/work/vvenc/source/Lib/EncoderLib/EncSampleAdaptiveOffset.cpp

Source
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/**
 \file     EncSampleAdaptiveOffset.cpp
 \brief       estimation part of sample adaptive offset class
 */

#include "EncSampleAdaptiveOffset.h"
#include "CommonLib/UnitTools.h"
#include "CommonLib/dtrace_codingstruct.h"
#include "CommonLib/dtrace_buffer.h"
#include "CommonLib/CodingStructure.h"
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include "vvenc/vvencCfg.h"

//! \ingroup EncoderLib
//! \{

namespace vvenc {


#define SAOCtx(c) SubCtx( Ctx::Sao, c )


//! rounding with IBDI
inline double xRoundIbdi2(int bitDepth, double x)
{
  return ((x) >= 0 ? ((int)((x) + 0.5)) : ((int)((x) -0.5)));
}

inline double xRoundIbdi(int bitDepth, double x)
{
  return (bitDepth > 8 ? xRoundIbdi2(bitDepth, (x)) : ((x)>=0 ? ((int)((x)+0.5)) : ((int)((x)-0.5)))) ;
}


void SaoPreFilterEdges::create( const ChromaFormat chFmt, const PreCalcValues& pcv )
{
  for( int compIdx = 0; compIdx < getNumberValidComponents( chFmt ); compIdx++ )
  {
    const ComponentID compID = ComponentID( compIdx );
    width    [compIdx] = pcv.lumaWidth >> getComponentScaleX( compID, chFmt );
    ctuHeight[compIdx] = pcv.maxCUSize >> getComponentScaleY( compID, chFmt );
    bottomRows[compIdx].resize( pcv.heightInCtus * width[compIdx] );
    rightCols [compIdx].resize( pcv.heightInCtus * ctuHeight[compIdx] );
  }
}

EncSampleAdaptiveOffset::EncSampleAdaptiveOffset()
  : m_CABACEstimator( nullptr )
  , m_CtxCache      ( nullptr )
  , m_ctuPreSao     ( nullptr )
{
}

EncSampleAdaptiveOffset::~EncSampleAdaptiveOffset()
{
}

void EncSampleAdaptiveOffset::init( const VVEncCfg& encCfg )
{
  m_EncCfg = &encCfg;

  if ( encCfg.m_bUseSAO )
  {
    SampleAdaptiveOffset::init( encCfg.m_internChromaFormat, encCfg.m_CTUSize, encCfg.m_CTUSize, encCfg.m_log2SaoOffsetScale[CH_L], encCfg.m_log2SaoOffsetScale[CH_C] );
  }
}

void EncSampleAdaptiveOffset::initSlice( const Slice* slice )
{
  memcpy( m_lambda, slice->getLambdas(), sizeof( m_lambda ) );
}

void EncSampleAdaptiveOffset::setCtuEncRsrc( CABACWriter* cabacEstimator, CtxCache* ctxCache, PelStorage* ctuPreSaoBuf )
{
  m_CABACEstimator = cabacEstimator;
  m_CtxCache       = ctxCache;
  m_ctuPreSao      = ctuPreSaoBuf;
}

void EncSampleAdaptiveOffset::disabledRate( CodingStructure& cs, double saoDisabledRate[ MAX_NUM_COMP ][ VVENC_MAX_TLAYER ], SAOBlkParam* reconParams, const double saoEncodingRate, const double saoEncodingRateChroma, const ChromaFormat& chromaFormat )
{
  if ( saoEncodingRate > 0.0 )
  {
    const PreCalcValues& pcv     = *cs.pcv;
    const int numberOfComponents = getNumberValidComponents( chromaFormat );
    const int picTempLayer       = cs.slice->TLayer;
    int numCtusForSAOOff[MAX_NUM_COMP];

    for (int compIdx = 0; compIdx < numberOfComponents; compIdx++)
    {
      numCtusForSAOOff[compIdx] = 0;
      for( int ctuRsAddr=0; ctuRsAddr< pcv.sizeInCtus; ctuRsAddr++)
      {
        if( reconParams[ctuRsAddr][compIdx].modeIdc == SAO_MODE_OFF)
        {
          numCtusForSAOOff[compIdx]++;
        }
      }
    }
    if (saoEncodingRateChroma > 0.0)
    {
      for (int compIdx = 0; compIdx < numberOfComponents; compIdx++)
      {
        saoDisabledRate[compIdx][picTempLayer] = (double)numCtusForSAOOff[compIdx]/(double)pcv.sizeInCtus;
      }
    }
    else if (picTempLayer == 0)
    {
      saoDisabledRate[COMP_Y][0] = (double)(numCtusForSAOOff[COMP_Y]+numCtusForSAOOff[COMP_Cb]+numCtusForSAOOff[COMP_Cr])/(double)(pcv.sizeInCtus *3);
    }
  }
}

void EncSampleAdaptiveOffset::decidePicParams( const CodingStructure& cs, double saoDisabledRate[ MAX_NUM_COMP ][ VVENC_MAX_TLAYER ], bool saoEnabled[ MAX_NUM_COMP ], const double saoEncodingRate, const double saoEncodingRateChroma, const ChromaFormat& chromaFormat )
{
  const Slice& slice           = *cs.slice;
  const int numberOfComponents = getNumberValidComponents( chromaFormat );

