代码跟踪

（1）HM代码入口：main函数  encmain。找到main函数中调用的函数。再继续走下去

 // call encoding function  <span style="color:#ff0000;">cTAppEncTop.encode()</span>;//cTAppEncTop时TAppEncTop的对象，该语句的含义是调用成员函数。。encode是类TAppEncTop的成员函数  // ending time  dResult = (Double)(clock()-lBefore) / CLOCKS_PER_SEC;  printf("\n Total Time: %12.3f sec.\n", dResult);  // destroy application encoder class  cTAppEncTop.destroy();  return 0;}

这里调用了TAppEncTop.cpp中定义的一个函数

cTAppEncTop.encode()

（2）转到TAppEncTop.cpp中，查看函数encode的定义

Void TAppEncTop::encode(){  fstream bitstreamFile(m_pchBitstreamFile, fstream::binary | fstream::out);  if (!bitstreamFile)  {    fprintf(stderr, "\nfailed to open bitstream file `%s' for writing\n", m_pchBitstreamFile);//    exit(EXIT_FAILURE);  }  TComPicYuv*       pcPicYuvOrg = new TComPicYuv;  TComPicYuv*       pcPicYuvRec = NULL;  // initialize internal class & member variables  xInitLibCfg();//都是类中函数调用类中的函数  xCreateLib();//TAppEncTop的成员函数  xInitLib(m_isField);  printChromaFormat();  // main encoder loop主编码函数环路  Int   iNumEncoded = 0;  Bool  bEos = false;  const InputColourSpaceConversion ipCSC  =  m_inputColourSpaceConvert;  const InputColourSpaceConversion snrCSC = (!m_snrInternalColourSpace) ? m_inputColourSpaceConvert : IPCOLOURSPACE_UNCHANGED;  list<AccessUnit> outputAccessUnits; ///< list of access units to write out.  is populated by the encoding process  TComPicYuv cPicYuvTrueOrg;  // allocate original YUV buffer分配原始YUV缓冲器  if( m_isField )  {    pcPicYuvOrg->create( m_iSourceWidth, m_iSourceHeightOrg, m_chromaFormatIDC, m_uiMaxCUWidth, m_uiMaxCUHeight, m_uiMaxCUDepth );  cPicYuvTrueOrg.create(m_iSourceWidth, m_iSourceHeightOrg, m_chromaFormatIDC, m_uiMaxCUWidth, m_uiMaxCUHeight, m_uiMaxCUDepth);  }  else  {    pcPicYuvOrg->create( m_iSourceWidth, m_iSourceHeight, m_chromaFormatIDC, m_uiMaxCUWidth, m_uiMaxCUHeight, m_uiMaxCUDepth );  cPicYuvTrueOrg.create(m_iSourceWidth, m_iSourceHeight, m_chromaFormatIDC, m_uiMaxCUWidth, m_uiMaxCUHeight, m_uiMaxCUDepth);  }  while ( !bEos )  {    // get buffers    xGetBuffer(pcPicYuvRec);    // read input YUV file    m_cTVideoIOYuvInputFile.read( pcPicYuvOrg, &cPicYuvTrueOrg, ipCSC, m_aiPad, m_InputChromaFormatIDC );    // increase number of received frames    m_iFrameRcvd++;//总的帧数增加    bEos = (m_isField && (m_iFrameRcvd == (m_framesToBeEncoded >> 1) )) || ( !m_isField && (m_iFrameRcvd == m_framesToBeEncoded) );    Bool flush = 0;    // if end of file (which is only detected on a read failure) flush the encoder of any queued pictures    if (m_cTVideoIOYuvInputFile.isEof())    {      flush = true;      bEos = true;      m_iFrameRcvd--;      m_cTEncTop.setFramesToBeEncoded(m_iFrameRcvd);    }    // call encoding function for one frame    <span style="color:#ff0000;">if ( m_isField ) m_cTEncTop.encode</span>( bEos, flush ? 0 : pcPicYuvOrg, flush ? 0 : &cPicYuvTrueOrg, snrCSC, m_cListPicYuvRec, outputAccessUnits, iNumEncoded, m_isTopFieldFirst );    <span style="color:#ff0000;">else             m_cTEncTop.encode(</span> bEos, flush ? 0 : pcPicYuvOrg, flush ? 0 : &cPicYuvTrueOrg, snrCSC, m_cListPicYuvRec, outputAccessUnits, iNumEncoded );    // write bistream to file if necessary    if ( iNumEncoded > 0 )    {      xWriteOutput(bitstreamFile, iNumEncoded, outputAccessUnits);      outputAccessUnits.clear();    }  }  m_cTEncTop.printSummary(m_isField);  // delete original YUV buffer  pcPicYuvOrg->destroy();  delete pcPicYuvOrg;  pcPicYuvOrg = NULL;  // delete used buffers in encoder class  m_cTEncTop.deletePicBuffer();  cPicYuvTrueOrg.destroy();  // delete buffers & classes  xDeleteBuffer();  xDestroyLib();  printRateSummary();  return;}

