/*

 *  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 "./vp8_rtcd.h"

#include "./vpx_dsp_rtcd.h"

#include "onyx_int.h"

#include "mcomp.h"

#include "vpx_mem/vpx_mem.h"

#include "vpx_config.h"

#include <stdio.h>

#include <limits.h>

#include <math.h>

#include "vp8/common/findnearmv.h"

#include "vp8/common/common.h"

#include "vpx_dsp/vpx_dsp_common.h"

int vp8_mv_bit_cost(int_mv *mv, int_mv *ref, int *mvcost[2], int Weight) {

  /* MV costing is based on the distribution of vectors in the previous

   * frame and as such will tend to over state the cost of vectors. In

   * addition coding a new vector can have a knock on effect on the cost

   * of subsequent vectors and the quality of prediction from NEAR and

   * NEAREST for subsequent blocks. The "Weight" parameter allows, to a

   * limited extent, for some account to be taken of these factors.

   */

  const int mv_idx_row =

      clamp((mv->as_mv.row - ref->as_mv.row) >> 1, 0, MVvals);

  const int mv_idx_col =

      clamp((mv->as_mv.col - ref->as_mv.col) >> 1, 0, MVvals);

  return ((mvcost[0][mv_idx_row] + mvcost[1][mv_idx_col]) * Weight) >> 7;

}

static int mv_err_cost(int_mv *mv, int_mv *ref, int *mvcost[2],

                       int error_per_bit) {

  /* Ignore mv costing if mvcost is NULL */

  if (mvcost) {

    const int mv_idx_row =

        clamp((mv->as_mv.row - ref->as_mv.row) >> 1, 0, MVvals);

    const int mv_idx_col =

        clamp((mv->as_mv.col - ref->as_mv.col) >> 1, 0, MVvals);

    return ((mvcost[0][mv_idx_row] + mvcost[1][mv_idx_col]) * error_per_bit +

            128) >>

           8;

  }

  return 0;

}

static int mvsad_err_cost(int_mv *mv, int_mv *ref, int *mvsadcost[2],

                          int error_per_bit) {

  /* Calculate sad error cost on full pixel basis. */

  /* Ignore mv costing if mvsadcost is NULL */

  if (mvsadcost) {

    return ((mvsadcost[0][(mv->as_mv.row - ref->as_mv.row)] +

             mvsadcost[1][(mv->as_mv.col - ref->as_mv.col)]) *

                error_per_bit +

            128) >>

           8;

  }

  return 0;

}

void vp8_init_dsmotion_compensation(MACROBLOCK *x, int stride) {

  int Len;

  int search_site_count = 0;

  /* Generate offsets for 4 search sites per step. */

  Len = MAX_FIRST_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++;

  while (Len > 0) {

    /* 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++;

    /* Contract. */

    Len /= 2;

  }

  x->ss_count = search_site_count;

  x->searches_per_step = 4;

}

void vp8_init3smotion_compensation(MACROBLOCK *x, int stride) {

  int Len;

  int search_site_count = 0;

  /* Generate offsets for 8 search sites per step. */

  Len = MAX_FIRST_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++;

  while (Len > 0) {

    /* 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++;

    /* Compute offsets for search sites. */

    x->ss[search_site_count].mv.col = -Len;

    x->ss[search_site_count].mv.row = -Len;

    x->ss[search_site_count].offset = -Len * stride - Len;

    search_site_count++;

    /* Compute offsets for search sites. */

    x->ss[search_site_count].mv.col = Len;

    x->ss[search_site_count].mv.row = -Len;

    x->ss[search_site_count].offset = -Len * stride + Len;

    search_site_count++;

    /* Compute offsets for search sites. */

    x->ss[search_site_count].mv.col = -Len;

    x->ss[search_site_count].mv.row = Len;

    x->ss[search_site_count].offset = Len * stride - Len;

    search_site_count++;

    /* Compute offsets for search sites. */

    x->ss[search_site_count].mv.col = Len;

    x->ss[search_site_count].mv.row = Len;

    x->ss[search_site_count].offset = Len * stride + Len;

    search_site_count++;

