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📄 loopfilter.c

📁 H.264基于baseline解码器的C++实现源码
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/*!
 *************************************************************************************
 * \file loopFilter.c
 *
 * \brief
 *    Filter to reduce blocking artifacts on a macroblock level.
 *    The filter strength is QP dependent.
 *
 * \author
 *    Contributors:
 *    - Peter List       Peter.List@t-systems.de:  Original code                                 (13-Aug-2001)
 *    - Jani Lainema     Jani.Lainema@nokia.com:   Some bug fixing, removal of recursiveness     (16-Aug-2001)
 *    - Peter List       Peter.List@t-systems.de:  inplace filtering and various simplifications (10-Jan-2002)
 *    - Anthony Joch     anthony@ubvideo.com:      Simplified switching between filters and
 *                                                 non-recursive default filter.                 (08-Jul-2002)
 *    - Cristina Gomila  cristina.gomila@thomson.net: Simplification of the chroma deblocking
 *                                                    from JVT-E089                              (21-Nov-2002)
 *    - Alexis Michael Tourapis atour@dolby.com:   Speed/Architecture improvements               (08-Feb-2007)
 *************************************************************************************
 */

#include "global.h"
#include "image.h"
#include "mb_access.h"
#include "loopfilter.h"

byte mixedModeEdgeFlag, fieldModeFilteringFlag;

static int64  **list0_refPicIdArr, **list1_refPicIdArr;
static short  ***list0_mv, ***list1_mv;
static char   **list0_refIdxArr, **list1_refIdxArr;
static Macroblock *MbP;
static imgpel   *SrcPtrP, *SrcPtrQ;

/*********************************************************************************************************/

// NOTE: In principle, the alpha and beta tables are calculated with the formulas below
//       Alpha( qp ) = 0.8 * (2^(qp/6)  -  1)
//       Beta ( qp ) = 0.5 * qp  -  7

// The tables actually used have been "hand optimized" though (by Anthony Joch). So, the
// table values might be a little different to formula-generated values. Also, the first
// few values of both tables is set to zero to force the filter off at low qp抯

static const byte ALPHA_TABLE[52]  = {0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,4,4,5,6,  7,8,9,10,12,13,15,17,  20,22,25,28,32,36,40,45,  50,56,63,71,80,90,101,113,  127,144,162,182,203,226,255,255} ;
static const byte  BETA_TABLE[52]  = {0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,2,2,2,3,  3,3,3, 4, 4, 4, 6, 6,   7, 7, 8, 8, 9, 9,10,10,  11,11,12,12,13,13, 14, 14,   15, 15, 16, 16, 17, 17, 18, 18} ;
static const byte CLIP_TAB[52][5]  =
{
  { 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},
  { 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},{ 0, 0, 0, 0, 0},
  { 0, 0, 0, 0, 0},{ 0, 0, 0, 1, 1},{ 0, 0, 0, 1, 1},{ 0, 0, 0, 1, 1},{ 0, 0, 0, 1, 1},{ 0, 0, 1, 1, 1},{ 0, 0, 1, 1, 1},{ 0, 1, 1, 1, 1},
  { 0, 1, 1, 1, 1},{ 0, 1, 1, 1, 1},{ 0, 1, 1, 1, 1},{ 0, 1, 1, 2, 2},{ 0, 1, 1, 2, 2},{ 0, 1, 1, 2, 2},{ 0, 1, 1, 2, 2},{ 0, 1, 2, 3, 3},
  { 0, 1, 2, 3, 3},{ 0, 2, 2, 3, 3},{ 0, 2, 2, 4, 4},{ 0, 2, 3, 4, 4},{ 0, 2, 3, 4, 4},{ 0, 3, 3, 5, 5},{ 0, 3, 4, 6, 6},{ 0, 3, 4, 6, 6},
  { 0, 4, 5, 7, 7},{ 0, 4, 5, 8, 8},{ 0, 4, 6, 9, 9},{ 0, 5, 7,10,10},{ 0, 6, 8,11,11},{ 0, 6, 8,13,13},{ 0, 7,10,14,14},{ 0, 8,11,16,16},
  { 0, 9,12,18,18},{ 0,10,13,20,20},{ 0,11,15,23,23},{ 0,13,17,25,25}
} ;

static const char chroma_edge[2][4][4] = //[dir][edge][yuv_format]
{ { {-4, 0, 0, 0},
    {-4,-4,-4, 4},
    {-4, 4, 4, 8},
    {-4,-4,-4, 12}},

