vp9_encodeframe.c

                    *(get_sb_partitioning(x, bsize)));

  if (best_rate < INT_MAX && best_dist < INT64_MAX && 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) {
      select_in_frame_q_segment(cpi, mi_row, mi_col, output_enabled, best_rate);
    }
    if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ) {
      cpi->cyclic_refresh.projected_rate_sb = best_rate;
      cpi->cyclic_refresh.projected_dist_sb = best_dist;
    }

    encode_sb(cpi, tile, tp, mi_row, mi_col, output_enabled, bsize);
  }

  if (bsize == BLOCK_64X64) {
    assert(tp_orig < *tp);
    assert(best_rate < INT_MAX);
    assert(best_dist < INT64_MAX);
  } else {
    assert(tp_orig == *tp);
  }
}

static void nonrd_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 output_enabled,
                                int *totrate, int64_t *totdist) {
  VP9_COMMON *const cm = &cpi->common;
  MACROBLOCK *const x = &cpi->mb;
  const int bsl = b_width_log2(bsize), hbs = (1 << bsl) / 4;
  const int mis = cm->mode_info_stride;
  PARTITION_TYPE partition;
  BLOCK_SIZE subsize;
  int rate = INT_MAX;
  int64_t dist = INT64_MAX;

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

  if (bsize >= BLOCK_8X8) {
    subsize = mi_8x8[0]->mbmi.sb_type;
  } else {
    subsize = BLOCK_4X4;
  }

  partition = partition_lookup[bsl][subsize];

  switch (partition) {
    case PARTITION_NONE:
      nonrd_pick_sb_modes(cpi, tile, mi_row, mi_col, totrate, totdist, subsize);
      break;
    case PARTITION_VERT:
      *get_sb_index(x, subsize) = 0;
      nonrd_pick_sb_modes(cpi, tile, mi_row, mi_col, totrate, totdist, subsize);
      if (mi_col + hbs < cm->mi_cols) {
        *get_sb_index(x, subsize) = 1;
        nonrd_pick_sb_modes(cpi, tile, mi_row, mi_col + hbs,
                            &rate, &dist, subsize);
        if (rate != INT_MAX && dist != INT64_MAX &&
            *totrate != INT_MAX && *totdist != INT64_MAX) {
          *totrate += rate;
          *totdist += dist;
        }
      }
      break;
    case PARTITION_HORZ:
      *get_sb_index(x, subsize) = 0;
      nonrd_pick_sb_modes(cpi, tile, mi_row, mi_col, totrate, totdist, subsize);
      if (mi_row + hbs < cm->mi_rows) {
        *get_sb_index(x, subsize) = 1;
        nonrd_pick_sb_modes(cpi, tile, mi_row + hbs, mi_col,
                            &rate, &dist, subsize);
        if (rate != INT_MAX && dist != INT64_MAX &&
            *totrate != INT_MAX && *totdist != INT64_MAX) {
          *totrate += rate;
          *totdist += dist;
        }
      }
      break;
    case PARTITION_SPLIT:
      subsize = get_subsize(bsize, PARTITION_SPLIT);
      *get_sb_index(x, subsize) = 0;
      nonrd_use_partition(cpi, tile, mi_8x8, tp, mi_row, mi_col,
                          subsize, output_enabled, totrate, totdist);
      *get_sb_index(x, subsize) = 1;
      nonrd_use_partition(cpi, tile, mi_8x8 + hbs, tp,
                          mi_row, mi_col + hbs, subsize, output_enabled,
                          &rate, &dist);
      if (rate != INT_MAX && dist != INT64_MAX &&
          *totrate != INT_MAX && *totdist != INT64_MAX) {
        *totrate += rate;
        *totdist += dist;
      }
      *get_sb_index(x, subsize) = 2;
      nonrd_use_partition(cpi, tile, mi_8x8 + hbs * mis, tp,
                          mi_row + hbs, mi_col, subsize, output_enabled,
                          &rate, &dist);
      if (rate != INT_MAX && dist != INT64_MAX &&
          *totrate != INT_MAX && *totdist != INT64_MAX) {
        *totrate += rate;
        *totdist += dist;
      }
      *get_sb_index(x, subsize) = 3;
      nonrd_use_partition(cpi, tile, mi_8x8 + hbs * mis + hbs, tp,
                          mi_row + hbs, mi_col + hbs, subsize, output_enabled,
                          &rate, &dist);
      if (rate != INT_MAX && dist != INT64_MAX &&
          *totrate != INT_MAX && *totdist != INT64_MAX) {
        *totrate += rate;
        *totdist += dist;
      }
      break;
    default:
      assert("Invalid partition type.");
  }

