE, frequencyCorrection);
     }
 
+    /**
+     * Creates a new frequency error measurement notification event.
+     *
+     * @param frequencyError in hertz
+     */
+    public static SourceEvent frequencyErrorMeasurement(long frequencyError)
+    {
+        return new SourceEvent(Event.NOTIFICATION_MEASURED_FREQUENCY_ERROR, frequencyError);
+    }
+
+    /**
+     * Creates a new frequency error measurement notification event.  This event is different from
+     * the raw frequency error measurement and indicates that the current state of the PLL is
+     * locked and tracking the signal.
+     *
+     * @param frequencyError in hertz
+     */
+    public static SourceEvent frequencyErrorMeasurementSyncLocked(long frequencyError, String eventDescription)
+    {
+        return new SourceEvent(Event.NOTIFICATION_MEASURED_FREQUENCY_ERROR_SYNC_LOCKED, frequencyError, eventDescription);
+    }
+
     /**
      * Creates a new sample rate change event
      *
@@ -288,7 +320,7 @@ public class SourceEvent
     {
         return "SOURCE EVENT:" + mEvent +
                " VALUE:" + (mValue != null ? mValue : "(empty)") +
-               " SOURCE:" + (mSource != null ? mSource.getClass() : "(null)") +
+               " SOURCE:" + (mSource != null ? mSource.toString() : "(null)") +
                " DESCRIPTION:" + (mEventDescription != null ? mEventDescription : "");
     }
 }

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

@@ -0,0 +1,149 @@
+/*******************************************************************************
+ * 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.tuner;
+
+import io.github.dsheirer.source.SourceException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Monitors measured frequency error PPM values from the tuner and (when enabled) applies the current
+ * error measurement to the tuner controller to adjust the tuner's PPM and align the frequency value.
+ */
+public class FrequencyErrorCorrectionManager
+{
+    private final static Logger mLog = LoggerFactory.getLogger(FrequencyErrorCorrectionManager.class);
+
+    private static final double FREQUENCY_CORRECTION_ERROR_THRESHOLD = 0.4;
+    private static final long AUTO_CORRECTION_OBSERVATION_PERIOD_MILLISECONDS = 30 * 1000; //30 seconds
+    private long mObservationPeriodStart;
+    private double mPPMRequired;
+    private boolean mEnabled = true;
+    private TunerController mTunerController;
+
+    /**
+     * Constructs a frequency error correction manager for the specified tuner controller.
+     */
+    public FrequencyErrorCorrectionManager(TunerController tunerController)
+    {
+        mTunerController = tunerController;
+    }
+
+    /**
+     * Enables or disables automatic frequency PPM correction.
+     * @param enabled to true to turn on automatic PPM adjustments.
+     */
+    public void setEnabled(boolean enabled)
+    {
+        mEnabled = enabled;
+    }
+
+    /**
+     * Resets monitoring
+     */
+    public void reset()
+    {
+        mObservationPeriodStart = 0;
+        mPPMRequired = 0;
+    }
+
+    /**
+     * Applies a PPM adjustment value to the tuner's current PPM setting, when auto-correction is enabled.
+     */
+    private void applyCorrection()
+    {
+        if(mEnabled && mTunerController.hasMeasuredFrequencyError())
+        {
+            double frequencyCorrection = mTunerController.getFrequencyCorrection();
+            frequencyCorrection -= mTunerController.getPPMFrequencyError();
+
+            try
+            {
+                mLog.info("Auto-Correcting Tuner PPM to [" + frequencyCorrection + "]");
+
+                mTunerController.setFrequencyCorrection(frequencyCorrection);
+                reset();
+            }
+            catch(SourceException se)
+            {
+                mLog.error("Error while applying automatic frequency error PPM correction value: " + frequencyCorrection);
+            }
+        }
+    }
+
+    /**
+     * Updates the monitor with a new PPM frequency error measurement from the tuner.
+     */
+    public void updatePPM(double ppm)
+    {
+        if(ppm > FREQUENCY_CORRECTION_ERROR_THRESHOLD)
+        {
+            if(mObservationPeriodStart == 0)
+            {
+                mObservationPeriodStart = System.currentTimeMillis();
+                mPPMRequired = ppm;
+            }
+            else
+            {
+                if(mPPMRequired > 0)
+                {
+                    mPPMRequired = ppm;
+
+                    if(mObservationPeriodStart + AUTO_CORRECTION_OBSERVATION_PERIOD_MILLISECONDS < System.currentTimeMillis())
+                    {
+                        applyCorrection();
+                    }
+                }
+                else
+                {
+                    //Opposite polarity ppm value ... restart the timer
+                    mObservationPeriodStart = System.currentTimeMillis();
+                    mPPMRequired = ppm;
+                }
+            }
+        }
+        else if(ppm < -FREQUENCY_CORRECTION_ERROR_THRESHOLD)
+        {
+            if(mObservationPeriodStart == 0)
+            {
+                mObservationPeriodStart = System.currentTimeMillis();
+                mPPMRequired = ppm;
+            }
+            else
+            {
+                if(mPPMRequired < 0)
+                {
+                    mPPMRequired = ppm;
+
+                    if(mObservationPeriodStart + AUTO_CORRECTION_OBSERVATION_PERIOD_MILLISECONDS < System.currentTimeMillis())
+                    {
+                        applyCorrection();
+                    }
+                }
+                else
+                {
+                    //Opposite polarity ppm value ... restart the timer
+                    mObservationPeriodStart = System.currentTimeMillis();
+                    mPPMRequired = ppm;
+                }
+            }
+        }
+        else
+        {
+            reset();
+        }
+    }
+}

