OpalJitterBuffer Class Reference

#include <jitter.h>

Inheritance diagram for OpalJitterBuffer:


Public Member Functions
	OpalJitterBuffer (unsigned minJitterDelay, unsigned maxJitterDelay, unsigned timeUnits=8, PINDEX stackSize=30000)
virtual	~OpalJitterBuffer ()
void	PrintOn (ostream &strm) const
virtual PBoolean	OnReadPacket (RTP_DataFrame &frame, PBoolean loop)=0
void	SetDelay (unsigned minJitterDelay, unsigned maxJitterDelay)
void	UseImmediateReduction (PBoolean state)
virtual PBoolean	ReadData (RTP_DataFrame &frame)
DWORD	GetJitterTime () const
unsigned	GetTimeUnits () const
DWORD	GetPacketsTooLate () const
DWORD	GetBufferOverruns () const
DWORD	GetMaxConsecutiveMarkerBits () const
void	SetMaxConsecutiveMarkerBits (DWORD max)
virtual void	Resume (PHandleAggregator *aggregator=NULL)
	PDECLARE_NOTIFIER (PThread, OpalJitterBuffer, JitterThreadMain)
PBoolean	WaitForTermination (const PTimeInterval &t)
bool	IsEmpty ()
Protected Member Functions
void	Start (unsigned _minJitterTime, unsigned _maxJitterTime)
Entry *	GetNewest (bool pop)
Entry *	GetOldest (bool pop)
PBoolean	Init (Entry *&currentReadFrame, PBoolean &markerWarning)
PBoolean	PreRead (Entry *&currentReadFrame, PBoolean &markerWarning)
PBoolean	OnRead (Entry *&currentReadFrame, PBoolean &markerWarning, PBoolean loop)
void	DeInit (Entry *&currentReadFrame, PBoolean &markerWarning)
Protected Attributes
PINDEX	bufferSize
DWORD	minJitterTime
DWORD	maxJitterTime
DWORD	maxConsecutiveMarkerBits
unsigned	timeUnits
DWORD	currentJitterTime
DWORD	packetsTooLate
unsigned	bufferOverruns
unsigned	consecutiveBufferOverruns
DWORD	consecutiveMarkerBits
PTimeInterval	consecutiveEarlyPacketStartTime
DWORD	lastWriteTimestamp
PTimeInterval	lastWriteTick
DWORD	jitterCalc
DWORD	targetJitterTime
unsigned	jitterCalcPacketCount
bool	doJitterReductionImmediately
FrameQueue	freeFrames
FrameQueue	jitterBuffer
Entry *	currentFrame
PMutex	bufferMutex
bool	shuttingDown
bool	preBuffering
bool	firstReadData
RTP_JitterBufferAnalyser *	analyser
PThread *	jitterThread
PINDEX	jitterStackSize
Classes
class	Entry
class	FrameQueue

Detailed Description

This is an Abstract jitter buffer, which can be used simply in any application. The user is required to use a descendant of this class, and provide a "OnReadPacket" method, so that network packets can be placed in this class instance

Constructor & Destructor Documentation

OpalJitterBuffer::OpalJitterBuffer	(	unsigned	minJitterDelay,
		unsigned	maxJitterDelay,
		unsigned	timeUnits = `8`,
		PINDEX	stackSize = `30000`
	)

Constructor for this jitter buffer. The size of this buffer can be altered later with the SetDelay method

Parameters:

minJitterDelay	Minimum delay in RTP timestamp units
maxJitterDelay	Maximum delay in RTP timestamp units
timeUnits	Time units, usually 8 or 16
stackSize	Stack size for jitter thread

virtual OpalJitterBuffer::~OpalJitterBuffer ( ) [virtual]

Destructor, which closes this down and deletes the internal list of frames

Member Function Documentation

void OpalJitterBuffer::PrintOn ( ostream & strm ) const

Report the statistics for this jitter instance

virtual PBoolean OpalJitterBuffer::OnReadPacket	(	RTP_DataFrame &	frame,
		PBoolean	loop
	)			`[pure virtual]`

This method is where this OpalJitterBuffer collects data from the outside world. A descendant class of OpalJitterBuffer will override this method

Returns:: PTrue on successful read, PFalse on faulty read.

Parameters:

frame	Frame read from the RTP session
loop	If PTrue, loop as long as data is available, if PFalse, only process once

Implemented in RTP_JitterBuffer.

void OpalJitterBuffer::SetDelay	(	unsigned	minJitterDelay,
		unsigned	maxJitterDelay
	)

Set the maximum delay the jitter buffer will operate to.

Parameters:

minJitterDelay	Minimum delay in RTP timestamp units
maxJitterDelay	Maximum delay in RTP timestamp units

void OpalJitterBuffer::UseImmediateReduction ( PBoolean state ) [inline]

virtual PBoolean OpalJitterBuffer::ReadData ( RTP_DataFrame & frame ) [virtual]

Read a data frame from the RTP channel. Any control frames received are dispatched to callbacks and are not returned by this function. It will block until a data frame is available or an error occurs.

Parameters:

frame

Frame read from the RTP session

DWORD OpalJitterBuffer::GetJitterTime ( ) const [inline]

Get current delay for jitter buffer.

unsigned OpalJitterBuffer::GetTimeUnits ( ) const [inline]

Get time units.

DWORD OpalJitterBuffer::GetPacketsTooLate ( ) const [inline]

Get total number received packets too late to go into jitter buffer.

DWORD OpalJitterBuffer::GetBufferOverruns ( ) const [inline]

Get total number received packets that overran the jitter buffer.

DWORD OpalJitterBuffer::GetMaxConsecutiveMarkerBits ( ) const [inline]