OpalLineMediaStream Class Reference

#include <lidep.h>

Inheritance diagram for OpalLineMediaStream:


Public Member Functions
Overrides of OpalMediaStream class
virtual PBoolean	Open ()
virtual PBoolean	Close ()
virtual PBoolean	ReadPacket (RTP_DataFrame &packet)
virtual PBoolean	WritePacket (RTP_DataFrame &packet)
virtual PBoolean	ReadData (BYTE *data, PINDEX size, PINDEX &length)
virtual PBoolean	WriteData (const BYTE *data, PINDEX length, PINDEX &written)
virtual PBoolean	SetDataSize (PINDEX dataSize)
virtual PBoolean	IsSynchronous () const
virtual PBoolean	RequiresPatchThread (OpalMediaStream *sinkStream) const
Member variable access
OpalLine &	GetLine ()
Protected Attributes
OpalLine &	line
bool	notUsingRTP
bool	useDeblocking
unsigned	missedCount
BYTE	lastSID [4]
bool	lastFrameWasSignal
unsigned	directLineNumber

Detailed Description

This class describes a media stream that transfers data to/from a Line Interface Device.

Constructor & Destructor Documentation

OpalLineMediaStream::OpalLineMediaStream	(	OpalLineConnection &	conn,
		const OpalMediaFormat &	mediaFormat,
		unsigned	sessionID,
		PBoolean	isSource,
		OpalLine &	line
	)

Construct a new media stream for Line Interface Devices.

Parameters:

mediaFormat	Media format for stream
sessionID	Session number for stream
isSource	Is a source stream
line	LID line to stream to/from

OpalLineMediaStream::OpalLineMediaStream	(	OpalLineConnection &	conn,
		const OpalMediaFormat &	mediaFormat,
		unsigned	sessionID,
		PBoolean	isSource,
		OpalLine &	line
	)

Construct a new media stream for Line Interface Devices.

Parameters:

mediaFormat	Media format for stream
sessionID	Session number for stream
isSource	Is a source stream
line	LID line to stream to/from

Member Function Documentation

virtual PBoolean OpalLineMediaStream::Open ( ) [virtual]

Open the media stream.

The default behaviour sets the OpalLineInterfaceDevice format and calls Resume() on the associated OpalMediaPatch thread.

Reimplemented from OpalMediaStream.

virtual PBoolean OpalLineMediaStream::Close ( ) [virtual]

Close the media stream.

The default does nothing.

Reimplemented from OpalMediaStream.

virtual PBoolean OpalLineMediaStream::ReadPacket ( RTP_DataFrame & packet ) [virtual]

Read an RTP frame of data from the source media stream. The default behaviour simply calls ReadData() on the data portion of the RTP_DataFrame and sets the frames timestamp and marker from the internal member variables of the media stream class.

Reimplemented from OpalMediaStream.

virtual PBoolean OpalLineMediaStream::WritePacket ( RTP_DataFrame & packet ) [virtual]

Write an RTP frame of data to the sink media stream. The default behaviour simply calls WriteData() on the data portion of the RTP_DataFrame and and sets the internal timestamp and marker from the member variables of the media stream class.

Reimplemented from OpalMediaStream.

virtual PBoolean OpalLineMediaStream::ReadData	(	BYTE *	data,
		PINDEX	size,
		PINDEX &	length
	)			`[virtual]`

Read raw media data from the source media stream. The default behaviour reads from the OpalLine object.

Parameters:

data	Data buffer to read to
size	Size of buffer
length	Length of data actually read

Reimplemented from OpalMediaStream.

virtual PBoolean OpalLineMediaStream::WriteData	(	const BYTE *	data,
		PINDEX	length,
		PINDEX &	written
	)			`[virtual]`

Write raw media data to the sink media stream. The default behaviour writes to the OpalLine object.

Parameters:

data	Data to write
length	Length of data to read.
written	Length of data actually written

Reimplemented from OpalMediaStream.

virtual PBoolean OpalLineMediaStream::SetDataSize ( PINDEX dataSize ) [virtual]

Set the data size in bytes that is expected to be used. Some media streams can make use of this information to perform optimisations.

The default behaviour does nothing.

Parameters:

dataSize

New data size

Reimplemented from OpalMediaStream.

virtual PBoolean OpalLineMediaStream::IsSynchronous ( ) const [virtual]

Indicate if the media stream is synchronous. Returns PTrue for LID streams.

Implements OpalMediaStream.

virtual PBoolean OpalLineMediaStream::RequiresPatchThread ( OpalMediaStream * sinkStream ) const [virtual]

Indicate if the media stream requires a OpalMediaPatch thread (active patch). This is called on the source stream and is passed the sink stream that the patch will initially be using. The function could conditionally require the patch thread to execute a thread reading and writing data, or prevent it from doing so as it can do so in hardware in some way, e.g. if both streams where on the same OpalLineInterfaceDevice.

The default behaviour simply returns true.

Parameters:

sinkStream

Sink stream for this source

Reimplemented from OpalMediaStream.

OpalLine& OpalLineMediaStream::GetLine ( ) [inline]

Get the line being used by this media stream.