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 1.11 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): 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 #include <climits>              // CHAR_BIT
00050 
00051 //LOCAL INCLUDEs
00052 #include <libdirac_byteio/dirac_byte_stats.h>   // stores stats
00053 
00054 namespace dirac
00055 {
00056     
00057     // BIT DEFS
00058     #define BIT_ZERO 0
00059     #define BIT_ONE 1
00060 
00061     // most significant bit in a character 
00062     #define MS_BIT                (1 << (CHAR_BIT - 1))
00063 
00064     /* array index for character containing bit */
00065     //#define BIT_IN_CHAR(bit)      (1 << (CHAR_BIT-1-bit))
00066     #define BIT_IN_CHAR(bit)      (1 << bit)
00067  
00068 
00072    class ByteIO
00073    {
00074    public:
00075        
00080        ByteIO(bool new_stream=true);
00081 
00086        ByteIO(const ByteIO& stream_data);
00087 
00091        virtual ~ByteIO();
00092 
00097        virtual void CollateByteStats(DiracByteStats& dirac_byte_stats) 
00098        { dirac_byte_stats.Clear(); }
00099 
00103         virtual const std::string GetBytes();
00104 
00108         int GetReadBytePosition() const { return mp_stream->tellg();};
00109 
00110 
00114         virtual int GetSize() const;
00115 
00120         void SetByteParams(const ByteIO& byte_io);
00121 
00125         void ByteAlignOutput();
00126 
00131         //void OutputVarLengthUint(const unsigned int& value);
00132         void WriteUint(unsigned int value);
00133 
00137          void SetBitsLeft(int left_bits) { m_bits_left = left_bits; }
00138 
00142          int BitsLeft(void) { return m_bits_left; }
00143 
00144     protected:
00145 
00146         inline bool CanRead() const { return(!mp_stream->eof()); }
00147 
00148         inline bool GetBit(unsigned char& c, int pos) const { return (c & BIT_IN_CHAR(pos)); }
00149 
00150         inline void SetBit(unsigned char& c, int pos) const { c |= BIT_IN_CHAR(pos); }
00151 
00152         inline void SetBits(unsigned char& c, unsigned char bits) const { c |= bits; }
00153 
00157         void ByteAlignInput();
00158 
00159 
00163         bool ReadBool();
00164 
00168         bool ReadBoolB();
00169 
00173         int ReadBit();
00174 
00178         int ReadBitB();
00179 
00185         unsigned int ReadNBits(int count);
00186 
00192         void InputBytes(char* data, int count)
00193         {
00194             //int j=mp_stream->tellg();
00195             mp_stream->read(data, count);
00196 
00197             //int h=mp_stream->tellg();
00198         }
00199 
00203         void FlushInputB();
00204 
00209         //int InputVarLengthInt();
00210         int ReadSint();
00211 
00216         int ReadSintB();
00217 
00222         //unsigned int InputVarLengthUint();
00223         unsigned int ReadUint();
00224 
00229         //unsigned int InputVarLengthUint();
00230         unsigned int ReadUintB();
00231 
00237         //inline unsigned int InputFixedLengthUint(const int byte_size) { 
00238         inline unsigned int ReadUintLit(const int byte_size) { 
00239            unsigned int val=0; 
00240            for(int i=0; i < byte_size; ++i)
00241            {
00242                val <<= 8;
00243                val += (unsigned char)mp_stream->get();
00244            }
00245            m_num_bytes+=byte_size;
00246            return val;
00247         } 
00248 
00252         inline unsigned char InputUnByte() {m_num_bytes++ ; return mp_stream->get(); }
00253 
00257         inline std::string InputUnString(const int count) 
00258         {
00259             std::string str;
00260             for(int index=0; index < count; ++index)
00261                 str.push_back(InputUnByte());
00262             return str;
00263         }
00264 
00269         void WriteBit(const bool& bit);
00270 
00276         int WriteNBits(unsigned int val);
00277 
00283         void WriteNBits(unsigned int val, int count);
00284 
00285 
00286 
00290         void OutputBytes(const std::string& bytes) {
00291            int cur_pos = mp_stream->tellg();
00292           mp_stream->str(mp_stream->str()+bytes);
00293            m_num_bytes+=bytes.size();
00294         //   *mp_stream << bytes;
00295            mp_stream->seekg(std::max(cur_pos,0), std::ios_base::beg);
00296         }
00297 
00301         inline void OutputCurrentByte()
00302         {
00303             if (m_current_pos)
00304             {
00305                 *mp_stream << (m_current_byte);
00306                 ++m_num_bytes;
00307                 m_current_pos = 0;
00308                 m_current_byte = 0;
00309             }
00310         };
00311 
00316        //void OutputVarLengthInt(const int val);
00317        void WriteSint(int val);
00318 
00324        //inline void OutputFixedLengthUint(const unsigned int& value, const int& length)
00325        inline void WriteUintLit(const unsigned int& value, const int& length)
00326        {
00327            for(int i=length-1; i >=0 ; --i)
00328            {
00329               unsigned char cp = (value>>(i*8))&0xff; 
00330                *mp_stream << cp;
00331            }
00332            m_num_bytes+=length;
00333        }
00334        
00339        void RemoveRedundantBytes(const int count);
00340 
00341        inline void SeekGet(const int offset, std::ios_base::seekdir dir) 
00342        {
00343            mp_stream->seekg(offset, dir);
00344        }
00345 
00349        std::stringstream*    mp_stream;
00350 
00351 
00352    private:
00353        
00357        friend class ArithCodecBase;
00358 
00362        friend class ArithCodecToVLCAdapter;
00363 
00367        unsigned char m_current_byte;
00368             
00372        int m_current_pos;
00373 
00377        int m_num_bytes;
00378        
00382        bool m_new_stream;
00383         
00387        int m_bits_left;
00388    protected:
00389 
00390         
00391    };
00392 
00393 
00394 
00395 } // namespace dirac
00396 
00397 #endif

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