Started coding the image transfer protocol.

src/ve/ucv/ciens/ccg/nxtcam/camera/CameraImageMonitor.java

@@ -16,6 +16,7 @@
 package ve.ucv.ciens.ccg.nxtcam.camera;
 
 import ve.ucv.ciens.ccg.nxtcam.utils.Logger;
+import android.graphics.Rect;
 
 public class CameraImageMonitor{
 	private final String TAG = "CAM_MONITOR";
@@ -23,13 +24,15 @@ public class CameraImageMonitor{
 
 	private Object imageMonitor;
 	private byte[] image;
-	private boolean imgProduced;
+	private boolean imageProduced;
-	private boolean imgConsumed;
+	private boolean imageConsumed;
+	private Rect imageSize;
 
 	private CameraImageMonitor(){
-		imgProduced = false;
+		imageProduced = false;
-		imgConsumed = true;
+		imageConsumed = true;
 		imageMonitor = new Object();
+		imageSize = null;
 	}
 
 	private static class SingletonHolder{
@@ -40,13 +43,21 @@ public class CameraImageMonitor{
 		return SingletonHolder.INSTANCE;
 	}
 
+	public void setImageParameters(int width, int height){
+		imageSize = new Rect(0, 0, width, height);
+	}
+	
+	public Rect getImageParameters(){
+		return imageSize;
+	}
+	
 	public void setImageData(byte[] image){
-		if(imgConsumed){
+		if(imageConsumed){
 			Logger.log_d(TAG, CLASS_NAME + ".setImageData() :: Copying new image.");
 			synchronized(this.imageMonitor){
 				this.image = image;
-				imgProduced = true;
+				imageProduced = true;
-				imgConsumed = false;
+				imageConsumed = false;
 				this.imageMonitor.notifyAll();
 			}
 			Logger.log_d(TAG, CLASS_NAME + ".setImageData() :: Data copy finished.");
@@ -59,20 +70,20 @@ public class CameraImageMonitor{
 		byte[] returnImg;
 		Logger.log_d(TAG, CLASS_NAME + ".getImageData() :: Entry point.");
 		synchronized(imageMonitor){
-			while(!imgProduced){
+			while(!imageProduced){
 				Logger.log_d(TAG, CLASS_NAME + ".getImageData() :: Waiting for new image.");
 				try{ imageMonitor.wait(); }catch(InterruptedException ie){ }
 			}
 			Logger.log_d(TAG, CLASS_NAME + ".getImageData() :: Retrieving new image.");
 			returnImg = image;
-			imgProduced = false;
+			imageProduced = false;
-			imgConsumed = true;
+			imageConsumed = true;
 		}
 		Logger.log_d(TAG, CLASS_NAME + ".getImageData() :: New image retrieved.");
 		return returnImg;
 	}
 
 	public synchronized boolean hasChanged(){
-		return imgConsumed;
+		return imageConsumed;
 	}
 }

src/ve/ucv/ciens/ccg/nxtcam/camera/CameraPreview.java

@@ -138,6 +138,9 @@ public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback
 
 	@Override
 	public void onPreviewFrame(byte[] data, Camera camera){
+		Size previewSize = camera.getParameters().getPreviewSize();
+		if(imgMonitor.hasChanged())
+			imgMonitor.setImageParameters(previewSize.width, previewSize.height);
 		Logger.log_d(TAG, CLASS_NAME + ".onPreviewFrame() :: Preview received");
 		Logger.log_d(TAG, CLASS_NAME + ".onPreviewFrame() :: Frame has" + (imgMonitor.hasChanged() ? "" : " not") + " been consumed.");
 		imgMonitor.setImageData(data);

src/ve/ucv/ciens/ccg/nxtcam/network/ImageTransferThread.java

@@ -15,30 +15,36 @@
  */
 package ve.ucv.ciens.ccg.nxtcam.network;
 
