text: /*
   * Copyright (c) 2020, Alliance for Open Media. All rights reserved
   *
   * This source code is subject to the terms of the BSD 2 Clause License and
   * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
   * was not distributed with this source code in the LICENSE file, you can
   * obtain it at www.aomedia.org/license/software. If the Alliance for Open
   * Media Patent License 1.0 was not distributed with this source code in the
   * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
   */
  
  #include "aom_ports/system_state.h"
  
  #include "av1/common/reconinter.h"
  
  #include "av1/encoder/encodemv.h"
  #include "av1/encoder/encoder.h"
  #include "av1/encoder/mcomp.h"
  #include "av1/encoder/motion_search_facade.h"
  #include "av1/encoder/partition_strategy.h"
  #include "av1/encoder/reconinter_enc.h"
  #include "av1/encoder/tpl_model.h"
  
  #define RIGHT_SHIFT_MV(x) (((x) + 3 + ((x) >= 0)) >> 3)
  
  typedef struct {
    FULLPEL_MV fmv;
    int weight;
  } cand_mv_t;
  
  static int compare_weight(const void *a, const void *b) {
    const int diff = ((cand_mv_t *)a)->weight - ((cand_mv_t *)b)->weight;
    if (diff < 0)
      return 1;
    else if (diff > 0)
      return -1;
    return 0;
  }
  
  // Allow more mesh searches for screen content type on the ARF.
  static int use_fine_search_interval(const AV1_COMP *const cpi) {
    return cpi->is_screen_content_type &&
           cpi->gf_group.update_type[cpi->gf_group.index] == ARF_UPDATE &&
           cpi->oxcf.speed <= 2;
  }
  
  void av1_single_motion_search(const AV1_COMP *const cpi, MACROBLOCK *x,
                                BLOCK_SIZE bsize, int ref_idx, int *rate_mv,
                                int search_range, inter_mode_info *mode_info,
                                int_mv *best_mv) {
    MACROBLOCKD *xd = &x->e_mbd;
    const AV1_COMMON *cm = &cpi->common;
    const MotionVectorSearchParams *mv_search_params = &cpi->mv_search_params;
    const int num_planes = av1_num_planes(cm);
    MB_MODE_INFO *mbmi = xd->mi[0];
    struct buf_2d backup_yv12[MAX_MB_PLANE] = { { 0, 0, 0, 0, 0 } };
    int bestsme = INT_MAX;
    const int ref = mbmi->ref_frame[ref_idx];
    const YV12_BUFFER_CONFIG *scaled_ref_frame =
        av1_get_scaled_ref_frame(cpi, ref);
    const int mi_row = xd->mi_row;
    const int mi_col = xd->mi_col;
    const MvCosts *mv_costs = &x->mv_costs;
  
    if (scaled_ref_frame) {
      // Swap out the reference frame for a version that's been scaled to
      // match the resolution of the current frame, allowing the existing
      // full-pixel motion search code to be used without additional
      // modifications.
      for (int i = 0; i < num_planes; i++) {
        backup_yv12[i] = xd->plane[i].pre[ref_idx];
      }
      av1_setup_pre_planes(xd, ref_idx, scaled_ref_frame, mi_row, mi_col, NULL,
                           num_planes);
    }
  
    // Work out the size of the first step in the mv step search.
    // 0 here is maximum length first step. 1 is AOMMAX >> 1 etc.
    int step_param;
    if (cpi->sf.mv_sf.auto_mv_step_size && cm->show_frame) {
      // Take the weighted average of the step_params based on the last frame's
      // max mv magnitude and that based on the best ref mvs of the current
      // block for the given reference.
      step_param = (av1_init_search_range(x->max_mv_context[ref]) +
                    mv_search_params->mv_step_param) /
                   2;
    } else {
      step_param = mv_search_params->mv_step_param;
    }
  
    const MV ref_mv = av1_get_ref_mv(x, ref_idx).as_mv;
    FULLPEL_MV start_mv;
    if (mbmi->motion_mode != SIMPLE_TRANSLATION)
      start_mv = get_fullmv_from_mv(&mbmi->mv[0].as_mv);
    else
      start_mv = get_fullmv_from_mv(&ref_mv);
  
    // cand stores start_mv and all possible MVs in a SB.
    cand_mv_t cand[MAX_TPL_BLK_IN_SB * MAX_TPL_BLK_IN_SB + 1] = { { { 0, 0 },
                                                                    0 } };
    cand[0].fmv = start_mv;
    int cnt = 1;
    int total_weight = 0;
  
    if (!cpi->sf.mv_sf.full_pixel_search_level &&
        mbmi->motion_mode == SIMPLE_TRANSLATION) {
      SuperBlockEnc *sb_enc = &x->sb_enc;
      if (sb_enc->tpl_data_count) {
        const BLOCK_SIZE tpl_bsize =
            convert_length_to_bsize(cpi->tpl_data.tpl_bsize_1d);
        const int tplw = mi_size_wide[tpl_bsize];
        const int tplh = mi_size_high[tpl_bsize];
        const int nw = mi_size_wide[bsize] / tplw;
        const int nh = mi_size_high[bsize] / tplh;
  
        if (nw >= 1 && nh >= 1) {
          const int of_h = mi_row % mi_size_high[cm->seq_params.sb_size];
          const int of_w = mi_col % mi_size_wide[cm->seq_params.sb_size];
          const int start = of_h / tplh * sb_enc->tpl_stride + of_w / tplw;
          int valid = 1;
  
