[cpp]

Bool TComDataCU::xGetColMVP( RefPicList eRefPicList, Int uiCUAddr, Int uiPartUnitIdx, TComMv& rcMv, Int& riRefIdx )

{//! 这部分的内容可以参考draft 8.5.2.1.7, Derivation process for temporal luma motion vector prediction

//! 这个函数的返回条件可以参考该部分的第3小点，The variables mvLXCol and availableFlagLXCol are derived as follows ...

UInt uiAbsPartAddr = uiPartUnitIdx;

RefPicList eColRefPicList;

Int iColPOC, iColRefPOC, iCurrPOC, iCurrRefPOC, iScale;

TComMv cColMv;

// use coldir.

//! Colocated Picture

TComPic *pColPic = getSlice()->getRefPic( RefPicList(getSlice()->isInterB() 1-getSlice()->getColFromL0Flag() : 0), getSlice()->getColRefIdx());

//! Colocated CU

TComDataCU *pColCU = pColPic->getCU( uiCUAddr );

if(pColCU->getPic()==0||pColCU->getPartitionSize(uiPartUnitIdx)==SIZE_NONE) //!< Colocated Picture or colocated CU不存在

{

return false;

}

iCurrPOC = m_pcSlice->getPOC(); //!< 当前slice的POC

iCurrRefPOC = m_pcSlice->getRefPic(eRefPicList, riRefIdx)->getPOC(); //!< 当前slice参考帧的POC

iColPOC = pColCU->getSlice()->getPOC(); //!< 当前slice的colocated picuture的POC

if (pColCU->isIntra(uiAbsPartAddr)) //!< colocated CU为帧内预测模式，即没有MV，故直接返回false

{

return false;

}

eColRefPicList = getSlice()->getCheckLDC() eRefPicList : RefPicList(getSlice()->getColFromL0Flag());

Int iColRefIdx = pColCU->getCUMvField(RefPicList(eColRefPicList))->getRefIdx(uiAbsPartAddr); //!< colocated CU对应的参考帧的序号

if (iColRefIdx < 0 )

{

eColRefPicList = RefPicList(1 - eColRefPicList);

iColRefIdx = pColCU->getCUMvField(RefPicList(eColRefPicList))->getRefIdx(uiAbsPartAddr);

if (iColRefIdx < 0 )

{

return false;

}

}

// Scale the vector.

iColRefPOC = pColCU->getSlice()->getRefPOC(eColRefPicList, iColRefIdx);

cColMv = pColCU->getCUMvField(eColRefPicList)->getMv(uiAbsPartAddr);

iCurrRefPOC = m_pcSlice->getRefPic(eRefPicList, riRefIdx)->getPOC();

Bool bIsCurrRefLongTerm = m_pcSlice->getRefPic(eRefPicList, riRefIdx)->getIsLongTerm();

Bool bIsColRefLongTerm = pColCU->getSlice()->getRefPic(eColRefPicList, iColRefIdx)->getIsUsedAsLongTerm();

if ( bIsCurrRefLongTerm != bIsColRefLongTerm )

{

return false;

}

if ( bIsCurrRefLongTerm || bIsColRefLongTerm )

{

rcMv = cColMv; //!< draft 式子(8-155)

}

else

{

iScale = xGetDistScaleFactor(iCurrPOC, iCurrRefPOC, iColPOC, iColRefPOC); //!< 接下来分析

if ( iScale == 4096 )

{

rcMv = cColMv;

}

else

{

rcMv = cColMv.scaleMv( iScale ); //!< draft 式子(8-158)

}

}

return true;

}

[cpp]

Int TComDataCU::xGetDistScaleFactor(Int iCurrPOC, Int iCurrRefPOC, Int iColPOC, Int iColRefPOC)

{

Int iDiffPocD = iColPOC - iColRefPOC; //!< draft 式子(8-159)

Int iDiffPocB = iCurrPOC - iCurrRefPOC; //!< draft 式子(8-160)

if( iDiffPocD == iDiffPocB )

{

return 4096;

}

else

{ www.2cto.com

Int iTDB = Clip3( -128, 127, iDiffPocB );

Int iTDD = Clip3( -128, 127, iDiffPocD );

Int iX = (0x4000 + abs(iTDD/2)) / iTDD; //!< draft 式子(8-156)

Int iScale = Clip3( -4096, 4095, (iTDB * iX + 32) >> 6 ); //!< draft 式子(8-157)

return iScale;

}

}

[cpp]

const TComMv scaleMv( Int iScale ) const

{//! draft 式子(8-158)

Int mvx = Clip3( -32768, 32767, (iScale * getHor() + 127 + (iScale * getHor() < 0)) >> 8 );