src/jlibrtp/RTPSession.java
changeset 823 2036ebfaccda
child 826 8649e502be0e
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jlibrtp/RTPSession.java	Fri Nov 20 19:29:42 2009 +0100
@@ -0,0 +1,1301 @@
+/**
+ * Java RTP Library (jlibrtp)
+ * Copyright (C) 2006 Arne Kepp
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+package jlibrtp;
+
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.MulticastSocket;
+import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.Random;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
+import org.sipdroid.net.tools.DataFramePool;
+import org.sipdroid.net.tools.DatagramPool;
+import org.sipdroid.net.tools.PktBufNodePool;
+import org.sipdroid.net.tools.RtpPktPool;
+
+import android.util.Log;
+
+/**
+ * The RTPSession object is the core of jlibrtp.
+ * 
+ * One should be instantiated for every communication channel, i.e. if you send
+ * voice and video, you should create one for each.
+ * 
+ * The instance holds a participant database, as well as other information about
+ * the session. When the application registers with the session, the necessary
+ * threads for receiving and processing RTP packets are spawned.
+ * 
+ * RTP Packets are sent synchronously, all other operations are asynchronous.
+ * 
+ * @author Arne Kepp
+ */
+public class RTPSession {
+	/**
+	 * The debug level is final to avoid compilation of if-statements.</br> 0
+	 * provides no debugging information, 20 provides everything </br> Debug
+	 * output is written to System.out</br> Debug level for RTP related things.
+	 */
+	final static public int rtpDebugLevel = 1;
+	/**
+	 * The debug level is final to avoid compilation of if-statements.</br> 0
+	 * provides no debugging information, 20 provides everything </br> Debug
+	 * output is written to System.out</br> Debug level for RTCP related things.
+	 */
+	final static public int rtcpDebugLevel = 1;
+
+	/** RTP unicast socket */
+	protected DatagramSocket rtpSock = null;
+	/** RTP multicast socket */
+	protected MulticastSocket rtpMCSock = null;
+	/** RTP multicast group */
+	protected InetAddress mcGroup = null;
+
+	// Internal state
+	/** Whether this session is a multicast session or not */
+	protected boolean mcSession = false;
+	/** Current payload type, can be changed by application */
+	protected int payloadType = 0;
+	/** SSRC of this session */
+	protected long ssrc;
+	/** The last timestamp when we sent something */
+	protected long lastTimestamp = 0;
+	/** Current sequence number */
+	protected int seqNum = 0;
+	/** Number of packets sent by this session */
+	protected int sentPktCount = 0;
+	/** Number of octets sent by this session */
+	protected int sentOctetCount = 0;
+
+	/** The random seed */
+	protected Random random = null;
+
+	/** Session bandwidth in BYTES per second */
+	protected int bandwidth = 8000;
+
+	/** By default we do not return packets from strangers in unicast mode */
+	protected boolean naiveReception = false;
+
+	/** Should the library attempt frame reconstruction? */
+	protected boolean frameReconstruction = true;
+
+	/** Maximum number of packets used for reordering */
+	protected int pktBufBehavior = 3;
+
+	/** Participant database */
+	protected ParticipantDatabase partDb = new ParticipantDatabase(this);
+	/** First participant */
+	protected Participant firstPart;
+	/** Handle to application interface for RTP */
+	protected RTPAppIntf appIntf = null;
+	/** Handle to application interface for RTCP (optional) */
+	protected RTCPAppIntf rtcpAppIntf = null;
+	/** Handle to application interface for AVPF, RFC 4585 (optional) */
+	protected RTCPAVPFIntf rtcpAVPFIntf = null;
+	/** Handle to application interface for debugging */
+	protected DebugAppIntf debugAppIntf = null;
+
+	/** The RTCP session associated with this RTP Session */
+	protected RTCPSession rtcpSession = null;
+	/** The thread for receiving RTP packets */
+	protected RTPReceiverThread recvThrd = null;
+	/** The thread for invoking callbacks for RTP packets */
+	protected AppCallerThread appCallerThrd = null;
+
+	/** Lock to protect the packet buffers */
+	final protected Lock pktBufLock = new ReentrantLock();
+	/** Condition variable, to tell the */
+	final protected Condition pktBufDataReady = pktBufLock.newCondition();
+
+	/** Enough is enough, set to true when you want to quit. */
+	protected boolean endSession = false;
+	/** Only one registered application, please */
+	protected boolean registered = false;
+	/** We're busy resolving a SSRC conflict, please try again later */
+	protected boolean conflict = false;
+	/** Number of conflicts observed, exessive number suggests loop in network */
+	protected int conflictCount = 0;
+
+	/** SDES CNAME */
+	protected String cname = null;
+	/** SDES The participant's real name */
+	public String name = null;
+	/** SDES The participant's email */
+	public String email = null;
+	/** SDES The participant's phone number */
+	public String phone = null;
+	/** SDES The participant's location */
+	public String loc = null;
+	/** SDES The tool the participants is using */
+	public String tool = null;
+	/** SDES A note */
+	public String note = null;
+	/** SDES A priv string, loosely defined */
+	public String priv = null;
+
+	// RFC 4585 stuff. This should live on RTCPSession, but we need to have this
+	// infromation ready by the time the RTCP Session starts
+	// 0 = RFC 3550 , -1 = ACK , 1 = Immediate feedback, 2 = Early RTCP,
+	protected int rtcpMode = 0;
+	protected int fbEarlyThreshold = -1; // group size, immediate -> early
+	// transition point
+	protected int fbRegularThreshold = -1; // group size, early -> regular
+	// transition point
+	protected int minInterval = 5000; // minimum interval
+	protected int fbMaxDelay = 1000; // how long the information is useful
+	// RTCP bandwidth
+	protected int rtcpBandwidth = -1;
+
+	/**
+	 * Returns an instance of a <b>unicast</b> RTP session. Following this you
+	 * should adjust any settings and then register your application.
