/** Calculate SAO statistics for current LCU
* \param iAddr, iPartIdx, iYCbCr
*/
Void TEncSampleAdaptiveOffset::calcSaoStatsCu(Int iAddr, Int iPartIdx, Int iYCbCr)
{
if(!m_bUseNIF) //!< true for performing non-cross slice boundary ALF
{
calcSaoStatsCuOrg( iAddr, iPartIdx, iYCbCr);
}
else
{
Int64** ppStats = m_iOffsetOrg[iPartIdx]; //!< [MAX_NUM_SAO_PART][MAX_NUM_SAO_TYPE][MAX_NUM_SAO_CLASS] ??
Int64** ppCount = m_iCount [iPartIdx]; //!< [MAX_NUM_SAO_PART][MAX_NUM_SAO_TYPE][MAX_NUM_SAO_CLASS]
//parameters
Int isChroma = (iYCbCr != 0)? 1:0;
Int stride = (iYCbCr != 0)?(m_pcPic->getCStride()):(m_pcPic->getStride());
Pel* pPicOrg = getPicYuvAddr (m_pcPic->getPicYuvOrg(), iYCbCr);
Pel* pPicRec = getPicYuvAddr(m_pcYuvTmp, iYCbCr);
std::vector<NDBFBlockInfo>& vFilterBlocks = *(m_pcPic->getCU(iAddr)->getNDBFilterBlocks());
//variables
UInt xPos, yPos, width, height;
Bool* pbBorderAvail;
UInt posOffset;
for(Int i=0; i< vFilterBlocks.size(); i++)
{
xPos = vFilterBlocks[i].posX >> isChroma;
yPos = vFilterBlocks[i].posY >> isChroma;
width = vFilterBlocks[i].width >> isChroma;
height = vFilterBlocks[i].height >> isChroma;
pbBorderAvail = vFilterBlocks[i].isBorderAvailable;
posOffset = (yPos* stride) + xPos;
//! 对ppStats，ppCount赋值，分别计算出对应滤波模式下原始像素与重建像素之间的差值，重建值对应的classIdx的统计值
calcSaoStatsBlock(pPicRec+ posOffset, pPicOrg+ posOffset, stride, ppStats, ppCount,width, height, pbBorderAvail, iYCbCr);
}
}
}
/** Calculate SAO statistics for non-cross-slice or non-cross-tile processing
* \param pRecStart to-be-filtered block buffer pointer
* \param pOrgStart original block buffer pointer
* \param stride picture buffer stride
* \param ppStat statistics buffer
* \param ppCount counter buffer
* \param width block width
* \param height block height
* \param pbBorderAvail availabilities of block border pixels
*/
Void TEncSampleAdaptiveOffset::calcSaoStatsBlock( Pel* pRecStart, Pel* pOrgStart, Int stride, Int64** ppStats, Int64** ppCount, UInt width, UInt height, Bool* pbBorderAvail, Int iYCbCr)
{
Int64 *stats, *count;
Int classIdx, posShift, startX, endX, startY, endY, signLeft,signRight,signDown,signDown1;
Pel *pOrg, *pRec;
UInt edgeType;
Int x, y;
Pel *pTableBo = (iYCbCr==0)?m_lumaTableBo:m_chromaTableBo; //!< band offset 的索引表，共32个bands
//--------- Band offset-----------//
stats = ppStats[SAO_BO];
count = ppCount[SAO_BO];
pOrg = pOrgStart;
pRec = pRecStart;
for (y=0; y< height; y++)
{
for (x=0; x< width; x++)
{
classIdx = pTableBo[pRec[x]]; //!< classIdx即查表得到的band对应的序号值（1~32）
if (classIdx)
{
stats[classIdx] += (pOrg[x] - pRec[x]); //!< 对原始像素与重建像素的差值求和
count[classIdx] ++; //!< 对应classIdx的统计值加1
}
}
pOrg += stride;
pRec += stride;
}
//---------- Edge offset 0--------------//
stats = ppStats[SAO_EO_0];
