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/** \file     TComWeightPrediction.h
    \brief    weighting prediction class (header)
*/

// Include files
#include "TComSlice.h"
#include "TComWeightPrediction.h"
#include "TComInterpolationFilter.h"

static inline Pel weightBidirY( Int w0, Pel P0, Int w1, Pel P1, Int round, Int shift, Int offset)
{
  return ClipY( ( (w0*(P0 + IF_INTERNAL_OFFS) + w1*(P1 + IF_INTERNAL_OFFS) + round + (offset << (shift-1))) >> shift ) );
}
static inline Pel weightBidirC( Int w0, Pel P0, Int w1, Pel P1, Int round, Int shift, Int offset)
{
  return ClipC( ( (w0*(P0 + IF_INTERNAL_OFFS) + w1*(P1 + IF_INTERNAL_OFFS) + round + (offset << (shift-1))) >> shift ) );
}

static inline Pel weightUnidirY( Int w0, Pel P0, Int round, Int shift, Int offset)
{
  return ClipY( ( (w0*(P0 + IF_INTERNAL_OFFS) + round) >> shift ) + offset );
}
static inline Pel weightUnidirC( Int w0, Pel P0, Int round, Int shift, Int offset)
{
  return ClipC( ( (w0*(P0 + IF_INTERNAL_OFFS) + round) >> shift ) + offset );
}

// ====================================================================================================================
// Class definition
// ====================================================================================================================
TComWeightPrediction::TComWeightPrediction()
{
}

/** weighted averaging for bi-pred
 * \param TComYuv* pcYuvSrc0
 * \param TComYuv* pcYuvSrc1
 * \param iPartUnitIdx
 * \param iWidth
 * \param iHeight
 * \param wpScalingParam *wp0
 * \param wpScalingParam *wp1
 * \param TComYuv* rpcYuvDst
 * \returns Void
 */
Void TComWeightPrediction::addWeightBi( TComYuv* pcYuvSrc0, TComYuv* pcYuvSrc1, UInt iPartUnitIdx, UInt iWidth, UInt iHeight, wpScalingParam *wp0, wpScalingParam *wp1, TComYuv* rpcYuvDst, Bool bRound )
{
  Int x, y;

  Pel* pSrcY0  = pcYuvSrc0->getLumaAddr( iPartUnitIdx );
  Pel* pSrcU0  = pcYuvSrc0->getCbAddr  ( iPartUnitIdx );
  Pel* pSrcV0  = pcYuvSrc0->getCrAddr  ( iPartUnitIdx );
  
  Pel* pSrcY1  = pcYuvSrc1->getLumaAddr( iPartUnitIdx );
  Pel* pSrcU1  = pcYuvSrc1->getCbAddr  ( iPartUnitIdx );
  Pel* pSrcV1  = pcYuvSrc1->getCrAddr  ( iPartUnitIdx );
  
  Pel* pDstY   = rpcYuvDst->getLumaAddr( iPartUnitIdx );
  Pel* pDstU   = rpcYuvDst->getCbAddr  ( iPartUnitIdx );
  Pel* pDstV   = rpcYuvDst->getCrAddr  ( iPartUnitIdx );
  
  // Luma : --------------------------------------------
  Int w0      = wp0[0].w;
  Int offset  = wp0[0].offset;
  Int shiftNum = IF_INTERNAL_PREC - g_bitDepthY;
  Int shift   = wp0[0].shift + shiftNum;
  Int round   = shift?(1<<(shift-1)) * bRound:0;
  Int w1      = wp1[0].w;

  UInt  iSrc0Stride = pcYuvSrc0->getStride();
  UInt  iSrc1Stride = pcYuvSrc1->getStride();
  UInt  iDstStride  = rpcYuvDst->getStride();
  for ( y = iHeight-1; y >= 0; y-- )
  {
    for ( x = iWidth-1; x >= 0; )
    {
      // note: luma min width is 4
      pDstY[x] = weightBidirY(w0,pSrcY0[x], w1,pSrcY1[x], round, shift, offset); x--;
      pDstY[x] = weightBidirY(w0,pSrcY0[x], w1,pSrcY1[x], round, shift, offset); x--;
      pDstY[x] = weightBidirY(w0,pSrcY0[x], w1,pSrcY1[x], round, shift, offset); x--;
      pDstY[x] = weightBidirY(w0,pSrcY0[x], w1,pSrcY1[x], round, shift, offset); x--;
    }
    pSrcY0 += iSrc0Stride;
    pSrcY1 += iSrc1Stride;
    pDstY  += iDstStride;
  }

