vp9_encodeframe.c

  for (i = 0; i < MAX_MB_PLANE; ++i) {
    p[i].coeff = ctx->coeff_pbuf[i][0];
    p[i].qcoeff = ctx->qcoeff_pbuf[i][0];
    pd[i].dqcoeff = ctx->dqcoeff_pbuf[i][0];
    p[i].eobs = ctx->eobs_pbuf[i][0];
  }
  ctx->is_coded = 0;
  x->skip_recode = 0;

  // Set to zero to make sure we do not use the previous encoded frame stats
  mbmi->skip = 0;

  x->source_variance = get_sby_perpixel_variance(cpi, &x->plane[0].src, bsize);

  // Save rdmult before it might be changed, so it can be restored later.
  orig_rdmult = x->rdmult;
  if (cpi->oxcf.tuning == VP8_TUNE_SSIM)
    activity_masking(cpi, x);

  if (aq_mode == VARIANCE_AQ) {
    const int energy = bsize <= BLOCK_16X16 ? x->mb_energy
                                            : vp9_block_energy(cpi, x, bsize);
    if (cm->frame_type == KEY_FRAME ||
        cpi->refresh_alt_ref_frame ||
        (cpi->refresh_golden_frame && !cpi->rc.is_src_frame_alt_ref)) {
      mbmi->segment_id = vp9_vaq_segment_id(energy);
    } else {
      const uint8_t *const map = cm->seg.update_map ? cpi->segmentation_map
                                                    : cm->last_frame_seg_map;
      mbmi->segment_id = vp9_get_segment_id(cm, map, bsize, mi_row, mi_col);
    }

    rdmult_ratio = vp9_vaq_rdmult_ratio(energy);
    vp9_init_plane_quantizers(cpi, x);
    vp9_clear_system_state();
    x->rdmult = (int)round(x->rdmult * rdmult_ratio);
  } else if (aq_mode == COMPLEXITY_AQ) {
    const int mi_offset = mi_row * cm->mi_cols + mi_col;
    unsigned char complexity = cpi->complexity_map[mi_offset];
    const int is_edge = (mi_row <= 1) || (mi_row >= (cm->mi_rows - 2)) ||
                        (mi_col <= 1) || (mi_col >= (cm->mi_cols - 2));
    if (!is_edge && (complexity > 128))
      x->rdmult += ((x->rdmult * (complexity - 128)) / 256);
  } else if (aq_mode == CYCLIC_REFRESH_AQ) {
    const uint8_t *const map = cm->seg.update_map ? cpi->segmentation_map
                                                  : cm->last_frame_seg_map;
    // If segment 1, use rdmult for that segment.
    if (vp9_get_segment_id(cm, map, bsize, mi_row, mi_col))
      x->rdmult = vp9_cyclic_refresh_get_rdmult(cpi->cyclic_refresh);
  }

  // Find best coding mode & reconstruct the MB so it is available
  // as a predictor for MBs that follow in the SB
  if (frame_is_intra_only(cm)) {
    vp9_rd_pick_intra_mode_sb(cpi, x, totalrate, totaldist, bsize, ctx,
                              best_rd);
  } else {
    if (bsize >= BLOCK_8X8)
      vp9_rd_pick_inter_mode_sb(cpi, x, tile, mi_row, mi_col,
                                totalrate, totaldist, bsize, ctx, best_rd);
    else
      vp9_rd_pick_inter_mode_sub8x8(cpi, x, tile, mi_row, mi_col, totalrate,
                                    totaldist, bsize, ctx, best_rd);
  }

  x->rdmult = orig_rdmult;

  if (aq_mode == VARIANCE_AQ && *totalrate != INT_MAX) {
    vp9_clear_system_state();
    *totalrate = (int)round(*totalrate * rdmult_ratio);
  }
}

static void update_stats(VP9_COMP *cpi) {
  VP9_COMMON *const cm = &cpi->common;
  const MACROBLOCK *const x = &cpi->mb;
  const MACROBLOCKD *const xd = &x->e_mbd;
  const MODE_INFO *const mi = xd->mi[0];
  const MB_MODE_INFO *const mbmi = &mi->mbmi;

  if (!frame_is_intra_only(cm)) {
    const int seg_ref_active = vp9_segfeature_active(&cm->seg, mbmi->segment_id,
                                                     SEG_LVL_REF_FRAME);
    if (!seg_ref_active) {
      FRAME_COUNTS *const counts = &cm->counts;
      const int inter_block = is_inter_block(mbmi);

      counts->intra_inter[vp9_get_intra_inter_context(xd)][inter_block]++;

      // If the segment reference feature is enabled we have only a single
      // reference frame allowed for the segment so exclude it from
      // the reference frame counts used to work out probabilities.
      if (inter_block) {
        const MV_REFERENCE_FRAME ref0 = mbmi->ref_frame[0];

        if (cm->reference_mode == REFERENCE_MODE_SELECT)
          counts->comp_inter[vp9_get_reference_mode_context(cm, xd)]
                            [has_second_ref(mbmi)]++;

        if (has_second_ref(mbmi)) {
          counts->comp_ref[vp9_get_pred_context_comp_ref_p(cm, xd)]
                          [ref0 == GOLDEN_FRAME]++;
        } else {
          counts->single_ref[vp9_get_pred_context_single_ref_p1(xd)][0]
                            [ref0 != LAST_FRAME]++;
          if (ref0 != LAST_FRAME)
            counts->single_ref[vp9_get_pred_context_single_ref_p2(xd)][1]
                              [ref0 != GOLDEN_FRAME]++;
        }
      }
    }
  }
}