          // Assign large weight to start_mv, so it is always tested.
          cand[0].weight = nw * nh;
  
          for (int k = 0; k < nh; k++) {
            for (int l = 0; l < nw; l++) {
              const int_mv mv = sb_enc->tpl_mv[start + k * sb_enc->tpl_stride + l]
                                              [ref - LAST_FRAME];
              if (mv.as_int == INVALID_MV) {
                valid = 0;
                break;
              }
  
              const FULLPEL_MV fmv = { GET_MV_RAWPEL(mv.as_mv.row),
                                       GET_MV_RAWPEL(mv.as_mv.col) };
              int unique = 1;
              for (int m = 0; m < cnt; m++) {
                if (RIGHT_SHIFT_MV(fmv.row) == RIGHT_SHIFT_MV(cand[m].fmv.row) &&
                    RIGHT_SHIFT_MV(fmv.col) == RIGHT_SHIFT_MV(cand[m].fmv.col)) {
                  unique = 0;
                  cand[m].weight++;
                  break;
                }
              }
  
              if (unique) {
                cand[cnt].fmv = fmv;
                cand[cnt].weight = 1;
                cnt++;
              }
            }
            if (!valid) break;
          }
  
          if (valid) {
            total_weight = 2 * nh * nw;
            if (cnt > 2) qsort(cand, cnt, sizeof(cand[0]), &compare_weight);
          }
        }
      }
    }
  
    // Further reduce the search range.
    if (search_range < INT_MAX) {
      const search_site_config *search_site_cfg =
          &mv_search_params
               ->search_site_cfg[SS_CFG_SRC][cpi->sf.mv_sf.search_method];
      // Max step_param is search_site_cfg->num_search_steps.
      if (search_range < 1) {
        step_param = search_site_cfg->num_search_steps;
      } else {
        while (search_site_cfg->radius[search_site_cfg->num_search_steps -
                                       step_param - 1] > (search_range << 1) &&
               search_site_cfg->num_search_steps - step_param - 1 > 0)
          step_param++;
      }
    }
  
    int cost_list[5];
    int_mv second_best_mv;
    best_mv->as_int = second_best_mv.as_int = INVALID_MV;
  
    // Allow more mesh searches for screen content type on the ARF.
    const int fine_search_interval = use_fine_search_interval(cpi);
    const search_site_config *src_search_sites =
        mv_search_params->search_site_cfg[SS_CFG_SRC];
    FULLPEL_MOTION_SEARCH_PARAMS full_ms_params;
    av1_make_default_fullpel_ms_params(&full_ms_params, cpi, x, bsize, &ref_mv,
                                       src_search_sites, fine_search_interval);
  
    switch (mbmi->motion_mode) {
      case SIMPLE_TRANSLATION: {
        int sum_weight = 0;
  
        for (int m = 0; m < cnt; m++) {
          FULLPEL_MV smv = cand[m].fmv;
          FULLPEL_MV this_best_mv, this_second_best_mv;
  
          int thissme = av1_full_pixel_search(
              smv, &full_ms_params, step_param, cond_cost_list(cpi, cost_list),
              &this_best_mv, &this_second_best_mv);
  
          if (thissme < bestsme) {
            bestsme = thissme;
            best_mv->as_fullmv = this_best_mv;
            second_best_mv.as_fullmv = this_second_best_mv;
          }
  
          sum_weight += cand[m].weight;
          if (m >= 2 || 4 * sum_weight > 3 * total_weight) break;
        }
      } break;
      case OBMC_CAUSAL:
        bestsme = av1_obmc_full_pixel_search(start_mv, &full_ms_params,
                                             step_param, &best_mv->as_fullmv);
        break;
      default: assert(0 && "Invalid motion mode!\n");
    }
  
    if (scaled_ref_frame) {
      // Swap back the original buffers for subpel motion search.
      for (int i = 0; i < num_planes; i++) {
        xd->plane[i].pre[ref_idx] = backup_yv12[i];
      }
    }
  
