encodeframe.c

  // GF active flags data structure
  x->gf_active_ptr = (signed char *)cpi->gf_active_flags;

  // Activity map pointer
  x->mb_activity_ptr = cpi->mb_activity_map;

  x->act_zbin_adj = 0;
  cpi->seg0_idx = 0;
  vpx_memset(cpi->ref_pred_count, 0, sizeof(cpi->ref_pred_count));

  x->partition_info = x->pi;

  xd->mode_info_context = cm->mi;
  xd->mode_info_stride = cm->mode_info_stride;
  xd->prev_mode_info_context = cm->prev_mi;

  xd->frame_type = cm->frame_type;

  xd->frames_since_golden = cm->frames_since_golden;
  xd->frames_till_alt_ref_frame = cm->frames_till_alt_ref_frame;

  // reset intra mode contexts
  if (cm->frame_type == KEY_FRAME)
    vp8_init_mbmode_probs(cm);

  // Copy data over into macro block data structures.
  x->src = * cpi->Source;
  xd->pre = cm->yv12_fb[cm->lst_fb_idx];
  xd->dst = cm->yv12_fb[cm->new_fb_idx];

  // set up frame for intra coded blocks
  vp8_setup_intra_recon(&cm->yv12_fb[cm->new_fb_idx]);

  vp8_build_block_offsets(x);

  vp8_setup_block_dptrs(&x->e_mbd);

  vp8_setup_block_ptrs(x);

  xd->mode_info_context->mbmi.mode = DC_PRED;
  xd->mode_info_context->mbmi.uv_mode = DC_PRED;

  xd->left_context = &cm->left_context;

  vp8_zero(cpi->count_mb_ref_frame_usage)
  vp8_zero(cpi->bmode_count)
  vp8_zero(cpi->ymode_count)
  vp8_zero(cpi->i8x8_mode_count)
  vp8_zero(cpi->y_uv_mode_count)
  vp8_zero(cpi->sub_mv_ref_count)
  vp8_zero(cpi->mbsplit_count)
  vp8_zero(cpi->common.fc.mv_ref_ct)
  vp8_zero(cpi->common.fc.mv_ref_ct_a)
  // vp8_zero(cpi->uv_mode_count)

  x->mvc = cm->fc.mvc;
#if CONFIG_HIGH_PRECISION_MV
  x->mvc_hp = cm->fc.mvc_hp;
#endif

  vpx_memset(cm->above_context, 0,
             sizeof(ENTROPY_CONTEXT_PLANES) * cm->mb_cols);

  xd->fullpixel_mask = 0xffffffff;
  if (cm->full_pixel)
    xd->fullpixel_mask = 0xfffffff8;
}

static void encode_frame_internal(VP8_COMP *cpi) {
  int mb_row;
  MACROBLOCK *const x = & cpi->mb;
  VP8_COMMON *const cm = & cpi->common;
  MACROBLOCKD *const xd = & x->e_mbd;

  TOKENEXTRA *tp = cpi->tok;
  int totalrate;

  // Compute a modified set of reference frame probabilities to use when
  // prediction fails. These are based on the current general estimates for
  // this frame which may be updated with each iteration of the recode loop.
  compute_mod_refprobs(cm);

// debug output
#if DBG_PRNT_SEGMAP
  {
    FILE *statsfile;
    statsfile = fopen("segmap2.stt", "a");
    fprintf(statsfile, "\n");
    fclose(statsfile);
  }
#endif

  totalrate = 0;

  // Functions setup for all frame types so we can use MC in AltRef
  if (cm->mcomp_filter_type == SIXTAP) {
    xd->subpixel_predict        = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, sixtap4x4);
    xd->subpixel_predict8x4     = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, sixtap8x4);
    xd->subpixel_predict8x8     = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, sixtap8x8);
    xd->subpixel_predict16x16   = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, sixtap16x16);
    xd->subpixel_predict_avg    = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, sixtap_avg4x4);
    xd->subpixel_predict_avg8x8 = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, sixtap_avg8x8);
    xd->subpixel_predict_avg16x16 = SUBPIX_INVOKE(
                                      &cpi->common.rtcd.subpix, sixtap_avg16x16);
  }
#if CONFIG_ENHANCED_INTERP
  else if (cm->mcomp_filter_type == EIGHTTAP) {
    xd->subpixel_predict        = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap4x4);
    xd->subpixel_predict8x4     = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap8x4);
    xd->subpixel_predict8x8     = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap8x8);
    xd->subpixel_predict16x16   = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap16x16);
    xd->subpixel_predict_avg    = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap_avg4x4);
    xd->subpixel_predict_avg8x8 = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap_avg8x8);
    xd->subpixel_predict_avg16x16 = SUBPIX_INVOKE(
                                      &cpi->common.rtcd.subpix, eighttap_avg16x16);
  } else if (cm->mcomp_filter_type == EIGHTTAP_SHARP) {
    xd->subpixel_predict        = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap4x4_sharp);
    xd->subpixel_predict8x4     = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap8x4_sharp);
    xd->subpixel_predict8x8     = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap8x8_sharp);
    xd->subpixel_predict16x16   = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap16x16_sharp);
    xd->subpixel_predict_avg    = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap_avg4x4_sharp);
    xd->subpixel_predict_avg8x8 = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, eighttap_avg8x8_sharp);
    xd->subpixel_predict_avg16x16 = SUBPIX_INVOKE(
                                      &cpi->common.rtcd.subpix, eighttap_avg16x16_sharp);
  }
#endif
  else {
    xd->subpixel_predict        = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, bilinear4x4);
    xd->subpixel_predict8x4     = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, bilinear8x4);
    xd->subpixel_predict8x8     = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, bilinear8x8);
    xd->subpixel_predict16x16   = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, bilinear16x16);
    xd->subpixel_predict_avg    = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, bilinear_avg4x4);
    xd->subpixel_predict_avg8x8 = SUBPIX_INVOKE(
                                    &cpi->common.rtcd.subpix, bilinear_avg8x8);
    xd->subpixel_predict_avg16x16 = SUBPIX_INVOKE(
                                      &cpi->common.rtcd.subpix, bilinear_avg16x16);
  }

