Add AudioPlayer thread for playing audio samples from a queue

This thread will be used for playing audio samples. The samples
will be provided by a blocking queue.

It is assumed that the configuration of the passed AudioTrack and
the samples from the blocking queue are compatible.

src/protect/babymonitor/AudioPlayer.java

@@ -0,0 +1,67 @@
+/**
+ * This file is part of the Protect Baby Monitor.
+ *
+ * Protect Baby Monitor 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.
+ *
+ * Protect Baby Monitor 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 Protect Baby Monitor. If not, see <http://www.gnu.org/licenses/>.
+ */
+package protect.babymonitor;
+
+import java.util.concurrent.BlockingQueue;
+
+import android.media.AudioTrack;
+import android.util.Log;
+
+public class AudioPlayer implements Runnable
+{
+    final String TAG = "BabyMonitor";
+
+    private final AudioTrack _audioTrack;
+    private final BlockingQueue<byte[]> _queue;
+
+    public AudioPlayer(AudioTrack audioTrack, BlockingQueue<byte[]> queue)
+    {
+        _audioTrack = audioTrack;
+        _queue = queue;
+    }
+
+    @Override
+    public void run()
+    {
+        Log.i(TAG, "Audio player thread started");
+
+        android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
+
+        _audioTrack.play();
+
+        try
+        {
+            while(Thread.currentThread().isInterrupted() == false)
+            {
+                byte [] data = _queue.take();
+                int written = _audioTrack.write(data, 0, data.length);
+
+                if(written != data.length)
+                {
+                    Log.i(TAG, "Did not write bytes: " + (data.length - written));
+                }
+            }
+        }
+        catch (InterruptedException e)
+        {
+
+        }
+
+        Log.i(TAG, "Audio player thread stopping");
+        _audioTrack.stop();
+    }
+}