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/** \file     ContextModelling.h

 *  \brief    Classes providing probability descriptions and contexts (header)

 */

#pragma once

#include "CommonDef.h"

#include "Contexts.h"

#include "Slice.h"

#include "Unit.h"

#include "UnitPartitioner.h"

#include <bitset>

#include "CommonLib/dtrace_next.h"

namespace vvdec

{

struct CtxTpl

{

  // lower 5 bits are absSum1, upper 3 bits are numPos

  uint8_t ctxTpl;

};

struct CoeffCodingContext

{

public:

  CoeffCodingContext( const TransformUnit& tu, ComponentID component, bool signHide, CtxTpl *tplBuf );

public:

  void  initSubblock     ( int SubsetId, bool sigGroupFlag = false );

public:

  void  setSigGroup     ()                      { m_sigCoeffGroupFlag.set( m_subSetPos ); }

  bool  noneSigGroup    ()                      { return m_sigCoeffGroupFlag.none(); }

  int   lastSubSet      ()                      { return ( maxNumCoeff() - 1 ) >> log2CGSize(); }

  bool  isLastSubSet    ()                      { return lastSubSet() == m_subSetId; }

  bool  only1stSigGroup ()                      { return m_sigCoeffGroupFlag.count()-m_sigCoeffGroupFlag[lastSubSet()]==0; }

  void  setScanPosLast  ( int       posLast )   { m_scanPosLast = posLast; }

public:

  int             subSetId        ()                        const { return m_subSetId; }

  int             subSetPos       ()                        const { return m_subSetPos; }

  int             cgPosY          ()                        const { return m_subSetPosY; }

  int             cgPosX          ()                        const { return m_subSetPosX; }

  unsigned        width           ()                        const { return m_width; }

  unsigned        height          ()                        const { return m_height; }

  unsigned        log2CGSize      ()                        const { return m_log2CGSize; }

  unsigned        log2CGWidth     ()                        const { return m_log2CGWidth; }

  unsigned        log2CGHeight    ()                        const { return m_log2CGHeight; }

  unsigned        log2BlockWidth  ()                        const { return m_log2BlockWidth; }

  unsigned        log2BlockHeight ()                        const { return m_log2BlockHeight; }

  unsigned        log2BlockSize   ()                        const { return m_log2BlockSize; }

  int             maxLog2TrDRange ()                        const { return m_maxLog2TrDynamicRange; }

  unsigned        maxNumCoeff     ()                        const { return m_maxNumCoeff; }

  int             scanPosLast     ()                        const { return m_scanPosLast; }

  int             minSubPos       ()                        const { return m_minSubPos; }

  int             maxSubPos       ()                        const { return m_maxSubPos; }

  bool            isLast          ()                        const { return ( ( m_scanPosLast >> m_log2CGSize ) == m_subSetId ); }

  bool            isNotFirst      ()                        const { return ( m_subSetId != 0 ); }

  bool            isSigGroup      ()                        const { return m_sigCoeffGroupFlag[ m_subSetPos ]; }

  bool            signHiding      ()                        const { return m_signHiding; }

  bool            hideSign        ( int       posFirst,

                                    int       posLast   )   const { return ( m_signHiding && ( posLast - posFirst >= SBH_THRESHOLD ) ); }

  unsigned        blockPos        ( int       scanPos   )   const { return m_scan[ scanPos ]; }

  unsigned        posX            ( int       blkPos    )   const { return blkPos & ( ( 1 << m_log2BlockWidth ) - 1 ); }

  unsigned        posY            ( int       blkPos    )   const { return blkPos >> m_log2BlockWidth; }

  unsigned        maxLastPosX     ()                        const { return m_maxLastPosX; }

  unsigned        maxLastPosY     ()                        const { return m_maxLastPosY; }

  unsigned        lastXCtxId      ( unsigned  posLastX  )   const { return m_CtxSetLastX( m_lastOffsetX + ( posLastX >> m_lastShiftX ) ); }

  unsigned        lastYCtxId      ( unsigned  posLastY  )   const { return m_CtxSetLastY( m_lastOffsetY + ( posLastY >> m_lastShiftY ) ); }

