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/* ***** BEGIN LICENSE BLOCK *****
*
* $Id: quant_chooser.h,v 1.7 2008/05/27 01:29:54 asuraparaju Exp $ $Name: $
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
* the specific language governing rights and limitations under the License.
*
* The Original Code is BBC Research and Development code.
*
* The Initial Developer of the Original Code is the British Broadcasting
* Corporation.
* Portions created by the Initial Developer are Copyright (C) 2004.
* All Rights Reserved.
*
* Contributor(s): Thomas Davies (Original Author)
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License Version 2 (the "GPL"), or the GNU Lesser
* Public License Version 2.1 (the "LGPL"), in which case the provisions of
* the GPL or the LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the either
* the GPL or LGPL and not to allow others to use your version of this file
* under the MPL, indicate your decision by deleting the provisions above
* and replace them with the notice and other provisions required by the GPL
* or LGPL. If you do not delete the provisions above, a recipient may use
* your version of this file under the terms of any one of the MPL, the GPL
* or the LGPL.
* ***** END LICENSE BLOCK ***** */
#ifndef _QUANT_CHOOSER_H_
#define _QUANT_CHOOSER_H_
#include <libdirac_common/arrays.h>
#include <libdirac_common/wavelet_utils.h>
#include <libdirac_common/common.h>
namespace dirac
{
//! Choose a quantiser
/*!
This class chooses a quantiser or quantisers for a subband
*/
class QuantChooser
{
public:
//! Constructor
QuantChooser(const CoeffArray& pic_data , const float lambda);
//! Finds the best quantisers for the subband, returning the predicted number of bits needed
int GetBestQuant(Subband& node);
//! Sets the factor used for correcting the entropy calculation
void SetEntropyCorrection(const float ecfac)
{
m_entropy_correctionfactor = ecfac;
}
private:
//! Copy constructor is private and body-less. This class should not be copied.
QuantChooser(const QuantChooser& cpy);
//! Assignment = is private and body-less. This class should not be assigned.
QuantChooser& operator=(const QuantChooser& rhs);
//! Calculate errors and entropies for integral-bit quantisers
void IntegralErrorCalc(Subband& node , const int xratio , const int yratio);
//! Calculate errors and entropies for non-integral-bit quantisers
void NonIntegralErrorCalc(Subband& node, const int xratio, const int yratio);
//! Having got statistics, calculate the Lagrangian costs
void LagrangianCalc();
//! Select the best quantisation index on the basis of the Lagrangian calculations
void SelectBestQuant();
CoeffType BlockAbsMax(const Subband& node);
//! Set the skip flag for a codeblock
void SetSkip(CodeBlock& cblock , const int qidx);
private:
//! The perceptual weighting factor of the subband being tested
float m_subband_wt;
//! The smallest quantisation index being tested
int m_bottom_idx;
//! The largest quantisation index being tested
int m_top_idx;
//! The step we use in jumping through the list of quantisers
int m_index_step;
//! The index of the quantiser with the lowest cost
int m_min_idx;
//! A local reference to the data under consideration
const CoeffArray& m_coeff_data;
//! The lambda value to be used in the Lagrangian calculation
const float m_lambda;
//! A value for correcting the crude calculation of the entropy
float m_entropy_correctionfactor;
//! An array used to count the number of zeroes
OneDArray<int> m_count0;
//! The number of ones (equal to the number of coefficients)
int m_count1;
//! An array used to count the number of positive values
OneDArray<int> m_countPOS;
//! An array used to count the number of negative values
OneDArray<int> m_countNEG;
//! An array used to collate the sum of the perceptually-weighted errors
OneDArray<double> m_error_total;
//! An array used to collate the computed costs
OneDArray<CostType> m_costs;
};
} // namespace dirac
#endif
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