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/** \file     EncTemporalFilter.cpp
\brief    EncTemporalFilter class
*/

#include "EncTemporalFilter.h"
#include <math.h>


// ====================================================================================================================
// Constructor / destructor / initialization / destroy
// ====================================================================================================================

const int EncTemporalFilter::m_range = 2;
const double EncTemporalFilter::m_chromaFactor = 0.55;
const double EncTemporalFilter::m_sigmaMultiplier = 9.0;
const double EncTemporalFilter::m_sigmaZeroPoint = 10.0;
const int EncTemporalFilter::m_motionVectorFactor = 16;
const int EncTemporalFilter::m_padding = 128;
const int EncTemporalFilter::m_interpolationFilter[16][8] =
{
  {   0,   0,   0,  64,   0,   0,   0,   0 },   //0
  {   0,   1,  -3,  64,   4,  -2,   0,   0 },   //1 -->-->
  {   0,   1,  -6,  62,   9,  -3,   1,   0 },   //2 -->
  {   0,   2,  -8,  60,  14,  -5,   1,   0 },   //3 -->-->
  {   0,   2,  -9,  57,  19,  -7,   2,   0 },   //4
  {   0,   3, -10,  53,  24,  -8,   2,   0 },   //5 -->-->
  {   0,   3, -11,  50,  29,  -9,   2,   0 },   //6 -->
  {   0,   3, -11,  44,  35, -10,   3,   0 },   //7 -->-->
  {   0,   1,  -7,  38,  38,  -7,   1,   0 },   //8
  {   0,   3, -10,  35,  44, -11,   3,   0 },   //9 -->-->
  {   0,   2,  -9,  29,  50, -11,   3,   0 },   //10-->
  {   0,   2,  -8,  24,  53, -10,   3,   0 },   //11-->-->
  {   0,   2,  -7,  19,  57,  -9,   2,   0 },   //12
  {   0,   1,  -5,  14,  60,  -8,   2,   0 },   //13-->-->
  {   0,   1,  -3,   9,  62,  -6,   1,   0 },   //14-->
  {   0,   0,  -2,   4,  64,  -3,   1,   0 }    //15-->-->
};

const double EncTemporalFilter::m_refStrengths[3][2] =
{ // abs(POC offset)
  //  1,    2
  {0.85, 0.60},  // m_range * 2
  {1.20, 1.00},  // m_range
  {0.30, 0.30}   // otherwise
};

EncTemporalFilter::EncTemporalFilter() :
  m_FrameSkip(0),
  m_chromaFormatIDC(NUM_CHROMA_FORMAT),
  m_sourceWidth(0),
  m_sourceHeight(0),
  m_QP(0),
  m_clipInputVideoToRec709Range(false),
  m_inputColourSpaceConvert(NUMBER_INPUT_COLOUR_SPACE_CONVERSIONS)
{}

void EncTemporalFilter::init(const int frameSkip,
  const int inputBitDepth[MAX_NUM_CHANNEL_TYPE],
  const int msbExtendedBitDepth[MAX_NUM_CHANNEL_TYPE],
  const int internalBitDepth[MAX_NUM_CHANNEL_TYPE],
  const int width,
  const int height,
  const int *pad,
  const bool rec709,
  const std::string &filename,
  const ChromaFormat inputChromaFormatIDC,
  const InputColourSpaceConversion colorSpaceConv,
  const int qp,
  const std::map<int, double> &temporalFilterStrengths,
  const bool gopBasedTemporalFilterFutureReference)
{
  m_FrameSkip = frameSkip;
  for (int i = 0; i < MAX_NUM_CHANNEL_TYPE; i++)
  {
    m_inputBitDepth[i] = inputBitDepth[i];
    m_MSBExtendedBitDepth[i] = msbExtendedBitDepth[i];
    m_internalBitDepth[i] = internalBitDepth[i];
  }

  m_sourceWidth = width;
  m_sourceHeight = height;
  for (int i = 0; i < 2; i++)
  {
    m_pad[i] = pad[i];
  }
  m_clipInputVideoToRec709Range = rec709;
  m_inputFileName = filename;
  m_chromaFormatIDC = inputChromaFormatIDC;
  m_inputColourSpaceConvert = colorSpaceConv;
  m_area = Area(0, 0, width, height);
  m_QP = qp;
  m_temporalFilterStrengths = temporalFilterStrengths;
  m_gopBasedTemporalFilterFutureReference = gopBasedTemporalFilterFutureReference;
}