    /* Contract. */

    Len /= 2;

  }

  x->ss_count = search_site_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 ? ((mvcost[0][(r) - rr] + mvcost[1][(c) - rc]) * error_per_bit + \

             128) >>                                                       \

                8                                                          \

          : 0)

/* pointer to predictor base of a motionvector */

#define PRE(r, c) (y + (((r) >> 2) * y_stride + ((c) >> 2) - (offset)))

/* convert motion vector component to offset for svf calc */

#define SP(x) (((x) & 3) << 1)

/* returns subpixel variance error function. */

#define DIST(r, c) \

  vfp->svf(PRE(r, c), y_stride, SP(c), SP(r), z, b->src_stride, &sse)

#define IFMVCV(r, c, s, e) \

  if (c >= minc && c <= maxc && r >= minr && r <= maxr) s else e;

/* returns distortion + motion vector cost */

#define ERR(r, c) (MVC(r, c) + DIST(r, c))

/* checks if (r,c) has better score than previous best */

#define CHECK_BETTER(v, r, c)                          \

  do {                                                 \

    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 = UINT_MAX;)                                 \

  } while (0)

int vp8_find_best_sub_pixel_step_iteratively(MACROBLOCK *x, BLOCK *b, BLOCKD *d,

                                             int_mv *bestmv, int_mv *ref_mv,

                                             int error_per_bit,

                                             const vp8_variance_fn_ptr_t *vfp,

                                             int *mvcost[2], int *distortion,

                                             unsigned int *sse1) {

  unsigned char *z = (*(b->base_src) + b->src);

  int rr = ref_mv->as_mv.row >> 1, rc = ref_mv->as_mv.col >> 1;

  int br = bestmv->as_mv.row * 4, bc = bestmv->as_mv.col * 4;

  int tr = br, tc = bc;

  unsigned int besterr;

  unsigned int left, right, up, down, diag;

  unsigned int sse;

  unsigned int whichdir;

  unsigned int halfiters = 4;

  unsigned int quarteriters = 4;

  int thismse;

  int minc = VPXMAX(x->mv_col_min * 4,

                    (ref_mv->as_mv.col >> 1) - ((1 << mvlong_width) - 1));

  int maxc = VPXMIN(x->mv_col_max * 4,

                    (ref_mv->as_mv.col >> 1) + ((1 << mvlong_width) - 1));

  int minr = VPXMAX(x->mv_row_min * 4,

                    (ref_mv->as_mv.row >> 1) - ((1 << mvlong_width) - 1));

  int maxr = VPXMIN(x->mv_row_max * 4,

                    (ref_mv->as_mv.row >> 1) + ((1 << mvlong_width) - 1));

  int y_stride;

  int offset;

  int pre_stride = x->e_mbd.pre.y_stride;

  unsigned char *base_pre = x->e_mbd.pre.y_buffer;

#if VPX_ARCH_X86 || VPX_ARCH_X86_64

  MACROBLOCKD *xd = &x->e_mbd;

  unsigned char *y_0 = base_pre + d->offset + (bestmv->as_mv.row) * pre_stride +

                       bestmv->as_mv.col;

  unsigned char *y;

  int buf_r1, buf_r2, buf_c1;

  /* Clamping to avoid out-of-range data access */

  buf_r1 = ((bestmv->as_mv.row - 3) < x->mv_row_min)

               ? (bestmv->as_mv.row - x->mv_row_min)

               : 3;

  buf_r2 = ((bestmv->as_mv.row + 3) > x->mv_row_max)

               ? (x->mv_row_max - bestmv->as_mv.row)

               : 3;

  buf_c1 = ((bestmv->as_mv.col - 3) < x->mv_col_min)

               ? (bestmv->as_mv.col - x->mv_col_min)

               : 3;

  y_stride = 32;