count = ppCount[SAO_EO_0];
pOrg = pOrgStart;
pRec = pRecStart;
//!< 设置起始点和终点
startX = (pbBorderAvail[SGU_L]) ? 0 : 1;
endX = (pbBorderAvail[SGU_R]) ? width : (width -1);
for (y=0; y< height; y++)
{
signLeft = xSign(pRec[startX] - pRec[startX-1]); //!< 取 p - n0 的符号
for (x=startX; x< endX; x++)
{
signRight = xSign(pRec[x] - pRec[x+1]); //!< 取 p - n1 的符号
edgeType = signRight + signLeft + 2; //!< 计算符号类型，用于下面通过查表的方式确定EdgeIdx
signLeft = -signRight;
/*
const UInt TComSampleAdaptiveOffset::m_auiEoTable[9] =
{
1, //0
2, //1
0, //2
3, //3
4, //4
0, //5
0, //6
0, //7
0
};
*/
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]); //!< 通过查表可以确定出真正的EdgeIdx，从而把统计值保存到对应的类型中去
count[m_auiEoTable[edgeType]] ++;
}
pRec += stride;
pOrg += stride;
}
//---------- Edge offset 1--------------//
stats = ppStats[SAO_EO_1];
count = ppCount[SAO_EO_1];
pOrg = pOrgStart;
pRec = pRecStart;
startY = (pbBorderAvail[SGU_T]) ? 0 : 1;
endY = (pbBorderAvail[SGU_B]) ? height : height-1;
if (!pbBorderAvail[SGU_T]) //!< 如果上邻行不可用，则下移一行
{
pRec += stride;
pOrg += stride;
}
for (x=0; x< width; x++) //!< 先计算第一行与其上一行的差值
{
m_iUpBuff1[x] = xSign(pRec[x] - pRec[x-stride]); //!< 保存整一行 p - n0 的符号
}
for (y=startY; y<endY; y++)
{
for (x=0; x< width; x++)
{
signDown = xSign(pRec[x] - pRec[x+stride]); //!< 取 p - n1 的符号
edgeType = signDown + m_iUpBuff1[x] + 2;
m_iUpBuff1[x] = -signDown; //!< -signDown相当于是下一行的 p - n0 的符号，保存下来
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
}
pOrg += stride;
pRec += stride;
}
//---------- Edge offset 2--------------//
stats = ppStats[SAO_EO_2];
count = ppCount[SAO_EO_2];
pOrg = pOrgStart;
pRec = pRecStart;
posShift= stride + 1;
startX = (pbBorderAvail[SGU_L]) ? 0 : 1 ;
endX = (pbBorderAvail[SGU_R]) ? width : (width-1);
//prepare 2nd line upper sign
pRec += stride;
for (x=startX; x< endX+1; x++) //!< 先计算第二行的 p - n0 的符号，并保存下来
{
m_iUpBuff1[x] = xSign(pRec[x] - pRec[x- posShift]);
}
//1st line
pRec -= stride; //!< 回到第一行
if(pbBorderAvail[SGU_TL]) //!< Top Left available
{
x= 0;
edgeType = xSign(pRec[x] - pRec[x- posShift]) - m_iUpBuff1[x+1] + 2; //!< -m_iUpBuff1[x+1]是因为第二行的p - n0相当于第一行的n1 - p，且第二行的x+1的位置才是第一行的x位置
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
}
if(pbBorderAvail[SGU_T]) //!< Top available
{
for(x= 1; x< endX; x++)
{
edgeType = xSign(pRec[x] - pRec[x- posShift]) - m_iUpBuff1[x+1] + 2;
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
}
}
pRec += stride;
pOrg += stride;
//middle lines
for (y= 1; y< height-1; y++) //!< 除了第一行和最后一行的行
{
for (x=startX; x<endX; x++)
{
signDown1 = xSign(pRec[x] - pRec[x+ posShift]) ; //!< 取 p - n1 的符号
edgeType = signDown1 + m_iUpBuff1[x] + 2; //!< 此时m_iUpBuff1[x]正好就是p - n0 的符号
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