// ====================================================================================================================
// Public member functions
// ====================================================================================================================

bool EncTemporalFilter::filter(PelStorage *orgPic, int receivedPoc)
{
  bool isFilterThisFrame = false;
  if (m_QP >= 17)  // disable filter for QP < 17
  {
    for (map<int, double>::iterator it = m_temporalFilterStrengths.begin(); it != m_temporalFilterStrengths.end(); ++it)
    {
      int filteredFrame = it->first;
      if (receivedPoc % filteredFrame == 0)
      {
        isFilterThisFrame = true;
        break;
      }
    }
  }

  if (isFilterThisFrame)
  {
    int offset = m_FrameSkip;
    VideoIOYuv yuvFrames;
    yuvFrames.open(m_inputFileName, false, m_inputBitDepth, m_MSBExtendedBitDepth, m_internalBitDepth);
    yuvFrames.skipFrames(std::max(offset + receivedPoc - m_range, 0), m_sourceWidth - m_pad[0], m_sourceHeight - m_pad[1], m_chromaFormatIDC);


    std::deque<TemporalFilterSourcePicInfo> srcFrameInfo;

    int firstFrame = receivedPoc + offset - m_range;
    int lastFrame = receivedPoc + offset + m_range;
    if (!m_gopBasedTemporalFilterFutureReference)
    {
      lastFrame = receivedPoc + offset - 1;
    }
    int origOffset = -m_range;

    // subsample original picture so it only needs to be done once
    PelStorage origPadded;

    origPadded.create(m_chromaFormatIDC, m_area, 0, m_padding);
    origPadded.copyFrom(*orgPic);
    origPadded.extendBorderPel(m_padding, m_padding);

    PelStorage origSubsampled2;
    PelStorage origSubsampled4;

    subsampleLuma(origPadded, origSubsampled2);
    subsampleLuma(origSubsampled2, origSubsampled4);

    // determine motion vectors
    for (int poc = firstFrame; poc <= lastFrame; poc++)
    {
      if (poc < 0)
      {
        origOffset++;
        continue; // frame not available
      }
      else if (poc == offset + receivedPoc)
      { // hop over frame that will be filtered
        yuvFrames.skipFrames(1, m_sourceWidth - m_pad[0], m_sourceHeight - m_pad[1], m_chromaFormatIDC);
        origOffset++;
        continue;
      }
      srcFrameInfo.push_back(TemporalFilterSourcePicInfo());
      TemporalFilterSourcePicInfo &srcPic=srcFrameInfo.back();

      PelStorage dummyPicBufferTO; // Only used temporary in yuvFrames.read
      srcPic.picBuffer.create(m_chromaFormatIDC, m_area, 0, m_padding);
      dummyPicBufferTO.create(m_chromaFormatIDC, m_area, 0, m_padding);
      if (!yuvFrames.read(srcPic.picBuffer, dummyPicBufferTO, m_inputColourSpaceConvert, m_pad, m_chromaFormatIDC, m_clipInputVideoToRec709Range))
      {
        return false; // eof or read fail
      }
      srcPic.picBuffer.extendBorderPel(m_padding, m_padding);
      srcPic.mvs.allocate(m_sourceWidth / 4, m_sourceHeight / 4);

      motionEstimation(srcPic.mvs, origPadded, srcPic.picBuffer, origSubsampled2, origSubsampled4);
      srcPic.origOffset = origOffset;
      origOffset++;
    }