  /* Copy to intermediate buffer before searching. */

  vfp->copymem(y_0 - buf_c1 - pre_stride * buf_r1, pre_stride, xd->y_buf,

               y_stride, 16 + buf_r1 + buf_r2);

  y = xd->y_buf + y_stride * buf_r1 + buf_c1;

#else

  unsigned char *y = base_pre + d->offset + (bestmv->as_mv.row) * pre_stride +

                     bestmv->as_mv.col;

  y_stride = pre_stride;

#endif

  offset = (bestmv->as_mv.row) * y_stride + bestmv->as_mv.col;

  /* central mv */

  bestmv->as_mv.row = clamp(bestmv->as_mv.row * 8, SHRT_MIN, SHRT_MAX);

  bestmv->as_mv.col = clamp(bestmv->as_mv.col * 8, SHRT_MIN, SHRT_MAX);

  /* calculate central point error */

  besterr = vfp->vf(y, y_stride, z, b->src_stride, sse1);

  *distortion = besterr;

  besterr += mv_err_cost(bestmv, ref_mv, 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 */

    CHECK_BETTER(left, tr, tc - 2);

    CHECK_BETTER(right, tr, tc + 2);

    CHECK_BETTER(up, tr - 2, tc);

    CHECK_BETTER(down, tr + 2, tc);

    whichdir = (left < right ? 0 : 1) + (up < down ? 0 : 2);

    switch (whichdir) {

      case 0: CHECK_BETTER(diag, tr - 2, tc - 2); break;

      case 1: CHECK_BETTER(diag, tr - 2, tc + 2); break;

      case 2: CHECK_BETTER(diag, tr + 2, tc - 2); break;

      case 3: CHECK_BETTER(diag, tr + 2, tc + 2); break;

    }

    /* 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 */

  while (--quarteriters) {

    CHECK_BETTER(left, tr, tc - 1);

    CHECK_BETTER(right, tr, tc + 1);

    CHECK_BETTER(up, tr - 1, tc);

    CHECK_BETTER(down, tr + 1, tc);

    whichdir = (left < right ? 0 : 1) + (up < down ? 0 : 2);

    switch (whichdir) {

      case 0: CHECK_BETTER(diag, tr - 1, tc - 1); break;

      case 1: CHECK_BETTER(diag, tr - 1, tc + 1); break;

      case 2: CHECK_BETTER(diag, tr + 1, tc - 1); break;

      case 3: CHECK_BETTER(diag, tr + 1, tc + 1); break;

    }

    /* no reason to check the same one again. */

    if (tr == br && tc == bc) break;

    tr = br;

    tc = bc;

  }

  bestmv->as_mv.row = clamp(br * 2, SHRT_MIN, SHRT_MAX);

  bestmv->as_mv.col = clamp(bc * 2, SHRT_MIN, SHRT_MAX);

  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 SP

#undef DIST

#undef IFMVCV

#undef ERR

#undef CHECK_BETTER

int vp8_find_best_sub_pixel_step(MACROBLOCK *x, BLOCK *b, BLOCKD *d,

                                 int_mv *bestmv, int_mv *ref_mv,

                                 int error_per_bit,

                                 const vp8_variance_fn_ptr_t *vfp,

                                 int *mvcost[2], int *distortion,

                                 unsigned int *sse1) {

  int bestmse = INT_MAX;

  int_mv startmv;

  int_mv this_mv;

  unsigned char *z = (*(b->base_src) + b->src);

  int left, right, up, down, diag;

  unsigned int sse;

  int whichdir;

  int thismse;

  int y_stride;

  int pre_stride = x->e_mbd.pre.y_stride;

  unsigned char *base_pre = x->e_mbd.pre.y_buffer;

#if VPX_ARCH_X86 || VPX_ARCH_X86_64

  MACROBLOCKD *xd = &x->e_mbd;

  unsigned char *y_0 = base_pre + d->offset + (bestmv->as_mv.row) * pre_stride +

                       bestmv->as_mv.col;

  unsigned char *y;

  y_stride = 32;

