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/** \file     RdCostWeightPrediction.cpp
    \brief    RD cost computation class with Weighted-Prediction
*/

#include "RdCostWeightPrediction.h"

#include "RdCost.h"

#include <math.h>

static Distortion xCalcHADs2x2w(const WPScalingParam &wpCur, const Pel *piOrg, const Pel *piCurr, ptrdiff_t strideOrg,
                                ptrdiff_t strideCur, int step);
static Distortion xCalcHADs4x4w(const WPScalingParam &wpCur, const Pel *piOrg, const Pel *piCurr, ptrdiff_t strideOrg,
                                ptrdiff_t strideCur, int step);
static Distortion xCalcHADs8x8w(const WPScalingParam &wpCur, const Pel *piOrg, const Pel *piCurr, ptrdiff_t strideOrg,
                                ptrdiff_t strideCur, int step);

// --------------------------------------------------------------------------------------------------------------------
// SAD
// --------------------------------------------------------------------------------------------------------------------
/** get weighted SAD cost
 * \param pcDtParam
 * \returns Distortion
 */
Distortion RdCostWeightPrediction::xGetSADw( const DistParam &rcDtParam )
{
  const Pel            *piOrg      = rcDtParam.org.buf;
  const Pel            *piCur      = rcDtParam.cur.buf;
  const int             cols       = rcDtParam.org.width;
  const ptrdiff_t       strideCur  = rcDtParam.cur.stride;
  const ptrdiff_t       strideOrg  = rcDtParam.org.stride;
  const ComponentID     compID     = rcDtParam.compID;

  CHECK( compID >= MAX_NUM_COMPONENT, "Invalid component" );

  const WPScalingParam &wpCur      = rcDtParam.wpCur[compID];

  const int             w0         = wpCur.w;
  const int             offset     = wpCur.offset;
  const int             shift      = wpCur.shift;
  const int             round      = wpCur.round;
  const int distortionShift = DISTORTION_PRECISION_ADJUSTMENT(rcDtParam.bitDepth);

  Distortion sum = 0;

  ClpRng clpRng; // this just affects the cost
  clpRng.min = 0;
  clpRng.max = (1 << rcDtParam.bitDepth) - 1;

  // Default weight
  if (w0 == 1 << shift)
  {
    // no offset
    if (offset == 0)
    {
      for (int rows = rcDtParam.org.height; rows != 0; rows--)
      {
        for (int n = 0; n < cols; n++)
        {
          sum += abs(piOrg[n] - piCur[n]);
        }
        if (rcDtParam.maximumDistortionForEarlyExit < (sum >> distortionShift))
        {
          return sum >> distortionShift;
        }
        piOrg += strideOrg;
        piCur += strideCur;
      }
    }
    else
    {
      // Lets not clip for the bipredictive case since clipping should be done after
      // combining both elements. Unfortunately the code uses the suboptimal "subtraction"
      // method, which is faster but introduces the clipping issue (therefore Bipred is suboptimal).
      if (rcDtParam.isBiPred)
      {
        for (int rows = rcDtParam.org.height; rows != 0; rows--)
        {
          for (int n = 0; n < cols; n++)
          {
            sum += abs(piOrg[n] - (piCur[n] + offset));
          }
          if (rcDtParam.maximumDistortionForEarlyExit < (sum >> distortionShift))
          {
            return sum >> distortionShift;
          }

          piOrg += strideOrg;
          piCur += strideCur;
        }
      }
      else
      {
        for (int rows = rcDtParam.org.height; rows != 0; rows--)
        {
          for (int n = 0; n < cols; n++)
          {
            const Pel pred = ClipPel( piCur[n] + offset, clpRng);

            sum += abs(piOrg[n] - pred);
          }
          if (rcDtParam.maximumDistortionForEarlyExit < (sum >> distortionShift))
          {
            return sum >> distortionShift;
          }
          piOrg += strideOrg;
          piCur += strideCur;
        }
      }
    }
  }
  else
  {
    // Lets not clip for the bipredictive case since clipping should be done after
    // combining both elements. Unfortunately the code uses the suboptimal "subtraction"
    // method, which is faster but introduces the clipping issue (therefore Bipred is suboptimal).
    if (rcDtParam.isBiPred)
    {
      for (int rows = rcDtParam.org.height; rows != 0; rows--)
      {
        for (int n = 0; n < cols; n++)
        {
          const Pel pred = ( (w0*piCur[n] + round) >> shift ) + offset ;
          sum += abs(piOrg[n] - pred);
        }
        if (rcDtParam.maximumDistortionForEarlyExit < (sum >> distortionShift))
        {
          return sum >> distortionShift;
        }