+	 * 
+	 * The sockets should have external ip addresses, else your CNAME
+	 * automatically generated CNAMe will be bad.
+	 * 
+	 * @param rtpSocket
+	 *            UDP socket to receive RTP communication on
+	 * @param rtcpSocket
+	 *            UDP socket to receive RTCP communication on, null if none.
+	 */
+	public RTPSession(DatagramSocket rtpSocket, DatagramSocket rtcpSocket) {
+		mcSession = false;
+		rtpSock = rtpSocket;
+		this.generateCNAME();
+		this.generateSsrc();
+		this.rtcpSession = new RTCPSession(this, rtcpSocket);
+		// The sockets are not always imediately available?
+		try {
+			Thread.sleep(1);
+		} catch (InterruptedException e) {
+			System.out.println("RTPSession sleep failed");
+		}
+	}
+
+	/**
+	 * Returns an instance of a <b>multicast</b> RTP session. Following this you
+	 * should register your application.
+	 * 
+	 * The sockets should have external ip addresses, else your CNAME
+	 * automatically generated CNAMe will be bad.
+	 * 
+	 * @param rtpSock
+	 *            a multicast socket to receive RTP communication on
+	 * @param rtcpSock
+	 *            a multicast socket to receive RTP communication on
+	 * @param multicastGroup
+	 *            the multicast group that we want to communicate with.
+	 */
+	public RTPSession(MulticastSocket rtpSock, MulticastSocket rtcpSock,
+			InetAddress multicastGroup) throws Exception {
+		mcSession = true;
+		rtpMCSock = rtpSock;
+		mcGroup = multicastGroup;
+		rtpMCSock.joinGroup(mcGroup);
+		rtcpSock.joinGroup(mcGroup);
+		this.generateCNAME();
+		this.generateSsrc();
+		this.rtcpSession = new RTCPSession(this, rtcpSock, mcGroup);
+
+		// The sockets are not always imediately available?
+		try {
+			Thread.sleep(1);
+		} catch (InterruptedException e) {
+			System.out.println("RTPSession sleep failed");
+		}
+	}
+
+	/**
+	 * Registers an application (RTPAppIntf) with the RTP session. The session
+	 * will call receiveData() on the supplied instance whenever data has been
+	 * received.
+	 * 
+	 * Following this you should set the payload type and add participants to
+	 * the session.
+	 * 
+	 * @param rtpApp
+	 *            an object that implements the RTPAppIntf-interface
+	 * @param rtcpApp
+	 *            an object that implements the RTCPAppIntf-interface (optional)
+	 * @return -1 if this RTPSession-instance already has an application
+	 *         registered.
+	 */
+	public int RTPSessionRegister(RTPAppIntf rtpApp, RTCPAppIntf rtcpApp,
+			DebugAppIntf debugApp) {
+		if (registered) {
+			System.out
+			.println("RTPSessionRegister(): Can\'t register another application!");
+			return -1;
+		} else {
+
+			registered = true;
+			generateSeqNum();
+			if (RTPSession.rtpDebugLevel > 0) {
+				System.out.println("-> RTPSessionRegister");
+			}
+			this.appIntf = rtpApp;
+			this.rtcpAppIntf = rtcpApp;
+			this.debugAppIntf = debugApp;
+
+			recvThrd = new RTPReceiverThread(this);
+			appCallerThrd = new AppCallerThread(this, rtpApp);
+			//recvThrd.start();
+			//appCallerThrd.start();
+			//rtcpSession.start();
+			return 0;
+		}
+	}
+
+	public AppCallerThread getAppCallerThrd() {
+		return appCallerThrd;
+	}
+
+	public RTPReceiverThread getRTPRecvThrd() {
+		return recvThrd;
+	}
+
+	/**
+	 * Send data to all participants registered as receivers, using the current
+	 * timeStamp, dynamic sequence number and the current payload type specified
+	 * for the session.
+	 * 
+	 * @param buf
+	 *            A buffer of bytes, less than 1496 bytes
+	 * @return null if there was a problem, {RTP Timestamp, Sequence number}
+	 *         otherwise
+	 */
+	public long[] sendData(byte[] buf) {
+		byte[][] tmp = { buf };
+		long[][] ret = this.sendData(tmp, null, null, -1, null);
+
+		if (ret != null)
+			return ret[0];
+
+		return null;
+	}
+
+	/**
+	 * Send data to all participants registered as receivers, using the
+	 * specified timeStamp, sequence number and the current payload type
+	 * specified for the session.