  /* Copy 18 rows x 32 cols area to intermediate buffer before searching. */

  vfp->copymem(y_0 - 1 - pre_stride, pre_stride, xd->y_buf, y_stride, 18);

  y = xd->y_buf + y_stride + 1;

#else

  unsigned char *y = base_pre + d->offset + (bestmv->as_mv.row) * pre_stride +

                     bestmv->as_mv.col;

  y_stride = pre_stride;

#endif

  /* central mv */

  bestmv->as_mv.row = clamp(bestmv->as_mv.row * 8, SHRT_MIN, SHRT_MAX);

  bestmv->as_mv.col = clamp(bestmv->as_mv.col * 8, SHRT_MIN, SHRT_MAX);

  startmv = *bestmv;

  /* calculate central point error */

  bestmse = vfp->vf(y, y_stride, z, b->src_stride, sse1);

  *distortion = bestmse;

  bestmse += mv_err_cost(bestmv, ref_mv, mvcost, error_per_bit);

  /* go left then right and check error */

  this_mv.as_mv.row = startmv.as_mv.row;

  this_mv.as_mv.col = ((startmv.as_mv.col - 8) | 4);

  /* "halfpix" horizontal variance */

  thismse = vfp->svf(y - 1, y_stride, 4, 0, z, b->src_stride, &sse);

  left = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (left < bestmse) {

    *bestmv = this_mv;

    bestmse = left;

    *distortion = thismse;

    *sse1 = sse;

  }

  this_mv.as_mv.col += 8;

  /* "halfpix" horizontal variance */

  thismse = vfp->svf(y, y_stride, 4, 0, z, b->src_stride, &sse);

  right = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (right < bestmse) {

    *bestmv = this_mv;

    bestmse = right;

    *distortion = thismse;

    *sse1 = sse;

  }

  /* go up then down and check error */

  this_mv.as_mv.col = startmv.as_mv.col;

  this_mv.as_mv.row = ((startmv.as_mv.row - 8) | 4);

  /* "halfpix" vertical variance */

  thismse = vfp->svf(y - y_stride, y_stride, 0, 4, z, b->src_stride, &sse);

  up = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (up < bestmse) {

    *bestmv = this_mv;

    bestmse = up;

    *distortion = thismse;

    *sse1 = sse;

  }

  this_mv.as_mv.row += 8;

  /* "halfpix" vertical variance */

  thismse = vfp->svf(y, y_stride, 0, 4, z, b->src_stride, &sse);

  down = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (down < bestmse) {

    *bestmv = this_mv;

    bestmse = down;

    *distortion = thismse;

    *sse1 = sse;

  }

  /* now check 1 more diagonal */

  whichdir = (left < right ? 0 : 1) + (up < down ? 0 : 2);

  this_mv = startmv;

  switch (whichdir) {

    case 0:

      this_mv.as_mv.col = (this_mv.as_mv.col - 8) | 4;

      this_mv.as_mv.row = (this_mv.as_mv.row - 8) | 4;

      /* "halfpix" horizontal/vertical variance */

      thismse =

          vfp->svf(y - 1 - y_stride, y_stride, 4, 4, z, b->src_stride, &sse);

      break;

    case 1:

      this_mv.as_mv.col += 4;

      this_mv.as_mv.row = (this_mv.as_mv.row - 8) | 4;

      /* "halfpix" horizontal/vertical variance */

      thismse = vfp->svf(y - y_stride, y_stride, 4, 4, z, b->src_stride, &sse);

      break;

    case 2:

      this_mv.as_mv.col = (this_mv.as_mv.col - 8) | 4;

      this_mv.as_mv.row += 4;

      /* "halfpix" horizontal/vertical variance */

      thismse = vfp->svf(y - 1, y_stride, 4, 4, z, b->src_stride, &sse);

      break;

    case 3:

    default:

      this_mv.as_mv.col += 4;

      this_mv.as_mv.row += 4;

      /* "halfpix" horizontal/vertical variance */

      thismse = vfp->svf(y, y_stride, 4, 4, z, b->src_stride, &sse);

      break;