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

@@ -22,6 +22,8 @@ import io.github.dsheirer.source.SourceEvent;
 import io.github.dsheirer.source.tuner.TunerEvent.Event;
 import io.github.dsheirer.source.tuner.manager.ChannelSourceManager;
 import io.github.dsheirer.source.tuner.manager.TunerChannelSourceManager;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Tuner provides an interface to a software or hardware tuner controller that provides I/Q sample data coupled with a
@@ -29,9 +31,12 @@ import io.github.dsheirer.source.tuner.manager.TunerChannelSourceManager;
  */
 public abstract class Tuner implements ISourceEventProcessor
 {
+    private final static Logger mLog = LoggerFactory.getLogger(Tuner.class);
+
     private Broadcaster<TunerEvent> mTunerEventBroadcaster = new Broadcaster<>();
     private ChannelSourceManager mChannelSourceManager;
     private TunerController mTunerController;
+    private TunerFrequencyErrorMonitor mTunerFrequencyErrorMonitor;
     private String mName;
 
     /**
@@ -49,6 +54,9 @@ public abstract class Tuner implements ISourceEventProcessor
         mChannelSourceManager = new TunerChannelSourceManager(mTunerController);
         //Register to receive channel count change notifications
         mChannelSourceManager.addSourceEventListener(this::process);
+
+        mTunerFrequencyErrorMonitor = new TunerFrequencyErrorMonitor(this);
+        mTunerFrequencyErrorMonitor.start();
     }
 
     @Override
@@ -60,16 +68,23 @@ public abstract class Tuner implements ISourceEventProcessor
                 broadcast(new TunerEvent(Tuner.this, Event.CHANNEL_COUNT));
                 break;
             case NOTIFICATION_FREQUENCY_CHANGE:
-                broadcast(new TunerEvent(Tuner.this, Event.FREQUENCY));
+                broadcast(new TunerEvent(Tuner.this, Event.FREQUENCY_UPDATED));
+                break;
+            case NOTIFICATION_FREQUENCY_CORRECTION_CHANGE:
+                broadcast(new TunerEvent(Tuner.this, Event.FREQUENCY_ERROR_UPDATED));
                 break;
             case NOTIFICATION_SAMPLE_RATE_CHANGE:
-                broadcast(new TunerEvent(Tuner.this, Event.SAMPLE_RATE));
+                broadcast(new TunerEvent(Tuner.this, Event.SAMPLE_RATE_UPDATED));
                 break;
             case NOTIFICATION_FREQUENCY_AND_SAMPLE_RATE_LOCKED:
             case NOTIFICATION_FREQUENCY_AND_SAMPLE_RATE_UNLOCKED:
                 broadcast(new TunerEvent(Tuner.this, Event.LOCK_STATE_CHANGE));
                 break;
+            case NOTIFICATION_MEASURED_FREQUENCY_ERROR_SYNC_LOCKED:
+                mTunerFrequencyErrorMonitor.receive(event);
+                break;
             default:
+                mLog.debug("Unrecognized Source Event: " + event.toString());
                 break;
         }
     }

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

@@ -41,6 +41,7 @@ public abstract class TunerController implements Tunable, ISourceEventProcessor,
     private int mMiddleUnusableHalfBandwidth;
     private double mUsableBandwidthPercentage;
     private Listener<SourceEvent> mSourceEventListener;
+    private int mMeasuredFrequencyError;
 
     /**
      * Abstract tuner controller class.  The tuner controller manages frequency bandwidth and currently tuned channels
@@ -242,6 +243,46 @@ public abstract class TunerController implements Tunable, ISourceEventProcessor,
         return (int)(getUsableBandwidth() / 2);
     }
 
+    /**
+     * Current measured frequency error as received/reported from certain downstream decoders.
+      * @return measured frequency error in hertz averaged over 1-second intervals
+     */
+    public int getMeasuredFrequencyError()
+    {
+        return mMeasuredFrequencyError;
+    }
+
+    /**
+     * Indicates if this tuner controller has a non-zero measured frequency error value.
+     */
+    public boolean hasMeasuredFrequencyError()
+    {
+        return mMeasuredFrequencyError != 0;
+    }
+
+    /**
+     * Calculates the current PPM error value as measured by certain downstream decoders.
+     * @return
+     */
+    public double getPPMFrequencyError()
+    {
+        if(hasMeasuredFrequencyError())
+        {
+            return mMeasuredFrequencyError / ((double)getFrequency() / 1E6d);
+        }
+
+        return 0.0d;
+    }
+
+    /**
+     * Sets the measured frequency error average.
+     * @param measuredFrequencyError in hertz averaged over a 5 second interval.
+     */
+    public void setMeasuredFrequencyError(int measuredFrequencyError)
+    {
+        mMeasuredFrequencyError = measuredFrequencyError;
+    }
+
     /**
      * Sets the listener to be notified any time that the tuner changes frequency
      * or bandwidth/sample rate.