static BLOCK_SIZE *get_sb_partitioning(MACROBLOCK *x, BLOCK_SIZE bsize) {
  switch (bsize) {
    case BLOCK_64X64:
      return &x->sb64_partitioning;
    case BLOCK_32X32:
      return &x->sb_partitioning[x->sb_index];
    case BLOCK_16X16:
      return &x->mb_partitioning[x->sb_index][x->mb_index];
    case BLOCK_8X8:
      return &x->b_partitioning[x->sb_index][x->mb_index][x->b_index];
    default:
      assert(0);
      return NULL;
  }
}

static void restore_context(VP9_COMP *cpi, int mi_row, int mi_col,
                            ENTROPY_CONTEXT a[16 * MAX_MB_PLANE],
                            ENTROPY_CONTEXT l[16 * MAX_MB_PLANE],
                            PARTITION_CONTEXT sa[8], PARTITION_CONTEXT sl[8],
                            BLOCK_SIZE bsize) {
  MACROBLOCK *const x = &cpi->mb;
  MACROBLOCKD *const xd = &x->e_mbd;
  int p;
  const int num_4x4_blocks_wide = num_4x4_blocks_wide_lookup[bsize];
  const int num_4x4_blocks_high = num_4x4_blocks_high_lookup[bsize];
  int mi_width = num_8x8_blocks_wide_lookup[bsize];
  int mi_height = num_8x8_blocks_high_lookup[bsize];
  for (p = 0; p < MAX_MB_PLANE; p++) {
    vpx_memcpy(
        xd->above_context[p] + ((mi_col * 2) >> xd->plane[p].subsampling_x),
        a + num_4x4_blocks_wide * p,
        (sizeof(ENTROPY_CONTEXT) * num_4x4_blocks_wide) >>
        xd->plane[p].subsampling_x);
    vpx_memcpy(
        xd->left_context[p]
            + ((mi_row & MI_MASK) * 2 >> xd->plane[p].subsampling_y),
        l + num_4x4_blocks_high * p,
        (sizeof(ENTROPY_CONTEXT) * num_4x4_blocks_high) >>
        xd->plane[p].subsampling_y);
  }
  vpx_memcpy(xd->above_seg_context + mi_col, sa,
             sizeof(*xd->above_seg_context) * mi_width);
  vpx_memcpy(xd->left_seg_context + (mi_row & MI_MASK), sl,
             sizeof(xd->left_seg_context[0]) * mi_height);
}
static void save_context(VP9_COMP *cpi, int mi_row, int mi_col,
                         ENTROPY_CONTEXT a[16 * MAX_MB_PLANE],
                         ENTROPY_CONTEXT l[16 * MAX_MB_PLANE],
                         PARTITION_CONTEXT sa[8], PARTITION_CONTEXT sl[8],
                         BLOCK_SIZE bsize) {
  const MACROBLOCK *const x = &cpi->mb;
  const MACROBLOCKD *const xd = &x->e_mbd;
  int p;
  const int num_4x4_blocks_wide = num_4x4_blocks_wide_lookup[bsize];
  const int num_4x4_blocks_high = num_4x4_blocks_high_lookup[bsize];
  int mi_width = num_8x8_blocks_wide_lookup[bsize];
  int mi_height = num_8x8_blocks_high_lookup[bsize];

  // buffer the above/left context information of the block in search.
  for (p = 0; p < MAX_MB_PLANE; ++p) {
    vpx_memcpy(
        a + num_4x4_blocks_wide * p,
        xd->above_context[p] + (mi_col * 2 >> xd->plane[p].subsampling_x),
        (sizeof(ENTROPY_CONTEXT) * num_4x4_blocks_wide) >>
        xd->plane[p].subsampling_x);
    vpx_memcpy(
        l + num_4x4_blocks_high * p,
        xd->left_context[p]
            + ((mi_row & MI_MASK) * 2 >> xd->plane[p].subsampling_y),
        (sizeof(ENTROPY_CONTEXT) * num_4x4_blocks_high) >>
        xd->plane[p].subsampling_y);
  }
  vpx_memcpy(sa, xd->above_seg_context + mi_col,
             sizeof(*xd->above_seg_context) * mi_width);
  vpx_memcpy(sl, xd->left_seg_context + (mi_row & MI_MASK),
             sizeof(xd->left_seg_context[0]) * mi_height);
}

static void encode_b(VP9_COMP *cpi, const TileInfo *const tile,
                     TOKENEXTRA **tp, int mi_row, int mi_col,
                     int output_enabled, BLOCK_SIZE bsize) {
  MACROBLOCK *const x = &cpi->mb;

  if (bsize < BLOCK_8X8) {
    // When ab_index = 0 all sub-blocks are handled, so for ab_index != 0
    // there is nothing to be done.
    if (x->ab_index > 0)
      return;
  }
  set_offsets(cpi, tile, mi_row, mi_col, bsize);
  update_state(cpi, get_block_context(x, bsize), mi_row, mi_col, bsize,
               output_enabled);
  encode_superblock(cpi, tp, output_enabled, mi_row, mi_col, bsize);

  if (output_enabled) {
    update_stats(cpi);

