vp9_encodeframe.c

                           cm->uv_dc_delta_q == 0 &&
                           cm->uv_ac_delta_q == 0;

  cm->tx_mode = select_tx_mode(cpi);

  cpi->mb.fwd_txm4x4 = cpi->mb.e_mbd.lossless ? vp9_fwht4x4 : vp9_fdct4x4;
  cpi->mb.itxm_add = cpi->mb.e_mbd.lossless ? vp9_iwht4x4_add : vp9_idct4x4_add;

  if (cpi->mb.e_mbd.lossless) {
    cpi->mb.optimize = 0;
    cpi->common.lf.filter_level = 0;
    cpi->zbin_mode_boost_enabled = 0;
  }

  vp9_frame_init_quantizer(cpi);

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

  if (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->pc_root->none;

    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);

    if (sf->partition_search_type == SOURCE_VAR_BASED_PARTITION &&
        cm->current_video_frame > 0) {
      int check_freq = sf->search_type_check_frequency;

      if ((cm->current_video_frame - 1) % check_freq == 0) {
        cpi->use_large_partition_rate = 0;
      }

      if ((cm->current_video_frame - 1) % check_freq == 1) {
        const int mbs_in_b32x32 = 1 << ((b_width_log2_lookup[BLOCK_32X32] -
                                  b_width_log2_lookup[BLOCK_16X16]) +
                                  (b_height_log2_lookup[BLOCK_32X32] -
                                  b_height_log2_lookup[BLOCK_16X16]));
        cpi->use_large_partition_rate = cpi->use_large_partition_rate * 100 *
                                        mbs_in_b32x32 / cm->MBs;
      }

      if ((cm->current_video_frame - 1) % check_freq >= 1) {
        if (cpi->use_large_partition_rate < 15)
          sf->partition_search_type = FIXED_PARTITION;
      }
    }
  }

  {
    struct vpx_usec_timer emr_timer;
    vpx_usec_timer_start(&emr_timer);

    encode_tiles(cpi);

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

  sf->skip_encode_frame = sf->skip_encode_sb ? get_skip_encode_frame(cm) : 0;

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

static INTERP_FILTER get_interp_filter(
    const int64_t threshes[SWITCHABLE_FILTER_CONTEXTS], int is_alt_ref) {
  if (!is_alt_ref &&
      threshes[EIGHTTAP_SMOOTH] > threshes[EIGHTTAP] &&
      threshes[EIGHTTAP_SMOOTH] > threshes[EIGHTTAP_SHARP] &&
      threshes[EIGHTTAP_SMOOTH] > threshes[SWITCHABLE - 1]) {
    return EIGHTTAP_SMOOTH;
  } else if (threshes[EIGHTTAP_SHARP] > threshes[EIGHTTAP] &&
             threshes[EIGHTTAP_SHARP] > threshes[SWITCHABLE - 1]) {
    return EIGHTTAP_SHARP;
  } else if (threshes[EIGHTTAP] > threshes[SWITCHABLE - 1]) {
    return EIGHTTAP;
  } else {
    return SWITCHABLE;
  }
}

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

  // 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;

    // 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);
    int64_t *const mode_thrs = rd_opt->prediction_type_threshes[frame_type];
    int64_t *const filter_thrs = rd_opt->filter_threshes[frame_type];
    int *const tx_thrs = rd_opt->tx_select_threshes[frame_type];
    const int is_alt_ref = frame_type == ALTREF_FRAME;

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

    if (cm->interp_filter == SWITCHABLE)
      cm->interp_filter = get_interp_filter(filter_thrs, is_alt_ref);

    encode_frame_internal(cpi);

    for (i = 0; i < REFERENCE_MODES; ++i)
      mode_thrs[i] = (mode_thrs[i] + rd_opt->comp_pred_diff[i] / cm->MBs) / 2;

    for (i = 0; i < SWITCHABLE_FILTER_CONTEXTS; ++i)
      filter_thrs[i] = (filter_thrs[i] + rd_opt->filter_diff[i] / cm->MBs) / 2;

    for (i = 0; i < TX_MODES; ++i) {
      int64_t pd = rd_opt->tx_select_diff[i];
      if (i == TX_MODE_SELECT)
        pd -= RDCOST(cpi->mb.rdmult, cpi->mb.rddiv, 2048 * (TX_SIZES - 1), 0);
      tx_thrs[i] = (tx_thrs[i] + (int)(pd / cm->MBs)) / 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 {
    cm->reference_mode = SINGLE_REFERENCE;
    cm->interp_filter = SWITCHABLE;
    encode_frame_internal(cpi);
  }
}

static void sum_intra_stats(FRAME_COUNTS *counts, const MODE_INFO *mi) {
  const PREDICTION_MODE y_mode = mi->mbmi.mode;
  const 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];
}

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,
                              PICK_MODE_CONTEXT *ctx) {
  VP9_COMMON *const cm = &cpi->common;
  MACROBLOCK *const x = &cpi->mb;
  MACROBLOCKD *const xd = &x->e_mbd;
  MODE_INFO **mi_8x8 = xd->mi;
  MODE_INFO *mi = mi_8x8[0];
  MB_MODE_INFO *mbmi = &mi->mbmi;
  unsigned int segment_id = mbmi->segment_id;
  const int mis = cm->mi_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.allow_skip_recode;

  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;

  set_ref_ptrs(cm, xd, mbmi->ref_frame[0], mbmi->ref_frame[1]);

  // 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 &&
          !vp9_segfeature_active(&cm->seg, mbmi->segment_id, SEG_LVL_SKIP))
        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;
    }
  }
}