    // filter
    PelStorage newOrgPic;
    newOrgPic.create(m_chromaFormatIDC, m_area, 0, m_padding);
    double overallStrength = -1.0;
    for (map<int, double>::iterator it = m_temporalFilterStrengths.begin(); it != m_temporalFilterStrengths.end(); ++it)
    {
      int frame = it->first;
      double strength = it->second;
      if (receivedPoc % frame == 0)
      {
        overallStrength = strength;
      }
    }

    bilateralFilter(origPadded, srcFrameInfo, newOrgPic, overallStrength);

    // move filtered to orgPic
    orgPic->copyFrom(newOrgPic);

    yuvFrames.close();
    return true;
  }
  return false;
}

// ====================================================================================================================
// Private member functions
// ====================================================================================================================

void EncTemporalFilter::subsampleLuma(const PelStorage &input, PelStorage &output, const int factor) const
{
  const int newWidth = input.Y().width / factor;
  const int newHeight = input.Y().height / factor;
  output.create(m_chromaFormatIDC, Area(0, 0, newWidth, newHeight), 0, m_padding);

  const Pel* srcRow = input.Y().buf;
  const int srcStride = input.Y().stride;
  Pel *dstRow = output.Y().buf;
  const int dstStride = output.Y().stride;

  for (int y = 0; y < newHeight; y++, srcRow+=factor*srcStride, dstRow+=dstStride)
  {
    const Pel *inRow      = srcRow;
    const Pel *inRowBelow = srcRow+srcStride;
    Pel *target     = dstRow;

    for (int x = 0; x < newWidth; x++)
    {
      target[x] = (inRow[0] + inRowBelow[0] + inRow[1] + inRowBelow[1] + 2) >> 2;
      inRow += 2;
      inRowBelow += 2;
    }
  }
  output.extendBorderPel(m_padding, m_padding);
}

int EncTemporalFilter::motionErrorLuma(const PelStorage &orig,
  const PelStorage &buffer,
  const int x,
  const int y,
  int dx,
  int dy,
  const int bs,
  const int besterror = 8 * 8 * 1024 * 1024) const
{
  const Pel* origOrigin = orig.Y().buf;
  const int origStride  = orig.Y().stride;
  const Pel *buffOrigin = buffer.Y().buf;
  const int buffStride  = buffer.Y().stride;

  int error = 0;// dx * 10 + dy * 10;
  if (((dx | dy) & 0xF) == 0)
  {
    dx /= m_motionVectorFactor;
    dy /= m_motionVectorFactor;
    for (int y1 = 0; y1 < bs; y1++)
    {
      const Pel* origRowStart = origOrigin + (y+y1)*origStride + x;
      const Pel* bufferRowStart = buffOrigin + (y+y1+dy)*buffStride + (x+dx);
      for (int x1 = 0; x1 < bs; x1 += 2)
      {
        int diff = origRowStart[x1] - bufferRowStart[x1];
        error += diff * diff;
        diff = origRowStart[x1 + 1] - bufferRowStart[x1 + 1];
        error += diff * diff;
      }
      if (error > besterror)
      {
        return error;
      }
    }
  }
  else
  {
    const int *xFilter = m_interpolationFilter[dx & 0xF];
    const int *yFilter = m_interpolationFilter[dy & 0xF];
    int tempArray[64 + 8][64];

    int sum, base;
    for (int y1 = 1; y1 < bs + 7; y1++)
    {
      const int yOffset = y + y1 + (dy >> 4) - 3;
      const Pel *sourceRow = buffOrigin + (yOffset)*buffStride + 0;
      for (int x1 = 0; x1 < bs; x1++)
      {
        sum = 0;
        base = x + x1 + (dx >> 4) - 3;
        const Pel *rowStart = sourceRow + base;

        sum += xFilter[1] * rowStart[1];
        sum += xFilter[2] * rowStart[2];
        sum += xFilter[3] * rowStart[3];
        sum += xFilter[4] * rowStart[4];
        sum += xFilter[5] * rowStart[5];
        sum += xFilter[6] * rowStart[6];