  }

  diag = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (diag < bestmse) {

    *bestmv = this_mv;

    bestmse = diag;

    *distortion = thismse;

    *sse1 = sse;

  }

  /* time to check quarter pels. */

  if (bestmv->as_mv.row < startmv.as_mv.row) y -= y_stride;

  if (bestmv->as_mv.col < startmv.as_mv.col) y--;

  startmv = *bestmv;

  /* go left then right and check error */

  this_mv.as_mv.row = startmv.as_mv.row;

  if (startmv.as_mv.col & 7) {

    this_mv.as_mv.col = startmv.as_mv.col - 2;

    thismse = vfp->svf(y, y_stride, this_mv.as_mv.col & 7,

                       this_mv.as_mv.row & 7, z, b->src_stride, &sse);

  } else {

    this_mv.as_mv.col = (startmv.as_mv.col - 8) | 6;

    thismse = vfp->svf(y - 1, y_stride, 6, this_mv.as_mv.row & 7, z,

                       b->src_stride, &sse);

  }

  left = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (left < bestmse) {

    *bestmv = this_mv;

    bestmse = left;

    *distortion = thismse;

    *sse1 = sse;

  }

  this_mv.as_mv.col += 4;

  thismse = vfp->svf(y, y_stride, this_mv.as_mv.col & 7, this_mv.as_mv.row & 7,

                     z, b->src_stride, &sse);

  right = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (right < bestmse) {

    *bestmv = this_mv;

    bestmse = right;

    *distortion = thismse;

    *sse1 = sse;

  }

  /* go up then down and check error */

  this_mv.as_mv.col = startmv.as_mv.col;

  if (startmv.as_mv.row & 7) {

    this_mv.as_mv.row = startmv.as_mv.row - 2;

    thismse = vfp->svf(y, y_stride, this_mv.as_mv.col & 7,

                       this_mv.as_mv.row & 7, z, b->src_stride, &sse);

  } else {

    this_mv.as_mv.row = (startmv.as_mv.row - 8) | 6;

    thismse = vfp->svf(y - y_stride, y_stride, this_mv.as_mv.col & 7, 6, z,

                       b->src_stride, &sse);

  }

  up = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (up < bestmse) {

    *bestmv = this_mv;

    bestmse = up;

    *distortion = thismse;

    *sse1 = sse;

  }

  this_mv.as_mv.row += 4;

  thismse = vfp->svf(y, y_stride, this_mv.as_mv.col & 7, this_mv.as_mv.row & 7,

                     z, b->src_stride, &sse);

  down = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (down < bestmse) {

    *bestmv = this_mv;

    bestmse = down;

    *distortion = thismse;

    *sse1 = sse;

  }

  /* now check 1 more diagonal */

  whichdir = (left < right ? 0 : 1) + (up < down ? 0 : 2);

  this_mv = startmv;

  switch (whichdir) {

    case 0:

      if (startmv.as_mv.row & 7) {

        this_mv.as_mv.row -= 2;

        if (startmv.as_mv.col & 7) {

          this_mv.as_mv.col -= 2;

          thismse = vfp->svf(y, y_stride, this_mv.as_mv.col & 7,

                             this_mv.as_mv.row & 7, z, b->src_stride, &sse);

        } else {

          this_mv.as_mv.col = (startmv.as_mv.col - 8) | 6;

          thismse = vfp->svf(y - 1, y_stride, 6, this_mv.as_mv.row & 7, z,

                             b->src_stride, &sse);

        }

      } else {

        this_mv.as_mv.row = (startmv.as_mv.row - 8) | 6;

        if (startmv.as_mv.col & 7) {

          this_mv.as_mv.col -= 2;

          thismse = vfp->svf(y - y_stride, y_stride, this_mv.as_mv.col & 7, 6,

                             z, b->src_stride, &sse);

        } else {

          this_mv.as_mv.col = (startmv.as_mv.col - 8) | 6;

          thismse = vfp->svf(y - y_stride - 1, y_stride, 6, 6, z, b->src_stride,

                             &sse);

