MprDejitter Class Reference

The "Dejitter" utility class. More...

#include <MprDejitter.h>

Collaboration diagram for MprDejitter:

Public Types
enum	{ MAX_RTP_PACKETS = 256 }

Public Member Functions
Creators
	MprDejitter (MpConnectionID connId=MP_INVALID_CONNECTION_ID, int streamId=-1)
	Constructor. More...
virtual	~MprDejitter ()
	Destructor. More...
Manipulators
void	reset ()
	Reset dejitter to initial state and prepare for new stream. More...
OsStatus	pushPacket (MpRtpBufPtr &pRtp)
	Add an incoming RTP packet to the dejitter pool. More...
MpRtpBufPtr	pullPacket ()
	Get next RTP packet, or NULL if none is available. More...
MpRtpBufPtr	pullPacket (RtpTimestamp timestamp, UtlBoolean *nextFrameAvailable=NULL, bool lockTimestamp=true)
	Get next RTP packet with given timestamp, or NULL if none is available. More...
void	setConnectionId (MpConnectionID connId)
	Set connection ID for debug purposes. More...
void	setStreamId (int streamId)
	Set RTP stream ID for debug purposes. More...
void	setFlowgrapName (const UtlString &fgName)
	Set flowgraph name for debug purposes. More...
Accessors
int	getNumPackets () const
	Get number of packets in buffer, arrived in time. More...
int	getNumLatePackets () const
	Get number of late packets in buffer. More...
OsStatus	getFirstPacketInfo (RtpSeq &packetSeq, RtpTimestamp &packetTime) const
	Get RTP header info. for first sequentially available packet. More...

Protected Attributes
MpRtpBufPtr	mpPackets [MAX_RTP_PACKETS]
	Buffer for incoming RTP packets. More...
int	mNumPackets
	Number of packets in buffer, arrived in time. More...
int	mNumLatePackets
	Number of packets in buffer, arrived late. More...
int	mNumDiscarded
	Number of packets overwritten with newly came packets. More...
int	mLastPushed
	Index of the last inserted packet. More...
UtlBoolean	mIsFirstPulledPacket
	Have we returned first RTP packet or not? More...
RtpSeq	mMaxPulledSeqNo
MpConnectionID	mConnectionId
	Connection ID for debug purposes. More...
int	mStreamId
	RTP stream ID for debug purposes. More...
UtlString	mFlowgraphName
	Parent flowgraph for debug purposes. More...
UtlString	mResourceName
	Resource name for debug purposes. More...

Private Member Functions
	MprDejitter (const MprDejitter &rMprDejitter)
	Copy constructor (not implemented for this class) More...
MprDejitter &	operator= (const MprDejitter &rhs)
	Assignment operator (not implemented for this class) More...

Detailed Description

The "Dejitter" utility class.

This class is not thread-safe. For thread-safety it relies on external synchronization mechanisms in MprDecode.

Member Enumeration Documentation

anonymous enum

Enumerator
MAX_RTP_PACKETS	Could be any value, power of 2 is desired.

Constructor & Destructor Documentation

MprDejitter	(	MpConnectionID	connId = MP_INVALID_CONNECTION_ID,
		int	streamId = -1
	)

Constructor.

~MprDejitter ( )

virtual

Destructor.

MprDejitter ( const MprDejitter &  rMprDejitter )

private

Copy constructor (not implemented for this class)

Member Function Documentation

void reset

(

)

Reset dejitter to initial state and prepare for new stream.

OsStatus pushPacket

(

MpRtpBufPtr &

pRtp

)

Add an incoming RTP packet to the dejitter pool.

This method places the packet to the pool depending the modulo division value.

Warning

This method swaps pRtp with some other packet in the dejitter buffer. So you should dispose pRtp pointer asap after calling this method.

Returns

OS_SUCCESS on success

OS_LIMIT_REACHED if too many codecs used in incoming RTP packets

MpRtpBufPtr pullPacket

(

)

Get next RTP packet, or NULL if none is available.

This buffer is the primary dejitter/reorder buffer for the internal codecs. Some codecs may do their own dejitter stuff too. But we can't eliminate this buffer because then out-of-order packets would just be dumped on the ground.

This buffer does NOT substitute silence packets. That is done in MpJitterBuffer called from MprDecode.

If packets arrive out of order, and the newer packet has already been pulled due to the size of the jitter buffer set by the codec, this buffer will NOT discard the out-of-order packet, but send it along anyway it is up to the codec to discard the packets it cannot use. This allows this JB to be a no-op buffer for when the commercial library is used.

If pulled packet belong to signaling codec (e.g. RFC2833 DTMF), then set isSignaling to true. Else packet will be hold for undefined amount of time, possible forever.

MpRtpBufPtr pullPacket	(	RtpTimestamp	timestamp,
		UtlBoolean *	nextFrameAvailable = NULL,
		bool	lockTimestamp = true
	)

Get next RTP packet with given timestamp, or NULL if none is available.

This version of pullPacket() works exactly the same as above version of pullPacket() with one exception: if (lockTimestamp == true) it checks every found packet's timestamp. And return NULL if there are no packets with timestamp less or equal then passed timestamp.

If pulled packet belong to signaling codec (e.g. RFC2833 DTMF), then set isSignaling to true. Else packet will be hold for undefined amount of time, possible forever.

< RTP packet we will return

void setConnectionId

(

MpConnectionID

connId

)

Set connection ID for debug purposes.

void setStreamId

(

int

streamId

)

Set RTP stream ID for debug purposes.

void setFlowgrapName

(

const UtlString &

fgName

)

Set flowgraph name for debug purposes.

int getNumPackets ( ) const

inline

Get number of packets in buffer, arrived in time.

int getNumLatePackets ( ) const

inline

Get number of late packets in buffer.

OsStatus getFirstPacketInfo	(	RtpSeq &	packetSeq,
		RtpTimestamp &	packetTime
	)		const

Get RTP header info. for first sequentially available packet.

MprDejitter& operator= ( const MprDejitter &  rhs )

private

Assignment operator (not implemented for this class)

Member Data Documentation

MpRtpBufPtr mpPackets[MAX_RTP_PACKETS]

protected

Buffer for incoming RTP packets.

int mNumPackets

protected

Number of packets in buffer, arrived in time.

int mNumLatePackets

protected

Number of packets in buffer, arrived late.

int mNumDiscarded

protected

Number of packets overwritten with newly came packets.

int mLastPushed

protected

Index of the last inserted packet.

UtlBoolean mIsFirstPulledPacket

protected

Have we returned first RTP packet or not?

RtpSeq mMaxPulledSeqNo

protected

Keep track of the last sequence number returned, so that we can distinguish out-of-order packets.

MpConnectionID mConnectionId

protected

Connection ID for debug purposes.

int mStreamId

protected

RTP stream ID for debug purposes.

UtlString mFlowgraphName

protected

Parent flowgraph for debug purposes.

UtlString mResourceName

protected

Resource name for debug purposes.