  int             numCtxBins      ()                        const { return   m_remainingContextBins;      }

  void            setNumCtxBins   ( int n )                       {          m_remainingContextBins  = n; }

  unsigned        sigGroupCtxId   ( bool ts = false     )   const { return ts ? m_sigGroupCtxIdTS : m_sigGroupCtxId; }

  bool            bdpcm           ()                        const { return m_bdpcm; }

  int             regBinLimit     ()                        const { return m_regBinLimit; }

  void            setRegBinLimit  ( int n )                       {        m_regBinLimit = n; }

  void            decNumCtxBins   (int n)                         { m_remainingContextBins -= n; }

  void            incNumCtxBins   (int n)                         { m_remainingContextBins += n; }

  unsigned sigCtxIdAbs( const int blkPos, const int state )

  {

    const uint32_t posY     = blkPos >> m_log2BlockWidth;

    const uint32_t posX     = blkPos & ( ( 1 << m_log2BlockWidth ) - 1 );

    const int      diag     = posX + posY;

    const int      tplVal   = m_tplBuf[blkPos].ctxTpl;

    const int      numPos   = tplVal >> 5;

    const int      sumAbs   = tplVal & 31;

    int ctxOfs = std::min( ( sumAbs + 1 ) >> 1, 3 ) + ( diag < 2 ? 4 : 0 );

    if( isLuma( m_chType ) )

    {

      ctxOfs += diag < 5 ? 4 : 0;

    }

    m_tmplCpDiag = diag;

    m_tmplCpSum1 = sumAbs - numPos;

    return m_sigFlagCtxSet[std::max( 0, state-1 )]( ctxOfs );

  }

  void absVal1stPass( const int blkPos, TCoeffSig* coeff, const TCoeffSig absLevel1 )

  {

    CHECKD( !absLevel1, "absLevel1 has to non-zero!" );

    coeff[blkPos] = absLevel1;

    const uint32_t posY = blkPos >> m_log2BlockWidth;

    const uint32_t posX = blkPos & ( ( 1 << m_log2BlockWidth ) - 1 );

    auto update_deps = [&]( int offset )

    {

      auto& ctx   = m_tplBuf[blkPos - offset];

      ctx.ctxTpl += uint8_t( 32 + absLevel1 );

    };

    if( posY > 1 ) update_deps( 2 * m_width );

    if( posY > 0

     && posX > 0 ) update_deps( m_width + 1 );

    if( posY > 0 ) update_deps( m_width );

    if( posX > 1 ) update_deps( 2 );

    if( posX > 0 ) update_deps( 1 );

  }

  uint8_t ctxOffsetAbs()

  {

    int offset = 0;

    if( m_tmplCpDiag != -1 )

    {

      offset  = std::min( m_tmplCpSum1, 4 ) + 1;

      offset += ( !m_tmplCpDiag ? ( m_chType == CHANNEL_TYPE_LUMA ? 15 : 5 ) : m_chType == CHANNEL_TYPE_LUMA ? m_tmplCpDiag < 3 ? 10 : ( m_tmplCpDiag < 10 ? 5 : 0 ) : 0 );

    }

    return uint8_t(offset);

  }

  unsigned parityCtxIdAbs   ( uint8_t offset )  const { return m_parFlagCtxSet   ( offset ); }

  unsigned greater1CtxIdAbs ( uint8_t offset )  const { return m_gtxFlagCtxSet[1]( offset ); }

  unsigned greater2CtxIdAbs ( uint8_t offset )  const { return m_gtxFlagCtxSet[0]( offset ); }

  unsigned templateAbsSum( int blkPos, const TCoeffSig* coeff, int baseLevel )

  {

    const uint32_t   posY  = blkPos >> m_log2BlockWidth;

    const uint32_t   posX  = blkPos & ( ( 1 << m_log2BlockWidth ) - 1 );

    const TCoeffSig* pData = coeff + posX + ( posY << m_log2BlockWidth );

    int              sum   = 0;

    if (posX+2 < m_width)