-import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
-import java.io.BufferedWriter;
 import java.io.IOException;
-import java.io.InputStreamReader;
+import java.io.ObjectInputStream;
-import java.io.OutputStreamWriter;
+import java.io.ObjectOutputStream;
 import java.net.InetAddress;
 import java.net.Socket;
 
 import ve.ucv.ciens.ccg.nxtcam.camera.CameraImageMonitor;
+import ve.ucv.ciens.ccg.nxtcam.network.protocols.ImageDataMessage;
+import ve.ucv.ciens.ccg.nxtcam.network.protocols.ImageTransferProtocol;
+import ve.ucv.ciens.ccg.nxtcam.network.protocols.ImageTransferProtocolMessage;
 import ve.ucv.ciens.ccg.nxtcam.utils.Logger;
 import ve.ucv.ciens.ccg.nxtcam.utils.ProjectConstants;
+import android.graphics.ImageFormat;
+import android.graphics.Rect;
+import android.graphics.YuvImage;
 
 public class ImageTransferThread extends Thread{
 	private final String TAG = "IM_THREAD";
 	private final String CLASS_NAME = ImageTransferThread.class.getSimpleName();
 
+	private enum thread_state_t {WAIT_FOR_ACK, WAIT_FOR_READY, CAN_SEND, END_STREAM};
+
 	private boolean pause, done;
 	private Object threadPauseMonitor;
 	private CameraImageMonitor camMonitor;
 	private Socket socket;
-	private BufferedWriter writer;
+	private ObjectOutputStream writer;
-	private BufferedReader reader;
+	private ObjectInputStream reader;	private String serverIp;
-	private byte[] image;
+	private thread_state_t threadState;
-	private String serverIp;
 
 	public ImageTransferThread(String serverIp){
 		this.serverIp = serverIp;
@@ -49,17 +55,94 @@ public class ImageTransferThread extends Thread{
 		writer = null;
 		reader = null;
 		camMonitor = CameraImageMonitor.getInstance();
+		threadState = thread_state_t.WAIT_FOR_READY;
 	}
 