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

@@ -23,12 +23,13 @@ public class TunerEvent
 
     public enum Event
     {
-        ADD,
-        LOCK_STATE_CHANGE,
-        REMOVE,
         CHANNEL_COUNT,
-        FREQUENCY,
+        FREQUENCY_UPDATED,
-        SAMPLE_RATE,
+        FREQUENCY_ERROR_UPDATED,
+        LOCK_STATE_CHANGE,
+        MEASURED_FREQUENCY_ERROR_UPDATED,
+        SAMPLE_RATE_UPDATED,
+
         CLEAR_MAIN_SPECTRAL_DISPLAY,
         REQUEST_MAIN_SPECTRAL_DISPLAY,
         REQUEST_NEW_SPECTRAL_DISPLAY;

src/main/java/io/github/dsheirer/source/tuner/TunerFrequencyErrorMonitor.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.source.tuner;
+
+import io.github.dsheirer.sample.Listener;
+import io.github.dsheirer.source.SourceEvent;
+import io.github.dsheirer.util.ThreadPool;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.LinkedTransferQueue;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Monitors frequency error measurements received from certain decoders (e.g. P25) and averages those
+ * measurements over an interval period.  Averaged measurement values are applied to the tuner controller
+ * and broadcast as a TunerEvent for visual display.
+ */
+public class TunerFrequencyErrorMonitor implements Listener<SourceEvent>
+{
+    private final static Logger mLog = LoggerFactory.getLogger(TunerFrequencyErrorMonitor.class);
+    private static final int PROCESSING_INTERVAL_SECONDS = 5;
+    private LinkedTransferQueue<Integer> mMeasurementsQueue = new LinkedTransferQueue<>();
+    private List<Integer> mProcessingMeasurements = new ArrayList();
+    private ScheduledFuture<?> mTimerHandle;
+    private Tuner mTuner;
+
+    /**
+     * Constructs a monitor for the tuner argument.
+     * @param tuner to monitor for frequency error measurements
+     */
+    public TunerFrequencyErrorMonitor(Tuner tuner)
+    {
+        mTuner = tuner;
+    }
+
+    /**
+     * Primary method for receiving frequency error measurements from downstream decoders.
+     */
+    @Override
+    public void receive(SourceEvent sourceEvent)
+    {
+        if(sourceEvent.getEvent() == SourceEvent.Event.NOTIFICATION_MEASURED_FREQUENCY_ERROR_SYNC_LOCKED)
+        {
+            mMeasurementsQueue.add(sourceEvent.getValue().intValue());
+        }
+    }
+
+    /**
+     * Calculates the average frequency error measurement value from discrete measurements received from
+     * the decoders over the interval period.
+     */
+    private void process()
+    {
+        mMeasurementsQueue.drainTo(mProcessingMeasurements);
+
+        if(mProcessingMeasurements.size() > 0)
+        {
+            int sum = 0;
+
+            for(Integer measurement: mProcessingMeasurements)
+            {
+                sum += measurement;
+            }
+
+            //Note: the measurements are the frequency correction being applied to each channel to compensate
+            //for the error int the channel.  So, we report the negated value as the current error measurement
+            broadcast(-(sum / mProcessingMeasurements.size()));
+        }
+        else
+        {
+            broadcast(0);
+        }
+
+        mProcessingMeasurements.clear();
+    }
+
+    private void broadcast(int averageError)
+    {
+        mTuner.getTunerController().setMeasuredFrequencyError(averageError);
+        mTuner.broadcast(new TunerEvent(mTuner, TunerEvent.Event.MEASURED_FREQUENCY_ERROR_UPDATED));
+    }
+
+    /**
+     * Starts this monitor processing frequency error measurements received from select channel decoders
+     * and averaging those values over a 1 second interval for transmission as a tuner event.
+     */
+    public void start()
+    {
+        if(mTimerHandle == null)
+        {
+            mTimerHandle = ThreadPool.SCHEDULED.scheduleAtFixedRate(new Processor(), 0,
+                PROCESSING_INTERVAL_SECONDS, TimeUnit.SECONDS);
+        }
+    }
+
+    /**
+     * Stops this monitor
+     */
+    public void stop()
+    {
+        if(mTimerHandle != null)
+        {
+            mTimerHandle.cancel(true);
+            mTimerHandle = null;
+            broadcast(0);
+        }
+    }
+
+    /**
+     * Runnable implementation to invoke the process() method when the timer fires.
+     */
+    public class Processor implements Runnable
+    {
+        @Override
+        public void run()
+        {
+            process();
+        }
+    }
+}

src/main/java/io/github/dsheirer/source/tuner/TunerModel.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.tuner;
 