        piOrg += strideOrg;
        piCur += strideCur;
      }
    }
    else
    {
      if (offset == 0)
      {
        for (int rows = rcDtParam.org.height; rows != 0; rows--)
        {
          for (int n = 0; n < cols; n++)
          {
            const Pel pred = ClipPel( (w0*piCur[n] + round) >> shift, clpRng);

            sum += abs(piOrg[n] - pred);
          }
          if (rcDtParam.maximumDistortionForEarlyExit < (sum >> distortionShift))
          {
            return sum >> distortionShift;
          }
          piOrg += strideOrg;
          piCur += strideCur;
        }
      }
      else
      {
        for (int rows = rcDtParam.org.height; rows != 0; rows--)
        {
          for (int n = 0; n < cols; n++)
          {
            const Pel pred = ClipPel(((w0*piCur[n] + round) >> shift ) + offset,  clpRng) ;

            sum += abs(piOrg[n] - pred);
          }
          if (rcDtParam.maximumDistortionForEarlyExit < (sum >> distortionShift))
          {
            return sum >> distortionShift;
          }
          piOrg += strideOrg;
          piCur += strideCur;
        }
      }
    }
  }
  //rcDtParam.compIdx = MAX_NUM_COMPONENT;  // reset for DEBUG (assert test)

  return sum >> distortionShift;
}


// --------------------------------------------------------------------------------------------------------------------
// SSE
// --------------------------------------------------------------------------------------------------------------------
/** get weighted SSD cost
 * \param pcDtParam
 * \returns Distortion
 */
Distortion RdCostWeightPrediction::xGetSSEw( const DistParam &rcDtParam )
{
  const Pel            *piOrg      = rcDtParam.org.buf;
  const Pel            *piCur      = rcDtParam.cur.buf;
  const int             cols       = rcDtParam.org.width;
  const ptrdiff_t       strideCur  = rcDtParam.cur.stride;
  const ptrdiff_t       strideOrg  = rcDtParam.org.stride;
  const ComponentID     compID     = rcDtParam.compID;

  CHECK( rcDtParam.subShift != 0, "Subshift not supported" ); // NOTE: what is this protecting?
  CHECK( compID >= MAX_NUM_COMPONENT, "Invalid channel" );

  const WPScalingParam &wpCur           = rcDtParam.wpCur[compID];
  const int             w0              = wpCur.w;
  const int             offset          = wpCur.offset;
  const int             shift           = wpCur.shift;
  const int             round           = wpCur.round;
  const uint32_t distortionShift = DISTORTION_PRECISION_ADJUSTMENT(rcDtParam.bitDepth) << 1;

  Distortion sum = 0;

  if (rcDtParam.isBiPred)
  {
    for (int rows = rcDtParam.org.height; rows != 0; rows--)
    {
      for (int n = 0; n < cols; n++)
      {
        const Pel pred     = ( (w0*piCur[n] + round) >> shift ) + offset ;
        const Pel residual = piOrg[n] - pred;
        sum += ( Distortion(residual) * Distortion(residual) ) >> distortionShift;
      }
      piOrg += strideOrg;
      piCur += strideCur;
    }
  }
  else
  {
    ClpRng clpRng;  // this just affects the cost - fix this later
    clpRng.min = 0;
    clpRng.max = (1 << rcDtParam.bitDepth) - 1;

    for (int rows = rcDtParam.org.height; rows != 0; rows--)
    {
      for (int n = 0; n < cols; n++)
      {
        const Pel pred     = ClipPel(( (w0*piCur[n] + round) >> shift ) + offset, clpRng) ;
        const Pel residual = piOrg[n] - pred;
        sum += ( Distortion(residual) * Distortion(residual) ) >> distortionShift;
      }
      piOrg += strideOrg;
      piCur += strideCur;
    }
  }

  //rcDtParam.compIdx = MAX_NUM_COMPONENT; // reset for DEBUG (assert test)

  return sum;
}


// --------------------------------------------------------------------------------------------------------------------
// HADAMARD with step (used in fractional search)
// --------------------------------------------------------------------------------------------------------------------
//! get weighted Hadamard cost for 2x2 block
Distortion xCalcHADs2x2w(const WPScalingParam &wpCur, const Pel *piOrg, const Pel *piCur, ptrdiff_t strideOrg,
                         ptrdiff_t strideCur, int step)
{
  const int round  = wpCur.round;
  const int shift  = wpCur.shift;
  const int offset = wpCur.offset;
  const int w0     = wpCur.w;

