mv-search.c

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  {
    pic_block_y          = img->field_block_y + (mb_y>>2);
    mb_available_up      = (img->field_mb_y == 0          ) ? 0 : (img->mb_data[mb_nr].slice_nr == img->mb_data[mb_nr-mb_width  ].slice_nr);
    mb_available_left    = (img->mb_x == 0          ) ? 0 : (img->mb_data[mb_nr].slice_nr == img->mb_data[mb_nr-1         ].slice_nr);
    mb_available_upleft  = (img->mb_x == 0 ||
                            img->field_mb_y == 0          ) ? 0 : (img->mb_data[mb_nr].slice_nr == img->mb_data[mb_nr-mb_width-1].slice_nr);
    mb_available_upright = (img->mb_x >= mb_width-1 ||
                            img->field_mb_y == 0          ) ? 0 : (img->mb_data[mb_nr].slice_nr == img->mb_data[mb_nr-mb_width+1].slice_nr);
  }
  
  if(input->InterlaceCodingOption >= MB_CODING && mb_adaptive)
  {
    if(img->field_mode && !img->top_field)
      mb_available_upright=0; // set mb_available_upright to 0 for bottom MBs in a MB pair
    else if(!img->field_mode && img->mb_y%2)
      mb_available_upright=0; // set mb_available_upright to 0 for bottom MBs in a MB pair

  }

  /* D B C */
  /* A X   */
  
  /* 1 A, B, D are set to 0 if unavailable       */
  /* 2 If C is not available it is replaced by D */
  block_available_up   = mb_available_up   || (mb_y > 0);
  block_available_left = mb_available_left || (mb_x > 0);

  if (mb_y > 0)
  {
    if (mb_x < 8)  // first column of 8x8 blocks
    {
      if (mb_y==8)
      {
        if (blockshape_x == 16)      block_available_upright = 0;
        else                         block_available_upright = 1;
      }
      else
      {
        if (mb_x+blockshape_x != 8)  block_available_upright = 1;
        else                         block_available_upright = 0;
      }
    }
    else
    {
      if (mb_x+blockshape_x != 16)   block_available_upright = 1;
      else                           block_available_upright = 0;
    }
  }
  else if (mb_x+blockshape_x != MB_BLOCK_SIZE)
  {
    block_available_upright = block_available_up;
  }
  else
  {
    block_available_upright = mb_available_upright;
  }
  
  if (mb_x > 0)
  {
    block_available_upleft = (mb_y > 0 ? 1 : block_available_up);
  }
  else if (mb_y > 0)
  {
    block_available_upleft = block_available_left;
  }
  else
  {
    block_available_upleft = mb_available_upleft;
  }
  
//  if(input->InterlaceCodingOption >= MB_CODING && mb_adaptive)
//    block_available_upright = 0;      // temp fix for MB level field/frame coding

  mvPredType = MVPRED_MEDIAN;
  rFrameL    = block_available_left    ? refFrArr[pic_block_y]  [pic_block_x-1] : -1;
  rFrameU    = block_available_up      ? refFrArr[pic_block_y-1][pic_block_x]   : -1;
  rFrameUR   = block_available_upright ? refFrArr[pic_block_y-1][pic_block_x+blockshape_x/4] :
               block_available_upleft  ? refFrArr[pic_block_y-1][pic_block_x-1] : -1;
  
  
  