  // reset
  if( slice.pendingRasInit )
  {
    for( int compIdx = 0; compIdx < MAX_NUM_COMP; compIdx++ )
    {
      for( int tempLayer = 1; tempLayer < VVENC_MAX_TLAYER; tempLayer++ )
      {
        saoDisabledRate[ compIdx ][ tempLayer ] = 0.0;
      }
    }
  }

  for( int compIdx = 0; compIdx < MAX_NUM_COMP; compIdx++ )
  {
    saoEnabled[ compIdx ] = false;
  }

  const int picTempLayer = slice.TLayer;
  for( int compIdx = 0; compIdx < numberOfComponents; compIdx++ )
  {
    // enable per default
    saoEnabled[ compIdx ] = true;

    if( saoEncodingRate > 0.0 )
    {
      if( saoEncodingRateChroma > 0.0 )
      {
        // decide slice-level on/off based on previous results
        if( ( picTempLayer > 0 )
          && ( saoDisabledRate[ compIdx ][ picTempLayer - 1 ] > ( ( compIdx == COMP_Y ) ? saoEncodingRate : saoEncodingRateChroma ) ) )
        {
          saoEnabled[ compIdx ] = false;
        }
      }
      else
      {
        // decide slice-level on/off based on previous results
        if( ( picTempLayer > 0 )
          && ( saoDisabledRate[ COMP_Y ][ 0 ] > saoEncodingRate ) )
        {
          saoEnabled[ compIdx ] = false;
        }
      }
    }
  }
}

void EncSampleAdaptiveOffset::loadCtuPreSao( CodingStructure& cs, const UnitArea& ctuArea, const int ctuY, SaoPreFilterEdges& edges )
{
  // SAO of a CTU reads the CTU and one sample around it, all as they were before SAO. CTUs are
  // filtered row by row from the left, so the reconstruction still holds these samples for the CTU
  // itself and for the neighbours right of and below it. The CTUs above and to the left are
  // filtered already, and their edges come from the copies they saved here.
  const PelUnitBuf reco = cs.picture->getRecoBuf();

  for( int compIdx = 0; compIdx < getNumberValidComponents( ctuArea.chromaFormat ); compIdx++ )
  {
    const ComponentID compID = ComponentID( compIdx );
    const CompArea&   area   = ctuArea.block( compID );
    const CPelBuf     src    = reco.get( compID );
    PelBuf            ctu    = m_ctuPreSao->get( compID );

    const int x        = area.x;
    const int y        = area.y;
    const int w        = area.width;
    const int h        = area.height;
    const int colBegin = x > 0 ? -1 : 0;
    const int colEnd   = x + w < ( int ) src.width ? w + 1 : w;
    Pel* const savedRow = &edges.bottomRows[compIdx][ctuY * edges.width[compIdx]];
    Pel* const savedCol = &edges.rightCols [compIdx][ctuY * edges.ctuHeight[compIdx]];

    // the row above, saved by the CTU row above
    if( y > 0 )
    {
      const Pel* rowAbove = &edges.bottomRows[compIdx][( ctuY - 1 ) * edges.width[compIdx]];
      std::copy( rowAbove + x + colBegin, rowAbove + x + colEnd, ctu.bufAt( colBegin, -1 ) );
    }
    // the CTU and the column right of it
    for( int r = 0; r < h; r++ )
    {
      const Pel* line = src.bufAt( x, y + r );
      std::copy( line, line + colEnd, ctu.bufAt( 0, r ) );
    }
    // the column left of it, saved by the CTU to the left
    if( x > 0 )
    {
      for( int r = 0; r < h; r++ )
      {
        ctu.at( -1, r ) = savedCol[r];
      }
    }
    // the row below
    if( y + h < ( int ) src.height )
    {
      const Pel* line = src.bufAt( x, y + h );
      std::copy( line + colBegin, line + colEnd, ctu.bufAt( colBegin, h ) );
    }

    // save this CTU's bottom row and right column for the CTUs filtered after it
    std::copy( ctu.bufAt( 0, h - 1 ), ctu.bufAt( 0, h - 1 ) + w, savedRow + x );
    for( int r = 0; r < h; r++ )
    {
      savedCol[r] = ctu.at( w - 1, r );
    }
  }
}

void EncSampleAdaptiveOffset::getCtuStatistics( CodingStructure& cs, std::vector<SAOStatData**>& saoStatistics, const UnitArea& ctuArea, const int ctuRsAddr )
{
  const PreCalcValues& pcv     = *cs.pcv;
  const int numberOfComponents = getNumberValidComponents( pcv.chrFormat );
  bool isLeftAvail             = false;
  bool isRightAvail            = false;
  bool isAboveAvail            = false;
  bool isBelowAvail            = false;
  bool isAboveLeftAvail        = false;
  bool isAboveRightAvail       = false;

  deriveLoopFilterBoundaryAvailibility( cs, ctuArea.Y(), isLeftAvail, isAboveAvail, isAboveLeftAvail );

  // NOTE: The number of skipped lines during gathering CTU statistics depends on the slice boundary availabilities.
  // For simplicity, here only picture boundaries are considered.

  isRightAvail      = ( ctuArea.Y().x + pcv.maxCUSize < pcv.lumaWidth  );
  isBelowAvail      = ( ctuArea.Y().y + pcv.maxCUSize < pcv.lumaHeight );
  isAboveRightAvail = ( ( ctuArea.Y().y > 0 ) && ( isRightAvail ) );

  CHECK( !cs.pps->loopFilterAcrossSlicesEnabled, "Not implemented" );
  if( cs.pps->getNumTiles() > 1 && !cs.pps->loopFilterAcrossTilesEnabled )
  {
    const int ctuX    = ctuArea.lx() >> cs.pcv->maxCUSizeLog2;
    const int ctuY    = ctuArea.ly() >> cs.pcv->maxCUSizeLog2;
    isRightAvail      = isRightAvail      && cs.pps->canFilterCtuBdry( ctuX, ctuY,  1, 0 );
    isBelowAvail      = isBelowAvail      && cs.pps->canFilterCtuBdry( ctuX, ctuY,  0, 1 );
    isAboveRightAvail = isAboveRightAvail && cs.pps->canFilterCtuBdry( ctuX, ctuY,  1,-1 );
  }