  Distortion satd  = 0;
  TCoeff     diff[4];
  TCoeff     m[4];

  Pel   pred;

  pred    = ((w0 * piCur[0 * step] + round) >> shift) + offset;
  diff[0] = piOrg[0             ] - pred;
  pred    = ((w0 * piCur[1 * step] + round) >> shift) + offset;
  diff[1] = piOrg[1             ] - pred;
  pred    = ((w0 * piCur[0 * step + strideCur] + round) >> shift) + offset;
  diff[2] = piOrg[strideOrg] - pred;
  pred    = ((w0 * piCur[1 * step + strideCur] + round) >> shift) + offset;
  diff[3] = piOrg[strideOrg + 1] - pred;

  m[0] = diff[0] + diff[2];
  m[1] = diff[1] + diff[3];
  m[2] = diff[0] - diff[2];
  m[3] = diff[1] - diff[3];

  satd += abs(m[0] + m[1]);
  satd += abs(m[0] - m[1]);
  satd += abs(m[2] + m[3]);
  satd += abs(m[2] - m[3]);

  return satd;
}


//! get weighted Hadamard cost for 4x4 block
Distortion xCalcHADs4x4w(const WPScalingParam &wpCur, const Pel *piOrg, const Pel *piCur, ptrdiff_t strideOrg,
                         ptrdiff_t strideCur, int step)
{
  const int round  = wpCur.round;
  const int shift  = wpCur.shift;
  const int offset = wpCur.offset;
  const int w0     = wpCur.w;

  Distortion satd = 0;
  TCoeff     diff[16];
  TCoeff     m[16];
  TCoeff     d[16];


  for(int k = 0; k < 16; k+=4 )
  {
    Pel pred;
    pred      = ((w0 * piCur[0 * step] + round) >> shift) + offset;
    diff[k+0] = piOrg[0] - pred;
    pred      = ((w0 * piCur[1 * step] + round) >> shift) + offset;
    diff[k+1] = piOrg[1] - pred;
    pred      = ((w0 * piCur[2 * step] + round) >> shift) + offset;
    diff[k+2] = piOrg[2] - pred;
    pred      = ((w0 * piCur[3 * step] + round) >> shift) + offset;
    diff[k+3] = piOrg[3] - pred;

    piCur += strideCur;
    piOrg += strideOrg;
  }

  /*===== hadamard transform =====*/
  m[ 0] = diff[ 0] + diff[12];
  m[ 1] = diff[ 1] + diff[13];
  m[ 2] = diff[ 2] + diff[14];
  m[ 3] = diff[ 3] + diff[15];
  m[ 4] = diff[ 4] + diff[ 8];
  m[ 5] = diff[ 5] + diff[ 9];
  m[ 6] = diff[ 6] + diff[10];
  m[ 7] = diff[ 7] + diff[11];
  m[ 8] = diff[ 4] - diff[ 8];
  m[ 9] = diff[ 5] - diff[ 9];
  m[10] = diff[ 6] - diff[10];
  m[11] = diff[ 7] - diff[11];
  m[12] = diff[ 0] - diff[12];
  m[13] = diff[ 1] - diff[13];
  m[14] = diff[ 2] - diff[14];
  m[15] = diff[ 3] - diff[15];

  d[ 0] = m[ 0] + m[ 4];
  d[ 1] = m[ 1] + m[ 5];
  d[ 2] = m[ 2] + m[ 6];
  d[ 3] = m[ 3] + m[ 7];
  d[ 4] = m[ 8] + m[12];
  d[ 5] = m[ 9] + m[13];
  d[ 6] = m[10] + m[14];
  d[ 7] = m[11] + m[15];
  d[ 8] = m[ 0] - m[ 4];
  d[ 9] = m[ 1] - m[ 5];
  d[10] = m[ 2] - m[ 6];
  d[11] = m[ 3] - m[ 7];
  d[12] = m[12] - m[ 8];
  d[13] = m[13] - m[ 9];
  d[14] = m[14] - m[10];
  d[15] = m[15] - m[11];

  m[ 0] = d[ 0] + d[ 3];
  m[ 1] = d[ 1] + d[ 2];
  m[ 2] = d[ 1] - d[ 2];
  m[ 3] = d[ 0] - d[ 3];
  m[ 4] = d[ 4] + d[ 7];
  m[ 5] = d[ 5] + d[ 6];
  m[ 6] = d[ 5] - d[ 6];
  m[ 7] = d[ 4] - d[ 7];
  m[ 8] = d[ 8] + d[11];
  m[ 9] = d[ 9] + d[10];
  m[10] = d[ 9] - d[10];
  m[11] = d[ 8] - d[11];
  m[12] = d[12] + d[15];
  m[13] = d[13] + d[14];
  m[14] = d[13] - d[14];
  m[15] = d[12] - d[15];