    (*tp)->token = EOSB_TOKEN;
    (*tp)++;
  }
}

static void encode_sb(VP9_COMP *cpi, const TileInfo *const tile,
                      TOKENEXTRA **tp, int mi_row, int mi_col,
                      int output_enabled, BLOCK_SIZE bsize) {
  VP9_COMMON *const cm = &cpi->common;
  MACROBLOCK *const x = &cpi->mb;
  MACROBLOCKD *const xd = &x->e_mbd;

  const int bsl = b_width_log2(bsize), hbs = (1 << bsl) / 4;
  int ctx;
  PARTITION_TYPE partition;
  BLOCK_SIZE subsize;

  if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols)
    return;

  if (bsize >= BLOCK_8X8) {
    ctx = partition_plane_context(xd, mi_row, mi_col, bsize);
    subsize = *get_sb_partitioning(x, bsize);
  } else {
    ctx = 0;
    subsize = BLOCK_4X4;
  }

  partition = partition_lookup[bsl][subsize];

  switch (partition) {
    case PARTITION_NONE:
      if (output_enabled && bsize >= BLOCK_8X8)
        cm->counts.partition[ctx][PARTITION_NONE]++;
      encode_b(cpi, tile, tp, mi_row, mi_col, output_enabled, subsize);
      break;
    case PARTITION_VERT:
      if (output_enabled)
        cm->counts.partition[ctx][PARTITION_VERT]++;
      *get_sb_index(x, subsize) = 0;
      encode_b(cpi, tile, tp, mi_row, mi_col, output_enabled, subsize);
      if (mi_col + hbs < cm->mi_cols) {
        *get_sb_index(x, subsize) = 1;
        encode_b(cpi, tile, tp, mi_row, mi_col + hbs, output_enabled, subsize);
      }
      break;
    case PARTITION_HORZ:
      if (output_enabled)
        cm->counts.partition[ctx][PARTITION_HORZ]++;
      *get_sb_index(x, subsize) = 0;
      encode_b(cpi, tile, tp, mi_row, mi_col, output_enabled, subsize);
      if (mi_row + hbs < cm->mi_rows) {
        *get_sb_index(x, subsize) = 1;
        encode_b(cpi, tile, tp, mi_row + hbs, mi_col, output_enabled, subsize);
      }
      break;
    case PARTITION_SPLIT:
      subsize = get_subsize(bsize, PARTITION_SPLIT);
      if (output_enabled)
        cm->counts.partition[ctx][PARTITION_SPLIT]++;

      *get_sb_index(x, subsize) = 0;
      encode_sb(cpi, tile, tp, mi_row, mi_col, output_enabled, subsize);
      *get_sb_index(x, subsize) = 1;
      encode_sb(cpi, tile, tp, mi_row, mi_col + hbs, output_enabled, subsize);
      *get_sb_index(x, subsize) = 2;
      encode_sb(cpi, tile, tp, mi_row + hbs, mi_col, output_enabled, subsize);
      *get_sb_index(x, subsize) = 3;
      encode_sb(cpi, tile, tp, mi_row + hbs, mi_col + hbs, output_enabled,
                subsize);
      break;
    default:
      assert("Invalid partition type.");
  }

  if (partition != PARTITION_SPLIT || bsize == BLOCK_8X8)
    update_partition_context(xd, mi_row, mi_col, subsize, bsize);
}

// Check to see if the given partition size is allowed for a specified number
// of 8x8 block rows and columns remaining in the image.
// If not then return the largest allowed partition size
static BLOCK_SIZE find_partition_size(BLOCK_SIZE bsize,
                                      int rows_left, int cols_left,
                                      int *bh, int *bw) {
  if (rows_left <= 0 || cols_left <= 0) {
    return MIN(bsize, BLOCK_8X8);
  } else {
    for (; bsize > 0; bsize -= 3) {
      *bh = num_8x8_blocks_high_lookup[bsize];
      *bw = num_8x8_blocks_wide_lookup[bsize];
      if ((*bh <= rows_left) && (*bw <= cols_left)) {
        break;
      }
    }
  }
  return bsize;
}

// This function attempts to set all mode info entries in a given SB64
// to the same block partition size.
// However, at the bottom and right borders of the image the requested size
// may not be allowed in which case this code attempts to choose the largest
// allowable partition.
static void set_fixed_partitioning(VP9_COMP *cpi, const TileInfo *const tile,
                                   MODE_INFO **mi_8x8, int mi_row, int mi_col,
                                   BLOCK_SIZE bsize) {
  VP9_COMMON *const cm = &cpi->common;
  const int mis = cm->mi_stride;
  int row8x8_remaining = tile->mi_row_end - mi_row;
  int col8x8_remaining = tile->mi_col_end - mi_col;
  int block_row, block_col;
  MODE_INFO *mi_upper_left = cm->mi + mi_row * mis + mi_col;
  int bh = num_8x8_blocks_high_lookup[bsize];
  int bw = num_8x8_blocks_wide_lookup[bsize];

  assert((row8x8_remaining > 0) && (col8x8_remaining > 0));

  // Apply the requested partition size to the SB64 if it is all "in image"
  if ((col8x8_remaining >= MI_BLOCK_SIZE) &&
      (row8x8_remaining >= MI_BLOCK_SIZE)) {
    for (block_row = 0; block_row < MI_BLOCK_SIZE; block_row += bh) {
      for (block_col = 0; block_col < MI_BLOCK_SIZE; block_col += bw) {
        int index = block_row * mis + block_col;
        mi_8x8[index] = mi_upper_left + index;
        mi_8x8[index]->mbmi.sb_type = bsize;
      }
    }
  } else {
    // Else this is a partial SB64.
    for (block_row = 0; block_row < MI_BLOCK_SIZE; block_row += bh) {
      for (block_col = 0; block_col < MI_BLOCK_SIZE; block_col += bw) {
        int index = block_row * mis + block_col;
        // Find a partition size that fits
        bsize = find_partition_size(bsize,
                                    (row8x8_remaining - block_row),
                                    (col8x8_remaining - block_col), &bh, &bw);
        mi_8x8[index] = mi_upper_left + index;
        mi_8x8[index]->mbmi.sb_type = bsize;
      }
    }
  }
}

