dirac::ArithCodec< T > Class Template Reference

Abstract binary arithmetic coding class. More...

#include <arith_codec.h>

Inheritance diagram for dirac::ArithCodec< T >:

Collaboration diagram for dirac::ArithCodec< T >:

Public Member Functions
	ArithCodec (ByteIO *p_byteio, size_t number_of_contexts)
	Constructor for encoding. More...
virtual	~ArithCodec ()
	Destructor. More...
int	Compress (T &in_data)
	Compresses the input and returns the number of bits written. More...
void	Decompress (T &out_data, const int num_bytes)
	Decompresses the bitstream and writes into the output. More...
Public Member Functions inherited from dirac::ArithCodecBase
	ArithCodecBase (ByteIO *p_byteio, size_t number_of_contexts)
	Constructor. More...
virtual	~ArithCodecBase ()
	Destructor. More...

Protected Member Functions
virtual void	DoWorkCode (T &in_data)=0
	Does the work of actually coding the data. More...
virtual void	DoWorkDecode (T &out_data)=0
	virtual decode-only functions More...
Protected Member Functions inherited from dirac::ArithCodecBase
void	InitEncoder ()
	Initialises the Encoder. More...
void	EncodeSymbol (const bool symbol, const int context_num)
	encodes a symbol and writes to output More...
void	EncodeUInt (const unsigned int value, const int bin1, const int max_bin)
void	EncodeSInt (const int value, const int bin1, const int max_bin)
void	FlushEncoder ()
	flushes the output of the encoder. More...
int	ByteCount () const
void	InitDecoder (int num_bytes)
	Initialise the Decoder. More...
bool	DecodeSymbol (int context_num)
	Decodes a symbol given a context number. More...
unsigned int	DecodeUInt (const int bin1, const int max_bin)
int	DecodeSInt (const int bin1, const int max_bin)

Additional Inherited Members
Protected Attributes inherited from dirac::ArithCodecBase
std::vector< Context >	m_context_list
	List of contexts. More...

Detailed Description

template<class T>
class dirac::ArithCodec< T >

This is an abtract binary arithmetic encoding class, used as the base for concrete classes that encode motion vectors and subband residues.

Parameters

T	a container (most probably, or array) type

Constructor & Destructor Documentation

template<class T >

dirac::ArithCodec< T >::ArithCodec	(	ByteIO *	p_byteio,
		size_t	number_of_contexts
	)

Creates an ArithCodec object to decode input based on a set of parameters.

Parameters

p_byteio	input/output for encoded bits
number_of_contexts	the number of contexts used

template<class T>

virtual dirac::ArithCodec< T >::~ArithCodec ( )

inlinevirtual

Destructor is virtual as this class is abstract.

Member Function Documentation

template<class T>

int dirac::ArithCodec< T >::Compress

(

T &

in_data

)

Compress takes a type T object (a container or array) and compresses it using the abstract function DoWorkCode() which is overridden in subclasses. It returns the number of bits written.

Parameters

in_data

the input to be compressed. Non-const, since the compression may be lossy.

References dirac::ArithCodecBase::ByteCount(), dirac::ArithCodec< T >::DoWorkCode(), dirac::ArithCodecBase::FlushEncoder(), and dirac::ArithCodecBase::InitEncoder().

template<class T>

void dirac::ArithCodec< T >::Decompress	(	T &	out_data,
		const int	num_bytes
	)

Decompresses the bitstream, up to the number of bytes specified and writes into the output subclasses.

Parameters

out_data	the output into which the decompressed data is written.
num_bytes	the number of bytes to be read from the bitstream.

References dirac::ArithCodec< T >::DoWorkDecode(), and dirac::ArithCodecBase::InitDecoder().

template<class T>

virtual void dirac::ArithCodec< T >::DoWorkCode ( T &  in_data )

protectedpure virtual

Implemented in dirac::DCCodec, dirac::IntraDCBandCodec, dirac::VectorElementCodec, dirac::PredModeCodec, dirac::GenericBandCodec< ArithCodec< CoeffArray > >, and dirac::SplitModeCodec.

Referenced by dirac::ArithCodec< T >::Compress().

template<class T>

virtual void dirac::ArithCodec< T >::DoWorkDecode ( T &  out_data )

protectedpure virtual

Implemented in dirac::DCCodec, dirac::IntraDCBandCodec, dirac::VectorElementCodec, dirac::PredModeCodec, dirac::GenericBandCodec< ArithCodec< CoeffArray > >, and dirac::SplitModeCodec.

Referenced by dirac::ArithCodec< T >::Decompress().

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

• arith_codec.h