# 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 1.25 2007/05/01 14:51:14 asuraparaju Exp $ $Name: Dirac_0_7_0 $
    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
    00060     class BandCodec: public ArithCodec<PicArray>
    00061     {
    00062     public:
    00063
    00065
    00073         BandCodec(SubbandByteIO* subband_byteio,
    00074                   size_t number_of_contexts,
    00075                   const SubbandList& band_list,
    00076                   int band_num,
    00077                   const bool is_intra);
    00078
    00079     protected:
    00081         inline void CodeVal( PicArray& in_data , const int xpos , const int ypos , const ValueType val);
    00082
    00084         inline void DecodeVal(PicArray& out_data , const int xpos , const int ypos );
    00085
    00087         void CodeQIndexOffset( const int offset );
    00088
    00090         int DecodeQIndexOffset();
    00091
    00093         inline void SetToVal( const CodeBlock& code_block , PicArray& pic_data , const ValueType val);
    00094
    00096         inline void ClearBlock( const CodeBlock& code_block , PicArray& pic_data);
    00097
    00098     private:
    00099         //functions
    00100         // Overridden from the base class
    00101         virtual void DoWorkCode(PicArray& in_data);
    00102         // Ditto
    00103         virtual void DoWorkDecode(PicArray& out_data);
    00104
    00105         virtual void CodeCoeffBlock(const CodeBlock& code_block , PicArray& in_data);
    00106         virtual void DecodeCoeffBlock(const CodeBlock& code_block , PicArray& out_data);
    00107
    00109         inline int ChooseFollowContext( const int bin_number ) const;
    00110
    00112         inline int ChooseInfoContext() const;
    00113
    00115         inline int ChooseSignContext(const PicArray& data , const int xpos , const int ypos ) const;
    00116
    00118         BandCodec(const BandCodec& cpy);
    00120         BandCodec& operator=(const BandCodec& rhs);
    00121
    00122     protected:
    00123
    00125         bool m_is_intra;
    00126
    00128         int m_bnum;
    00129
    00131         const Subband m_node;
    00132
    00134         int m_last_qf_idx;
    00135
    00137         int m_qf;
    00138
    00140         ValueType m_offset;
    00141
    00143         bool m_nhood_nonzero;
    00144
    00146         Subband m_pnode;
    00147
    00149         int m_pxp, m_pyp, m_pxl, m_pyl;
    00150
    00152         int m_pxpos, m_pypos;
    00153
    00155         bool m_parent_notzero;
    00156
    00157     };
    00158
    00160
    00164     class LFBandCodec: public BandCodec
    00165     {
    00166     public:
    00168
    00176         LFBandCodec(SubbandByteIO* subband_byteio,
    00177                     size_t number_of_contexts,
    00178                     const SubbandList& band_list,
    00179                     int band_num,
    00180                     const bool is_intra)
    00181                     : BandCodec(subband_byteio,number_of_contexts,band_list,
    00182                                 band_num,is_intra){}
    00183
    00184     private:
    00185         // Overridden from the base class
    00186         void DoWorkCode(PicArray& in_data);
    00187         // Ditto
    00188         void DoWorkDecode(PicArray& out_data);
    00189
    00190         void CodeCoeffBlock(const CodeBlock& code_block , PicArray& in_data);
    00191         void DecodeCoeffBlock(const CodeBlock& code_block , PicArray& out_data);
    00192
    00194         LFBandCodec(const LFBandCodec& cpy);
    00196         LFBandCodec& operator=(const LFBandCodec& rhs);
    00197
    00198     };
    00199
    00200
    00202     //Finally,special class incorporating prediction for the DC band of intra frames//
    00204
    00206
    00210     class IntraDCBandCodec: public BandCodec
    00211     {
    00212     public:
    00214
    00220         IntraDCBandCodec(SubbandByteIO* subband_byteio,
    00221                          size_t number_of_contexts,
    00222                          const SubbandList& band_list)
    00223           : BandCodec(subband_byteio,number_of_contexts,band_list,
    00224                       band_list.Length(), true){}
    00225
    00226
    00227     private:
    00228         void DoWorkCode(PicArray& in_data);                    //overridden from the base class
    00229         void DoWorkDecode(PicArray& out_data); //ditto
    00230
    00231         void CodeCoeffBlock(const CodeBlock& code_block , PicArray& in_data);
    00232         void DecodeCoeffBlock(const CodeBlock& code_block , PicArray& out_data);
    00233
    00235         IntraDCBandCodec(const IntraDCBandCodec& cpy);
    00236
    00238         IntraDCBandCodec& operator=(const IntraDCBandCodec& rhs);
    00239
    00241         ValueType GetPrediction(const PicArray& data , const int xpos , const int ypos ) const;
    00242
    00243     private:
    00244         PicArray m_dc_pred_res;
    00245     };
    00246
    00247
    00248 }// end namespace dirac
    00249 #endif

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