Dirac - A Video Codec

Created by the British Broadcasting Corporation.


quant_chooser.h
Go to the documentation of this file.
1/* ***** BEGIN LICENSE BLOCK *****
2*
3* $Id: quant_chooser.h,v 1.7 2008/05/27 01:29:54 asuraparaju Exp $ $Name: Dirac_1_0_2 $
4*
5* Version: MPL 1.1/GPL 2.0/LGPL 2.1
6*
7* The contents of this file are subject to the Mozilla Public License
8* Version 1.1 (the "License"); you may not use this file except in compliance
9* with the License. You may obtain a copy of the License at
10* http://www.mozilla.org/MPL/
11*
12* Software distributed under the License is distributed on an "AS IS" basis,
13* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
14* the specific language governing rights and limitations under the License.
15*
16* The Original Code is BBC Research and Development code.
17*
18* The Initial Developer of the Original Code is the British Broadcasting
19* Corporation.
20* Portions created by the Initial Developer are Copyright (C) 2004.
21* All Rights Reserved.
22*
23* Contributor(s): Thomas Davies (Original Author)
24*
25* Alternatively, the contents of this file may be used under the terms of
26* the GNU General Public License Version 2 (the "GPL"), or the GNU Lesser
27* Public License Version 2.1 (the "LGPL"), in which case the provisions of
28* the GPL or the LGPL are applicable instead of those above. If you wish to
29* allow use of your version of this file only under the terms of the either
30* the GPL or LGPL and not to allow others to use your version of this file
31* under the MPL, indicate your decision by deleting the provisions above
32* and replace them with the notice and other provisions required by the GPL
33* or LGPL. If you do not delete the provisions above, a recipient may use
34* your version of this file under the terms of any one of the MPL, the GPL
35* or the LGPL.
36* ***** END LICENSE BLOCK ***** */
37
38
39#ifndef _QUANT_CHOOSER_H_
40#define _QUANT_CHOOSER_H_
41
45
46namespace dirac
47{
49
53 {
54 public:
55
57 QuantChooser( const CoeffArray& pic_data , const float lambda );
58
60 int GetBestQuant( Subband& node );
61
63 void SetEntropyCorrection( const float ecfac ){ m_entropy_correctionfactor = ecfac; }
64 private:
67
70
72 void IntegralErrorCalc( Subband& node , const int xratio , const int yratio );
73
75 void NonIntegralErrorCalc( Subband& node, const int xratio, const int yratio );
76
79
82
84
86 void SetSkip( CodeBlock& cblock , const int qidx);
87
88 private:
91
98
101
104
106 const float m_lambda;
107
110
123
124 };
125
126} // namespace dirac
127
128
129
130#endif
Definition of class SequenceHeaderByteIO.
Definition accessunit_byteio.h:52
int CoeffType
Type of wavelet coefficient data (should be larger than ValueType)
Definition common.h:74
A template class for one-dimensional arrays.
Definition arrays.h:90
Class for encapsulating metadata concerning a block of coefficients in a subband.
Definition wavelet_utils.h:60
Class encapsulating all the metadata relating to a wavelet subband.
Definition wavelet_utils.h:140
A class for wavelet coefficient data.
Definition wavelet_utils.h:623
QuantChooser(const QuantChooser &cpy)
Copy constructor is private and body-less. This class should not be copied.
const float m_lambda
The lambda value to be used in the Lagrangian calculation.
Definition quant_chooser.h:106
void IntegralErrorCalc(Subband &node, const int xratio, const int yratio)
Calculate errors and entropies for integral-bit quantisers.
int m_top_idx
The largest quantisation index being tested.
Definition quant_chooser.h:95
void NonIntegralErrorCalc(Subband &node, const int xratio, const int yratio)
Calculate errors and entropies for non-integral-bit quantisers.
void SetEntropyCorrection(const float ecfac)
Sets the factor used for correcting the entropy calculation.
Definition quant_chooser.h:63
QuantChooser & operator=(const QuantChooser &rhs)
Assignment = is private and body-less. This class should not be assigned.
float m_entropy_correctionfactor
A value for correcting the crude calculation of the entropy.
Definition quant_chooser.h:109
int m_count1
The number of ones (equal to the number of coefficients)
Definition quant_chooser.h:114
int m_bottom_idx
The smallest quantisation index being tested.
Definition quant_chooser.h:93
float m_subband_wt
The perceptual weighting factor of the subband being tested.
Definition quant_chooser.h:90
int GetBestQuant(Subband &node)
Finds the best quantisers for the subband, returning the predicted number of bits needed.
void LagrangianCalc()
Having got statistics, calculate the Lagrangian costs.
OneDArray< double > m_error_total
An array used to collate the sum of the perceptually-weighted errors.
Definition quant_chooser.h:120
OneDArray< int > m_count0
An array used to count the number of zeroes.
Definition quant_chooser.h:112
QuantChooser(const CoeffArray &pic_data, const float lambda)
Constructor.
OneDArray< CostType > m_costs
An array used to collate the computed costs.
Definition quant_chooser.h:122
OneDArray< int > m_countNEG
An array used to count the number of negative values.
Definition quant_chooser.h:118
int m_min_idx
The index of the quantiser with the lowest cost.
Definition quant_chooser.h:100
void SetSkip(CodeBlock &cblock, const int qidx)
Set the skip flag for a codeblock.
const CoeffArray & m_coeff_data
A local reference to the data under consideration.
Definition quant_chooser.h:103
void SelectBestQuant()
Select the best quantisation index on the basis of the Lagrangian calculations.
int m_index_step
The step we use in jumping through the list of quantisers.
Definition quant_chooser.h:97
OneDArray< int > m_countPOS
An array used to count the number of positive values.
Definition quant_chooser.h:116
CoeffType BlockAbsMax(const Subband &node)

© 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.