/*
* @(#)RTCPFeedback.java
* Created: 02-Dec-2005
* Version: 1-1-alpha3
* Copyright (c) 2005-2006, University of Manchester All rights reserved.
* Andrew G D Rowley
* Christian Vincenot <sipcom@cyberspace7.net>
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer. Redistributions in binary
* form must reproduce the above copyright notice, this list of conditions and
* the following disclaimer in the documentation and/or other materials
* provided with the distribution. Neither the name of the University of
* Manchester nor the names of its contributors may be used to endorse or
* promote products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package net.sf.fmj.media.rtp;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import javax.media.rtp.rtcp.Feedback;
/**
* Represents an RTCP Feedback report
* @author Andrew G D Rowley
* @author Christian Vincenot
* @version 1-1-alpha3
*/
public class RTCPFeedback implements Feedback {
/**
* The size of a feedback report in bytes
*/
public static final int SIZE = 24;
// The SSRC that this is feedback for
private long ssrc = 0;
// The fraction of packets lost
private int fractionLost = 0;
// The number of packets lost
private long numLost = 0;
// The extended highest sequence number
private long xtndSeqNum = 0;
// The jitter
private long jitter = 0;
// The LSR
private long lsr = 0;
// The DLSR
private long dlsr = 0;
/**
* Creates a new RTCP Feedback report
* @param data The data to read from
* @param offset The offset into the data where the report starts
* @param length The length of the report
* @throws IOException I/O Exception
*/
public RTCPFeedback(byte[] data, int offset, int length) throws IOException {
DataInputStream stream = new DataInputStream(new ByteArrayInputStream(
data, offset, length));
ssrc = stream.readInt() & RTPHeader.UINT_TO_LONG_CONVERT;
fractionLost = stream.readUnsignedByte();
numLost = (stream.readUnsignedShort() << 8) | stream.readUnsignedByte();
xtndSeqNum = stream.readInt() & RTPHeader.UINT_TO_LONG_CONVERT;
jitter = stream.readInt() & RTPHeader.UINT_TO_LONG_CONVERT;
lsr = stream.readInt() & RTPHeader.UINT_TO_LONG_CONVERT;
dlsr = stream.readInt() & RTPHeader.UINT_TO_LONG_CONVERT;
}
/**
* Returns the SSRC corresponding to the feedback.
* @return The SSRC
*/
public long getSSRC() {
return ssrc;
}
/**
* Returns the fraction of RTP data packets from source SSRC_n lost since the
* previous SR or RR packet was sent
* @return Returns the fraction of packets lost
*/
public int getFractionLost() {
return fractionLost;
}
/**
* Returns the number of RTP data packets from source SSRC_n lost since the
* previous SR or RR packet was sent. This number is a cumulatative count (like most
* of the values used in the RFC).
* @return Returns the number of packets lost
*/
public long getNumLost() {
return numLost;
}
/**
* Returns the extended highest sequence number received.
* The low 16 bits contain the highest sequence number received in an
* RTP data packet from source SSRC_n, and the most significant 16
* bits extend that sequence number with the corresponding count of
* sequence number cycles
* @return the extended highest sequence number received.
*/
public long getXtndSeqNum() {
return xtndSeqNum;
}
/**
* Returns the interarrival jitter
* An estimate of the statistical variance of the RTP data packet
* interarrival time, measured in timestamp units and expressed as an
* unsigned integer.
* @return the interarrival jitter
*/
public long getJitter() {
return jitter;
}
/**
* Returns last SR timestamp (LSR).
* @return the last SR timestamp (LSR)
*/
public long getLSR() {
return lsr;
}
/**
* Returns the delay since last SR (DLSR).
* @return the delay since last SR (DLSR)
*/
public long getDLSR() {
return dlsr;
}
}