 import io.github.dsheirer.properties.SystemProperties;
@@ -31,17 +46,19 @@ public class TunerModel extends AbstractTableModel implements Listener<TunerEven
     public static final int SAMPLE_RATE = 2;
     public static final int FREQUENCY = 3;
     public static final int CHANNEL_COUNT = 4;
-    public static final int SPECTRAL_DISPLAY_MAIN = 5;
+    public static final int FREQUENCY_ERROR = 5;
-    public static final int SPECTRAL_DISPLAY_NEW = 6;
+    public static final int MEASURED_FREQUENCY_ERROR = 6;
+    public static final int SPECTRAL_DISPLAY_NEW = 7;
 
     private static final String MHZ = " MHz";
-    private static final String[] COLUMNS =
+    private static final String[] COLUMNS = {"Tuner", "ID", "Sample Rate", "Frequency", "Channels", "Current PPM",
-        {"Tuner", "ID", "Sample Rate", "Frequency", "Channels", "Spectral", "Display"};
+        "Measured Error", "Display"};
 
     private List<Tuner> mTuners = new ArrayList<>();
     private List<Listener<TunerEvent>> mTunerEventListeners = new ArrayList<>();
     private DecimalFormat mFrequencyFormat = new DecimalFormat("0.00000");
     private DecimalFormat mSampleRateFormat = new DecimalFormat("0.000");
+    private DecimalFormat mFrequencyErrorPPMFormat = new DecimalFormat("0.0");
 
     private TunerConfigurationModel mTunerConfigurationModel;
 
@@ -206,15 +223,21 @@ public class TunerModel extends AbstractTableModel implements Listener<TunerEven
                     case CHANNEL_COUNT:
                         fireTableCellUpdated(index, CHANNEL_COUNT);
                         break;
-                    case FREQUENCY:
+                    case FREQUENCY_UPDATED:
                         fireTableCellUpdated(index, FREQUENCY);
                         mTunerConfigurationModel.tunerFrequencyChanged(event.getTuner());
                         break;
-                    case SAMPLE_RATE:
+                    case FREQUENCY_ERROR_UPDATED:
+                        fireTableCellUpdated(index, FREQUENCY_ERROR);
+                        break;
+                    case MEASURED_FREQUENCY_ERROR_UPDATED:
+                        fireTableCellUpdated(index, MEASURED_FREQUENCY_ERROR);
+                        break;
+                    case SAMPLE_RATE_UPDATED:
                         fireTableCellUpdated(index, SAMPLE_RATE);
                         break;
                     case REQUEST_MAIN_SPECTRAL_DISPLAY:
-                        fireTableCellUpdated(index, SPECTRAL_DISPLAY_MAIN);
+                        fireTableCellUpdated(index, MEASURED_FREQUENCY_ERROR);
                     default:
                         break;
                 }
@@ -275,8 +298,21 @@ public class TunerModel extends AbstractTableModel implements Listener<TunerEven
                     {
                         return "0";
                     }
-                case SPECTRAL_DISPLAY_MAIN:
+                case FREQUENCY_ERROR:
-                    return "Main";
+                    double ppm = tuner.getTunerController().getFrequencyCorrection();
+                    return mFrequencyErrorPPMFormat.format(ppm);
+                case MEASURED_FREQUENCY_ERROR:
+                    if(tuner.getTunerController().hasMeasuredFrequencyError())
+                    {
+                        StringBuilder sb = new StringBuilder();
+                        sb.append(tuner.getTunerController().getMeasuredFrequencyError());
+                        sb.append("Hz (");
+                        sb.append(mFrequencyErrorPPMFormat.format(tuner.getTunerController().getPPMFrequencyError()));
+                        sb.append("ppm)");
+                        return sb.toString();
+                    }
+
+                    return "";
                 case SPECTRAL_DISPLAY_NEW:
                     return "New";
                 default:

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

@@ -85,9 +85,12 @@ public class TunerViewPanel extends JPanel
                 if(!event.getValueIsAdjusting())
                 {
                     int row = mTunerTable.getSelectedRow();
-                    int modelRow = mTunerTable.convertRowIndexToModel(row);
 
-                    mTunerEditor.setItem(mTunerModel.getTuner(modelRow));
+                    if(row >= 0)
+                    {
+                        int modelRow = mTunerTable.convertRowIndexToModel(row);
+                        mTunerEditor.setItem(mTunerModel.getTuner(modelRow));
+                    }
                 }
             }
         });
@@ -127,20 +130,7 @@ public class TunerViewPanel extends JPanel
             {
                 int column = mTunerTable.columnAtPoint(e.getPoint());
 
-                if(column == TunerModel.SPECTRAL_DISPLAY_MAIN)
+                if(column == TunerModel.SPECTRAL_DISPLAY_NEW)
-                {
-                    int tableRow = mTunerTable.rowAtPoint(e.getPoint());
-                    int modelRow = mTunerTable.convertRowIndexToModel(tableRow);
-
-                    Tuner tuner = mTunerModel.getTuner(modelRow);
-
-                    if(tuner != null)
-                    {
-                        mTunerModel.broadcast(new TunerEvent(tuner,
-                            Event.REQUEST_MAIN_SPECTRAL_DISPLAY));
-                    }
-                }
-                else if(column == TunerModel.SPECTRAL_DISPLAY_NEW)
                 {
                     int tableRow = mTunerTable.rowAtPoint(e.getPoint());
                     int modelRow = mTunerTable.convertRowIndexToModel(tableRow);
@@ -157,9 +147,7 @@ public class TunerViewPanel extends JPanel
         });
 