    // Terminate search with the current ref_idx if we have already encountered
    // another ref_mv in the drl such that:
    //  1. The other drl has the same fullpel_mv during the SIMPLE_TRANSLATION
    //     search process as the current fullpel_mv.
    //  2. The rate needed to encode the current fullpel_mv is larger than that
    //     for the other ref_mv.
    if (cpi->sf.inter_sf.skip_repeated_full_newmv &&
        mbmi->motion_mode == SIMPLE_TRANSLATION &&
        best_mv->as_int != INVALID_MV) {
      int_mv this_mv;
      this_mv.as_mv = get_mv_from_fullmv(&best_mv->as_fullmv);
      const int ref_mv_idx = mbmi->ref_mv_idx;
      const int this_mv_rate =
          av1_mv_bit_cost(&this_mv.as_mv, &ref_mv, mv_costs->nmv_joint_cost,
                          mv_costs->mv_cost_stack, MV_COST_WEIGHT);
      mode_info[ref_mv_idx].full_search_mv.as_int = this_mv.as_int;
      mode_info[ref_mv_idx].full_mv_rate = this_mv_rate;
  
      for (int prev_ref_idx = 0; prev_ref_idx < ref_mv_idx; ++prev_ref_idx) {
        // Check if the motion search result same as previous results
        if (this_mv.as_int == mode_info[prev_ref_idx].full_search_mv.as_int) {
          // Compare the rate cost
          const int prev_rate_cost = mode_info[prev_ref_idx].full_mv_rate +
                                     mode_info[prev_ref_idx].drl_cost;
          const int this_rate_cost =
              this_mv_rate + mode_info[ref_mv_idx].drl_cost;
  
          if (prev_rate_cost <= this_rate_cost) {
            // If the current rate_cost is worse than the previous rate_cost, then
            // we terminate the search. Since av1_single_motion_search is only
            // called by handle_new_mv in SIMPLE_TRANSLATION mode, we set the
            // best_mv to INVALID mv to signal that we wish to terminate search
            // for the current mode.
            best_mv->as_int = INVALID_MV;
            return;
          }
        }
      }
    }
  
    if (cpi->common.features.cur_frame_force_integer_mv) {
      convert_fullmv_to_mv(best_mv);
    }
  
    const int use_fractional_mv =
        bestsme < INT_MAX && cpi->common.features.cur_frame_force_integer_mv == 0;
    if (use_fractional_mv) {
      int_mv fractional_ms_list[3];
      av1_set_fractional_mv(fractional_ms_list);
      int dis; /* TODO: use dis in distortion calculation later. */
  
      SUBPEL_MOTION_SEARCH_PARAMS ms_params;
      av1_make_default_subpel_ms_params(&ms_params, cpi, x, bsize, &ref_mv,
                                        cost_list);
      MV subpel_start_mv = get_mv_from_fullmv(&best_mv->as_fullmv);
  
      switch (mbmi->motion_mode) {
        case SIMPLE_TRANSLATION:
          if (cpi->sf.mv_sf.use_accurate_subpel_search) {
            const int try_second = second_best_mv.as_int != INVALID_MV &&
                                   second_best_mv.as_int != best_mv->as_int;
            const int best_mv_var = mv_search_params->find_fractional_mv_step(
                xd, cm, &ms_params, subpel_start_mv, &best_mv->as_mv, &dis,
                &x->pred_sse[ref], fractional_ms_list);
  
            if (try_second) {
              MV this_best_mv;
              subpel_start_mv = get_mv_from_fullmv(&second_best_mv.as_fullmv);
              if (av1_is_subpelmv_in_range(&ms_params.mv_limits,
                                           subpel_start_mv)) {
                const int this_var = mv_search_params->find_fractional_mv_step(
                    xd, cm, &ms_params, subpel_start_mv, &this_best_mv, &dis,
                    &x->pred_sse[ref], fractional_ms_list);
                if (this_var < best_mv_var) best_mv->as_mv = this_best_mv;
              }
            }
          } else {
            mv_search_params->find_fractional_mv_step(
                xd, cm, &ms_params, subpel_start_mv, &best_mv->as_mv, &dis,
                &x->pred_sse[ref], NULL);
          }
          break;
        case OBMC_CAUSAL:
          av1_find_best_obmc_sub_pixel_tree_up(xd, cm, &ms_params,
                                               subpel_start_mv, &best_mv->as_mv,
                                               &dis, &x->pred_sse[ref], NULL);
          break;
        default: assert(0 && "Invalid motion mode!\n");
      }
    }
    *rate_mv = av1_mv_bit_cost(&best_mv->as_mv, &ref_mv, mv_costs->nmv_joint_cost,
                               mv_costs->mv_cost_stack, MV_COST_WEIGHT);
  }
  
  void av1_joint_motion_search(const AV1_COMP *cpi, MACROBLOCK *x,
                               BLOCK_SIZE bsize, int_mv *cur_mv,
                               const uint8_t *mask, int mask_stride,
                               int *rate_mv) {
    const AV1_COMMON *const cm = &cpi->common;
    const int num_planes = av1_num_planes(cm);
    const int pw = block_size_wide[bsize];
    const int ph = block_size_high[bsize];
    const int plane = 0;
    MACROBLOCKD *xd = &x->e_mbd;
    MB_MODE_INFO *mbmi = xd->mi[0];
    // This function should only ever be called for compound modes
    assert(has_second_ref(mbmi));
    const int_mv init_mv[2] = { cur_mv[0], cur_mv[1] };
    const int refs[2] = { mbmi->ref_frame[0], mbmi->ref_frame[1] };
    const MvCosts *mv_costs = &x->mv_costs;
    int_mv ref_mv[2];
    int ite, ref;
  
