/**

 * 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;

/**

 * Application specific RTCP packets

 * 

 * @author Arne Kepp

 */

public class RtcpPktAPP extends RtcpPkt {

	/** Name of packet, 4 bytes ASCII */

	protected byte[] pktName = null;

	/** Data of packet */

	protected byte[] pktData = null;	

	/**

	 * Constructor for a new Application RTCP packet

	 * 

	 * @param ssrc the SSRC of the sender, presumably taken from RTPSession

	 * @param subtype the subtype of packet, application specific

	 * @param pktName byte[4] representing ASCII name of packet

	 * @param pktData the byte[4x] data that represents the message itself

	 */

	protected RtcpPktAPP(long ssrc, int subtype, byte[] pktName, byte[] pktData) {

		// Fetch all the right stuff from the database

		super.ssrc = ssrc;

		super.packetType = 204;

		super.itemCount = subtype;

		this.pktName = pktName;

		this.pktData = pktData;

	}

	/**

	 * Constructor that parses a received Application RTCP packet

	 * 

	 * @param aRawPkt the raw packet containing the date

	 * @param start where in the raw packet this packet starts

	 */

	protected RtcpPktAPP(byte[] aRawPkt, int start) {

		super.ssrc = StaticProcs.bytesToUIntLong(aRawPkt,4);

		super.rawPkt = aRawPkt;

		if(!super.parseHeaders(start) || packetType != 204 ) {

			if(RTPSession.rtpDebugLevel > 2) {

				System.out.println(" <-> RtcpPktAPP.parseHeaders() etc. problem");

			}

			super.problem = -204;

		} else {

			//System.out.println("super.length:  " + super.length);

			if(super.length > 1) {

				pktName = new byte[4];

				System.arraycopy(aRawPkt, 8, pktName, 0, 4);

			}

			if(super.length > 2) {

				pktData = new byte[(super.length+1)*4 - 12];

				System.arraycopy(aRawPkt, 12, pktData, 0, pktData.length);

			}

		}

	}

	/**

	 * Encode the packet into a byte[], saved in .rawPkt

	 * 

	 * CompRtcpPkt will call this automatically

	 */

	protected void encode() {	

		super.rawPkt = new byte[12 + this.pktData.length];

		byte[] tmp = StaticProcs.uIntLongToByteWord(super.ssrc);

		System.arraycopy(tmp, 0, super.rawPkt, 4, 4);

		System.arraycopy(this.pktName, 0, super.rawPkt, 8, 4);

		System.arraycopy(this.pktData, 0, super.rawPkt, 12, this.pktData.length);

		writeHeaders();

		//System.out.println("ENCODE: " + super.length + " " + rawPkt.length + " " + pktData.length);

	}

}