static void copy_partitioning(VP9_COMMON *cm, MODE_INFO **mi_8x8,
  MODE_INFO **prev_mi_8x8) {
  const int mis = cm->mi_stride;
  int block_row, block_col;

  for (block_row = 0; block_row < 8; ++block_row) {
    for (block_col = 0; block_col < 8; ++block_col) {
      MODE_INFO *const prev_mi = prev_mi_8x8[block_row * mis + block_col];
      const BLOCK_SIZE sb_type = prev_mi ? prev_mi->mbmi.sb_type : 0;

      if (prev_mi) {
        const ptrdiff_t offset = prev_mi - cm->prev_mi;
        mi_8x8[block_row * mis + block_col] = cm->mi + offset;
        mi_8x8[block_row * mis + block_col]->mbmi.sb_type = sb_type;
      }
    }
  }
}

static void constrain_copy_partitioning(VP9_COMP *const cpi,
                                        const TileInfo *const tile,
                                        MODE_INFO **mi_8x8,
                                        MODE_INFO **prev_mi_8x8,
                                        int mi_row, int mi_col,
                                        BLOCK_SIZE bsize) {
  VP9_COMMON *const cm = &cpi->common;
  const int mis = cm->mi_stride;
  const int row8x8_remaining = tile->mi_row_end - mi_row;
  const int col8x8_remaining = tile->mi_col_end - mi_col;
  MODE_INFO *const mi_upper_left = cm->mi + mi_row * mis + mi_col;
  const int bh = num_8x8_blocks_high_lookup[bsize];
  const int bw = num_8x8_blocks_wide_lookup[bsize];
  int block_row, block_col;

  assert((row8x8_remaining > 0) && (col8x8_remaining > 0));

  // If the SB64 if it is all "in image".
  if ((col8x8_remaining >= MI_BLOCK_SIZE) &&
      (row8x8_remaining >= MI_BLOCK_SIZE)) {
    for (block_row = 0; block_row < MI_BLOCK_SIZE; block_row += bh) {
      for (block_col = 0; block_col < MI_BLOCK_SIZE; block_col += bw) {
        const int index = block_row * mis + block_col;
        MODE_INFO *prev_mi = prev_mi_8x8[index];
        const BLOCK_SIZE sb_type = prev_mi ? prev_mi->mbmi.sb_type : 0;
        // Use previous partition if block size is not larger than bsize.
        if (prev_mi && sb_type <= bsize) {
          int block_row2, block_col2;
          for (block_row2 = 0; block_row2 < bh; ++block_row2) {
            for (block_col2 = 0; block_col2 < bw; ++block_col2) {
              const int index2 = (block_row + block_row2) * mis +
                  block_col + block_col2;
              prev_mi = prev_mi_8x8[index2];
              if (prev_mi) {
                const ptrdiff_t offset = prev_mi - cm->prev_mi;
                mi_8x8[index2] = cm->mi + offset;
                mi_8x8[index2]->mbmi.sb_type = prev_mi->mbmi.sb_type;
              }
            }
          }
        } else {
          // Otherwise, use fixed partition of size bsize.
          mi_8x8[index] = mi_upper_left + index;
          mi_8x8[index]->mbmi.sb_type = bsize;
        }
      }
    }
  } else {
    // Else this is a partial SB64, copy previous partition.
    copy_partitioning(cm, mi_8x8, prev_mi_8x8);
  }
}


const struct {
  int row;
  int col;
} coord_lookup[16] = {
    // 32x32 index = 0
    {0, 0}, {0, 2}, {2, 0}, {2, 2},
    // 32x32 index = 1
    {0, 4}, {0, 6}, {2, 4}, {2, 6},
    // 32x32 index = 2
    {4, 0}, {4, 2}, {6, 0}, {6, 2},
    // 32x32 index = 3
    {4, 4}, {4, 6}, {6, 4}, {6, 6},
};

static void set_source_var_based_partition(VP9_COMP *cpi,
                                           const TileInfo *const tile,
                                           MODE_INFO **mi_8x8,
                                           int mi_row, int mi_col) {
  VP9_COMMON *const cm = &cpi->common;
  MACROBLOCK *const x = &cpi->mb;
  const int mis = cm->mi_stride;
  const int row8x8_remaining = tile->mi_row_end - mi_row;
  const int col8x8_remaining = tile->mi_col_end - mi_col;
  MODE_INFO *mi_upper_left = cm->mi + mi_row * mis + mi_col;

  vp9_setup_src_planes(x, cpi->Source, mi_row, mi_col);

  assert((row8x8_remaining > 0) && (col8x8_remaining > 0));

  // In-image SB64
  if ((col8x8_remaining >= MI_BLOCK_SIZE) &&
      (row8x8_remaining >= MI_BLOCK_SIZE)) {
    const int src_stride = x->plane[0].src.stride;
    const int pre_stride = cpi->Last_Source->y_stride;
    const uint8_t *src = x->plane[0].src.buf;
    const int pre_offset = (mi_row * MI_SIZE) * pre_stride +
                           (mi_col * MI_SIZE);
    const uint8_t *pre_src = cpi->Last_Source->y_buffer + pre_offset;
    const unsigned int thr_32x32 = cpi->sf.source_var_thresh;
    const unsigned int thr_64x64 = thr_32x32 << 1;
    int i, j;
    int index;
    diff d32[4];
    int use16x16 = 0;

    for (i = 0; i < 4; i++) {
      diff d16[4];

      for (j = 0; j < 4; j++) {
        int b_mi_row = coord_lookup[i * 4 + j].row;
        int b_mi_col = coord_lookup[i * 4 + j].col;
        int b_offset = b_mi_row * MI_SIZE * src_stride +
                       b_mi_col * MI_SIZE;

        vp9_get_sse_sum_16x16(src + b_offset,
                              src_stride,
                              pre_src + b_offset,
                              pre_stride, &d16[j].sse, &d16[j].sum);

        d16[j].var = d16[j].sse -
            (((uint32_t)d16[j].sum * d16[j].sum) >> 8);

        index = b_mi_row * mis + b_mi_col;
        mi_8x8[index] = mi_upper_left + index;
        mi_8x8[index]->mbmi.sb_type = BLOCK_16X16;