        tempArray[y1][x1] = sum;
      }
    }

    const Pel maxSampleValue = (1<<m_internalBitDepth[CHANNEL_TYPE_LUMA])-1;
    for (int y1 = 0; y1 < bs; y1++)
    {
      const Pel *origRow = origOrigin + (y+y1)*origStride + 0;
      for (int x1 = 0; x1 < bs; x1++)
      {
        sum = 0;
        sum += yFilter[1] * tempArray[y1 + 1][x1];
        sum += yFilter[2] * tempArray[y1 + 2][x1];
        sum += yFilter[3] * tempArray[y1 + 3][x1];
        sum += yFilter[4] * tempArray[y1 + 4][x1];
        sum += yFilter[5] * tempArray[y1 + 5][x1];
        sum += yFilter[6] * tempArray[y1 + 6][x1];

        sum = (sum + (1 << 11)) >> 12;
        sum = sum < 0 ? 0 : (sum > maxSampleValue ? maxSampleValue : sum);

        error += (sum - origRow[x + x1]) * (sum - origRow[x + x1]);
      }
      if (error > besterror)
      {
        return error;
      }
    }
  }
  return error;
}

void EncTemporalFilter::motionEstimationLuma(Array2D<MotionVector> &mvs, const PelStorage &orig, const PelStorage &buffer, const int blockSize,
  const Array2D<MotionVector> *previous, const int factor, const bool doubleRes) const
{
  int range = 5;
  const int stepSize = blockSize;

  const int origWidth  = orig.Y().width;
  const int origHeight = orig.Y().height;

  for (int blockY = 0; blockY + blockSize < origHeight; blockY += stepSize)
  {
    for (int blockX = 0; blockX + blockSize < origWidth; blockX += stepSize)
    {
      MotionVector best;

      if (previous == NULL)
      {
        range = 8;
      }
      else
      {
        for (int py = -2; py <= 2; py++)
        {
          int testy = blockY / (2 * blockSize) + py;
          for (int px = -2; px <= 2; px++)
          {
            int testx = blockX / (2 * blockSize) + px;
            if ((testx >= 0) && (testx < origWidth / (2 * blockSize)) && (testy >= 0) && (testy < origHeight / (2 * blockSize)))
            {
              MotionVector old = previous->get(testx, testy);
              int error = motionErrorLuma(orig, buffer, blockX, blockY, old.x * factor, old.y * factor, blockSize, best.error);
              if (error < best.error)
              {
                best.set(old.x * factor, old.y * factor, error);
              }
            }
          }
        }
      }
      MotionVector prevBest = best;
      for (int y2 = prevBest.y / m_motionVectorFactor - range; y2 <= prevBest.y / m_motionVectorFactor + range; y2++)
      {
        for (int x2 = prevBest.x / m_motionVectorFactor - range; x2 <= prevBest.x / m_motionVectorFactor + range; x2++)
        {
          int error = motionErrorLuma(orig, buffer, blockX, blockY, x2 * m_motionVectorFactor, y2 * m_motionVectorFactor, blockSize, best.error);
          if (error < best.error)
          {
            best.set(x2 * m_motionVectorFactor, y2 * m_motionVectorFactor, error);
          }
        }
      }
      if (doubleRes)
      { // merge into one loop, probably with precision array (here [12, 3] or maybe [4, 1]) with setable number of iterations
        prevBest = best;
        int doubleRange = 3 * 4;
        for (int y2 = prevBest.y - doubleRange; y2 <= prevBest.y + doubleRange; y2 += 4)
        {
          for (int x2 = prevBest.x - doubleRange; x2 <= prevBest.x + doubleRange; x2 += 4)
          {
            int error = motionErrorLuma(orig, buffer, blockX, blockY, x2, y2, blockSize, best.error);
            if (error < best.error)
            {
              best.set(x2, y2, error);
            }

          }
        }

        prevBest = best;
        doubleRange = 3;
        for (int y2 = prevBest.y - doubleRange; y2 <= prevBest.y + doubleRange; y2++)
        {
          for (int x2 = prevBest.x - doubleRange; x2 <= prevBest.x + doubleRange; x2++)
          {
            int error = motionErrorLuma(orig, buffer, blockX, blockY, x2, y2, blockSize, best.error);
            if (error < best.error)
            {
              best.set(x2, y2, error);
            }