  //VirtualBoundaries vb;
  //bool isCtuCrossedByVirtualBoundaries = vb.isCrossedByVirtualBoundaries(xPos, yPos, width, height, cs.slice->pps);

  for( int compIdx = 0; compIdx < numberOfComponents; compIdx++ )
  {
    const ComponentID compID = ComponentID( compIdx );
    const CompArea& compArea = ctuArea.block( compID );

    PelBuf srcBuf = m_ctuPreSao->get( compID );
    PelBuf orgBuf = cs.picture->getOrigBuf().get( compID );

    getBlkStats( compID,
                 cs.sps->bitDepths[ toChannelType( compID ) ],
                 saoStatistics[ ctuRsAddr ][ compID ],
                 srcBuf.buf,
                 orgBuf.bufAt( compArea ),
                 srcBuf.stride,
                 orgBuf.stride,
                 compArea.width,
                 compArea.height,
                 isLeftAvail, isRightAvail, isAboveAvail, isBelowAvail, isAboveLeftAvail, isAboveRightAvail
               );
  }
}

void EncSampleAdaptiveOffset::getStatistics(std::vector<SAOStatData**>& blkStats, PelUnitBuf& orgYuv, PelUnitBuf& srcYuv, CodingStructure& cs )
{
  bool isLeftAvail, isRightAvail, isAboveAvail, isBelowAvail, isAboveLeftAvail, isAboveRightAvail;

  const PreCalcValues& pcv = *cs.pcv;
  const int numberOfComponents = getNumberValidComponents(pcv.chrFormat);

  size_t lineBufferSize = pcv.maxCUSize + 1;
  if (m_signLineBuf1.size() != lineBufferSize)
  {
    m_signLineBuf1.resize(lineBufferSize);
    m_signLineBuf2.resize(lineBufferSize);
  }

  int ctuRsAddr = 0;
  for( uint32_t yPos = 0; yPos < pcv.lumaHeight; yPos += pcv.maxCUSize )
  {
    for( uint32_t xPos = 0; xPos < pcv.lumaWidth; xPos += pcv.maxCUSize )
    {
      const uint32_t width  = (xPos + pcv.maxCUSize  > pcv.lumaWidth)  ? (pcv.lumaWidth - xPos)  : pcv.maxCUSize;
      const uint32_t height = (yPos + pcv.maxCUSize > pcv.lumaHeight) ? (pcv.lumaHeight - yPos) : pcv.maxCUSize;
      const UnitArea area( cs.area.chromaFormat, Area(xPos , yPos, width, height) );

      deriveLoopFilterBoundaryAvailibility(cs, area.Y(), isLeftAvail, isAboveAvail, isAboveLeftAvail );

      //NOTE: The number of skipped lines during gathering CTU statistics depends on the slice boundary availabilities.
      //For simplicity, here only picture boundaries are considered.

      isRightAvail      = (xPos + pcv.maxCUSize  < pcv.lumaWidth );
      isBelowAvail      = (yPos + pcv.maxCUSize < pcv.lumaHeight);
      isAboveRightAvail = ((yPos > 0) && (isRightAvail));

      for(int compIdx = 0; compIdx < numberOfComponents; compIdx++)
      {
        const ComponentID compID = ComponentID(compIdx);
        const CompArea& compArea = area.block( compID );

        int  srcStride  = srcYuv.get(compID).stride;
        Pel* srcBlk     = srcYuv.get(compID).bufAt( compArea );

        int  orgStride  = orgYuv.get(compID).stride;
        Pel* orgBlk     = orgYuv.get(compID).bufAt( compArea );

        getBlkStats(compID, cs.sps->bitDepths[toChannelType(compID)], blkStats[ctuRsAddr][compID]
                  , srcBlk, orgBlk, srcStride, orgStride, compArea.width, compArea.height
                  , isLeftAvail,  isRightAvail, isAboveAvail, isBelowAvail, isAboveLeftAvail, isAboveRightAvail );
      }
      ctuRsAddr++;
    }
  }
}

void EncSampleAdaptiveOffset::decideCtuParams( CodingStructure& cs, const std::vector<SAOStatData**>& saoStatistics, const bool saoEnabled[ MAX_NUM_COMP ], const bool allBlksDisabled, const UnitArea& ctuArea, const int ctuRsAddr, SAOBlkParam* reconParams, SAOBlkParam* codedParams )
{
  const PreCalcValues& pcv = *cs.pcv;
  const Slice& slice       = *cs.slice;
  const int  ctuPosX       = ctuRsAddr % pcv.widthInCtus;
  const int  ctuPosY       = ctuRsAddr / pcv.widthInCtus;

  // reset CABAC estimator
  if( m_EncCfg->m_ensureWppBitEqual
      && m_EncCfg->m_numThreads < 1
      && ctuPosX == 0
      && ctuPosY > 0 )
  {
    m_CABACEstimator->initCtxModels( slice );
  }

  // check disabled
  if( allBlksDisabled )
  {
    codedParams[ ctuRsAddr ].reset();
    return;
  }

  // get merge list
  SAOBlkParam* mergeList[ NUM_SAO_MERGE_TYPES ] = { NULL };
  getMergeList( cs, ctuRsAddr, reconParams, mergeList );

  const TempCtx ctxStart( m_CtxCache, SAOCtx( m_CABACEstimator->getCtx() ) );
  TempCtx       ctxBest ( m_CtxCache );