    // Get the prediction block from the 'other' reference frame.
    const int_interpfilters interp_filters =
        av1_broadcast_interp_filter(EIGHTTAP_REGULAR);
  
    InterPredParams inter_pred_params;
    const int mi_row = xd->mi_row;
    const int mi_col = xd->mi_col;
  
    // Do joint motion search in compound mode to get more accurate mv.
    struct buf_2d backup_yv12[2][MAX_MB_PLANE];
    int last_besterr[2] = { INT_MAX, INT_MAX };
    const YV12_BUFFER_CONFIG *const scaled_ref_frame[2] = {
      av1_get_scaled_ref_frame(cpi, refs[0]),
      av1_get_scaled_ref_frame(cpi, refs[1])
    };
  
    // Prediction buffer from second frame.
    DECLARE_ALIGNED(16, uint8_t, second_pred16[MAX_SB_SQUARE * sizeof(uint16_t)]);
    uint8_t *second_pred = get_buf_by_bd(xd, second_pred16);
    int_mv best_mv;
  
    // Allow joint search multiple times iteratively for each reference frame
    // and break out of the search loop if it couldn't find a better mv.
    for (ite = 0; ite < 4; ite++) {
      struct buf_2d ref_yv12[2];
      int bestsme = INT_MAX;
      int id = ite % 2;  // Even iterations search in the first reference frame,
                         // odd iterations search in the second. The predictor
                         // found for the 'other' reference frame is factored in.
      if (ite >= 2 && cur_mv[!id].as_int == init_mv[!id].as_int) {
        if (cur_mv[id].as_int == init_mv[id].as_int) {
          break;
        } else {
          int_mv cur_int_mv, init_int_mv;
          cur_int_mv.as_mv.col = cur_mv[id].as_mv.col >> 3;
          cur_int_mv.as_mv.row = cur_mv[id].as_mv.row >> 3;
          init_int_mv.as_mv.row = init_mv[id].as_mv.row >> 3;
          init_int_mv.as_mv.col = init_mv[id].as_mv.col >> 3;
          if (cur_int_mv.as_int == init_int_mv.as_int) {
            break;
          }
        }
      }
      for (ref = 0; ref < 2; ++ref) {
        ref_mv[ref] = av1_get_ref_mv(x, ref);
        // Swap out the reference frame for a version that's been scaled to
        // match the resolution of the current frame, allowing the existing
        // motion search code to be used without additional modifications.
        if (scaled_ref_frame[ref]) {
          int i;
          for (i = 0; i < num_planes; i++)
            backup_yv12[ref][i] = xd->plane[i].pre[ref];
          av1_setup_pre_planes(xd, ref, scaled_ref_frame[ref], mi_row, mi_col,
                               NULL, num_planes);
        }
      }
  
      assert(IMPLIES(scaled_ref_frame[0] != NULL,
                     cm->width == scaled_ref_frame[0]->y_crop_width &&
                         cm->height == scaled_ref_frame[0]->y_crop_height));
      assert(IMPLIES(scaled_ref_frame[1] != NULL,
                     cm->width == scaled_ref_frame[1]->y_crop_width &&
                         cm->height == scaled_ref_frame[1]->y_crop_height));
  
      // Initialize based on (possibly scaled) prediction buffers.
      ref_yv12[0] = xd->plane[plane].pre[0];
      ref_yv12[1] = xd->plane[plane].pre[1];
  
      av1_init_inter_params(&inter_pred_params, pw, ph, mi_row * MI_SIZE,
                            mi_col * MI_SIZE, 0, 0, xd->bd, is_cur_buf_hbd(xd), 0,
                            &cm->sf_identity, &ref_yv12[!id], interp_filters);
      inter_pred_params.conv_params = get_conv_params(0, 0, xd->bd);
  
      // Since we have scaled the reference frames to match the size of the
      // current frame we must use a unit scaling factor during mode selection.
      av1_enc_build_one_inter_predictor(second_pred, pw, &cur_mv[!id].as_mv,
                                        &inter_pred_params);
  
      // Do full-pixel compound motion search on the current reference frame.
      if (id) xd->plane[plane].pre[0] = ref_yv12[id];
  
      // Make motion search params
      FULLPEL_MOTION_SEARCH_PARAMS full_ms_params;
      av1_make_default_fullpel_ms_params(&full_ms_params, cpi, x, bsize,
                                         &ref_mv[id].as_mv, NULL,
                                         /*fine_search_interval=*/0);
  
      av1_set_ms_compound_refs(&full_ms_params.ms_buffers, second_pred, mask,
                               mask_stride, id);
  
      // Use the mv result from the single mode as mv predictor.
      const FULLPEL_MV start_fullmv = get_fullmv_from_mv(&cur_mv[id].as_mv);
  
