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/** \file     WeightPrediction.h

    \brief    weighting prediction class (header)

*/

// Include files

#include "CommonDef.h"

#include "Unit.h"

#include "InterpolationFilter.h"

#include "WeightPrediction.h"

#include "CodingStructure.h"

namespace vvdec

{

// ====================================================================================================================

// Class definition

// ====================================================================================================================

WeightPrediction::WeightPrediction()

{

}

void  WeightPrediction::getWpScaling(const Slice                *pcSlice,

                                     const int                  &iRefIdx0,

                                     const int                  &iRefIdx1,

                                           WPScalingParam       *wp0,

                                           WPScalingParam       *wp1)

{

  CHECK(iRefIdx0 < 0 && iRefIdx1 < 0, "Both picture reference list indizes smaller than '0'");

  const bool wpBiPred        = pcSlice->getPPS()->getWPBiPred();

  const bool bBiPred         = (iRefIdx0 >= 0 && iRefIdx1 >= 0);

  const bool bUniPred        = !bBiPred;

  const WPScalingParam* wp0org;

  const WPScalingParam* wp1org;

  if (bUniPred || wpBiPred)

  {

    // explicit --------------------

    if (iRefIdx0 >= 0)

    {

      pcSlice->getWpScaling(REF_PIC_LIST_0, iRefIdx0, wp0org);

    }

    if (iRefIdx1 >= 0)

    {

      pcSlice->getWpScaling(REF_PIC_LIST_1, iRefIdx1, wp1org);

    }

  }

  else

  {

    THROW_RECOVERABLE( "Unsupported WP configuration" );

  }

  const uint32_t numValidComponent = getNumberValidComponents(pcSlice->getSPS()->getChromaFormatIdc());

  if( iRefIdx0 < 0 )

  {

    for( int yuv = 0; yuv < numValidComponent; yuv++ )

    {

      wp0[yuv].bPresentFlag = false;

    }

  }

  if( iRefIdx1 < 0 )

  {

    for( int yuv = 0; yuv < numValidComponent; yuv++ )

    {

      wp1[yuv].bPresentFlag = false;

    }

  }

  const bool bUseHighPrecisionPredictionWeighting = false; // pcSlice->getSPS()->getSpsRangeExtension().getHighPrecisionOffsetsEnabledFlag();

  if (bBiPred)

  {

    // Bi-predictive case

    for (int yuv = 0; yuv < numValidComponent; yuv++)

    {

      const int bitDepth = pcSlice->getSPS()->getBitDepth();

      const int offsetScalingFactor = bUseHighPrecisionPredictionWeighting ? 1 : (1 << (bitDepth - 8));

      wp0[yuv] = wp0org[yuv];

      wp1[yuv] = wp1org[yuv];

      wp0[yuv].w = wp0org[yuv].iWeight;

      wp1[yuv].w = wp1org[yuv].iWeight;

      wp0[yuv].o = wp0org[yuv].iOffset * offsetScalingFactor;

      wp1[yuv].o = wp1org[yuv].iOffset * offsetScalingFactor;

      wp0[yuv].offset = wp1[yuv].offset = wp0[yuv].o + wp1[yuv].o;

      wp0[yuv].shift  = wp1[yuv].shift  = wp0org[yuv].uiLog2WeightDenom + 1;

      wp0[yuv].round  = wp1[yuv].round  = ( 1 << wp0org[yuv].uiLog2WeightDenom );

    }

  }

  else

  {

    // UniPred

    const WPScalingParam* const pwporg = ( iRefIdx0 >= 0 ) ? wp0org : wp1org;

          WPScalingParam* const pwp    = ( iRefIdx0 >= 0 ) ? wp0 : wp1;

    for (int yuv = 0; yuv < numValidComponent; yuv++)

