OpalStreamedTranscoder Class Reference

#include <transcoders.h>

Inheritance diagram for OpalStreamedTranscoder:

Collaboration diagram for OpalStreamedTranscoder:

Public Member Functions
Construction
	OpalStreamedTranscoder (const OpalMediaFormat &inputMediaFormat, const OpalMediaFormat &outputMediaFormat, unsigned inputBits, unsigned outputBits)
Operations
virtual PINDEX	GetOptimalDataFrameSize (PBoolean input) const
virtual PBoolean	Convert (const RTP_DataFrame &input, RTP_DataFrame &output)
virtual int	ConvertOne (int sample) const =0
Public Member Functions inherited from OpalTranscoder
	OpalTranscoder (const OpalMediaFormat &inputMediaFormat, const OpalMediaFormat &outputMediaFormat)
virtual bool	UpdateMediaFormats (const OpalMediaFormat &inputMediaFormat, const OpalMediaFormat &outputMediaFormat)
virtual PBoolean	ExecuteCommand (const OpalMediaCommand &command)
virtual PBoolean	ConvertFrames (const RTP_DataFrame &input, RTP_DataFrameList &output)
PINDEX	GetMaxOutputSize () const
void	SetMaxOutputSize (PINDEX size)
void	SetCommandNotifier (const PNotifier &notifier)
const PNotifier &	GetCommandNotifier () const
void	NotifyCommand (const OpalMediaCommand &command) const
	Notify command notifier of command. More...
unsigned	GetSessionID () const
	Get session ID for the transcoder (from OpalMediaStream) More...
void	SetSessionID (unsigned id)
	Set session ID for the transcoder (from OpalMediaStream) More...
virtual void	SetInstanceID (const BYTE *instance, unsigned instanceLen)
RTP_DataFrame::PayloadTypes	GetPayloadType (PBoolean input) const
virtual bool	AcceptComfortNoise () const
virtual bool	AcceptEmptyPayload () const
virtual bool	AcceptOtherPayloads () const
virtual void	GetStatistics (OpalMediaStatistics &statistics) const
void	CopyTimestamp (RTP_DataFrame &dst, const RTP_DataFrame &src, bool inToOut) const
Public Member Functions inherited from OpalMediaFormatPair
	OpalMediaFormatPair (const OpalMediaFormat &inputMediaFormat, const OpalMediaFormat &outputMediaFormat)
void	PrintOn (ostream &strm) const
virtual Comparison	Compare (const PObject &obj) const
const OpalMediaFormat &	GetInputFormat () const
const OpalMediaFormat &	GetOutputFormat () const

Protected Attributes
unsigned	inputBitsPerSample
unsigned	outputBitsPerSample
Protected Attributes inherited from OpalTranscoder
PINDEX	maxOutputSize
PNotifier	commandNotifier
PMutex	updateMutex
unsigned	m_sessionID
bool	outputIsRTP
bool	inputIsRTP
bool	acceptEmptyPayload
bool	acceptOtherPayloads
unsigned	m_inClockRate
unsigned	m_outClockRate
RTP_DataFrame::PayloadTypes	m_lastPayloadType
unsigned	m_consecutivePayloadTypeMismatches
Protected Attributes inherited from OpalMediaFormatPair
OpalMediaFormat	inputMediaFormat
OpalMediaFormat	outputMediaFormat

Additional Inherited Members
Static Public Member Functions inherited from OpalTranscoder
static OpalTranscoder *	Create (const OpalMediaFormat &srcFormat, const OpalMediaFormat &dstFormat, const BYTE *instance=NULL, unsigned instanceLen=0)
static bool	SelectFormats (const OpalMediaType &mediaType, const OpalMediaFormatList &srcFormats, const OpalMediaFormatList &dstFormats, const OpalMediaFormatList &allFormats, OpalMediaFormat &srcFormat, OpalMediaFormat &dstFormat)
static bool	FindIntermediateFormat (const OpalMediaFormat &srcFormat, const OpalMediaFormat &dstFormat, OpalMediaFormat &intermediateFormat)
static OpalMediaFormatList	GetDestinationFormats (const OpalMediaFormat &srcFormat)
static OpalMediaFormatList	GetSourceFormats (const OpalMediaFormat &dstFormat)
static OpalMediaFormatList	GetPossibleFormats (const OpalMediaFormatList &formats)

Detailed Description

This class defines a transcoder implementation class where the encode/decode is streamed. That is each input n bit PCM sample is encoded to m bits of encoded data, eg G.711 etc.

An application may create a descendent off this class and override functions as required for descibing a specific transcoder.

Constructor & Destructor Documentation

OpalStreamedTranscoder::OpalStreamedTranscoder	(	const OpalMediaFormat &	inputMediaFormat,
		const OpalMediaFormat &	outputMediaFormat,
		unsigned	inputBits,
		unsigned	outputBits
	)

Create a new streamed transcoder implementation.

Parameters

inputMediaFormat	Input media format
outputMediaFormat	Output media format
inputBits	Bits per sample in input data
outputBits	Bits per sample in output data

Member Function Documentation

virtual PBoolean OpalStreamedTranscoder::Convert ( const RTP_DataFrame &  input, RTP_DataFrame &  output  )

virtual

Convert the data from one format to another. This function takes the input data as a RTP_DataFrame and converts it to its output format, placing it into the RTP_DataFrame provided.

Returns false if the conversion fails.

Parameters

input	Input data
output	Output data

Implements OpalTranscoder.

Reimplemented in Opal_G711_PCM.

virtual int OpalStreamedTranscoder::ConvertOne ( int  sample ) const

pure virtual

Convert one sample from one format to another. This function takes the input data as a single sample value and converts it to its output format.

Returns converted value.

Implemented in Opal_PCM_Linear16Mono, Opal_Linear16Mono_PCM, OpalPluginStreamedAudioTranscoder, Opal_PCM_G711_ALaw, Opal_G711_ALaw_PCM, Opal_PCM_G711_uLaw, and Opal_G711_uLaw_PCM.

virtual PINDEX OpalStreamedTranscoder::GetOptimalDataFrameSize ( PBoolean  input ) const

virtual

Get the optimal size for data frames to be converted. This function returns the size of frames that will be most efficient in conversion. A RTP_DataFrame will attempt to provide or use data in multiples of this size. Note that it may not do so, so the transcoder must be able to handle any sized packets.

Parameters

input

Flag for input or output data size

Implements OpalTranscoder.

Field Documentation

unsigned OpalStreamedTranscoder::inputBitsPerSample

protected

unsigned OpalStreamedTranscoder::outputBitsPerSample

protected

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

• transcoders.h