  if (bsize == BLOCK_64X64 && output_enabled) {
    if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ) {
      cpi->cyclic_refresh.projected_rate_sb = *totrate;
      cpi->cyclic_refresh.projected_dist_sb = *totdist;
    }
    encode_sb_rt(cpi, tile, tp, mi_row, mi_col, 1, bsize);
  }
}

static void encode_nonrd_sb_row(VP9_COMP *cpi, const TileInfo *const tile,
                                int mi_row, TOKENEXTRA **tp) {
  VP9_COMMON *cm = &cpi->common;
  MACROBLOCKD *xd = &cpi->mb.e_mbd;
  int mi_col;

  // Initialize the left context for the new SB row
  vpx_memset(&cpi->left_context, 0, sizeof(cpi->left_context));
  vpx_memset(xd->left_seg_context, 0, sizeof(xd->left_seg_context));

  // Code each SB in the row
  for (mi_col = tile->mi_col_start; mi_col < tile->mi_col_end;
       mi_col += MI_BLOCK_SIZE) {
    int dummy_rate = 0;
    int64_t dummy_dist = 0;
    const int idx_str = cm->mode_info_stride * mi_row + mi_col;
    MODE_INFO **mi_8x8 = cm->mi_grid_visible + idx_str;
    MODE_INFO **prev_mi_8x8 = cm->prev_mi_grid_visible + idx_str;

    BLOCK_SIZE bsize = cpi->sf.partition_search_type == FIXED_PARTITION ?
        cpi->sf.always_this_block_size :
        get_nonrd_var_based_fixed_partition(cpi, mi_row, mi_col);

    cpi->mb.source_variance = UINT_MAX;

    // Set the partition type of the 64X64 block
    switch (cpi->sf.partition_search_type) {
      case VAR_BASED_PARTITION:
        choose_partitioning(cpi, tile, mi_row, mi_col);
        nonrd_use_partition(cpi, tile, mi_8x8, tp, mi_row, mi_col, BLOCK_64X64,
                            1, &dummy_rate, &dummy_dist);
        break;
      case VAR_BASED_FIXED_PARTITION:
      case FIXED_PARTITION:
        set_fixed_partitioning(cpi, tile, mi_8x8, mi_row, mi_col, bsize);
        nonrd_use_partition(cpi, tile, mi_8x8, tp, mi_row, mi_col, BLOCK_64X64,
                            1, &dummy_rate, &dummy_dist);
        break;
      case REFERENCE_PARTITION:
        if (cpi->sf.partition_check) {
          vp9_zero(cpi->mb.pred_mv);
          nonrd_pick_partition(cpi, tile, tp, mi_row, mi_col, BLOCK_64X64,
                               &dummy_rate, &dummy_dist, 1, INT64_MAX);
        } else {
          if (!sb_has_motion(cm, prev_mi_8x8))
            copy_partitioning(cm, mi_8x8, prev_mi_8x8);
          else
            set_fixed_partitioning(cpi, tile, mi_8x8, mi_row, mi_col, bsize);

          nonrd_use_partition(cpi, tile, mi_8x8, tp, mi_row, mi_col,
                              BLOCK_64X64, 1, &dummy_rate, &dummy_dist);
        }
        break;
      default:
        assert(0);
    }
  }
}
// end RTC play code

static void encode_frame_internal(VP9_COMP *cpi) {
  int mi_row;
  MACROBLOCK *const x = &cpi->mb;
  VP9_COMMON *const cm = &cpi->common;
  MACROBLOCKD *const xd = &x->e_mbd;