  /* Prediction if only one of the neighbors uses the reference frame
  * we are checking
  */
  
  if(rFrameL == ref_frame && rFrameU != ref_frame && rFrameUR != ref_frame)
    mvPredType = MVPRED_L;
  else if(rFrameL != ref_frame && rFrameU == ref_frame && rFrameUR != ref_frame)
    mvPredType = MVPRED_U;
  else if(rFrameL != ref_frame && rFrameU != ref_frame && rFrameUR == ref_frame)
    mvPredType = MVPRED_UR;
  // Directional predictions 
  else if(blockshape_x == 8 && blockshape_y == 16)
  {
    if(mb_x == 0)
    {
      if(rFrameL == ref_frame)
        mvPredType = MVPRED_L;
    }
    else
    {
      if(rFrameUR == ref_frame)
        mvPredType = MVPRED_UR;
    }
  }
  else if(blockshape_x == 16 && blockshape_y == 8)
  {
    if(mb_y == 0)
    {
      if(rFrameU == ref_frame)
        mvPredType = MVPRED_U;
    }
    else
    {
      if(rFrameL == ref_frame)
        mvPredType = MVPRED_L;
    }
  }
  
#define MEDIAN(a,b,c)  (a>b?a>c?b>c?b:c:a:b>c?a>c?a:c:b)
  
  for (hv=0; hv < 2; hv++)
  {
    /*mv_a = block_available_left    ? tmp_mv[hv][pic_block_y  ][4+pic_block_x-1]              : 0;
    mv_b = block_available_up      ? tmp_mv[hv][pic_block_y-1][4+pic_block_x]                : 0;
    mv_d = block_available_upleft  ? tmp_mv[hv][pic_block_y-1][4+pic_block_x-1]              : 0;
    mv_c = block_available_upright ? tmp_mv[hv][pic_block_y-1][4+pic_block_x+blockshape_x/4] : mv_d;*/
    currMB->nbmv[0][hv]=mv_a = block_available_left    ? tmp_mv[hv][pic_block_y  ][4+pic_block_x-1]              : 0;
    currMB->nbmv[1][hv]=mv_b = block_available_up      ? tmp_mv[hv][pic_block_y-1][4+pic_block_x]                : 0;
    currMB->nbmv[2][hv]=mv_d = block_available_upleft  ? tmp_mv[hv][pic_block_y-1][4+pic_block_x-1]              : 0;
    currMB->nbmv[3][hv]=mv_c = block_available_upright ? tmp_mv[hv][pic_block_y-1][4+pic_block_x+blockshape_x/4] : mv_d;

    switch (mvPredType)
    {
    case MVPRED_MEDIAN:
      if(!(block_available_upleft || block_available_up || block_available_upright))
        pred_vec = mv_a;
      else
        pred_vec = MEDIAN (mv_a, mv_b, mv_c);
      break;
      
    case MVPRED_L:
      pred_vec = mv_a;
      break;
    case MVPRED_U:
      pred_vec = mv_b;
      break;
    case MVPRED_UR:
      pred_vec = mv_c;
      break;
    default:
      break;
    }

    pmv[hv] = pred_vec;
  }
#undef MEDIAN
}


/*!
 ************************************************************************
 * \brief
 *    Initialize the motion search
 ************************************************************************
 */
void
Init_Motion_Search_Module ()
{
  int bits, i, imin, imax, k, l;

  int search_range               = input->search_range;
  int number_of_reference_frames = img->buf_cycle;
  int max_search_points          = (2*search_range+1)*(2*search_range+1);
  int max_ref_bits               = 1 + 2 * (int)floor(log(max(16,number_of_reference_frames+1)) / log(2) + 1e-10);
  int max_ref                    = (1<<((max_ref_bits>>1)+1))-1;
  int number_of_subpel_positions = 4 * (2*search_range+3);
  int max_mv_bits                = 3 + 2 * (int)ceil (log(number_of_subpel_positions+1) / log(2) + 1e-10);
  max_mvd                        = (1<<( max_mv_bits >>1)   )-1;