         TableCellRenderer renderer = new LinkCellRenderer();
-
+        mTunerTable.getColumnModel().getColumn(TunerModel.SPECTRAL_DISPLAY_NEW).setCellRenderer(renderer);
-        mTunerTable.getColumnModel().getColumn(5).setCellRenderer(renderer);
-        mTunerTable.getColumnModel().getColumn(6).setCellRenderer(renderer);
 
         JScrollPane listScroller = new JScrollPane(mTunerTable);
         listScroller.setPreferredSize(new Dimension(400, 20));
@@ -188,15 +176,7 @@ public class TunerViewPanel extends JPanel
                 value, isSelected, hasFocus, row, column);
 
             label.setForeground(Color.BLUE.brighter());
-
+            label.setToolTipText("Show this tuner in a new spectral display");
-            if(column == TunerModel.SPECTRAL_DISPLAY_MAIN)
-            {
-                label.setToolTipText("Show this tuner in the main spectral display");
-            }
-            else if(column == TunerModel.SPECTRAL_DISPLAY_NEW)
-            {
-                label.setToolTipText("Show this tuner in a new spectral display");
-            }
 
             return label;
         }

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

@@ -181,6 +181,15 @@ public abstract class TunerChannelSource extends ComplexSource implements ISourc
             case NOTIFICATION_SAMPLE_RATE_CHANGE:
                 setSampleRate(sourceEvent.getValue().doubleValue());
                 break;
+            case NOTIFICATION_MEASURED_FREQUENCY_ERROR:
+                //Ignore these raw frequency measurement errors.  We're only interested in the measurements
+                //that occur when the channel state indicates that we're sync-locked.
+                break;
+            case NOTIFICATION_MEASURED_FREQUENCY_ERROR_SYNC_LOCKED:
+                //Rebroadcast this measurement event so the producer can process it
+                sourceEvent.setSource(this);
+                broadcastProducerSourceEvent(sourceEvent);
+                break;
             //Request events from the consumer
             case REQUEST_CHANNEL_FREQUENCY_CORRECTION_CHANGE:
                 setChannelFrequencyCorrection(sourceEvent.getValue().longValue());

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

@@ -434,8 +434,8 @@ public class TunerChannelSourceManager extends ChannelSourceManager
                 catch(IllegalArgumentException iae)
                 {
                     //Center frequency calculation failed
-                    mLog.debug("Couldn't calculate new tuner center frequency for new tuner channel [" +
+//                    mLog.debug("Couldn't calculate new tuner center frequency for new tuner channel [" +
-                        tunerChannel + "] unable to allocate new tuner channel");
+//                        tunerChannel + "] unable to allocate new tuner channel");
                 }
             }
         }
@@ -459,6 +459,11 @@ public class TunerChannelSourceManager extends ChannelSourceManager
                 //when the polyphase manager has channels allocated
                 mTunerController.setLocked(getTunerChannelCount() > 0);
                 break;
+            case NOTIFICATION_MEASURED_FREQUENCY_ERROR_SYNC_LOCKED:
+                //Rebroadcast these frequency measurement errors to the tuner and tuner controller
+                //for display and/or correction
+                broadcast(sourceEvent);
+                break;
             default:
                 mLog.info("Unrecognized source event: " + sourceEvent);
                 break;

src/main/java/io/github/dsheirer/source/tuner/rtl/RTL2832TunerController.java

@@ -51,12 +51,11 @@ public abstract class RTL2832TunerController extends USBTunerController
     private final static Logger mLog = LoggerFactory.getLogger(RTL2832TunerController.class);
 
     public final static int TWO_TO_22_POWER = 4194304;
-
+    public final static int USB_TRANSFER_BUFFER_SIZE_HIGH_SAMPLE_RATE = 131072;
-    public final static int USB_TRANSFER_BUFFER_SIZE = 131072;
+    public final static int USB_TRANSFER_BUFFER_SIZE_LOW_SAMPLE_RATE = 8192;
     public final static byte USB_INTERFACE = (byte) 0x0;
     public final static byte CONTROL_ENDPOINT_IN = (byte) (LibUsb.ENDPOINT_IN | LibUsb.REQUEST_TYPE_VENDOR);
     public final static byte CONTROL_ENDPOINT_OUT = (byte) (LibUsb.ENDPOINT_OUT | LibUsb.REQUEST_TYPE_VENDOR);
-
     public final static long TIMEOUT_US = 1000000l; //uSeconds
     public final static byte REQUEST_ZERO = (byte) 0;
     public final static byte EEPROM_ADDRESS = (byte) 0xA0;
@@ -155,7 +154,7 @@ public abstract class RTL2832TunerController extends USBTunerController
         String deviceName = getTunerType().getLabel() + " " + getUniqueID();
 
         mUSBTransferProcessor = new RTL2832USBTransferProcessor(deviceName, mDeviceHandle, mNativeBufferConverter,
-            USB_TRANSFER_BUFFER_SIZE);
+            USB_TRANSFER_BUFFER_SIZE_HIGH_SAMPLE_RATE);
     }
 