+	 * 
+	 * @param buf
+	 *            A buffer of bytes, less than 1496 bytes
+	 * @param rtpTimestamp
+	 *            the RTP timestamp to be used in the packet
+	 * @param seqNum
+	 *            the sequence number to be used in the packet
+	 * @return null if there was a problem, {RTP Timestamp, Sequence number}
+	 *         otherwise
+	 */
+	public long[] sendData(byte[] buf, long rtpTimestamp, long seqNum) {
+		byte[][] tmp = { buf };
+		long[][] ret = this.sendData(tmp, null, null, -1, null);
+
+		if (ret != null)
+			return ret[0];
+
+		return null;
+	}
+
+	/**
+	 * Send data to all participants registered as receivers, using the current
+	 * timeStamp and payload type. The RTP timestamp will be the same for all
+	 * the packets.
+	 * 
+	 * @param buffers
+	 *            A buffer of bytes, should not bed padded and less than 1500
+	 *            bytes on most networks.
+	 * @param csrcArray
+	 *            an array with the SSRCs of contributing sources
+	 * @param markers
+	 *            An array indicating what packets should be marked. Rarely
+	 *            anything but the first one
+	 * @param rtpTimestamp
+	 *            The RTP timestamp to be applied to all packets
+	 * @param seqNumbers
+	 *            An array with the sequence number associated with each byte[]
+	 * @return null if there was a problem sending the packets, 2-dim array with
+	 *         {RTP Timestamp, Sequence number}
+	 */
+	public long[][] sendData(byte[][] buffers, long[] csrcArray,
+			boolean[] markers, long rtpTimestamp, long[] seqNumbers) {
+		if (RTPSession.rtpDebugLevel > 5) {
+			System.out.println("-> RTPSession.sendData(byte[])");
+		}
+
+		// Same RTP timestamp for all
+		if (rtpTimestamp < 0)
+			rtpTimestamp = System.currentTimeMillis();
+
+		// Return values
+		long[][] ret = new long[buffers.length][2];
+
+		for (int i = 0; i < buffers.length; i++) {
+			byte[] buf = buffers[i];
+
+			boolean marker = false;
+			if (markers != null)
+				marker = markers[i];
+
+			if (buf.length > 1500) {
+				System.out
+				.println("RTPSession.sendData() called with buffer exceeding 1500 bytes ("
+						+ buf.length + ")");
+			}
+
+			// Get the return values
+			ret[i][0] = rtpTimestamp;
+			if (seqNumbers == null) {
+				ret[i][1] = getNextSeqNum();
+			} else {
+				ret[i][1] = seqNumbers[i];
+			}
+			// Create a new RTP Packet
+			RtpPkt pkt = RtpPktPool.getInstance().borrowPkt();
+			pkt.initPacket(rtpTimestamp, this.ssrc, (int) ret[i][1],
+					this.payloadType, buf);
+
+			if (csrcArray != null)
+				pkt.setCsrcs(csrcArray);
+
+			pkt.setMarked(marker);
+
+			// Creates a raw packet
+			byte[] pktBytes = pkt.encode();
+
+			// System.out.println(Integer.toString(StaticProcs.bytesToUIntInt(pktBytes,
+			// 2)));
+
+			// Pre-flight check, are resolving an SSRC conflict?
+			if (this.conflict) {
+				System.out
+				.println("RTPSession.sendData() called while trying to resolve conflict.");
+				return null;
+			}
+
+			if (this.mcSession) {
+				DatagramPacket packet = null;
+
+				try {
+					packet = new DatagramPacket(pktBytes, pktBytes.length,
+							this.mcGroup, this.rtpMCSock.getPort());
+				} catch (Exception e) {
+					System.out
+					.println("RTPSession.sendData() packet creation failed.");
+					e.printStackTrace();
+					return null;
+				}
+
+				try {
+					rtpMCSock.send(packet);
+					// Debug
+					if (this.debugAppIntf != null) {
+						this.debugAppIntf.packetSent(1,
+								(InetSocketAddress) packet.getSocketAddress(),
+								new String("Sent multicast RTP packet of size "
+										+ packet.getLength()
+										+ " to "
+										+ packet.getSocketAddress().toString()
+										+ " via "
+										+ rtpMCSock.getLocalSocketAddress()
+										.toString()));
+					}
+				} catch (Exception e) {
+					System.out
+					.println("RTPSession.sendData() multicast failed.");
+					e.printStackTrace();
+					return null;
+				}
+
+			} else {
+				// Loop over recipients
+				Iterator<Participant> iter = partDb.getUnicastReceivers();
+				while (iter.hasNext()) {
+					InetSocketAddress receiver = iter.next().rtpAddress;
+					DatagramPacket packet = null;
+
+					if (RTPSession.rtpDebugLevel > 15) {
+						System.out.println("   Sending to "
+								+ receiver.toString());
+					}
+
+					try {
+						packet = new DatagramPacket(pktBytes, pktBytes.length,
+								receiver);
+					} catch (Exception e) {
+						System.out
+						.println("RTPSession.sendData() packet creation failed.");
+						e.printStackTrace();
+						return null;
+					}
+
+					// Actually send the packet
+					try {
+						rtpSock.send(packet);
+						// Debug
+						if (this.debugAppIntf != null) {
+							this.debugAppIntf
+							.packetSent(
+									0,
+									(InetSocketAddress) packet
+									.getSocketAddress(),
+									new String(
+											"Sent unicast RTP packet of size "
+											+ packet
+											.getLength()
+											+ " to "
+											+ packet
+											.getSocketAddress()
+											.toString()
+											+ " via "
+											+ rtpSock
+											.getLocalSocketAddress()
+											.toString()));
+						}
+					} catch (Exception e) {
+						System.out
+						.println("RTPSession.sendData() unicast failed.");
+						e.printStackTrace();
+						return null;
+					}
+				}
+			}
+
+			// Update our stats
+			this.sentPktCount++;
+			this.sentOctetCount++;
+
+			if (RTPSession.rtpDebugLevel > 5) {
+				System.out.println("<- RTPSession.sendData(byte[]) "
+						+ pkt.getSeqNumber());
+			}
+		}
+
+		return ret;
+	}
+
+	public void sendData(DatagramPacket packet, RtpPkt pkt) {
+		if (RTPSession.rtpDebugLevel > 5) {
+			System.out.println("-> RTPSession.sendData(byte[])");
+		}
+
+		pkt.setTimeStamp(System.currentTimeMillis());
+		pkt.setSsrc(ssrc);
+		pkt.setSeqNumber(getNextSeqNum());
+
+		// Creates a raw packet
+		pkt.writeHeader();
+
+		// Pre-flight check, are resolving an SSRC conflict?
