dirac::ArithCodec< T >::Context Class Reference

A class for binary contexts. More...

#include <arith_codec.h>

List of all members.

Public Member Functions
	Context ()
	Default Constructor.
	Context (int cnt0, int cnt1)
	Constructor.
	Context (const Context &cpy)
	Copy constructor.
Context &	operator= (const Context &rhs)
	Assignment=.
	~Context ()
	Destructor.
void	SetCounts (int cnt0, int cnt1)
	Sets the counts according to the input.
code_t	GetCount0 () const
	Returns the count of zeroes.
code_t	GetCount1 () const
	Returns the count of ones.
void	IncrCount (bool symbol, int amnt)
	Increment the count.
void	HalveCounts ()
	Divide the counts by 2, making sure neither ends up 0.
code_t	Weight () const
	Return the m_m_weight, equal to the count of 0 plus the count of 1.
const Triple &	GetTriple (const bool symbol) const
	Return the triple associated with Symbol.
bool	GetSymbol (const code_t num, Triple &trip_val) const
	Given a number, return the corresponding symbol and triple.

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Detailed Description

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

A class for binary contexts.

A class for binary contexts. Stores probabilities for 0 and 1 in terms of counts of numbers of occurrences, and also as Triples partitioning the interval [0,1) into two parts [0,p) and [p,1).

Definition at line 202 of file arith_codec.h.

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Constructor & Destructor Documentation

template<class T> dirac::ArithCodec< T >::Context::Context (   )  [inline]

Default Constructor. Default constructor initialises counts to 1 each of 0 and 1. Definition at line 209 of file arith_codec.h. References dirac::ArithCodec< T >::Context::SetCounts().

template<class T> dirac::ArithCodec< T >::Context::Context (  int  cnt0, int  cnt1 )  [inline]

Constructor. Constructor initialises the counts to those set. Definition at line 218 of file arith_codec.h. References dirac::ArithCodec< T >::Context::SetCounts().

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Member Function Documentation

template<class T> bool dirac::ArithCodec< T >::Context::GetSymbol (  const code_t  num, Triple &  trip_val )  const [inline]

Given a number, return the corresponding symbol and triple. Given a number, which should be in the range [0,m_weight) return the corresponding symbol. The range [0,m_weight) is partitioned into portions [0,count0), [count0,m_weight) corresponding to 0 and 1. Definition at line 302 of file arith_codec.h. References dirac::ArithCodec< T >::ArithCodec(), dirac::ArithCodec< T >::ChooseContext(), dirac::ArithCodec< T >::DecodeSymbol(), dirac::ArithCodec< T >::DoWorkCode(), dirac::ArithCodec< T >::DoWorkDecode(), dirac::ArithCodec< T >::EncodeSymbol(), dirac::ArithCodec< T >::EncodeTriple(), dirac::ArithCodec< T >::FlushDecoder(), dirac::ArithCodec< T >::FlushEncoder(), dirac::ArithCodec< T >::InitContexts(), dirac::ArithCodec< T >::InitDecoder(), dirac::ArithCodec< T >::InitEncoder(), dirac::ArithCodec< T >::Context::operator=(), dirac::ArithCodec< T >::RemFromStream(), dirac::ArithCodec< T >::ResetAll(), dirac::ArithCodec< T >::Resize(), dirac::ArithCodec< T >::SetCurrentCount(), dirac::ArithCodec< T >::Triple::Start(), dirac::ArithCodec< T >::Triple::Stop(), dirac::ArithCodec< T >::Update(), and dirac::ArithCodec< T >::Triple::Weight().

template<class T> void dirac::ArithCodec< T >::Context::IncrCount (  bool  symbol, int  amnt )  [inline]

Increment the count. Increment the count of Symbol by amnt. Parameters: symbol  the symbol whose count is to be incremented (false=0, true=1) amnt  the amount to increment by Definition at line 268 of file arith_codec.h.

template<class T> void dirac::ArithCodec< T >::Context::SetCounts (  int  cnt0, int  cnt1 )  [inline]

Sets the counts according to the input. Sets the counts, and then the triples to reflect the counts. Definition at line 248 of file arith_codec.h. Referenced by dirac::ArithCodec< T >::Context::Context().

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

• C:/guliverkli/src/filters/parser/diracsplitter/libdirac/libdirac_common/arith_codec.h

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