  //=====   CREATE ARRAYS   =====
  //-----------------------------
  if ((spiral_search_x = (int*)calloc(max_search_points, sizeof(int))) == NULL)
    no_mem_exit("Init_Motion_Search_Module: spiral_search_x");
  if ((spiral_search_y = (int*)calloc(max_search_points, sizeof(int))) == NULL)
    no_mem_exit("Init_Motion_Search_Module: spiral_search_y");
  if ((mvbits = (int*)calloc(2*max_mvd+1, sizeof(int))) == NULL)
    no_mem_exit("Init_Motion_Search_Module: mvbits");
  if ((refbits = (int*)calloc(max_ref, sizeof(int))) == NULL)
    no_mem_exit("Init_Motion_Search_Module: refbits");
  if ((byte_abs = (int*)calloc(512, sizeof(int))) == NULL)
    no_mem_exit("Init_Motion_Search_Module: byte_abs");
  get_mem3Dint (&motion_cost, 8, 2*(img->buf_cycle+1), 4);

  //--- set array offsets ---
  mvbits   += max_mvd;
  byte_abs += 256;


  //=====   INIT ARRAYS   =====
  //---------------------------
  //--- init array: motion vector bits ---
  mvbits[0] = 1;
  for (bits=3; bits<=max_mv_bits; bits+=2)
  {
    imax = 1    << (bits >> 1);
    imin = imax >> 1;

    for (i = imin; i < imax; i++)   mvbits[-i] = mvbits[i] = bits;
  }
  //--- init array: reference frame bits ---
  refbits[0] = 1;
  for (bits=3; bits<=max_ref_bits; bits+=2)
  {
    imax = (1   << ((bits >> 1) + 1)) - 1;
    imin = imax >> 1;

    for (i = imin; i < imax; i++)   refbits[i] = bits;
  }
  //--- init array: absolute value ---
  byte_abs[0] = 0;
  for (i=1; i<256; i++)   byte_abs[i] = byte_abs[-i] = i;
  //--- init array: search pattern ---
  spiral_search_x[0] = spiral_search_y[0] = 0;
  for (k=1, l=1; l<=max(1,search_range); l++)
  {
    for (i=-l+1; i< l; i++)
    {
      spiral_search_x[k] =  i;  spiral_search_y[k++] = -l;
      spiral_search_x[k] =  i;  spiral_search_y[k++] =  l;
    }
    for (i=-l;   i<=l; i++)
    {
      spiral_search_x[k] = -l;  spiral_search_y[k++] =  i;
      spiral_search_x[k] =  l;  spiral_search_y[k++] =  i;
    }
  }

#ifdef _FAST_FULL_ME_
  InitializeFastFullIntegerSearch ();
#endif
}


/*!
 ************************************************************************
 * \brief
 *    Free memory used by motion search
 ************************************************************************
 */
void
Clear_Motion_Search_Module ()
{
  //--- correct array offset ---
  mvbits   -= max_mvd;
  byte_abs -= 256;

  //--- delete arrays ---
  free (spiral_search_x);
  free (spiral_search_y);
  free (mvbits);
  free (refbits);
  free (byte_abs);
  free_mem3Dint (motion_cost, 8);

#ifdef _FAST_FULL_ME_
  ClearFastFullIntegerSearch ();
#endif
}



/*!
 ***********************************************************************
 * \brief
 *    Full pixel block motion search
 ***********************************************************************
 */
int                                               //  ==> minimum motion cost after search
FullPelBlockMotionSearch (pel_t**   orig_pic,     // <--  original pixel values for the AxB block
                          int       ref,          // <--  reference frame (0... or -1 (backward))
                          int       pic_pix_x,    // <--  absolute x-coordinate of regarded AxB block
                          int       pic_pix_y,    // <--  absolute y-coordinate of regarded AxB block
                          int       blocktype,    // <--  block type (1-16x16 ... 7-4x4)
                          int       pred_mv_x,    // <--  motion vector predictor (x) in sub-pel units
                          int       pred_mv_y,    // <--  motion vector predictor (y) in sub-pel units
                          int*      mv_x,         // <--> in: search center (x) / out: motion vector (x) - in pel units
                          int*      mv_y,         // <--> in: search center (y) / out: motion vector (y) - in pel units
                          int       search_range, // <--  1-d search range in pel units
                          int       min_mcost,    // <--  minimum motion cost (cost for center or huge value)
                          double    lambda)       // <--  lagrangian parameter for determining motion cost
{
  int   pos, cand_x, cand_y, y, x4, mcost;
  pel_t *orig_line, *ref_line;
  pel_t *(*get_ref_line)(int, pel_t*, int, int);