  { {-4, 0,  0,  0},
    {-4,-4,  4,  4},
    {-4, 4,  8,  8},
    {-4,-4, 12, 12}}};

static const int pelnum_cr[2][4] =  {{0,8,16,16}, {0,8, 8,16}};  //[dir:0=vert, 1=hor.][yuv_format]

void (*GetStrength)    (byte Strength[16],ImageParameters *img, Macroblock *MbQ, int dir,int edge, int mvlimit,StorablePicture *p);
void GetStrengthNormal (byte Strength[16],ImageParameters *img, Macroblock *MbQ, int dir,int edge, int mvlimit,StorablePicture *p);
void GetStrengthMBAff  (byte Strength[16],ImageParameters *img, Macroblock *MbQ, int dir,int edge, int mvlimit,StorablePicture *p);
void (*EdgeLoopLuma)   (ColorPlane pl, imgpel** Img, byte Strength[16],ImageParameters *img, Macroblock *MbQ, int dir, int edge, StorablePicture *p);
void EdgeLoopLumaNormal(ColorPlane pl, imgpel** Img, byte Strength[16],ImageParameters *img, Macroblock *MbQ, int dir, int edge, StorablePicture *p);
void EdgeLoopLumaMBAff (ColorPlane pl, imgpel** Img, byte Strength[16],ImageParameters *img, Macroblock *MbQ, int dir, int edge, StorablePicture *p);
void (*EdgeLoopChroma)(imgpel** Img, byte Strength[16],ImageParameters *img, Macroblock *MbQ, int dir, int edge, int uv, StorablePicture *p);
void EdgeLoopChromaNormal(imgpel** Img, byte Strength[16],ImageParameters *img, Macroblock *MbQ, int dir, int edge, int uv, StorablePicture *p);
void EdgeLoopChromaMBAff(imgpel** Img, byte Strength[16],ImageParameters *img, Macroblock *MbQ, int dir, int edge, int uv, StorablePicture *p);
void DeblockMb(ImageParameters *img, StorablePicture *p, int MbQAddr);
int compute_deblock_strength(char **list0_refIdxArr, char **list1_refIdxArr, int64 **list0_refPicIdArr, int64 **list1_refPicIdArr, 
                             short  ***list0_mv, short  ***list1_mv, int blk_y, int blk_x, int blk_y2, int blk_x2, int mvlimit);

/*!
 *****************************************************************************************
 * \brief
 *    Filter all macroblocks in order of increasing macroblock address.
 *****************************************************************************************
 */
void DeblockPicture(ImageParameters *img, StorablePicture *p)
{
  unsigned i;

  if (p->MbaffFrameFlag == 1) 
  {
    GetStrength    = GetStrengthMBAff;
    EdgeLoopLuma   = EdgeLoopLumaMBAff;
    EdgeLoopChroma = EdgeLoopChromaMBAff;
  }
  else
  {
    GetStrength    = GetStrengthNormal;
    EdgeLoopLuma   = EdgeLoopLumaNormal;
    EdgeLoopChroma = EdgeLoopChromaNormal;
  }

  for (i = 0; i < p->PicSizeInMbs; i++)
  {
    DeblockMb( img, p, i ) ;
  }
}


/*!
 *****************************************************************************************
 * \brief
 *    Deblocking filter for one macroblock.
 *****************************************************************************************
 */

void DeblockMb(ImageParameters *img, StorablePicture *p, int MbQAddr)
{
  int           EdgeCondition;
  int           dir, edge;
  byte          Strength[16];
  int           mb_x, mb_y;
  
  int           filterNon8x8LumaEdgesFlag[4] = {1,1,1,1};
  int           filterLeftMbEdgeFlag;
  int           filterTopMbEdgeFlag;
  int           fieldModeMbFlag;
  int           mvlimit = 4;
  int           i, StrengthSum;
  Macroblock    *MbQ = &(img->mb_data[MbQAddr]) ; // current Mb
  imgpel **imgY   = p->imgY;
  imgpel ***imgUV = p->imgUV;
  
  int           edge_cr;

  // return, if filter is disabled
  if (MbQ->DFDisableIdc==1) 
  {
    img->DeblockCall = 0;
    return;
  }

  img->DeblockCall = 1;
  get_mb_pos (MbQAddr, img->mb_size[IS_LUMA], &mb_x, &mb_y);
  
  filterLeftMbEdgeFlag = (mb_x != 0);
  filterTopMbEdgeFlag  = (mb_y != 0);
  
  if (MbQ->mb_type == I8MB)
    assert(MbQ->luma_transform_size_8x8_flag);
  
  filterNon8x8LumaEdgesFlag[1] =
  filterNon8x8LumaEdgesFlag[3] = !(MbQ->luma_transform_size_8x8_flag);
  
  if (p->MbaffFrameFlag && mb_y == MB_BLOCK_SIZE && MbQ->mb_field)
    filterTopMbEdgeFlag = 0;
  