+		if (this.conflict) {
+			System.out
+			.println("RTPSession.sendData() called while trying to resolve conflict.");
+			return;
+		}
+
+		if (this.mcSession) {
+			try {
+				packet.setPort(this.rtpMCSock.getPort());
+				packet.setAddress(this.mcGroup);
+			} catch (Exception e) {
+				System.out
+				.println("RTPSession.sendData() packet creation failed.");
+				e.printStackTrace();
+				return;
+			}
+			try {
+				rtpMCSock.send(packet);
+				// Debug
+				if (this.debugAppIntf != null) {
+					this.debugAppIntf.packetSent(1,
+							(InetSocketAddress) packet.getSocketAddress(),
+							new String("Sent multicast RTP packet of size "
+									+ packet.getLength()
+									+ " to "
+									+ packet.getSocketAddress().toString()
+									+ " via "
+									+ rtpMCSock.getLocalSocketAddress()
+									.toString()));
+				}
+			} catch (Exception e) {
+				System.out
+				.println("RTPSession.sendData() multicast failed.");
+				e.printStackTrace();
+				return;
+			}
+
+		} else {
+			try {
+				packet.setSocketAddress(firstPart.rtpAddress);
+			} catch (Exception e) {
+				System.out
+				.println("RTPSession.sendData() packet creation failed.");
+				e.printStackTrace();
+				return;
+			}
+
+			// Actually send the packet
+			try {
+				
+				rtpSock.send(packet);
+				Log.d("RTP", "packet");
+				// Debug
+				if (this.debugAppIntf != null) {
+					this.debugAppIntf
+					.packetSent(
+							0,
+							(InetSocketAddress) packet
+							.getSocketAddress(),
+							new String(
+									"Sent unicast RTP packet of size "
+									+ packet
+									.getLength()
+									+ " to "
+									+ packet
+									.getSocketAddress()
+									.toString()
+									+ " via "
+									+ rtpSock
+									.getLocalSocketAddress()
+									.toString()));
+				}
+			} catch (Exception e) {
+				System.out
+				.println("RTPSession.sendData() unicast failed.");
+				e.printStackTrace();
+				return;
+			}
+		}
+
+		// Update our stats
+		this.sentPktCount++;
+		this.sentOctetCount++;
+		if (RTPSession.rtpDebugLevel > 5) {
+			System.out.println("<- RTPSession.sendData(byte[]) "
+					+ pkt.getSeqNumber());
+		}
+	}
+
+	/**
+	 * Send RTCP App packet to receiver specified by ssrc
+	 * 
+	 * 
+	 * 
+	 * Return values: 0 okay -1 no RTCP session established -2 name is not
+	 * byte[4]; -3 data is not byte[x], where x = 4*y for syme y -4 type is not
+	 * a 5 bit unsigned integer
+	 * 
+	 * Note that a return value of 0 does not guarantee delivery. The
+	 * participant must also exist in the participant database, otherwise the
+	 * message will eventually be deleted.
+	 * 
+	 * @param ssrc
+	 *            of the participant you want to reach
+	 * @param type
+	 *            the RTCP App packet subtype, default 0
+	 * @param name
+	 *            the ASCII (in byte[4]) representation
+	 * @param data
+	 *            the data itself
+	 * @return 0 if okay, negative value otherwise (see above)
+	 */
+
+	public int sendRTCPAppPacket(long ssrc, int type, byte[] name, byte[] data) {
+		if (this.rtcpSession == null)
+			return -1;
+
+		if (name.length != 4)
+			return -2;
+
+		if (data.length % 4 != 0)
+			return -3;
+
+		if (type > 63 || type < 0)
+			return -4;
+
+		RtcpPktAPP pkt = new RtcpPktAPP(ssrc, type, name, data);
+		this.rtcpSession.addToAppQueue(ssrc, pkt);
+
+		return 0;
+	}
+
+	/**
+	 * Add a participant object to the participant database.