（3）这里面调用了函数m_cTEncTop.encode（这样说不知道对不对），这函数是类TEncTop中的类函数，在TEncTop.cpp中定义了。

Void <span style="color:#cc0000;">TEncTop::encode</span>( Bool flush, TComPicYuv* pcPicYuvOrg, TComPicYuv* pcPicYuvTrueOrg, const InputColourSpaceConversion snrCSC, TComList<TComPicYuv*>& rcListPicYuvRecOut, std::list<AccessUnit>& accessUnitsOut, Int& iNumEncoded ){  if (pcPicYuvOrg != NULL)  {    // get original YUV    TComPic* pcPicCurr = NULL;    xGetNewPicBuffer( pcPicCurr );    pcPicYuvOrg->copyToPic( pcPicCurr->getPicYuvOrg() );    pcPicYuvTrueOrg->copyToPic( pcPicCurr->getPicYuvTrueOrg() );    // compute image characteristics    if ( getUseAdaptiveQP() )    {      m_cPreanalyzer.xPreanalyze( dynamic_cast<TEncPic*>( pcPicCurr ) );    }  }  if ((m_iNumPicRcvd == 0) || (!flush && (m_iPOCLast != 0) && (m_iNumPicRcvd != m_iGOPSize) && (m_iGOPSize != 0)))  {    iNumEncoded = 0;    return;  }  if (<span style="color:#ff0000;"> m_RCEnableRateControl</span> )//在GOP层初始化  {    m_cRateCtrl.<span style="color:#ff0000;">initRCGOP</span>( m_iNumPicRcvd );//调用TENCRatectrl.cpp中的initRCGOP函数  }  // compress GOP  <span style="color:#ff0000;">m_cGOPEncoder.compressGOP</span>(m_iPOCLast, m_iNumPicRcvd, m_cListPic, rcListPicYuvRecOut, accessUnitsOut, false, false, snrCSC, m_printFrameMSE);  if ( m_RCEnableRateControl )  {   <span style="color:#ff0000;"> m_cRateCtrl.destroy</span>RCGOP();  }  iNumEncoded         = m_iNumPicRcvd;  m_iNumPicRcvd       = 0;  m_uiNumAllPicCoded += iNumEncoded;}

这个函数的定义中有调用后面TEncGOP类中的函数

<span style="color:#ff0000;">GOPEncoder.compressGOP</span>

和码率控制模块的初始化函数 m_cRateCtrl.initRCGOP( m_iNumPicRcvd ），这里是码率控制函数第一次（？？？不确定）被调用。。下面就有两条路线了，一条直接进入码率控制模块，一条继续进入GOP>>slice>>cu。。下面先进入GOP层。。。

（4）

<span style="color: rgb(255, 0, 0);">GOPEncoder.compressGOP</span>

GOPEncoder声明为类TencGOP的对象函数，所以GOPEncoder.compressGOP就是调用类TencGOP的类函数compressGOP函数。