    {

      const int bitDepth            = pcSlice->getSPS()->getBitDepth();

      const int offsetScalingFactor = bUseHighPrecisionPredictionWeighting ? 1 : (1 << (bitDepth - 8));

      pwp[yuv]        = pwporg[yuv];

      pwp[yuv].w      = pwporg[yuv].iWeight;

      pwp[yuv].offset = pwporg[yuv].iOffset * offsetScalingFactor;

      pwp[yuv].shift  = pwporg[yuv].uiLog2WeightDenom;

      pwp[yuv].round  = ( pwporg[yuv].uiLog2WeightDenom >= 1 ) ? ( 1 << ( pwporg[yuv].uiLog2WeightDenom - 1 ) ) : ( 0 );

    }

  }

}

static inline Pel weightBidir( int w0, Pel P0, int w1, Pel P1, int round, int shift, int offset, const ClpRng& clpRng )

{

  return ClipPel( ( ( w0*( P0 + IF_INTERNAL_OFFS ) + w1 * ( P1 + IF_INTERNAL_OFFS ) + round + ( offset * ( 1 << ( shift - 1 ) ) ) ) >> shift ), clpRng );

}

void WeightPrediction::addWeightBi(const PelUnitBuf           &pcYuvSrc0,

                                   const PelUnitBuf           &pcYuvSrc1,

                                   const ClpRngs              &clpRngs,

                                   const WPScalingParam *const wp0,

                                   const WPScalingParam *const wp1,

                                         PelUnitBuf           &rpcYuvDst

                                  )

{

  const uint32_t numValidComponent = (const uint32_t)pcYuvSrc0.bufs.size();

  for (int componentIndex = 0; componentIndex < numValidComponent; componentIndex++)

  {

    const ComponentID compID = ComponentID(componentIndex);

    const Pel* pSrc0 = pcYuvSrc0.bufs[compID].buf;

    const Pel* pSrc1 = pcYuvSrc1.bufs[compID].buf;

          Pel* pDst  = rpcYuvDst.bufs[compID].buf;

    const ptrdiff_t iSrc0Stride = pcYuvSrc0.bufs[compID].stride;

    const ptrdiff_t iSrc1Stride = pcYuvSrc1.bufs[compID].stride;

    const ptrdiff_t iDstStride  = rpcYuvDst.bufs[compID].stride;

    const ClpRng& clpRng = clpRngs;

    const int  w0       = wp0[compID].w;

    const int  offset   = wp0[compID].offset;

    const int  clipBD   = clpRng.bd;

    const int  shiftNum = std::max<int>(2, (IF_INTERNAL_PREC - clipBD));

    const int  shift    = wp0[compID].shift + shiftNum;

    const int  round    = 1 << shift >> 1;

    const int  w1       = wp1[compID].w;

    const int  iHeight  = rpcYuvDst.bufs[compID].height;

    const int  iWidth   = rpcYuvDst.bufs[compID].width;

    const int  applyOffset = round + ( offset * ( 1 << ( shift - 1 ) ) ) + ( w0 + w1 ) * IF_INTERNAL_OFFS;

    if( ( iWidth & 7 ) == 0 )

    {

      g_pelBufOP.wghtAvg8( pSrc0, iSrc0Stride, pSrc1, iSrc1Stride, pDst, iDstStride, iWidth, iHeight, shift, applyOffset, w0, w1, clpRngs );

    }

    else if( ( iWidth & 3 ) == 0 )

      g_pelBufOP.wghtAvg4( pSrc0, iSrc0Stride, pSrc1, iSrc1Stride, pDst, iDstStride, iWidth, iHeight, shift, applyOffset, w0, w1, clpRngs );

    else

    {

      CHECK( iWidth != 2, "Should only happen for width '2'" );

      for (int y = iHeight - 1; y >= 0; y--)

      {

        pDst[0] = weightBidir(w0, pSrc0[0], w1, pSrc1[0], round, shift, offset, clpRng );;

        pDst[1] = weightBidir(w0, pSrc0[1], w1, pSrc1[1], round, shift, offset, clpRng );;

        pSrc0 += iSrc0Stride;

        pSrc1 += iSrc1Stride;

        pDst += iDstStride;

