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/*! 
 ************************************************************************************* 
 * \file loopFilter.c 
 * 
 * \brief 
 *    Filter to reduce blocking artifacts on a macroblock level. 
 *    The filter strengh 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 recusiveness      (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) 
 ************************************************************************************* 
 */ 
#include  
#include  
#include "global.h" 
#include "image.h" 
#include "mb_access.h" 
 
extern const byte QP_SCALE_CR[52] ; 
 
/*********************************************************************************************************/ 
 
// NOTE: to change the tables below for instance when the QP doubling is changed from 6 to 8 values  
//       send an e-mail to Peter.List@t-systems.com to get a little programm that calculates them automatically  
 
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} ; 
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} ; 
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} 
} ; 
 
 
void GetStrength(byte Strength[4],struct img_par *img,Macroblock* MbP,Macroblock* MbQ,int dir,int edge,int mb_y,int mb_x, int mvlimit); 
void EdgeLoop(byte* SrcPtr,byte Strength[4], int QP, int AlphaC0Offset, int BetaOffset, int dir,int width,int yuv); 
void DeblockMb(ImageParameters *img, byte **imgY, byte ***imgUV, int mb_y, int mb_x) ; 
 
/*! 
 ***************************************************************************************** 
 * \brief 
 *    Filter all macroblocks in order of increasing macroblock address. 
 ***************************************************************************************** 
 */ 
void DeblockFrame(ImageParameters *img, byte **imgY, byte ***imgUV) 
{ 
  unsigned i; 
  int mb_x, mb_y ; 
 
  for (i=0; iPicSizeInMbs; i++) 
  { 
    get_mb_block_pos(i, &mb_x, &mb_y); 
    DeblockMb( img, imgY, imgUV, mb_y, mb_x ) ; 
  } 
}  
 
 
/*! 
 ***************************************************************************************** 
 * \brief 
 *    Deblocking filter for one macroblock. 
 ***************************************************************************************** 
 */ 
 
void DeblockMb(ImageParameters *img, byte **imgY, byte ***imgUV, int mb_y, int mb_x) 
{ 
  int           EdgeCondition; 
  int           dir,edge,QP; 
  byte          Strength[4], *SrcY, *SrcU, *SrcV ; 
  Macroblock    *MbP, *MbQ ;  
  int           sizey; 
  int           QPC; 
 
  int           filterLeftMbEdgeFlag  = (mb_x != 0); 
  int           filterTopMbEdgeFlag   = (mb_y != 0); 
  int           fieldModeMbFlag; 
  int           mvlimit=4; 
   
  SrcY = imgY    [mb_y<<4] + (mb_x<<4) ;                                                      // pointers to source 
  SrcU = imgUV[0][mb_y<<3] + (mb_x<<3) ; 
  SrcV = imgUV[1][mb_y<<3] + (mb_x<<3) ; 
 
  MbQ  = &img->mb_data[mb_y*img->PicWidthInMbs + mb_x] ;                                                 // current Mb 
 
  fieldModeMbFlag       = img->field_pic_flag || (img->MbaffFrameFlag && MbQ->mb_field); 
  if (fieldModeMbFlag) 
    mvlimit = 2; 
 
  // return, if filter is disabled 
  if (MbQ->LFDisableIdc==1) return; 
 
  if (MbQ->LFDisableIdc==2) 
  { 
    // don't filter at slice boundaries 
    filterLeftMbEdgeFlag = MbQ->mbAvailA; 
    filterTopMbEdgeFlag  = MbQ->mbAvailB;; 
  } 
 
  for( dir=0 ; dir<2 ; dir++ )                                             // vertical edges, than horicontal edges 
  { 
    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 horicontal 
      if( edge || EdgeCondition ) 
      { 
        sizey = mb_y%2 ? 1:2*img->width/MB_BLOCK_SIZE-1; 
        MbP = (edge)? MbQ : ((dir)? (MbQ -(img->width>>4))  : (MbQ-1) ) ;       // MbP = Mb of the remote 4x4 block 
 
        // As in Draft, if MB is IPCM, MB->qp should be 0 or corresponding value of 0 for chroma 
        // This is set in decode_ipcm_mb() and here affect the values of QP and QPC (QP_SCALE_CR[]) 
 