//  fprintf(stderr, "encode_frame_internal frame %d (%d) type %d\n",
//           cpi->common.current_video_frame, cpi->common.show_frame,
//           cm->frame_type);

  vp9_zero(cm->counts.switchable_interp);
  vp9_zero(cpi->tx_stepdown_count);

  xd->mi_8x8 = cm->mi_grid_visible;
  // required for vp9_frame_init_quantizer
  xd->mi_8x8[0] = cm->mi;

  vp9_zero(cm->counts.mv);
  vp9_zero(cpi->coef_counts);
  vp9_zero(cm->counts.eob_branch);

  // Set frame level transform size use case
  cm->tx_mode = select_tx_mode(cpi);

  cpi->mb.e_mbd.lossless = cm->base_qindex == 0 && cm->y_dc_delta_q == 0
      && cm->uv_dc_delta_q == 0 && cm->uv_ac_delta_q == 0;
  switch_lossless_mode(cpi, cpi->mb.e_mbd.lossless);

  vp9_frame_init_quantizer(cpi);

  vp9_initialize_rd_consts(cpi);
  vp9_initialize_me_consts(cpi, cm->base_qindex);

  if (cpi->oxcf.tuning == VP8_TUNE_SSIM) {
    // Initialize encode frame context.
    init_encode_frame_mb_context(cpi);

    // Build a frame level activity map
    build_activity_map(cpi);
  }

  // Re-initialize encode frame context.
  init_encode_frame_mb_context(cpi);

  vp9_zero(cpi->rd_comp_pred_diff);
  vp9_zero(cpi->rd_filter_diff);
  vp9_zero(cpi->rd_tx_select_diff);
  vp9_zero(cpi->rd_tx_select_threshes);

  set_prev_mi(cm);

  if (cpi->sf.use_nonrd_pick_mode) {
    // Initialize internal buffer pointers for rtc coding, where non-RD
    // mode decision is used and hence no buffer pointer swap needed.
    int i;
    struct macroblock_plane *const p = x->plane;
    struct macroblockd_plane *const pd = xd->plane;
    PICK_MODE_CONTEXT *ctx = &cpi->mb.sb64_context;

    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];
    }
    vp9_zero(x->zcoeff_blk);
  }

  {
    struct vpx_usec_timer emr_timer;
    vpx_usec_timer_start(&emr_timer);

    {
      // Take tiles into account and give start/end MB
      int tile_col, tile_row;
      TOKENEXTRA *tp = cpi->tok;
      const int tile_cols = 1 << cm->log2_tile_cols;
      const int tile_rows = 1 << cm->log2_tile_rows;

      for (tile_row = 0; tile_row < tile_rows; tile_row++) {
        for (tile_col = 0; tile_col < tile_cols; tile_col++) {
          TileInfo tile;
          TOKENEXTRA *tp_old = tp;

          // For each row of SBs in the frame
          vp9_tile_init(&tile, cm, tile_row, tile_col);
          for (mi_row = tile.mi_row_start;
               mi_row < tile.mi_row_end; mi_row += MI_BLOCK_SIZE) {
            if (cpi->sf.use_nonrd_pick_mode && cm->frame_type != KEY_FRAME)
              encode_nonrd_sb_row(cpi, &tile, mi_row, &tp);
            else
              encode_rd_sb_row(cpi, &tile, mi_row, &tp);
          }
          cpi->tok_count[tile_row][tile_col] = (unsigned int)(tp - tp_old);
          assert(tp - cpi->tok <= get_token_alloc(cm->mb_rows, cm->mb_cols));
        }
      }
    }

    vpx_usec_timer_mark(&emr_timer);
    cpi->time_encode_sb_row += vpx_usec_timer_elapsed(&emr_timer);
  }

  if (cpi->sf.skip_encode_sb) {
    int j;
    unsigned int intra_count = 0, inter_count = 0;
    for (j = 0; j < INTRA_INTER_CONTEXTS; ++j) {
      intra_count += cm->counts.intra_inter[j][0];
      inter_count += cm->counts.intra_inter[j][1];
    }
    cpi->sf.skip_encode_frame = (intra_count << 2) < inter_count &&
                                cm->frame_type != KEY_FRAME &&
                                cm->show_frame;
  } else {
    cpi->sf.skip_encode_frame = 0;
  }