      } // y loop

    }

  } // compID loop

}

static inline Pel weightUnidir( int w0, Pel P0, int round, int shift, int offset, const ClpRng& clpRng )

{

  return ClipPel( ( ( w0*( P0 + IF_INTERNAL_OFFS ) + round ) >> shift ) + offset, clpRng );

}

static inline Pel noWeightUnidir( Pel P0, int round, int shift, int offset, const ClpRng& clpRng )

{

  return ClipPel( ( ( ( P0 + IF_INTERNAL_OFFS ) + round ) >> shift ) + offset, clpRng );

}

static inline Pel noWeightOffsetUnidir( Pel P0, int round, int shift, const ClpRng& clpRng )

{

  return ClipPel( ( ( ( P0 + IF_INTERNAL_OFFS ) + round ) >> shift ), clpRng );

}

void  WeightPrediction::addWeightUni(const PelUnitBuf           &pcYuvSrc0,

                                     const ClpRngs              &clpRngs,

                                     const WPScalingParam *const wp0,

                                           PelUnitBuf           &rpcYuvDst

                                    )

{

  const uint32_t numValidComponent = (const uint32_t)pcYuvSrc0.bufs.size();

  for (int componentIndex = 0; componentIndex < numValidComponent; componentIndex++)

  {

    const ComponentID compID = ComponentID(componentIndex);

    const Pel* pSrc0 = pcYuvSrc0.bufs[compID].buf;

          Pel* pDst  = rpcYuvDst.bufs[compID].buf;

    // Luma : --------------------------------------------

    const ClpRng& clpRng    = clpRngs;

    const int  w0           = wp0[compID].w;

    const int  offset       = wp0[compID].offset;

    const int  clipBD       = clpRng.bd;

    const int  shiftNum     = std::max<int>(2, (IF_INTERNAL_PREC - clipBD));

    const int  shift        = wp0[compID].shift + shiftNum;

    const ptrdiff_t iSrc0Stride  = pcYuvSrc0.bufs[compID].stride;

    const ptrdiff_t iDstStride   = rpcYuvDst.bufs[compID].stride;

    const int  iHeight      = rpcYuvDst.bufs[compID].height;

    const int  iWidth       = rpcYuvDst.bufs[compID].width;

    if (w0 != 1 << wp0[compID].shift)

    {

      const int  round = (shift > 0) ? (1 << (shift - 1)) : 0;

      for (int y = iHeight - 1; y >= 0; y--)

      {

        int x = iWidth - 1;

        for (; x >= 3; )

        {

          pDst[x] = weightUnidir(w0, pSrc0[x], round, shift, offset, clpRng); x--;

          pDst[x] = weightUnidir(w0, pSrc0[x], round, shift, offset, clpRng); x--;

          pDst[x] = weightUnidir(w0, pSrc0[x], round, shift, offset, clpRng); x--;

          pDst[x] = weightUnidir(w0, pSrc0[x], round, shift, offset, clpRng); x--;

        }

        for (; x >= 0; x--)

        {

          pDst[x] = weightUnidir(w0, pSrc0[x], round, shift, offset, clpRng);

        }

        pSrc0 += iSrc0Stride;

        pDst += iDstStride;

      }

    }

    else

    {

      const int  round = (shiftNum > 0) ? (1 << (shiftNum - 1)) : 0;

      if (offset == 0)

      {

        for (int y = iHeight - 1; y >= 0; y--)

        {

          int x = iWidth - 1;

          for (; x >= 3; )

          {

            pDst[x] = noWeightOffsetUnidir(pSrc0[x], round, shiftNum, clpRng); x--;

            pDst[x] = noWeightOffsetUnidir(pSrc0[x], round, shiftNum, clpRng); x--;

            pDst[x] = noWeightOffsetUnidir(pSrc0[x], round, shiftNum, clpRng); x--;

            pDst[x] = noWeightOffsetUnidir(pSrc0[x], round, shiftNum, clpRng); x--;