        QP  = ( MbP->qp + MbQ->qp + 1) >> 1 ;                   // Average QP of the two blocks 
        GetStrength(Strength,img,MbP,MbQ,dir,edge,mb_y<<2,mb_x<<2, mvlimit); // Strength for 4 blks in 1 stripe 
        if( *((int*)Strength) )                      // only if one of the 4 Strength bytes is != 0 
        { 
          EdgeLoop( SrcY + (edge<<2)* ((dir)? img->width:1 ), Strength, QP, MbQ->LFAlphaC0Offset, MbQ->LFBetaOffset, dir, img->width, 0) ;  
          if( (imgUV != NULL) && !(edge & 1) ) 
          { 
            int qp_uv_p, qp_uv_q; 
            qp_uv_p = MbP->qp + active_pps->chroma_qp_index_offset; 
            qp_uv_p = Clip3(0,51,qp_uv_p); 
            qp_uv_q = MbQ->qp + active_pps->chroma_qp_index_offset; 
            qp_uv_q = Clip3(0,51,qp_uv_q); 
            QPC  = (QP_SCALE_CR[qp_uv_p] + QP_SCALE_CR[qp_uv_q] + 1) >> 1; 
            EdgeLoop( SrcU +  (edge<<1) * ((dir)? img->width_cr:1 ), Strength, QPC, MbQ->LFAlphaC0Offset, MbQ->LFBetaOffset, dir, img->width_cr, 1 ) ;  
            EdgeLoop( SrcV +  (edge<<1) * ((dir)? img->width_cr:1 ), Strength, QPC, MbQ->LFAlphaC0Offset, MbQ->LFBetaOffset, dir, img->width_cr, 1 ) ;  
          } 
        } 
      } 
    }//end edge 
  }//end loop dir 
} 
 
  /*! 
 ********************************************************************************************* 
 * \brief 
 *    returns a buffer of 4 Strength values for one stripe in a mb (for different Frame types) 
 ********************************************************************************************* 
 */ 
 
int  ININT_STRENGTH[4] = {0x04040404, 0x03030303, 0x03030303, 0x03030303} ;  
byte BLK_NUM[2][4][4]  = {{{0,4,8,12},{1,5,9,13},{2,6,10,14},{3,7,11,15}},{{0,1,2,3},{4,5,6,7},{8,9,10,11},{12,13,14,15}}} ; 
byte BLK_4_TO_8[16]    = {0,0,1,1,0,0,1,1,2,2,3,3,2,2,3,3} ; 
 
void GetStrength(byte Strength[4],struct img_par *img,Macroblock* MbP,Macroblock* MbQ,int dir,int edge,int block_y,int block_x, int mvlimit) 
{ 
  int    blkP, blkQ, idx ; 
  int    blk_x, blk_x2, blk_y, blk_y2 ; 
  int    ***list0_mv = dec_picture->mv[LIST_0]; 
  int    ***list1_mv = dec_picture->mv[LIST_1]; 
  int    **list0_refIdxArr = dec_picture->ref_idx[LIST_0]; 
  int    **list1_refIdxArr = dec_picture->ref_idx[LIST_1]; 
  int64  **list0_refPicIdArr = dec_picture->ref_pic_id[LIST_0]; 
  int64  **list1_refPicIdArr = dec_picture->ref_pic_id[LIST_1]; 
 
  if ((img->structure==FRAME) || !dir) 
    *((int*)Strength) = ININT_STRENGTH[edge] ;                     // Start with Strength=3. or Strength=4 for Mb-edge 
  else 
    *((int*)Strength) = ININT_STRENGTH[3] ;                        //  Strength=3. for fields 
 
 
  for( idx=0 ; idx<4 ; idx++ ) 
  {                                                                                       // if not intra or SP-frame 
    blkQ = BLK_NUM[dir][ edge       ][idx] ;                 // if one of the 4x4 blocks has coefs.    set Strength=2 
    blkP = BLK_NUM[dir][(edge-1) & 3][idx] ;  
     