  d[ 0] = m[ 0] + m[ 1];
  d[ 1] = m[ 0] - m[ 1];
  d[ 2] = m[ 2] + m[ 3];
  d[ 3] = m[ 3] - m[ 2];
  d[ 4] = m[ 4] + m[ 5];
  d[ 5] = m[ 4] - m[ 5];
  d[ 6] = m[ 6] + m[ 7];
  d[ 7] = m[ 7] - m[ 6];
  d[ 8] = m[ 8] + m[ 9];
  d[ 9] = m[ 8] - m[ 9];
  d[10] = m[10] + m[11];
  d[11] = m[11] - m[10];
  d[12] = m[12] + m[13];
  d[13] = m[12] - m[13];
  d[14] = m[14] + m[15];
  d[15] = m[15] - m[14];

  for (int k=0; k<16; ++k)
  {
    satd += abs(d[k]);
  }
  satd = ((satd+1)>>1);

  return satd;
}


//! get weighted Hadamard cost for 8x8 block
Distortion xCalcHADs8x8w(const WPScalingParam &wpCur, const Pel *piOrg, const Pel *piCur, ptrdiff_t strideOrg,
                         ptrdiff_t strideCur, int step)
{
  Distortion sad=0;
  TCoeff diff[64], m1[8][8], m2[8][8], m3[8][8];
  int        step2  = step << 1;
  int        step3  = step2 + step;
  int        step4  = step3 + step;
  int        step5  = step4 + step;
  int        step6  = step5 + step;
  int        step7  = step6 + step;
  const int round  = wpCur.round;
  const int shift  = wpCur.shift;
  const int offset = wpCur.offset;
  const int w0     = wpCur.w;

  Pel   pred;

  for(int k = 0; k < 64; k+=8 )
  {
    pred      = ( (w0*piCur[     0] + round) >> shift ) + offset ;
    diff[k+0] = piOrg[0] - pred;
    pred      = ((w0 * piCur[step] + round) >> shift) + offset;
    diff[k+1] = piOrg[1] - pred;
    pred      = ((w0 * piCur[step2] + round) >> shift) + offset;
    diff[k+2] = piOrg[2] - pred;
    pred      = ((w0 * piCur[step3] + round) >> shift) + offset;
    diff[k+3] = piOrg[3] - pred;
    pred      = ((w0 * piCur[step4] + round) >> shift) + offset;
    diff[k+4] = piOrg[4] - pred;
    pred      = ((w0 * piCur[step5] + round) >> shift) + offset;
    diff[k+5] = piOrg[5] - pred;
    pred      = ((w0 * piCur[step6] + round) >> shift) + offset;
    diff[k+6] = piOrg[6] - pred;
    pred      = ((w0 * piCur[step7] + round) >> shift) + offset;
    diff[k+7] = piOrg[7] - pred;

    piCur += strideCur;
    piOrg += strideOrg;
  }

  //horizontal
  for (int j=0; j < 8; j++)
  {
    const int jj = j << 3;
    m2[j][0] = diff[jj  ] + diff[jj+4];
    m2[j][1] = diff[jj+1] + diff[jj+5];
    m2[j][2] = diff[jj+2] + diff[jj+6];
    m2[j][3] = diff[jj+3] + diff[jj+7];
    m2[j][4] = diff[jj  ] - diff[jj+4];
    m2[j][5] = diff[jj+1] - diff[jj+5];
    m2[j][6] = diff[jj+2] - diff[jj+6];
    m2[j][7] = diff[jj+3] - diff[jj+7];

    m1[j][0] = m2[j][0] + m2[j][2];
    m1[j][1] = m2[j][1] + m2[j][3];
    m1[j][2] = m2[j][0] - m2[j][2];
    m1[j][3] = m2[j][1] - m2[j][3];
    m1[j][4] = m2[j][4] + m2[j][6];
    m1[j][5] = m2[j][5] + m2[j][7];
    m1[j][6] = m2[j][4] - m2[j][6];
    m1[j][7] = m2[j][5] - m2[j][7];

    m2[j][0] = m1[j][0] + m1[j][1];
    m2[j][1] = m1[j][0] - m1[j][1];
    m2[j][2] = m1[j][2] + m1[j][3];
    m2[j][3] = m1[j][2] - m1[j][3];
    m2[j][4] = m1[j][4] + m1[j][5];
    m2[j][5] = m1[j][4] - m1[j][5];
    m2[j][6] = m1[j][6] + m1[j][7];
    m2[j][7] = m1[j][6] - m1[j][7];
  }