        }

      }

      break;

    case 1:

      this_mv.as_mv.col += 2;

      if (startmv.as_mv.row & 7) {

        this_mv.as_mv.row -= 2;

        thismse = vfp->svf(y, y_stride, this_mv.as_mv.col & 7,

                           this_mv.as_mv.row & 7, z, b->src_stride, &sse);

      } else {

        this_mv.as_mv.row = (startmv.as_mv.row - 8) | 6;

        thismse = vfp->svf(y - y_stride, y_stride, this_mv.as_mv.col & 7, 6, z,

                           b->src_stride, &sse);

      }

      break;

    case 2:

      this_mv.as_mv.row += 2;

      if (startmv.as_mv.col & 7) {

        this_mv.as_mv.col -= 2;

        thismse = vfp->svf(y, y_stride, this_mv.as_mv.col & 7,

                           this_mv.as_mv.row & 7, z, b->src_stride, &sse);

      } else {

        this_mv.as_mv.col = (startmv.as_mv.col - 8) | 6;

        thismse = vfp->svf(y - 1, y_stride, 6, this_mv.as_mv.row & 7, z,

                           b->src_stride, &sse);

      }

      break;

    case 3:

      this_mv.as_mv.col += 2;

      this_mv.as_mv.row += 2;

      thismse = vfp->svf(y, y_stride, this_mv.as_mv.col & 7,

                         this_mv.as_mv.row & 7, z, b->src_stride, &sse);

      break;

  }

  diag = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (diag < bestmse) {

    *bestmv = this_mv;

    bestmse = diag;

    *distortion = thismse;

    *sse1 = sse;

  }

  return bestmse;

}

int vp8_find_best_half_pixel_step(MACROBLOCK *x, BLOCK *b, BLOCKD *d,

                                  int_mv *bestmv, int_mv *ref_mv,

                                  int error_per_bit,

                                  const vp8_variance_fn_ptr_t *vfp,

                                  int *mvcost[2], int *distortion,

                                  unsigned int *sse1) {

  int bestmse = INT_MAX;

  int_mv startmv;

  int_mv this_mv;

  unsigned char *z = (*(b->base_src) + b->src);

  int left, right, up, down, diag;

  unsigned int sse;

  int whichdir;

  int thismse;

  int y_stride;

  int pre_stride = x->e_mbd.pre.y_stride;

  unsigned char *base_pre = x->e_mbd.pre.y_buffer;

#if VPX_ARCH_X86 || VPX_ARCH_X86_64

  MACROBLOCKD *xd = &x->e_mbd;

  unsigned char *y_0 = base_pre + d->offset + (bestmv->as_mv.row) * pre_stride +

                       bestmv->as_mv.col;

  unsigned char *y;

  y_stride = 32;

  /* Copy 18 rows x 32 cols area to intermediate buffer before searching. */

  vfp->copymem(y_0 - 1 - pre_stride, pre_stride, xd->y_buf, y_stride, 18);

  y = xd->y_buf + y_stride + 1;

#else

  unsigned char *y = base_pre + d->offset + (bestmv->as_mv.row) * pre_stride +

                     bestmv->as_mv.col;

  y_stride = pre_stride;

#endif

  /* central mv */

  bestmv->as_mv.row = clamp(bestmv->as_mv.row * 8, SHRT_MIN, SHRT_MAX);

  bestmv->as_mv.col = clamp(bestmv->as_mv.col * 8, SHRT_MIN, SHRT_MAX);

  startmv = *bestmv;

  /* calculate central point error */

  bestmse = vfp->vf(y, y_stride, z, b->src_stride, sse1);

  *distortion = bestmse;

  bestmse += mv_err_cost(bestmv, ref_mv, mvcost, error_per_bit);

  /* go left then right and check error */

  this_mv.as_mv.row = startmv.as_mv.row;

  this_mv.as_mv.col = ((startmv.as_mv.col - 8) | 4);

