#include <channels.h>

Inheritance diagram for H323Channel:

Collaboration diagram for H323Channel:

Public Member Functions
Construction
	H323Channel (H323Connection &connection, const H323Capability &capability)

	~H323Channel ()

Overrides from PObject
virtual void	PrintOn (ostream &strm) const

Member variable access
const H323ChannelNumber &	GetNumber () const

void	SetNumber (const H323ChannelNumber &num)

const H323ChannelNumber &	GetReverseChannel () const

void	SetReverseChannel (const H323ChannelNumber &num)

OpalBandwidth	GetBandwidthUsed () const

bool	SetBandwidthUsed (OpalBandwidth bandwidth)

const H323Capability &	GetCapability () const

OpalMediaFormat	GetMediaFormat () const
	Get the media format (from capability) More...

virtual bool	UpdateMediaFormat (const OpalMediaFormat &mediaFormat)
	Update media format options. More...

Protected Member Functions
virtual void	InternalClose ()

Protected Attributes
H323EndPoint &	endpoint

H323Connection &	connection

H323Capability *	capability

H323ChannelNumber	number

H323ChannelNumber	reverseChannel

bool	opened

atomic< bool >	m_terminating

Operations
enum	Directions { IsBidirectional, IsTransmitter, IsReceiver, NumDirections }

virtual Directions	GetDirection () const =0

virtual unsigned	GetSessionID () const

virtual bool	SetSessionID (unsigned sessionID)

virtual PBoolean	GetMediaTransportAddress (OpalTransportAddress &data, OpalTransportAddress &control) const

virtual PBoolean	SetInitialBandwidth ()=0

virtual bool	PreOpen ()

virtual PBoolean	Open ()

virtual void	Close ()

PBoolean	IsOpen () const

virtual OpalMediaStreamPtr	GetMediaStream () const

virtual void	SetMediaStream (OpalMediaStreamPtr mediaStream)

virtual PBoolean	OnSendingPDU (H245_OpenLogicalChannel &openPDU) const

virtual void	OnSendOpenAck (const H245_OpenLogicalChannel &open, H245_OpenLogicalChannelAck &ack) const

virtual PBoolean	OnReceivedPDU (const H245_OpenLogicalChannel &pdu, unsigned &errorCode)

virtual PBoolean	OnReceivedAckPDU (const H245_OpenLogicalChannelAck &pdu)

virtual void	OnFlowControl (long bitRateRestriction)

virtual void	OnMiscellaneousCommand (const H245_MiscellaneousCommand_type &type)

virtual void	OnMiscellaneousIndication (const H245_MiscellaneousIndication_type &type)

virtual void	OnJitterIndication (DWORD jitter, int skippedFrameCount, int additionalBuffer)

Detailed Description

This class describes a logical channel between the two endpoints. They may be created and deleted as required in the H245 protocol.

An application may create a descendent off this class and override functions as required for operating the channel protocol.

Member Enumeration Documentation

enum H323Channel::Directions

Enumerator
IsBidirectional
IsTransmitter
IsReceiver
NumDirections

Constructor & Destructor Documentation

H323Channel::H323Channel	(	H323Connection &	connection,
		const H323Capability &	capability
	)

Create a new channel.

Parameters

connection	Connection to endpoint for channel
capability	Capability channel is using

H323Channel::~H323Channel ( )

Destroy new channel. To avoid usage of deleted objects in background threads, this waits for the H323LogicalChannelThread to terminate before continuing.

Member Function Documentation

virtual void H323Channel::Close ( )

virtual

This is called to clean up any threads on connection termination.

OpalBandwidth H323Channel::GetBandwidthUsed ( ) const

inline

Get the bandwidth used by the channel in 100's of bits/sec.

const H323Capability& H323Channel::GetCapability ( ) const

inline

Get the capability that created this channel.

References capability.

virtual Directions H323Channel::GetDirection ( ) const

pure virtual

Indicate the direction of the channel. Return if the channel is bidirectional, or unidirectional, and which direction for the latter case.

Implemented in H323BidirectionalChannel, and H323UnidirectionalChannel.

OpalMediaFormat H323Channel::GetMediaFormat ( ) const

Get the media format (from capability)

virtual OpalMediaStreamPtr H323Channel::GetMediaStream ( ) const

virtual

Get the media stream associated with this logical channel.

If the argument is set to true, the mediaStream is about to be deleted so all internal references to the mediaStream must be removed.

The default behaviour returns NULL.

Reimplemented in H323UnidirectionalChannel.

virtual PBoolean H323Channel::GetMediaTransportAddress	(	OpalTransportAddress &	data,
		OpalTransportAddress &	control
	)		const

virtual

Get the media transport address for the connection. This is primarily used to determine if media bypass is possible for the call between two connections.

The default behaviour returns false.

Parameters

data	Data channel address
control	Control channel address

Reimplemented in H323_RTPChannel.

const H323ChannelNumber& H323Channel::GetNumber ( ) const

inline

Get the number of the channel.

References number.

const H323ChannelNumber& H323Channel::GetReverseChannel ( ) const

inline

Get the number of the reverse channel (if present).

References reverseChannel.

virtual unsigned H323Channel::GetSessionID ( ) const

virtual

Indicate the session number of the channel. Return session for channel. This is primarily for use by RTP based channels, for channels for which the concept of a session is not meaningfull, the default simply returns 0.

Reimplemented in H323DataChannel, and H323_RTPChannel.

virtual void H323Channel::InternalClose ( )

protectedvirtual

Reimplemented in H323DataChannel, and H323UnidirectionalChannel.

PBoolean H323Channel::IsOpen ( ) const

inline

Indicate if has been opened.

