Dirac - A Video Codec

Created by the British Broadcasting Corporation.


Public Member Functions | Private Member Functions | Private Attributes
dirac::EntropyCorrector Class Reference

A class used for correcting estimates of entropy. More...

#include <common.h>

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List of all members.

Public Member Functions

 EntropyCorrector (int depth)
 Constructor.
float Factor (const int bandnum, const PictureParams &pp, const CompSort c) const
 Returns the correction factor.
void Update (int bandnum, const PictureParams &pp, CompSort c, int est_bits, int actual_bits)
 Update the correction factors.

Private Member Functions

void Init ()
 Initialises the correction factors.

Private Attributes

TwoDArray< float > m_Yfctrs
TwoDArray< float > m_Ufctrs
TwoDArray< float > m_Vfctrs

Detailed Description

A class used by the encoder for correcting estimates of entropy. Used for selecting quantisers in subband coefficient coding. Factors can be adjusted in the light of previous experience.


Constructor & Destructor Documentation

dirac::EntropyCorrector::EntropyCorrector ( int  depth)

Constructs arrays of correction factors of size.

Parameters:
depththe depth of the wavelet transform.

Member Function Documentation

float dirac::EntropyCorrector::Factor ( const int  bandnum,
const PictureParams pp,
const CompSort  c 
) const

Returns the correction factor for the band given also the type of picture and component.

void dirac::EntropyCorrector::Init ( )
private
void dirac::EntropyCorrector::Update ( int  bandnum,
const PictureParams pp,
CompSort  c,
int  est_bits,
int  actual_bits 
)

Update the factors for a given subband, component and picture type.

Parameters:
bandnumthe number of the subband to update
pppicture parameters
ccomponent type
est_bitsthe number of bits it was estimated would be used
actual_bitsthe number of bits that actually were used

Member Data Documentation

TwoDArray<float> dirac::EntropyCorrector::m_Ufctrs
private
TwoDArray<float> dirac::EntropyCorrector::m_Vfctrs
private
TwoDArray<float> dirac::EntropyCorrector::m_Yfctrs
private

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

© 2004 British Broadcasting Corporation. Dirac code licensed under the Mozilla Public License (MPL) Version 1.1.
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