  fieldModeMbFlag = (p->structure!=FRAME) || (p->MbaffFrameFlag && MbQ->mb_field);
  if (fieldModeMbFlag)
    mvlimit = 2;
  
  if (MbQ->DFDisableIdc==2)
  {
    // don't filter at slice boundaries
    filterLeftMbEdgeFlag = MbQ->mbAvailA;
    // if this the bottom of a frame macroblock pair then always filter the top edge
    filterTopMbEdgeFlag  = (p->MbaffFrameFlag && !MbQ->mb_field && (MbQAddr & 0x01)) ? 1 : MbQ->mbAvailB;
  }
  img->current_mb_nr = MbQAddr;
  CheckAvailabilityOfNeighbors(MbQ);

  for( dir = 0 ; dir < 2 ; dir++ )                                                      // filter first vertical edges, followed by horizontal 
  {
    EdgeCondition = (dir && filterTopMbEdgeFlag) || (!dir && filterLeftMbEdgeFlag); // can not filter beyond picture boundaries
    for( edge=0; edge<4 ; edge++ )                                            // first 4 vertical strips of 16 pel
    {                                                                               // then  4 horizontal
      if( edge || EdgeCondition )
      {
        edge_cr = chroma_edge[dir][edge][p->chroma_format_idc];

        GetStrength(Strength, img, MbQ, dir, edge << 2, mvlimit, p); // Strength for 4 blks in 1 stripe
        StrengthSum = Strength[0];
        for (i = 1; i < MB_BLOCK_SIZE && StrengthSum == 0 ; i++)
        {
          StrengthSum += (int) Strength[i];
        }
        
        if( StrengthSum )                      // only if one of the 16 Strength bytes is != 0
        {
          if (filterNon8x8LumaEdgesFlag[edge])
          {
            EdgeLoopLuma( PLANE_Y, imgY, Strength, img, MbQ, dir, edge << 2, p) ;
            if( active_sps->chroma_format_idc==YUV444 && !IS_INDEPENDENT(img) )
            {
              EdgeLoopLuma(PLANE_U, imgUV[0], Strength, img, MbQ, dir, edge << 2, p);
              EdgeLoopLuma(PLANE_V, imgUV[1], Strength, img, MbQ, dir, edge << 2, p);
            }
          }
          if (active_sps->chroma_format_idc==YUV420 || active_sps->chroma_format_idc==YUV422)
          {
            if( (imgUV != NULL) && (edge_cr >= 0))
            {
              EdgeLoopChroma( imgUV[0], Strength, img, MbQ, dir, edge_cr, 0, p);
              EdgeLoopChroma( imgUV[1], Strength, img, MbQ, dir, edge_cr, 1, p);
            }
          }
        }
        
        if (dir && !edge && !MbQ->mb_field && mixedModeEdgeFlag) 
        {
          // this is the extra horizontal edge between a frame macroblock pair and a field above it
          img->DeblockCall = 2;
          GetStrength(Strength, img, MbQ, dir, MB_BLOCK_SIZE, mvlimit, p); // Strength for 4 blks in 1 stripe
          //if( *((int*)Strength) )                      // only if one of the 4 Strength bytes is != 0
          {
            if (filterNon8x8LumaEdgesFlag[edge])
            {
              EdgeLoopLuma(PLANE_Y, imgY, Strength, img, MbQ, dir, MB_BLOCK_SIZE, p) ;
              if( active_sps->chroma_format_idc==YUV444 && !IS_INDEPENDENT(img) )
              {
                EdgeLoopLuma(PLANE_U, imgUV[0], Strength, img, MbQ, dir, MB_BLOCK_SIZE, p) ;
                EdgeLoopLuma(PLANE_V, imgUV[1], Strength, img, MbQ, dir, MB_BLOCK_SIZE, p) ;
              }
            }
            if (active_sps->chroma_format_idc==YUV420 || active_sps->chroma_format_idc==YUV422) 
            {
              if( (imgUV != NULL) && (edge_cr >= 0))
              {
                EdgeLoopChroma( imgUV[0], Strength, img, MbQ, dir, MB_BLOCK_SIZE, 0, p) ;
                EdgeLoopChroma( imgUV[1], Strength, img, MbQ, dir, MB_BLOCK_SIZE, 1, p) ;
              }
            }
          }
          img->DeblockCall = 1;
        }
      }
    }//end edge
  }//end loop dir
  
  img->DeblockCall = 0;
}

  /*!
 *********************************************************************************************
 * \brief
 *    returns a buffer of 16 Strength values for one stripe in a mb (for different Frame or Field types)
 *********************************************************************************************
 */