#if 0
  // Keep record of the total distortion this time around for future use
  cpi->last_frame_distortion = cpi->frame_distortion;
#endif
}

void vp9_encode_frame(VP9_COMP *cpi) {
  VP9_COMMON *const cm = &cpi->common;

  // In the longer term the encoder should be generalized to match the
  // decoder such that we allow compound where one of the 3 buffers has a
  // different sign bias and that buffer is then the fixed ref. However, this
  // requires further work in the rd loop. For now the only supported encoder
  // side behavior is where the ALT ref buffer has opposite sign bias to
  // the other two.
  if (!frame_is_intra_only(cm)) {
    if ((cm->ref_frame_sign_bias[ALTREF_FRAME] ==
             cm->ref_frame_sign_bias[GOLDEN_FRAME]) ||
        (cm->ref_frame_sign_bias[ALTREF_FRAME] ==
             cm->ref_frame_sign_bias[LAST_FRAME])) {
      cm->allow_comp_inter_inter = 0;
    } else {
      cm->allow_comp_inter_inter = 1;
      cm->comp_fixed_ref = ALTREF_FRAME;
      cm->comp_var_ref[0] = LAST_FRAME;
      cm->comp_var_ref[1] = GOLDEN_FRAME;
    }
  }

  if (cpi->sf.frame_parameter_update) {
    int i;
    REFERENCE_MODE reference_mode;
    /*
     * This code does a single RD pass over the whole frame assuming
     * either compound, single or hybrid prediction as per whatever has
     * worked best for that type of frame in the past.
     * It also predicts whether another coding mode would have worked
     * better that this coding mode. If that is the case, it remembers
     * that for subsequent frames.
     * It does the same analysis for transform size selection also.
     */
    const MV_REFERENCE_FRAME frame_type = get_frame_type(cpi);
    const int64_t *mode_thresh = cpi->rd_prediction_type_threshes[frame_type];
    const int64_t *filter_thresh = cpi->rd_filter_threshes[frame_type];

    /* prediction (compound, single or hybrid) mode selection */
    if (frame_type == 3 || !cm->allow_comp_inter_inter)
      reference_mode = SINGLE_REFERENCE;
    else if (mode_thresh[COMPOUND_REFERENCE] > mode_thresh[SINGLE_REFERENCE] &&
             mode_thresh[COMPOUND_REFERENCE] >
                 mode_thresh[REFERENCE_MODE_SELECT] &&
             check_dual_ref_flags(cpi) &&
             cpi->static_mb_pct == 100)
      reference_mode = COMPOUND_REFERENCE;
    else if (mode_thresh[SINGLE_REFERENCE] > mode_thresh[REFERENCE_MODE_SELECT])
      reference_mode = SINGLE_REFERENCE;
    else
      reference_mode = REFERENCE_MODE_SELECT;

    if (cm->interp_filter == SWITCHABLE) {
      if (frame_type != ALTREF_FRAME &&
          filter_thresh[EIGHTTAP_SMOOTH] > filter_thresh[EIGHTTAP] &&
          filter_thresh[EIGHTTAP_SMOOTH] > filter_thresh[EIGHTTAP_SHARP] &&
          filter_thresh[EIGHTTAP_SMOOTH] > filter_thresh[SWITCHABLE - 1]) {
        cm->interp_filter = EIGHTTAP_SMOOTH;
      } else if (filter_thresh[EIGHTTAP_SHARP] > filter_thresh[EIGHTTAP] &&
          filter_thresh[EIGHTTAP_SHARP] > filter_thresh[SWITCHABLE - 1]) {
        cm->interp_filter = EIGHTTAP_SHARP;
      } else if (filter_thresh[EIGHTTAP] > filter_thresh[SWITCHABLE - 1]) {
        cm->interp_filter = EIGHTTAP;
      }
    }

