Function PredictSadSkip

codec/encoder/core/src/md.cpp:870–909

void PredictSadSkip (int8_t* pRefIndexCache, bool* pMbSkipCache, int32_t* pSadCostCache, int32_t uiRef,
                     int32_t* iSadPredSkip) {
  const int32_t kiRefB  = pRefIndexCache[1];//top g_uiCache12_8x8RefIdx[0] - 4
  int32_t iRefC         = pRefIndexCache[5];//top-right g_uiCache12_8x8RefIdx[0] - 2
  const int32_t kiRefA  = pRefIndexCache[6];//left g_uiCache12_8x8RefIdx[0] - 1
  const int32_t kiSadB  = (pMbSkipCache[1] == 1 ? pSadCostCache[1] : 0);
  int32_t iSadC         = (pMbSkipCache[2] == 1 ? pSadCostCache[2] : 0);
  const int32_t kiSadA  = (pMbSkipCache[3] == 1 ? pSadCostCache[3] : 0);
  int32_t iRefSkip      = pMbSkipCache[2];

  int32_t iCount = 0;

  if (iRefC == REF_NOT_AVAIL) {
    iRefC = pRefIndexCache[0];//top-left g_uiCache12_8x8RefIdx[0] - 4 - 1
    iSadC  = (pMbSkipCache[0] == 1 ? pSadCostCache[0] : 0);
    iRefSkip = pMbSkipCache[0];
  }

  if (kiRefB == REF_NOT_AVAIL && iRefC == REF_NOT_AVAIL && kiRefA != REF_NOT_AVAIL) {
    * iSadPredSkip = kiSadA;
  } else {
    iCount  = ((uiRef == kiRefA) && (pMbSkipCache[3] == 1)) << MB_LEFT_BIT;
    iCount |= ((uiRef == kiRefB) && (pMbSkipCache[1] == 1)) << MB_TOP_BIT;
    iCount |= ((uiRef == iRefC) && (iRefSkip == 1)) << MB_TOPRIGHT_BIT;
    switch (iCount) {
    case LEFT_MB_POS:// A
      *iSadPredSkip = kiSadA;
      break;
    case TOP_MB_POS:// B
      *iSadPredSkip = kiSadB;
      break;
    case TOPRIGHT_MB_POS:// C or D
      *iSadPredSkip = iSadC;
      break;
    default:
      *iSadPredSkip = WelsMedian (kiSadA, kiSadB, iSadC);
      break;
    }
  }
}
}