          }
        }

      }
      mvs.get(blockX / stepSize, blockY / stepSize) = best;
    }
  }
}

void EncTemporalFilter::motionEstimation(Array2D<MotionVector> &mv, const PelStorage &orgPic, const PelStorage &buffer, const PelStorage &origSubsampled2, const PelStorage &origSubsampled4) const
{
  const int width = m_sourceWidth;
  const int height = m_sourceHeight;
  Array2D<MotionVector> mv_0(width / 16, height / 16);
  Array2D<MotionVector> mv_1(width / 16, height / 16);
  Array2D<MotionVector> mv_2(width / 16, height / 16);

  PelStorage bufferSub2;
  PelStorage bufferSub4;

  subsampleLuma(buffer, bufferSub2);
  subsampleLuma(bufferSub2, bufferSub4);

  motionEstimationLuma(mv_0, origSubsampled4, bufferSub4, 16);
  motionEstimationLuma(mv_1, origSubsampled2, bufferSub2, 16, &mv_0, 2);
  motionEstimationLuma(mv_2, orgPic, buffer, 16, &mv_1, 2);

  motionEstimationLuma(mv, orgPic, buffer, 8, &mv_2, 1, true);
}

void EncTemporalFilter::applyMotion(const Array2D<MotionVector> &mvs, const PelStorage &input, PelStorage &output) const
{
  static const int lumaBlockSize=8;

  for(int c=0; c< getNumberValidComponents(m_chromaFormatIDC); c++)
  {
    const ComponentID compID=(ComponentID)c;
    const int csx=getComponentScaleX(compID, m_chromaFormatIDC);
    const int csy=getComponentScaleY(compID, m_chromaFormatIDC);
    const int blockSizeX = lumaBlockSize>>csx;
    const int blockSizeY = lumaBlockSize>>csy;
    const int height = input.bufs[c].height;
    const int width  = input.bufs[c].width;

    const Pel maxValue = (1<<m_internalBitDepth[toChannelType(compID)])-1;

    const Pel *srcImage = input.bufs[c].buf;
    const int srcStride  = input.bufs[c].stride;

    Pel *dstImage = output.bufs[c].buf;
    int dstStride  = output.bufs[c].stride;

    for (int y = 0, blockNumY = 0; y + blockSizeY <= height; y += blockSizeY, blockNumY++)
    {
      for (int x = 0, blockNumX = 0; x + blockSizeX <= width; x += blockSizeX, blockNumX++)
      {
        const MotionVector &mv = mvs.get(blockNumX,blockNumY);
        const int dx = mv.x >> csx ;
        const int dy = mv.y >> csy ;
        const int xInt = mv.x >> (4+csx) ;
        const int yInt = mv.y >> (4+csy) ;

        const int *xFilter = m_interpolationFilter[dx & 0xf];
        const int *yFilter = m_interpolationFilter[dy & 0xf]; // will add 6 bit.
        const int numFilterTaps=7;
        const int centreTapOffset=3;

        int tempArray[lumaBlockSize + numFilterTaps][lumaBlockSize];

        for (int by = 1; by < blockSizeY + numFilterTaps; by++)
        {
          const int yOffset = y + by + yInt - centreTapOffset;
          const Pel *sourceRow = srcImage+yOffset*srcStride;
          for (int bx = 0; bx < blockSizeX; bx++)
          {
            int base = x + bx + xInt - centreTapOffset;
            const Pel *rowStart = sourceRow + base;

            int sum = 0;
            sum += xFilter[1] * rowStart[1];
            sum += xFilter[2] * rowStart[2];
            sum += xFilter[3] * rowStart[3];
            sum += xFilter[4] * rowStart[4];
            sum += xFilter[5] * rowStart[5];
            sum += xFilter[6] * rowStart[6];

            tempArray[by][bx] = sum;
          }
        }

        Pel *dstRow = dstImage+y*dstStride;
        for (int by = 0; by < blockSizeY; by++, dstRow+=dstStride)
        {
          Pel *dstPel=dstRow+x;
          for (int bx = 0; bx < blockSizeX; bx++, dstPel++)
          {
            int sum = 0;

