#30 - WIP Streaming audio support. Adds Shoutcast V1 handler.

src/audio/broadcast/Broadcaster.java

@@ -0,0 +1,205 @@
+/*******************************************************************************
+ * sdrtrunk
+ * Copyright (C) 2014-2016 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 audio.broadcast;
+
+import audio.AudioPacket;
+import audio.IAudioPacketListener;
+import audio.broadcast.configuration.BroadcastConfiguration;
+import audio.broadcast.handler.BroadcastHandler;
+import audio.broadcast.handler.BroadcastState;
+import controller.ThreadPoolManager;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import sample.Listener;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.LinkedTransferQueue;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class Broadcaster implements IAudioPacketListener, Listener<AudioPacket>
+{
+    private final static Logger mLog = LoggerFactory.getLogger( Broadcaster.class );
+
+    private ThreadPoolManager mThreadPoolManager;
+    private ScheduledFuture mScheduledTask;
+    private AudioQueueProcessor mAudioQueueProcessor;
+    private LinkedTransferQueue<AudioPacket> mAudioQueue = new LinkedTransferQueue<>();
+    private BroadcastHandler mBroadcastHandler;
+    private boolean mEnabled = true;
+
+    /**
+     * Broadcaster for sending broadcast audio to a remote broadcast server.
+     */
+    public Broadcaster(ThreadPoolManager threadPoolManager, BroadcastHandler broadcastHandler)
+    {
+        mThreadPoolManager = threadPoolManager;
+        mBroadcastHandler = broadcastHandler;
+        mAudioQueueProcessor = new AudioQueueProcessor();
+
+        //Add broadcast state listener to stop processing if we have an error
+        mBroadcastHandler.addListener(new BroadcastStateMonitor());
+    }
+
+    /**
+     * Broadcast configuration used by this broadcaster
+     */
+    public BroadcastConfiguration getBroadcastConfiguration()
+    {
+        return mBroadcastHandler.getBroadcastConfiguration();
+    }
+
+    /**
+     * Current state of the broadcaster's connection with the remote server
+     */
+    public BroadcastState getBroadcastState()
+    {
+        return mBroadcastHandler.getBroadcastState();
+    }
+
+    /**
+     * Registers the listener to receive broadcast state changes
+     */
+    public void addListener(Listener<BroadcastState> listener)
+    {
+        mBroadcastHandler.addListener(listener);
+    }
+
+    /**
+     * Removes the listener from receiving broadcast state changes
+     */
+    public void removeListener(Listener<BroadcastState> listener)
+    {
+        mBroadcastHandler.removeListener(listener);
+    }
+
+    /**
+     * IAudioPacketListener interface method
+     */
+    @Override
+    public Listener<AudioPacket> getAudioPacketListener()
+    {
+        return this;
+    }
+
+    /**
+     * Disconnects the broadcaster and halts all broadcasting.
+     */
+    public void stop()
+    {
+        mEnabled = false;
+        stopProcessor();
+        mBroadcastHandler.disconnect();
+    }
+
+    /**
+     * Pauses the broadcaster.
+     * @param paused set to true to pause and false to continue
+     */
+    public void setPaused(boolean paused)
+    {
+        if(mEnabled)
+        {
+            mBroadcastHandler.setPaused(paused);
+        }
+    }
+
+    /**
+     * Primary audio packet input method.  Audio packets are queued and then processed by the underlying broadcast
+     * handler for broadcast to the remote server.
+     */
+    public void receive(AudioPacket packet)
+    {
+        if(mEnabled)
+        {
+            startProcessor();
+            mAudioQueue.add(packet);
+        }
+    }
+
+    /**
+     * Starts the audio queue processor.  The audio packet queue is serviced every 100 milliseconds.  Subsequent calls
+     * to this method once running are ignored.
+     */
+    private void startProcessor()
+    {
+        if(mEnabled && mScheduledTask == null)
+        {
+            if(mThreadPoolManager != null)
+            {
+                mScheduledTask = mThreadPoolManager.scheduleFixedRate(ThreadPoolManager.ThreadType.AUDIO_PROCESSING,
+                        mAudioQueueProcessor, 100, TimeUnit.MILLISECONDS );
+            }
+        }
+    }
+
+    /**
+     * Stops the audio queue processor
+     */
+    private void stopProcessor()
+    {
+        if(mThreadPoolManager != null && mScheduledTask != null)
+        {
+            mThreadPoolManager.cancel(mScheduledTask);
+        }
+    }
+
+    /**
+     * Monitors the broadcast handler for error state and halts audio broadcasting
+     */
+    public class BroadcastStateMonitor implements Listener<BroadcastState>
+    {
+        @Override
+        public void receive(BroadcastState broadcastState)
+        {
+            if(broadcastState.isErrorState())
+            {
+                stop();
+            }
+        }
+    }
+
+    /**
+     * Processes audio packets from the audio packet queue and broadcasts the audio
+     */
+    public class AudioQueueProcessor implements Runnable
+    {
+        private AtomicBoolean mProcessing = new AtomicBoolean();
+
+        @Override
+        public void run()
+        {
+            if(mProcessing.compareAndSet(false, true))
+            {
+                List<AudioPacket> audioPackets = new ArrayList<>();
+
+                mAudioQueue.drainTo(audioPackets);
+
+                if(!audioPackets.isEmpty())
+                {
+                    mBroadcastHandler.broadcast(audioPackets);
+                }
+
+                mProcessing.set(false);
+            }
+        }
+    }
+}