vp9_mcomp.c

/*
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include <limits.h>
#include <math.h>
#include <stdio.h>

#include "./vpx_config.h"

#include "vpx_mem/vpx_mem.h"

#include "vp9/common/vp9_findnearmv.h"
#include "vp9/common/vp9_common.h"

#include "vp9/encoder/vp9_onyx_int.h"
#include "vp9/encoder/vp9_mcomp.h"

// #define NEW_DIAMOND_SEARCH

void vp9_clamp_mv_min_max(MACROBLOCK *x, MV *mv) {
  const int col_min = (mv->col >> 3) - MAX_FULL_PEL_VAL + (mv->col & 7 ? 1 : 0);
  const int row_min = (mv->row >> 3) - MAX_FULL_PEL_VAL + (mv->row & 7 ? 1 : 0);
  const int col_max = (mv->col >> 3) + MAX_FULL_PEL_VAL;
  const int row_max = (mv->row >> 3) + MAX_FULL_PEL_VAL;

  // Get intersection of UMV window and valid MV window to reduce # of checks
  // in diamond search.
  if (x->mv_col_min < col_min)
    x->mv_col_min = col_min;
  if (x->mv_col_max > col_max)
    x->mv_col_max = col_max;
  if (x->mv_row_min < row_min)
    x->mv_row_min = row_min;
  if (x->mv_row_max > row_max)
    x->mv_row_max = row_max;
}

int vp9_init_search_range(VP9_COMP *cpi, int size) {
  int sr = 0;

  // Minimum search size no matter what the passed in value.
  size = MAX(16, size);

  while ((size << sr) < MAX_FULL_PEL_VAL)
    sr++;

  if (sr)
    sr--;

  sr += cpi->sf.reduce_first_step_size;
  sr = MIN(sr, (cpi->sf.max_step_search_steps - 2));
  return sr;
}

int vp9_mv_bit_cost(int_mv *mv, int_mv *ref, int *mvjcost, int *mvcost[2],
                    int weight) {
  MV v;
  v.row = mv->as_mv.row - ref->as_mv.row;
  v.col = mv->as_mv.col - ref->as_mv.col;
  return ROUND_POWER_OF_TWO((mvjcost[vp9_get_mv_joint(&v)] +
                             mvcost[0][v.row] +
                             mvcost[1][v.col]) * weight, 7);
}

static int mv_err_cost(int_mv *mv, int_mv *ref, int *mvjcost, int *mvcost[2],
                       int error_per_bit) {
  if (mvcost) {
    MV v;
    v.row = mv->as_mv.row - ref->as_mv.row;
    v.col = mv->as_mv.col - ref->as_mv.col;
    return ROUND_POWER_OF_TWO((mvjcost[vp9_get_mv_joint(&v)] +
                               mvcost[0][v.row] +
                               mvcost[1][v.col]) * error_per_bit, 13);
  }
  return 0;
}

static int mvsad_err_cost(int_mv *mv, int_mv *ref, int *mvjsadcost,
                          int *mvsadcost[2], int error_per_bit) {
  if (mvsadcost) {
    MV v;
    v.row = mv->as_mv.row - ref->as_mv.row;
    v.col = mv->as_mv.col - ref->as_mv.col;
    return ROUND_POWER_OF_TWO((mvjsadcost[vp9_get_mv_joint(&v)] +
                               mvsadcost[0][v.row] +
                               mvsadcost[1][v.col]) * error_per_bit, 8);
  }
  return 0;
}

void vp9_init_dsmotion_compensation(MACROBLOCK *x, int stride) {
  int len;
  int search_site_count = 0;

  // Generate offsets for 4 search sites per step.
  x->ss[search_site_count].mv.col = 0;
  x->ss[search_site_count].mv.row = 0;
  x->ss[search_site_count].offset = 0;
  search_site_count++;

  for (len = MAX_FIRST_STEP; len > 0; len /= 2) {
    // Compute offsets for search sites.
    x->ss[search_site_count].mv.col = 0;
    x->ss[search_site_count].mv.row = -len;
    x->ss[search_site_count].offset = -len * stride;
    search_site_count++;

    // Compute offsets for search sites.
    x->ss[search_site_count].mv.col = 0;
    x->ss[search_site_count].mv.row = len;
    x->ss[search_site_count].offset = len * stride;
    search_site_count++;

    // Compute offsets for search sites.
    x->ss[search_site_count].mv.col = -len;
    x->ss[search_site_count].mv.row = 0;
    x->ss[search_site_count].offset = -len;
    search_site_count++;

    // Compute offsets for search sites.
    x->ss[search_site_count].mv.col = len;
    x->ss[search_site_count].mv.row = 0;
    x->ss[search_site_count].offset = len;
    search_site_count++;
  }

  x->ss_count = search_site_count;
  x->searches_per_step = 4;
}

void vp9_init3smotion_compensation(MACROBLOCK *x, int stride) {
  int len, ss_count = 1;

  x->ss[0].mv.col = x->ss[0].mv.row = 0;
  x->ss[0].offset = 0;

  for (len = MAX_FIRST_STEP; len > 0; len /= 2) {
    // Generate offsets for 8 search sites per step.
    const MV ss_mvs[8] = {
      { 0,   -len}, {0,    len}, {-len,  0  }, {len,  0  },
      {-len, -len}, {len, -len}, {-len,  len}, {len,  len}
    };
    int i;
    for (i = 0; i < 8; ++i) {
      search_site *const ss = &x->ss[ss_count++];
      ss->mv = ss_mvs[i];
      ss->offset = ss->mv.row * stride + ss->mv.col;
    }
  }

  x->ss_count = ss_count;
  x->searches_per_step = 8;
}

/*
 * To avoid the penalty for crossing cache-line read, preload the reference
 * area in a small buffer, which is aligned to make sure there won't be crossing
 * cache-line read while reading from this buffer. This reduced the cpu
 * cycles spent on reading ref data in sub-pixel filter functions.
 * TODO: Currently, since sub-pixel search range here is -3 ~ 3, copy 22 rows x
 * 32 cols area that is enough for 16x16 macroblock. Later, for SPLITMV, we
 * could reduce the area.
 */

/* estimated cost of a motion vector (r,c) */
#define MVC(r, c)                                       \
    (mvcost ?                                           \
     ((mvjcost[((r) != rr) * 2 + ((c) != rc)] +         \
       mvcost[0][((r) - rr)] + mvcost[1][((c) - rc)]) * \
      error_per_bit + 4096) >> 13 : 0)


