HEVC代码学习16：运动矢量MV的数据结构

今天学习MV的数据结构，进一步理解MV的存储、处理等各种操作。

TComMv

先来看基本的MV类TComMv。可以看到MV是以水平分量m_iHor和垂直分量m_iVer的形式存储的，类中包含了设置、获取、加减、比较等函数。

class TComMv{private:  //MV水平和垂直分量  Short m_iHor;     ///< horizontal component of motion vector  Short m_iVer;     ///< vertical component of motion vectorpublic:  // ------------------------------------------------------------------------------------------------------------------  // constructors  // ------------------------------------------------------------------------------------------------------------------  TComMv() :  m_iHor(0),  m_iVer(0)  {  }  TComMv( Short iHor, Short iVer ) :  m_iHor(iHor),  m_iVer(iVer)  {  }  // ------------------------------------------------------------------------------------------------------------------  // set  // ------------------------------------------------------------------------------------------------------------------  Void  set       ( Short iHor, Short iVer)     { m_iHor = iHor;  m_iVer = iVer;            }  Void  setHor    ( Short i )                   { m_iHor = i;                               }  Void  setVer    ( Short i )                   { m_iVer = i;                               }  Void  setZero   ()                            { m_iHor = m_iVer = 0;        }  // ------------------------------------------------------------------------------------------------------------------  // get  // ------------------------------------------------------------------------------------------------------------------  Int   getHor    () const { return m_iHor;          }  Int   getVer    () const { return m_iVer;          }  Int   getAbsHor () const { return abs( m_iHor );   }  Int   getAbsVer () const { return abs( m_iVer );   }  // ------------------------------------------------------------------------------------------------------------------  // operations  // ------------------------------------------------------------------------------------------------------------------  const TComMv& operator += (const TComMv& rcMv)  {    m_iHor += rcMv.m_iHor;    m_iVer += rcMv.m_iVer;    return  *this;  }  const TComMv& operator-= (const TComMv& rcMv)  {    m_iHor -= rcMv.m_iHor;    m_iVer -= rcMv.m_iVer;    return  *this;  }  const TComMv& operator>>= (const Int i)  {    m_iHor >>= i;    m_iVer >>= i;    return  *this;  }  const TComMv& operator<<= (const Int i)  {    m_iHor <<= i;    m_iVer <<= i;    return  *this;  }  const TComMv operator - ( const TComMv& rcMv ) const  {    return TComMv( m_iHor - rcMv.m_iHor, m_iVer - rcMv.m_iVer );  }  const TComMv operator + ( const TComMv& rcMv ) const  {    return TComMv( m_iHor + rcMv.m_iHor, m_iVer + rcMv.m_iVer );  }  Bool operator== ( const TComMv& rcMv ) const  {    return (m_iHor==rcMv.m_iHor && m_iVer==rcMv.m_iVer);  }  Bool operator!= ( const TComMv& rcMv ) const  {    return (m_iHor!=rcMv.m_iHor || m_iVer!=rcMv.m_iVer);  }  const TComMv scaleMv( Int iScale ) const  {    Int mvx = Clip3( -32768, 32767, (iScale * getHor() + 127 + (iScale * getHor() < 0)) >> 8 );    Int mvy = Clip3( -32768, 32767, (iScale * getVer() + 127 + (iScale * getVer() < 0)) >> 8 );    return TComMv( mvx, mvy );  }};// END CLASS DEFINITION TComMV//! \}

AMVPInfo

用于AMVP信息，包括运动矢量候选列表及数量。

//AMVP参数信息/// parameters for AMVPtypedef struct _AMVPInfo{  TComMv m_acMvCand[ AMVP_MAX_NUM_CANDS_MEM ];  ///< array of motion vector predictor candidates    运动矢量候选列表  Int    iN;                                ///< number of motion vector predictor candidates       运动矢量候选数量} AMVPInfo;

TComMvField

TComMvField是带索引的MV信息，里面存储了基本MV加索引，包含了对MV和索引的操作函数。
在TComDataCU中定义了getMvField，用于获取该CU的带索引的MV信息。