  SAOBlkParam modeParam;
  double minCost  = MAX_DOUBLE;
  double modeCost = MAX_DOUBLE;
  for( int mode = 1; mode < NUM_SAO_MODES; mode++ )
  {
    if( mode > 1 )
    {
      m_CABACEstimator->getCtx() = SAOCtx( ctxStart );
    }
    switch( mode )
    {
    case SAO_MODE_NEW:
      {
        deriveModeNewRDO( cs.sps->bitDepths, ctuRsAddr, mergeList, saoEnabled, saoStatistics, modeParam, modeCost );
      }
      break;
    case SAO_MODE_MERGE:
      {
        deriveModeMergeRDO( cs.sps->bitDepths, ctuRsAddr, mergeList, saoEnabled, saoStatistics, modeParam, modeCost );
      }
      break;
    default:
      {
        THROW( "Not a supported SAO mode." );
      }
    }

    if( modeCost < minCost )
    {
      minCost                  = modeCost;
      codedParams[ ctuRsAddr ] = modeParam;
      ctxBest                  = SAOCtx( m_CABACEstimator->getCtx() );
    }
  }

  // apply reconstructed offsets
  m_CABACEstimator->getCtx() = SAOCtx( ctxBest );
  reconParams[ ctuRsAddr ] = codedParams[ ctuRsAddr ];

  reconstructBlkSAOParam( reconParams[ ctuRsAddr ], mergeList );

  offsetCTU( ctuArea, *m_ctuPreSao, cs.getRecoBuf(), reconParams[ ctuRsAddr ], cs );
}

int64_t EncSampleAdaptiveOffset::getDistortion(const int channelBitDepth, int typeIdc, int typeAuxInfo, int* invQuantOffset, SAOStatData& statData)
{
  int64_t dist        = 0;
  int shift = 2 * DISTORTION_PRECISION_ADJUSTMENT(channelBitDepth);

  switch(typeIdc)
  {
  case SAO_TYPE_EO_0:
  case SAO_TYPE_EO_90:
  case SAO_TYPE_EO_135:
  case SAO_TYPE_EO_45:
    {
      for (int offsetIdx=0; offsetIdx<NUM_SAO_EO_CLASSES; offsetIdx++)
      {
        dist += estSaoDist( statData.count[offsetIdx], invQuantOffset[offsetIdx], statData.diff[offsetIdx], shift);
      }
    }
    break;
  case SAO_TYPE_BO:
    {
      for (int offsetIdx=typeAuxInfo; offsetIdx<typeAuxInfo+4; offsetIdx++)
      {
        int bandIdx = offsetIdx % NUM_SAO_BO_CLASSES ;
        dist += estSaoDist( statData.count[bandIdx], invQuantOffset[bandIdx], statData.diff[bandIdx], shift);
      }
    }
    break;
  default:
    {
      THROW("Not a supported type");
    }
  }

  return dist;
}

inline int64_t EncSampleAdaptiveOffset::estSaoDist(int64_t count, int64_t offset, int64_t diffSum, int shift)
{
  return (( count*offset*offset-diffSum*offset*2 ) >> shift);
}


inline int EncSampleAdaptiveOffset::estIterOffset(int typeIdx, double lambda, int offsetInput, int64_t count, int64_t diffSum, int shift, int bitIncrease, int64_t& bestDist, double& bestCost, int offsetTh )
{
  int iterOffset, tempOffset;
  int64_t tempDist, tempRate;
  double tempCost, tempMinCost;
  int offsetOutput = 0;
  iterOffset = offsetInput;
  // Assuming sending quantized value 0 results in zero offset and sending the value zero needs 1 bit. entropy coder can be used to measure the exact rate here.
  tempMinCost = lambda;
  while (iterOffset != 0)
  {
    // Calculate the bits required for signaling the offset
    tempRate = (typeIdx == SAO_TYPE_BO) ? (abs((int)iterOffset)+2) : (abs((int)iterOffset)+1);
    if (abs((int)iterOffset)==offsetTh) //inclusive
    {
      tempRate --;
    }
    // Do the dequantization before distortion calculation
    tempOffset  = iterOffset * (1<< bitIncrease);
    tempDist    = estSaoDist( count, tempOffset, diffSum, shift);
    tempCost    = ((double)tempDist + lambda * (double) tempRate);
    if(tempCost < tempMinCost)
    {
      tempMinCost = tempCost;
      offsetOutput = iterOffset;
      bestDist = tempDist;
      bestCost = tempCost;
    }
    iterOffset = (iterOffset > 0) ? (iterOffset-1):(iterOffset+1);
  }
  return offsetOutput;
}

void EncSampleAdaptiveOffset::deriveOffsets(ComponentID compIdx, const int channelBitDepth, int typeIdc, SAOStatData& statData, int* quantOffsets, int& typeAuxInfo)
{
  int bitDepth = channelBitDepth;
  int shift = 2 * DISTORTION_PRECISION_ADJUSTMENT(bitDepth);
  int offsetTh = SampleAdaptiveOffset::getMaxOffsetQVal(channelBitDepth);  //inclusive

  ::memset(quantOffsets, 0, sizeof(int)*MAX_NUM_SAO_CLASSES);

  //derive initial offsets
  int numClasses = (typeIdc == SAO_TYPE_BO)?((int)NUM_SAO_BO_CLASSES):((int)NUM_SAO_EO_CLASSES);
  for(int classIdx=0; classIdx< numClasses; classIdx++)
  {
    if( (typeIdc != SAO_TYPE_BO) && (classIdx==SAO_CLASS_EO_PLAIN)  )
    {
      continue; //offset will be zero
    }

    if(statData.count[classIdx] == 0)
    {
      continue; //offset will be zero
    }
#if (  DISTORTION_PRECISION_ADJUSTMENT(x)  == 0 )
    quantOffsets[classIdx] =
       (int) xRoundIbdi(bitDepth, (double)(statData.diff[classIdx] ) / (double)(statData.count[classIdx] << m_offsetStepLog2[compIdx]));
     quantOffsets[classIdx] = Clip3(-offsetTh, offsetTh, quantOffsets[classIdx]);
#else
      quantOffsets[classIdx] =
        (int) xRoundIbdi(bitDepth, (double)(statData.diff[classIdx] << DISTORTION_PRECISION_ADJUSTMENT(bitDepth))
                                     / (double)(statData.count[classIdx] << m_offsetStepLog2[compIdx]));
      quantOffsets[classIdx] = Clip3(-offsetTh, offsetTh, quantOffsets[classIdx]);
#endif
  }