     @Override
@@ -985,6 +984,18 @@ public abstract class RTL2832TunerController extends USBTunerController
         mSampleRate = sampleRate;
 
         mFrequencyController.setSampleRate(sampleRate.getRate());
+
+        if(mUSBTransferProcessor != null)
+        {
+            if(sampleRate.getRate() > 300000)
+            {
+                mUSBTransferProcessor.setBufferSize(USB_TRANSFER_BUFFER_SIZE_HIGH_SAMPLE_RATE);
+            }
+            else
+            {
+                mUSBTransferProcessor.setBufferSize(USB_TRANSFER_BUFFER_SIZE_LOW_SAMPLE_RATE);
+            }
+        }
     }
 
     public void setSampleRateFrequencyCorrection(int ppm) throws SourceException
@@ -1220,23 +1231,29 @@ public abstract class RTL2832TunerController extends USBTunerController
     public enum SampleRate
     {
         /* Note: sample rates below 1.0MHz are subject to aliasing */
+        RATE_0_230MHZ(0x1F40, 230400, "0.230 MHz"),
         RATE_0_240MHZ(0x1E00, 240000, "0.240 MHz"),
+        RATE_0_256MHZ(0x1C20, 256000, "0.256 MHz"),
         RATE_0_288MHZ(0x1900, 288000, "0.288 MHz"),
+        RATE_0_300MHZ(0x1800, 300000, "0.300 MHz"),
         RATE_0_960MHZ(0x0780, 960000, "0.960 MHz"),
+        RATE_1_024MHZ(0x0708, 1024000, "1.024 MHz"),
         RATE_1_200MHZ(0x0600, 1200000, "1.200 MHz"),
         RATE_1_440MHZ(0x0500, 1440000, "1.440 MHz"),
-        RATE_1_920MHZ(0x03C0, 2016000, "2.016 MHz"),
+        RATE_1_600MHZ(0x0480, 1600000, "1.600 MHz"),
-        RATE_2_304MHZ(0x0320, 2208000, "2.208 MHz"),
+        RATE_1_800MHZ(0x0480, 1800000, "1.800 MHz"),
+        RATE_1_920MHZ(0x03C0, 1920000, "1.920 MHz"),
+        RATE_2_048MHZ(0x0384, 2048000, "2.048 MHz"),
+        RATE_2_304MHZ(0x0320, 2304000, "2.304 MHz"),
         RATE_2_400MHZ(0x0300, 2400000, "2.400 MHz"),
+        RATE_2_560MHZ(0x02D0, 2560000, "2.560 MHz"),
         RATE_2_880MHZ(0x0280, 2880000, "2.880 MHz");
 
         private int mRatioHigh;
         private int mRate;
         private String mLabel;
 
-        private SampleRate(int ratioHigh,
+        private SampleRate(int ratioHigh, int rate, String label)
-                           int rate,
-                           String label)
         {
             mRatioHigh = ratioHigh;
             mRate = rate;
@@ -1297,7 +1314,7 @@ public abstract class RTL2832TunerController extends USBTunerController
         private int mCheckAddress;
         private int mCheckValue;
 
-        private TunerTypeCheck(int i2c, int address, int value)
+        TunerTypeCheck(int i2c, int address, int value)
         {
             mI2CAddress = i2c;
             mCheckAddress = address;

src/main/java/io/github/dsheirer/source/tuner/rtl/e4k/E4KTunerController.java

@@ -253,7 +253,7 @@ public class E4KTunerController extends RTL2832TunerController
         String deviceName = getTunerType().getLabel() + " " + getUniqueID();
 
         mUSBTransferProcessor = new RTL2832USBTransferProcessor(deviceName, mDeviceHandle, mNativeBufferConverter,
-            USB_TRANSFER_BUFFER_SIZE);
+            USB_TRANSFER_BUFFER_SIZE_HIGH_SAMPLE_RATE);
     }
 
     @Override

src/main/java/io/github/dsheirer/source/tuner/rtl/r820t/R820TTunerConfiguration.java

@@ -30,6 +30,7 @@ public class R820TTunerConfiguration extends TunerConfiguration
     private R820TTunerController.R820TVGAGain mVGAGain = R820TTunerController.R820TVGAGain.GAIN_210;
     private double mFrequencyCorrection = 0.0d;
     private RTL2832TunerController.SampleRate mSampleRate = RTL2832TunerController.SampleRate.RATE_2_400MHZ;
+    private boolean mAutoPPMCorrection = true;
 
     /**
      * Default constructor for JAXB
@@ -115,4 +116,23 @@ public class R820TTunerConfiguration extends TunerConfiguration
     {
         mSampleRate = sampleRate;
     }
+
+    /**
+     * Indicates if automatic correction of PPM from measured frequency error is enabled/disabled.
+     * @return true if auto-correction is enabled.
+     */
+    @JacksonXmlProperty(isAttribute = true, localName = "auto_ppm_correction_enabled")
+    public boolean getAutoPPMCorrectionEnabled()
+    {
+        return mAutoPPMCorrection;
+    }
+
+    /**
+     * Sets the enabled state for auto-correction of PPM from measured frequency error values.
+     * @param enabled
+     */
+    public void setAutoPPMCorrectionEnabled(boolean enabled)
+    {
+        mAutoPPMCorrection = enabled;
+    }
 }

src/main/java/io/github/dsheirer/source/tuner/rtl/r820t/R820TTunerController.java