Void <span style="color:#cc0000;">TEncGOP::compressGOP</span>( Int iPOCLast, Int iNumPicRcvd, TComList<TComPic*>& rcListPic,                           TComList<TComPicYuv*>& rcListPicYuvRecOut, std::list<AccessUnit>& accessUnitsInGOP,                           Bool isField, Bool isTff, const InputColourSpaceConversion snr_conversion, const Bool printFrameMSE ){  TComPic*        pcPic;  TComPicYuv*     pcPicYuvRecOut;  TComSlice*      pcSlice;  TComOutputBitstream  *pcBitstreamRedirect;  pcBitstreamRedirect = new TComOutputBitstream;  AccessUnit::iterator  itLocationToPushSliceHeaderNALU; // used to store location where NALU containing slice header is to be inserted  UInt                  uiOneBitstreamPerSliceLength = 0;  TEncSbac* pcSbacCoders = NULL;  TComOutputBitstream* pcSubstreamsOut = NULL;  xInitGOP( iPOCLast, iNumPicRcvd, rcListPic, rcListPicYuvRecOut, isField );  m_iNumPicCoded = 0;  SEIPictureTiming pictureTimingSEI;  Bool writeSOP = m_pcCfg->getSOPDescriptionSEIEnabled();

 

 while(nextCUAddr<uiRealEndAddress) // determine slice boundaries    {      pcSlice->setNextSlice       ( false );      pcSlice->setNextSliceSegment( false );      assert(pcPic->getNumAllocatedSlice() == startCUAddrSliceIdx);      m_pcSliceEncoder-><span style="color:#ff0000;">precompressSlice</span>( pcPic );      m_pcSliceEncoder-><span style="color:#cc0000;">compressSlice</span>   ( pcPic );

这两个调用的函数是定义在TEncSlice.cpp中的，转到定义处，进入TEncSlice.cpp
（5）

Void TEncSlice::<span style="color:#ff0000;">compressSlice</span>( TComPic*& rpcPic ){  UInt   uiStartCUAddr;  UInt   uiBoundingCUAddr;  rpcPic->getSlice(getSliceIdx())->setSliceSegmentBits(0);  TEncBinCABAC* pppcRDSbacCoder = NULL;  TComSlice* pcSlice            = rpcPic->getSlice(getSliceIdx());  xDetermineStartAndBoundingCUAddr ( uiStartCUAddr, uiBoundingCUAddr, rpcPic, false );  // initialize cost values  m_uiPicTotalBits  = 0;  m_dPicRdCost      = 0;  m_uiPicDist       = 0;  // set entropy coder

  // run CU encoder    m_pcCuEncoder-><span style="color:#ff0000;">compressCU</span>( pcCU );    // restore entropy coder to an initial stage

compressCU被调用，函数进入TEncCu.cpp中
（6）

Void <span style="color:#ff0000;">TEncCu::compressCU</span>( TComDataCU*& rpcCU ){  // initialize CU data  m_ppcBestCU[0]->initCU( rpcCU->getPic(), rpcCU->getAddr() );  m_ppcTempCU[0]->initCU( rpcCU->getPic(), rpcCU->getAddr() );  // analysis of CU  DEBUG_STRING_NEW(sDebug)  xCompressCU( m_ppcBestCU[0], m_ppcTempCU[0], 0 DEBUG_STRING_PASS_INTO(sDebug) );  DEBUG_STRING_OUTPUT(std::cout, sDebug)

这就走到最底层了吧？我是这么想的。。哈哈。。。还有就是在GOP<<slice<<cu每层都有调用RDcost   ratecontrol类中的函数。。也就是这些控制在过程都有用到。现在还不知道怎么弄得，接下来就是分析这些了，那里调用了，为什么调用，为什么在哪里调用？？对应的原理是什么，把代码翻译成理论。。。。。。