  
  // Chroma U : --------------------------------------------
  w0      = wp0[1].w;
  offset  = wp0[1].offset;
  shiftNum = IF_INTERNAL_PREC - g_bitDepthC;
  shift   = wp0[1].shift + shiftNum;
  round   = shift?(1<<(shift-1)):0;
  w1      = wp1[1].w;

  iSrc0Stride = pcYuvSrc0->getCStride();
  iSrc1Stride = pcYuvSrc1->getCStride();
  iDstStride  = rpcYuvDst->getCStride();
  
  iWidth  >>=1;
  iHeight >>=1;
  
  for ( y = iHeight-1; y >= 0; y-- )
  {
    for ( x = iWidth-1; x >= 0; )
    {
      // note: chroma min width is 2
      pDstU[x] = weightBidirC(w0,pSrcU0[x], w1,pSrcU1[x], round, shift, offset); x--;
      pDstU[x] = weightBidirC(w0,pSrcU0[x], w1,pSrcU1[x], round, shift, offset); x--;
    }
    pSrcU0 += iSrc0Stride;
    pSrcU1 += iSrc1Stride;
    pDstU  += iDstStride;
  }

  // Chroma V : --------------------------------------------
  w0      = wp0[2].w;
  offset  = wp0[2].offset;
  shift   = wp0[2].shift + shiftNum;
  round   = shift?(1<<(shift-1)):0;
  w1      = wp1[2].w;

  for ( y = iHeight-1; y >= 0; y-- )
  {
    for ( x = iWidth-1; x >= 0; )
    {
      // note: chroma min width is 2
      pDstV[x] = weightBidirC(w0,pSrcV0[x], w1,pSrcV1[x], round, shift, offset); x--;
      pDstV[x] = weightBidirC(w0,pSrcV0[x], w1,pSrcV1[x], round, shift, offset); x--;
    }
    pSrcV0 += iSrc0Stride;
    pSrcV1 += iSrc1Stride;
    pDstV  += iDstStride;
  }
}

/** weighted averaging for uni-pred
 * \param TComYuv* pcYuvSrc0
 * \param iPartUnitIdx
 * \param iWidth
 * \param iHeight
 * \param wpScalingParam *wp0
 * \param TComYuv* rpcYuvDst
 * \returns Void
 */
Void TComWeightPrediction::addWeightUni( TComYuv* pcYuvSrc0, UInt iPartUnitIdx, UInt iWidth, UInt iHeight, wpScalingParam *wp0, TComYuv* rpcYuvDst )
{
  Int x, y;
  
  Pel* pSrcY0  = pcYuvSrc0->getLumaAddr( iPartUnitIdx );
  Pel* pSrcU0  = pcYuvSrc0->getCbAddr  ( iPartUnitIdx );
  Pel* pSrcV0  = pcYuvSrc0->getCrAddr  ( iPartUnitIdx );
  
  Pel* pDstY   = rpcYuvDst->getLumaAddr( iPartUnitIdx );
  Pel* pDstU   = rpcYuvDst->getCbAddr  ( iPartUnitIdx );
  Pel* pDstV   = rpcYuvDst->getCrAddr  ( iPartUnitIdx );
  
  // Luma : --------------------------------------------
  Int w0      = wp0[0].w;
  Int offset  = wp0[0].offset;
  Int shiftNum = IF_INTERNAL_PREC - g_bitDepthY;
  Int shift   = wp0[0].shift + shiftNum;
  Int round   = shift?(1<<(shift-1)):0;
  UInt  iSrc0Stride = pcYuvSrc0->getStride();
  UInt  iDstStride  = rpcYuvDst->getStride();
  
  for ( y = iHeight-1; y >= 0; y-- )
  {
    for ( x = iWidth-1; x >= 0; )
    {
      // note: luma min width is 4
      pDstY[x] = weightUnidirY(w0,pSrcY0[x], round, shift, offset); x--;
      pDstY[x] = weightUnidirY(w0,pSrcY0[x], round, shift, offset); x--;
      pDstY[x] = weightUnidirY(w0,pSrcY0[x], round, shift, offset); x--;
      pDstY[x] = weightUnidirY(w0,pSrcY0[x], round, shift, offset); x--;
    }
    pSrcY0 += iSrc0Stride;
    pDstY  += iDstStride;
  }
  