    cpi->mb.e_mbd.lossless = cpi->oxcf.lossless;
    cm->reference_mode = reference_mode;

    encode_frame_internal(cpi);

    for (i = 0; i < REFERENCE_MODES; ++i) {
      const int diff = (int) (cpi->rd_comp_pred_diff[i] / cm->MBs);
      cpi->rd_prediction_type_threshes[frame_type][i] += diff;
      cpi->rd_prediction_type_threshes[frame_type][i] >>= 1;
    }

    for (i = 0; i < SWITCHABLE_FILTER_CONTEXTS; i++) {
      const int64_t diff = cpi->rd_filter_diff[i] / cm->MBs;
      cpi->rd_filter_threshes[frame_type][i] =
          (cpi->rd_filter_threshes[frame_type][i] + diff) / 2;
    }

    for (i = 0; i < TX_MODES; ++i) {
      int64_t pd = cpi->rd_tx_select_diff[i];
      int diff;
      if (i == TX_MODE_SELECT)
        pd -= RDCOST(cpi->mb.rdmult, cpi->mb.rddiv, 2048 * (TX_SIZES - 1), 0);
      diff = (int) (pd / cm->MBs);
      cpi->rd_tx_select_threshes[frame_type][i] += diff;
      cpi->rd_tx_select_threshes[frame_type][i] /= 2;
    }

    if (cm->reference_mode == REFERENCE_MODE_SELECT) {
      int single_count_zero = 0;
      int comp_count_zero = 0;

      for (i = 0; i < COMP_INTER_CONTEXTS; i++) {
        single_count_zero += cm->counts.comp_inter[i][0];
        comp_count_zero += cm->counts.comp_inter[i][1];
      }

      if (comp_count_zero == 0) {
        cm->reference_mode = SINGLE_REFERENCE;
        vp9_zero(cm->counts.comp_inter);
      } else if (single_count_zero == 0) {
        cm->reference_mode = COMPOUND_REFERENCE;
        vp9_zero(cm->counts.comp_inter);
      }
    }

    if (cm->tx_mode == TX_MODE_SELECT) {
      int count4x4 = 0;
      int count8x8_lp = 0, count8x8_8x8p = 0;
      int count16x16_16x16p = 0, count16x16_lp = 0;
      int count32x32 = 0;

      for (i = 0; i < TX_SIZE_CONTEXTS; ++i) {
        count4x4 += cm->counts.tx.p32x32[i][TX_4X4];
        count4x4 += cm->counts.tx.p16x16[i][TX_4X4];
        count4x4 += cm->counts.tx.p8x8[i][TX_4X4];

        count8x8_lp += cm->counts.tx.p32x32[i][TX_8X8];
        count8x8_lp += cm->counts.tx.p16x16[i][TX_8X8];
        count8x8_8x8p += cm->counts.tx.p8x8[i][TX_8X8];

        count16x16_16x16p += cm->counts.tx.p16x16[i][TX_16X16];
        count16x16_lp += cm->counts.tx.p32x32[i][TX_16X16];
        count32x32 += cm->counts.tx.p32x32[i][TX_32X32];
      }

      if (count4x4 == 0 && count16x16_lp == 0 && count16x16_16x16p == 0 &&
          count32x32 == 0) {
        cm->tx_mode = ALLOW_8X8;
        reset_skip_txfm_size(cm, TX_8X8);
      } else if (count8x8_8x8p == 0 && count16x16_16x16p == 0 &&
                 count8x8_lp == 0 && count16x16_lp == 0 && count32x32 == 0) {
        cm->tx_mode = ONLY_4X4;
        reset_skip_txfm_size(cm, TX_4X4);
      } else if (count8x8_lp == 0 && count16x16_lp == 0 && count4x4 == 0) {
        cm->tx_mode = ALLOW_32X32;
      } else if (count32x32 == 0 && count8x8_lp == 0 && count4x4 == 0) {
        cm->tx_mode = ALLOW_16X16;
        reset_skip_txfm_size(cm, TX_16X16);
      }
    }
  } else {
    cpi->mb.e_mbd.lossless = cpi->oxcf.lossless;
    cm->reference_mode = SINGLE_REFERENCE;
    // Force the usage of the BILINEAR interp_filter.
    cm->interp_filter = BILINEAR;
    encode_frame_internal(cpi);
  }
}

