A class specially for coding the DC subband of Intra frames. More...

#include <band_codec.h>

Inheritance diagram for dirac::IntraDCBandCodec:

Collaboration diagram for dirac::IntraDCBandCodec:

Public Member Functions
	IntraDCBandCodec (SubbandByteIO *subband_byteio, size_t number_of_contexts, const SubbandList &band_list)
	Constructor.
Public Member Functions inherited from dirac::GenericIntraDCBandCodec< ArithCodec< CoeffArray > >
	GenericIntraDCBandCodec (SubbandByteIO *subband_byteio, size_t number_of_contexts, const SubbandList &band_list)
	Constructor.
Public Member Functions inherited from dirac::GenericBandCodec< ArithCodec< CoeffArray > >
	GenericBandCodec (SubbandByteIO *subband_byteio, size_t number_of_contexts, const SubbandList &band_list, int band_num, const bool is_intra)
	Constructor.
Public Member Functions inherited from dirac::ArithCodec< CoeffArray >
	ArithCodec (ByteIO *p_byteio, size_t number_of_contexts)
	Constructor for encoding.
virtual	~ArithCodec ()
	Destructor.
int	Compress (CoeffArray &in_data)
	Compresses the input and returns the number of bits written.
void	Decompress (CoeffArray &out_data, const int num_bytes)
	Decompresses the bitstream and writes into the output.
Public Member Functions inherited from dirac::ArithCodecBase
	ArithCodecBase (ByteIO *p_byteio, size_t number_of_contexts)
	Constructor.
virtual	~ArithCodecBase ()
	Destructor.

Private Member Functions
void	DoWorkCode (CoeffArray &in_data)
	Initialize extra data required for error-feedback DC quantization.
void	DoWorkDecode (CoeffArray &out_data)
	Ditto.
void	CodeCoeff (CoeffArray &in_data, const int xpos, const int ypos)
	Encode a single coefficient using error-feedback DC quantization.
void	DecodeCoeff (CoeffArray &out_data, const int xpos, const int ypos)
	Decode a single coefficient using error-feedback DC quantization.
	IntraDCBandCodec (const IntraDCBandCodec &cpy)
	Private, bodyless copy constructor: class should not be copied.
IntraDCBandCodec &	operator= (const IntraDCBandCodec &rhs)
	Private, bodyless copy operator=: class should not be assigned.

Private Attributes
CoeffArray	m_dc_pred_res

Additional Inherited Members
Protected Member Functions inherited from dirac::GenericIntraDCBandCodec< ArithCodec< CoeffArray > >
void	ClearBlock (const CodeBlock &code_block, CoeffArray &coeff_data)
	When coding a skipped block, propegate the predicted values for future non skipped blocks.
CoeffType	GetPrediction (const CoeffArray &data, const int xpos, const int ypos) const
	Prediction of a DC value from its previously coded neighbours.
void	DecodeCoeffBlock (const CodeBlock &code_block, CoeffArray &out_data)
	Decode codeblock of coefficients and perform DC prediction.
Protected Member Functions inherited from dirac::GenericBandCodec< ArithCodec< CoeffArray > >
void	CodeVal (CoeffArray &in_data, const int xpos, const int ypos, const CoeffType val)
	Code an individual quantised value and perform inverse-quantisation.
void	DecodeVal (CoeffArray &out_data, const int xpos, const int ypos)
	Decode an individual quantised value and perform inverse-quantisation.
void	CodeQuantIndexOffset (const int offset)
	Encode the offset for a code block quantiser.
int	DecodeQuantIndexOffset ()
	Decode the offset for a code block quantiser.
void	SetToVal (const CodeBlock &code_block, CoeffArray &coeff_data, const CoeffType val)
	Set a code block area to a given value.
virtual void	CodeCoeffBlock (const CodeBlock &code_block, CoeffArray &in_data)
int	ChooseFollowContext (const int bin_number) const
	A function for choosing the context for "follow bits".
int	ChooseInfoContext () const
	A function for choosing the context for "information bits".
int	ChooseSignContext (const CoeffArray &data, const int xpos, const int ypos) const
	A function for choosing the context for sign bits.

Detailed Description

A class specially for coding the DC subband of Intra frames, using intra-band prediction of coefficients. It uses the abstract ArithCodec class

Constructor & Destructor Documentation

dirac::IntraDCBandCodec::IntraDCBandCodec	(	SubbandByteIO *	subband_byteio,
		size_t	number_of_contexts,
		const SubbandList &	band_list
	)

inline

Creates a IntraDCBandCodec object to encode subband data, based on parameters

Parameters:

subband_byteio	input/output for the encoded bits
number_of_contexts	the number of contexts used in the encoding process
band_list	the set of all the subbands