Use a packet buffer pool to reduce memory pressure

src/com/limelight/nvstream/NvVideoStream.java

@@ -16,6 +16,7 @@ import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 
 import com.limelight.nvstream.av.AvBufferDescriptor;
+import com.limelight.nvstream.av.AvBufferPool;
 import com.limelight.nvstream.av.AvDecodeUnit;
 import com.limelight.nvstream.av.AvPacket;
 import com.limelight.nvstream.av.AvParser;
@@ -35,10 +36,11 @@ public class NvVideoStream {
 	public static final int RTCP_PORT = 47999;
 	public static final int FIRST_FRAME_PORT = 47996;
 	
-	private static final int FRAME_RATE = 60;
 	private ByteBuffer[] videoDecoderInputBuffers = null;
 	private MediaCodec videoDecoder;
 	
+	private AvBufferPool pool = new AvBufferPool(1500);
+	
 	private AvParser parser = new AvParser();
 	
 	private InputStream getFirstFrame(String host) throws UnknownHostException, IOException
@@ -151,6 +153,9 @@ public class NvVideoStream {
 										for (AvBufferDescriptor desc : du.getBufferList())
 										{
 											buf.put(desc.data, desc.offset, desc.length);
+											
+											// Release the buffer back to the buffer pool
+											pool.free(desc.data);
 										}
 									
 										videoDecoder.queueInputBuffer(inputIndex,
@@ -175,13 +180,11 @@ public class NvVideoStream {
 
 					@Override
 					public void run() {
-						byte[] buffer = new byte[1500];
+						DatagramPacket packet = new DatagramPacket(pool.allocate(), 1500);
 						AvBufferDescriptor desc = new AvBufferDescriptor(null, 0, 0);
 						
 						for (;;)
 						{	
-							DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
-							
 							try {
 								rtp.receive(packet);
 							} catch (IOException e) {
@@ -198,12 +201,13 @@ public class NvVideoStream {
 							desc.offset += 12;
 							desc.length -= 12;
 							
-							// Give the data to the AV parser
+							// !!! We no longer own the data buffer at this point !!!
 							parser.addInputData(new AvPacket(desc));
 							
+							// Get a new buffer from the buffer pool
+							packet.setData(pool.allocate(), 0, 1500);
 						}
 					}
-					
 				}).start();
 				
 				for (;;)
@@ -232,11 +236,4 @@ public class NvVideoStream {
 			}
 		}).start();
 	}
-	
-    /**
-     * Generates the presentation time for frame N, in microseconds.
-     */
-    private static long computePresentationTime(int frameIndex) {
-        return 132 + frameIndex * 1000000 / FRAME_RATE;
-    }
 }

src/com/limelight/nvstream/av/AvBufferPool.java

@@ -0,0 +1,30 @@
+package com.limelight.nvstream.av;
+
+import java.util.LinkedList;
+
+public class AvBufferPool {
+	private LinkedList<byte[]> bufferList = new LinkedList<byte[]>();
+	private int bufferSize;
+	
+	public AvBufferPool(int size)
+	{
+		this.bufferSize = size;
+	}
+	
+	public synchronized byte[] allocate()
+	{
+		if (bufferList.isEmpty())
+		{
+			return new byte[bufferSize];
+		}
+		else
+		{
+			return bufferList.removeFirst();
+		}
+	}
+	
+	public synchronized void free(byte[] buffer)
+	{
+		bufferList.addFirst(buffer);
+	}
+}

src/com/limelight/nvstream/av/AvPacket.java

@@ -5,14 +5,11 @@ public class AvPacket {
 	
 	public AvPacket(AvBufferDescriptor rtpPayload)
 	{
-		byte[] data = new byte[rtpPayload.length];
+		buffer = new AvBufferDescriptor(rtpPayload.data, rtpPayload.offset, rtpPayload.length);
-		System.arraycopy(rtpPayload.data, rtpPayload.offset, data, 0, rtpPayload.length);
-		buffer = new AvBufferDescriptor(data, 0, data.length);
 	}
 	
-	public AvBufferDescriptor getPayload()
+	public AvBufferDescriptor getNewPayloadDescriptor()
 	{
-		int payloadOffset = buffer.offset+56;
+		return new AvBufferDescriptor(buffer.data, buffer.offset+56, buffer.length-56);
-		return new AvBufferDescriptor(buffer.data, payloadOffset, buffer.length-payloadOffset);
 	}
 }

src/com/limelight/nvstream/av/AvParser.java

@@ -1,7 +1,6 @@
 package com.limelight.nvstream.av;
 
 import java.util.LinkedList;
-import java.util.List;
 import java.util.concurrent.LinkedBlockingQueue;
 
 public class AvParser {
@@ -29,8 +28,9 @@ public class AvParser {
 	
 	public void addInputData(AvPacket packet)
 	{		
-		AvBufferDescriptor payload = packet.getPayload();
+		// This payload buffer descriptor belongs to us
-		AvBufferDescriptor location = new AvBufferDescriptor(payload.data, payload.offset, payload.length);
+		AvBufferDescriptor location = packet.getNewPayloadDescriptor();
+		int payloadLength = location.length;
 		
 		while (location.length != 0)
 		{
@@ -47,9 +47,9 @@ public class AvParser {
 				nalDataChain = new LinkedList<AvBufferDescriptor>();
 				nalDataLength = 0;
 				
-				// Skip the start sequence and the type byte
+				// Skip the start sequence
-				location.length -= 5;
+				location.length -= 4;
-				location.offset += 5;
+				location.offset += 4;
 			}
 			
 			// If there's a NAL assembly in progress, add the current data
@@ -58,7 +58,7 @@ public class AvParser {
 				// FIXME: This is a hack to make parsing full packets
 				// take less time. We assume if they don't start with
 				// a NAL start sequence, they're full of NAL data
-				if (payload.length == 968)
+				if (payloadLength == 968)
 				{
 					location.offset += location.length;
 					location.length = 0;