      // Small-range full-pixel motion search.
      bestsme = av1_refining_search_8p_c(&full_ms_params, start_fullmv,
                                         &best_mv.as_fullmv);
  
      if (bestsme < INT_MAX) {
        bestsme = av1_get_mvpred_compound_var(
            &full_ms_params.mv_cost_params, best_mv.as_fullmv, second_pred, mask,
            mask_stride, id, &cpi->fn_ptr[bsize], &x->plane[0].src,
            &ref_yv12[id]);
      }
  
      // Restore the pointer to the first (possibly scaled) prediction buffer.
      if (id) xd->plane[plane].pre[0] = ref_yv12[0];
  
      for (ref = 0; ref < 2; ++ref) {
        if (scaled_ref_frame[ref]) {
          // Swap back the original buffers for subpel motion search.
          for (int i = 0; i < num_planes; i++) {
            xd->plane[i].pre[ref] = backup_yv12[ref][i];
          }
          // Re-initialize based on unscaled prediction buffers.
          ref_yv12[ref] = xd->plane[plane].pre[ref];
        }
      }
  
      // Do sub-pixel compound motion search on the current reference frame.
      if (id) xd->plane[plane].pre[0] = ref_yv12[id];
  
      if (cpi->common.features.cur_frame_force_integer_mv) {
        convert_fullmv_to_mv(&best_mv);
      }
      if (bestsme < INT_MAX &&
          cpi->common.features.cur_frame_force_integer_mv == 0) {
        int dis; /* TODO: use dis in distortion calculation later. */
        unsigned int sse;
        SUBPEL_MOTION_SEARCH_PARAMS ms_params;
        av1_make_default_subpel_ms_params(&ms_params, cpi, x, bsize,
                                          &ref_mv[id].as_mv, NULL);
        av1_set_ms_compound_refs(&ms_params.var_params.ms_buffers, second_pred,
                                 mask, mask_stride, id);
        ms_params.forced_stop = EIGHTH_PEL;
        MV start_mv = get_mv_from_fullmv(&best_mv.as_fullmv);
        bestsme = cpi->mv_search_params.find_fractional_mv_step(
            xd, cm, &ms_params, start_mv, &best_mv.as_mv, &dis, &sse, NULL);
      }
  
      // Restore the pointer to the first prediction buffer.
      if (id) xd->plane[plane].pre[0] = ref_yv12[0];
      if (bestsme < last_besterr[id]) {
        cur_mv[id] = best_mv;
        last_besterr[id] = bestsme;
      } else {
        break;
      }
    }
  
    *rate_mv = 0;
  
    for (ref = 0; ref < 2; ++ref) {
      const int_mv curr_ref_mv = av1_get_ref_mv(x, ref);
      *rate_mv += av1_mv_bit_cost(&cur_mv[ref].as_mv, &curr_ref_mv.as_mv,
                                  mv_costs->nmv_joint_cost,
                                  mv_costs->mv_cost_stack, MV_COST_WEIGHT);
    }
  }
  
  // Search for the best mv for one component of a compound,
  // given that the other component is fixed.
  void av1_compound_single_motion_search(const AV1_COMP *cpi, MACROBLOCK *x,
                                         BLOCK_SIZE bsize, MV *this_mv,
                                         const uint8_t *second_pred,
                                         const uint8_t *mask, int mask_stride,
                                         int *rate_mv, int ref_idx) {
    const AV1_COMMON *const cm = &cpi->common;
    const int num_planes = av1_num_planes(cm);
    MACROBLOCKD *xd = &x->e_mbd;
    MB_MODE_INFO *mbmi = xd->mi[0];
    const int ref = mbmi->ref_frame[ref_idx];
    const int_mv ref_mv = av1_get_ref_mv(x, ref_idx);
    struct macroblockd_plane *const pd = &xd->plane[0];
    const MvCosts *mv_costs = &x->mv_costs;
  
    struct buf_2d backup_yv12[MAX_MB_PLANE];
    const YV12_BUFFER_CONFIG *const scaled_ref_frame =
        av1_get_scaled_ref_frame(cpi, ref);
  
    // Check that this is either an interinter or an interintra block
    assert(has_second_ref(mbmi) || (ref_idx == 0 && is_interintra_mode(mbmi)));
  
    // Store the first prediction buffer.
    struct buf_2d orig_yv12;
    struct buf_2d ref_yv12 = pd->pre[ref_idx];
    if (ref_idx) {
      orig_yv12 = pd->pre[0];
      pd->pre[0] = pd->pre[ref_idx];
    }
  
    if (scaled_ref_frame) {
      // Swap out the reference frame for a version that's been scaled to
      // match the resolution of the current frame, allowing the existing
      // full-pixel motion search code to be used without additional
      // modifications.
      for (int i = 0; i < num_planes; i++) {
        backup_yv12[i] = xd->plane[i].pre[ref_idx];
      }
      const int mi_row = xd->mi_row;
      const int mi_col = xd->mi_col;
      av1_setup_pre_planes(xd, ref_idx, scaled_ref_frame, mi_row, mi_col, NULL,
                           num_planes);
    }
  
    int bestsme = INT_MAX;
    int_mv best_mv;
  