static void sum_intra_stats(FRAME_COUNTS *counts, const MODE_INFO *mi) {
  const MB_PREDICTION_MODE y_mode = mi->mbmi.mode;
  const MB_PREDICTION_MODE uv_mode = mi->mbmi.uv_mode;
  const BLOCK_SIZE bsize = mi->mbmi.sb_type;

  if (bsize < BLOCK_8X8) {
    int idx, idy;
    const int num_4x4_w = num_4x4_blocks_wide_lookup[bsize];
    const int num_4x4_h = num_4x4_blocks_high_lookup[bsize];
    for (idy = 0; idy < 2; idy += num_4x4_h)
      for (idx = 0; idx < 2; idx += num_4x4_w)
        ++counts->y_mode[0][mi->bmi[idy * 2 + idx].as_mode];
  } else {
    ++counts->y_mode[size_group_lookup[bsize]][y_mode];
  }

  ++counts->uv_mode[y_mode][uv_mode];
}

// Experimental stub function to create a per MB zbin adjustment based on
// some previously calculated measure of MB activity.
static void adjust_act_zbin(VP9_COMP *cpi, MACROBLOCK *x) {
#if USE_ACT_INDEX
  x->act_zbin_adj = *(x->mb_activity_ptr);
#else
  // Apply the masking to the RD multiplier.
  const int64_t act = *(x->mb_activity_ptr);
  const int64_t a = act + 4 * cpi->activity_avg;
  const int64_t b = 4 * act + cpi->activity_avg;

  if (act > cpi->activity_avg)
    x->act_zbin_adj = (int) (((int64_t) b + (a >> 1)) / a) - 1;
  else
    x->act_zbin_adj = 1 - (int) (((int64_t) a + (b >> 1)) / b);
#endif
}

static int get_zbin_mode_boost(const MB_MODE_INFO *mbmi, int enabled) {
  if (enabled) {
    if (is_inter_block(mbmi)) {
      if (mbmi->mode == ZEROMV) {
        return mbmi->ref_frame[0] != LAST_FRAME ? GF_ZEROMV_ZBIN_BOOST
                                                : LF_ZEROMV_ZBIN_BOOST;
      } else {
        return mbmi->sb_type < BLOCK_8X8 ? SPLIT_MV_ZBIN_BOOST
                                         : MV_ZBIN_BOOST;
      }
    } else {
      return INTRA_ZBIN_BOOST;
    }
  } else {
    return 0;
  }
}

static void encode_superblock(VP9_COMP *cpi, TOKENEXTRA **t, int output_enabled,
                              int mi_row, int mi_col, BLOCK_SIZE bsize) {
  VP9_COMMON *const cm = &cpi->common;
  MACROBLOCK *const x = &cpi->mb;
  MACROBLOCKD *const xd = &x->e_mbd;
  MODE_INFO **mi_8x8 = xd->mi_8x8;
  MODE_INFO *mi = mi_8x8[0];
  MB_MODE_INFO *mbmi = &mi->mbmi;
  PICK_MODE_CONTEXT *ctx = get_block_context(x, bsize);
  unsigned int segment_id = mbmi->segment_id;
  const int mis = cm->mode_info_stride;
  const int mi_width = num_8x8_blocks_wide_lookup[bsize];
  const int mi_height = num_8x8_blocks_high_lookup[bsize];

  x->skip_recode = !x->select_txfm_size && mbmi->sb_type >= BLOCK_8X8 &&
                   (cpi->oxcf.aq_mode != COMPLEXITY_AQ &&
                    cpi->oxcf.aq_mode != CYCLIC_REFRESH_AQ) &&
                   !cpi->sf.use_nonrd_pick_mode &&
                   !cpi->sf.use_uv_intra_rd_estimate &&
                   !cpi->sf.skip_encode_sb;

