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/** \file     Reshape.cpp
    \brief    common reshaper class
*/
#include "Reshape.h"
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <UnitTools.h>
 //! \ingroup CommonLib
 //! \{

 // ====================================================================================================================
 // Constructor / destructor / create / destroy
 // ====================================================================================================================

Reshape::Reshape()
: m_CTUFlag (false)
, m_recReshaped (false)
, m_reshape (true)
, m_chromaScale (1 << CSCALE_FP_PREC)
, m_vpduX (-1)
, m_vpduY (-1)
{
}

Reshape::~Reshape()
{
}

void  Reshape::createDec(int bitDepth)
{
  m_lumaBD = bitDepth;
  m_reshapeLUTSize = 1 << m_lumaBD;
  m_initCW = m_reshapeLUTSize / PIC_CODE_CW_BINS;
  if (m_fwdLUT.empty())
    m_fwdLUT.resize(m_reshapeLUTSize, 0);
  if (m_invLUT.empty())
    m_invLUT.resize(m_reshapeLUTSize, 0);
  if (m_binCW.empty())
    m_binCW.resize(PIC_CODE_CW_BINS, 0);
  if (m_inputPivot.empty())
    m_inputPivot.resize(PIC_CODE_CW_BINS + 1, 0);
  if (m_fwdScaleCoef.empty())
    m_fwdScaleCoef.resize(PIC_CODE_CW_BINS, 1 << FP_PREC);
  if (m_invScaleCoef.empty())
    m_invScaleCoef.resize(PIC_CODE_CW_BINS, 1 << FP_PREC);
  if (m_reshapePivot.empty())
    m_reshapePivot.resize(PIC_CODE_CW_BINS + 1, 0);
  if (m_chromaAdjHelpLUT.empty())
    m_chromaAdjHelpLUT.resize(PIC_CODE_CW_BINS, 1<<CSCALE_FP_PREC);
}

void  Reshape::destroy()
{
}



/** compute chroma residuce scale for TU
* \param average luma pred of TU
* \return chroma residue scale
*/
int  Reshape::calculateChromaAdj(Pel avgLuma)
{
  int iAdj = m_chromaAdjHelpLUT[getPWLIdxInv(avgLuma)];
  return(iAdj);
}

/** compute chroma residuce scale for TU
* \param average luma pred of TU
* \return chroma residue scale
*/
int  Reshape::calculateChromaAdjVpduNei(TransformUnit &tu, const CompArea &areaY)
{
  CodingStructure &cs = *tu.cs;
  int xPos = areaY.lumaPos().x;
  int yPos = areaY.lumaPos().y;
  int ctuSize = cs.sps->getCTUSize();
  int numNeighbor = std::min(64, ctuSize);
  int numNeighborLog = floorLog2(numNeighbor);
  if (ctuSize == 128)
  {
    xPos = xPos / 64 * 64;
    yPos = yPos / 64 * 64;
  }
  else
  {
    xPos = xPos / ctuSize * ctuSize;
    yPos = yPos / ctuSize * ctuSize;
  }

  if (isVPDUprocessed(xPos, yPos) && !cs.pcv->isEncoder)
  {
    return getChromaScale();
  }
  else
  {
    setVPDULoc(xPos, yPos);
    Position topLeft(xPos, yPos);
    CodingUnit *topLeftLuma;
    const CodingUnit *cuAbove, *cuLeft;
    if (CS::isDualITree(cs) && cs.slice->getSliceType() == I_SLICE)
    {
      topLeftLuma = tu.cs->picture->cs->getCU(topLeft, CHANNEL_TYPE_LUMA);
      cuAbove = cs.picture->cs->getCURestricted(topLeftLuma->lumaPos().offset(0, -1), *topLeftLuma, CHANNEL_TYPE_LUMA);
      cuLeft  = cs.picture->cs->getCURestricted(topLeftLuma->lumaPos().offset(-1, 0), *topLeftLuma, CHANNEL_TYPE_LUMA);
    }
    else
    {
      topLeftLuma = cs.getCU(topLeft, CHANNEL_TYPE_LUMA);
      cuAbove = cs.getCURestricted(topLeftLuma->lumaPos().offset(0, -1), *topLeftLuma, CHANNEL_TYPE_LUMA);
      cuLeft  = cs.getCURestricted(topLeftLuma->lumaPos().offset(-1, 0), *topLeftLuma, CHANNEL_TYPE_LUMA);
    }

    xPos = topLeftLuma->lumaPos().x;
    yPos = topLeftLuma->lumaPos().y;

    CompArea lumaArea = CompArea(COMPONENT_Y, tu.chromaFormat, topLeftLuma->lumaPos(), topLeftLuma->lumaSize(), true);
    PelBuf piRecoY = cs.picture->getRecoBuf(lumaArea);
    int strideY = piRecoY.stride;
    int chromaScale = (1 << CSCALE_FP_PREC);
    int lumaValue = -1;