    {

      sum += pData[1];

      sum += pData[2];

      if (posY+1 < m_height)

      {

        sum += pData[m_width + 1];

      }

    }

    else if (posX+1 < m_width)

    {

      sum += pData[1];

      if (posY+1 < m_height)

      {

        sum += pData[m_width + 1];

      }

    }

    if (posY+2 < m_height)

    {

      sum += pData[m_width];

      sum += pData[m_width << 1];

    }

    else if (posY+1 < m_height)

    {

      sum += pData[m_width];

    }

    return std::max(std::min(sum - 5 * baseLevel, 31), 0);

  }

  unsigned sigCtxIdAbsTS( int blkPos, const TCoeffSig* coeff )

  {

    const uint32_t   posY  = blkPos >> m_log2BlockWidth;

    const uint32_t   posX  = blkPos & ( ( 1 << m_log2BlockWidth ) - 1 );

    const TCoeffSig* posC  = coeff + posX + posY * m_width;

    int             numPos = 0;

#define UPDATE(x) {numPos+=!!x;}

    if( posX > 0 )

    {

      UPDATE( posC[-1] );

    }

    if( posY > 0 )

    {

      UPDATE( posC[-(int)m_width] );

    }

#undef UPDATE

    return m_tsSigFlagCtxSet( numPos );

  }

  unsigned parityCtxIdAbsTS   ()                  const { return m_tsParFlagCtxSet(      0 ); }

  unsigned greaterXCtxIdAbsTS ( uint8_t offset )  const { return m_tsGtxFlagCtxSet( offset ); }

  unsigned lrg1CtxIdAbsTS(int blkPos, const TCoeffSig* coeff, int bdpcm)

  {

    const uint32_t  posY = blkPos >> m_log2BlockWidth;

    const uint32_t  posX = blkPos & ( ( 1 << m_log2BlockWidth ) - 1 );

    const TCoeffSig*   posC = coeff + posX + posY * m_width;

    int             numPos = 0;

#define UPDATE(x) {numPos+=!!x;}

    if (bdpcm)

    {

      numPos = 3;

    }

    else

    {

      if (posX > 0)

      {

        UPDATE(posC[-1]);

      }

      if (posY > 0)

      {

        UPDATE(posC[-(int)m_width]);

      }

    }

#undef UPDATE

    return m_tsLrg1FlagCtxSet(numPos);

  }

  unsigned signCtxIdAbsTS(int blkPos, const TCoeffSig* coeff, int bdpcm)

  {

    const uint32_t  posY = blkPos >> m_log2BlockWidth;

    const uint32_t  posX = blkPos & ( ( 1 << m_log2BlockWidth ) - 1 );

    const TCoeffSig*   pData = coeff + posX + posY * m_width;

    int rightSign = 0, belowSign = 0;

    unsigned signCtx = 0;

    if (posX > 0)

    {

      rightSign = pData[-1];

    }

    if (posY > 0)

    {

      belowSign = pData[-(int)m_width];

    }

    if ((rightSign == 0 && belowSign == 0) || ((rightSign*belowSign) < 0))

    {

      signCtx = 0;

    }

    else if (rightSign >= 0 && belowSign >= 0)

    {

      signCtx = 1;

    }

    else

    {

      signCtx = 2;

    }

    if (bdpcm)

    {

      signCtx += 3;

    }

    DTRACE( g_trace_ctx, D_SYNTAX_RESI, "signCtxIdAbsTS() pos=(%d;%d)  signCtx=%d  rightSign=%d belowSign=%d\n", posX, posY, signCtx, rightSign, belowSign );

    return m_tsSignFlagCtxSet(signCtx);

  }

  void neighTS(int &rightPixel, int &belowPixel, int blkPos, const TCoeffSig* coeff)

  {

    const uint32_t  posY = blkPos >> m_log2BlockWidth;

    const uint32_t  posX = blkPos & ( ( 1 << m_log2BlockWidth ) - 1 );

    const TCoeffSig*   data = coeff + posX + posY * m_width;

    rightPixel = belowPixel = 0;

    if (posX > 0)

    {

      rightPixel = data[-1];

    }

    if (posY > 0)

