/* ====================================================================================================================

  The copyright in this software is being made available under the License included below.
  This software may be subject to other third party and   contributor rights, including patent rights, and no such
  rights are granted under this license.

  Copyright (c) 2010, SAMSUNG ELECTRONICS CO., LTD. and BRITISH BROADCASTING CORPORATION
  All rights reserved.

  Redistribution and use in source and binary forms, with or without modification, are permitted only for
  the purpose of developing standards within the Joint Collaborative Team on Video Coding and for testing and
  promoting such standards. The following conditions are required to be met:

    * Redistributions of source code must retain the above copyright notice, this list of conditions and
      the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
      the following disclaimer in the documentation and/or other materials provided with the distribution.
    * Neither the name of SAMSUNG ELECTRONICS CO., LTD. nor the name of the BRITISH BROADCASTING CORPORATION
      may be used to endorse or promote products derived from this software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================================================================
*/

/** \file     TComBitStream.h
    \brief    class for handling bitstream (header)
*/

#ifndef __COMBITSTREAM__
#define __COMBITSTREAM__

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#include <stdio.h>
#include <assert.h>
#include "CommonDef.h"

// ====================================================================================================================
// Class definition
// ====================================================================================================================

/// pure virtual class for basic bit handling
class TComBitIf
{
public:
  virtual Void        writeAlignOne         () {};
  virtual Void        write                 ( UInt uiBits, UInt uiNumberOfBits )  = 0;
  virtual Void        resetBits             ()                                    = 0;
  virtual UInt        getNumberOfWrittenBits()                                    = 0;
  virtual ~TComBitIf() {}
};

/// class for handling bitstream
class TComBitstream : public TComBitIf
{
protected:
  UInt*       m_apulStreamPacketBegin;
  UInt*       m_pulStreamPacket;
  UInt        m_uiBufSize;
  
  UInt        m_uiBitSize;
  Int         m_iValidBits;
  
  UInt        m_ulCurrentBits;
  UInt        m_uiBitsWritten;
  
  UInt        m_uiDWordsLeft;
  UInt        m_uiBitsLeft;
  UInt        m_uiNextBits;
  
  UInt xSwap ( UInt ui )
  {
    // heiko.schwarz@hhi.fhg.de: support for BSD systems as proposed by Steffen Kamp [kamp@ient.rwth-aachen.de]
#ifdef MSYS_BIG_ENDIAN
    return ui;
#else
    UInt ul2;
    
    ul2  = ui>>24;
    ul2 |= (ui>>8) & 0x0000ff00;
    ul2 |= (ui<<8) & 0x00ff0000;
    ul2 |= ui<<24;
    
    return ul2;
#endif
  }
  
  // read one word
  __inline Void xReadNextWord ();
  
public:
  TComBitstream()             {}
  virtual ~TComBitstream()    {}
  
  // create / destroy
  Void        create          ( UInt uiSizeInBytes );
  Void        destroy         ();
  
  // interface for encoding
  Void        write           ( UInt uiBits, UInt uiNumberOfBits );
  Void        writeAlignOne   ();
  Void        writeAlignZero  ();
  Void        convertRBSPToPayload( UInt uiStartPos = 0);
  // interface for decoding
  Void        initParsingConvertPayloadToRBSP( const UInt uiBytesRead );
  Void        initParsing     ( UInt uiNumBytes );
#if LCEC_INTRA_MODE || QC_LCEC_INTER_MODE
  Void        pseudoRead      ( UInt uiNumberOfBits, UInt& ruiBits );
#endif
  Void        read            ( UInt uiNumberOfBits, UInt& ruiBits );
  Void        readAlignOne    ();
  
  // reset internal status
  Void        resetBits       ()
  {
    m_uiBitSize = 0;
    m_iValidBits = 32;
    m_ulCurrentBits = 0;
    m_uiBitsWritten = 0;
  }
  
  // utility functions
  UInt*       getStartStream()          { return m_apulStreamPacketBegin;               }
  UInt*       getBuffer()               { return  m_pulStreamPacket;                    }
  Int         getBitsUntilByteAligned() { return m_iValidBits & (0x7);                  }
  Void        setModeSbac()             { m_uiBitsLeft = 8*((m_uiBitsLeft+7)/8);        } // stop bit + trailing stuffing bits
  Bool        isWordAligned()           { return  (0 == (m_iValidBits & (0x1f)));       }
  UInt        getNumberOfWrittenBits()  { return  m_uiBitsWritten;                      }
  Void        flushBuffer();
  Void        rewindStreamPacket()      { m_pulStreamPacket = m_apulStreamPacketBegin;  }
  UInt        getBitsLeft()             { return  m_uiBitsLeft;                         }
};

#endif