    if(  !(MbP->mb_type==I4MB || MbP->mb_type==I16MB || MbP->mb_type==IPCM) 
          && !(MbQ->mb_type==I4MB || MbQ->mb_type==I16MB || MbQ->mb_type==IPCM) ) 
    { 
      if( ((MbQ->cbp_blk &  (1 << blkQ )) != 0) || ((MbP->cbp_blk &  (1 << blkP)) != 0) ) 
        Strength[idx] = 2 ; 
      else 
      {                                                     // if no coefs, but vector difference >= 1 set Strength=1  
        blk_y  = block_y + (blkQ >> 2) ;   blk_y2 = blk_y -  dir ; 
        blk_x  = block_x + (blkQ  & 3) ;   blk_x2 = blk_x - !dir ; 
        if( (img->type == B_SLICE) ) 
        { 
          int64 ref_p0,ref_p1,ref_q0,ref_q1;       
          ref_p0 = list0_refIdxArr[blk_x][blk_y]<0 ? -1 : list0_refPicIdArr[blk_x][blk_y]; 
          ref_q0 = list0_refIdxArr[blk_x2][blk_y2]<0 ? -1 : list0_refPicIdArr[blk_x2][blk_y2]; 
          ref_p1 = list1_refIdxArr[blk_x][blk_y]<0 ? -1 : list1_refPicIdArr[blk_x][blk_y]; 
          ref_q1 = list1_refIdxArr[blk_x2][blk_y2]<0 ? -1 : list1_refPicIdArr[blk_x2][blk_y2]; 
          if ( ((ref_p0==ref_q0) && (ref_p1==ref_q1)) || 
            ((ref_p0==ref_q1) && (ref_p1==ref_q0)))  
          { 
            Strength[idx]=0; 
            // 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)  
              { 
                Strength[idx] =  (abs( list0_mv[blk_x][blk_y][0] - list0_mv[blk_x2][blk_y2][0]) >= 4) | 
                  (abs( list0_mv[blk_x][blk_y][1] - list0_mv[blk_x2][blk_y2][1]) >= mvlimit) | 
                  (abs( list1_mv[blk_x][blk_y][0] - list1_mv[blk_x2][blk_y2][0]) >= 4) | 
                  (abs( list1_mv[blk_x][blk_y][1] - list1_mv[blk_x2][blk_y2][1]) >= mvlimit); 
              } 
              else  
              { 
                Strength[idx] =  (abs( list0_mv[blk_x][blk_y][0] - list1_mv[blk_x2][blk_y2][0]) >= 4) | 
                  (abs( list0_mv[blk_x][blk_y][1] - list1_mv[blk_x2][blk_y2][1]) >= mvlimit) | 
                  (abs( list1_mv[blk_x][blk_y][0] - list0_mv[blk_x2][blk_y2][0]) >= 4) | 
                  (abs( list1_mv[blk_x][blk_y][1] - list0_mv[blk_x2][blk_y2][1]) >= mvlimit); 
              }  
            } 
            else  
            { // L0 and L1 reference pictures of p0 are the same; q0 as well 
               
              Strength[idx] =  ((abs( list0_mv[blk_x][blk_y][0] - list0_mv[blk_x2][blk_y2][0]) >= 4) | 
                (abs( list0_mv[blk_x][blk_y][1] - list0_mv[blk_x2][blk_y2][1]) >= mvlimit ) | 
                (abs( list1_mv[blk_x][blk_y][0] - list1_mv[blk_x2][blk_y2][0]) >= 4) | 
                (abs( list1_mv[blk_x][blk_y][1] - list1_mv[blk_x2][blk_y2][1]) >= mvlimit)) 
                && 
                ((abs( list0_mv[blk_x][blk_y][0] - list1_mv[blk_x2][blk_y2][0]) >= 4) | 
                (abs( list0_mv[blk_x][blk_y][1] - list1_mv[blk_x2][blk_y2][1]) >= mvlimit) | 
                (abs( list1_mv[blk_x][blk_y][0] - list0_mv[blk_x2][blk_y2][0]) >= 4) | 
                (abs( list1_mv[blk_x][blk_y][1] - list0_mv[blk_x2][blk_y2][1]) >= mvlimit)); 
            }        
          } 
          else  
          { 
            Strength[idx] = 1;         
          }    
        } 
        else   
        { // P slice 
          int64 ref_p0,ref_q0;       
          ref_p0 = list0_refIdxArr[blk_x][blk_y]<0 ? -1 : list0_refPicIdArr[blk_x][blk_y]; 
          ref_q0 = list0_refIdxArr[blk_x2][blk_y2]<0 ? -1 : list0_refPicIdArr[blk_x2][blk_y2]; 
          Strength[idx] =  (ref_p0 != ref_q0 ) | 
            (abs( list0_mv[blk_x][blk_y][0] - list0_mv[blk_x2][blk_y2][0]) >= 4 ) | 
            (abs( list0_mv[blk_x][blk_y][1] - list0_mv[blk_x2][blk_y2][1]) >= mvlimit ); 
        } 
      } 
    } 
  } 
} 
 
 
/*! 
 ***************************************************************************************** 
 * \brief 
 *    Filters one edge of 16 (luma) or 8 (chroma) pel 
 ***************************************************************************************** 
 */ 
void EdgeLoop(byte* SrcPtr,byte Strength[4],int QP, 
              int AlphaC0Offset, int BetaOffset, int dir,int width,int yuv) 
{ 
  int      pel, ap = 0, aq = 0, PtrInc, Strng ; 
  int      inc, inc2, inc3, inc4 ; 
  int      C0, c0, Delta, dif, AbsDelta ; 
  int      L2 = 0, L1, L0, R0, R1, R2 = 0, RL0 ; 
  int      Alpha = 0, Beta = 0 ; 
  byte*    ClipTab = NULL;    
  int      small_gap; 
  int      indexA, indexB; 
   
