source: 3DVCSoftware/branches/0.2-poznan-univ/source/Lib/TLibDecoder/TDecBinCoderCABAC.cpp @ 15

Last change on this file since 15 was 5, checked in by hhi, 13 years ago

Clean version with cfg-files

  • Property svn:eol-style set to native
File size: 3.5 KB
Line 
1/* The copyright in this software is being made available under the BSD
2 * License, included below. This software may be subject to other third party
3 * and contributor rights, including patent rights, and no such rights are
4 * granted under this license.
5 *
6 * Copyright (c) 2010-2011, ISO/IEC
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 *
12 *  * Redistributions of source code must retain the above copyright notice,
13 *    this list of conditions and the following disclaimer.
14 *  * Redistributions in binary form must reproduce the above copyright notice,
15 *    this list of conditions and the following disclaimer in the documentation
16 *    and/or other materials provided with the distribution.
17 *  * Neither the name of the ISO/IEC nor the names of its contributors may
18 *    be used to endorse or promote products derived from this software without
19 *    specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
31 * THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34
35
36/** \file     TDecBinCoderCABAC.cpp
37    \brief    binary entropy decoder of CABAC
38*/
39
40#include "TDecBinCoderCABAC.h"
41
42
43TDecBinCABAC::TDecBinCABAC()
44: m_pcTComBitstream( 0 )
45{
46}
47
48TDecBinCABAC::~TDecBinCABAC()
49{
50}
51
52Void
53TDecBinCABAC::init( TComBitstream* pcTComBitstream )
54{
55  m_pcTComBitstream = pcTComBitstream;
56}
57
58Void
59TDecBinCABAC::uninit()
60{
61  m_pcTComBitstream = 0;
62}
63
64Void
65TDecBinCABAC::start()
66{
67  m_pcTComBitstream->setModeSbac();
68 
69  m_uiRange    = 510;
70  m_uiValue    = 0;
71  for( UInt ui = 0; ui < 9; ui++ )
72  {
73    xReadBit( m_uiValue );
74  }
75}
76
77Void
78TDecBinCABAC::finish()
79{
80}
81
82Void
83TDecBinCABAC::decodeBin( UInt& ruiBin, ContextModel &rcCtxModel )
84{
85  UInt  uiLPS   = TComCABACTables::sm_aucLPSTable[ rcCtxModel.getState() ][ ( m_uiRange >> 6 ) & 3 ];
86  m_uiRange    -= uiLPS;
87  if( m_uiValue < m_uiRange )
88  {
89    ruiBin      = rcCtxModel.getMps();
90    rcCtxModel.updateMPS();
91  }
92  else
93  {
94    m_uiValue  -= m_uiRange;
95    m_uiRange   = uiLPS;
96    ruiBin      = 1 - rcCtxModel.getMps();
97    rcCtxModel.updateLPS();
98  }
99  while( m_uiRange < 256 )
100  {
101    m_uiRange  += m_uiRange;
102    xReadBit( m_uiValue );
103  }
104}
105
106Void
107TDecBinCABAC::decodeBinEP( UInt& ruiBin )
108{
109  xReadBit( m_uiValue );
110  if( m_uiValue >= m_uiRange )
111  {
112    ruiBin      = 1;
113    m_uiValue  -= m_uiRange;
114  }
115  else
116  {
117    ruiBin      = 0;
118  }
119}
120
121Void
122TDecBinCABAC::decodeBinTrm( UInt& ruiBin )
123{
124  m_uiRange -= 2;
125  if( m_uiValue >= m_uiRange )
126  {
127    ruiBin = 1;
128  }
129  else
130  {
131    ruiBin = 0;
132    while( m_uiRange < 256 )
133    {
134      m_uiRange += m_uiRange;
135      xReadBit( m_uiValue );
136    }
137  }
138}
139
140Void 
141TDecBinCABAC::xReadBit( UInt& ruiVal )
142{
143  UInt uiBit = 0;
144  m_pcTComBitstream->read( 1, uiBit );
145  ruiVal  = ( ruiVal << 1 ) | uiBit;
146}
Note: See TracBrowser for help on using the repository browser.