  //vertical
  for (int i=0; i < 8; i++)
  {
    m3[0][i] = m2[0][i] + m2[4][i];
    m3[1][i] = m2[1][i] + m2[5][i];
    m3[2][i] = m2[2][i] + m2[6][i];
    m3[3][i] = m2[3][i] + m2[7][i];
    m3[4][i] = m2[0][i] - m2[4][i];
    m3[5][i] = m2[1][i] - m2[5][i];
    m3[6][i] = m2[2][i] - m2[6][i];
    m3[7][i] = m2[3][i] - m2[7][i];

    m1[0][i] = m3[0][i] + m3[2][i];
    m1[1][i] = m3[1][i] + m3[3][i];
    m1[2][i] = m3[0][i] - m3[2][i];
    m1[3][i] = m3[1][i] - m3[3][i];
    m1[4][i] = m3[4][i] + m3[6][i];
    m1[5][i] = m3[5][i] + m3[7][i];
    m1[6][i] = m3[4][i] - m3[6][i];
    m1[7][i] = m3[5][i] - m3[7][i];

    m2[0][i] = m1[0][i] + m1[1][i];
    m2[1][i] = m1[0][i] - m1[1][i];
    m2[2][i] = m1[2][i] + m1[3][i];
    m2[3][i] = m1[2][i] - m1[3][i];
    m2[4][i] = m1[4][i] + m1[5][i];
    m2[5][i] = m1[4][i] - m1[5][i];
    m2[6][i] = m1[6][i] + m1[7][i];
    m2[7][i] = m1[6][i] - m1[7][i];
  }

  for (int j=0; j < 8; j++)
  {
    for (int i=0; i < 8; i++)
    {
      sad += (abs(m2[j][i]));
    }
  }

  sad=((sad+2)>>2);

  return sad;
}


//! get weighted Hadamard cost
Distortion RdCostWeightPrediction::xGetHADsw( const DistParam &rcDtParam )
{
  const Pel        *piOrg      = rcDtParam.org.buf;
  const Pel        *piCur      = rcDtParam.cur.buf;
  const int         rows       = rcDtParam.org.height;
  const int         cols       = rcDtParam.org.width;
  const ptrdiff_t   strideCur  = rcDtParam.cur.stride;
  const ptrdiff_t   strideOrg  = rcDtParam.org.stride;
  const int         step       = rcDtParam.step;
  const ComponentID compIdx    = rcDtParam.compID;
  CHECK(compIdx>=MAX_NUM_COMPONENT, "Invalid component");
  const WPScalingParam &wpCur  = rcDtParam.wpCur[compIdx];

  Distortion sum = 0;

  if ((rows % 8 == 0) && (cols % 8 == 0))
  {
    const ptrdiff_t offsetOrg = strideOrg << 3;
    const ptrdiff_t offsetCur = strideCur << 3;
    for (int y = 0; y < rows; y += 8)
    {
      for (int x = 0; x < cols; x += 8)
      {
        sum += xCalcHADs8x8w(wpCur, &piOrg[x], &piCur[x * step], strideOrg, strideCur, step);
      }
      piOrg += offsetOrg;
      piCur += offsetCur;
    }
  }
  else if ((rows % 4 == 0) && (cols % 4 == 0))
  {
    const ptrdiff_t offsetOrg = strideOrg << 2;
    const ptrdiff_t offsetCur = strideCur << 2;

    for (int y = 0; y < rows; y += 4)
    {
      for (int x = 0; x < cols; x += 4)
      {
        sum += xCalcHADs4x4w(wpCur, &piOrg[x], &piCur[x * step], strideOrg, strideCur, step);
      }
      piOrg += offsetOrg;
      piCur += offsetCur;
    }
  }
  else
  {
    for (int y = 0; y < rows; y += 2)
    {
      for (int x = 0; x < cols; x += 2)
      {
        sum += xCalcHADs2x2w(wpCur, &piOrg[x], &piCur[x * step], strideOrg, strideCur, step);
      }
      piOrg += strideOrg;
      piCur += strideCur;
    }
  }

  return sum >> DISTORTION_PRECISION_ADJUSTMENT(rcDtParam.bitDepth);
}