  // Chroma U : --------------------------------------------
  w0      = wp0[1].w;
  offset  = wp0[1].offset;
  shiftNum = IF_INTERNAL_PREC - g_bitDepthC;
  shift   = wp0[1].shift + shiftNum;
  round   = shift?(1<<(shift-1)):0;

  iSrc0Stride = pcYuvSrc0->getCStride();
  iDstStride  = rpcYuvDst->getCStride();
  
  iWidth  >>=1;
  iHeight >>=1;
  
  for ( y = iHeight-1; y >= 0; y-- )
  {
    for ( x = iWidth-1; x >= 0; )
    {
      // note: chroma min width is 2
      pDstU[x] = weightUnidirC(w0,pSrcU0[x], round, shift, offset); x--;
      pDstU[x] = weightUnidirC(w0,pSrcU0[x], round, shift, offset); x--;
    }
    pSrcU0 += iSrc0Stride;
    pDstU  += iDstStride;
  }

  // Chroma V : --------------------------------------------
  w0      = wp0[2].w;
  offset  = wp0[2].offset;
  shift   = wp0[2].shift + shiftNum;
  round   = shift?(1<<(shift-1)):0;

  for ( y = iHeight-1; y >= 0; y-- )
  {
    for ( x = iWidth-1; x >= 0; )
    {
      // note: chroma min width is 2
      pDstV[x] = weightUnidirC(w0,pSrcV0[x], round, shift, offset); x--;
      pDstV[x] = weightUnidirC(w0,pSrcV0[x], round, shift, offset); x--;
    }
    pSrcV0 += iSrc0Stride;
    pDstV  += iDstStride;
  }
}

//=======================================================
//  getWpScaling()
//=======================================================
/** derivation of wp tables
 * \param TComDataCU* pcCU
 * \param iRefIdx0
 * \param iRefIdx1
 * \param wpScalingParam *&wp0
 * \param wpScalingParam *&wp1
 * \param ibdi
 * \returns Void
 */
Void TComWeightPrediction::getWpScaling( TComDataCU* pcCU, Int iRefIdx0, Int iRefIdx1, wpScalingParam *&wp0, wpScalingParam *&wp1)
{
  assert(iRefIdx0 >= 0 || iRefIdx1 >= 0);
  
  TComSlice*      pcSlice       = pcCU->getSlice();
  TComPPS*        pps           = pcCU->getSlice()->getPPS();
  Bool            wpBiPred = pps->getWPBiPred();
  wpScalingParam* pwp;
  Bool            bBiDir        = (iRefIdx0>=0 && iRefIdx1>=0);
  Bool            bUniDir       = !bBiDir;

  if ( bUniDir || wpBiPred )
  { // explicit --------------------
    if ( iRefIdx0 >= 0 )
    {
      pcSlice->getWpScaling(REF_PIC_LIST_0, iRefIdx0, wp0);
    }
    if ( iRefIdx1 >= 0 )
    {
      pcSlice->getWpScaling(REF_PIC_LIST_1, iRefIdx1, wp1);
    }
  }
  else
  {
    assert(0);
  }

  if ( iRefIdx0 < 0 )
  {
    wp0 = NULL;
  }
  if ( iRefIdx1 < 0 )
  {
    wp1 = NULL;
  }

