IncomingDataQueue(3) Library Functions Manual IncomingDataQueue(3)

IncomingDataQueue - Queue for incoming RTP data packets in an RTP session.

#include <iqueue.h>

Inherits IncomingDataQueueBase, and MembershipBookkeeping.

Inherited by RTPDataQueue.


class SyncSourcesIterator
iterator through the list of synchronizations sources in this session


SyncSourcesIterator begin ()
SyncSourcesIterator end ()
const AppDataUnit * getData (uint32 stamp, const SyncSource *src=NULL)
Retreive data from a specific timestamped packet if such a packet is currently available in the receive buffer. bool isWaiting (const SyncSource *src=NULL) const
Determine if packets are waiting in the reception queue. uint32 getFirstTimestamp (const SyncSource *src=NULL) const
Get timestamp of first packet waiting in the queue. void setMinValidPacketSequence (uint8 packets)
When receiving packets from a new source, it may be convenient to reject a first few packets before we are really sure the source is valid. uint8 getDefaultMinValidPacketSequence () const
uint8 getMinValidPacketSequence () const
Get the minimun number of consecutive packets that must be received from a source before accepting its data packets. void setMaxPacketMisorder (uint16 packets)
uint16 getDefaultMaxPacketMisorder () const
uint16 getMaxPacketMisorder () const
void setMaxPacketDropout (uint16 packets)
It also prevents packets sent after a restart of the source being immediately accepted. uint16 getDefaultMaxPacketDropout () const
uint16 getMaxPacketDropout () const
void setInQueueCryptoContext (CryptoContext *cc)
Set input queue CryptoContext. void removeInQueueCryptoContext (CryptoContext *cc)
Remove input queue CryptoContext. CryptoContext * getInQueueCryptoContext (uint32 ssrc)
Get an input queue CryptoContext identified by SSRC.

Public Member Functions inherited from IncomingDataQueueBase
size_t getDefaultMaxRecvPacketSize () const
size_t getMaxRecvPacketSize () const
void setMaxRecvPacketSize (size_t maxsize)

Public Member Functions inherited from RTPQueueBase
bool setPayloadFormat (const PayloadFormat &pf)
Set the payload format in use, for timing and payload type identification purposes. uint32 getLocalSSRC () const
uint32 getCurrentRTPClockRate () const
Get the clock rate in RTP clock units (for instance, 8000 units per second for PCMU, or 90000 units per second for MP2T). PayloadType getCurrentPayloadType () const
timeval getInitialTime () const


static size_t getDefaultMembersSize ()


IncomingDataQueue (uint32 size)
virtual ~IncomingDataQueue ()
bool checkSSRCInIncomingRTPPkt (SyncSourceLink &sourceLink, bool is_new, InetAddress &na, tpport_t tp)
Apply collision and loop detection and correction algorithm when receiving RTP data packets. void setSourceExpirationPeriod (uint8 intervals)
Set the number of RTCP intervals that the stack will wait to change the state of a source from stateActive to stateInactive, or to delete the source after being in stateInactive. virtual size_t takeInDataPacket ()
This function is used by the service thread to process the next incoming packet and place it in the receive list. void renewLocalSSRC ()
IncomingDataQueue::IncomingRTPPktLink * getWaiting (uint32 timestamp, const SyncSource *src=NULL)
This is used to fetch a packet in the receive queue and to expire packets older than the current timestamp. bool recordReception (SyncSourceLink &srcLink, const IncomingRTPPkt &pkt, const timeval recvtime)
Log reception of a new RTP packet from this source. void recordExtraction (const IncomingRTPPkt &pkt)
Log extraction of a packet from this source from the scheduled reception queue. void purgeIncomingQueue ()
virtual void onNewSyncSource (const SyncSource &)
Virtual called when a new synchronization source has joined the session. virtual bool onRTPPacketRecv (IncomingRTPPkt &)
A virtual function to support parsing of arriving packets to determine if they should be kept in the queue and to dispatch events. virtual void onExpireRecv (IncomingRTPPkt &)
A hook to filter packets in the receive queue that are being expired. virtual bool onSRTPPacketError (IncomingRTPPkt &pkt, int32 errorCode)
A hook that gets called if the decoding of an incoming SRTP was erroneous. virtual bool end2EndDelayed (IncomingRTPPktLink &)
bool insertRecvPacket (IncomingRTPPktLink *packetLink)
Insert a just received packet in the queue (both general and source specific queues). virtual size_t recvData (unsigned char *buffer, size_t length, InetHostAddress &host, tpport_t &port)=0
This function performs the physical I/O for reading a packet from the source. virtual size_t getNextDataPacketSize () const =0

Protected Member Functions inherited from IncomingDataQueueBase
IncomingDataQueueBase ()
virtual ~IncomingDataQueueBase ()

Protected Member Functions inherited from RTPQueueBase
RTPQueueBase (uint32 *ssrc=NULL)
void setLocalSSRC (uint32 ssrc)
uint32 getLocalSSRCNetwork () const
virtual ~RTPQueueBase ()
virtual size_t dispatchBYE (const std::string &)
A plugin point for posting of BYE messages.