        // TODO(yunqingwang): If d16[j].var is very large, use 8x8 partition
        // size to further improve quality.
      }

      if (d16[0].var < thr_32x32 && d16[1].var < thr_32x32 &&
          d16[2].var < thr_32x32 && d16[3].var < thr_32x32) {
        d32[i].sse = d16[0].sse;
        d32[i].sum = d16[0].sum;

        for (j = 1; j < 4; j++) {
          d32[i].sse += d16[j].sse;
          d32[i].sum += d16[j].sum;
        }

        d32[i].var = d32[i].sse - (((int64_t)d32[i].sum * d32[i].sum) >> 10);

        index = coord_lookup[i*4].row * mis + coord_lookup[i*4].col;
        mi_8x8[index] = mi_upper_left + index;
        mi_8x8[index]->mbmi.sb_type = BLOCK_32X32;

        if (!((cm->current_video_frame - 1) %
            cpi->sf.search_type_check_frequency))
          cpi->use_large_partition_rate += 1;
      } else {
        use16x16 = 1;
      }
    }

    if (!use16x16) {
      if (d32[0].var < thr_64x64 && d32[1].var < thr_64x64 &&
          d32[2].var < thr_64x64 && d32[3].var < thr_64x64)  {
        mi_8x8[0] = mi_upper_left;
        mi_8x8[0]->mbmi.sb_type = BLOCK_64X64;
      }
    }
  } else {   // partial in-image SB64
    BLOCK_SIZE bsize = BLOCK_16X16;
    int bh = num_8x8_blocks_high_lookup[bsize];
    int bw = num_8x8_blocks_wide_lookup[bsize];
    int r, c;
    for (r = 0; r < MI_BLOCK_SIZE; r += bh) {
      for (c = 0; c < MI_BLOCK_SIZE; c += bw) {
        const int index = r * mis + c;
        mi_8x8[index] = mi_upper_left + index;
        mi_8x8[index]->mbmi.sb_type = find_partition_size(bsize,
            row8x8_remaining - r, col8x8_remaining - c, &bh, &bw);
      }
    }
  }
}

static int sb_has_motion(const VP9_COMMON *cm, MODE_INFO **prev_mi_8x8) {
  const int mis = cm->mi_stride;
  int block_row, block_col;

  if (cm->prev_mi) {
    for (block_row = 0; block_row < 8; ++block_row) {
      for (block_col = 0; block_col < 8; ++block_col) {
        const MODE_INFO *prev_mi = prev_mi_8x8[block_row * mis + block_col];
        if (prev_mi) {
          if (abs(prev_mi->mbmi.mv[0].as_mv.row) >= 8 ||
              abs(prev_mi->mbmi.mv[0].as_mv.col) >= 8)
            return 1;
        }
      }
    }
  }
  return 0;
}

static void update_state_rt(VP9_COMP *cpi, PICK_MODE_CONTEXT *ctx,
                            int mi_row, int mi_col, int bsize) {
  VP9_COMMON *const cm = &cpi->common;
  MACROBLOCK *const x = &cpi->mb;
  MACROBLOCKD *const xd = &x->e_mbd;
  MB_MODE_INFO *const mbmi = &xd->mi[0]->mbmi;
  const struct segmentation *const seg = &cm->seg;

  *(xd->mi[0]) = ctx->mic;

  // For in frame adaptive Q, check for reseting the segment_id and updating
  // the cyclic refresh map.
  if ((cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ) && seg->enabled) {
    vp9_cyclic_refresh_update_segment(cpi, &xd->mi[0]->mbmi,
                                      mi_row, mi_col, bsize, 1);
    vp9_init_plane_quantizers(cpi, x);
  }

  if (is_inter_block(mbmi)) {
    vp9_update_mv_count(cm, xd);

    if (cm->interp_filter == SWITCHABLE) {
      const int pred_ctx = vp9_get_pred_context_switchable_interp(xd);
      ++cm->counts.switchable_interp[pred_ctx][mbmi->interp_filter];
    }
  }

  x->skip = ctx->skip;
}

static void encode_b_rt(VP9_COMP *cpi, const TileInfo *const tile,
                        TOKENEXTRA **tp, int mi_row, int mi_col,
                        int output_enabled, BLOCK_SIZE bsize) {
  MACROBLOCK *const x = &cpi->mb;

  if (bsize < BLOCK_8X8) {
    // When ab_index = 0 all sub-blocks are handled, so for ab_index != 0
    // there is nothing to be done.
    if (x->ab_index > 0)
      return;
  }

  set_offsets(cpi, tile, mi_row, mi_col, bsize);
  update_state_rt(cpi, get_block_context(x, bsize), mi_row, mi_col, bsize);

  encode_superblock(cpi, tp, output_enabled, mi_row, mi_col, bsize);
  update_stats(cpi);