/// class for motion vector with reference indexclass TComMvField{private:  TComMv    m_acMv;     //MV信息  Int       m_iRefIdx;  //索引public:  TComMvField() : m_iRefIdx( NOT_VALID ) {}  Void setMvField( TComMv const & cMv, Int iRefIdx )    //设置MV和索引  {    m_acMv    = cMv;    m_iRefIdx = iRefIdx;  }  Void setRefIdx( Int refIdx ) { m_iRefIdx = refIdx; }      //设置索引  TComMv const & getMv() const { return  m_acMv; }      //获取MV  TComMv       & getMv()       { return  m_acMv; }  Int getRefIdx() const { return  m_iRefIdx;       }    //获取索引  Int getHor   () const { return  m_acMv.getHor(); }    //获取MV水平分量  Int getVer   () const { return  m_acMv.getVer(); }    //获取MV垂直分量};

TComCUMvField

TComCUMvField是CU的MV信息，带有更多的信息。
在TComDataCU中定义了m_acCUMvField[NUM_REF_PIC_LIST_01]，用于存储CU的MV信息。还定义了 getCUMvField函数，用于获取m_acCUMvField。

/// class for motion information in one CU//CU的MV信息class TComCUMvField{private:  TComMv*   m_pcMv;     //MV  TComMv*   m_pcMvd;    //MVD  Char*     m_piRefIdx;     //索引  UInt      m_uiNumPartition;   //分块  AMVPInfo  m_cAMVPInfo;    //AMVP信息  template <typename T>  Void setAll( T *p, T const & val, PartSize eCUMode, Int iPartAddr, UInt uiDepth, Int iPartIdx );public:  TComCUMvField() : m_pcMv(NULL), m_pcMvd(NULL), m_piRefIdx(NULL), m_uiNumPartition(0) {}  ~TComCUMvField() {}  // ------------------------------------------------------------------------------------------------------------------  // create / destroy  // ------------------------------------------------------------------------------------------------------------------  Void    create( UInt uiNumPartition );  Void    destroy();  // ------------------------------------------------------------------------------------------------------------------  // clear / copy  // ------------------------------------------------------------------------------------------------------------------  Void    clearMvField();       //清理MV  //复制  Void    copyFrom( TComCUMvField const * pcCUMvFieldSrc, Int iNumPartSrc, Int iPartAddrDst );  Void    copyTo  ( TComCUMvField* pcCUMvFieldDst, Int iPartAddrDst ) const;  Void    copyTo  ( TComCUMvField* pcCUMvFieldDst, Int iPartAddrDst, UInt uiOffset, UInt uiNumPart ) const;  // ------------------------------------------------------------------------------------------------------------------  // get  // ------------------------------------------------------------------------------------------------------------------  //获取  TComMv const & getMv    ( Int iIdx ) const { return  m_pcMv    [iIdx]; }  TComMv const & getMvd   ( Int iIdx ) const { return  m_pcMvd   [iIdx]; }  Int            getRefIdx( Int iIdx ) const { return  m_piRefIdx[iIdx]; }  AMVPInfo* getAMVPInfo () { return &m_cAMVPInfo; }  // ------------------------------------------------------------------------------------------------------------------  // set  // ------------------------------------------------------------------------------------------------------------------  //设置  Void    setAllMv     ( TComMv const & rcMv,         PartSize eCUMode, Int iPartAddr, UInt uiDepth, Int iPartIdx=0 );  Void    setAllMvd    ( TComMv const & rcMvd,        PartSize eCUMode, Int iPartAddr, UInt uiDepth, Int iPartIdx=0 );  Void    setAllRefIdx ( Int iRefIdx,                 PartSize eMbMode, Int iPartAddr, UInt uiDepth, Int iPartIdx=0 );  Void    setAllMvField( TComMvField const & mvField, PartSize eMbMode, Int iPartAddr, UInt uiDepth, Int iPartIdx=0 );  Void setNumPartition( Int iNumPart )  {    m_uiNumPartition = iNumPart;  }  Void linkToWithOffset( TComCUMvField const * src, Int offset )  {    m_pcMv     = src->m_pcMv     + offset;    m_pcMvd    = src->m_pcMvd    + offset;    m_piRefIdx = src->m_piRefIdx + offset;  }  //压缩  Void compress(Char* pePredMode, Int scale);};