+	 * 
+	 * If packets have already been received from this user, we will try to
+	 * update the automatically inserted participant with the information
+	 * provided here.
+	 * 
+	 * @param p
+	 *            A participant.
+	 */
+	public int addParticipant(Participant p) {
+		// For now we make all participants added this way persistent
+		firstPart = p;
+		p.unexpected = false;
+		return this.partDb.addParticipant(0, p);
+	}
+
+	/**
+	 * Remove a participant from the database. All buffered packets will be
+	 * destroyed.
+	 * 
+	 * @param p
+	 *            A participant.
+	 */
+	public void removeParticipant(Participant p) {
+		partDb.removeParticipant(p);
+	}
+
+	public Iterator<Participant> getUnicastReceivers() {
+		return partDb.getUnicastReceivers();
+	}
+
+	public Enumeration<Participant> getParticipants() {
+		return partDb.getParticipants();
+	}
+
+	/**
+	 * End the RTP Session. This will halt all threads and send bye-messages to
+	 * other participants.
+	 * 
+	 * RTCP related threads may require several seconds to wake up and
+	 * terminate.
+	 */
+	public void endSession() {
+		this.endSession = true;
+
+		// No more RTP packets, please
+		if (this.mcSession) {
+			this.rtpMCSock.close();
+		} else {
+			this.rtpSock.close();
+		}
+
+		// Signal the thread that pushes data to application
+		this.pktBufLock.lock();
+		try {
+			this.pktBufDataReady.signalAll();
+		} finally {
+			this.pktBufLock.unlock();
+		}
+		// Interrupt what may be sleeping
+		//this.rtcpSession.senderThrd.interrupt();
+
+		// Give things a chance to cool down.
+		try {
+			Thread.sleep(50);
+		} catch (Exception e) {
+		}
+		;
+
+		this.appCallerThrd.interrupt();
+
+		// Give things a chance to cool down.
+		try {
+			Thread.sleep(50);
+		} catch (Exception e) {
+		}
+		;
+
+		if (this.rtcpSession != null) {
+			// No more RTP packets, please
+			if (this.mcSession) {
+				this.rtcpSession.rtcpMCSock.close();
+			} else {
+				this.rtcpSession.rtcpSock.close();
+			}
+		}
+		DatagramPool.removeInstance();
+		PktBufNodePool.removeInstance();
+		DataFramePool.removeInstance();
+		RtpPktPool.removeInstance();
+	}
+
+	/**
+	 * Check whether this session is ending.
+	 * 
+	 * @return true if session and associated threads are terminating.
+	 */
+	boolean isEnding() {
+		return this.endSession;
+	}
+
+	/**
+	 * Overrides CNAME, used for outgoing RTCP packets.
+	 * 
+	 * @param cname
+	 *            a string, e.g. username@hostname. Must be unique for session.
+	 */
+	public void CNAME(String cname) {
+		this.cname = cname;
+	}
+
+	/**
+	 * Get the current CNAME, used for outgoing SDES packets
+	 */
+	public String CNAME() {
+		return this.cname;
+	}
+
+	public long getSsrc() {
+		return this.ssrc;
+	}
+
+	private void generateCNAME() {
+		String hostname;
+
+		if (this.mcSession) {
+			hostname = this.rtpMCSock.getLocalAddress().getCanonicalHostName();
+		} else {
+			hostname = this.rtpSock.getLocalAddress().getCanonicalHostName();
+		}
+
+		// if(hostname.equals("0.0.0.0") && System.getenv("HOSTNAME") != null) {
+		// hostname = System.getenv("HOSTNAME");
+		// }
+
+		cname = System.getProperty("user.name") + "@" + hostname;
+	}
+
+	/**
+	 * Change the RTP socket of the session. Peers must be notified through SIP
+	 * or other signalling protocol. Only valid if this is a unicast session to
+	 * begin with.
+	 * 
+	 * @param newSock
+	 *            integer for new port number, check it is free first.
+	 */
+	public int updateRTPSock(DatagramSocket newSock) {
+		if (!mcSession) {
+			rtpSock = newSock;
+			return 0;
+		} else {
+			System.out.println("Can't switch from multicast to unicast.");
+			return -1;
+		}
+	}
+
+	/**
+	 * Change the RTCP socket of the session. Peers must be notified through SIP
+	 * or other signalling protocol. Only valid if this is a unicast session to
+	 * begin with.
+	 * 
+	 * @param newSock
+	 *            the new unicast socket for RTP communication.
+	 */
+	public int updateRTCPSock(DatagramSocket newSock) {
+		if (!mcSession) {
+			this.rtcpSession.rtcpSock = newSock;
+			return 0;
+		} else {
+			System.out.println("Can't switch from multicast to unicast.");
+			return -1;
+		}
+	}
+
+	/**
+	 * Change the RTP multicast socket of the session. Peers must be notified
+	 * through SIP or other signalling protocol. Only valid if this is a
+	 * multicast session to begin with.
+	 * 
+	 * @param newSock
+	 *            the new multicast socket for RTP communication.