    {

      belowPixel = data[-(int)m_width];

    }

  }

  int deriveModCoeff(int rightPixel, int belowPixel, int absCoeff, int bdpcm = 0)

  {

    if (absCoeff == 0)

      return 0;

    int pred1, absBelow = abs(belowPixel), absRight = abs(rightPixel);

    int absCoeffMod = absCoeff;

    if (bdpcm == 0)

    {

      pred1 = std::max(absBelow, absRight);

      if (absCoeff == pred1)

      {

        absCoeffMod = 1;

      }

      else

      {

        absCoeffMod = absCoeff < pred1 ? absCoeff + 1 : absCoeff;

      }

    }

    return(absCoeffMod);

  }

  int decDeriveModCoeff(int rightPixel, int belowPixel, int absCoeff)

  {

    if (absCoeff == 0)

      return 0;

    int pred1, absBelow = abs(belowPixel), absRight = abs(rightPixel);

    pred1 = std::max(absBelow, absRight);

    int absCoeffMod;

    if (absCoeff == 1 && pred1 > 0)

    {

      absCoeffMod = pred1;

    }

    else

    {

      absCoeffMod = absCoeff - (absCoeff <= pred1);

    }

    return(absCoeffMod);

  }

  unsigned templateAbsSumTS( int blkPos, const TCoeffSig* coeff )

  {

    return 1;

  }

private:

  // constant

  const ChannelType         m_chType;

  const unsigned            m_width;

  const unsigned            m_height;

  const unsigned            m_log2CGWidth;

  const unsigned            m_log2CGHeight;

  const unsigned            m_log2CGSize;

  const unsigned            m_widthInGroups;

  const unsigned            m_heightInGroups;

  const unsigned            m_log2BlockWidth;

  const unsigned            m_log2BlockHeight;

  const unsigned            m_log2BlockSize;

  const unsigned            m_maxNumCoeff;

  const bool                m_signHiding;

  const int                 m_maxLog2TrDynamicRange;

  const uint16_t*           m_scan;

  const uint16_t*           m_scanCG;

  const CtxSet              m_CtxSetLastX;

  const CtxSet              m_CtxSetLastY;

  const unsigned            m_maxLastPosX;

  const unsigned            m_maxLastPosY;

  const int                 m_lastOffsetX;

  const int                 m_lastOffsetY;

  const int                 m_lastShiftX;

  const int                 m_lastShiftY;

  // modified

  int                       m_scanPosLast;

  int                       m_subSetId;

  int                       m_subSetPos;

  int                       m_subSetPosX;

  int                       m_subSetPosY;

  int                       m_minSubPos;

  int                       m_maxSubPos;

  unsigned                  m_sigGroupCtxId;

  int                       m_tmplCpSum1;

  int                       m_tmplCpDiag;

  CtxSet                    m_sigFlagCtxSet[3];

  CtxSet                    m_parFlagCtxSet;

  CtxSet                    m_gtxFlagCtxSet[2];

  unsigned                  m_sigGroupCtxIdTS;

  CtxSet                    m_tsSigFlagCtxSet;

  CtxSet                    m_tsParFlagCtxSet;

  CtxSet                    m_tsGtxFlagCtxSet;

  CtxSet                    m_tsLrg1FlagCtxSet;

  CtxSet                    m_tsSignFlagCtxSet;

  int                       m_remainingContextBins;

  std::bitset<MLS_GRP_NUM>  m_sigCoeffGroupFlag;

  const bool                m_bdpcm;

  int                       m_regBinLimit;

  const bool                m_ts;

  CtxTpl*                   m_tplBuf;

};

class CUCtx

{

public:

  CUCtx()              : isDQPCoded(false), isChromaQpAdjCoded(false), qgStart(false), lfnstLastScanPos(false)

                         {

                           violatesLfnstConstrained[CHANNEL_TYPE_LUMA  ] = false;

                           violatesLfnstConstrained[CHANNEL_TYPE_CHROMA] = false;

                           violatesMtsCoeffConstraint                    = false;

                           mtsLastScanPos                                = false;