    // Make motion search params
    FULLPEL_MOTION_SEARCH_PARAMS full_ms_params;
    av1_make_default_fullpel_ms_params(&full_ms_params, cpi, x, bsize,
                                       &ref_mv.as_mv, NULL,
                                       /*fine_search_interval=*/0);
  
    av1_set_ms_compound_refs(&full_ms_params.ms_buffers, second_pred, mask,
                             mask_stride, ref_idx);
  
    // Use the mv result from the single mode as mv predictor.
    const FULLPEL_MV start_fullmv = get_fullmv_from_mv(this_mv);
  
    // Small-range full-pixel motion search.
    bestsme = av1_refining_search_8p_c(&full_ms_params, start_fullmv,
                                       &best_mv.as_fullmv);
  
    if (bestsme < INT_MAX) {
      bestsme = av1_get_mvpred_compound_var(
          &full_ms_params.mv_cost_params, best_mv.as_fullmv, second_pred, mask,
          mask_stride, ref_idx, &cpi->fn_ptr[bsize], &x->plane[0].src, &ref_yv12);
    }
  
    if (scaled_ref_frame) {
      // Swap back the original buffers for subpel motion search.
      for (int i = 0; i < num_planes; i++) {
        xd->plane[i].pre[ref_idx] = backup_yv12[i];
      }
    }
  
    if (cpi->common.features.cur_frame_force_integer_mv) {
      convert_fullmv_to_mv(&best_mv);
    }
    const int use_fractional_mv =
        bestsme < INT_MAX && cpi->common.features.cur_frame_force_integer_mv == 0;
    if (use_fractional_mv) {
      int dis; /* TODO: use dis in distortion calculation later. */
      unsigned int sse;
      SUBPEL_MOTION_SEARCH_PARAMS ms_params;
      av1_make_default_subpel_ms_params(&ms_params, cpi, x, bsize, &ref_mv.as_mv,
                                        NULL);
      av1_set_ms_compound_refs(&ms_params.var_params.ms_buffers, second_pred,
                               mask, mask_stride, ref_idx);
      ms_params.forced_stop = EIGHTH_PEL;
      MV start_mv = get_mv_from_fullmv(&best_mv.as_fullmv);
      bestsme = cpi->mv_search_params.find_fractional_mv_step(
          xd, cm, &ms_params, start_mv, &best_mv.as_mv, &dis, &sse, NULL);
    }
  
    // Restore the pointer to the first unscaled prediction buffer.
    if (ref_idx) pd->pre[0] = orig_yv12;
  
    if (bestsme < INT_MAX) *this_mv = best_mv.as_mv;
  
    *rate_mv = 0;
  
    *rate_mv += av1_mv_bit_cost(this_mv, &ref_mv.as_mv, mv_costs->nmv_joint_cost,
                                mv_costs->mv_cost_stack, MV_COST_WEIGHT);
  }
  
  static AOM_INLINE void build_second_inter_pred(const AV1_COMP *cpi,
                                                 MACROBLOCK *x, BLOCK_SIZE bsize,
                                                 const MV *other_mv, int ref_idx,
                                                 uint8_t *second_pred) {
    const AV1_COMMON *const cm = &cpi->common;
    const int pw = block_size_wide[bsize];
    const int ph = block_size_high[bsize];
    MACROBLOCKD *xd = &x->e_mbd;
    MB_MODE_INFO *mbmi = xd->mi[0];
    struct macroblockd_plane *const pd = &xd->plane[0];
    const int mi_row = xd->mi_row;
    const int mi_col = xd->mi_col;
    const int p_col = ((mi_col * MI_SIZE) >> pd->subsampling_x);
    const int p_row = ((mi_row * MI_SIZE) >> pd->subsampling_y);
  
    // This function should only ever be called for compound modes
    assert(has_second_ref(mbmi));
  
    const int plane = 0;
    struct buf_2d ref_yv12 = xd->plane[plane].pre[!ref_idx];
  
    struct scale_factors sf;
    av1_setup_scale_factors_for_frame(&sf, ref_yv12.width, ref_yv12.height,
                                      cm->width, cm->height);
  
    InterPredParams inter_pred_params;
  
    av1_init_inter_params(&inter_pred_params, pw, ph, p_row, p_col,
                          pd->subsampling_x, pd->subsampling_y, xd->bd,
                          is_cur_buf_hbd(xd), 0, &sf, &ref_yv12,
                          mbmi->interp_filters);
    inter_pred_params.conv_params = get_conv_params(0, plane, xd->bd);
  
    // Get the prediction block from the 'other' reference frame.
    av1_enc_build_one_inter_predictor(second_pred, pw, other_mv,
                                      &inter_pred_params);
  }
  