Protected Member Functions inherited from MembershipBookkeeping
MembershipBookkeeping (uint32 initialSize=defaultMembersHashSize)
The initial size is a hint to allocate the resources needed in order to keep the members' identifiers and associated information. virtual ~MembershipBookkeeping ()
Purges all RTPSource structures created during the session, as well as the hash table and the list of sources. SyncSourceLink * getLink (const SyncSource &source) const
bool isMine (const SyncSource &source) const
Get whether a synchronization source is recorded in this membership controller. bool isRegistered (uint32 ssrc)
Returns whether there is already a synchronizacion source with 'ssrc' SSRC identifier. SyncSourceLink * getSourceBySSRC (uint32 ssrc, bool &created)
Get the description of a source by its ssrc identifier. bool BYESource (uint32 ssrc)
Mark the source identified by ssrc as having sent a BYE packet. bool removeSource (uint32 ssrc)
Remove the description of the source identified by ssrc SyncSourceLink * getFirst ()
SyncSourceLink * getLast ()
uint32 getMembersCount ()
void setMembersCount (uint32 n)
uint32 getSendersCount ()


size_t getDefaultMembersHashSize ()

Protected Member Functions inherited from SyncSourceHandler
SyncSourceHandler ()
virtual ~SyncSourceHandler ()


void * getLink (const SyncSource &source) const
This requires SyncSource - SyncSourceHandler friendship. void setLink (SyncSource &source, void *link)
void setParticipant (SyncSource &source, Participant &p)
void setState (SyncSource &source, SyncSource::State ns)
void setSender (SyncSource &source, bool active)
void setDataTransportPort (SyncSource &source, tpport_t p)
void setControlTransportPort (SyncSource &source, tpport_t p)
void setNetworkAddress (SyncSource &source, InetAddress addr)

Protected Member Functions inherited from ParticipantHandler
ParticipantHandler ()
virtual ~ParticipantHandler ()


void setSDESItem (Participant *part, SDESItemType item, const std::string &val)
void setPRIVPrefix (Participant *part, const std::string val)

Protected Member Functions inherited from ApplicationHandler
ApplicationHandler ()
virtual ~ApplicationHandler ()


void addParticipant (RTPApplication &app, Participant &part)
void removeParticipant (RTPApplication &app, RTPApplication::ParticipantLink *pl)

Protected Member Functions inherited from ConflictHandler
ConflictHandler ()
virtual ~ConflictHandler ()


ConflictingTransportAddress * searchDataConflict (InetAddress na, tpport_t dtp)
ConflictingTransportAddress * searchControlConflict (InetAddress na, tpport_t ctp)
void updateConflict (ConflictingTransportAddress &ca)
void addConflict (const InetAddress &na, tpport_t dtp, tpport_t ctp)


ThreadLock recvLock
IncomingRTPPktLink * recvFirst
IncomingRTPPktLink * recvLast
uint8 minValidPacketSequence
uint16 maxPacketMisorder
uint16 maxPacketDropout
uint8 sourceExpirationPeriod
Mutex cryptoMutex
std::list< CryptoContext * > cryptoContexts

Protected Attributes inherited from ConflictHandler
ConflictingTransportAddress * firstConflict
ConflictingTransportAddress * lastConflict


static const uint8 defaultMinValidPacketSequence
static const uint16 defaultMaxPacketMisorder
static const uint16 defaultMaxPacketDropout
static const size_t defaultMembersSize

Static Protected Attributes inherited from MembershipBookkeeping
static const size_t defaultMembersHashSize
static const uint32 SEQNUMMOD

Queue for incoming RTP data packets in an RTP session.

Author

Federico Montesino Pouzols fedemp@altern.org

Parameters

size initial size of the membership table.

SyncSourcesIterator IncomingDataQueue::begin () [inline]

Apply collision and loop detection and correction algorithm when receiving RTP data packets. Follows section 8.2 in draft-ietf-avt-rtp-new.

Parameters

sourceLink link to the source object.
is_new whether the source has been just recorded.
na data packet network address.
tp data packet source transport port.

Returns

whether the packet must not be discarded.

SyncSourcesIterator IncomingDataQueue::end () [inline]

Retreive data from a specific timestamped packet if such a packet is currently available in the receive buffer.

Parameters

stamp Data unit timestamp.
src Optional synchronization source selector.

Returns

data retrieved from the reception buffer.

Return values

null pointer if no packet with such timestamp is available.

Examples
audiorx.cpp, rtpduphello.cpp, rtphello.cpp, and rtplisten.cpp.

Get timestamp of first packet waiting in the queue.

Parameters

src optional source selector.

Returns

timestamp of first arrival packet.

Examples
audiorx.cpp, rtpduphello.cpp, rtphello.cpp, and rtplisten.cpp.

CryptoContext * IncomingDataQueue::getInQueueCryptoContext (uint32 ssrc)

Get an input queue CryptoContext identified by SSRC.

Parameters

ssrc Request CryptoContext for this incoming SSRC

Returns

Pointer to CryptoContext of the SSRC of NULL if no context available for this SSRC.