#define SP(x) (((x) & 7) << 1)  // convert motion vector component to offset
                                // for svf calc

#define IFMVCV(r, c, s, e)                                \
    if (c >= minc && c <= maxc && r >= minr && r <= maxr) \
      s                                                   \
    else                                                  \
      e;

/* pointer to predictor base of a motionvector */
#define PRE(r, c) (y + (((r) >> 3) * y_stride + ((c) >> 3) -(offset)))

/* returns subpixel variance error function */
#define DIST(r, c) \
    vfp->svf(PRE(r, c), y_stride, SP(c), SP(r), z, src_stride, &sse)

/* checks if (r, c) has better score than previous best */
#define CHECK_BETTER(v, r, c) \
    IFMVCV(r, c, {                                                       \
      thismse = (DIST(r, c));                                            \
      if ((v = MVC(r, c) + thismse) < besterr) {                         \
        besterr = v;                                                     \
        br = r;                                                          \
        bc = c;                                                          \
        *distortion = thismse;                                           \
        *sse1 = sse;                                                     \
      }                                                                  \
    },                                                                   \
    v = INT_MAX;)

#define FIRST_LEVEL_CHECKS                              \
  {                                                     \
    unsigned int left, right, up, down, diag;           \
    CHECK_BETTER(left, tr, tc - hstep);                 \
    CHECK_BETTER(right, tr, tc + hstep);                \
    CHECK_BETTER(up, tr - hstep, tc);                   \
    CHECK_BETTER(down, tr + hstep, tc);                 \
    whichdir = (left < right ? 0 : 1) +                 \
               (up < down ? 0 : 2);                     \
    switch (whichdir) {                                 \
      case 0:                                           \
        CHECK_BETTER(diag, tr - hstep, tc - hstep);     \
        break;                                          \
      case 1:                                           \
        CHECK_BETTER(diag, tr - hstep, tc + hstep);     \
        break;                                          \
      case 2:                                           \
        CHECK_BETTER(diag, tr + hstep, tc - hstep);     \
        break;                                          \
      case 3:                                           \
        CHECK_BETTER(diag, tr + hstep, tc + hstep);     \
        break;                                          \
    }                                                   \
  }

#define SECOND_LEVEL_CHECKS                             \
  {                                                     \
    int kr, kc;                                         \
    unsigned int second;                                \
    if (tr != br && tc != bc) {                         \
      kr = br - tr;                                     \
      kc = bc - tc;                                     \
      CHECK_BETTER(second, tr + kr, tc + 2 * kc);       \
      CHECK_BETTER(second, tr + 2 * kr, tc + kc);       \
    } else if (tr == br && tc != bc) {                  \
      kc = bc - tc;                                     \
      CHECK_BETTER(second, tr + hstep, tc + 2 * kc);    \
      CHECK_BETTER(second, tr - hstep, tc + 2 * kc);    \
      switch (whichdir) {                               \
        case 0:                                         \
        case 1:                                         \
          CHECK_BETTER(second, tr + hstep, tc + kc);    \
          break;                                        \
        case 2:                                         \
        case 3:                                         \
          CHECK_BETTER(second, tr - hstep, tc + kc);    \
          break;                                        \
      }                                                 \
    } else if (tr != br && tc == bc) {                  \
      kr = br - tr;                                     \
      CHECK_BETTER(second, tr + 2 * kr, tc + hstep);    \
      CHECK_BETTER(second, tr + 2 * kr, tc - hstep);    \
      switch (whichdir) {                               \
        case 0:                                         \
        case 2:                                         \
          CHECK_BETTER(second, tr + kr, tc + hstep);    \
          break;                                        \
        case 1:                                         \
        case 3:                                         \
          CHECK_BETTER(second, tr + kr, tc - hstep);    \
          break;                                        \
      }                                                 \
    }                                                   \
  }

int vp9_find_best_sub_pixel_iterative(MACROBLOCK *x,
                                      int_mv *bestmv, int_mv *ref_mv,
                                      int error_per_bit,
                                      const vp9_variance_fn_ptr_t *vfp,
                                      int forced_stop,
                                      int iters_per_step,
                                      int *mvjcost, int *mvcost[2],
                                      int *distortion,
                                      unsigned int *sse1) {
  uint8_t *z = x->plane[0].src.buf;
  int src_stride = x->plane[0].src.stride;
  MACROBLOCKD *xd = &x->e_mbd;

  unsigned int besterr = INT_MAX;
  unsigned int sse;
  unsigned int whichdir;
  unsigned int halfiters = iters_per_step;
  unsigned int quarteriters = iters_per_step;
  unsigned int eighthiters = iters_per_step;
  int thismse;

  const int y_stride = xd->plane[0].pre[0].stride;
  const int offset = (bestmv->as_mv.row) * y_stride + bestmv->as_mv.col;
  uint8_t *y = xd->plane[0].pre[0].buf + offset;

  int rr = ref_mv->as_mv.row;
  int rc = ref_mv->as_mv.col;
  int br = bestmv->as_mv.row * 8;
  int bc = bestmv->as_mv.col * 8;
  int hstep = 4;
  const int minc = MAX(x->mv_col_min * 8, ref_mv->as_mv.col - MV_MAX);
  const int maxc = MIN(x->mv_col_max * 8, ref_mv->as_mv.col + MV_MAX);
  const int minr = MAX(x->mv_row_min * 8, ref_mv->as_mv.row - MV_MAX);
  const int maxr = MIN(x->mv_row_max * 8, ref_mv->as_mv.row + MV_MAX);

  int tr = br;
  int tc = bc;

  // central mv
  bestmv->as_mv.row <<= 3;
  bestmv->as_mv.col <<= 3;

  // calculate central point error
  besterr = vfp->vf(y, y_stride, z, src_stride, sse1);
  *distortion = besterr;
  besterr += mv_err_cost(bestmv, ref_mv, mvjcost, mvcost, error_per_bit);

  // TODO: Each subsequent iteration checks at least one point in
  // common with the last iteration could be 2 ( if diag selected)
  while (halfiters--) {
    // 1/2 pel
    FIRST_LEVEL_CHECKS;
    // no reason to check the same one again.
    if (tr == br && tc == bc)
      break;
    tr = br;
    tc = bc;
  }

  // TODO: Each subsequent iteration checks at least one point in common with
  // the last iteration could be 2 ( if diag selected) 1/4 pel

