--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jlibrtp/RtcpPkt.java	Fri Nov 20 19:29:42 2009 +0100
@@ -0,0 +1,143 @@
+/**
+ * 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.InetAddress;
+
+/**
+ * Common RTCP packet headers.
+ * 
+ * @author Arne Kepp
+ */
+public class RtcpPkt {
+	/** Whether a problem has been encountered during parsing */
+	protected int problem = 0;
+	/** The version, always 2, 2 bits */
+	protected int version = 2;
+	/** Padding , 1 bit */
+	protected int padding = 0;
+	/** Number of items, e.g. receiver report blocks. Usage may vary. 5 bits */
+	protected int itemCount = 0;
+	/** The type of RTCP packet, 8 bits */
+	protected int packetType = -1;
+	/** The length of the RTCP packet, in 32 bit blocks minus 1. 16 bits */
+	protected int length = -1;
+	/** The ssrc that sent this, usually dictated by RTP Session */
+	protected long ssrc = -1;
+
+	/** Contains the actual data (eventually) */
+	protected byte[] rawPkt = null;
+
+	/** Only used for feedback messages: Time message was generated */
+	protected long time = -1;
+	/** Only used for feedback message: Whether this packet was received */
+	protected boolean received = false;
+
+	/**
+	 * Parses the common header of an RTCP packet
+	 * 
+	 * @param start
+	 *            where in this.rawPkt the headers start
+	 * @return true if parsing succeeded and header cheks
+	 */
+	protected boolean parseHeaders(int start) {
+		version = ((rawPkt[start + 0] & 0xC0) >>> 6);
+		padding = ((rawPkt[start + 0] & 0x20) >>> 5);
+		itemCount = (rawPkt[start + 0] & 0x1F);
+		packetType = (int) rawPkt[start + 1];
+		if (packetType < 0) {
+			packetType += 256;
+		}
+		length = StaticProcs.bytesToUIntInt(rawPkt, start + 2);
+
+		if (RTPSession.rtpDebugLevel > 9) {
+			System.out.println(" <-> RtcpPkt.parseHeaders() version:" + version
+					+ " padding:" + padding + " itemCount:" + itemCount
+					+ " packetType:" + packetType + " length:" + length);
+		}
+
+		if (packetType > 207 || packetType < 200)
+			System.out
+					.println("RtcpPkt.parseHeaders problem discovered, packetType "
+							+ packetType);
+
+		if (version == 2 && length < 65536) {
+			return true;
+		} else {
+			System.out
+					.println("RtcpPkt.parseHeaders() failed header checks, check size and version");
+			this.problem = -1;
+			return false;
+		}
+	}
+
+	/**
+	 * Writes the common header of RTCP packets. The values should be filled in
+	 * when the packet is initiliazed and this function called at the very end
+	 * of .encode()
+	 */
+	protected void writeHeaders() {
+		byte aByte = 0;
+		aByte |= (version << 6);
+		aByte |= (padding << 5);
+		aByte |= (itemCount);
+		rawPkt[0] = aByte;
+		aByte = 0;
+		aByte |= packetType;
+		rawPkt[1] = aByte;
+		if (rawPkt.length % 4 != 0)
+			System.out
+					.println("!!!! RtcpPkt.writeHeaders() rawPkt was not a multiple of 32 bits / 4 octets!");
+		StaticProcs.uIntIntToByteWord((rawPkt.length / 4) - 1, rawPkt, 2);
+	}
+
+	/**
+	 * This is just a dummy to make Eclipse complain less.
+	 */
+	protected void encode() {
+		System.out.println("RtcpPkt.encode() should never be invoked!! "
+				+ this.packetType);
+	}
+
+	/**
+	 * Check whether this packet came from the source we expected.
+	 * 
+	 * Not currently used!
+	 * 
+	 * @param adr
+	 *            address that packet came from
+	 * @param partDb
+	 *            the participant database for the session
+	 * @return true if this packet came from the expected source
+	 */
+	protected boolean check(InetAddress adr, ParticipantDatabase partDb) {
+		// Multicast -> We have to be naive
+		if (partDb.rtpSession.mcSession
+				&& adr.equals(partDb.rtpSession.mcGroup))
+			return true;
+
+		// See whether this participant is known
+		Participant part = partDb.getParticipant(this.ssrc);
+		if (part != null && part.rtcpAddress.getAddress().equals(adr))
+			return true;
+
+		// If not, we should look for someone without SSRC with his ip-address?
+		return false;
+	}
+}