  pel_t*  ref_pic       = img->type==B_IMG? Refbuf11 [ref+((mref==mref_fld)) +1] : Refbuf11[ref];
  int   best_pos      = 0;                                        // position with minimum motion cost
  int   max_pos       = (2*search_range+1)*(2*search_range+1);    // number of search positions
  int   lambda_factor = LAMBDA_FACTOR (lambda);                   // factor for determining lagragian motion cost
  int   blocksize_y   = input->blc_size[blocktype][1];            // vertical block size
  int   blocksize_x   = input->blc_size[blocktype][0];            // horizontal block size
  int   blocksize_x4  = blocksize_x >> 2;                         // horizontal block size in 4-pel units
  int   pred_x        = (pic_pix_x << 2) + pred_mv_x;       // predicted position x (in sub-pel units)
  int   pred_y        = (pic_pix_y << 2) + pred_mv_y;       // predicted position y (in sub-pel units)
  int   center_x      = pic_pix_x + *mv_x;                        // center position x (in pel units)
  int   center_y      = pic_pix_y + *mv_y;                        // center position y (in pel units)
  int   check_for_00  = (blocktype==1 && !input->rdopt && img->type!=B_IMG && ref==0);

  //===== set function for getting reference picture lines =====
  if ((center_x > search_range) && (center_x < img->width -1-search_range-blocksize_x) &&
      (center_y > search_range) && (center_y < img->height-1-search_range-blocksize_y)   )
  {
     get_ref_line = FastLineX;
  }
  else
  {
     get_ref_line = UMVLineX;
  }


  //===== loop over all search positions =====
  for (pos=0; pos<max_pos; pos++)
  {
    //--- set candidate position (absolute position in pel units) ---
    cand_x = center_x + spiral_search_x[pos];
    cand_y = center_y + spiral_search_y[pos];

    //--- initialize motion cost (cost for motion vector) and check ---
    mcost = MV_COST (lambda_factor, 2, cand_x, cand_y, pred_x, pred_y);
    if (check_for_00 && cand_x==pic_pix_x && cand_y==pic_pix_y)
    {
      mcost -= WEIGHTED_COST (lambda_factor, 16);
    }
    if (mcost >= min_mcost)   continue;

    //--- add residual cost to motion cost ---
    for (y=0; y<blocksize_y; y++)
    {
      ref_line  = get_ref_line (blocksize_x, ref_pic, cand_y+y, cand_x);
      orig_line = orig_pic [y];

      for (x4=0; x4<blocksize_x4; x4++)
      {
        mcost += byte_abs[ *orig_line++ - *ref_line++ ];
        mcost += byte_abs[ *orig_line++ - *ref_line++ ];
        mcost += byte_abs[ *orig_line++ - *ref_line++ ];
        mcost += byte_abs[ *orig_line++ - *ref_line++ ];
      }

      if (mcost >= min_mcost)
      {
        break;
      }
    }

    //--- check if motion cost is less than minimum cost ---
    if (mcost < min_mcost)
    {
      best_pos  = pos;
      min_mcost = mcost;
    }
  }


  //===== set best motion vector and return minimum motion cost =====
  if (best_pos)
  {
    *mv_x += spiral_search_x[best_pos];
    *mv_y += spiral_search_y[best_pos];
  }
  return min_mcost;
}


#ifdef _FAST_FULL_ME_
/*!
 ***********************************************************************
 * \brief
 *    Fast Full pixel block motion search
 ***********************************************************************
 */