  // Wrapper for av1_compound_single_motion_search, for the common case
  // where the second prediction is also an inter mode.
  void av1_compound_single_motion_search_interinter(
      const AV1_COMP *cpi, MACROBLOCK *x, BLOCK_SIZE bsize, int_mv *cur_mv,
      const uint8_t *mask, int mask_stride, int *rate_mv, int ref_idx) {
    MACROBLOCKD *xd = &x->e_mbd;
    // This function should only ever be called for compound modes
    assert(has_second_ref(xd->mi[0]));
  
    // Prediction buffer from second frame.
    DECLARE_ALIGNED(16, uint16_t, second_pred_alloc_16[MAX_SB_SQUARE]);
    uint8_t *second_pred;
    if (is_cur_buf_hbd(xd))
      second_pred = CONVERT_TO_BYTEPTR(second_pred_alloc_16);
    else
      second_pred = (uint8_t *)second_pred_alloc_16;
  
    MV *this_mv = &cur_mv[ref_idx].as_mv;
    const MV *other_mv = &cur_mv[!ref_idx].as_mv;
    build_second_inter_pred(cpi, x, bsize, other_mv, ref_idx, second_pred);
    av1_compound_single_motion_search(cpi, x, bsize, this_mv, second_pred, mask,
                                      mask_stride, rate_mv, ref_idx);
  }
  
  static AOM_INLINE void do_masked_motion_search_indexed(
      const AV1_COMP *const cpi, MACROBLOCK *x, const int_mv *const cur_mv,
      const INTERINTER_COMPOUND_DATA *const comp_data, BLOCK_SIZE bsize,
      int_mv *tmp_mv, int *rate_mv, int which) {
    // NOTE: which values: 0 - 0 only, 1 - 1 only, 2 - both
    MACROBLOCKD *xd = &x->e_mbd;
    MB_MODE_INFO *mbmi = xd->mi[0];
    BLOCK_SIZE sb_type = mbmi->bsize;
    const uint8_t *mask;
    const int mask_stride = block_size_wide[bsize];
  
    mask = av1_get_compound_type_mask(comp_data, sb_type);
  
    tmp_mv[0].as_int = cur_mv[0].as_int;
    tmp_mv[1].as_int = cur_mv[1].as_int;
    if (which == 0 || which == 1) {
      av1_compound_single_motion_search_interinter(cpi, x, bsize, tmp_mv, mask,
                                                   mask_stride, rate_mv, which);
    } else if (which == 2) {
      av1_joint_motion_search(cpi, x, bsize, tmp_mv, mask, mask_stride, rate_mv);
    }
  }
  
  int av1_interinter_compound_motion_search(const AV1_COMP *const cpi,
                                            MACROBLOCK *x,
                                            const int_mv *const cur_mv,
                                            const BLOCK_SIZE bsize,
                                            const PREDICTION_MODE this_mode) {
    MACROBLOCKD *const xd = &x->e_mbd;
    MB_MODE_INFO *const mbmi = xd->mi[0];
    int_mv tmp_mv[2];
    int tmp_rate_mv = 0;
    mbmi->interinter_comp.seg_mask = xd->seg_mask;
    const INTERINTER_COMPOUND_DATA *compound_data = &mbmi->interinter_comp;
  
    if (this_mode == NEW_NEWMV) {
      do_masked_motion_search_indexed(cpi, x, cur_mv, compound_data, bsize,
                                      tmp_mv, &tmp_rate_mv, 2);
      mbmi->mv[0].as_int = tmp_mv[0].as_int;
      mbmi->mv[1].as_int = tmp_mv[1].as_int;
    } else if (this_mode >= NEAREST_NEWMV && this_mode <= NEW_NEARMV) {
      // which = 1 if this_mode == NEAREST_NEWMV || this_mode == NEAR_NEWMV
      // which = 0 if this_mode == NEW_NEARESTMV || this_mode == NEW_NEARMV
      int which = (NEWMV == compound_ref1_mode(this_mode));
      do_masked_motion_search_indexed(cpi, x, cur_mv, compound_data, bsize,
                                      tmp_mv, &tmp_rate_mv, which);
      mbmi->mv[which].as_int = tmp_mv[which].as_int;
    }
    return tmp_rate_mv;
  }
  
  int_mv av1_simple_motion_search(AV1_COMP *const cpi, MACROBLOCK *x, int mi_row,
                                  int mi_col, BLOCK_SIZE bsize, int ref,
                                  FULLPEL_MV start_mv, int num_planes,
                                  int use_subpixel) {
    assert(num_planes == 1 &&
           "Currently simple_motion_search only supports luma plane");
    assert(!frame_is_intra_only(&cpi->common) &&
           "Simple motion search only enabled for non-key frames");
    AV1_COMMON *const cm = &cpi->common;
    MACROBLOCKD *xd = &x->e_mbd;
  
    set_offsets_for_motion_search(cpi, x, mi_row, mi_col, bsize);
  