#define ANY_INTRA (MbP->mb_type==I4MB||MbP->mb_type==I8MB||MbP->mb_type==I16MB||MbP->mb_type==IPCM||MbQ->mb_type==I4MB||MbQ->mb_type==I8MB||MbQ->mb_type==I16MB||MbQ->mb_type==IPCM)

void GetStrengthNormal(byte Strength[MB_BLOCK_SIZE], ImageParameters *img, Macroblock *MbQ, int dir, int edge, int mvlimit, StorablePicture *p)
{
  static int64    ref_p0,ref_p1,ref_q0,ref_q1;
  static int      blkP, blkQ, idx;
  static int      blk_x, blk_x2, blk_y, blk_y2 ;
  static int      xQ, yQ;
  static int      mb_x, mb_y;
  static PixelPos pixP, pixMB;
  static byte     StrValue;

  if ((p->slice_type==SP_SLICE)||(p->slice_type==SI_SLICE) )
  { 
    // Set strength to either 3 or 4 regardless of pixel position
    StrValue = (edge == 0 && (((p->structure==FRAME)) || ((p->structure != FRAME) && !dir))) ? 4 : 3;
    memset(&Strength[0], (byte) StrValue, MB_BLOCK_SIZE * sizeof(byte));
  }
  else
  {    
    xQ = dir ? 0 : edge - 1;
    yQ = dir ? (edge < 16 ? edge - 1: 0) : 0;

    getNeighbour(MbQ, xQ, yQ, img->mb_size[IS_LUMA], &pixMB);
    pixP = pixMB;
    MbP = &(img->mb_data[pixP.mb_addr]);

    if (!ANY_INTRA)
    {
      PicMotionParams *motion = &p->motion;
      list0_refPicIdArr = motion->ref_pic_id[LIST_0];
      list1_refPicIdArr = motion->ref_pic_id[LIST_1];
      list0_mv = motion->mv[LIST_0];
      list1_mv = motion->mv[LIST_1];
      list0_refIdxArr = motion->ref_idx[LIST_0];
      list1_refIdxArr = motion->ref_idx[LIST_1];

      get_mb_block_pos (MbQ->mbAddrX, &mb_x, &mb_y);
      mb_x <<= 2;
      mb_y <<= 2;

      yQ += dir;
      xQ += (1 - dir);

      for( idx = 0 ; idx < MB_BLOCK_SIZE ; idx += BLOCK_SIZE )
      {
        if (dir)
        {
          xQ = idx;
          pixP.x = pixMB.x + idx;
          pixP.pos_x = pixMB.pos_x + idx;
        }
        else
        {
          yQ = idx;
          pixP.y = pixMB.y + idx;
          pixP.pos_y = pixMB.pos_y + idx;
        }

        blkQ = (yQ & 0xFFFC) + (xQ >> 2);
        blkP = (pixP.y & 0xFFFC) + (pixP.x >> 2);

        if( ((MbQ->cbp_blk[0] & ((int64)1 << blkQ )) != 0) || ((MbP->cbp_blk[0] & ((int64)1 << blkP)) != 0) )
          StrValue = 2;
        else
        {
          // if no coefs, but vector difference >= 1 set Strength=1
          // if this is a mixed mode edge then one set of reference pictures will be frame and the
          // other will be field          
          blk_y  = mb_y + (blkQ >> 2);
          blk_x  = mb_x + (blkQ  & 3);
          blk_y2 = pixP.pos_y >> 2;
          blk_x2 = pixP.pos_x >> 2;

          ref_p0 = list0_refIdxArr[blk_y ][blk_x ] < 0 ? INT64_MIN : list0_refPicIdArr[blk_y ][blk_x ];
          ref_q0 = list0_refIdxArr[blk_y2][blk_x2] < 0 ? INT64_MIN : list0_refPicIdArr[blk_y2][blk_x2];
          ref_p1 = list1_refIdxArr[blk_y ][blk_x ] < 0 ? INT64_MIN : list1_refPicIdArr[blk_y ][blk_x ];
          ref_q1 = list1_refIdxArr[blk_y2][blk_x2] < 0 ? INT64_MIN : list1_refPicIdArr[blk_y2][blk_x2];
          if ( ((ref_p0==ref_q0) && (ref_p1==ref_q1)) || ((ref_p0==ref_q1) && (ref_p1==ref_q0)))
          {
            // L0 and L1 reference pictures of p0 are different; q0 as well
            if (ref_p0 != ref_p1)
            {
              // compare MV for the same reference picture
              if (ref_p0 == ref_q0)
              {
                if (ref_p0 == INT64_MIN)
                {
                  StrValue =  (byte) (
                    (iabs( list1_mv[blk_y][blk_x][0] - list1_mv[blk_y2][blk_x2][0]) >= 4) |
                    (iabs( list1_mv[blk_y][blk_x][1] - list1_mv[blk_y2][blk_x2][1]) >= mvlimit));

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