 	public void run(){
+		byte[] image;
+		Object auxiliary;
+		ImageTransferProtocolMessage simpleMessage;
+		ImageDataMessage imageMessage;
+
 		connectToServer();
+
 		if(socket.isConnected()){
 			Logger.log_e(TAG, CLASS_NAME + ".run() :: Not connected to a server. Finishing thread.");
 		}else{
 			while(!done){
-				checkPause();
+				// checkPause();
-				image = camMonitor.getImageData();
+				switch(threadState){
-				// TODO: implement image transfer protocol.
+				case WAIT_FOR_READY:
+					auxiliary = readMessage();
+
+					if(!validateImageTransferProtocolMessage(auxiliary)){
+						// If the message received is not valid then send an UNRECOGNIZED message to the server.
+						Logger.log_d(TAG, CLASS_NAME + ".run() :: Received an unrecognized protocol message. State WAIT_FOR_READY.");
+						Logger.log_d(TAG, CLASS_NAME + ".run() :: Sending UNRECOGNIZED message to server.");
+						sendUnrecognizedMessage();
+
+					}else{
+						// Else if the passed the validity check then proceed to the next protocol state.
+						simpleMessage = (ImageTransferProtocolMessage)auxiliary;
+						if(simpleMessage.message == ImageTransferProtocol.FLOW_CONTROL_CONTINUE)
+							threadState = thread_state_t.CAN_SEND;
+						else if(simpleMessage.message == ImageTransferProtocol.STREAM_CONTROL_END)
+							threadState = thread_state_t.END_STREAM;
+					}
+					break;
+
+				case WAIT_FOR_ACK:
+					auxiliary = readMessage();
+
+					if(!validateImageTransferProtocolMessage(auxiliary)){
+						// If the message received is not valid then send an UNRECOGNIZED message to the server.
+						Logger.log_d(TAG, CLASS_NAME + ".run() :: Received an unrecognized protocol message. State WAIT_FOR_ACK.");
+						Logger.log_d(TAG, CLASS_NAME + ".run() :: Sending UNRECOGNIZED message to server.");
+						sendUnrecognizedMessage();
+
+					}else{
+						// Else if the passed the validity check then proceed to the next protocol state.
+						simpleMessage = (ImageTransferProtocolMessage)auxiliary;
+						if(simpleMessage.message == ImageTransferProtocol.ACK_SEND_NEXT)
+							threadState = thread_state_t.CAN_SEND;
+						else if(simpleMessage.message == ImageTransferProtocol.ACK_WAIT)
+							threadState = thread_state_t.WAIT_FOR_READY;
+						else if(simpleMessage.message == ImageTransferProtocol.STREAM_CONTROL_END)
+							threadState = thread_state_t.END_STREAM;
+					}
+					break;
+
+				case CAN_SEND:
+					final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+
+					// Get the image and it's parameters from the monitor.
+					Rect imageSize = camMonitor.getImageParameters();
+					image = camMonitor.getImageData();
+
+					// Compress the image as Jpeg.
+					YuvImage yuvImage = new YuvImage(image, ImageFormat.NV21, imageSize.width(), imageSize.height(), null);
+					yuvImage.compressToJpeg(imageSize, 90, outputStream);
+
+					// Prepare the message for sending.
+					imageMessage = new ImageDataMessage();
+					imageMessage.imageWidth = imageSize.width();
+					imageMessage.imageHeight = imageSize.height();
+					imageMessage.data = outputStream.toByteArray();
+
+					// Send the message.
+					try{
+						writer.writeObject(imageMessage);
+					}catch(IOException io){
+						Logger.log_e(TAG, CLASS_NAME + ".run() :: Error sending image to the server: " + io.getMessage());
+					}
+					break;
+
+				case END_STREAM:
+					// Simply disconnect from the server.
+					disconnect();
+					break;
+				}
+
 			}
 		}
 	}
@@ -68,8 +151,8 @@ public class ImageTransferThread extends Thread{
 		try{
 			Logger.log_i(TAG, CLASS_NAME + ".connectToServer() :: Connecting to the server at " + serverIp);
 			socket = new Socket(InetAddress.getByName(serverIp), ProjectConstants.SERVER_TCP_PORT_1);
-			writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
+			writer = new ObjectOutputStream(socket.getOutputStream());
-			reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+			reader = new ObjectInputStream(socket.getInputStream());
 			Logger.log_i(TAG, CLASS_NAME + ".connectToServer() :: Connection successful.");
 		}catch(IOException io){
 			Logger.log_e(TAG, CLASS_NAME + ".connectToServer() :: Connection failed with message: " + io.getMessage());
@@ -100,6 +183,45 @@ public class ImageTransferThread extends Thread{
 		}
 	}
 
+	private Object readMessage(){
+		Object auxiliary;
+
+		// Read a message from the server stream.
+		try{
+			auxiliary = reader.readObject();
+
+		}catch(IOException io){
+			Logger.log_e(TAG, CLASS_NAME + ".run() :: IOException when reading in WAIT_FOR_READY state.");
+			auxiliary = null;
+			return null;
+		}catch(ClassNotFoundException cn){
+			Logger.log_e(TAG, CLASS_NAME + ".run() :: ClassNotFoundException when reading in WAIT_FOR_READY state.");
+			auxiliary = null;
+			return null;
+		}
+
+		return auxiliary;
+	}
+
+	private boolean validateImageTransferProtocolMessage(Object message){
+		if(message != null && message instanceof ImageTransferProtocolMessage)
+			return true;
+		else
+			return false;
+	}
+
+	private void sendUnrecognizedMessage(){
+		ImageTransferProtocolMessage message = new ImageTransferProtocolMessage();
+		message.message = ImageTransferProtocol.UNRECOGNIZED;
+
+		try{
+			writer.writeObject(message);
+		}catch(IOException io){
+			Logger.log_e(TAG, CLASS_NAME + ".run() :: IOException when writing UNRECOGNIZED in WAIT_FOR_READY state.");
+		}
+		Logger.log_d(TAG, CLASS_NAME + ".run() :: UNRECOGNIZED message sent.");
+	}
+
 	public synchronized void pauseThread(){
 		pause = true;
 		Logger.log_d(TAG, CLASS_NAME + ".pauseThread() :: Pausing thread.");