+	 */
+	public int updateRTPSock(MulticastSocket newSock) {
+		if (mcSession) {
+			this.rtpMCSock = newSock;
+			return 0;
+		} else {
+			System.out.println("Can't switch from unicast to multicast.");
+			return -1;
+		}
+	}
+
+	/**
+	 * Change the RTCP multicast socket of the session. Peers must be notified
+	 * through SIP or other signalling protocol. Only valid if this is a
+	 * multicast session to begin with.
+	 * 
+	 * @param newSock
+	 *            the new multicast socket for RTCP communication.
+	 */
+	public int updateRTCPSock(MulticastSocket newSock) {
+		if (mcSession) {
+			this.rtcpSession.rtcpMCSock = newSock;
+			return 0;
+		} else {
+			System.out.println("Can't switch from unicast to multicast.");
+			return -1;
+		}
+	}
+
+	/**
+	 * Update the payload type used for the session. It is represented as a 7
+	 * bit integer, whose meaning must be negotiated elsewhere (see IETF RFCs <a
+	 * href="http://www.ietf.org/rfc/rfc3550.txt">3550</a> and <a
+	 * href="http://www.ietf.org/rfc/rfc3550.txt">3551</a>)
+	 * 
+	 * @param payloadT
+	 *            an integer representing the payload type of any subsequent
+	 *            packets that are sent.
+	 */
+	public int payloadType(int payloadT) {
+		if (payloadT > 128 || payloadT < 0) {
+			return -1;
+		} else {
+			this.payloadType = payloadT;
+			return this.payloadType;
+		}
+	}
+
+	/**
+	 * Get the payload type that is currently used for outgoing RTP packets.
+	 * 
+	 * @return payload type as integer
+	 */
+	public int payloadType() {
+		return this.payloadType;
+	}
+
+	/**
+	 * Should packets from unknown participants be returned to the application?
+	 * This can be dangerous.
+	 * 
+	 * @param doAccept
+	 *            packets from participants not added by the application.
+	 */
+	public void naivePktReception(boolean doAccept) {
+		naiveReception = doAccept;
+	}
+
+	/**
+	 * Are packets from unknown participants returned to the application?
+	 * 
+	 * @return whether we accept packets from participants not added by the
+	 *         application.
+	 */
+	public boolean naivePktReception() {
+		return naiveReception;
+	}
+
+	/**
+	 * Set the number of RTP packets that should be buffered when a packet is
+	 * missing or received out of order. Setting this number high increases the
+	 * chance of correctly reordering packets, but increases latency when a
+	 * packet is dropped by the network.
+	 * 
+	 * Packets that arrive in order are not affected, they are passed straight
+	 * to the application.
+	 * 
+	 * The maximum delay is numberofPackets * packet rate , where the packet
+	 * rate depends on the codec and profile used by the sender.
+	 * 
+	 * Valid values: >0 - The maximum number of packets (based on RTP Timestamp)
+	 * that may accumulate 0 - All valid packets received in order will be given
+	 * to the application -1 - All valid packets will be given to the
+	 * application
+	 * 
+	 * @param behavior
+	 *            the be
+	 * @return the behavior set, unchanged in the case of a erroneous value
+	 */
+	public int packetBufferBehavior(int behavior) {
+		if (behavior > -2) {
+			this.pktBufBehavior = behavior;
+			// Signal the thread that pushes data to application
+			this.pktBufLock.lock();
+			try {
+				this.pktBufDataReady.signalAll();
+			} finally {
+				this.pktBufLock.unlock();
+			}
+			return this.pktBufBehavior;
+		} else {
+			return this.pktBufBehavior;
+		}
+	}
+
+	/**
+	 * The number of RTP packets that should be buffered when a packet is
+	 * missing or received out of order. A high number increases the chance of
+	 * correctly reordering packets, but increases latency when a packet is
+	 * dropped by the network.
+	 * 
+	 * A negative value disables the buffering, out of order packets will simply
+	 * be dropped.
+	 * 
+	 * @return the maximum number of packets that can accumulate before the
+	 *         first is returned
+	 */
+	public int packetBufferBehavior() {
+		return this.pktBufBehavior;
+	}
+
+	/**
+	 * Set whether the stack should operate in RFC 4585 mode.
+	 * 
+	 * This will automatically call adjustPacketBufferBehavior(-1), i.e. disable
+	 * all RTP packet buffering in jlibrtp, and disable frame reconstruction
+	 * 
+	 * @param rtcpAVPFIntf
+	 *            the in
+	 */
+	public int registerAVPFIntf(RTCPAVPFIntf rtcpAVPFIntf, int maxDelay,
+			int earlyThreshold, int regularThreshold) {
+		if (this.rtcpSession != null) {
+			this.packetBufferBehavior(-1);
+			this.frameReconstruction = false;
+			this.rtcpAVPFIntf = rtcpAVPFIntf;
+			this.fbEarlyThreshold = earlyThreshold;
+			this.fbRegularThreshold = regularThreshold;
+			return 0;
+		} else {
+			return -1;
+		}
+	}
+
+	/**
+	 * Unregisters the RTCP AVPF interface, thereby going from RFC 4585 mode to
+	 * RFC 3550
+	 * 
+	 * You still have to adjust packetBufferBehavior() and frameReconstruction.
