# Dirac - A Video Codec

Created by the British Broadcasting Corporation.

# byteio.h

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    00001 /* ***** BEGIN LICENSE BLOCK *****
    00002 *
    00003 * $Id: byteio.h,v 1.5 2007/03/19 16:18:59 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): Andrew Kennedy (Original Author),
    00024 *                 Anuradha Suraparaju
    00025 *
    00026 * Alternatively, the contents of this file may be used under the terms of
    00027 * the GNU General Public License Version 2 (the "GPL"), or the GNU Lesser
    00028 * Public License Version 2.1 (the "LGPL"), in which case the provisions of
    00029 * the GPL or the LGPL are applicable instead of those above. If you wish to
    00030 * allow use of your version of this file only under the terms of the either
    00031 * the GPL or LGPL and not to allow others to use your version of this file
    00032 * under the MPL, indicate your decision by deleting the provisions above
    00033 * and replace them with the notice and other provisions required by the GPL
    00034 * or LGPL. If you do not delete the provisions above, a recipient may use
    00035 * your version of this file under the terms of any one of the MPL, the GPL
    00036 * or the LGPL.
    00037 * ***** END LICENSE BLOCK ***** */
    00038
    00042 #ifndef byteio_h
    00043 #define byteio_h
    00044
    00045 // SYSTEM INCLUDES
    00046 #include <iostream>             // IO classes
    00047 #include <sstream>              // IO classes
    00048 #include <iomanip>              // setw
    00049
    00050 //LOCAL INCLUDEs
    00051 #include <libdirac_byteio/dirac_byte_stats.h>   // stores stats
    00052
    00053 namespace dirac
    00054 {
    00055
    00056     // BIT DEFS
    00057     #define BIT_ZERO 0
    00058     #define BIT_ONE 1
    00059
    00060     // most significant bit in a character
    00061     #define MS_BIT                (1 << (CHAR_BIT - 1))
    00062
    00063     /* array index for character containing bit */
    00064     //#define BIT_IN_CHAR(bit)      (1 << (CHAR_BIT-1-bit))
    00065     #define BIT_IN_CHAR(bit)      (1 << bit)
    00066
    00067
    00071    class ByteIO
    00072    {
    00073    public:
    00074
    00079        ByteIO(bool new_stream=true);
    00080
    00085        ByteIO(const ByteIO& stream_data);
    00086
    00090        virtual ~ByteIO();
    00091
    00096        virtual void CollateByteStats(DiracByteStats& dirac_byte_stats)
    00097        { dirac_byte_stats.Clear(); }
    00098
    00102         virtual const std::string GetBytes();
    00103
    00107         int GetReadBytePosition() const { return mp_stream->tellg();};
    00108
    00109
    00113         virtual int GetSize() const;
    00114
    00119         void SetByteParams(const ByteIO& byte_io);
    00120
    00124         void ByteAlignOutput();
    00125
    00130         void OutputVarLengthUint(const unsigned int& value);
    00131
    00132     protected:
    00133
    00134         inline bool CanRead() const { return(!mp_stream->eof()); }
    00135
    00136         inline bool GetBit(unsigned char& c, int pos) const { return (c & BIT_IN_CHAR(pos)); }
    00137
    00138         inline void SetBit(unsigned char& c, int pos) const { c |= BIT_IN_CHAR(pos); }
    00139
    00140         inline void SetBits(unsigned char& c, unsigned char bits) const { c |= bits; }
    00141
    00145         void ByteAlignInput();
    00146
    00147
    00151         bool InputBit();
    00152
    00158         void InputBytes(char* data, int count)
    00159         {
    00160             //int j=mp_stream->tellg();
    00161             mp_stream->read(data, count);
    00162
    00163             //int h=mp_stream->tellg();
    00164         }
    00165
    00170         int InputVarLengthInt();
    00171
    00176         unsigned int InputVarLengthUint();
    00177
    00183         inline unsigned int InputFixedLengthUint(const int byte_size) {
    00184            unsigned int val=0;
    00185            for(int i=0; i < byte_size; ++i)
    00186            {
    00187                val <<= 8;
    00188                val += (unsigned char)mp_stream->get();
    00189            }
    00190            m_num_bytes+=byte_size;
    00191            return val;
    00192         }
    00193
    00197         inline unsigned char InputUnByte() {m_num_bytes++ ; return mp_stream->get(); }
    00198
    00202         inline std::string InputUnString(const int count)
    00203         {
    00204             std::string str;
    00205             for(int index=0; index < count; ++index)
    00206                 str.push_back(InputUnByte());
    00207             return str;
    00208         }
    00209
    00214         void OutputBit(const bool& bit);
    00215
    00216
    00220         void OutputBytes(const std::string& bytes) {
    00221            int cur_pos = mp_stream->tellg();
    00222           mp_stream->str(mp_stream->str()+bytes);
    00223            m_num_bytes+=bytes.size();
    00224         //   *mp_stream << bytes;
    00225            mp_stream->seekg(std::max(cur_pos,0), std::ios_base::beg);
    00226         }
    00227
    00231         inline void OutputCurrentByte()
    00232         {
    00233             if (m_current_pos)
    00234             {
    00235                 *mp_stream << (m_current_byte);
    00236                 ++m_num_bytes;
    00237                 m_current_pos = 0;
    00238                 m_current_byte = 0;
    00239             }
    00240         };
    00241
    00246        void OutputVarLengthInt(const int val);
    00247
    00253        inline void OutputFixedLengthUint(const unsigned int& value, const int& length)
    00254        {
    00255            for(int i=length-1; i >=0 ; --i)
    00256            {
    00257               unsigned char cp = (value>>(i*8))&0xff;
    00258                *mp_stream << cp;
    00259            }
    00260            m_num_bytes+=length;
    00261        }
    00262
    00267        void RemoveRedundantBytes(const int count);
    00268
    00269        inline void SeekGet(const int offset, std::ios_base::seekdir dir)
    00270        {
    00271            mp_stream->seekg(offset, dir);
    00272        }
    00273
    00277        std::stringstream*    mp_stream;
    00278
    00279
    00280    private:
    00281
    00285        friend class ArithCodecBase;
    00286
    00290        unsigned char m_current_byte;
    00291
    00295        int m_current_pos;
    00296
    00300        int m_num_bytes;
    00301
    00305        bool m_new_stream;
    00306
    00307
    00308    protected:
    00309
    00310
    00311    };
    00312
    00313
    00314
    00315 } // namespace dirac
    00316
    00317 #endif

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