OpalStreamedTranscoder Class Reference

#include <transcoders.h>

Inheritance diagram for OpalStreamedTranscoder:

List of all members.

Public Member Functions
Operations
virtual PINDEX	GetOptimalDataFrameSize (BOOL input) const
virtual BOOL	Convert (const RTP_DataFrame &input, RTP_DataFrame &output)
virtual int	ConvertOne (int sample) const=0
Protected Attributes
unsigned	inputBitsPerSample
unsigned	outputBitsPerSample
PINDEX	optimalSamples

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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.

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Constructor & Destructor Documentation

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

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
optimalSamples	Optimal number of samples for read

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

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
optimalSamples	Optimal number of samples for read

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Member Function Documentation

virtual PINDEX OpalStreamedTranscoder::GetOptimalDataFrameSize

(

BOOL

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.

virtual BOOL 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.

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_G711_uLaw_PCM, Opal_PCM_G711_uLaw, Opal_G711_ALaw_PCM, Opal_PCM_G711_ALaw, Opal_Linear16Mono_PCM, and Opal_PCM_Linear16Mono.

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Member Data Documentation

unsigned OpalStreamedTranscoder::inputBitsPerSample [protected]

unsigned OpalStreamedTranscoder::outputBitsPerSample [protected]

PINDEX OpalStreamedTranscoder::optimalSamples [protected]

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

• transcoders.h

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