Resolves #680 Audio Do Not Monitor is not working. Adds audio segment drop tone to indicate that an audio playback is dropped because the do not monitor setting was applied after the audio segment started. (#681)

Co-authored-by: Denny <denny@denny-desktop>

src/main/java/io/github/dsheirer/audio/playback/AudioOutput.java

@@ -85,6 +85,8 @@ public abstract class AudioOutput implements LineListener, Listener<IdentifierUp
     private IntegerProperty mAudioPriority = new SimpleIntegerProperty(Priority.DEFAULT_PRIORITY);
     private ByteBuffer mAudioSegmentStartTone;
     private ByteBuffer mAudioSegmentPreemptTone;
+    private ByteBuffer mAudioSegmentDropTone;
+    private boolean mRunning = false;
 
     /**
      * Single audio channel playback with automatic starting and stopping of the
@@ -147,9 +149,9 @@ public abstract class AudioOutput implements LineListener, Listener<IdentifierUp
                             mixer.getMixerInfo().getName() + " | " + getChannelName() + "]");
                     }
 
-					//Run the queue processor task every 250 milliseconds or 4 times a second
+					//Run the queue processor task every 100 milliseconds or 10 times a second
                     mProcessorFuture = ThreadPool.SCHEDULED.scheduleAtFixedRate(new AudioSegmentProcessor(),
-                        0, 250, TimeUnit.MILLISECONDS);
+                        0, 100, TimeUnit.MILLISECONDS);
                 }
 
                 mAudioStartEvent = new AudioEvent(AudioEvent.Type.AUDIO_STARTED, getChannelName());
@@ -255,12 +257,13 @@ public abstract class AudioOutput implements LineListener, Listener<IdentifierUp
     }
 
     /**
-     * Updates audio segment start and preempt tone insertion clips
+     * Updates audio segment start, drop and preempt tone insertion clips
      */
     private void updateToneInsertionAudioClips()
     {
         mAudioSegmentStartTone = null;
         mAudioSegmentPreemptTone = null;
+        mAudioSegmentDropTone = null;
 
         float[] start = mUserPreferences.getPlaybackPreference().getStartTone();
 
@@ -275,6 +278,13 @@ public abstract class AudioOutput implements LineListener, Listener<IdentifierUp
         {
             mAudioSegmentPreemptTone = convert(preempt);
         }
+
+        float[] drop = mUserPreferences.getPlaybackPreference().getDropTone();
+
+        if(drop != null)
+        {
+            mAudioSegmentDropTone = convert(drop);
+        }
     }
 
     /**
@@ -310,6 +320,15 @@ public abstract class AudioOutput implements LineListener, Listener<IdentifierUp
         return mAudioSegmentPreemptTone;
     }
 
+    /**
+     * Generates a tone indicating that the current audio segment playback has been dropped because the audio segment
+     * has been flagged as Do Not Monitor after playback has started.
+     */
+    private ByteBuffer getAudioSegmentDropTone()
+    {
+        return mAudioSegmentDropTone;
+    }
+
     /**
      * Writes the audio buffer data to the source data line.  If the data line is not currently playing, write as
      * much of the buffer to the data line as will fit, start the dataline, and then finish writing the residual
@@ -362,8 +381,18 @@ public abstract class AudioOutput implements LineListener, Listener<IdentifierUp
 
             try
             {
+                //Remove an assigned audio segment that's subsequently flagged as do not monitor before playback
+                if(mNextAudioSegment.isDoNotMonitor())
+                {
+                    mNextAudioSegment = null;
+
+                    if(mCurrentAudioSegment == null)
+                    {
+                        mEmptyProperty.set(true);
+                    }
+                }
                 //For linked audio segments, allow the linked segment to complete first before assigning the next
-                if(mNextAudioSegment.isLinked())
+                else if(mNextAudioSegment.isLinked())
                 {
                     if(mCurrentAudioSegment == null)
                     {
@@ -427,10 +456,15 @@ public abstract class AudioOutput implements LineListener, Listener<IdentifierUp
 
         if(mCurrentAudioSegment != null)
         {
-            //Check for completed audio segment
-            if(mCurrentAudioSegment.completeProperty().get() &&
-               mCurrentBufferIndex >= mCurrentAudioSegment.getAudioBufferCount())
+            //Check for completed audio segment or a segment flagged as Do Not Monitor
+            if(mCurrentAudioSegment.isDoNotMonitor() || (mCurrentAudioSegment.completeProperty().get() &&
+               mCurrentBufferIndex >= mCurrentAudioSegment.getAudioBufferCount()))
             {
+                if(mCurrentAudioSegment.isDoNotMonitor())
+                {
+                    playAudio(getAudioSegmentDropTone());
+                }
+
                 dispose(mCurrentAudioSegment);
                 mCurrentAudioSegment = null;
 
@@ -455,7 +489,8 @@ public abstract class AudioOutput implements LineListener, Listener<IdentifierUp
             //while processing, exit the loop so that we can evaluate the next for higher priority preempt.  If the next
             //segment is a linked segment, ignore it so that we can close out the current segment.
             while((mNextAudioSegment == null || mNextAudioSegment.isLinked()) &&
-                   mCurrentBufferIndex < mCurrentAudioSegment.getAudioBufferCount())
+                   mCurrentBufferIndex < mCurrentAudioSegment.getAudioBufferCount() &&
+                   !mCurrentAudioSegment.isDoNotMonitor())
             {
                 float[] audioBuffer = mCurrentAudioSegment.getAudioBuffers().get(mCurrentBufferIndex++);
 
@@ -595,6 +630,7 @@ public abstract class AudioOutput implements LineListener, Listener<IdentifierUp
         if(mCanProcessAudio && !mOutput.isRunning() && mOutput.available() <= mBufferStartThreshold)
         {
             mOutput.start();
+            mRunning = true;
         }
     }
 
@@ -606,11 +642,26 @@ public abstract class AudioOutput implements LineListener, Listener<IdentifierUp
      */
     private void checkStop()
     {
-        if(mCanProcessAudio && mOutput.isRunning() && mOutput.available() >= mBufferStopThreshold)
+        if(mRunning)
         {
-            mOutput.drain();
-            mOutput.stop();
-            broadcast(null);
+            //If the output buffer falls below the threshold then drain the output and stop playback
+            if(mOutput.isRunning() && mOutput.available() >= mBufferStopThreshold)
+            {
+                mOutput.drain();
+                mOutput.stop();
+                mRunning = false;
+            }
+            //If output playback stopped on its own because the buffer emptied, then cleanup
+            else if(!mOutput.isRunning())
+            {
+                mRunning = false;
+            }
+
+            //If we stopped audio playback, broadcast a null identifier to clear the gui panel
+            if(!mRunning)
+            {
+                broadcast(null);
+            }
         }
     }