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33 
34 
35 /** \file     ContextModel.h
36     \brief    context model class (header)
37 */
38 
39 #ifndef __CONTEXTMODEL__
40 #define __CONTEXTMODEL__
41 
42 #if _MSC_VER > 1000
43 #pragma once
44 #endif // _MSC_VER > 1000
45 
46 #include "CommonDef.h"
47 #include "TComRom.h"
48 
49 //! \ingroup TLibCommon
50 //! \{
51 
52 // ====================================================================================================================
53 // Class definition
54 // ====================================================================================================================
55 
56 /// context model class
57 class ContextModel
58 {
59 public:
ContextModel()60   ContextModel  ()                        { m_ucState = 0; m_binsCoded = 0; }
~ContextModel()61   ~ContextModel ()                        {}
62 
getState()63   UChar getState  ()                { return ( m_ucState >> 1 ); }                    ///< get current state
getMps()64   UChar getMps    ()                { return ( m_ucState  & 1 ); }                    ///< get curret MPS
setStateAndMps(UChar ucState,UChar ucMPS)65   Void  setStateAndMps( UChar ucState, UChar ucMPS) { m_ucState = (ucState << 1) + ucMPS; } ///< set state and MPS
66 
67   Void init ( Int qp, Int initValue );   ///< initialize state with initial probability
68 
updateLPS()69   Void updateLPS ()
70   {
71     m_ucState = m_aucNextStateLPS[ m_ucState ];
72   }
73 
updateMPS()74   Void updateMPS ()
75   {
76     m_ucState = m_aucNextStateMPS[ m_ucState ];
77   }
78 
getEntropyBits(Short val)79   Int getEntropyBits(Short val) { return m_entropyBits[m_ucState ^ val]; }
80 
81 #if FAST_BIT_EST
update(Int binVal)82   Void update( Int binVal )
83   {
84     m_ucState = m_nextState[m_ucState][binVal];
85   }
86   static Void buildNextStateTable();
getEntropyBitsTrm(Int val)87   static Int getEntropyBitsTrm( Int val ) { return m_entropyBits[126 ^ val]; }
88 #endif
setBinsCoded(UInt val)89   Void setBinsCoded(UInt val)   { m_binsCoded = val;  }
getBinsCoded()90   UInt getBinsCoded()           { return m_binsCoded;   }
91 
92 private:
93   UChar         m_ucState;                                                                  ///< internal state variable
94 
95   static const  UInt  m_totalStates = (1 << CONTEXT_STATE_BITS) * 2; //*2 for MPS = [0|1]
96   static const  UChar m_aucNextStateMPS[m_totalStates];
97   static const  UChar m_aucNextStateLPS[m_totalStates];
98   static const  Int   m_entropyBits    [m_totalStates];
99 #if FAST_BIT_EST
100   static UChar m_nextState[m_totalStates][2 /*MPS = [0|1]*/];
101 #endif
102   UInt          m_binsCoded;
103 };
104 
105 //! \}
106 
107 #endif
108 
109