  // adjust offsets
  switch(typeIdc)
  {
  case SAO_TYPE_EO_0:
  case SAO_TYPE_EO_90:
  case SAO_TYPE_EO_135:
  case SAO_TYPE_EO_45:
    {
      int64_t classDist;
      double classCost;
      for(int classIdx=0; classIdx<NUM_SAO_EO_CLASSES; classIdx++)
      {
        if(classIdx==SAO_CLASS_EO_FULL_VALLEY && quantOffsets[classIdx] < 0)
        {
          quantOffsets[classIdx] =0;
        }
        if(classIdx==SAO_CLASS_EO_HALF_VALLEY && quantOffsets[classIdx] < 0)
        {
          quantOffsets[classIdx] =0;
        }
        if(classIdx==SAO_CLASS_EO_HALF_PEAK   && quantOffsets[classIdx] > 0)
        {
          quantOffsets[classIdx] =0;
        }
        if(classIdx==SAO_CLASS_EO_FULL_PEAK   && quantOffsets[classIdx] > 0)
        {
          quantOffsets[classIdx] =0;
        }

        if( quantOffsets[classIdx] != 0 ) //iterative adjustment only when derived offset is not zero
        {
          quantOffsets[classIdx] = estIterOffset( typeIdc, m_lambda[compIdx], quantOffsets[classIdx], statData.count[classIdx], statData.diff[classIdx], shift, m_offsetStepLog2[compIdx], classDist , classCost , offsetTh );
        }
      }

      typeAuxInfo =0;
    }
    break;
  case SAO_TYPE_BO:
    {
      int64_t  distBOClasses[NUM_SAO_BO_CLASSES];
      double costBOClasses[NUM_SAO_BO_CLASSES];
      ::memset(distBOClasses, 0, sizeof(int64_t)*NUM_SAO_BO_CLASSES);
      for(int classIdx=0; classIdx< NUM_SAO_BO_CLASSES; classIdx++)
      {
        costBOClasses[classIdx]= m_lambda[compIdx];
        if( quantOffsets[classIdx] != 0 ) //iterative adjustment only when derived offset is not zero
        {
          quantOffsets[classIdx] = estIterOffset( typeIdc, m_lambda[compIdx], quantOffsets[classIdx], statData.count[classIdx], statData.diff[classIdx], shift, m_offsetStepLog2[compIdx], distBOClasses[classIdx], costBOClasses[classIdx], offsetTh );
        }
      }

      //decide the starting band index
      double minCost = MAX_DOUBLE, cost;
      for(int band=0; band< NUM_SAO_BO_CLASSES; band++)
      {
        cost  = costBOClasses[(band  )%NUM_SAO_BO_CLASSES];
        cost += costBOClasses[(band+1)%NUM_SAO_BO_CLASSES];
        cost += costBOClasses[(band+2)%NUM_SAO_BO_CLASSES];
        cost += costBOClasses[(band+3)%NUM_SAO_BO_CLASSES];

        if(cost < minCost)
        {
          minCost = cost;
          typeAuxInfo = band;
        }
      }
      //clear those unused classes
      int clearQuantOffset[NUM_SAO_BO_CLASSES];
      ::memset(clearQuantOffset, 0, sizeof(int)*NUM_SAO_BO_CLASSES);
      for(int i=0; i< 4; i++)
      {
        int band = (typeAuxInfo+i)%NUM_SAO_BO_CLASSES;
        clearQuantOffset[band] = quantOffsets[band];
      }
      ::memcpy(quantOffsets, clearQuantOffset, sizeof(int)*NUM_SAO_BO_CLASSES);
    }
    break;
  default:
    {
      THROW("Not a supported type");
    }
  }
}

void EncSampleAdaptiveOffset::deriveModeNewRDO(const BitDepths &bitDepths, int ctuRsAddr, SAOBlkParam* mergeList[NUM_SAO_MERGE_TYPES], const bool* sliceEnabled, const std::vector<SAOStatData**>& blkStats, SAOBlkParam& modeParam, double& modeNormCost )
{
  double minCost, cost;
  uint64_t previousFracBits;
  const int numberOfComponents = m_numberOfComponents;

  int64_t dist[MAX_NUM_COMP], modeDist[MAX_NUM_COMP];
  SAOOffset testOffset[MAX_NUM_COMP];
  int invQuantOffset[MAX_NUM_SAO_CLASSES];
  for(int comp=0; comp < MAX_NUM_COMP; comp++)
  {
    modeDist[comp] = 0;
  }

  //pre-encode merge flags
  modeParam[COMP_Y].modeIdc = SAO_MODE_OFF;
  const TempCtx ctxStartBlk   ( m_CtxCache, SAOCtx( m_CABACEstimator->getCtx() ) );
  m_CABACEstimator->sao_block_pars( modeParam, bitDepths, sliceEnabled, (mergeList[SAO_MERGE_LEFT]!= NULL), (mergeList[SAO_MERGE_ABOVE]!= NULL), true );
  const TempCtx ctxStartLuma  ( m_CtxCache, SAOCtx( m_CABACEstimator->getCtx() ) );
  TempCtx       ctxBestLuma   ( m_CtxCache );