    Pel* recSrc0 = piRecoY.bufAt(0, 0);
    const uint32_t picH = tu.cs->picture->lheight();
    const uint32_t picW = tu.cs->picture->lwidth();
    const Pel   valueDC = 1 << (tu.cs->sps->getBitDepth(CHANNEL_TYPE_LUMA) - 1);
    int32_t recLuma = 0;
    int pelnum = 0;
    if (cuLeft != nullptr)
    {
      for (int i = 0; i < numNeighbor; i++)
      {
        int k = (yPos + i) >= picH ? (picH - yPos - 1) : i;
        recLuma += recSrc0[-1 + k * strideY];
        pelnum++;
      }
    }
    if (cuAbove != nullptr)
    {
      for (int i = 0; i < numNeighbor; i++)
      {
        int k = (xPos + i) >= picW ? (picW - xPos - 1) : i;
        recLuma += recSrc0[-strideY + k];
        pelnum++;
      }
    }
    if (pelnum == numNeighbor)
    {
      lumaValue = (recLuma + (1 << (numNeighborLog - 1))) >> numNeighborLog;
    }
    else if (pelnum == (numNeighbor << 1))
    {
      lumaValue = (recLuma + (1 << numNeighborLog)) >> (numNeighborLog + 1);
    }
    else
    {
      CHECK(pelnum != 0, "");
      lumaValue = valueDC;
    }
    chromaScale = calculateChromaAdj(lumaValue);
    setChromaScale(chromaScale);
    return(chromaScale);
  }
}
/** find inx of PWL for inverse mapping
* \param average luma pred of TU
* \return idx of PWL for inverse mapping
*/
int Reshape::getPWLIdxInv(int lumaVal)
{
  int idxS = 0;
  for (idxS = m_sliceReshapeInfo.reshaperModelMinBinIdx; (idxS <= m_sliceReshapeInfo.reshaperModelMaxBinIdx); idxS++)
  {
    if (lumaVal < m_reshapePivot[idxS + 1])     break;
  }
  return std::min(idxS, PIC_CODE_CW_BINS-1);
}

/**
-copy Slice reshaper info structure
\param   tInfo describing the target Slice reshaper info structure
\param   sInfo describing the source Slice reshaper info structure
*/
void Reshape::copySliceReshaperInfo(SliceReshapeInfo& tInfo, SliceReshapeInfo& sInfo)
{
  tInfo.sliceReshaperModelPresentFlag = sInfo.sliceReshaperModelPresentFlag;
  if (sInfo.sliceReshaperModelPresentFlag)
  {
    tInfo.reshaperModelMaxBinIdx = sInfo.reshaperModelMaxBinIdx;
    tInfo.reshaperModelMinBinIdx = sInfo.reshaperModelMinBinIdx;
    memcpy(tInfo.reshaperModelBinCWDelta, sInfo.reshaperModelBinCWDelta, sizeof(int)*(PIC_CODE_CW_BINS));
    tInfo.maxNbitsNeededDeltaCW = sInfo.maxNbitsNeededDeltaCW;
    tInfo.chrResScalingOffset = sInfo.chrResScalingOffset;
  }
  tInfo.sliceReshaperEnableFlag = sInfo.sliceReshaperEnableFlag;
  if (sInfo.sliceReshaperEnableFlag)
    tInfo.enableChromaAdj = sInfo.enableChromaAdj;
  else
    tInfo.enableChromaAdj = 0;
}

/** Construct reshaper from syntax
* \param void
* \return void
*/
void Reshape::constructReshaper()
{
  int pwlFwdLUTsize = PIC_CODE_CW_BINS;
  int pwlFwdBinLen = m_reshapeLUTSize / PIC_CODE_CW_BINS;

  for (int i = 0; i < m_sliceReshapeInfo.reshaperModelMinBinIdx; i++)
    m_binCW[i] = 0;
  for (int i = m_sliceReshapeInfo.reshaperModelMaxBinIdx + 1; i < PIC_CODE_CW_BINS; i++)
    m_binCW[i] = 0;
  for (int i = m_sliceReshapeInfo.reshaperModelMinBinIdx; i <= m_sliceReshapeInfo.reshaperModelMaxBinIdx; i++)
    m_binCW[i] = (uint16_t)(m_sliceReshapeInfo.reshaperModelBinCWDelta[i] + (int)m_initCW);

  for (int i = 0; i < pwlFwdLUTsize; i++)
  {
    m_reshapePivot[i + 1] = m_reshapePivot[i] + m_binCW[i];
    m_inputPivot[i + 1] = m_inputPivot[i] + m_initCW;
    m_fwdScaleCoef[i] = ((int32_t)m_binCW[i] * (1 << FP_PREC) + (1 << (floorLog2(pwlFwdBinLen) - 1))) >> floorLog2(pwlFwdBinLen);
    if (m_binCW[i] == 0)
    {
      m_invScaleCoef[i] = 0;
      m_chromaAdjHelpLUT[i] = 1 << CSCALE_FP_PREC;
    }
    else
    {
      m_invScaleCoef[i] = (int32_t)(m_initCW * (1 << FP_PREC) / m_binCW[i]);
      m_chromaAdjHelpLUT[i] = (int32_t)(m_initCW * (1 << FP_PREC) / ( m_binCW[i] + m_sliceReshapeInfo.chrResScalingOffset ) );
    }
  }
  for (int lumaSample = 0; lumaSample < m_reshapeLUTSize; lumaSample++)
  {
    int idxY = lumaSample / m_initCW;
    int tempVal = m_reshapePivot[idxY] + ((m_fwdScaleCoef[idxY] * (lumaSample - m_inputPivot[idxY]) + (1 << (FP_PREC - 1))) >> FP_PREC);
    m_fwdLUT[lumaSample] = Clip3((Pel)0, (Pel)((1 << m_lumaBD) - 1), (Pel)(tempVal));

    int idxYInv = getPWLIdxInv(lumaSample);
    int invSample = m_inputPivot[idxYInv] + ((m_invScaleCoef[idxYInv] * (lumaSample - m_reshapePivot[idxYInv]) + (1 << (FP_PREC - 1))) >> FP_PREC);
    m_invLUT[lumaSample] = Clip3((Pel)0, (Pel)((1 << m_lumaBD) - 1), (Pel)(invSample));
  }
}



//
//! \}