  // Note forced_stop: 0 - full, 1 - qtr only, 2 - half only
  if (forced_stop != 2) {
    hstep >>= 1;
    while (quarteriters--) {
      FIRST_LEVEL_CHECKS;
      // no reason to check the same one again.
      if (tr == br && tc == bc)
        break;
      tr = br;
      tc = bc;
    }
  }

  if (xd->allow_high_precision_mv && vp9_use_mv_hp(&ref_mv->as_mv) &&
      forced_stop == 0) {
    hstep >>= 1;
    while (eighthiters--) {
      FIRST_LEVEL_CHECKS;
      // no reason to check the same one again.
      if (tr == br && tc == bc)
        break;
      tr = br;
      tc = bc;
    }
  }

  bestmv->as_mv.row = br;
  bestmv->as_mv.col = bc;

  if ((abs(bestmv->as_mv.col - ref_mv->as_mv.col) > (MAX_FULL_PEL_VAL << 3)) ||
      (abs(bestmv->as_mv.row - ref_mv->as_mv.row) > (MAX_FULL_PEL_VAL << 3)))
    return INT_MAX;

  return besterr;
}

int vp9_find_best_sub_pixel_tree(MACROBLOCK *x,
                                 int_mv *bestmv, int_mv *ref_mv,
                                 int error_per_bit,
                                 const vp9_variance_fn_ptr_t *vfp,
                                 int forced_stop,
                                 int iters_per_step,
                                 int *mvjcost, int *mvcost[2],
                                 int *distortion,
                                 unsigned int *sse1) {
  uint8_t *z = x->plane[0].src.buf;
  const int src_stride = x->plane[0].src.stride;
  MACROBLOCKD *xd = &x->e_mbd;
  unsigned int besterr = INT_MAX;
  unsigned int sse;
  unsigned int whichdir;
  int thismse;
  unsigned int halfiters = iters_per_step;
  unsigned int quarteriters = iters_per_step;
  unsigned int eighthiters = iters_per_step;

  const int y_stride = xd->plane[0].pre[0].stride;
  const int offset = bestmv->as_mv.row * y_stride + bestmv->as_mv.col;
  uint8_t *y = xd->plane[0].pre[0].buf + offset;

  int rr = ref_mv->as_mv.row;
  int rc = ref_mv->as_mv.col;
  int br = bestmv->as_mv.row * 8;
  int bc = bestmv->as_mv.col * 8;
  int hstep = 4;
  const int minc = MAX(x->mv_col_min * 8, ref_mv->as_mv.col - MV_MAX);
  const int maxc = MIN(x->mv_col_max * 8, ref_mv->as_mv.col + MV_MAX);
  const int minr = MAX(x->mv_row_min * 8, ref_mv->as_mv.row - MV_MAX);
  const int maxr = MIN(x->mv_row_max * 8, ref_mv->as_mv.row + MV_MAX);

  int tr = br;
  int tc = bc;

  // central mv
  bestmv->as_mv.row *= 8;
  bestmv->as_mv.col *= 8;

  // calculate central point error
  besterr = vfp->vf(y, y_stride, z, src_stride, sse1);
  *distortion = besterr;
  besterr += mv_err_cost(bestmv, ref_mv, mvjcost, mvcost, error_per_bit);

  // 1/2 pel
  FIRST_LEVEL_CHECKS;
  if (halfiters > 1) {
    SECOND_LEVEL_CHECKS;
  }
  tr = br;
  tc = bc;

  // Note forced_stop: 0 - full, 1 - qtr only, 2 - half only
  if (forced_stop != 2) {
    hstep >>= 1;
    FIRST_LEVEL_CHECKS;
    if (quarteriters > 1) {
      SECOND_LEVEL_CHECKS;
    }
    tr = br;
    tc = bc;
  }

  if (xd->allow_high_precision_mv && vp9_use_mv_hp(&ref_mv->as_mv) &&
      forced_stop == 0) {
    hstep >>= 1;
    FIRST_LEVEL_CHECKS;
    if (eighthiters > 1) {
      SECOND_LEVEL_CHECKS;
    }
    tr = br;
    tc = bc;
  }

  bestmv->as_mv.row = br;
  bestmv->as_mv.col = bc;

  if ((abs(bestmv->as_mv.col - ref_mv->as_mv.col) > (MAX_FULL_PEL_VAL << 3)) ||
      (abs(bestmv->as_mv.row - ref_mv->as_mv.row) > (MAX_FULL_PEL_VAL << 3)))
    return INT_MAX;

  return besterr;
}

#undef DIST
/* returns subpixel variance error function */
#define DIST(r, c) \
    vfp->svaf(PRE(r, c), y_stride, SP(c), SP(r), \
              z, src_stride, &sse, second_pred)

int vp9_find_best_sub_pixel_comp_iterative(MACROBLOCK *x,
                                           int_mv *bestmv, int_mv *ref_mv,
                                           int error_per_bit,
                                           const vp9_variance_fn_ptr_t *vfp,
                                           int forced_stop,
                                           int iters_per_step,
                                           int *mvjcost, int *mvcost[2],
                                           int *distortion,
                                           unsigned int *sse1,
                                           const uint8_t *second_pred,
                                           int w, int h) {
  uint8_t *const z = x->plane[0].src.buf;
  const int src_stride = x->plane[0].src.stride;
  MACROBLOCKD *const xd = &x->e_mbd;

  unsigned int besterr = INT_MAX;
  unsigned int sse;
  unsigned int whichdir;
  unsigned int halfiters = iters_per_step;
  unsigned int quarteriters = iters_per_step;
  unsigned int eighthiters = iters_per_step;
  int thismse;

  DECLARE_ALIGNED_ARRAY(16, uint8_t, comp_pred, 64 * 64);
  const int y_stride = xd->plane[0].pre[0].stride;
  const int offset = bestmv->as_mv.row * y_stride + bestmv->as_mv.col;
  uint8_t *const y = xd->plane[0].pre[0].buf + offset;

  int rr = ref_mv->as_mv.row;
  int rc = ref_mv->as_mv.col;
  int br = bestmv->as_mv.row * 8;
  int bc = bestmv->as_mv.col * 8;
  int hstep = 4;
  const int minc = MAX(x->mv_col_min * 8, ref_mv->as_mv.col - MV_MAX);
  const int maxc = MIN(x->mv_col_max * 8, ref_mv->as_mv.col + MV_MAX);
  const int minr = MAX(x->mv_row_min * 8, ref_mv->as_mv.row - MV_MAX);
  const int maxr = MIN(x->mv_row_max * 8, ref_mv->as_mv.row + MV_MAX);

  int tr = br;
  int tc = bc;

