# Dirac - A Video Codec

Created by the British Broadcasting Corporation.

# band_codec.h

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    00001 /* ***** BEGIN LICENSE BLOCK *****
    00002 *
    00003 * $Id: band_codec.h,v 1.36 2009/01/21 05:18:09 asuraparaju Exp $ $Name: Dirac_1_0_2 $
    00004 *
    00005 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
    00006 *
    00007 * The contents of this file are subject to the Mozilla Public License
    00008 * Version 1.1 (the "License"); you may not use this file except in compliance
    00009 * with the License. You may obtain a copy of the License at
    00010 * http://www.mozilla.org/MPL/
    00011 *
    00012 * Software distributed under the License is distributed on an "AS IS" basis,
    00013 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
    00014 * the specific language governing rights and limitations under the License.
    00015 *
    00016 * The Original Code is BBC Research and Development code.
    00017 *
    00018 * The Initial Developer of the Original Code is the British Broadcasting
    00019 * Corporation.
    00020 * Portions created by the Initial Developer are Copyright (C) 2004.
    00021 * All Rights Reserved.
    00022 *
    00023 * Contributor(s): Thomas Davies (Original Author),
    00024 *                 Scott R Ladd,
    00025 *                 Steve Bearcroft
    00026 *                 Andrew Kennedy
    00027 *
    00028 * Alternatively, the contents of this file may be used under the terms of
    00029 * the GNU General Public License Version 2 (the "GPL"), or the GNU Lesser
    00030 * Public License Version 2.1 (the "LGPL"), in which case the provisions of
    00031 * the GPL or the LGPL are applicable instead of those above. If you wish to
    00032 * allow use of your version of this file only under the terms of the either
    00033 * the GPL or LGPL and not to allow others to use your version of this file
    00034 * under the MPL, indicate your decision by deleting the provisions above
    00035 * and replace them with the notice and other provisions required by the GPL
    00036 * or LGPL. If you do not delete the provisions above, a recipient may use
    00037 * your version of this file under the terms of any one of the MPL, the GPL
    00038 * or the LGPL.
    00039 * ***** END LICENSE BLOCK ***** */
    00040
    00041 #ifndef _BAND_CODEC_H_
    00042 #define _BAND_CODEC_H_
    00043
    00044 #include <libdirac_common/arith_codec.h>
    00045 #include <libdirac_common/wavelet_utils.h>
    00046
    00047
    00048 namespace dirac
    00049 {
    00050
    00051    class SubbandByteIO;
    00052
    00053     //Subclasses the arithmetic codec to produce a coding/decoding tool for subbands
    00054
    00055
    00057     template<typename EntropyCodec>
    00058     class GenericBandCodec: public EntropyCodec
    00059     {
    00060     public:
    00061
    00063
    00071         GenericBandCodec(SubbandByteIO* subband_byteio,
    00072                   size_t number_of_contexts,
    00073                   const SubbandList& band_list,
    00074                   int band_num,
    00075                   const bool is_intra);
    00076
    00077     protected:
    00079         inline void CodeVal( CoeffArray& in_data , const int xpos , const int ypos , const CoeffType val);
    00080
    00082         inline void DecodeVal(CoeffArray& out_data , const int xpos , const int ypos );
    00083
    00085         void CodeQuantIndexOffset( const int offset );
    00086
    00088         int DecodeQuantIndexOffset();
    00089
    00091         inline void SetToVal( const CodeBlock& code_block , CoeffArray& coeff_data , const CoeffType val);
    00092
    00094         virtual void ClearBlock( const CodeBlock& code_block , CoeffArray& coeff_data);
    00095
    00096     protected:
    00097         //functions
    00098         // Overridden from the base class
    00099         virtual void DoWorkCode(CoeffArray& in_data);
    00100         // Ditto
    00101         virtual void DoWorkDecode(CoeffArray& out_data);
    00102
    00103         virtual void CodeCoeffBlock(const CodeBlock& code_block , CoeffArray& in_data);
    00104         virtual void DecodeCoeffBlock(const CodeBlock& code_block , CoeffArray& out_data);
    00105
    00106         virtual void CodeCoeff(CoeffArray& in_data, const int xpos, const int ypos);
    00107
    00108         virtual void DecodeCoeff(CoeffArray& in_data, const int xpos, const int ypos);
    00110         inline int ChooseFollowContext( const int bin_number ) const;
    00111
    00113         inline int ChooseInfoContext() const;
    00114
    00116         inline int ChooseSignContext(const CoeffArray& data , const int xpos , const int ypos ) const;
    00117
    00118     private:
    00120         GenericBandCodec(const GenericBandCodec& cpy);
    00122         GenericBandCodec& operator=(const GenericBandCodec& rhs);
    00123
    00124     protected:
    00125
    00127         bool m_is_intra;
    00128
    00130         int m_bnum;
    00131
    00133         const Subband m_node;
    00134
    00136         int m_last_qf_idx;
    00137
    00139         int m_qf;
    00140
    00142         CoeffType m_offset;
    00143
    00145         bool m_nhood_nonzero;
    00146
    00148         Subband m_pnode;
    00149
    00151         int m_pxpos, m_pypos;
    00152
    00154         bool m_parent_notzero;
    00155
    00156     };
    00157
    00159
    00162     typedef GenericBandCodec<ArithCodec<CoeffArray> > BandCodec;
    00163     typedef BandCodec LFBandCodec;
    00164
    00166     //Finally,special class incorporating prediction for the DC band of intra frames//
    00168
    00170     template<typename EntropyCodec>
    00171     class GenericIntraDCBandCodec : public GenericBandCodec<EntropyCodec>
    00172     {
    00173     public:
    00175
    00181         GenericIntraDCBandCodec(SubbandByteIO* subband_byteio,
    00182                          size_t number_of_contexts,
    00183                          const SubbandList& band_list)
    00184           : GenericBandCodec<EntropyCodec>(subband_byteio,number_of_contexts,
    00185                                            band_list, band_list.Length(),
    00186                                            true){}
    00187
    00188     protected:
    00190         void ClearBlock( const CodeBlock& code_block , CoeffArray& coeff_data);
    00191
    00193         CoeffType GetPrediction(const CoeffArray& data , const int xpos , const int ypos ) const;
    00194
    00196         void DecodeCoeffBlock(const CodeBlock& code_block , CoeffArray& out_data);
    00197     };
    00198
    00199
    00201
    00206     class IntraDCBandCodec: public GenericIntraDCBandCodec<ArithCodec<CoeffArray> >
    00207     {
    00208     public:
    00210
    00216         IntraDCBandCodec(SubbandByteIO* subband_byteio,
    00217                          size_t number_of_contexts,
    00218                          const SubbandList& band_list)
    00219           : GenericIntraDCBandCodec<ArithCodec<CoeffArray> >(subband_byteio,
    00220                                               number_of_contexts,
    00221                                               band_list){}
    00222
    00223
    00224     private:
    00226         void DoWorkCode(CoeffArray& in_data);                    //overridden from the base class
    00227
    00229         void DoWorkDecode(CoeffArray& out_data);
    00230
    00232         void CodeCoeff(CoeffArray& in_data, const int xpos, const int ypos);
    00233
    00235         void DecodeCoeff(CoeffArray& out_data, const int xpos, const int ypos);
    00236
    00238         IntraDCBandCodec(const IntraDCBandCodec& cpy);
    00239
    00241         IntraDCBandCodec& operator=(const IntraDCBandCodec& rhs);
    00242
    00243     private:
    00244         CoeffArray m_dc_pred_res;
    00245     };
    00246
    00247 }// end namespace dirac
    00248 #endif

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