    MB_MODE_INFO *mbmi = xd->mi[0];
    mbmi->bsize = bsize;
    mbmi->ref_frame[0] = ref;
    mbmi->ref_frame[1] = NONE_FRAME;
    mbmi->motion_mode = SIMPLE_TRANSLATION;
    mbmi->interp_filters = av1_broadcast_interp_filter(EIGHTTAP_REGULAR);
  
    const YV12_BUFFER_CONFIG *yv12 = get_ref_frame_yv12_buf(cm, ref);
    const YV12_BUFFER_CONFIG *scaled_ref_frame =
        av1_get_scaled_ref_frame(cpi, ref);
    struct buf_2d backup_yv12;
    // ref_mv is used to calculate the cost of the motion vector
    const MV ref_mv = kZeroMv;
    const int step_param =
        AOMMIN(cpi->mv_search_params.mv_step_param +
                   cpi->sf.part_sf.simple_motion_search_reduce_search_steps,
               MAX_MVSEARCH_STEPS - 2);
    const search_site_config *src_search_sites =
        cpi->mv_search_params.search_site_cfg[SS_CFG_SRC];
    int cost_list[5];
    const int ref_idx = 0;
    int var;
    int_mv best_mv;
  
    av1_setup_pre_planes(xd, ref_idx, yv12, mi_row, mi_col,
                         get_ref_scale_factors(cm, ref), num_planes);
    set_ref_ptrs(cm, xd, mbmi->ref_frame[0], mbmi->ref_frame[1]);
    if (scaled_ref_frame) {
      backup_yv12 = xd->plane[AOM_PLANE_Y].pre[ref_idx];
      av1_setup_pre_planes(xd, ref_idx, scaled_ref_frame, mi_row, mi_col, NULL,
                           num_planes);
    }
  
    // Allow more mesh searches for screen content type on the ARF.
    const int fine_search_interval = use_fine_search_interval(cpi);
    FULLPEL_MOTION_SEARCH_PARAMS full_ms_params;
    av1_make_default_fullpel_ms_params(&full_ms_params, cpi, x, bsize, &ref_mv,
                                       src_search_sites, fine_search_interval);
  
    var = av1_full_pixel_search(start_mv, &full_ms_params, step_param,
                                cond_cost_list(cpi, cost_list),
                                &best_mv.as_fullmv, NULL);
  
    const int use_subpel_search =
        var < INT_MAX && !cpi->common.features.cur_frame_force_integer_mv &&
        use_subpixel;
    if (scaled_ref_frame) {
      xd->plane[AOM_PLANE_Y].pre[ref_idx] = backup_yv12;
    }
    if (use_subpel_search) {
      int not_used = 0;
  
      SUBPEL_MOTION_SEARCH_PARAMS ms_params;
      av1_make_default_subpel_ms_params(&ms_params, cpi, x, bsize, &ref_mv,
                                        cost_list);
      // TODO(yunqing): integrate this into av1_make_default_subpel_ms_params().
      ms_params.forced_stop = cpi->sf.mv_sf.simple_motion_subpel_force_stop;
  
      MV subpel_start_mv = get_mv_from_fullmv(&best_mv.as_fullmv);
  
      cpi->mv_search_params.find_fractional_mv_step(
          xd, cm, &ms_params, subpel_start_mv, &best_mv.as_mv, &not_used,
          &x->pred_sse[ref], NULL);
    } else {
      // Manually convert from units of pixel to 1/8-pixels if we are not doing
      // subpel search
      convert_fullmv_to_mv(&best_mv);
    }
  
    mbmi->mv[0] = best_mv;
  
    // Get a copy of the prediction output
    av1_enc_build_inter_predictor(cm, xd, mi_row, mi_col, NULL, bsize,
                                  AOM_PLANE_Y, AOM_PLANE_Y);
  
    aom_clear_system_state();
  
    if (scaled_ref_frame) {
      xd->plane[AOM_PLANE_Y].pre[ref_idx] = backup_yv12;
    }
  
    return best_mv;
  }
  
  int_mv av1_simple_motion_sse_var(AV1_COMP *cpi, MACROBLOCK *x, int mi_row,
                                   int mi_col, BLOCK_SIZE bsize,
                                   const FULLPEL_MV start_mv, int use_subpixel,
                                   unsigned int *sse, unsigned int *var) {
    MACROBLOCKD *xd = &x->e_mbd;
    const MV_REFERENCE_FRAME ref =
        cpi->rc.is_src_frame_alt_ref ? ALTREF_FRAME : LAST_FRAME;
  
    int_mv best_mv = av1_simple_motion_search(cpi, x, mi_row, mi_col, bsize, ref,
                                              start_mv, 1, use_subpixel);
  
    const uint8_t *src = x->plane[0].src.buf;
    const int src_stride = x->plane[0].src.stride;
    const uint8_t *dst = xd->plane[0].dst.buf;
    const int dst_stride = xd->plane[0].dst.stride;
  
    *var = cpi->fn_ptr[bsize].vf(src, src_stride, dst, dst_stride, sse);
  
    return best_mv;
  }
  