  // central mv
  bestmv->as_mv.row *= 8;
  bestmv->as_mv.col *= 8;

  // calculate central point error
  // TODO(yunqingwang): central pointer error was already calculated in full-
  // pixel search, and can be passed in this function.
  comp_avg_pred(comp_pred, second_pred, w, h, y, y_stride);
  besterr = vfp->vf(comp_pred, w, z, src_stride, sse1);
  *distortion = besterr;
  besterr += mv_err_cost(bestmv, ref_mv, mvjcost, mvcost, error_per_bit);

  // Each subsequent iteration checks at least one point in
  // common with the last iteration could be 2 ( if diag selected)
  while (halfiters--) {
    // 1/2 pel
    FIRST_LEVEL_CHECKS;
    // no reason to check the same one again.
    if (tr == br && tc == bc)
      break;
    tr = br;
    tc = bc;
  }

  // Each subsequent iteration checks at least one point in common with
  // the last iteration could be 2 ( if diag selected) 1/4 pel

  // Note forced_stop: 0 - full, 1 - qtr only, 2 - half only
  if (forced_stop != 2) {
    hstep >>= 1;
    while (quarteriters--) {
      FIRST_LEVEL_CHECKS;
      // no reason to check the same one again.
      if (tr == br && tc == bc)
        break;
      tr = br;
      tc = bc;
    }
  }

  if (xd->allow_high_precision_mv && vp9_use_mv_hp(&ref_mv->as_mv) &&
      forced_stop == 0) {
    hstep >>= 1;
    while (eighthiters--) {
      FIRST_LEVEL_CHECKS;
      // no reason to check the same one again.
      if (tr == br && tc == bc)
        break;
      tr = br;
      tc = bc;
    }
  }
  bestmv->as_mv.row = br;
  bestmv->as_mv.col = bc;

  if ((abs(bestmv->as_mv.col - ref_mv->as_mv.col) > (MAX_FULL_PEL_VAL << 3)) ||
      (abs(bestmv->as_mv.row - ref_mv->as_mv.row) > (MAX_FULL_PEL_VAL << 3)))
    return INT_MAX;

  return besterr;
}

int vp9_find_best_sub_pixel_comp_tree(MACROBLOCK *x,
                                      int_mv *bestmv, int_mv *ref_mv,
                                      int error_per_bit,
                                      const vp9_variance_fn_ptr_t *vfp,
                                      int forced_stop,
                                      int iters_per_step,
                                      int *mvjcost, int *mvcost[2],
                                      int *distortion,
                                      unsigned int *sse1,
                                      const uint8_t *second_pred,
                                      int w, int h) {
  uint8_t *z = x->plane[0].src.buf;
  const int src_stride = x->plane[0].src.stride;
  MACROBLOCKD *xd = &x->e_mbd;
  unsigned int besterr = INT_MAX;
  unsigned int sse;
  unsigned int whichdir;
  int thismse;
  unsigned int halfiters = iters_per_step;
  unsigned int quarteriters = iters_per_step;
  unsigned int eighthiters = iters_per_step;

  DECLARE_ALIGNED_ARRAY(16, uint8_t, comp_pred, 64 * 64);
  const int y_stride = xd->plane[0].pre[0].stride;
  const int offset = (bestmv->as_mv.row) * y_stride + bestmv->as_mv.col;
  uint8_t *y = xd->plane[0].pre[0].buf + offset;

  int rr = ref_mv->as_mv.row;
  int rc = ref_mv->as_mv.col;
  int br = bestmv->as_mv.row * 8;
  int bc = bestmv->as_mv.col * 8;
  int hstep = 4;
  const int minc = MAX(x->mv_col_min * 8, ref_mv->as_mv.col - MV_MAX);
  const int maxc = MIN(x->mv_col_max * 8, ref_mv->as_mv.col + MV_MAX);
  const int minr = MAX(x->mv_row_min * 8, ref_mv->as_mv.row - MV_MAX);
  const int maxr = MIN(x->mv_row_max * 8, ref_mv->as_mv.row + MV_MAX);

  int tr = br;
  int tc = bc;

  // central mv
  bestmv->as_mv.row *= 8;
  bestmv->as_mv.col *= 8;

  // calculate central point error
  // TODO(yunqingwang): central pointer error was already calculated in full-
  // pixel search, and can be passed in this function.
  comp_avg_pred(comp_pred, second_pred, w, h, y, y_stride);
  besterr = vfp->vf(comp_pred, w, z, src_stride, sse1);
  *distortion = besterr;
  besterr += mv_err_cost(bestmv, ref_mv, mvjcost, mvcost, error_per_bit);

  // Each subsequent iteration checks at least one point in
  // common with the last iteration could be 2 ( if diag selected)
  // 1/2 pel
  FIRST_LEVEL_CHECKS;
  if (halfiters > 1) {
    SECOND_LEVEL_CHECKS;
  }
  tr = br;
  tc = bc;

  // Each subsequent iteration checks at least one point in common with
  // the last iteration could be 2 ( if diag selected) 1/4 pel

  // Note forced_stop: 0 - full, 1 - qtr only, 2 - half only
  if (forced_stop != 2) {
    hstep >>= 1;
    FIRST_LEVEL_CHECKS;
    if (quarteriters > 1) {
      SECOND_LEVEL_CHECKS;
    }
    tr = br;
    tc = bc;
  }

  if (xd->allow_high_precision_mv && vp9_use_mv_hp(&ref_mv->as_mv) &&
      forced_stop == 0) {
    hstep >>= 1;
    FIRST_LEVEL_CHECKS;
    if (eighthiters > 1) {
      SECOND_LEVEL_CHECKS;
    }
    tr = br;
    tc = bc;
  }
  bestmv->as_mv.row = br;
  bestmv->as_mv.col = bc;

  if ((abs(bestmv->as_mv.col - ref_mv->as_mv.col) > (MAX_FULL_PEL_VAL << 3)) ||
      (abs(bestmv->as_mv.row - ref_mv->as_mv.row) > (MAX_FULL_PEL_VAL << 3)))
    return INT_MAX;

  return besterr;
}

#undef MVC
#undef PRE
#undef DIST
#undef IFMVCV
#undef CHECK_BETTER
#undef SP

#define CHECK_BOUNDS(range) \
  {\
    all_in = 1;\
    all_in &= ((br-range) >= x->mv_row_min);\
    all_in &= ((br+range) <= x->mv_row_max);\
    all_in &= ((bc-range) >= x->mv_col_min);\
    all_in &= ((bc+range) <= x->mv_col_max);\
  }