  /* "halfpix" horizontal variance */

  thismse = vfp->svf(y - 1, y_stride, 4, 0, z, b->src_stride, &sse);

  left = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (left < bestmse) {

    *bestmv = this_mv;

    bestmse = left;

    *distortion = thismse;

    *sse1 = sse;

  }

  this_mv.as_mv.col += 8;

  /* "halfpix" horizontal variance */

  thismse = vfp->svf(y, y_stride, 4, 0, z, b->src_stride, &sse);

  right = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (right < bestmse) {

    *bestmv = this_mv;

    bestmse = right;

    *distortion = thismse;

    *sse1 = sse;

  }

  /* go up then down and check error */

  this_mv.as_mv.col = startmv.as_mv.col;

  this_mv.as_mv.row = ((startmv.as_mv.row - 8) | 4);

  /* "halfpix" vertical variance */

  thismse = vfp->svf(y - y_stride, y_stride, 0, 4, z, b->src_stride, &sse);

  up = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (up < bestmse) {

    *bestmv = this_mv;

    bestmse = up;

    *distortion = thismse;

    *sse1 = sse;

  }

  this_mv.as_mv.row += 8;

  /* "halfpix" vertical variance */

  thismse = vfp->svf(y, y_stride, 0, 4, z, b->src_stride, &sse);

  down = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (down < bestmse) {

    *bestmv = this_mv;

    bestmse = down;

    *distortion = thismse;

    *sse1 = sse;

  }

  /* now check 1 more diagonal - */

  whichdir = (left < right ? 0 : 1) + (up < down ? 0 : 2);

  this_mv = startmv;

  switch (whichdir) {

    case 0:

      this_mv.as_mv.col = (this_mv.as_mv.col - 8) | 4;

      this_mv.as_mv.row = (this_mv.as_mv.row - 8) | 4;

      /* "halfpix" horizontal/vertical variance */

      thismse =

          vfp->svf(y - 1 - y_stride, y_stride, 4, 4, z, b->src_stride, &sse);

      break;

    case 1:

      this_mv.as_mv.col += 4;

      this_mv.as_mv.row = (this_mv.as_mv.row - 8) | 4;

      /* "halfpix" horizontal/vertical variance */

      thismse = vfp->svf(y - y_stride, y_stride, 4, 4, z, b->src_stride, &sse);

      break;

    case 2:

      this_mv.as_mv.col = (this_mv.as_mv.col - 8) | 4;

      this_mv.as_mv.row += 4;

      /* "halfpix" horizontal/vertical variance */

      thismse = vfp->svf(y - 1, y_stride, 4, 4, z, b->src_stride, &sse);

      break;

    case 3:

    default:

      this_mv.as_mv.col += 4;

      this_mv.as_mv.row += 4;

      /* "halfpix" horizontal/vertical variance */

      thismse = vfp->svf(y, y_stride, 4, 4, z, b->src_stride, &sse);

      break;

  }

  diag = thismse + mv_err_cost(&this_mv, ref_mv, mvcost, error_per_bit);

  if (diag < bestmse) {

    *bestmv = this_mv;

    bestmse = diag;

    *distortion = thismse;

    *sse1 = sse;

  }

  return bestmse;

}

#define CHECK_BOUNDS(range)                    \

  do {                                         \

    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); \

  } while (0)

#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                                                     \

  do {                                                                   \

    if (thissad < bestsad) {                                             \

      thissad +=                                                         \

          mvsad_err_cost(&this_mv, &fcenter_mv, mvsadcost, sad_per_bit); \

      if (thissad < bestsad) {                                           \

        bestsad = thissad;                                               \

        best_site = i;                                                   \

      }                                                                  \

    }                                                                    \

  } while (0)

static const MV next_chkpts[6][3] = {

  { { -2, 0 }, { -1, -2 }, { 1, -2 } }, { { -1, -2 }, { 1, -2 }, { 2, 0 } },

  { { 1, -2 }, { 2, 0 }, { 1, 2 } },    { { 2, 0 }, { 1, 2 }, { -1, 2 } },

  { { 1, 2 }, { -1, 2 }, { -2, 0 } },   { { -1, 2 }, { -2, 0 }, { -1, -2 } }

};

int vp8_hex_search(MACROBLOCK *x, BLOCK *b, BLOCKD *d, int_mv *ref_mv,

                   int_mv *best_mv, int search_param, int sad_per_bit,

                   const vp8_variance_fn_ptr_t *vfp, int *mvsadcost[2],

                   int_mv *center_mv) {

  MV hex[6] = {

    { -1, -2 }, { 1, -2 }, { 2, 0 }, { 1, 2 }, { -1, 2 }, { -2, 0 }

  };