            sum += yFilter[1] * tempArray[by + 1][bx];
            sum += yFilter[2] * tempArray[by + 2][bx];
            sum += yFilter[3] * tempArray[by + 3][bx];
            sum += yFilter[4] * tempArray[by + 4][bx];
            sum += yFilter[5] * tempArray[by + 5][bx];
            sum += yFilter[6] * tempArray[by + 6][bx];

            sum = (sum + (1 << 11)) >> 12;
            sum = sum < 0 ? 0 : (sum > maxValue ? maxValue : sum);
            *dstPel = sum;
          }
        }
      }
    }
  }
}

void EncTemporalFilter::bilateralFilter(const PelStorage &orgPic,
  const std::deque<TemporalFilterSourcePicInfo> &srcFrameInfo,
  PelStorage &newOrgPic,
  double overallStrength) const
{
  const int numRefs = int(srcFrameInfo.size());
  std::vector<PelStorage> correctedPics(numRefs);
  for (int i = 0; i < numRefs; i++)
  {
    correctedPics[i].create(m_chromaFormatIDC, m_area, 0, m_padding);
    applyMotion(srcFrameInfo[i].mvs, srcFrameInfo[i].picBuffer, correctedPics[i]);
  }

  int refStrengthRow = 2;
  if (numRefs == m_range*2)
  {
    refStrengthRow = 0;
  }
  else if (numRefs == m_range)
  {
    refStrengthRow = 1;
  }

  const double lumaSigmaSq = (m_QP - m_sigmaZeroPoint) * (m_QP - m_sigmaZeroPoint) * m_sigmaMultiplier;
  const double chromaSigmaSq = 30 * 30;

  for(int c=0; c< getNumberValidComponents(m_chromaFormatIDC); c++)
  {
    const ComponentID compID=(ComponentID)c;
    const int height = orgPic.bufs[c].height;
    const int width  = orgPic.bufs[c].width;
    const Pel *srcPelRow = orgPic.bufs[c].buf;
    const int srcStride = orgPic.bufs[c].stride;
    Pel *dstPelRow = newOrgPic.bufs[c].buf;
    const int dstStride = newOrgPic.bufs[c].stride;
    const double sigmaSq = isChroma(compID)? chromaSigmaSq : lumaSigmaSq;
    const double weightScaling = overallStrength * (isChroma(compID) ? m_chromaFactor : 0.4);
    const Pel maxSampleValue = (1<<m_internalBitDepth[toChannelType(compID)])-1;
    const double bitDepthDiffWeighting=1024.0 / (maxSampleValue+1);

    for (int y = 0; y < height; y++, srcPelRow+=srcStride, dstPelRow+=dstStride)
    {
      const Pel *srcPel=srcPelRow;
      Pel *dstPel=dstPelRow;
      for (int x = 0; x < width; x++, srcPel++, dstPel++)
      {
        const int orgVal = (int) *srcPel;
        double temporalWeightSum = 1.0;
        double newVal = (double) orgVal;
        for (int i = 0; i < numRefs; i++)
        {
          const Pel *pCorrectedPelPtr=correctedPics[i].bufs[c].buf+(y*correctedPics[i].bufs[c].stride+x);
          const int refVal = (int) *pCorrectedPelPtr;
          double diff = (double)(refVal - orgVal);
          diff *= bitDepthDiffWeighting;
          double diffSq = diff * diff;
          const int index = std::min(1, std::abs(srcFrameInfo[i].origOffset) - 1);
          const double weight = weightScaling * m_refStrengths[refStrengthRow][index] * exp(-diffSq / (2 * sigmaSq));
          newVal += weight * refVal;
          temporalWeightSum += weight;
        }
        newVal /= temporalWeightSum;
        Pel sampleVal = (Pel)round(newVal);
        sampleVal=(sampleVal<0?0 : (sampleVal>maxSampleValue ? maxSampleValue : sampleVal));
        *dstPel = sampleVal;
      }
    }
  }
}

//! \}