Binary arithmetic encoder class. More...

#include <arithCoder.hpp>

Public Member Functions
	BinArithEncoder (int numContexts, OutputBitStream *out=nullptr)
	Create an arithmetic encoder with the specified number of contexts that sends output to the given bit stream. More...

	~BinArithEncoder ()
	Destroy an arithmetic encoder. More...

int	getNumContexts () const
	Get the number of contexts. More...

SPL_ArithCoder_ulong	getSymCount () const
	Get the number of symbols output so far. More...

SPL_ArithCoder_ulong	getBitCount () const
	Get the number of bits output so far. More...

void	setOutput (OutputBitStream *out)
	Set the bit stream to which encoded data should be written. More...

OutputBitStream *	getOutput () const
	Get the bit stream to which encoded data should be written. More...

void	setContextState (int contextId, ArithCoder::Freq oneFreq, ArithCoder::Freq totalFreq, ArithCoder::Freq maxFreq, bool adaptive)
	Set the symbol probabilities and adaptivity for the specified context. More...

void	getContextState (int contextId, ArithCoder::Freq &oneFreq, ArithCoder::Freq &totalFreq, ArithCoder::Freq &maxFreq, bool &adaptive)
	Get the symbol probabilities and adaptivity for the specified context. More...

int	start ()
	Start a code word. More...

int	encodeRegular (int contextId, int binVal)
	Encode the specified symbol in the given context. More...

int	encodeBypass (int binVal)
	Encode the specified symbol in bypass mode (i.e., using a fixed probability distribution with all symbols being equiprobable). More...

int	terminate ()
	Terminate the code word. More...

void	dump (std::ostream &out) const
	Dump the internal encoder state to the specified output stream for debugging purposes. More...

void	dumpModels (std::ostream &out) const
	Dump the internal encoder context state to the specified output stream for debugging purposes. More...

Static Public Member Functions
static void	setDebugLevel (int debugLevel)
	Set the debug level. More...

static void	setDebugStream (std::ostream &out)
	Set the stream to use for debugging output. More...

static std::ostream &	getDebugStream ()
	Get the stream used for debugging output. More...

Detailed Description

Binary arithmetic encoder class.

Constructor & Destructor Documentation

SPL::BinArithEncoder::BinArithEncoder	(	int	numContexts,
		OutputBitStream *	out = `nullptr`
	)

Create an arithmetic encoder with the specified number of contexts that sends output to the given bit stream.

Parameters

numContexts	The number of contexts.
out	The output bit stream.

This constructor creates an arithmetic encoder with the number of contexts being numContexts that sends output to the bit stream out.

SPL::BinArithEncoder::~BinArithEncoder ( )

Destroy an arithmetic encoder.

This destructor destroys an arithmetic encoder.

Member Function Documentation

void SPL::BinArithEncoder::dump ( std::ostream & out ) const

Dump the internal encoder state to the specified output stream for debugging purposes.

void SPL::BinArithEncoder::dumpModels ( std::ostream & out ) const

Dump the internal encoder context state to the specified output stream for debugging purposes.

int SPL::BinArithEncoder::encodeBypass ( int binVal )

Encode the specified symbol in bypass mode (i.e., using a fixed probability distribution with all symbols being equiprobable).

Parameters

binVal The symbol to be encoded.

This function encodes the symbol binVal in bypass mode (i.e., using a fixed probability distribution with all symbols being equiprobable). The symbol to be encoded must be either 0 or 1.

Returns: Upon success, zero is returned; otherwise, a nonzero value is returned.

int SPL::BinArithEncoder::encodeRegular	(	int	contextId,
		int	binVal
	)

Encode the specified symbol in the given context.

Parameters

contextId	The ID of the context to be used for encoding.
binVal	The symbol to be encoded.

This function encodes the symbol binVal using the context specified by contextId. The value of contextId must be from 0 to n - 1 (inclusive), where n is the number of contexts employed by the arithmetic encoder. The symbol to be encoded must be either 0 or 1.

Returns: Upon success, zero is returned; otherwise, a nonzero value is returned.

void SPL::BinArithEncoder::getContextState	(	int	contextId,
		ArithCoder::Freq &	oneFreq,
		ArithCoder::Freq &	totalFreq,
		ArithCoder::Freq &	maxFreq,
		bool &	adaptive
	)

Get the symbol probabilities and adaptivity for the specified context.

Parameters

	contextId	The ID of the context to query.
[out]	oneFreq	The frequency count for a one symbol.
[out]	totalFreq	The normalizing frequency count for all symbols.
[out]	maxFreq	The maximum normalizing frequency count.
[out]	adaptive	The adaptivity flag.

This function queries the state of the context with the context ID contextId, and sets the parameters oneFreq, totalFreq, maxFreq, and adaptive appropriately. The probability of a one symbol is given by oneFreq / totalFreq, while the probability of a zero symbol is given by 1 - oneFreq / totalFreq.

void SPL::BinArithEncoder::setContextState	(	int	contextId,
		ArithCoder::Freq	oneFreq,
		ArithCoder::Freq	totalFreq,
		ArithCoder::Freq	maxFreq,
		bool	adaptive
	)

Set the symbol probabilities and adaptivity for the specified context.

int SPL::BinArithEncoder::start ( )

Start a code word.

This function starts the encoding of a new code word. This function must be called before attempting to encode any symbols.

Returns: Upon success, zero is returned; otherwise, a nonzero value is returned.

int SPL::BinArithEncoder::terminate ( )

Terminate the code word.

This function terminates the encoding of the current arithmetic code word.

Returns: Upon success, zero is returned; otherwise, a nonzero value is returned.

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

arithCoder.hpp
arithCoder.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation