net.sf.fmj.media.rtp
Class RTCPFeedback

java.lang.Object
  net.sf.fmj.media.rtp.RTCPFeedback

All Implemented Interfaces:

Feedback

public class RTCPFeedback
extends java.lang.Object
implements Feedback

Represents an RTCP Feedback report

Version:

1-1-alpha3

Author:

Andrew G D Rowley, Christian Vincenot

Field Summary

static int

SIZE The size of a feedback report in bytes

Constructor Summary

RTCPFeedback(byte[] data, int offset, int length)
Creates a new RTCP Feedback report

Method Summary

long	getDLSR() Returns the delay since last SR (DLSR).
int	getFractionLost() Returns the fraction of RTP data packets from source SSRC_n lost since the previous SR or RR packet was sent
long	getJitter() 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.
long	getLSR() Returns last SR timestamp (LSR).
long	getNumLost() Returns the number of RTP data packets from source SSRC_n lost since the previous SR or RR packet was sent.
long	getSSRC() Returns the SSRC corresponding to the feedback.
long	getXtndSeqNum() Returns the extended highest sequence number received.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SIZE

public static final int SIZE

The size of a feedback report in bytes

See Also:

Constant Field Values

Constructor Detail

RTCPFeedback

public RTCPFeedback(byte[] data,
                    int offset,
                    int length)
             throws java.io.IOException

Creates a new RTCP Feedback report

Parameters:

data - The data to read from

offset - The offset into the data where the report starts

length - The length of the report

Throws:

java.io.IOException - I/O Exception

Method Detail

getSSRC

public long getSSRC()

Returns the SSRC corresponding to the feedback.

Specified by:

getSSRC in interface Feedback

Returns:

The SSRC

getFractionLost

public int getFractionLost()

Returns the fraction of RTP data packets from source SSRC_n lost since the previous SR or RR packet was sent

Specified by:

getFractionLost in interface Feedback

Returns:

Returns the fraction of packets lost

getNumLost

public long getNumLost()

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).

Specified by:

getNumLost in interface Feedback

Returns:

Returns the number of packets lost

getXtndSeqNum

public long getXtndSeqNum()

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

Specified by:

getXtndSeqNum in interface Feedback

Returns:

the extended highest sequence number received.

getJitter

public long getJitter()

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.

Specified by:

getJitter in interface Feedback

Returns:

the interarrival jitter

getLSR

public long getLSR()

Returns last SR timestamp (LSR).

Specified by:

getLSR in interface Feedback

Returns:

the last SR timestamp (LSR)

getDLSR

public long getDLSR()

Returns the delay since last SR (DLSR).

Specified by:

getDLSR in interface Feedback

Returns:

the delay since last SR (DLSR)