  MV neighbors[4] = { { 0, -1 }, { -1, 0 }, { 1, 0 }, { 0, 1 } };

  int i, j;

  unsigned char *what = (*(b->base_src) + b->src);

  int what_stride = b->src_stride;

  int pre_stride = x->e_mbd.pre.y_stride;

  unsigned char *base_pre = x->e_mbd.pre.y_buffer;

  int in_what_stride = pre_stride;

  int br, bc;

  int_mv this_mv;

  unsigned int bestsad;

  unsigned int thissad;

  unsigned char *base_offset;

  unsigned char *this_offset;

  int k = -1;

  int all_in;

  int best_site = -1;

  int hex_range = 127;

  int dia_range = 8;

  int_mv fcenter_mv;

  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 */

  vp8_clamp_mv(ref_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 = (unsigned char *)(base_pre + d->offset);

  this_offset = base_offset + (br * (pre_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) +

            mvsad_err_cost(&this_mv, &fcenter_mv, mvsadcost, sad_per_bit);

#if CONFIG_MULTI_RES_ENCODING

  /* Lower search range based on prediction info */

  if (search_param >= 6)

    goto cal_neighbors;

  else if (search_param >= 5)

    hex_range = 4;

  else if (search_param >= 4)

    hex_range = 6;

  else if (search_param >= 3)

    hex_range = 15;

  else if (search_param >= 2)

    hex_range = 31;

  else if (search_param >= 1)

    hex_range = 63;

  dia_range = 8;

#else

  (void)search_param;

#endif

  /* hex search */

  CHECK_BOUNDS(2);

  if (all_in) {

    for (i = 0; i < 6; ++i) {

      this_mv.as_mv.row = br + hex[i].row;

      this_mv.as_mv.col = bc + hex[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);

      CHECK_BETTER;

    }

  } else {

    for (i = 0; i < 6; ++i) {

      this_mv.as_mv.row = br + hex[i].row;

      this_mv.as_mv.col = bc + hex[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);

      CHECK_BETTER;

    }

  }

  if (best_site == -1) {

    goto cal_neighbors;

  } else {

    br += hex[best_site].row;

    bc += hex[best_site].col;

    k = best_site;

  }

  for (j = 1; j < hex_range; ++j) {

    best_site = -1;

    CHECK_BOUNDS(2);

    if (all_in) {

      for (i = 0; i < 3; ++i) {

        this_mv.as_mv.row = br + next_chkpts[k][i].row;

        this_mv.as_mv.col = bc + next_chkpts[k][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);

        CHECK_BETTER;

      }

    } else {

      for (i = 0; i < 3; ++i) {

        this_mv.as_mv.row = br + next_chkpts[k][i].row;

        this_mv.as_mv.col = bc + next_chkpts[k][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);

        CHECK_BETTER;

      }

    }

    if (best_site == -1) {

      break;

    } else {

      br += next_chkpts[k][best_site].row;

      bc += next_chkpts[k][best_site].col;

      k += 5 + best_site;

      if (k >= 12) {

        k -= 12;

      } else if (k >= 6) {

        k -= 6;

      }

    }

  }

/* check 4 1-away neighbors */

cal_neighbors:

  for (j = 0; j < dia_range; ++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);

        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);

        CHECK_BETTER;

      }

    }

    if (best_site == -1) {

      break;

    } else {

      br += neighbors[best_site].row;

      bc += neighbors[best_site].col;