   
  PtrInc  = dir?      1 : width ; 
  inc     = dir?  width : 1 ;                     // vertical filtering increment to next pixel is 1 else width 
  inc2    = inc<<1 ;     
  inc3    = inc + inc2 ;     
  inc4    = inc<<2 ; 
   
  for( pel=0 ; pel<16 ; pel++ ) 
  { 
    if(!(pel&3)) 
    { 
      indexA = Clip3(0, MAX_QP, QP + AlphaC0Offset); 
      indexB = Clip3(0, MAX_QP, QP + BetaOffset); 
       
      Alpha=ALPHA_TABLE[indexA]; 
      Beta=BETA_TABLE[indexB];   
      ClipTab=CLIP_TAB[indexA]; 
    } 
    if( (Strng = Strength[pel >> 2]) ) 
    { 
      L0  = SrcPtr [-inc ] ; 
      R0  = SrcPtr [    0] ; 
      AbsDelta  = abs( Delta = R0 - L0 )  ; 
       
      if( AbsDelta < Alpha ) 
      { 
        C0  = ClipTab[ Strng ] ; 
        L1  = SrcPtr[-inc2] ; 
        R1  = SrcPtr[ inc ] ; 
        if( ((abs( R0 - R1) - Beta )  & (abs(L0 - L1) - Beta )) < 0  )  
        { 
          if( !yuv) 
          { 
            L2  = SrcPtr[-inc3] ; 
            R2  = SrcPtr[ inc2] ; 
            aq  = (abs( R0 - R2) - Beta ) < 0  ; 
            ap  = (abs( L0 - L2) - Beta ) < 0  ; 
          } 
           
          RL0             = L0 + R0 ; 
           
          if(Strng == 4 )    // INTRA strong filtering 
          { 
            if( yuv)  // Chroma 
            { 
              SrcPtr[   0 ] = ((R1 << 1) + R0 + L1 + 2) >> 2;  
              SrcPtr[-inc ] = ((L1 << 1) + L0 + R1 + 2) >> 2;                                            
            } 
            else  // Luma 
            { 
              small_gap = (AbsDelta < ((Alpha >> 2) + 2)); 
               
              aq &= small_gap; 
              ap &= small_gap; 
               
              SrcPtr[   0 ]   = aq ? ( L1 + ((R1 + RL0) << 1) +  SrcPtr[ inc2] + 4) >> 3 : ((R1 << 1) + R0 + L1 + 2) >> 2 ; 
              SrcPtr[-inc ]   = ap ? ( R1 + ((L1 + RL0) << 1) +  SrcPtr[-inc3] + 4) >> 3 : ((L1 << 1) + L0 + R1 + 2) >> 2 ; 
               
              SrcPtr[ inc ] =   aq  ? ( SrcPtr[ inc2] + R0 + R1 + L0 + 2) >> 2 : SrcPtr[ inc ]; 
              SrcPtr[-inc2] =   ap  ? ( SrcPtr[-inc3] + L1 + L0 + R0 + 2) >> 2 : SrcPtr[-inc2]; 
               
              SrcPtr[ inc2] = aq ? (((SrcPtr[ inc3] + SrcPtr[ inc2]) <<1) + SrcPtr[ inc2] + R1 + RL0 + 4) >> 3 : R2; 
              SrcPtr[-inc3] = ap ? (((SrcPtr[-inc4] + SrcPtr[-inc3]) <<1) + SrcPtr[-inc3] + L1 + RL0 + 4) >> 3 : L2; 
            } 
          } 
          else                                                                                   // normal filtering 
          { 
            c0               = yuv? (C0+1):(C0 + ap + aq) ; 
            dif              = Clip3( -c0, c0, ( (Delta << 2) + (L1 - R1) + 4) >> 3 ) ; 
            SrcPtr[  -inc ]  = Clip3(0, 255, L0 + dif) ; 
            SrcPtr[     0 ]  = Clip3(0, 255, R0 - dif) ; 
             
            if( !yuv ) 
            { 
              if( ap ) 
                SrcPtr[-inc2] += Clip3( -C0,  C0, ( L2 + ((RL0 + 1) >> 1) - (L1<<1)) >> 1 ) ; 
              if( aq  ) 
                SrcPtr[  inc] += Clip3( -C0,  C0, ( R2 + ((RL0 + 1) >> 1) - (R1<<1)) >> 1 ) ; 
            } ; 
          } ; 
        } ;  
      } ; 
      SrcPtr += PtrInc ;      // Increment to next set of pixel 
      pel    += yuv ; 
    }  
    else 
    { 
      SrcPtr += PtrInc << (2 - yuv) ; 
      pel    += 3 ; 
    }  ; 
  } 
}