Get the minimun number of consecutive packets that must be received from a source before accepting its data packets.

Implemented in RTPDuplex, TRTPSessionBase< RTPDataChannel, RTCPChannel, ServiceQueue >, and TRTPSessionBase< DualRTPUDPIPv4Channel, DualRTPUDPIPv4Channel, AVPQueue >.

IncomingDataQueue::IncomingRTPPktLink * IncomingDataQueue::getWaiting (uint32 timestamp, const SyncSource * src = NULL) [protected]

This is used to fetch a packet in the receive queue and to expire packets older than the current timestamp.

Returns

packet buffer object for current timestamp if found.

Parameters

timestamp timestamp requested.
src optional source selector

Note

if found, the packet is removed from the reception queue

Insert a just received packet in the queue (both general and source specific queues). If the packet was already in the queue (same SSRC and sequence number), it is not inserted but deleted.

Parameters

packetLink link to a packet just received and generally validated and processed by onRTPPacketRecv.

Returns

whether the packet was successfully inserted.

Return values

false when the packet is duplicated (there is already a packet from the same source with the same timestamp).
true when the packet is not duplicated.

Determine if packets are waiting in the reception queue.

Parameters

src Optional synchronization source selector.

Returns

True if packets are waiting.

A hook to filter packets in the receive queue that are being expired. This hook may be used to do some application specific processing on expired packets before they are deleted.

Parameters

- packet expired from the recv queue.

Virtual called when a new synchronization source has joined the session.

Parameters

- new synchronization source

Examples
rtplisten.cpp.

A virtual function to support parsing of arriving packets to determine if they should be kept in the queue and to dispatch events. A generic header validity check (as specified in RFC 1889) is performed on every incoming packet. If the generic check completes successfully, this method is called before the packet is actually inserted into the reception queue.

May be used to perform additional validity checks or to do some application specific processing.

Parameters

- packet just received.

Returns

true if packet is kept in the incoming packets queue.

A hook that gets called if the decoding of an incoming SRTP was erroneous.

Parameters

pkt The SRTP packet with error.
errorCode The error code: -1 - SRTP authentication failure, -2 - replay check failed

Returns

True: put the packet in incoming queue for further processing by the applications; false: dismiss packet. The default implementation returns false.

Log extraction of a packet from this source from the scheduled reception queue.

Parameters

pkt Packet extracted from the queue.

Log reception of a new RTP packet from this source. Usually updates data such as the packet counter, the expected sequence number for the next packet and the time the last packet was received at.

Parameters

srcLink Link structure for the synchronization source of this packet.
pkt Packet just created and to be logged.
recvtime Reception time.

Returns

whether, according to the source state and statistics, the packet is considered valid and must be inserted in the incoming packets queue.

This function performs the physical I/O for reading a packet from the source. It is a virtual that is overridden in the derived class.

Returns

number of bytes read.

Parameters

buffer of read packet.
length of data to read.
host address of source.
port number of source.

Implemented in RTPDuplex, TRTPSessionBase< RTPDataChannel, RTCPChannel, ServiceQueue >, and TRTPSessionBase< DualRTPUDPIPv4Channel, DualRTPUDPIPv4Channel, AVPQueue >.

Remove input queue CryptoContext. The endQueue method (provided by RTPQueue) also deletes all registered CryptoContexts.

Parameters

cc Pointer to initialized CryptoContext to remove. If pointer if NULL then delete the whole queue

Reimplemented from RTPQueueBase.

Reimplemented in RTPDataQueue.

Set input queue CryptoContext. The endQueue method (provided by RTPQueue) deletes all registered CryptoContexts.

Parameters

cc Pointer to initialized CryptoContext.

It also prevents packets sent after a restart of the source being immediately accepted.

When receiving packets from a new source, it may be convenient to reject a first few packets before we are really sure the source is valid. This method sets how many data packets must be received in sequence before the source is considered valid and the stack starts to accept its packets.

Note

the default (see defaultMinValidPacketSequence()) value for this parameter is 0, so that no packets are rejected (data packets are accepted from the first one).

this validation is performed after the generic header validation and the additional validation done in onRTPPacketRecv().

if any valid RTCP packet is received from this source, it will be immediatly considered valid regardless of the number of sequential data packets received.

Parameters

packets number of sequential packet required

Set the number of RTCP intervals that the stack will wait to change the state of a source from stateActive to stateInactive, or to delete the source after being in stateInactive. Note that this value should be uniform accross all participants and SHOULD be fixed for a particular profile.

Parameters

intervals number of RTCP report intervals

Note

If RTCP is not being used, the RTCP interval is assumed to be the default: 5 seconds.

The default for this value is, as RECOMMENDED, 5.

This function is used by the service thread to process the next incoming packet and place it in the receive list.

Returns

number of payload bytes received. <0 if error.

Reimplemented in SingleThreadRTPSession< RTPDataChannel, RTCPChannel, ServiceQueue >.

IncomingRTPPktLink* IncomingDataQueue::recvFirst [protected]

IncomingRTPPktLink * IncomingDataQueue::recvLast [protected]

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