org.jitsi.impl.neomedia.rtcp

Class RTCPTCCPacket

java.lang.Object

net.sf.fmj.media.rtp.util.Packet

net.sf.fmj.media.rtp.RTCPPacket

org.jitsi.impl.neomedia.rtcp.RTCPFBPacket

org.jitsi.impl.neomedia.rtcp.RTCPTCCPacket

public class RTCPTCCPacket
extends RTCPFBPacket

A class which represents an RTCP packet carrying transport-wide congestion control (transport-cc) feedback information. The format is defined here: https://tools.ietf.org/html/draft-holmer-rmcat-transport-wide-cc-extensions-01

  0                   1                   2                   3
  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |V=2|P|  FMT=15 |    PT=205     |           length              |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                     SSRC of packet sender                     |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                      SSRC of media source                     |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |      base sequence number     |      packet status count      |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |                 reference time                | fb pkt. count |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |          packet chunk         |         packet chunk          |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 .                                                               .
 .                                                               .
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |         packet chunk          |  recv delta   |  recv delta   |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 .                                                               .
 .                                                               .
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 |           recv delta          |  recv delta   | zero padding  |
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 

Author:

Boris Grozev, George Politis

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RTCPTCCPacket.PacketMap An ordered collection which maps sequence numbers to timestamps, the order is by the sequence number.

Field Summary

Fields

Modifier and Type	Field and Description
static int	FMT The value of the "fmt" field for a transport-cc RTCP feedback packet.
static int	MAX_PACKET_COUNT The maximum number of packets (including missing packets) to include in an RTCPTCCPacket being constructed for a list of packets.

Fields inherited from class org.jitsi.impl.neomedia.rtcp.RTCPFBPacket

fci, fmt, PSFB, RTPFB, senderSSRC, sourceSSRC

Fields inherited from class net.sf.fmj.media.rtp.RTCPPacket

APP, base, BYE, COMPOUND, RR, SDES, SR, type

Fields inherited from class net.sf.fmj.media.rtp.util.Packet

data, flags, length, offset, receiptTime, received

Constructor Summary

Constructors

Constructor and Description
RTCPTCCPacket(long senderSSRC, long sourceSSRC, RTCPTCCPacket.PacketMap packets, byte fbPacketCount, org.jitsi.utils.logging.DiagnosticContext diagnosticContext) Initializes a new RTCPTCCPacket instance with a specific "packet sender SSRC" and "media source SSRC" values, and which describes a specific set of sequence numbers.
RTCPTCCPacket(net.sf.fmj.media.rtp.RTCPCompoundPacket base) Initializes a new RTCPTCCPacket instance.

Method Summary

Modifier and Type	Method and Description
int	getFbPacketCount()
RTCPTCCPacket.PacketMap	getPackets()
static RTCPTCCPacket.PacketMap	getPackets(org.jitsi.utils.ByteArrayBuffer baf)
static RTCPTCCPacket.PacketMap	getPacketsFromFci(org.jitsi.utils.ByteArrayBuffer fciBuffer)
static long	getReferenceTime250us(org.jitsi.utils.ByteArrayBuffer fciBuffer)
static boolean	isTCCPacket(org.jitsi.utils.ByteArrayBuffer baf) Gets a boolean indicating whether or not the RTCP packet specified in the ByteArrayBuffer that is passed as an argument is a TCC packet or not.
String	toString()

Methods inherited from class org.jitsi.impl.neomedia.rtcp.RTCPFBPacket

assemble, calcLength, getFCI, getSenderSSRC, getSourceSSRC, getSourceSSRC, isPSFBPacket, isRTCPFBPacket, isRTPFBPacket, toRawPacket

Methods inherited from class net.sf.fmj.media.rtp.util.Packet

clone

Methods inherited from class java.lang.Object

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

Field Detail

MAX_PACKET_COUNT

public static final int MAX_PACKET_COUNT

The maximum number of packets (including missing packets) to include in an RTCPTCCPacket being constructed for a list of packets.

See Also:

Constant Field Values

FMT

public static final int FMT

The value of the "fmt" field for a transport-cc RTCP feedback packet.

See Also:

Constant Field Values

Constructor Detail

RTCPTCCPacket

public RTCPTCCPacket(net.sf.fmj.media.rtp.RTCPCompoundPacket base)

Initializes a new RTCPTCCPacket instance.

Parameters:

base -

RTCPTCCPacket

public RTCPTCCPacket(long senderSSRC,
                     long sourceSSRC,
                     RTCPTCCPacket.PacketMap packets,
                     byte fbPacketCount,
                     org.jitsi.utils.logging.DiagnosticContext diagnosticContext)

Initializes a new RTCPTCCPacket instance with a specific "packet sender SSRC" and "media source SSRC" values, and which describes a specific set of sequence numbers.

Parameters:

senderSSRC - the value to use for the "packet sender SSRC" field.

sourceSSRC - the value to use for the "media source SSRC" field.

packets - the set of RTP sequence numbers and their reception timestamps which this packet is to describe. Note that missing sequence numbers, as well as those mapped to a negative will be interpreted as missing (not received) packets.

fbPacketCount - the index of this feedback packet, to be used in the "fb pkt count" field.

diagnosticContext - the DiagnosticContext to use to print diagnostic information. Warning: The timestamps for the packets are expected to be in millisecond increments, which is different than the output map produced after parsing a packet! Note: this implementation is not optimized and might not always use the minimal possible number of bytes to describe a given set of packets.

Method Detail

isTCCPacket

public static boolean isTCCPacket(org.jitsi.utils.ByteArrayBuffer baf)

Gets a boolean indicating whether or not the RTCP packet specified in the ByteArrayBuffer that is passed as an argument is a TCC packet or not.

Parameters:

baf - the ByteArrayBuffer

Returns:

true if the byte array buffer holds a TCC packet, otherwise false.

getPackets

public static RTCPTCCPacket.PacketMap getPackets(org.jitsi.utils.ByteArrayBuffer baf)

Parameters:

baf - the buffer which contains the RTCP packet.

Returns:

the packets represented in an RTCP transport-cc feedback packet. Warning: the timestamps are represented in the 250µs format used by the on-the-wire format, and don't represent local time. This is different than the timestamps expected as input when constructing a packet with RTCPTCCPacket(long, long, PacketMap, byte, DiagnosticContext).

getReferenceTime250us

public static long getReferenceTime250us(org.jitsi.utils.ByteArrayBuffer fciBuffer)

Returns:

the reference time of the FCI buffer of an RTCP TCC packet. The format is 32 bits with 250µs resolution. Note that the format in the transport-wide cc draft is 24bit with 2^6ms resolution. The change in the unit facilitates the arrival time computations, as the deltas have 250µs resolution.

getPacketsFromFci

public static RTCPTCCPacket.PacketMap getPacketsFromFci(org.jitsi.utils.ByteArrayBuffer fciBuffer)

Parameters:

fciBuffer - the buffer which contains the FCI portion of the RTCP feedback packet.

Returns:

the packets represented in the FCI portion of an RTCP transport-cc feedback packet. Warning: the timestamps are represented in the 250µs format used by the on-the-wire format, and don't represent local time. This is different than the timestamps expected as input when constructing a packet with RTCPTCCPacket(long, long, PacketMap, byte, DiagnosticContext). Note that packets described as lost are NOT included in the results.

getPackets

public RTCPTCCPacket.PacketMap getPackets()

Returns:

the map of packets represented by this RTCPTCCPacket. Warning: the timestamps are represented in the 250µs format used by the on-the-wire format, and don't represent local time. This is different than the timestamps expected as input when constructing a packet with RTCPTCCPacket(long, long, PacketMap, byte, DiagnosticContext).

getFbPacketCount

public int getFbPacketCount()

Returns:

the value of the "fb packet count" field of this packet, or -1.

toString

public String toString()

Overrides:

toString in class RTCPFBPacket