/*

 *  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 "findnearmv.h"

const unsigned char vp8_mbsplit_offset[4][16] = {

  { 0, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },

  { 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },

  { 0, 2, 8, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },

  { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 }

};

/* Predict motion vectors using those from already-decoded nearby blocks.

   Note that we only consider one 4x4 subblock from each candidate 16x16

   macroblock.   */

void vp8_find_near_mvs(MACROBLOCKD *xd, const MODE_INFO *here, int_mv *nearest,

                       int_mv *nearby, int_mv *best_mv, int near_mv_ref_cnts[4],

                       int refframe, int *ref_frame_sign_bias) {

  const MODE_INFO *above = here - xd->mode_info_stride;

  const MODE_INFO *left = here - 1;

  const MODE_INFO *aboveleft = above - 1;

  int_mv near_mvs[4];

  int_mv *mv = near_mvs;

  int *cntx = near_mv_ref_cnts;

  enum { CNT_INTRA, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV };

  /* Zero accumulators */

  mv[0].as_int = mv[1].as_int = mv[2].as_int = 0;

  near_mv_ref_cnts[0] = near_mv_ref_cnts[1] = near_mv_ref_cnts[2] =

      near_mv_ref_cnts[3] = 0;

  /* Process above */

  if (above->mbmi.ref_frame != INTRA_FRAME) {

    if (above->mbmi.mv.as_int) {

      (++mv)->as_int = above->mbmi.mv.as_int;

      mv_bias(ref_frame_sign_bias[above->mbmi.ref_frame], refframe, mv,

              ref_frame_sign_bias);

      ++cntx;

    }

    *cntx += 2;

  }

  /* Process left */

  if (left->mbmi.ref_frame != INTRA_FRAME) {

    if (left->mbmi.mv.as_int) {

      int_mv this_mv;

      this_mv.as_int = left->mbmi.mv.as_int;

      mv_bias(ref_frame_sign_bias[left->mbmi.ref_frame], refframe, &this_mv,

              ref_frame_sign_bias);

      if (this_mv.as_int != mv->as_int) {

        (++mv)->as_int = this_mv.as_int;

        ++cntx;

      }

      *cntx += 2;

    } else {

      near_mv_ref_cnts[CNT_INTRA] += 2;

    }

  }

  /* Process above left */

  if (aboveleft->mbmi.ref_frame != INTRA_FRAME) {

    if (aboveleft->mbmi.mv.as_int) {

      int_mv this_mv;

      this_mv.as_int = aboveleft->mbmi.mv.as_int;

      mv_bias(ref_frame_sign_bias[aboveleft->mbmi.ref_frame], refframe,

              &this_mv, ref_frame_sign_bias);

      if (this_mv.as_int != mv->as_int) {

        (++mv)->as_int = this_mv.as_int;

        ++cntx;

      }

      *cntx += 1;

    } else {

      near_mv_ref_cnts[CNT_INTRA] += 1;

    }

  }

  /* If we have three distinct MV's ... */

  if (near_mv_ref_cnts[CNT_SPLITMV]) {

    /* See if above-left MV can be merged with NEAREST */

    if (mv->as_int == near_mvs[CNT_NEAREST].as_int)

      near_mv_ref_cnts[CNT_NEAREST] += 1;

  }

  near_mv_ref_cnts[CNT_SPLITMV] =

      ((above->mbmi.mode == SPLITMV) + (left->mbmi.mode == SPLITMV)) * 2 +

      (aboveleft->mbmi.mode == SPLITMV);

  /* Swap near and nearest if necessary */

  if (near_mv_ref_cnts[CNT_NEAR] > near_mv_ref_cnts[CNT_NEAREST]) {

    int tmp;

    tmp = near_mv_ref_cnts[CNT_NEAREST];

    near_mv_ref_cnts[CNT_NEAREST] = near_mv_ref_cnts[CNT_NEAR];

    near_mv_ref_cnts[CNT_NEAR] = tmp;

    tmp = (int)near_mvs[CNT_NEAREST].as_int;

    near_mvs[CNT_NEAREST].as_int = near_mvs[CNT_NEAR].as_int;

    near_mvs[CNT_NEAR].as_int = (uint32_t)tmp;

  }

  /* Use near_mvs[0] to store the "best" MV */

  if (near_mv_ref_cnts[CNT_NEAREST] >= near_mv_ref_cnts[CNT_INTRA]) {

    near_mvs[CNT_INTRA] = near_mvs[CNT_NEAREST];

  }

  /* Set up return values */

  best_mv->as_int = near_mvs[0].as_int;

  nearest->as_int = near_mvs[CNT_NEAREST].as_int;

  nearby->as_int = near_mvs[CNT_NEAR].as_int;

}

static void invert_and_clamp_mvs(int_mv *inv, int_mv *src, MACROBLOCKD *xd) {

  inv->as_mv.row = src->as_mv.row * -1;

  inv->as_mv.col = src->as_mv.col * -1;

  vp8_clamp_mv2(inv, xd);

  vp8_clamp_mv2(src, xd);

}

int vp8_find_near_mvs_bias(MACROBLOCKD *xd, const MODE_INFO *here,

                           int_mv mode_mv_sb[2][MB_MODE_COUNT],

                           int_mv best_mv_sb[2], int cnt[4], int refframe,

                           int *ref_frame_sign_bias) {

  int sign_bias = ref_frame_sign_bias[refframe];

  vp8_find_near_mvs(xd, here, &mode_mv_sb[sign_bias][NEARESTMV],

                    &mode_mv_sb[sign_bias][NEARMV], &best_mv_sb[sign_bias], cnt,

                    refframe, ref_frame_sign_bias);

  invert_and_clamp_mvs(&mode_mv_sb[!sign_bias][NEARESTMV],

                       &mode_mv_sb[sign_bias][NEARESTMV], xd);

  invert_and_clamp_mvs(&mode_mv_sb[!sign_bias][NEARMV],

                       &mode_mv_sb[sign_bias][NEARMV], xd);

  invert_and_clamp_mvs(&best_mv_sb[!sign_bias], &best_mv_sb[sign_bias], xd);

  return sign_bias;

}

vp8_prob *vp8_mv_ref_probs(vp8_prob p[VP8_MVREFS - 1],

                           const int near_mv_ref_ct[4]) {

  p[0] = vp8_mode_contexts[near_mv_ref_ct[0]][0];

  p[1] = vp8_mode_contexts[near_mv_ref_ct[1]][1];

  p[2] = vp8_mode_contexts[near_mv_ref_ct[2]][2];

  p[3] = vp8_mode_contexts[near_mv_ref_ct[3]][3];

  /* p[3] = vp8_mode_contexts[near_mv_ref_ct[1] + near_mv_ref_ct[2] +

                           near_mv_ref_ct[3]][3]; */

  return p;

}