Statistical context for ArithmeticEncoder. More...

#include <ArithmeticEncoder.h>

Inheritance diagram for utl::ArithContext:

Public Member Functions
	ArithContext (uint_t numSymbols, uint_t inc, uint_t incLimit)
	Constructor. More...

virtual void	copy (const Object &rhs)
	Copy another ArithContext. More...

uint_t	freq (uint_t symbol) const
	Get the frequency count for the given symbol. More...

void	interval (uint_t low, uint_t high, uint_t symbol) const
	Return the total frequency of all symbols before the given symbol.

uint_t	numSymbols () const
	Return the number of symbols. More...

void	set (uint_t numSymbols, uint_t inc, uint_t incLimit)
	Set a new configuration. More...

uint_t	symbol (uint_t target)
	Return the symbol whose cumulative frequency count is the least that exceeds the given target.

uint_t	totFreq () const
	Return the total frequency of all symbols. More...

void	update (uint_t symbol)
	Add inc to the frequency count for the given symbol. More...

Public Member Functions inherited from utl::Object
void	clear ()
	Revert to initial state. More...

virtual int	compare (const Object &rhs) const
	Compare with another object. More...

virtual void	vclone (const Object &rhs)
	Make an exact copy of another instance. More...

virtual void	steal (Object &rhs)
	"Steal" the internal representation from another instance. More...

virtual void	dump (Stream &os, uint_t level=uint_t_max) const
	Dump a human-readable representation of self to the given output stream. More...

void	dumpWithClassName (Stream &os, uint_t indent=4, uint_t level=uint_t_max) const
	Front-end for dump() that prints the object's class name. More...

virtual const Object &	getKey () const
	Get the key for this object. More...

bool	hasKey () const
	Determine whether or not the object has a key. More...

virtual const Object &	getProxiedObject () const
	Get the proxied object (= self if none). More...

virtual Object &	getProxiedObject ()
	Get the proxied object (= self if none). More...

virtual size_t	hash (size_t size) const
	Get the hash code for the object. More...

bool	_isA (const RunTimeClass *runTimeClass) const
	Determine whether self's class is a descendent of the given class. More...

virtual String	toString () const
	Return a string representation of self. More...

	operator String () const
	Conversion to String. More...

size_t	allocatedSize () const
	Get the total allocated size of this object. More...

virtual size_t	innerAllocatedSize () const
	Get the "inner" allocated size. More...

virtual void	addOwnedIt (const class FwdIt *it) const
	Notify self that it owns the given iterator. More...

virtual void	removeOwnedIt (const class FwdIt *it) const
	Notify self that the given owned iterator has been destroyed. More...

bool	operator< (const Object &rhs) const
	Less-than operator. More...

bool	operator<= (const Object &rhs) const
	Less-than-or-equal-to operator. More...

bool	operator> (const Object &rhs) const
	Greater-than operator. More...

bool	operator>= (const Object &rhs) const
	Greater-than-or-equal-to operator. More...

bool	operator== (const Object &rhs) const
	Equal-to operator. More...

bool	operator!= (const Object &rhs) const
	Unequal-to operator. More...

void	serializeIn (Stream &is, uint_t mode=ser_default)
	Serialize from an input stream. More...

void	serializeOut (Stream &os, uint_t mode=ser_default) const
	Serialize to an output stream. More...

virtual void	serialize (Stream &stream, uint_t io, uint_t mode=ser_default)
	Serialize to or from a stream. More...

void	serializeOutBoxed (Stream &os, uint_t mode=ser_default) const
	Serialize a boxed object to an output stream. More...

Additional Inherited Members
Static Public Member Functions inherited from utl::Object
static Object *	serializeInNullable (Stream &is, uint_t mode=ser_default)
	Serialize a nullptr-able object from an input stream. More...

static void	serializeOutNullable (const Object *object, Stream &os, uint_t mode=ser_default)
	Serialize a nullptr-able object to an output stream. More...

static void	serializeNullable (Object *&object, Stream &stream, uint_t io, uint_t mode=ser_default)
	Serialize a nullptr-able object to or from a stream. More...

static Object *	serializeInBoxed (Stream &is, uint_t mode=ser_default)
	Serialize a boxed object from an input stream. More...

static void	serializeBoxed (Object *&object, Stream &stream, uint_t io, uint_t mode=ser_default)
	Serialize a boxed object to or from a stream. More...

Detailed Description

Statistical context for ArithmeticEncoder.

freq(), interval() and update() are all O(log n), thanks to the use of a Fenwick tree. Thanks go to Alistair Moffat who clued me into this elegant technique.

See Alistair's home page at: http://people.eng.unimelb.edu.au/ammoffat/

Author: Adam McKee

Definition at line 30 of file ArithmeticEncoder.h.

Constructor & Destructor Documentation

◆ ArithContext()

utl::ArithContext::ArithContext	(	uint_t	numSymbols,
		uint_t	inc,
		uint_t	incLimit
	)

inline

Constructor.

Parameters

numSymbols	alphabet size
inc	symbol frequency increment
incLimit	halve frequency counts when totFreq() exceeds incLimit

Definition at line 42 of file ArithmeticEncoder.h.

References utl::copy().

Member Function Documentation

◆ copy()

virtual void utl::ArithContext::copy ( const Object & rhs )

virtual

Copy another ArithContext.

Reimplemented from utl::Object.

◆ freq()

uint_t utl::ArithContext::freq ( uint_t symbol ) const

inline

Get the frequency count for the given symbol.

Definition at line 53 of file ArithmeticEncoder.h.

◆ numSymbols()

uint_t utl::ArithContext::numSymbols ( ) const

inline

Return the number of symbols.

Definition at line 68 of file ArithmeticEncoder.h.

◆ set()

void utl::ArithContext::set	(	uint_t	numSymbols,
		uint_t	inc,
		uint_t	incLimit
	)

Set a new configuration.

Parameters

numSymbols	number of distinct symbols
inc	symbol frequency increment
incLimit	halve frequency counts when totFreq() exceeds incLimit

◆ totFreq()

uint_t utl::ArithContext::totFreq ( ) const

inline

Return the total frequency of all symbols.

Definition at line 90 of file ArithmeticEncoder.h.

References utl::deInit(), and utl::init().

Referenced by utl::ArithmeticEncoder::decode(), and utl::ArithmeticEncoder::encode().

◆ update()

void utl::ArithContext::update ( uint_t symbol )

Add inc to the frequency count for the given symbol.

If totFreq() exceeds incLimit, all frequency counts are halved.

Referenced by utl::ArithmeticEncoder::decode(), and utl::ArithmeticEncoder::encode().

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

ArithmeticEncoder.h

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ArithContext()

Member Function Documentation

◆ copy()

◆ freq()

◆ numSymbols()

◆ set()

◆ totFreq()

◆ update()