    //------ luma --------//
  {
    const ComponentID compIdx = COMP_Y;
    //"off" case as initial cost
    modeParam[compIdx].modeIdc = SAO_MODE_OFF;
    m_CABACEstimator->resetBits();
    m_CABACEstimator->sao_offset_pars( modeParam[compIdx], compIdx, sliceEnabled[compIdx], bitDepths[CH_L] );
    modeDist[compIdx] = 0;
    minCost           = m_lambda[compIdx] * (FRAC_BITS_SCALE * m_CABACEstimator->getEstFracBits());
    ctxBestLuma = SAOCtx( m_CABACEstimator->getCtx() );
    if(sliceEnabled[compIdx])
    {
      for(int typeIdc=0; typeIdc< NUM_SAO_NEW_TYPES; typeIdc++)
      {
        testOffset[compIdx].modeIdc = SAO_MODE_NEW;
        testOffset[compIdx].typeIdc = typeIdc;

        //derive coded offset
        deriveOffsets(compIdx, bitDepths[CH_L], typeIdc, blkStats[ctuRsAddr][compIdx][typeIdc], testOffset[compIdx].offset, testOffset[compIdx].typeAuxInfo);

        //inversed quantized offsets
        invertQuantOffsets(compIdx, typeIdc, testOffset[compIdx].typeAuxInfo, invQuantOffset, testOffset[compIdx].offset);

        //get distortion
        dist[compIdx] = getDistortion(bitDepths[CH_L], testOffset[compIdx].typeIdc, testOffset[compIdx].typeAuxInfo, invQuantOffset, blkStats[ctuRsAddr][compIdx][typeIdc]);

        //get rate
        m_CABACEstimator->getCtx() = SAOCtx( ctxStartLuma );
        m_CABACEstimator->resetBits();
        m_CABACEstimator->sao_offset_pars( testOffset[compIdx], compIdx, sliceEnabled[compIdx], bitDepths[CH_L] );
        double rate = FRAC_BITS_SCALE * m_CABACEstimator->getEstFracBits();
        cost = (double)dist[compIdx] + m_lambda[compIdx]*rate;
        if(cost < minCost)
        {
          minCost = cost;
          modeDist[compIdx] = dist[compIdx];
          modeParam[compIdx]= testOffset[compIdx];
          ctxBestLuma = SAOCtx( m_CABACEstimator->getCtx() );
        }
      }
    }
    m_CABACEstimator->getCtx() = SAOCtx( ctxBestLuma );
  }

  //------ chroma --------//
//"off" case as initial cost
  cost = 0;
  previousFracBits = 0;
  m_CABACEstimator->resetBits();
  for(uint32_t componentIndex = COMP_Cb; componentIndex < numberOfComponents; componentIndex++)
  {
    const ComponentID component = ComponentID(componentIndex);

    modeParam[component].modeIdc = SAO_MODE_OFF;
    modeDist [component]         = 0;
    m_CABACEstimator->sao_offset_pars( modeParam[component], component, sliceEnabled[component], bitDepths[CH_C] );
    const uint64_t currentFracBits = m_CABACEstimator->getEstFracBits();
    cost += m_lambda[component] * FRAC_BITS_SCALE * (currentFracBits - previousFracBits);
    previousFracBits = currentFracBits;
  }

  minCost = cost;

  //doesn't need to store cabac status here since the whole CTU parameters will be re-encoded at the end of this function

  for(int typeIdc=0; typeIdc< NUM_SAO_NEW_TYPES; typeIdc++)
  {
    m_CABACEstimator->getCtx() = SAOCtx( ctxBestLuma );
    m_CABACEstimator->resetBits();
    previousFracBits = 0;
    cost = 0;

    for(uint32_t componentIndex = COMP_Cb; componentIndex < numberOfComponents; componentIndex++)
    {
      const ComponentID component = ComponentID(componentIndex);
      if(!sliceEnabled[component])
      {
        testOffset[component].modeIdc = SAO_MODE_OFF;
        dist[component]= 0;
        continue;
      }
      testOffset[component].modeIdc = SAO_MODE_NEW;
      testOffset[component].typeIdc = typeIdc;

      //derive offset & get distortion
      deriveOffsets(component, bitDepths[CH_C], typeIdc, blkStats[ctuRsAddr][component][typeIdc], testOffset[component].offset, testOffset[component].typeAuxInfo);
      invertQuantOffsets(component, typeIdc, testOffset[component].typeAuxInfo, invQuantOffset, testOffset[component].offset);
      dist[component] = getDistortion(bitDepths[CH_C], typeIdc, testOffset[component].typeAuxInfo, invQuantOffset, blkStats[ctuRsAddr][component][typeIdc]);
      m_CABACEstimator->sao_offset_pars( testOffset[component], component, sliceEnabled[component], bitDepths[CH_C] );
      const uint64_t currentFracBits = m_CABACEstimator->getEstFracBits();
      cost += dist[component] + (m_lambda[component] * FRAC_BITS_SCALE * (currentFracBits - previousFracBits));
      previousFracBits = currentFracBits;
    }

    if(cost < minCost)
    {
      minCost = cost;
      for(uint32_t componentIndex = COMP_Cb; componentIndex < numberOfComponents; componentIndex++)
      {
        modeDist[componentIndex]  = dist[componentIndex];
        modeParam[componentIndex] = testOffset[componentIndex];
      }
    }