  (*tp)->token = EOSB_TOKEN;
  (*tp)++;
}

static void encode_sb_rt(VP9_COMP *cpi, const TileInfo *const tile,
                         TOKENEXTRA **tp, int mi_row, int mi_col,
                         int output_enabled, BLOCK_SIZE bsize) {
  VP9_COMMON *const cm = &cpi->common;
  MACROBLOCK *const x = &cpi->mb;
  MACROBLOCKD *const xd = &x->e_mbd;

  const int bsl = b_width_log2(bsize), hbs = (1 << bsl) / 4;
  int ctx;
  PARTITION_TYPE partition;
  BLOCK_SIZE subsize;

  if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols)
    return;

  if (bsize >= BLOCK_8X8) {
    MACROBLOCKD *const xd = &cpi->mb.e_mbd;
    const int idx_str = xd->mi_stride * mi_row + mi_col;
    MODE_INFO ** mi_8x8 = cm->mi_grid_visible + idx_str;
    ctx = partition_plane_context(xd, mi_row, mi_col, bsize);
    subsize = mi_8x8[0]->mbmi.sb_type;
  } else {
    ctx = 0;
    subsize = BLOCK_4X4;
  }

  partition = partition_lookup[bsl][subsize];

  switch (partition) {
    case PARTITION_NONE:
      if (output_enabled && bsize >= BLOCK_8X8)
        cm->counts.partition[ctx][PARTITION_NONE]++;
      encode_b_rt(cpi, tile, tp, mi_row, mi_col, output_enabled, subsize);
      break;
    case PARTITION_VERT:
      if (output_enabled)
        cm->counts.partition[ctx][PARTITION_VERT]++;
      *get_sb_index(x, subsize) = 0;
      encode_b_rt(cpi, tile, tp, mi_row, mi_col, output_enabled, subsize);
      if (mi_col + hbs < cm->mi_cols) {
        *get_sb_index(x, subsize) = 1;
        encode_b_rt(cpi, tile, tp, mi_row, mi_col + hbs, output_enabled,
                    subsize);
      }
      break;
    case PARTITION_HORZ:
      if (output_enabled)
        cm->counts.partition[ctx][PARTITION_HORZ]++;
      *get_sb_index(x, subsize) = 0;
      encode_b_rt(cpi, tile, tp, mi_row, mi_col, output_enabled, subsize);
      if (mi_row + hbs < cm->mi_rows) {
        *get_sb_index(x, subsize) = 1;
        encode_b_rt(cpi, tile, tp, mi_row + hbs, mi_col, output_enabled,
                    subsize);
      }
      break;
    case PARTITION_SPLIT:
      subsize = get_subsize(bsize, PARTITION_SPLIT);
      if (output_enabled)
        cm->counts.partition[ctx][PARTITION_SPLIT]++;

      *get_sb_index(x, subsize) = 0;
      encode_sb_rt(cpi, tile, tp, mi_row, mi_col, output_enabled, subsize);
      *get_sb_index(x, subsize) = 1;
      encode_sb_rt(cpi, tile, tp, mi_row, mi_col + hbs, output_enabled,
                   subsize);
      *get_sb_index(x, subsize) = 2;
      encode_sb_rt(cpi, tile, tp, mi_row + hbs, mi_col, output_enabled,
                   subsize);
      *get_sb_index(x, subsize) = 3;
      encode_sb_rt(cpi, tile, tp, mi_row + hbs, mi_col + hbs, output_enabled,
                   subsize);
      break;
    default:
      assert("Invalid partition type.");
  }

  if (partition != PARTITION_SPLIT || bsize == BLOCK_8X8)
    update_partition_context(xd, mi_row, mi_col, subsize, bsize);
}

static void rd_use_partition(VP9_COMP *cpi,
                             const TileInfo *const tile,
                             MODE_INFO **mi_8x8,
                             TOKENEXTRA **tp, int mi_row, int mi_col,
                             BLOCK_SIZE bsize, int *rate, int64_t *dist,
                             int do_recon) {
  VP9_COMMON *const cm = &cpi->common;
  MACROBLOCK *const x = &cpi->mb;
  MACROBLOCKD *const xd = &x->e_mbd;
  const int mis = cm->mi_stride;
  const int bsl = b_width_log2(bsize);
  const int mi_step = num_4x4_blocks_wide_lookup[bsize] / 2;
  const int bss = (1 << bsl) / 4;
  int i, pl;
  PARTITION_TYPE partition = PARTITION_NONE;
  BLOCK_SIZE subsize;
  ENTROPY_CONTEXT l[16 * MAX_MB_PLANE], a[16 * MAX_MB_PLANE];
  PARTITION_CONTEXT sl[8], sa[8];
  int last_part_rate = INT_MAX;
  int64_t last_part_dist = INT64_MAX;
  int64_t last_part_rd = INT64_MAX;
  int none_rate = INT_MAX;
  int64_t none_dist = INT64_MAX;
  int64_t none_rd = INT64_MAX;
  int chosen_rate = INT_MAX;
  int64_t chosen_dist = INT64_MAX;
  int64_t chosen_rd = INT64_MAX;
  BLOCK_SIZE sub_subsize = BLOCK_4X4;
  int splits_below = 0;
  BLOCK_SIZE bs_type = mi_8x8[0]->mbmi.sb_type;
  int do_partition_search = 1;

  if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols)
    return;

  assert(num_4x4_blocks_wide_lookup[bsize] ==
         num_4x4_blocks_high_lookup[bsize]);

  partition = partition_lookup[bsl][bs_type];
  subsize = get_subsize(bsize, partition);