#define CHECK_POINT \
  {\
    if (this_mv.as_mv.col < x->mv_col_min) continue;\
    if (this_mv.as_mv.col > x->mv_col_max) continue;\
    if (this_mv.as_mv.row < x->mv_row_min) continue;\
    if (this_mv.as_mv.row > x->mv_row_max) continue;\
  }

#define CHECK_BETTER \
  {\
    if (thissad < bestsad)\
    {\
      if (use_mvcost) \
        thissad += mvsad_err_cost(&this_mv, &fcenter_mv, \
                                  mvjsadcost, mvsadcost, \
                                  sad_per_bit);\
      if (thissad < bestsad)\
      {\
        bestsad = thissad;\
        best_site = i;\
      }\
    }\
  }

#define get_next_chkpts(list, i, n)   \
    list[0] = ((i) == 0 ? (n) - 1 : (i) - 1);  \
    list[1] = (i);                             \
    list[2] = ((i) == (n) - 1 ? 0 : (i) + 1);

#define MAX_PATTERN_SCALES         11
#define MAX_PATTERN_CANDIDATES      8  // max number of canddiates per scale
#define PATTERN_CANDIDATES_REF      3  // number of refinement candidates

// Generic pattern search function that searches over multiple scales.
// Each scale can have a different number of candidates and shape of
// candidates as indicated in the num_candidates and candidates arrays
// passed into this function
static int vp9_pattern_search(MACROBLOCK *x,
                              int_mv *ref_mv,
                              int search_param,
                              int sad_per_bit,
                              int do_init_search,
                              int do_refine,
                              const vp9_variance_fn_ptr_t *vfp,
                              int use_mvcost,
                              int_mv *center_mv, int_mv *best_mv,
                              const int num_candidates[MAX_PATTERN_SCALES],
                              const MV candidates[MAX_PATTERN_SCALES]
                                                 [MAX_PATTERN_CANDIDATES]) {
  const MACROBLOCKD* const xd = &x->e_mbd;
  static const int search_param_to_steps[MAX_MVSEARCH_STEPS] = {
    10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
  };
  int i, j, s, t;
  uint8_t *what = x->plane[0].src.buf;
  int what_stride = x->plane[0].src.stride;
  int in_what_stride = xd->plane[0].pre[0].stride;
  int br, bc;
  int_mv this_mv;
  int bestsad = INT_MAX;
  int thissad;
  uint8_t *base_offset;
  uint8_t *this_offset;
  int k = -1;
  int all_in;
  int best_site = -1;
  int_mv fcenter_mv;
  int best_init_s = search_param_to_steps[search_param];
  int *mvjsadcost = x->nmvjointsadcost;
  int *mvsadcost[2] = {x->nmvsadcost[0], x->nmvsadcost[1]};

  fcenter_mv.as_mv.row = center_mv->as_mv.row >> 3;
  fcenter_mv.as_mv.col = center_mv->as_mv.col >> 3;

  // adjust ref_mv to make sure it is within MV range
  clamp_mv(&ref_mv->as_mv,
           x->mv_col_min, x->mv_col_max, x->mv_row_min, x->mv_row_max);
  br = ref_mv->as_mv.row;
  bc = ref_mv->as_mv.col;

  // Work out the start point for the search
  base_offset = (uint8_t *)(xd->plane[0].pre[0].buf);
  this_offset = base_offset + (br * in_what_stride) + bc;
  this_mv.as_mv.row = br;
  this_mv.as_mv.col = bc;
  bestsad = vfp->sdf(what, what_stride, this_offset,
                     in_what_stride, 0x7fffffff)
            + mvsad_err_cost(&this_mv, &fcenter_mv, mvjsadcost, mvsadcost,
                             sad_per_bit);

  // Search all possible scales upto the search param around the center point
  // pick the scale of the point that is best as the starting scale of
  // further steps around it.
  if (do_init_search) {
    s = best_init_s;
    best_init_s = -1;
    for (t = 0; t <= s; ++t) {
      best_site = -1;
      CHECK_BOUNDS((1 << t))
      if (all_in) {
        for (i = 0; i < num_candidates[t]; i++) {
          this_mv.as_mv.row = br + candidates[t][i].row;
          this_mv.as_mv.col = bc + candidates[t][i].col;
          this_offset = base_offset + (this_mv.as_mv.row * in_what_stride) +
              this_mv.as_mv.col;
          thissad = vfp->sdf(what, what_stride, this_offset, in_what_stride,
                             bestsad);
          CHECK_BETTER
        }
      } else {
        for (i = 0; i < num_candidates[t]; i++) {
          this_mv.as_mv.row = br + candidates[t][i].row;
          this_mv.as_mv.col = bc + candidates[t][i].col;
          CHECK_POINT
          this_offset = base_offset + (this_mv.as_mv.row * in_what_stride) +
                        this_mv.as_mv.col;
          thissad = vfp->sdf(what, what_stride, this_offset, in_what_stride,
                             bestsad);
          CHECK_BETTER
        }
      }
      if (best_site == -1) {
        continue;
      } else {
        best_init_s = t;
        k = best_site;
      }
    }
    if (best_init_s != -1) {
      br += candidates[best_init_s][k].row;
      bc += candidates[best_init_s][k].col;
    }
  }