m_iUpBufft[x+1] = -signDown1; //!< 当前行的p - n1相当于下一行的p - n0 的相反数，且当前行的x，对应于下一行的x+1
}
m_iUpBufft[startX] = xSign(pRec[stride+startX] - pRec[startX-1]); //!< 取startX位置的p - n0的符号
//!< m_iUpBuff1与m_iUpBufft交换，交换完成后，m_iUpBuff1将保存的是下一行的p - n0的符号
ipSwap = m_iUpBuff1;
m_iUpBuff1 = m_iUpBufft;
m_iUpBufft = ipSwap;
pRec += stride;
pOrg += stride;
}
//last line
if(pbBorderAvail[SGU_B]) //!< 最后一行，Bottom available
{
for(x= startX; x< width-1; x++)
{
edgeType = xSign(pRec[x] - pRec[x+ posShift]) + m_iUpBuff1[x] + 2; //!< 此时m_iUpBuff1保存的就是最后一行的p - n0的符号
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
}
}
if(pbBorderAvail[SGU_BR]) //!< Bottom Right available
{
x= width -1;
edgeType = xSign(pRec[x] - pRec[x+ posShift]) + m_iUpBuff1[x] + 2;
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
}
//---------- Edge offset 3--------------//
stats = ppStats[SAO_EO_3];
count = ppCount[SAO_EO_3];
pOrg = pOrgStart;
pRec = pRecStart;
posShift = stride - 1;
startX = (pbBorderAvail[SGU_L]) ? 0 : 1;
endX = (pbBorderAvail[SGU_R]) ? width : (width -1);
//prepare 2nd line upper sign
pRec += stride;
for (x=startX-1; x< endX; x++) //!< 先算第二行的p - n0的符号并保存到m_iUpBuff1中
{
m_iUpBuff1[x] = xSign(pRec[x] - pRec[x- posShift]);
}
//first line
pRec -= stride; //!< 回到第一行
if(pbBorderAvail[SGU_T]) //!< Top available
{
for(x= startX; x< width -1; x++)
{
edgeType = xSign(pRec[x] - pRec[x- posShift]) -m_iUpBuff1[x-1] + 2;//!< -m_iUpBuff1[x-1]是因为第二行的p - n0相当于第一行的n1 - p，且第二行的x-1的位置才是第一行的x位置
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
}
}
if(pbBorderAvail[SGU_TR]) //!< Top Right available
{
x= width-1;
edgeType = xSign(pRec[x] - pRec[x- posShift]) -m_iUpBuff1[x-1] + 2;
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
}
pRec += stride;
pOrg += stride;
//middle lines
for (y= 1; y< height-1; y++) //!< 除第一行和最后一行的行
{
for(x= startX; x< endX; x++)
{
signDown1 = xSign(pRec[x] - pRec[x+ posShift]) ;
edgeType = signDown1 + m_iUpBuff1[x] + 2; //!< 此时m_iUpBuff1就是当前行的p - n0的符号
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
m_iUpBuff1[x-1] = -signDown1; //!< 当前行的p - n1相当于下一行的p - n0 的相反数，且当前行的x，对应于下一行的x-1
}
m_iUpBuff1[endX-1] = xSign(pRec[endX-1 + stride] - pRec[endX]); //!< 保存下一行endX-1处的p - n0的符号
pRec += stride;
pOrg += stride;
}
//last line
if(pbBorderAvail[SGU_BL]) //!< Bottom Left available
{
x= 0;
edgeType = xSign(pRec[x] - pRec[x+ posShift]) + m_iUpBuff1[x] + 2; //!< 此时m_iUpBuff1正好保存的是最后一行的x位置的p - n0的符号
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
}
if(pbBorderAvail[SGU_B]) //!< Bottom available
{
for(x= 1; x< endX; x++)
{
edgeType = xSign(pRec[x] - pRec[x+ posShift]) + m_iUpBuff1[x] + 2;
stats[m_auiEoTable[edgeType]] += (pOrg[x] - pRec[x]);
count[m_auiEoTable[edgeType]] ++;
}
}
}