  if (bsize < BLOCK_8X8) {
    // When ab_index = 0 all sub-blocks are handled, so for ab_index != 0
    // there is nothing to be done.
    if (x->ab_index != 0) {
      *rate = 0;
      *dist = 0;
      return;
    }
  } else {
    *(get_sb_partitioning(x, bsize)) = subsize;
  }
  save_context(cpi, mi_row, mi_col, a, l, sa, sl, bsize);

  if (bsize == BLOCK_16X16) {
    set_offsets(cpi, tile, mi_row, mi_col, bsize);
    x->mb_energy = vp9_block_energy(cpi, x, bsize);
  } else {
    x->in_active_map = check_active_map(cpi, x, mi_row, mi_col, bsize);
  }

  if (!x->in_active_map) {
    do_partition_search = 0;
    if (mi_row + (mi_step >> 1) < cm->mi_rows &&
        mi_col + (mi_step >> 1) < cm->mi_cols) {
      *(get_sb_partitioning(x, bsize)) = bsize;
      bs_type = mi_8x8[0]->mbmi.sb_type = bsize;
      subsize = bsize;
      partition = PARTITION_NONE;
    }
  }
  if (do_partition_search &&
      cpi->sf.partition_search_type == SEARCH_PARTITION &&
      cpi->sf.adjust_partitioning_from_last_frame) {
    // Check if any of the sub blocks are further split.
    if (partition == PARTITION_SPLIT && subsize > BLOCK_8X8) {
      sub_subsize = get_subsize(subsize, PARTITION_SPLIT);
      splits_below = 1;
      for (i = 0; i < 4; i++) {
        int jj = i >> 1, ii = i & 0x01;
        MODE_INFO * this_mi = mi_8x8[jj * bss * mis + ii * bss];
        if (this_mi && this_mi->mbmi.sb_type >= sub_subsize) {
          splits_below = 0;
        }
      }
    }

    // If partition is not none try none unless each of the 4 splits are split
    // even further..
    if (partition != PARTITION_NONE && !splits_below &&
        mi_row + (mi_step >> 1) < cm->mi_rows &&
        mi_col + (mi_step >> 1) < cm->mi_cols) {
      *(get_sb_partitioning(x, bsize)) = bsize;
      rd_pick_sb_modes(cpi, tile, mi_row, mi_col, &none_rate, &none_dist, bsize,
                       get_block_context(x, bsize), INT64_MAX);

      pl = partition_plane_context(xd, mi_row, mi_col, bsize);

      if (none_rate < INT_MAX) {
        none_rate += x->partition_cost[pl][PARTITION_NONE];
        none_rd = RDCOST(x->rdmult, x->rddiv, none_rate, none_dist);
      }

      restore_context(cpi, mi_row, mi_col, a, l, sa, sl, bsize);
      mi_8x8[0]->mbmi.sb_type = bs_type;
      *(get_sb_partitioning(x, bsize)) = subsize;
    }
  }

  switch (partition) {
    case PARTITION_NONE:
      rd_pick_sb_modes(cpi, tile, mi_row, mi_col, &last_part_rate,
                       &last_part_dist, bsize,
                       get_block_context(x, bsize), INT64_MAX);
      break;
    case PARTITION_HORZ:
      *get_sb_index(x, subsize) = 0;
      rd_pick_sb_modes(cpi, tile, mi_row, mi_col, &last_part_rate,
                       &last_part_dist, subsize,
                       get_block_context(x, subsize), INT64_MAX);
      if (last_part_rate != INT_MAX &&
          bsize >= BLOCK_8X8 && mi_row + (mi_step >> 1) < cm->mi_rows) {
        int rt = 0;
        int64_t dt = 0;
        update_state(cpi, get_block_context(x, subsize), mi_row, mi_col,
                     subsize, 0);
        encode_superblock(cpi, tp, 0, mi_row, mi_col, subsize);
        *get_sb_index(x, subsize) = 1;
        rd_pick_sb_modes(cpi, tile, mi_row + (mi_step >> 1), mi_col, &rt, &dt,
                         subsize, get_block_context(x, subsize), INT64_MAX);
        if (rt == INT_MAX || dt == INT64_MAX) {
          last_part_rate = INT_MAX;
          last_part_dist = INT64_MAX;
          break;
        }

        last_part_rate += rt;
        last_part_dist += dt;
      }
      break;
    case PARTITION_VERT:
      *get_sb_index(x, subsize) = 0;
      rd_pick_sb_modes(cpi, tile, mi_row, mi_col, &last_part_rate,
                       &last_part_dist, subsize,
                       get_block_context(x, subsize), INT64_MAX);
      if (last_part_rate != INT_MAX &&
          bsize >= BLOCK_8X8 && mi_col + (mi_step >> 1) < cm->mi_cols) {
        int rt = 0;
        int64_t dt = 0;
        update_state(cpi, get_block_context(x, subsize), mi_row, mi_col,
                     subsize, 0);
        encode_superblock(cpi, tp, 0, mi_row, mi_col, subsize);
        *get_sb_index(x, subsize) = 1;
        rd_pick_sb_modes(cpi, tile, mi_row, mi_col + (mi_step >> 1), &rt, &dt,
                         subsize, get_block_context(x, subsize), INT64_MAX);
        if (rt == INT_MAX || dt == INT64_MAX) {
          last_part_rate = INT_MAX;
          last_part_dist = INT64_MAX;
          break;
        }
        last_part_rate += rt;
        last_part_dist += dt;
      }
      break;
    case PARTITION_SPLIT:
      // Split partition.
      last_part_rate = 0;
      last_part_dist = 0;
      for (i = 0; i < 4; i++) {
        int x_idx = (i & 1) * (mi_step >> 1);
        int y_idx = (i >> 1) * (mi_step >> 1);
        int jj = i >> 1, ii = i & 0x01;
        int rt;
        int64_t dt;

        if ((mi_row + y_idx >= cm->mi_rows) || (mi_col + x_idx >= cm->mi_cols))
          continue;