  // If the center point is still the best, just skip this and move to
  // the refinement step.
  if (best_init_s != -1) {
    s = best_init_s;
    best_site = -1;
    do {
      // No need to search all 6 points the 1st time if initial search was used
      if (!do_init_search || s != best_init_s) {
        CHECK_BOUNDS((1 << s))
        if (all_in) {
          for (i = 0; i < num_candidates[s]; i++) {
            this_mv.as_mv.row = br + candidates[s][i].row;
            this_mv.as_mv.col = bc + candidates[s][i].col;
            this_offset = base_offset + (this_mv.as_mv.row * in_what_stride) +
                this_mv.as_mv.col;
            thissad = vfp->sdf(what, what_stride, this_offset, in_what_stride,
                               bestsad);
            CHECK_BETTER
          }
        } else {
          for (i = 0; i < num_candidates[s]; i++) {
            this_mv.as_mv.row = br + candidates[s][i].row;
            this_mv.as_mv.col = bc + candidates[s][i].col;
            CHECK_POINT
            this_offset = base_offset + (this_mv.as_mv.row * in_what_stride) +
                          this_mv.as_mv.col;
            thissad = vfp->sdf(what, what_stride, this_offset, in_what_stride,
                               bestsad);
            CHECK_BETTER
          }
        }

        if (best_site == -1) {
          continue;
        } else {
          br += candidates[s][best_site].row;
          bc += candidates[s][best_site].col;
          k = best_site;
        }
      }

      do {
        int next_chkpts_indices[PATTERN_CANDIDATES_REF];
        best_site = -1;
        CHECK_BOUNDS((1 << s))

        get_next_chkpts(next_chkpts_indices, k, num_candidates[s]);
        if (all_in) {
          for (i = 0; i < PATTERN_CANDIDATES_REF; i++) {
            this_mv.as_mv.row = br +
                candidates[s][next_chkpts_indices[i]].row;
            this_mv.as_mv.col = bc +
                candidates[s][next_chkpts_indices[i]].col;
            this_offset = base_offset + (this_mv.as_mv.row * (in_what_stride)) +
                this_mv.as_mv.col;
            thissad = vfp->sdf(what, what_stride, this_offset, in_what_stride,
                               bestsad);
            CHECK_BETTER
          }
        } else {
          for (i = 0; i < PATTERN_CANDIDATES_REF; i++) {
            this_mv.as_mv.row = br +
                candidates[s][next_chkpts_indices[i]].row;
            this_mv.as_mv.col = bc +
                candidates[s][next_chkpts_indices[i]].col;
            CHECK_POINT
            this_offset = base_offset + (this_mv.as_mv.row * (in_what_stride)) +
                          this_mv.as_mv.col;
            thissad = vfp->sdf(what, what_stride, this_offset, in_what_stride,
                               bestsad);
            CHECK_BETTER
          }
        }

        if (best_site != -1) {
          k = next_chkpts_indices[best_site];
          br += candidates[s][k].row;
          bc += candidates[s][k].col;
        }
      } while (best_site != -1);
    } while (s--);
  }

  // Check 4 1-away neighbors if do_refine is true.
  // For most well-designed schemes do_refine will not be necessary.
  if (do_refine) {
    static const MV neighbors[4] = {
      {0, -1}, { -1, 0}, {1, 0}, {0, 1},
    };
    for (j = 0; j < 16; j++) {
      best_site = -1;
      CHECK_BOUNDS(1)
      if (all_in) {
        for (i = 0; i < 4; i++) {
          this_mv.as_mv.row = br + neighbors[i].row;
          this_mv.as_mv.col = bc + neighbors[i].col;
          this_offset = base_offset + (this_mv.as_mv.row * (in_what_stride)) +
              this_mv.as_mv.col;
          thissad = vfp->sdf(what, what_stride, this_offset, in_what_stride,
                             bestsad);
          CHECK_BETTER
        }
      } else {
        for (i = 0; i < 4; i++) {
          this_mv.as_mv.row = br + neighbors[i].row;
          this_mv.as_mv.col = bc + neighbors[i].col;
          CHECK_POINT
          this_offset = base_offset + (this_mv.as_mv.row * (in_what_stride)) +
                        this_mv.as_mv.col;
          thissad = vfp->sdf(what, what_stride, this_offset, in_what_stride,
                             bestsad);
          CHECK_BETTER
        }
          }

      if (best_site == -1) {
        break;
      } else {
        br += neighbors[best_site].row;
        bc += neighbors[best_site].col;
      }
    }
  }

  best_mv->as_mv.row = br;
  best_mv->as_mv.col = bc;

  this_offset = base_offset + (best_mv->as_mv.row * (in_what_stride)) +
      best_mv->as_mv.col;
  this_mv.as_mv.row = best_mv->as_mv.row * 8;
  this_mv.as_mv.col = best_mv->as_mv.col * 8;
  if (bestsad == INT_MAX)
    return INT_MAX;
  return
      vfp->vf(what, what_stride, this_offset, in_what_stride,
              (unsigned int *)(&bestsad)) +
      use_mvcost ? mv_err_cost(&this_mv, center_mv, x->nmvjointcost, x->mvcost,
                               x->errorperbit) : 0;
}


int vp9_hex_search(MACROBLOCK *x,
                   int_mv *ref_mv,
                   int search_param,
                   int sad_per_bit,
                   int do_init_search,
                   const vp9_variance_fn_ptr_t *vfp,
                   int use_mvcost,
                   int_mv *center_mv, int_mv *best_mv) {
  // First scale has 8-closest points, the rest have 6 points in hex shape
  // at increasing scales
  static const int hex_num_candidates[MAX_PATTERN_SCALES] = {
    8, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6
  };
  // Note that the largest candidate step at each scale is 2^scale
  static const MV hex_candidates[MAX_PATTERN_SCALES][MAX_PATTERN_CANDIDATES] = {
    {{-1, -1}, {0, -1}, {1, -1}, {1, 0}, {1, 1}, { 0, 1}, { -1, 1}, {-1, 0}},
    {{-1, -2}, {1, -2}, {2, 0}, {1, 2}, { -1, 2}, { -2, 0}},
    {{-2, -4}, {2, -4}, {4, 0}, {2, 4}, { -2, 4}, { -4, 0}},
    {{-4, -8}, {4, -8}, {8, 0}, {4, 8}, { -4, 8}, { -8, 0}},
    {{-8, -16}, {8, -16}, {16, 0}, {8, 16}, { -8, 16}, { -16, 0}},
    {{-16, -32}, {16, -32}, {32, 0}, {16, 32}, { -16, 32}, { -32, 0}},
    {{-32, -64}, {32, -64}, {64, 0}, {32, 64}, { -32, 64}, { -64, 0}},
    {{-64, -128}, {64, -128}, {128, 0}, {64, 128}, { -64, 128}, { -128, 0}},
    {{-128, -256}, {128, -256}, {256, 0}, {128, 256}, { -128, 256}, { -256, 0}},
    {{-256, -512}, {256, -512}, {512, 0}, {256, 512}, { -256, 512}, { -512, 0}},
    {{-512, -1024}, {512, -1024}, {1024, 0}, {512, 1024}, { -512, 1024},
      { -1024, 0}},
  };
  return
      vp9_pattern_search(x, ref_mv, search_param, sad_per_bit,
                         do_init_search, 0, vfp, use_mvcost,
                         center_mv, best_mv,
                         hex_num_candidates, hex_candidates);
}

