x265-1.7版本-common/slice.cpp注释

注：问号以及未注释部分 会在x265-1.8版本内更新

/***************************************************************************** * Copyright (C) 2015 x265 project * * Authors: Steve Borho <[e-mail]> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111, USA. * * This program is also available under a commercial proprietary license. * For more information, contact us at license @ x265.com. *****************************************************************************/#include "common.h"#include "frame.h"#include "piclist.h"#include "picyuv.h"#include "slice.h"using namespace x265;/** 函数功能       ： 获取参考帧List 以及 POC/*  调用范围       ： 只在DPB::prepareEncode函数中被调用* \参数 picList    ： DPB m_picList*   返回值         ： null**/void Slice::setRefPicList(PicList& picList){    if (m_sliceType == I_SLICE)    {        memset(m_refPicList, 0, sizeof(m_refPicList)); //I帧 无参考帧，全部置为0        m_numRefIdx[1] = m_numRefIdx[0] = 0;        return;    }    Frame* refPic = NULL;//临时变量 用于获取参考帧    Frame* refPicSetStCurr0[MAX_NUM_REF];//存储前向帧 指针    Frame* refPicSetStCurr1[MAX_NUM_REF];//存储后向帧 指针    Frame* refPicSetLtCurr[MAX_NUM_REF];//存储长期参考帧  （x265没有应用）    int numPocStCurr0 = 0;//计数前向帧个数    int numPocStCurr1 = 0;//计数后向帧个数    int numPocLtCurr = 0;//计数long-term 参考帧 （x265没有应用）    int i;//临时变量 用于计数    for (i = 0; i < m_rps.numberOfNegativePictures; i++)//获取前向参考帧    {        if (m_rps.bUsed[i])        {            refPic = picList.getPOC(m_poc + m_rps.deltaPOC[i]);            refPicSetStCurr0[numPocStCurr0] = refPic;            numPocStCurr0++;        }    }    for (; i < m_rps.numberOfNegativePictures + m_rps.numberOfPositivePictures; i++)//获取后向参考帧    {        if (m_rps.bUsed[i])        {            refPic = picList.getPOC(m_poc + m_rps.deltaPOC[i]);            refPicSetStCurr1[numPocStCurr1] = refPic;            numPocStCurr1++;        }    }    X265_CHECK(m_rps.numberOfPictures == m_rps.numberOfNegativePictures + m_rps.numberOfPositivePictures,               "unexpected picture in RPS\n");    // ref_pic_list_init    Frame* rpsCurrList0[MAX_NUM_REF + 1];//存储List0    Frame* rpsCurrList1[MAX_NUM_REF + 1];//存储List1    int numPocTotalCurr = numPocStCurr0 + numPocStCurr1 + numPocLtCurr;//参考着个数    int cIdx = 0;    //将前向帧和后向帧已经长期参考帧全部存入List0    for (i = 0; i < numPocStCurr0; i++, cIdx++)        rpsCurrList0[cIdx] = refPicSetStCurr0[i];    for (i = 0; i < numPocStCurr1; i++, cIdx++)        rpsCurrList0[cIdx] = refPicSetStCurr1[i];    for (i = 0; i < numPocLtCurr; i++, cIdx++)        rpsCurrList0[cIdx] = refPicSetLtCurr[i];    X265_CHECK(cIdx == numPocTotalCurr, "RPS index check fail\n");    if (m_sliceType == B_SLICE)    {        cIdx = 0;        //将后向帧和前向帧已经长期参考帧全部存入List0        for (i = 0; i < numPocStCurr1; i++, cIdx++)            rpsCurrList1[cIdx] = refPicSetStCurr1[i];        for (i = 0; i < numPocStCurr0; i++, cIdx++)            rpsCurrList1[cIdx] = refPicSetStCurr0[i];        for (i = 0; i < numPocLtCurr; i++, cIdx++)            rpsCurrList1[cIdx] = refPicSetLtCurr[i];        X265_CHECK(cIdx == numPocTotalCurr, "RPS index check fail\n");    }    //存储实际List0列表值    for (int rIdx = 0; rIdx < m_numRefIdx[0]; rIdx++)    {        cIdx = rIdx % numPocTotalCurr;        X265_CHECK(cIdx >= 0 && cIdx < numPocTotalCurr, "RPS index check fail\n");        m_refPicList[0][rIdx] = rpsCurrList0[cIdx];    }    if (m_sliceType != B_SLICE)    {        m_numRefIdx[1] = 0;        memset(m_refPicList[1], 0, sizeof(m_refPicList[1]));//不是B帧 ，将后向List置为0    }    else    {        for (int rIdx = 0; rIdx < m_numRefIdx[1]; rIdx++)        {            //存储实际List1列表值            cIdx = rIdx % numPocTotalCurr;            X265_CHECK(cIdx >= 0 && cIdx < numPocTotalCurr, "RPS index check fail\n");            m_refPicList[1][rIdx] = rpsCurrList1[cIdx];        }    }    //获取参考帧POC    for (int dir = 0; dir < 2; dir++)        for (int numRefIdx = 0; numRefIdx < m_numRefIdx[dir]; numRefIdx++)            m_refPOCList[dir][numRefIdx] = m_refPicList[dir][numRefIdx]->m_poc;}/** 函数功能           ： 关闭当前帧的加权预测/*  调用范围           ： 只在Slice()、FrameEncoder::compressFrame()、weightAnalyse函数中被调用*   返回值             ： null**/void Slice::disableWeights(){    for (int l = 0; l < 2; l++)        for (int i = 0; i < MAX_NUM_REF; i++)            for (int yuv = 0; yuv < 3; yuv++)            {                WeightParam& wp = m_weightPredTable[l][i][yuv];                wp.bPresentFlag = false;                wp.log2WeightDenom = 0;                wp.inputWeight = 1;                wp.inputOffset = 0;            }}/* Sorts the deltaPOC and Used by current values in the RPS based on the * deltaPOC values.  deltaPOC values are sorted with -ve values before the +ve * values.  -ve values are in decreasing order.  +ve values are in increasing * order *//** 函数功能           ： 将RPS列表中的deltaPOC和bused 按照 远 近 （当前帧） 近 远的次序排序/*  调用范围           ： 只在DPB::computeRPS函数中被调用*   返回值             ： null**/void RPS::sortDeltaPOC(){    // sort in increasing order (smallest first)    for (int j = 1; j < numberOfPictures; j++)  //将deltaPoc按照从小到大排序（即，按照poc的顺序从小到大排序）    {        int dPOC = deltaPOC[j];        bool used = bUsed[j];        for (int k = j - 1; k >= 0; k--)        {            int temp = deltaPOC[k];            if (dPOC < temp)            {                deltaPOC[k + 1] = temp;                bUsed[k + 1] = bUsed[k];                deltaPOC[k] = dPOC;                bUsed[k] = used;            }        }    }    // flip the negative values to largest first    int numNegPics = numberOfNegativePictures;//获取前向帧个数    for (int j = 0, k = numNegPics - 1; j < numNegPics >> 1; j++, k--)//将前向帧按照由远即近排序    {        int dPOC = deltaPOC[j];        bool used = bUsed[j];        deltaPOC[j] = deltaPOC[k];        bUsed[j] = bUsed[k];        deltaPOC[k] = dPOC;        bUsed[k] = used;    }}/** 函数功能       ： 返回一帧中最后实际像素在帧中的4x4块标号+1/*  调用范围       ： 只在Encoder::encode函数中被调用* \参数 endCUAddr  ： (一帧CTU个数)*（在CTU中4x4的个数）*   返回值         ： 返回一帧中最后实际像素在帧中的4x4块标号+1**/uint32_t Slice::realEndAddress(uint32_t endCUAddr) const{    // Calculate end address    uint32_t internalAddress = (endCUAddr - 1) % NUM_4x4_PARTITIONS;//最后一个CTU的最后一个4x4块在内部的标号    uint32_t externalAddress = (endCUAddr - 1) / NUM_4x4_PARTITIONS;//最后一个CTU在帧中的标号    uint32_t xmax = m_sps->picWidthInLumaSamples - (externalAddress % m_sps->numCuInWidth) * g_maxCUSize;//最后一个CTU的实际像素宽度上有多少像素（不含扩边）    uint32_t ymax = m_sps->picHeightInLumaSamples - (externalAddress / m_sps->numCuInWidth) * g_maxCUSize;//最后一个CTU的实际像素高度上有多少像素（不含扩边）    while (g_zscanToPelX[internalAddress] >= xmax || g_zscanToPelY[internalAddress] >= ymax)//找到实际像素右下角的4x4的zigzag标号        internalAddress--;    internalAddress++;//因为是从0开始计数，这样加一看看是否充满整个CTU的4x4个数 （这里可以理解为最后一个CTU含有多少实际的4x4块个数）    if (internalAddress == NUM_4x4_PARTITIONS)//如果最后一个CTU是一个完成的CTU    {        internalAddress = 0;//内部编号为0        externalAddress++;  //因为是从0开始计数，这里表示一帧含有多少个（充满状态）CTU    }    return externalAddress * NUM_4x4_PARTITIONS + internalAddress;//返回一帧中最后实际像素在帧中的4x4块标号+1}