  } // SAO_TYPE loop

  //----- re-gen rate & normalized cost----//
  modeNormCost = 0;
  for(uint32_t componentIndex = COMP_Y; componentIndex < numberOfComponents; componentIndex++)
  {
    modeNormCost += (double)modeDist[componentIndex] / m_lambda[componentIndex];
  }

  m_CABACEstimator->getCtx() = SAOCtx( ctxStartBlk );
  m_CABACEstimator->resetBits();
  m_CABACEstimator->sao_block_pars( modeParam, bitDepths, sliceEnabled, (mergeList[SAO_MERGE_LEFT]!= NULL), (mergeList[SAO_MERGE_ABOVE]!= NULL), false );
  modeNormCost += FRAC_BITS_SCALE * m_CABACEstimator->getEstFracBits();
}

void EncSampleAdaptiveOffset::deriveModeMergeRDO(const BitDepths &bitDepths, int ctuRsAddr, SAOBlkParam* mergeList[NUM_SAO_MERGE_TYPES], const bool* sliceEnabled, const std::vector<SAOStatData**>& blkStats, SAOBlkParam& modeParam, double& modeNormCost )
{
  modeNormCost = MAX_DOUBLE;

  double cost;
  SAOBlkParam testBlkParam;
  const int numberOfComponents = m_numberOfComponents;

  const TempCtx ctxStart  ( m_CtxCache, SAOCtx( m_CABACEstimator->getCtx() ) );
  TempCtx       ctxBest   ( m_CtxCache );

  for(int mergeType=0; mergeType< NUM_SAO_MERGE_TYPES; mergeType++)
  {
    if(mergeList[mergeType] == NULL)
    {
      continue;
    }

    testBlkParam = *(mergeList[mergeType]);
    //normalized distortion
    double normDist=0;
    for(int compIdx = 0; compIdx < numberOfComponents; compIdx++)
    {
      testBlkParam[compIdx].modeIdc = SAO_MODE_MERGE;
      testBlkParam[compIdx].typeIdc = mergeType;

      SAOOffset& mergedOffsetParam = (*(mergeList[mergeType]))[compIdx];

      if( mergedOffsetParam.modeIdc != SAO_MODE_OFF)
      {
        //offsets have been reconstructed. Don't call inversed quantization function.
        normDist += (((double)getDistortion(bitDepths[toChannelType(ComponentID(compIdx))], mergedOffsetParam.typeIdc, mergedOffsetParam.typeAuxInfo, mergedOffsetParam.offset, blkStats[ctuRsAddr][compIdx][mergedOffsetParam.typeIdc]))
                       /m_lambda[compIdx] );
      }
    }

    //rate
    m_CABACEstimator->getCtx() = SAOCtx( ctxStart );
    m_CABACEstimator->resetBits();
    m_CABACEstimator->sao_block_pars( testBlkParam, bitDepths, sliceEnabled, (mergeList[SAO_MERGE_LEFT]!= NULL), (mergeList[SAO_MERGE_ABOVE]!= NULL), false );
    double rate = FRAC_BITS_SCALE * m_CABACEstimator->getEstFracBits();
    cost = normDist+rate;

    if(cost < modeNormCost)
    {
      modeNormCost = cost;
      modeParam    = testBlkParam;
      ctxBest      = SAOCtx( m_CABACEstimator->getCtx() );
    }
  }
  if( modeNormCost < MAX_DOUBLE )
  {
    m_CABACEstimator->getCtx() = SAOCtx( ctxBest );
  }
}

void EncSampleAdaptiveOffset::getBlkStats(const ComponentID compIdx, const int channelBitDepth, SAOStatData* statsDataTypes
                        , Pel* srcBlk, Pel* orgBlk, int srcStride, int orgStride, int width, int height
                        , bool isLeftAvail,  bool isRightAvail, bool isAboveAvail, bool isBelowAvail, bool isAboveLeftAvail, bool isAboveRightAvail )
{
  int x, startX, startY, endX, endY, edgeType, firstLineStartX, firstLineEndX;
  int64_t *diff, *count;
  Pel* srcLine, *orgLine;
  const int skipLinesR = compIdx == COMP_Y ? 5 : 3;
  const int skipLinesB = compIdx == COMP_Y ? 4 : 2;

  for(int typeIdx=0; typeIdx< NUM_SAO_NEW_TYPES; typeIdx++)
  {
    SAOStatData& statsData= statsDataTypes[typeIdx];
    statsData.reset();
    srcLine = srcBlk;
    orgLine = orgBlk;
    diff    = statsData.diff;
    count   = statsData.count;
    switch(typeIdx)
    {
    case SAO_TYPE_EO_0:
      {
        endY   =  isBelowAvail ? (height - skipLinesB) : height;
        startX = (isLeftAvail  ? 0 : 1);
        endX   = (isRightAvail ? (width - skipLinesR) : (width - 1));
        calcSaoStatisticsEo0(width,startX,endX,endY,srcLine,orgLine,srcStride,orgStride,count,diff);
      }
      break;
    case SAO_TYPE_EO_90:
      {
        int8_t *signUpLine = &m_signLineBuf1[0];
        startX = 0;
        startY = isAboveAvail ? 0 : 1;
        endX   = (isRightAvail ? (width - skipLinesR) : width);
        endY   = isBelowAvail ? (height - skipLinesB) : (height - 1);
        if (!isAboveAvail)
        {
          srcLine += srcStride;
          orgLine += orgStride;
        }
        calcSaoStatisticsEo90(width,endX,startY,endY,srcLine,orgLine,srcStride,orgStride,count,diff,signUpLine);
      }
      break;
    case SAO_TYPE_EO_135:
      {
        diff +=2;
        count+=2;
        int8_t *signUpLine, *signDownLine;
        signUpLine  = &m_signLineBuf1[0];
        signDownLine= &m_signLineBuf2[0];
        startX = isLeftAvail  ? 0 : 1;
        endX   = isRightAvail ? (width - skipLinesR): (width - 1);
        endY   = isBelowAvail ? (height - skipLinesB) : (height - 1);
        //prepare 2nd line's upper sign
        Pel* srcLineBelow = srcLine + srcStride;
        for (x=startX; x<endX+1; x++)
        {
          signUpLine[x] = (int8_t)sgn(srcLineBelow[x] - srcLine[x-1]);
        }
        //1st line
        Pel* srcLineAbove = srcLine - srcStride;
        firstLineStartX = isAboveLeftAvail ? 0    : 1;
        firstLineEndX   = isAboveAvail     ? endX : 1;
        for(x=firstLineStartX; x<firstLineEndX; x++)
        {
          edgeType = sgn(srcLine[x] - srcLineAbove[x-1]) - signUpLine[x+1];
          diff [edgeType] += (orgLine[x] - srcLine[x]);
          count[edgeType] ++;
        }
        srcLine  += srcStride;
        orgLine  += orgStride;
        calcSaoStatisticsEo135(width,startX,endX,endY,srcLine,orgLine,srcStride,orgStride,count,diff,signUpLine,signDownLine);
      }
      break;
    case SAO_TYPE_EO_45:
      {
        diff +=2;
        count+=2;
        int8_t *signUpLine = &m_signLineBuf1[1];