int vp9_bigdia_search(MACROBLOCK *x,
                      int_mv *ref_mv,
                      int search_param,
                      int sad_per_bit,
                      int do_init_search,
                      const vp9_variance_fn_ptr_t *vfp,
                      int use_mvcost,
                      int_mv *center_mv,
                      int_mv *best_mv) {
  // First scale has 4-closest points, the rest have 8 points in diamond
  // shape at increasing scales
  static const int bigdia_num_candidates[MAX_PATTERN_SCALES] = {
    4, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
  };
  // Note that the largest candidate step at each scale is 2^scale
  static const MV bigdia_candidates[MAX_PATTERN_SCALES]
                                   [MAX_PATTERN_CANDIDATES] = {
    {{0, -1}, {1, 0}, { 0, 1}, {-1, 0}},
    {{-1, -1}, {0, -2}, {1, -1}, {2, 0}, {1, 1}, {0, 2}, {-1, 1}, {-2, 0}},
    {{-2, -2}, {0, -4}, {2, -2}, {4, 0}, {2, 2}, {0, 4}, {-2, 2}, {-4, 0}},
    {{-4, -4}, {0, -8}, {4, -4}, {8, 0}, {4, 4}, {0, 8}, {-4, 4}, {-8, 0}},
    {{-8, -8}, {0, -16}, {8, -8}, {16, 0}, {8, 8}, {0, 16}, {-8, 8}, {-16, 0}},
    {{-16, -16}, {0, -32}, {16, -16}, {32, 0}, {16, 16}, {0, 32},
      {-16, 16}, {-32, 0}},
    {{-32, -32}, {0, -64}, {32, -32}, {64, 0}, {32, 32}, {0, 64},
      {-32, 32}, {-64, 0}},
    {{-64, -64}, {0, -128}, {64, -64}, {128, 0}, {64, 64}, {0, 128},
      {-64, 64}, {-128, 0}},
    {{-128, -128}, {0, -256}, {128, -128}, {256, 0}, {128, 128}, {0, 256},
      {-128, 128}, {-256, 0}},
    {{-256, -256}, {0, -512}, {256, -256}, {512, 0}, {256, 256}, {0, 512},
      {-256, 256}, {-512, 0}},
    {{-512, -512}, {0, -1024}, {512, -512}, {1024, 0}, {512, 512}, {0, 1024},
      {-512, 512}, {-1024, 0}},
  };
  return
      vp9_pattern_search(x, ref_mv, search_param, sad_per_bit,
                         do_init_search, 0, vfp, use_mvcost,
                         center_mv, best_mv,
                         bigdia_num_candidates, bigdia_candidates);
}

int vp9_square_search(MACROBLOCK *x,
                      int_mv *ref_mv,
                      int search_param,
                      int sad_per_bit,
                      int do_init_search,
                      const vp9_variance_fn_ptr_t *vfp,
                      int use_mvcost,
                      int_mv *center_mv,
                      int_mv *best_mv) {
  // All scales have 8 closest points in square shape
  static const int square_num_candidates[MAX_PATTERN_SCALES] = {
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
  };
  // Note that the largest candidate step at each scale is 2^scale
  static const MV square_candidates[MAX_PATTERN_SCALES]
                                   [MAX_PATTERN_CANDIDATES] = {
    {{-1, -1}, {0, -1}, {1, -1}, {1, 0}, {1, 1}, {0, 1}, {-1, 1}, {-1, 0}},
    {{-2, -2}, {0, -2}, {2, -2}, {2, 0}, {2, 2}, {0, 2}, {-2, 2}, {-2, 0}},
    {{-4, -4}, {0, -4}, {4, -4}, {4, 0}, {4, 4}, {0, 4}, {-4, 4}, {-4, 0}},
    {{-8, -8}, {0, -8}, {8, -8}, {8, 0}, {8, 8}, {0, 8}, {-8, 8}, {-8, 0}},
    {{-16, -16}, {0, -16}, {16, -16}, {16, 0}, {16, 16}, {0, 16},
      {-16, 16}, {-16, 0}},
    {{-32, -32}, {0, -32}, {32, -32}, {32, 0}, {32, 32}, {0, 32},
      {-32, 32}, {-32, 0}},
    {{-64, -64}, {0, -64}, {64, -64}, {64, 0}, {64, 64}, {0, 64},
      {-64, 64}, {-64, 0}},
    {{-128, -128}, {0, -128}, {128, -128}, {128, 0}, {128, 128}, {0, 128},
      {-128, 128}, {-128, 0}},
    {{-256, -256}, {0, -256}, {256, -256}, {256, 0}, {256, 256}, {0, 256},
      {-256, 256}, {-256, 0}},
    {{-512, -512}, {0, -512}, {512, -512}, {512, 0}, {512, 512}, {0, 512},
      {-512, 512}, {-512, 0}},
    {{-1024, -1024}, {0, -1024}, {1024, -1024}, {1024, 0}, {1024, 1024},
      {0, 1024}, {-1024, 1024}, {-1024, 0}},
  };
  return
      vp9_pattern_search(x, ref_mv, search_param, sad_per_bit,
                         do_init_search, 0, vfp, use_mvcost,
                         center_mv, best_mv,
                         square_num_candidates, square_candidates);
};

#undef CHECK_BOUNDS
#undef CHECK_POINT
#undef CHECK_BETTER

int vp9_diamond_search_sad_c(MACROBLOCK *x,
                             int_mv *ref_mv, int_mv *best_mv,
                             int search_param, int sad_per_bit, int *num00,
                             vp9_variance_fn_ptr_t *fn_ptr, int *mvjcost,
                             int *mvcost[2], int_mv *center_mv) {
  int i, j, step;

  const MACROBLOCKD* const xd = &x->e_mbd;
  uint8_t *what = x->plane[0].src.buf;
  int what_stride = x->plane[0].src.stride;
  uint8_t *in_what;
  int in_what_stride = xd->plane[0].pre[0].stride;
  uint8_t *best_address;

  int tot_steps;
  int_mv this_mv;

  int bestsad = INT_MAX;
  int best_site = 0;
  int last_site = 0;

  int ref_row, ref_col;
  int this_row_offset, this_col_offset;
  search_site *ss;

  uint8_t *check_here;
  int thissad;
  int_mv fcenter_mv;

  int *mvjsadcost = x->nmvjointsadcost;
  int *mvsadcost[2] = {x->nmvsadcost[0], x->nmvsadcost[1]};

  fcenter_mv.as_mv.row = center_mv->as_mv.row >> 3;
  fcenter_mv.as_mv.col = center_mv->as_mv.col >> 3;

  clamp_mv(&ref_mv->as_mv,
           x->mv_col_min, x->mv_col_max, x->mv_row_min, x->mv_row_max);
  ref_row = ref_mv->as_mv.row;
  ref_col = ref_mv->as_mv.col;
  *num00 = 0;
  best_mv->as_mv.row = ref_row;
  best_mv->as_mv.col = ref_col;