  x->skip_optimize = ctx->is_coded;
  ctx->is_coded = 1;
  x->use_lp32x32fdct = cpi->sf.use_lp32x32fdct;
  x->skip_encode = (!output_enabled && cpi->sf.skip_encode_frame &&
                    x->q_index < QIDX_SKIP_THRESH);

  if (x->skip_encode)
    return;

  if (cm->frame_type == KEY_FRAME) {
    if (cpi->oxcf.tuning == VP8_TUNE_SSIM) {
      adjust_act_zbin(cpi, x);
      vp9_update_zbin_extra(cpi, x);
    }
  } else {
    set_ref_ptrs(cm, xd, mbmi->ref_frame[0], mbmi->ref_frame[1]);
    xd->interp_kernel = vp9_get_interp_kernel(mbmi->interp_filter);

    if (cpi->oxcf.tuning == VP8_TUNE_SSIM) {
      // Adjust the zbin based on this MB rate.
      adjust_act_zbin(cpi, x);
    }

    // Experimental code. Special case for gf and arf zeromv modes.
    // Increase zbin size to suppress noise
    cpi->zbin_mode_boost = get_zbin_mode_boost(mbmi,
                                               cpi->zbin_mode_boost_enabled);
    vp9_update_zbin_extra(cpi, x);
  }

  if (!is_inter_block(mbmi)) {
    int plane;
    mbmi->skip = 1;
    for (plane = 0; plane < MAX_MB_PLANE; ++plane)
      vp9_encode_intra_block_plane(x, MAX(bsize, BLOCK_8X8), plane);
    if (output_enabled)
      sum_intra_stats(&cm->counts, mi);
    vp9_tokenize_sb(cpi, t, !output_enabled, MAX(bsize, BLOCK_8X8));
  } else {
    int ref;
    const int is_compound = has_second_ref(mbmi);
    for (ref = 0; ref < 1 + is_compound; ++ref) {
      YV12_BUFFER_CONFIG *cfg = get_ref_frame_buffer(cpi,
                                                     mbmi->ref_frame[ref]);
      vp9_setup_pre_planes(xd, ref, cfg, mi_row, mi_col,
                           &xd->block_refs[ref]->sf);
    }
    vp9_build_inter_predictors_sb(xd, mi_row, mi_col, MAX(bsize, BLOCK_8X8));

    if (!x->skip) {
      mbmi->skip = 1;
      vp9_encode_sb(x, MAX(bsize, BLOCK_8X8));
      vp9_tokenize_sb(cpi, t, !output_enabled, MAX(bsize, BLOCK_8X8));
    } else {
      mbmi->skip = 1;
      if (output_enabled)
        cm->counts.skip[vp9_get_skip_context(xd)][1]++;
      reset_skip_context(xd, MAX(bsize, BLOCK_8X8));
    }
  }

  if (output_enabled) {
    if (cm->tx_mode == TX_MODE_SELECT &&
        mbmi->sb_type >= BLOCK_8X8  &&
        !(is_inter_block(mbmi) &&
            (mbmi->skip ||
             vp9_segfeature_active(&cm->seg, segment_id, SEG_LVL_SKIP)))) {
      ++get_tx_counts(max_txsize_lookup[bsize], vp9_get_tx_size_context(xd),
                      &cm->counts.tx)[mbmi->tx_size];
    } else {
      int x, y;
      TX_SIZE tx_size;
      // The new intra coding scheme requires no change of transform size
      if (is_inter_block(&mi->mbmi)) {
        tx_size = MIN(tx_mode_to_biggest_tx_size[cm->tx_mode],
                      max_txsize_lookup[bsize]);
      } else {
        tx_size = (bsize >= BLOCK_8X8) ? mbmi->tx_size : TX_4X4;
      }

      for (y = 0; y < mi_height; y++)
        for (x = 0; x < mi_width; x++)
          if (mi_col + x < cm->mi_cols && mi_row + y < cm->mi_rows)
            mi_8x8[mis * y + x]->mbmi.tx_size = tx_size;
    }
  }
}