/*
* @(#)RTCPSenderInfo.java
* Created: 2005-04-21
* Version: 2-0-alpha
* 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;
/**
* Represents the sender info part of the RTCP SR Packet
*
* @author Andrew G D Rowley
* @author Christian Vincenot
* @version 1-1-alpha
*/
public class RTCPSenderInfo {
/**
* The size of the sender info
*/
public static final int SIZE = 20;
// baseline NTP time if bit-0=0 -> 7-Feb-2036 @ 06:28:16 UTC
private static final long MSB_0_BASE_TIME = 2085978496000L;
// baseline NTP time if bit-0=1 -> 1-Jan-1900 @ 01:00:00 UTC
public static final long MSB_1_BASE_TIME = -2208988800000L;
// The Most Significant word of the timestamp
private long ntpTimestampMSW = 0;
// The Least Significant word of the timestamp
private long ntpTimestampLSW = 0;
// The RTP timestamp
private long rtpTimestamp = 0;
// The packet count
private long packetCount = 0;
// The octet count
private long octetCount = 0;
/**
* Parses an RTCP Sender Report (SR) packet
* @param offset offset after which the RTCP SR starts
* @param length length of the packet
* @param rtcpPacket The data of the RTCP packet
* @throws IOException I/O Exception
*/
public RTCPSenderInfo(byte[] rtcpPacket, int offset, int length) throws IOException {
DataInputStream stream = new DataInputStream(new ByteArrayInputStream(
rtcpPacket, offset, length));
ntpTimestampMSW = stream.readInt() & RTPHeader.UINT_TO_LONG_CONVERT;
ntpTimestampLSW = stream.readInt() & RTPHeader.UINT_TO_LONG_CONVERT;
rtpTimestamp = stream.readInt() & RTPHeader.UINT_TO_LONG_CONVERT;
packetCount = stream.readInt() & RTPHeader.UINT_TO_LONG_CONVERT;
octetCount = stream.readInt() & RTPHeader.UINT_TO_LONG_CONVERT;
}
/**
* Returns a String reprensenting the information about the RTCP sender
* @return a String representing this object
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
String buf = "";
buf += "ntp_ts=" + getNtpTimestampMSW();
buf += " " + getNtpTimestampLSW();
buf += " rtp_ts=" + getRtpTimestamp();
buf += " packet_ct=" + getPacketCount();
buf += " octect_ct=" + getOctetCount();
return buf;
}
/**
* Returns the timestamp of the information
* @return timestamp of this information
*/
public long getTimestamp() {
long seconds = ntpTimestampMSW;
long fraction = ntpTimestampLSW;
// Use round-off on fractional part to preserve going to lower precision
fraction = Math.round(1000D * fraction / 0x100000000L);
/*
* If the most significant bit (MSB) on the seconds field is set we use
* a different time base. The following text is a quote from RFC-2030
* (SNTP v4):
*
* If bit 0 is set, the UTC time is in the range 1968-2036 and UTC time
* is reckoned from 0h 0m 0s UTC on 1 January 1900. If bit 0 is not set,
* the time is in the range 2036-2104 and UTC time is reckoned from 6h
* 28m 16s UTC on 7 February 2036.
*/
long msb = seconds & 0x80000000L;
if (msb == 0) {
// use base: 7-Feb-2036 @ 06:28:16 UTC
return MSB_0_BASE_TIME + (seconds * 1000) + fraction;
}
// use base: 1-Jan-1900 @ 01:00:00 UTC
return MSB_1_BASE_TIME + (seconds * 1000) + fraction;
}
/**
* Returns the timestamp value in seconds
* @return timestamp in seconds
*/
public double getNtpTimestampSecs() {
return (double) getTimestamp() / 1000;
}
/**
* Returns the timestamp most significant word
* @return the timestamp's most significant word
*/
public long getNtpTimestampMSW() {
return ntpTimestampMSW;
}
/**
* Returns the timestamp least significant word
* @return the timestamp's least significant word
*/
public long getNtpTimestampLSW() {
return ntpTimestampLSW;
}
/**
* Returns the RTP timestamp of this SR packet
* @return the timestamp of this RTCP packet
*/
public long getRtpTimestamp() {
return rtpTimestamp;
}
/**
* Returns the octet (cumulative) count.
* The total number of payload octets (i.e., not including header or
* padding) transmitted in RTP data packets by the sender since
* starting transmission up until the time this SR packet was
* generated. This field can be used to estimate the average
* payload data rate.
* @return the number of bytes sent until now
*/
public long getOctetCount() {
return octetCount;
}
/**
* Returns the packet (cumulative) count.
* The total number of RTP data packets transmitted by the sender
* since starting transmission up until the time this SR packet was
* generated.
* @return the number of packets sent until now
*/
public long getPacketCount() {
return packetCount;
}
}