@@ -23,6 +23,7 @@
 package io.github.dsheirer.source.tuner.rtl.r820t;
 
 import io.github.dsheirer.source.SourceException;
+import io.github.dsheirer.source.tuner.FrequencyErrorCorrectionManager;
 import io.github.dsheirer.source.tuner.TunerType;
 import io.github.dsheirer.source.tuner.configuration.TunerConfiguration;
 import io.github.dsheirer.source.tuner.rtl.RTL2832TunerController;
@@ -33,7 +34,6 @@ import org.usb4java.DeviceDescriptor;
 import org.usb4java.LibUsb;
 import org.usb4java.LibUsbException;
 
-import javax.swing.JPanel;
 import javax.usb.UsbException;
 import java.nio.ByteBuffer;
 
@@ -43,7 +43,7 @@ public class R820TTunerController extends RTL2832TunerController
 
     public static final long MIN_FREQUENCY = 3180000;
     public static final long MAX_FREQUENCY = 1782030000;
-    public static final double USABLE_BANDWIDTH_PERCENT = 1.0;
+    public static final double USABLE_BANDWIDTH_PERCENT = 0.98;
     public static final int DC_SPIKE_AVOID_BUFFER = 5000;
 
     public static final int R820T_IF_FREQUENCY = 3570000;
@@ -70,12 +70,36 @@ public class R820TTunerController extends RTL2832TunerController
             0x6C, 0x83, 0x80, 0x00, 0x0F, 0x00, 0xC0, 0x30,
             0x48, 0xCC, 0x60, 0x00, 0x54, 0xAE, 0x4A, 0xC0};
 
-    private JPanel mEditor;
+    public FrequencyErrorCorrectionManager mFrequencyErrorCorrectionManager;
 
     public R820TTunerController(Device device, DeviceDescriptor deviceDescriptor) throws SourceException
     {
         super(device, deviceDescriptor, MIN_FREQUENCY, MAX_FREQUENCY, DC_SPIKE_AVOID_BUFFER,
             USABLE_BANDWIDTH_PERCENT);
+
+        mFrequencyErrorCorrectionManager = new FrequencyErrorCorrectionManager(this);
+    }
+
+    /**
+     * Manager for applying automatic frequency error PPM adjustments to the tuner controller based on
+     * frequency error measurements received from certain downstream decoders (e.g. P25).
+     * @return manager
+     */
+    public FrequencyErrorCorrectionManager getFrequencyErrorCorrectionManager()
+    {
+        return mFrequencyErrorCorrectionManager;
+    }
+
+    /**
+     * Overrides updates for measured frequency error so that the updates can also be applied to the
+     * frequency error correction manager for automatic PPM updating.
+     * @param measuredFrequencyError in hertz averaged over a 5 second interval.
+     */
+    @Override
+    public void setMeasuredFrequencyError(int measuredFrequencyError)
+    {
+        super.setMeasuredFrequencyError(measuredFrequencyError);
+        getFrequencyErrorCorrectionManager().updatePPM(getPPMFrequencyError());
     }
 
     @Override
@@ -106,6 +130,8 @@ public class R820TTunerController extends RTL2832TunerController
                 double correction = config.getFrequencyCorrection();
                 setFrequencyCorrection(correction);
 
+                getFrequencyErrorCorrectionManager().setEnabled(config.getAutoPPMCorrectionEnabled());
+
                 R820TGain masterGain = config.getMasterGain();
                 setGain(masterGain, true);
 

src/main/java/io/github/dsheirer/source/tuner/rtl/r820t/R820TTunerEditor.java

@@ -33,6 +33,7 @@ import org.slf4j.LoggerFactory;
 import org.usb4java.LibUsbException;
 
 import javax.swing.JButton;
+import javax.swing.JCheckBox;
 import javax.swing.JComboBox;
 import javax.swing.JLabel;
 import javax.swing.JOptionPane;
@@ -64,6 +65,7 @@ public class R820TTunerEditor extends TunerConfigurationEditor
     private JButton mTunerInfo;
     private JComboBox<SampleRate> mComboSampleRate;
     private JSpinner mFrequencyCorrection;
+    private JCheckBox mAutoPPMEnabled;
     private JComboBox<R820TGain> mComboMasterGain;
     private JComboBox<R820TMixerGain> mComboMixerGain;
     private JComboBox<R820TLNAGain> mComboLNAGain;
@@ -202,6 +204,22 @@ public class R820TTunerEditor extends TunerConfigurationEditor
         add(new JLabel("PPM:"));
         add(mFrequencyCorrection);
 