                         }

  CUCtx(int _qp)       : isDQPCoded(false), isChromaQpAdjCoded(false), qgStart(false), lfnstLastScanPos(false), qp(_qp)

                         {

                           violatesLfnstConstrained[CHANNEL_TYPE_LUMA  ] = false;

                           violatesLfnstConstrained[CHANNEL_TYPE_CHROMA] = false;

                           violatesMtsCoeffConstraint                    = false;

                           mtsLastScanPos                                = false;

                         }

  ~CUCtx() {}

public:

  bool      isDQPCoded;

  bool      isChromaQpAdjCoded;

  bool      qgStart;

  bool      lfnstLastScanPos;

  int8_t    qp;                   // used as a previous(last) QP and for QP prediction

  bool      violatesLfnstConstrained[MAX_NUM_CHANNEL_TYPE];

  bool      violatesMtsCoeffConstraint;

  bool      mtsLastScanPos;

};

class MergeCtx

{

public:

  MergeCtx() : numValidMergeCand( 0 ) { memset( mrgTypeNeighbours, 0, sizeof( mrgTypeNeighbours ) ); }

  ~MergeCtx() {}

public:

  MvField       mvFieldNeighbours [ MRG_MAX_NUM_CANDS << 1 ]; // double length for mv of both lists

  uint8_t       BcwIdx            [ MRG_MAX_NUM_CANDS      ];

  unsigned char interDirNeighbours[ MRG_MAX_NUM_CANDS      ];

  MergeType     mrgTypeNeighbours [ MRG_MAX_NUM_CANDS      ];

  int           numValidMergeCand;

  MvField       mmvdBaseMv        [MMVD_BASE_MV_NUM        ][2];

  void setMmvdMergeCandiInfo( CodingUnit& cu, int candIdx );

  bool          mmvdUseAltHpelIf  [ MMVD_BASE_MV_NUM ];

  bool          useAltHpelIf      [ MRG_MAX_NUM_CANDS ];

  void setMergeInfo         ( CodingUnit& cu, int candIdx );

  void init()               { numValidMergeCand = 0; memset( mrgTypeNeighbours, 0, sizeof( mrgTypeNeighbours ) ); }

};

class AffineMergeCtx

{

public:

  AffineMergeCtx() : numValidMergeCand( 0 ) { for ( unsigned i = 0; i < AFFINE_MRG_MAX_NUM_CANDS; i++ ) affineType[i] = AFFINEMODEL_4PARAM; }

  ~AffineMergeCtx() {}

public:

  MvField       mvFieldNeighbours [AFFINE_MRG_MAX_NUM_CANDS << 1][3]; // double length for mv of both lists

  unsigned char interDirNeighbours[AFFINE_MRG_MAX_NUM_CANDS     ];

  AffineModel   affineType        [AFFINE_MRG_MAX_NUM_CANDS     ];

  uint8_t       BcwIdx            [AFFINE_MRG_MAX_NUM_CANDS     ];

  int           numValidMergeCand;

  int           maxNumMergeCand;

  MotionBuf     subPuMvpMiBuf;

  MergeType     mergeType         [AFFINE_MRG_MAX_NUM_CANDS     ];

};

namespace DeriveCtx

{

void     CtxSplit     ( const CodingStructure& cs, Partitioner& partitioner, unsigned& ctxSpl, unsigned& ctxQt, unsigned& ctxHv, unsigned& ctxHorBt, unsigned& ctxVerBt, bool* canSplit = nullptr );

unsigned CtxModeConsFlag( const CodingStructure& cs, Partitioner& partitioner );

unsigned CtxQtCbf     ( const ComponentID compID, const bool prevCbCbf = false, const int ispIdx = 0 );

unsigned CtxInterDir  ( const CodingUnit& cu );

unsigned CtxSkipFlag  ( const CodingUnit& cu );

unsigned CtxAffineFlag( const CodingUnit& cu );

unsigned CtxPredModeFlag( const CodingUnit& cu );

unsigned CtxIBCFlag   (const CodingUnit& cu);

unsigned CtxMipFlag   ( const CodingUnit& cu );

}

}