        *get_sb_index(x, subsize) = i;

        rd_use_partition(cpi, tile, mi_8x8 + jj * bss * mis + ii * bss, tp,
                         mi_row + y_idx, mi_col + x_idx, subsize, &rt, &dt,
                         i != 3);
        if (rt == INT_MAX || dt == INT64_MAX) {
          last_part_rate = INT_MAX;
          last_part_dist = INT64_MAX;
          break;
        }
        last_part_rate += rt;
        last_part_dist += dt;
      }
      break;
    default:
      assert(0);
  }

  pl = partition_plane_context(xd, mi_row, mi_col, bsize);
  if (last_part_rate < INT_MAX) {
    last_part_rate += x->partition_cost[pl][partition];
    last_part_rd = RDCOST(x->rdmult, x->rddiv, last_part_rate, last_part_dist);
  }

  if (do_partition_search
      && cpi->sf.adjust_partitioning_from_last_frame
      && cpi->sf.partition_search_type == SEARCH_PARTITION
      && partition != PARTITION_SPLIT && bsize > BLOCK_8X8
      && (mi_row + mi_step < cm->mi_rows ||
          mi_row + (mi_step >> 1) == cm->mi_rows)
      && (mi_col + mi_step < cm->mi_cols ||
          mi_col + (mi_step >> 1) == cm->mi_cols)) {
    BLOCK_SIZE split_subsize = get_subsize(bsize, PARTITION_SPLIT);
    chosen_rate = 0;
    chosen_dist = 0;
    restore_context(cpi, mi_row, mi_col, a, l, sa, sl, bsize);

    // Split partition.
    for (i = 0; i < 4; i++) {
      int x_idx = (i & 1) * (mi_step >> 1);
      int y_idx = (i >> 1) * (mi_step >> 1);
      int rt = 0;
      int64_t dt = 0;
      ENTROPY_CONTEXT l[16 * MAX_MB_PLANE], a[16 * MAX_MB_PLANE];
      PARTITION_CONTEXT sl[8], sa[8];

      if ((mi_row + y_idx >= cm->mi_rows) || (mi_col + x_idx >= cm->mi_cols))
        continue;

      *get_sb_index(x, split_subsize) = i;
      *get_sb_partitioning(x, bsize) = split_subsize;
      *get_sb_partitioning(x, split_subsize) = split_subsize;

      save_context(cpi, mi_row, mi_col, a, l, sa, sl, bsize);

      rd_pick_sb_modes(cpi, tile, mi_row + y_idx, mi_col + x_idx, &rt, &dt,
                       split_subsize, get_block_context(x, split_subsize),
                       INT64_MAX);

      restore_context(cpi, mi_row, mi_col, a, l, sa, sl, bsize);

      if (rt == INT_MAX || dt == INT64_MAX) {
        chosen_rate = INT_MAX;
        chosen_dist = INT64_MAX;
        break;
      }

      chosen_rate += rt;
      chosen_dist += dt;

      if (i != 3)
        encode_sb(cpi, tile, tp,  mi_row + y_idx, mi_col + x_idx, 0,
                  split_subsize);

      pl = partition_plane_context(xd, mi_row + y_idx, mi_col + x_idx,
                                   split_subsize);
      chosen_rate += x->partition_cost[pl][PARTITION_NONE];
    }
    pl = partition_plane_context(xd, mi_row, mi_col, bsize);
    if (chosen_rate < INT_MAX) {
      chosen_rate += x->partition_cost[pl][PARTITION_SPLIT];
      chosen_rd = RDCOST(x->rdmult, x->rddiv, chosen_rate, chosen_dist);
    }
  }

  // If last_part is better set the partitioning to that...
  if (last_part_rd < chosen_rd) {
    mi_8x8[0]->mbmi.sb_type = bsize;
    if (bsize >= BLOCK_8X8)
      *(get_sb_partitioning(x, bsize)) = subsize;
    chosen_rate = last_part_rate;
    chosen_dist = last_part_dist;
    chosen_rd = last_part_rd;
  }
  // If none was better set the partitioning to that...
  if (none_rd < chosen_rd) {
    if (bsize >= BLOCK_8X8)
      *(get_sb_partitioning(x, bsize)) = bsize;
    chosen_rate = none_rate;
    chosen_dist = none_dist;
  }

  restore_context(cpi, mi_row, mi_col, a, l, sa, sl, bsize);

  // We must have chosen a partitioning and encoding or we'll fail later on.
  // No other opportunities for success.
  if ( bsize == BLOCK_64X64)
    assert(chosen_rate < INT_MAX && chosen_dist < INT64_MAX);

  if (do_recon) {
    int output_enabled = (bsize == BLOCK_64X64);

    // Check the projected output rate for this SB against it's target
    // and and if necessary apply a Q delta using segmentation to get
    // closer to the target.
    if ((cpi->oxcf.aq_mode == COMPLEXITY_AQ) && cm->seg.update_map) {
      vp9_select_in_frame_q_segment(cpi, mi_row, mi_col,
                                    output_enabled, chosen_rate);
    }

    if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ)
      vp9_cyclic_refresh_set_rate_and_dist_sb(cpi->cyclic_refresh,
                                              chosen_rate, chosen_dist);