  // Work out the start point for the search
  in_what = (uint8_t *)(xd->plane[0].pre[0].buf +
                        (ref_row * (xd->plane[0].pre[0].stride)) + ref_col);
  best_address = in_what;

  // Check the starting position
  bestsad = fn_ptr->sdf(what, what_stride, in_what,
                        in_what_stride, 0x7fffffff)
            + mvsad_err_cost(best_mv, &fcenter_mv, mvjsadcost, mvsadcost,
                             sad_per_bit);

  // search_param determines the length of the initial step and hence the number of iterations
  // 0 = initial step (MAX_FIRST_STEP) pel : 1 = (MAX_FIRST_STEP/2) pel, 2 = (MAX_FIRST_STEP/4) pel... etc.
  ss = &x->ss[search_param * x->searches_per_step];
  tot_steps = (x->ss_count / x->searches_per_step) - search_param;

  i = 1;

  for (step = 0; step < tot_steps; step++) {
    for (j = 0; j < x->searches_per_step; j++) {
      // Trap illegal vectors
      this_row_offset = best_mv->as_mv.row + ss[i].mv.row;
      this_col_offset = best_mv->as_mv.col + ss[i].mv.col;

      if ((this_col_offset > x->mv_col_min) &&
          (this_col_offset < x->mv_col_max) &&
          (this_row_offset > x->mv_row_min) &&
          (this_row_offset < x->mv_row_max)) {
        check_here = ss[i].offset + best_address;
        thissad = fn_ptr->sdf(what, what_stride, check_here, in_what_stride,
                              bestsad);

        if (thissad < bestsad) {
          this_mv.as_mv.row = this_row_offset;
          this_mv.as_mv.col = this_col_offset;
          thissad += mvsad_err_cost(&this_mv, &fcenter_mv,
                                    mvjsadcost, mvsadcost, sad_per_bit);

          if (thissad < bestsad) {
            bestsad = thissad;
            best_site = i;
          }
        }
      }

      i++;
    }

    if (best_site != last_site) {
      best_mv->as_mv.row += ss[best_site].mv.row;
      best_mv->as_mv.col += ss[best_site].mv.col;
      best_address += ss[best_site].offset;
      last_site = best_site;
#if defined(NEW_DIAMOND_SEARCH)
      while (1) {
        this_row_offset = best_mv->as_mv.row + ss[best_site].mv.row;
        this_col_offset = best_mv->as_mv.col + ss[best_site].mv.col;
        if ((this_col_offset > x->mv_col_min) &&
            (this_col_offset < x->mv_col_max) &&
            (this_row_offset > x->mv_row_min) &&
            (this_row_offset < x->mv_row_max)) {
          check_here = ss[best_site].offset + best_address;
          thissad = fn_ptr->sdf(what, what_stride, check_here, in_what_stride,
                                bestsad);
          if (thissad < bestsad) {
            this_mv.as_mv.row = this_row_offset;
            this_mv.as_mv.col = this_col_offset;
            thissad += mvsad_err_cost(&this_mv, &fcenter_mv,
                                      mvjsadcost, mvsadcost, sad_per_bit);
            if (thissad < bestsad) {
              bestsad = thissad;
              best_mv->as_mv.row += ss[best_site].mv.row;
              best_mv->as_mv.col += ss[best_site].mv.col;
              best_address += ss[best_site].offset;
              continue;
            }
          }
        }
        break;
      };
#endif
    } else if (best_address == in_what)
      (*num00)++;
  }

  this_mv.as_mv.row = best_mv->as_mv.row * 8;
  this_mv.as_mv.col = best_mv->as_mv.col * 8;

  if (bestsad == INT_MAX)
    return INT_MAX;

  return fn_ptr->vf(what, what_stride, best_address, in_what_stride,
         (unsigned int *)(&thissad)) + mv_err_cost(&this_mv, center_mv, mvjcost,
                                                   mvcost, x->errorperbit);
}

int vp9_diamond_search_sadx4(MACROBLOCK *x,
                             int_mv *ref_mv, int_mv *best_mv, int search_param,
                             int sad_per_bit, int *num00,
                             vp9_variance_fn_ptr_t *fn_ptr,
                             int *mvjcost, int *mvcost[2], int_mv *center_mv) {
  int i, j, step;

  const MACROBLOCKD* const xd = &x->e_mbd;
  uint8_t *what = x->plane[0].src.buf;
  int what_stride = x->plane[0].src.stride;
  uint8_t *in_what;
  int in_what_stride = xd->plane[0].pre[0].stride;
  uint8_t *best_address;

  int tot_steps;
  int_mv this_mv;

  unsigned int bestsad = INT_MAX;
  int best_site = 0;
  int last_site = 0;

  int ref_row;
  int ref_col;
  int this_row_offset;
  int this_col_offset;
  search_site *ss;

  uint8_t *check_here;
  unsigned int thissad;
  int_mv fcenter_mv;

  int *mvjsadcost = x->nmvjointsadcost;
  int *mvsadcost[2] = {x->nmvsadcost[0], x->nmvsadcost[1]};

  fcenter_mv.as_mv.row = center_mv->as_mv.row >> 3;
  fcenter_mv.as_mv.col = center_mv->as_mv.col >> 3;

  clamp_mv(&ref_mv->as_mv,
           x->mv_col_min, x->mv_col_max, x->mv_row_min, x->mv_row_max);
  ref_row = ref_mv->as_mv.row;
  ref_col = ref_mv->as_mv.col;
  *num00 = 0;
  best_mv->as_mv.row = ref_row;
  best_mv->as_mv.col = ref_col;

  // Work out the start point for the search