+        add(new JLabel("")); //Space filler
+        add(new JLabel("")); //Space filler
+        add(new JLabel("")); //Space filler
+        mAutoPPMEnabled = new JCheckBox("PPM Auto-Correction");
+        mAutoPPMEnabled.addActionListener(new ActionListener()
+        {
+            @Override
+            public void actionPerformed(ActionEvent e)
+            {
+                boolean enabled = mAutoPPMEnabled.isSelected();
+                mController.getFrequencyErrorCorrectionManager().setEnabled(enabled);
+                save();
+            }
+        });
+        add(mAutoPPMEnabled);
+
         add(new JSeparator(JSeparator.HORIZONTAL), "span,grow");
 
         /**
@@ -435,6 +453,11 @@ public class R820TTunerEditor extends TunerConfigurationEditor
             mFrequencyCorrection.setEnabled(enabled);
         }
 
+        if(mAutoPPMEnabled.isEnabled() != enabled)
+        {
+            mAutoPPMEnabled.setEnabled(enabled);
+        }
+
         updateSampleRateToolTip();
 
         if(mController.isLocked())
@@ -524,6 +547,8 @@ public class R820TTunerEditor extends TunerConfigurationEditor
                 .getModel()).getNumber().doubleValue();
             config.setFrequencyCorrection(value);
 
+            config.setAutoPPMCorrectionEnabled(mAutoPPMEnabled.isSelected());
+
             config.setSampleRate((SampleRate)mComboSampleRate.getSelectedItem());
 
             R820TGain gain = (R820TGain)mComboMasterGain.getSelectedItem();
@@ -560,6 +585,7 @@ public class R820TTunerEditor extends TunerConfigurationEditor
                 setControlsEnabled(true);
                 mConfigurationName.setText(config.getName());
                 mFrequencyCorrection.setValue(config.getFrequencyCorrection());
+                mAutoPPMEnabled.setSelected(config.getAutoPPMCorrectionEnabled());
                 mComboSampleRate.setSelectedItem(config.getSampleRate());
                 mComboMasterGain.setSelectedItem(config.getMasterGain());
                 mComboMixerGain.setSelectedItem(config.getMixerGain());

src/main/java/io/github/dsheirer/source/tuner/usb/USBTransferProcessor.java

@@ -86,6 +86,32 @@ public class USBTransferProcessor implements TransferCallback
         mBufferSize = bufferSize;
     }
 
+    /**
+     * Modifies the usb transfer buffer size used for transfering native byte buffers from the
+     * USB device.  Note: changing the buffer size while the transfer processor is running causes
+     * the transfer to stop momentarily while the existing buffers are destroyed and new buffers
+     * with the correct size are recreated.
+     *
+     * Note: this method is not thread safe.  Ensure that no other threads invoke stop() or start()
+     * while a buffer size change is in progress.
+     *
+     * @param bufferSize to use for native usb buffer transfers
+     */
+    public void setBufferSize(int bufferSize)
+    {
+        if(bufferSize % 2 == 1)
+        {
+            throw new IllegalArgumentException("Buffer size must be a multiple of 2 for complex samples");
+        }
+
+        if(mBufferSize != bufferSize)
+        {
+            stop();
+            mBufferSize = bufferSize;
+            start();
+        }
+    }
+
     /**
      * Start USB transfer buffer processing.  Subsequent calls to this method after started will be ignored.
      */

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

@@ -217,7 +217,8 @@ public class ComplexWaveSource extends ComplexSource implements IControllableFil
                 float[] samples = ConversionUtils.convertFromSigned16BitSamples(buffer);
 
                 ReusableComplexBuffer reusableBuffer = mReusableComplexBufferQueue.getBuffer(samples.length);
-                reusableBuffer.reloadFrom(samples, System.currentTimeMillis());
+                System.arraycopy(samples, 0, reusableBuffer.getSamples(), 0, samples.length);
+                reusableBuffer.setTimestamp(System.currentTimeMillis());
                 mListener.receive(reusableBuffer);
             }
         }

src/main/java/io/github/dsheirer/spectrum/ShowTunerMenuItem.java

@@ -15,6 +15,7 @@
  ******************************************************************************/
 package io.github.dsheirer.spectrum;
 
+import io.github.dsheirer.properties.SystemProperties;
 import io.github.dsheirer.source.tuner.Tuner;
 
 import javax.swing.JMenuItem;
@@ -44,6 +45,8 @@ public class ShowTunerMenuItem extends JMenuItem
                     public void run()
                     {
                         mSpectralDisplayPanel.showTuner(mTuner);
+                        SystemProperties properties = SystemProperties.getInstance();
+                        properties.set(SpectralDisplayPanel.SPECTRAL_DISPLAY_ENABLED, true);
                     }
                 });
             }

src/main/java/io/github/dsheirer/spectrum/WaterfallPanel.java

@@ -455,7 +455,10 @@ public class WaterfallPanel extends JPanel implements DFTResultsListener,
             @Override
             public void run()
             {
-                mMemoryImageSource.newPixels(mPixels, mColorModel, 0, mDFTSize);
+                if(mMemoryImageSource != null)
+                {
+                    mMemoryImageSource.newPixels(mPixels, mColorModel, 0, mDFTSize);
+                }
             }
         });
     }