IncomingDataQueue Class Reference
[Generic RTP input queues., Generic RTP input queues.]

Queue for incoming RTP data packets in an RTP session. More...

#include <iqueue.h>

Inheritance diagram for IncomingDataQueue:

List of all members.


Public Member Functions
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
Static Public Member Functions
static size_t	getDefaultMembersSize ()
Protected Member Functions
	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.
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	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 Attributes
ThreadLock	recvLock
IncomingRTPPktLink *	recvFirst
IncomingRTPPktLink *	recvLast
uint8	minValidPacketSequence
uint16	maxPacketMisorder
uint16	maxPacketDropout
uint8	sourceExpirationPeriod
Static Protected Attributes
static const uint8	defaultMinValidPacketSequence
static const uint16	defaultMaxPacketMisorder
static const uint16	defaultMaxPacketDropout
static const size_t	defaultMembersSize
Classes
class	SyncSourcesIterator
	iterator through the list of synchronizations sources in this session More...

Detailed Description

Queue for incoming RTP data packets in an RTP session.

Author:: Federico Montesino Pouzols <fedemp@altern.org>

Constructor & Destructor Documentation

IncomingDataQueue::IncomingDataQueue ( uint32 size ) [protected]

Parameters:

size initial size of the membership table.

virtual IncomingDataQueue::~IncomingDataQueue ( ) [inline, protected, virtual]

Member Function Documentation

SyncSourcesIterator IncomingDataQueue::begin ( ) [inline]

bool IncomingDataQueue::checkSSRCInIncomingRTPPkt ( SyncSourceLink & sourceLink,

bool is_new,

InetAddress & na,

tpport_t tp

) [protected]

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]

virtual bool IncomingDataQueue::end2EndDelayed ( IncomingRTPPktLink & ) [inline, protected, virtual]

const AppDataUnit* IncomingDataQueue::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.

Parameters:

stamp Data unit timestamp.

src Optional synchronization source selector.

Returns:
data retrieved from the reception buffer.

uint16 IncomingDataQueue::getDefaultMaxPacketDropout ( ) const [inline]

uint16 IncomingDataQueue::getDefaultMaxPacketMisorder ( ) const [inline]

static size_t IncomingDataQueue::getDefaultMembersSize ( ) [inline, static]

uint8 IncomingDataQueue::getDefaultMinValidPacketSequence ( ) const [inline]

uint32 IncomingDataQueue::getFirstTimestamp ( const SyncSource * src = NULL ) const

Get timestamp of first packet waiting in the queue.

Parameters:

src optional source selector.

Returns:
timestamp of first arrival packet.

uint16 IncomingDataQueue::getMaxPacketDropout ( ) const [inline]

uint16 IncomingDataQueue::getMaxPacketMisorder ( ) const [inline]

uint8 IncomingDataQueue::getMinValidPacketSequence ( ) const [inline]

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

virtual size_t IncomingDataQueue::getNextDataPacketSize ( ) const [protected, pure virtual]

Implemented in RTPDuplex.

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

bool IncomingDataQueue::insertRecvPacket ( IncomingRTPPktLink * packetLink ) [protected]

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.

bool IncomingDataQueue::isWaiting ( const SyncSource * src = NULL ) const

Determine if packets are waiting in the reception queue.

Parameters:

src Optional synchronization source selector.

Returns:
True if packets are waiting.

virtual void IncomingDataQueue::onExpireRecv ( IncomingRTPPkt & ) [inline, protected, virtual]

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 void IncomingDataQueue::onNewSyncSource ( const SyncSource & ) [inline, protected, virtual]

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

Parameters:

- new synchronization source

virtual bool IncomingDataQueue::onRTPPacketRecv ( IncomingRTPPkt & ) [inline, protected, virtual]

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 succesfully, 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.

void IncomingDataQueue::purgeIncomingQueue ( ) [protected]

void IncomingDataQueue::recordExtraction ( const IncomingRTPPkt & pkt ) [protected]

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

Parameters:

pkt Packet extracted from the queue.

bool IncomingDataQueue::recordReception ( SyncSourceLink & srcLink,

const IncomingRTPPkt & pkt,

const timeval recvtime

) [protected]

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.

virtual size_t IncomingDataQueue::recvData ( unsigned char * buffer,

size_t length,

InetHostAddress & host,

tpport_t & port

) [protected, pure virtual]

This function performs the physical I/O for reading a packet from the source.
It is a virtual that is overriden 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.

void IncomingDataQueue::renewLocalSSRC ( ) [protected, virtual]

Reimplemented from RTPQueueBase.
Reimplemented in RTPDataQueue.

void IncomingDataQueue::setMaxPacketDropout ( uint16 packets ) [inline]

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

void IncomingDataQueue::setMaxPacketMisorder ( uint16 packets ) [inline]

void IncomingDataQueue::setMinValidPacketSequence ( uint8 packets ) [inline]

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

void IncomingDataQueue::setSourceExpirationPeriod ( uint8 intervals ) [inline, protected]

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.

size_t IncomingDataQueue::takeInDataPacket ( ) [protected]

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.