References m_terminating, and opened.

virtual void H323Channel::OnFlowControl ( long bitRateRestriction )

virtual

Limit bit flow for the logical channel. The default behaviour passes this on to the codec if not NULL.

Parameters

bitRateRestriction Bit rate limitation

virtual void H323Channel::OnJitterIndication	(	DWORD	jitter,
		int	skippedFrameCount,
		int	additionalBuffer
	)

virtual

Limit bit flow for the logical channel. The default behaviour does nothing.

Parameters

jitter	Estimated received jitter in microseconds
skippedFrameCount	Frames skipped by decodec
additionalBuffer	Additional size of video decoder buffer

virtual void H323Channel::OnMiscellaneousCommand ( const H245_MiscellaneousCommand_type & type )

virtual

Process a miscellaneous command on the logical channel. The default behaviour passes this on to the codec if not NULL.

Parameters

type	Command to process

virtual void H323Channel::OnMiscellaneousIndication ( const H245_MiscellaneousIndication_type & type )

virtual

Process a miscellaneous indication on the logical channel. The default behaviour passes this on to the codec if not NULL.

Parameters

type	Indication to process

virtual PBoolean H323Channel::OnReceivedAckPDU ( const H245_OpenLogicalChannelAck & pdu )

virtual

This is called after a request to create a channel occurs from the local machine via the H245LogicalChannelDict::Open() function, and the request has been acknowledged by the remote endpoint.

The default behaviour just returns true.

Parameters

pdu	Acknowledgement PDU

Reimplemented in H323DataChannel, H323_RealTimeChannel, and H323_T120Channel.

virtual PBoolean H323Channel::OnReceivedPDU	(	const H245_OpenLogicalChannel &	pdu,
		unsigned &	errorCode
	)

virtual

This is called after a request to create a channel occurs from the local machine via the H245LogicalChannelDict::Open() function, and the request has been acknowledged by the remote endpoint.

The default behaviour just returns true.

Parameters

pdu	Open PDU
errorCode	Error code on failure

Reimplemented in H323DataChannel, H323_RealTimeChannel, and H323_T120Channel.

virtual PBoolean H323Channel::OnSendingPDU ( H245_OpenLogicalChannel & openPDU ) const

virtual

Fill out the OpenLogicalChannel PDU for the particular channel type.

Parameters

openPDU Open PDU to send.

Reimplemented in H323DataChannel, H323_RealTimeChannel, and H323_T120Channel.

virtual void H323Channel::OnSendOpenAck	(	const H245_OpenLogicalChannel &	open,
		H245_OpenLogicalChannelAck &	ack
	)		const

virtual

This is called when request to create a channel is received from a remote machine and is about to be acknowledged.

The default behaviour does nothing.

Parameters

open	Open PDU
ack	Acknowledgement PDU

Reimplemented in H323DataChannel, H323_RealTimeChannel, and H323_T120Channel.

virtual PBoolean H323Channel::Open ( )

virtual

Open the channel. The default behaviour just calls connection.OnStartLogicalChannel() and if successful sets the opened member variable.

Reimplemented in H323UnidirectionalChannel.

virtual bool H323Channel::PreOpen ( )

virtual

PreOpen the channel. This occurs when we send an OLC, full open happens when the OLC comes back.

Default behaviour calls Open().

Reimplemented in H323UnidirectionalChannel.

virtual void H323Channel::PrintOn ( ostream & strm ) const

virtual

bool H323Channel::SetBandwidthUsed ( OpalBandwidth bandwidth )

Get the bandwidth used by the channel in 100's of bits/sec.

Parameters

bandwidth New bandwidth

virtual PBoolean H323Channel::SetInitialBandwidth ( )

pure virtual

Set the initial bandwidth for the channel. This calculates the initial bandwidth required by the channel and returns true if the connection can support this bandwidth.

The default behaviour gets the bandwidth requirement from the codec object created by the channel.

Implemented in H323UnidirectionalChannel.

virtual void H323Channel::SetMediaStream ( OpalMediaStreamPtr mediaStream )

virtual

Set the media stream associated with this logical channel. The default behaviour does nothing.

Reimplemented in H323UnidirectionalChannel.

void H323Channel::SetNumber ( const H323ChannelNumber & num )

inline

Set the number of the channel.

References number.

void H323Channel::SetReverseChannel ( const H323ChannelNumber & num )

inline

Set the number of the reverse channel (if present).

References reverseChannel.

virtual bool H323Channel::SetSessionID ( unsigned sessionID )

virtual

Set the session number of the channel. During OLC negotations teh master may change the session number being used for the logical channel.

Returns false if the session could not be renumbered.

Parameters

sessionID New session ID

Reimplemented in H323_RTPChannel.

virtual bool H323Channel::UpdateMediaFormat ( const OpalMediaFormat & mediaFormat )

virtual

Update media format options.

Reimplemented in H323UnidirectionalChannel.

Field Documentation

H323Capability* H323Channel::capability

protected

Referenced by GetCapability().

H323Connection& H323Channel::connection

protected

H323EndPoint& H323Channel::endpoint

protected

atomic<bool> H323Channel::m_terminating

protected

Referenced by IsOpen().

H323ChannelNumber H323Channel::number

protected

Referenced by GetNumber(), and SetNumber().

bool H323Channel::opened

protected

Referenced by IsOpen().

H323ChannelNumber H323Channel::reverseChannel

protected

Referenced by GetReverseChannel(), and SetReverseChannel().

The documentation for this class was generated from the following file:

channels.h

Public Member Functions

Protected Member Functions

Protected Attributes

Operations

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Field Documentation