          }

          for (; x >= 0; x--)

          {

            pDst[x] = noWeightOffsetUnidir(pSrc0[x], round, shiftNum, clpRng);

          }

          pSrc0 += iSrc0Stride;

          pDst += iDstStride;

        }

      }

      else

      {

        for (int y = iHeight - 1; y >= 0; y--)

        {

          int x = iWidth - 1;

          for (; x >= 3; )

          {

            pDst[x] = noWeightUnidir(pSrc0[x], round, shiftNum, offset, clpRng); x--;

            pDst[x] = noWeightUnidir(pSrc0[x], round, shiftNum, offset, clpRng); x--;

            pDst[x] = noWeightUnidir(pSrc0[x], round, shiftNum, offset, clpRng); x--;

            pDst[x] = noWeightUnidir(pSrc0[x], round, shiftNum, offset, clpRng); x--;

          }

          for (; x >= 0; x--)

          {

            pDst[x] = noWeightUnidir(pSrc0[x], round, shiftNum, offset, clpRng);

          }

          pSrc0 += iSrc0Stride;

          pDst += iDstStride;

        }

      }

    }

  }

}

void  WeightPrediction::xWeightedPredictionUni(const CodingUnit       &cu,

                                               const PelUnitBuf           &pcYuvSrc,

                                               const RefPicList           &eRefPicList,

                                                     PelUnitBuf           &pcYuvPred,

                                               const int                   iRefIdx_input/* = -1*/

                                              )

{

  WPScalingParam  pwp[MAX_NUM_COMPONENT], pwpTmp[MAX_NUM_COMPONENT];

  int iRefIdx = iRefIdx_input;

  if (iRefIdx < 0)

  {

    iRefIdx = cu.refIdx[eRefPicList];

  }

  CHECK(iRefIdx < 0, "Negative reference picture list index");

  if (eRefPicList == REF_PIC_LIST_0)

  {

    getWpScaling(cu.slice, iRefIdx, -1, pwp, pwpTmp);

  }

  else

  {

    getWpScaling(cu.slice, -1, iRefIdx, pwpTmp, pwp);

  }

  addWeightUni(pcYuvSrc, cu.slice->clpRngs(), pwp, pcYuvPred);

}

void  WeightPrediction::xWeightedPredictionBi(const CodingUnit       &cu,

                                              const PelUnitBuf           &pcYuvSrc0,

                                              const PelUnitBuf           &pcYuvSrc1,

                                                    PelUnitBuf           &rpcYuvDst

                                             )

{

  const int iRefIdx0 = cu.refIdx[0];

  const int iRefIdx1 = cu.refIdx[1];

  WPScalingParam  pwp0[MAX_NUM_COMPONENT];

  WPScalingParam  pwp1[MAX_NUM_COMPONENT];

  CHECK( !cu.pps->getWPBiPred(), "Weighted Bi-prediction disabled" );

  getWpScaling(cu.slice, iRefIdx0, iRefIdx1, pwp0, pwp1);

  if (iRefIdx0 >= 0 && iRefIdx1 >= 0)

  {

    addWeightBi(pcYuvSrc0, pcYuvSrc1, cu.slice->clpRngs(), pwp0, pwp1, rpcYuvDst);

  }

  else if (iRefIdx0 >= 0 && iRefIdx1 < 0)

  {

    addWeightUni(pcYuvSrc0, cu.slice->clpRngs(), pwp0, rpcYuvDst);

  }

  else if (iRefIdx0 < 0 && iRefIdx1 >= 0)

  {

    addWeightUni(pcYuvSrc1, cu.slice->clpRngs(), pwp1, rpcYuvDst);

  }

  else

  {

    THROW_RECOVERABLE( "Both reference picture list indices are negative" );

  }

}

}