src/ve/ucv/ciens/ccg/nxtcam/network/protocols/ImageDataMessage.java

@@ -0,0 +1,18 @@
+package ve.ucv.ciens.ccg.nxtcam.network.protocols;
+
+import java.io.Serializable;
+
+public final class ImageDataMessage extends ProtocolMessage implements Serializable{
+	private static final long serialVersionUID = 9989L;
+	public static final int magicNumber = 0x10;
+
+	public int imageWidth;
+	public int imageHeight;
+	public byte[] data;
+
+	public ImageDataMessage(){
+		imageWidth = -1;
+		imageHeight = -1;
+		data = null;
+	}
+}

src/ve/ucv/ciens/ccg/nxtcam/network/protocols/ImageTransferProtocol.java

@@ -15,17 +15,31 @@
  */
 package ve.ucv.ciens.ccg.nxtcam.network.protocols;
 
-public abstract class ImageTransferProtocol{
+public final class ImageTransferProtocol{
-	public static enum ProtocolState{
+	public static final byte STREAM_CONTROL_END = 0x10;
-		SALUTE, IMG_FOLLOWS, SEND_DATA, PAUSED, WAITING, GOODBYE
+	public static final byte ACK_SEND_NEXT = 0x20;
+	public static final byte ACK_WAIT = 0x30;
+	public static final byte FLOW_CONTROL_WAIT = 0x40;
+	public static final byte FLOW_CONTROL_CONTINUE = 0x50;
+	public static final byte IMAGE_DATA = 0x60;
+	public static final byte UNRECOGNIZED = (byte)0xFF;
+
+	public static boolean checkValidityOfMessage(byte message){
+		boolean validity;
+
+		switch(message){
+		case STREAM_CONTROL_END:
+		case ACK_SEND_NEXT:
+		case ACK_WAIT:
+		case FLOW_CONTROL_WAIT:
+		case FLOW_CONTROL_CONTINUE:
+		case IMAGE_DATA:
+		case UNRECOGNIZED:
+			validity = true;
+		default:
+			validity = false;
+		}
+
+		return validity;
 	}
-	
-	public static final byte MSG_HELLO = 			(byte)0x89;
-	public static final byte MSG_GOODBYE = 		(byte)0x90;
-	public static final byte MSG_IMG_DATA = 		(byte)0x42;
-	public static final byte CMD_IMG_FOLLOWS = 	(byte)0x10;
-	public static final byte CMD_PAUSE = 			(byte)0x15;
-	public static final byte CMD_IMG_WAIT = 		(byte)0x20;
-	public static final byte ACK_SEND_IMG = 		(byte)0x40;
-	public static final byte ACK_IMG_RCVD = 		(byte)0x50;
 }

src/ve/ucv/ciens/ccg/nxtcam/network/protocols/ImageTransferProtocolMessage.java

@@ -0,0 +1,14 @@
+package ve.ucv.ciens.ccg.nxtcam.network.protocols;
+
+import java.io.Serializable;
+
+public final class ImageTransferProtocolMessage extends ProtocolMessage implements Serializable{
+	private static final long serialVersionUID = 8898L;
+	public static final int magicNumber = 0x20;
+
+	public byte message;
+
+	public ImageTransferProtocolMessage(){
+		message = -1;
+	}
+}

src/ve/ucv/ciens/ccg/nxtcam/network/protocols/ProtocolMessage.java

@@ -0,0 +1,8 @@
+package ve.ucv.ciens.ccg.nxtcam.network.protocols;
+
+import java.io.Serializable;
+
+@SuppressWarnings("serial")
+public abstract class ProtocolMessage implements Serializable {
+	public static int magicNumber = 0x00;
+}