+	 * 
+	 */
+	public void unregisterAVPFIntf() {
+		this.fbEarlyThreshold = -1;
+		this.fbRegularThreshold = -1;
+		this.rtcpAVPFIntf = null;
+	}
+
+	/**
+	 * Enable / disable frame reconstruction in the packet buffers. This is only
+	 * relevant if getPacketBufferBehavior > 0;
+	 * 
+	 * Default is true.
+	 */
+	public void frameReconstruction(boolean toggle) {
+		this.frameReconstruction = toggle;
+	}
+
+	/**
+	 * Whether the packet buffer will attempt to reconstruct packet
+	 * automatically.
+	 * 
+	 * @return the status
+	 */
+	public boolean frameReconstruction() {
+		return this.frameReconstruction;
+	}
+
+	/**
+	 * The bandwidth currently allocated to the session, in bytes per second.
+	 * The default is 8000.
+	 * 
+	 * This value is not enforced and currently only used to calculate the RTCP
+	 * interval to ensure the control messages do not exceed 5% of the total
+	 * bandwidth described here.
+	 * 
+	 * Since the actual value may change a conservative estimate should be used
+	 * to avoid RTCP flooding.
+	 * 
+	 * see rtcpBandwidth(void)
+	 * 
+	 * @return current bandwidth setting
+	 */
+	public int sessionBandwidth() {
+		return this.bandwidth;
+	}
+
+	/**
+	 * Set the bandwidth of the session.
+	 * 
+	 * See sessionBandwidth(void) for details.
+	 * 
+	 * @param bandwidth
+	 *            the new value requested, in bytes per second
+	 * @return the actual value set
+	 */
+	public int sessionBandwidth(int bandwidth) {
+		if (bandwidth < 1) {
+			this.bandwidth = 8000;
+		} else {
+			this.bandwidth = bandwidth;
+		}
+		return this.bandwidth;
+	}
+
+	/**
+	 * RFC 3550 dictates that 5% of the total bandwidth, as set by
+	 * sessionBandwidth, should be dedicated to RTCP traffic. This
+	 * 
+	 * This should normally not be done, but is permissible in conjunction with
+	 * feedback (RFC 4585) and possibly other profiles.
+	 * 
+	 * Also see sessionBandwidth(void)
+	 * 
+	 * @return current RTCP bandwidth setting, -1 means not in use
+	 */
+	public int rtcpBandwidth() {
+		return this.rtcpBandwidth;
+	}
+
+	/**
+	 * Set the RTCP bandwidth, see rtcpBandwidth(void) for details.
+	 * 
+	 * This function must be
+	 * 
+	 * @param bandwidth
+	 *            the new value requested, in bytes per second or -1 to disable
+	 * @return the actual value set
+	 */
+	public int rtcpBandwidth(int bandwidth) {
+		if (bandwidth < -1) {
+			this.rtcpBandwidth = -1;
+		} else {
+			this.rtcpBandwidth = bandwidth;
+		}
+		return this.rtcpBandwidth;
+	}
+
+	/********************************************* Feedback message stuff ***************************************/
+
+	/**
+	 * Adds a Picture Loss Indication to the feedback queue
+	 * 
+	 * @param ssrcMediaSource
+	 * @return 0 if packet was queued, -1 if no feedback support, 1 if redundant
+	 */
+	public int fbPictureLossIndication(long ssrcMediaSource) {
+		int ret = 0;
+
+		if (this.rtcpAVPFIntf == null)
+			return -1;
+
+		RtcpPktPSFB pkt = new RtcpPktPSFB(this.ssrc, ssrcMediaSource);
+		pkt.makePictureLossIndication();
+		ret = this.rtcpSession.addToFbQueue(ssrcMediaSource, pkt);
+		if (ret == 0)
+			this.rtcpSession.wakeSenderThread(ssrcMediaSource);
+		return ret;
+	}
+
+	/**
+	 * Adds a Slice Loss Indication to the feedback queue
+	 * 
+	 * @param ssrcMediaSource
+	 * @param sliFirst
+	 *            macroblock (MB) address of the first lost macroblock
+	 * @param sliNumber
+	 *            number of lost macroblocks
+	 * @param sliPictureId
+	 *            six least significant bits of the codec-specific identif
+	 * @return 0 if packet was queued, -1 if no feedback support, 1 if redundant
+	 */
+	public int fbSlicLossIndication(long ssrcMediaSource, int[] sliFirst,
+			int[] sliNumber, int[] sliPictureId) {
+		int ret = 0;
+		if (this.rtcpAVPFIntf == null)
+			return -1;
+
+		RtcpPktPSFB pkt = new RtcpPktPSFB(this.ssrc, ssrcMediaSource);
+		pkt.makeSliceLossIndication(sliFirst, sliNumber, sliPictureId);
+
+		ret = this.rtcpSession.addToFbQueue(ssrcMediaSource, pkt);
+		if (ret == 0)
+			this.rtcpSession.wakeSenderThread(ssrcMediaSource);
+		return ret;
+	}
+
+	/**
+	 * Adds a Reference Picture Selection Indication to the feedback queue
+	 * 
+	 * @param ssrcMediaSource
+	 * @param bitPadding
+	 *            number of padded bits at end of bitString