        startX = isLeftAvail  ? 0 : 1;
        endX   = isRightAvail ? (width - skipLinesR) : (width - 1);
        endY   = isBelowAvail ? (height - skipLinesB) : (height - 1);

        //prepare 2nd line upper sign
        Pel* srcLineBelow = srcLine + srcStride;
        for (x=startX-1; x<endX; x++)
        {
          signUpLine[x] = (int8_t)sgn(srcLineBelow[x] - srcLine[x+1]);
        }
        //first line
        Pel* srcLineAbove = srcLine - srcStride;
        firstLineStartX = isAboveAvail ? startX : endX;
        firstLineEndX   = (!isRightAvail && isAboveRightAvail) ? width : endX;
        for(x=firstLineStartX; x<firstLineEndX; x++)
        {
          edgeType = sgn(srcLine[x] - srcLineAbove[x+1]) - signUpLine[x-1];
          diff [edgeType] += (orgLine[x] - srcLine[x]);
          count[edgeType] ++;
        }
        srcLine += srcStride;
        orgLine += orgStride;
        calcSaoStatisticsEo45(width,startX,endX,endY,srcLine,orgLine,srcStride,orgStride,count,diff,signUpLine);
      }
      break;
    case SAO_TYPE_BO:
      {
        startX = 0;
        endX   = isRightAvail ? (width - skipLinesR) : width;
        endY   = isBelowAvail ? (height- skipLinesB) : height;
        calcSaoStatisticsBo(width,endX,endY,srcLine,orgLine,srcStride,orgStride,channelBitDepth,count,diff);
      }
      break;
    default:
      {
        THROW("Not a supported SAO type");
      }
    }
  }
}

void EncSampleAdaptiveOffset::deriveLoopFilterBoundaryAvailibility(CodingStructure& cs, const Position& pos, bool& isLeftAvail, bool& isAboveAvail, bool& isAboveLeftAvail) const
{
  const bool isLoopFiltAcrossSlicePPS = cs.pps->loopFilterAcrossSlicesEnabled;
  const bool isLoopFiltAcrossTilePPS = cs.pps->loopFilterAcrossTilesEnabled;

  const int width = cs.pcv->maxCUSize;
  const int height = cs.pcv->maxCUSize;
  const CodingUnit* cuCurr = cs.getCU(pos, CH_L, TREE_D);
  const int ctuX = pos.x >> cs.pcv->maxCUSizeLog2;
  const int ctuY = pos.y >> cs.pcv->maxCUSizeLog2;
  const PPS* pps = cs.slice->pps;
  const CodingUnit* cuLeft      = ctuX > 0 &&             pps->canFilterCtuBdry( ctuX, ctuY, -1, 0 ) ? cs.getCU(pos.offset(-width, 0), CH_L, TREE_D): nullptr;
  const CodingUnit* cuAbove     = ctuY > 0 &&             pps->canFilterCtuBdry( ctuX, ctuY, 0, -1 ) ? cs.getCU(pos.offset(0, -height), CH_L, TREE_D): nullptr;
  const CodingUnit* cuAboveLeft = ctuY > 0 && ctuX > 0 && pps->canFilterCtuBdry( ctuX, ctuY, -1,-1 ) ? cs.getCU(pos.offset(-width, -height), CH_L, TREE_D): nullptr;

  if (!isLoopFiltAcrossSlicePPS)
  {
    isLeftAvail      = (cuLeft == NULL)      ? false : CU::isSameSlice(*cuCurr, *cuLeft);
    isAboveAvail     = (cuAbove == NULL)     ? false : CU::isSameSlice(*cuCurr, *cuAbove);
    isAboveLeftAvail = (cuAboveLeft == NULL) ? false : CU::isSameSlice(*cuCurr, *cuAboveLeft);
  }
  else
  {
    isLeftAvail      = (cuLeft != NULL);
    isAboveAvail     = (cuAbove != NULL);
    isAboveLeftAvail = (cuAboveLeft != NULL);
  }

  if (!isLoopFiltAcrossTilePPS)
  {
    isLeftAvail      = (!isLeftAvail)      ? false : CU::isSameTile(*cuCurr, *cuLeft);
    isAboveAvail     = (!isAboveAvail)     ? false : CU::isSameTile(*cuCurr, *cuAbove);
    isAboveLeftAvail = (!isAboveLeftAvail) ? false : CU::isSameTile(*cuCurr, *cuAboveLeft);
  }


  SubPic curSubPic = cs.pps->getSubPicFromCU(*cuCurr);
  if (!curSubPic.loopFilterAcrossSubPicEnabled )
  {
    isLeftAvail      = (!isLeftAvail)      ? false : CU::isSameSubPic(*cuCurr, *cuLeft);
    isAboveAvail     = (!isAboveAvail)     ? false : CU::isSameSubPic(*cuCurr, *cuAbove);
    isAboveLeftAvail = (!isAboveLeftAvail) ? false : CU::isSameSubPic(*cuCurr, *cuAboveLeft);
  }

}

} // namespace vvenc

//! \}


Coverage Report

Created: 2026-10-28 06:18