  if ( bBiDir )
  { // Bi-Dir case
    for ( Int yuv=0 ; yuv<3 ; yuv++ )
    {
      Int bitDepth = yuv ? g_bitDepthC : g_bitDepthY;
      wp0[yuv].w      = wp0[yuv].iWeight;
      wp0[yuv].o      = wp0[yuv].iOffset * (1 << (bitDepth-8));
      wp1[yuv].w      = wp1[yuv].iWeight;
      wp1[yuv].o      = wp1[yuv].iOffset * (1 << (bitDepth-8));
      wp0[yuv].offset = wp0[yuv].o + wp1[yuv].o;
      wp0[yuv].shift  = wp0[yuv].uiLog2WeightDenom + 1;
      wp0[yuv].round  = (1 << wp0[yuv].uiLog2WeightDenom);
      wp1[yuv].offset = wp0[yuv].offset;
      wp1[yuv].shift  = wp0[yuv].shift;
      wp1[yuv].round  = wp0[yuv].round;
    }
  }
  else
  {  // Unidir
    pwp = (iRefIdx0>=0) ? wp0 : wp1 ;
    for ( Int yuv=0 ; yuv<3 ; yuv++ )
    {
      Int bitDepth = yuv ? g_bitDepthC : g_bitDepthY;
      pwp[yuv].w      = pwp[yuv].iWeight;
      pwp[yuv].offset = pwp[yuv].iOffset * (1 << (bitDepth-8));
      pwp[yuv].shift  = pwp[yuv].uiLog2WeightDenom;
      pwp[yuv].round  = (pwp[yuv].uiLog2WeightDenom>=1) ? (1 << (pwp[yuv].uiLog2WeightDenom-1)) : (0);
    }
  }
}

/** weighted prediction for bi-pred
 * \param TComDataCU* pcCU
 * \param TComYuv* pcYuvSrc0
 * \param TComYuv* pcYuvSrc1
 * \param iRefIdx0
 * \param iRefIdx1
 * \param uiPartIdx
 * \param iWidth
 * \param iHeight
 * \param TComYuv* rpcYuvDst
 * \returns Void
 */
Void TComWeightPrediction::xWeightedPredictionBi( TComDataCU* pcCU, TComYuv* pcYuvSrc0, TComYuv* pcYuvSrc1, Int iRefIdx0, Int iRefIdx1, UInt uiPartIdx, Int iWidth, Int iHeight, TComYuv* rpcYuvDst )
{
  wpScalingParam  *pwp0, *pwp1;
  TComPPS         *pps = pcCU->getSlice()->getPPS();
  assert( pps->getWPBiPred());

  getWpScaling(pcCU, iRefIdx0, iRefIdx1, pwp0, pwp1);

  if( iRefIdx0 >= 0 && iRefIdx1 >= 0 )
  {
    addWeightBi(pcYuvSrc0, pcYuvSrc1, uiPartIdx, iWidth, iHeight, pwp0, pwp1, rpcYuvDst );
  }
  else if ( iRefIdx0 >= 0 && iRefIdx1 <  0 )
  {
    addWeightUni( pcYuvSrc0, uiPartIdx, iWidth, iHeight, pwp0, rpcYuvDst );
  }
  else if ( iRefIdx0 <  0 && iRefIdx1 >= 0 )
  {
    addWeightUni( pcYuvSrc1, uiPartIdx, iWidth, iHeight, pwp1, rpcYuvDst );
  }
  else
  {
    assert (0);
  }
}

/** weighted prediction for uni-pred
 * \param TComDataCU* pcCU
 * \param TComYuv* pcYuvSrc
 * \param uiPartAddr
 * \param iWidth
 * \param iHeight
 * \param eRefPicList
 * \param TComYuv*& rpcYuvPred
 * \param iPartIdx
 * \param iRefIdx
 * \returns Void
 */
Void TComWeightPrediction::xWeightedPredictionUni( TComDataCU* pcCU, TComYuv* pcYuvSrc, UInt uiPartAddr, Int iWidth, Int iHeight, RefPicList eRefPicList, TComYuv*& rpcYuvPred, Int iRefIdx)
{ 
  wpScalingParam  *pwp, *pwpTmp;
  if ( iRefIdx < 0 )
  {
    iRefIdx   = pcCU->getCUMvField( eRefPicList )->getRefIdx( uiPartAddr );
  }
  assert (iRefIdx >= 0);

  if ( eRefPicList == REF_PIC_LIST_0 )
  {
    getWpScaling(pcCU, iRefIdx, -1, pwp, pwpTmp);
  }
  else
  {
    getWpScaling(pcCU, -1, iRefIdx, pwpTmp, pwp);
  }
  addWeightUni( pcYuvSrc, uiPartAddr, iWidth, iHeight, pwp, rpcYuvPred );
}