+	 * @param payloadType
+	 *            RTP payload type for codec
+	 * @param bitString
+	 *            RPSI information as natively defined by the video codec
+	 * @return 0 if packet was queued, -1 if no feedback support, 1 if redundant
+	 */
+	public int fbRefPictureSelIndic(long ssrcMediaSource, int bitPadding,
+			int payloadType, byte[] bitString) {
+		int ret = 0;
+
+		if (this.rtcpAVPFIntf == null)
+			return -1;
+
+		RtcpPktPSFB pkt = new RtcpPktPSFB(this.ssrc, ssrcMediaSource);
+		pkt.makeRefPictureSelIndic(bitPadding, payloadType, bitString);
+		ret = this.rtcpSession.addToFbQueue(ssrcMediaSource, pkt);
+		if (ret == 0)
+			this.rtcpSession.wakeSenderThread(ssrcMediaSource);
+		return ret;
+	}
+
+	/**
+	 * Adds a Picture Loss Indication to the feedback queue
+	 * 
+	 * @param ssrcMediaSource
+	 * @param bitString
+	 *            the original application message
+	 * @return 0 if packet was queued, -1 if no feedback support, 1 if redundant
+	 */
+	public int fbAppLayerFeedback(long ssrcMediaSource, byte[] bitString) {
+		int ret = 0;
+
+		if (this.rtcpAVPFIntf == null)
+			return -1;
+
+		RtcpPktPSFB pkt = new RtcpPktPSFB(this.ssrc, ssrcMediaSource);
+		pkt.makeAppLayerFeedback(bitString);
+		ret = this.rtcpSession.addToFbQueue(ssrcMediaSource, pkt);
+		if (ret == 0)
+			this.rtcpSession.wakeSenderThread(ssrcMediaSource);
+		return ret;
+	}
+
+	/**
+	 * Adds a RTP Feedback packet to the feedback queue.
+	 * 
+	 * These are mostly used for NACKs.
+	 * 
+	 * @param ssrcMediaSource
+	 * @param FMT
+	 *            the Feedback Message Subtype
+	 * @param PID
+	 *            RTP sequence numbers of lost packets
+	 * @param BLP
+	 *            bitmask of following lost packets, shared index with PID
+	 * @return 0 if packet was queued, -1 if no feedback support, 1 if redundant
+	 */
+	public int fbPictureLossIndication(long ssrcMediaSource, int FMT,
+			int[] PID, int[] BLP) {
+		int ret = 0;
+
+		if (this.rtcpAVPFIntf == null)
+			return -1;
+
+		RtcpPktRTPFB pkt = new RtcpPktRTPFB(this.ssrc, ssrcMediaSource, FMT,
+				PID, BLP);
+		ret = this.rtcpSession.addToFbQueue(ssrcMediaSource, pkt);
+		if (ret == 0)
+			this.rtcpSession.wakeSenderThread(ssrcMediaSource);
+		return ret;
+	}
+
+	/**
+	 * Fetches the next sequence number for RTP packets.
+	 * 
+	 * @return the next sequence number
+	 */
+	private int getNextSeqNum() {
+		seqNum++;
+		// 16 bit number
+		if (seqNum > 65536) {
+			seqNum = 0;
+		}
+		return seqNum;
+	}
+
+	/**
+	 * Initializes a random variable
+	 * 
+	 */
+	private void createRandom() {
+		this.random = new Random(System.currentTimeMillis()
+				+ Thread.currentThread().getId()
+				- Thread.currentThread().hashCode() + this.cname.hashCode());
+	}
+
+	/**
+	 * Generates a random sequence number
+	 */
+	private void generateSeqNum() {
+		if (this.random == null)
+			createRandom();
+
+		seqNum = this.random.nextInt();
+		if (seqNum < 0)
+			seqNum = -seqNum;
+		while (seqNum > 65535) {
+			seqNum = seqNum / 10;
+		}
+	}
+
+	/**
+	 * Generates a random SSRC
+	 */
+	private void generateSsrc() {
+		if (this.random == null)
+			createRandom();
+
+		// Set an SSRC
+		this.ssrc = this.random.nextInt();
+		if (this.ssrc < 0) {
+			this.ssrc = this.ssrc * -1;
+		}
+	}
+
+	/**
+	 * Resolve an SSRC conflict.
+	 * 
+	 * Also increments the SSRC conflict counter, after 5 conflicts it is
+	 * assumed there is a loop somewhere and the session will terminate.
+	 * 
+	 */
+	protected void resolveSsrcConflict() {
+		System.out
+		.println("!!!!!!! Beginning SSRC conflict resolution !!!!!!!!!");
+		this.conflictCount++;
+
+		if (this.conflictCount < 5) {
+			// Don't send any more regular packets out until we have this sorted
+			// out.
+			this.conflict = true;
+
+			// Send byes
+			rtcpSession.sendByes();
+
+			// Calculate the next delay
+			rtcpSession.calculateDelay();
+
+			// Generate a new Ssrc for ourselves
+			generateSsrc();
+
+			// Get the SDES packets out faster
+			rtcpSession.initial = true;
+
+			this.conflict = false;
+			System.out.println("SSRC conflict resolution complete");
+
+		} else {
+			System.out
+			.println("Too many conflicts. There is probably a loop in the network.");
+			this.endSession();
+		}
+	}
+}