Dirac - A Video Codec

Created by the British Broadcasting Corporation.


dirac::EntropyCorrector Class Reference

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

#include <common.h>

Collaboration diagram for dirac::EntropyCorrector:

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

◆ EntropyCorrector()

dirac::EntropyCorrector::EntropyCorrector ( int depth)

Constructs arrays of correction factors of size.

Parameters
depththe depth of the wavelet transform.

Member Function Documentation

◆ Factor()

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.

◆ Init()

void dirac::EntropyCorrector::Init ( )
private

◆ Update()

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

◆ m_Ufctrs

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

◆ m_Vfctrs

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

◆ m_Yfctrs

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.
HTML documentation generated by Dimitri van Heesch's excellent Doxygen tool.