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/*
* SIP Communicator, the OpenSource Java VoIP and Instant Messaging client.
*
* Distributable under LGPL license.
* See terms of license at gnu.org.
*/
package net.java.sip.communicator.impl.neomedia;
import javax.media.rtp.*;
/**
* Represents an RTCP feedback packet as described in RFC4585.
*
* @author Sebastien Vincent
*/
public class RTCPFeedbackPacket
{
/**
* Feedback message type.
*/
private int fmt = 0;
/**
* Payload type.
*/
private int payloadType = 0;
/**
* SSRC of packet sender.
*/
private long senderSSRC = 0;
/**
* SSRC of media source.
*/
private long sourceSSRC = 0;
/**
* Constructor.
*
* @param type feedback message type
* @param payloadType payload type
* @param sender sender SSRC
* @param src source SSRC
*/
public RTCPFeedbackPacket(int type, int payloadType, long sender, long src)
{
this.fmt = type;
this.payloadType = payloadType;
this.senderSSRC = sender;
this.sourceSSRC = src;
}
/**
* Write RTCP packet to output stream of a <tt>DatagramSocket</tt>.
*
* @param out <tt>OutputDataStream</tt> of a <tt>DatagramSocket</tt>
*/
public void writeTo(OutputDataStream out)
{
byte data[] = new byte[12];
byte vpfmt = (byte)((2 << 7) | (0 << 6) | (byte)fmt);
data[0] = vpfmt;
data[1] = (byte)payloadType;
/* length (in 32-bit words minus one) */
data[2] = 0;
data[3] = 2; /* common packet is 12 bytes so (12/4) - 1 */
/* sender SSRC */
data[4] = (byte)(senderSSRC >> 24);
data[5] = (byte)((senderSSRC >> 16) & 0xFF);
data[6] = (byte)((senderSSRC >> 8) & 0xFF);
data[7] = (byte)(senderSSRC & 0xFF);
/* source SSRC */
data[8] = (byte)(sourceSSRC >> 24);
data[9] = (byte)((sourceSSRC >> 16) & 0xFF);
data[10] = (byte)((sourceSSRC >> 8) & 0xFF);
data[11] = (byte)(sourceSSRC & 0xFF);
/* effective write */
out.write(data, 0, 12);
}
}
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