  // Reset frame count of inter 0,0 motion vector usage.
  cpi->inter_zz_count = 0;

  cpi->prediction_error = 0;
  cpi->intra_error = 0;
  cpi->skip_true_count[0] = cpi->skip_true_count[1] = cpi->skip_true_count[2] = 0;
  cpi->skip_false_count[0] = cpi->skip_false_count[1] = cpi->skip_false_count[2] = 0;

#if CONFIG_PRED_FILTER
  if (cm->current_video_frame == 0) {
    // Initially assume that we'll signal the prediction filter
    // state at the frame level and that it is off.
    cpi->common.pred_filter_mode = 0;
    cpi->common.prob_pred_filter_off = 128;
  }
  cpi->pred_filter_on_count = 0;
  cpi->pred_filter_off_count = 0;

#endif

#if 0
  // Experimental code
  cpi->frame_distortion = 0;
  cpi->last_mb_distortion = 0;
#endif

  xd->mode_info_context = cm->mi;
  xd->prev_mode_info_context = cm->prev_mi;

  vp8_zero(cpi->MVcount);
#if CONFIG_HIGH_PRECISION_MV
  vp8_zero(cpi->MVcount_hp);
#endif
  vp8_zero(cpi->coef_counts);
  vp8_zero(cpi->coef_counts_8x8);

  vp8cx_frame_init_quantizer(cpi);

  vp8_initialize_rd_consts(cpi, cm->base_qindex + cm->y1dc_delta_q);
  vp8cx_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-initencode frame context.
  init_encode_frame_mb_context(cpi);

  cpi->rd_single_diff = cpi->rd_comp_diff = cpi->rd_hybrid_diff = 0;
  vpx_memset(cpi->single_pred_count, 0, sizeof(cpi->single_pred_count));
  vpx_memset(cpi->comp_pred_count, 0, sizeof(cpi->comp_pred_count));

  {
    struct vpx_usec_timer  emr_timer;
    vpx_usec_timer_start(&emr_timer);

    {
      // For each row of SBs in the frame
      for (mb_row = 0; mb_row < cm->mb_rows; mb_row += 2) {
        int offset = (cm->mb_cols + 1) & ~0x1;

        encode_sb_row(cpi, cm, mb_row, x, xd, &tp, &totalrate);

        // adjust to the next row of SBs
        x->src.y_buffer += 32 * x->src.y_stride - 16 * offset;
        x->src.u_buffer += 16 * x->src.uv_stride - 8 * offset;
        x->src.v_buffer += 16 * x->src.uv_stride - 8 * offset;
      }

      cpi->tok_count = tp - cpi->tok;
    }

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

  }

  // 256 rate units to the bit,
  // projected_frame_size in units of BYTES
  cpi->projected_frame_size = totalrate >> 8;


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

}

static int check_dual_ref_flags(VP8_COMP *cpi) {
  MACROBLOCKD *xd = &cpi->mb.e_mbd;
  int ref_flags = cpi->ref_frame_flags;

  if (segfeature_active(xd, 1, SEG_LVL_REF_FRAME)) {
    if ((ref_flags & (VP8_LAST_FLAG | VP8_GOLD_FLAG)) == (VP8_LAST_FLAG | VP8_GOLD_FLAG) &&
        check_segref(xd, 1, LAST_FRAME))
      return 1;
    if ((ref_flags & (VP8_GOLD_FLAG | VP8_ALT_FLAG)) == (VP8_GOLD_FLAG | VP8_ALT_FLAG) &&
        check_segref(xd, 1, GOLDEN_FRAME))
      return 1;
    if ((ref_flags & (VP8_ALT_FLAG  | VP8_LAST_FLAG)) == (VP8_ALT_FLAG  | VP8_LAST_FLAG) &&
        check_segref(xd, 1, ALTREF_FRAME))
      return 1;
    return 0;
  } else {
    return (!!(ref_flags & VP8_GOLD_FLAG) +
            !!(ref_flags & VP8_LAST_FLAG) +
            !!(ref_flags & VP8_ALT_FLAG)) >= 2;
  }
}

void vp8_encode_frame(VP8_COMP *cpi) {
  if (cpi->sf.RD) {
    int frame_type, pred_type;
    int single_diff, comp_diff, hybrid_diff;

    /*
     * 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. If the difference is above a certain
     * threshold, it will actually re-encode the current frame using
     * that different coding mode.
     */
    if (cpi->common.frame_type == KEY_FRAME)
      frame_type = 0;
    else if (cpi->is_src_frame_alt_ref && cpi->common.refresh_golden_frame)
      frame_type = 3;
    else if (cpi->common.refresh_golden_frame || cpi->common.refresh_alt_ref_frame)
      frame_type = 1;
    else
      frame_type = 2;

    if (frame_type == 3)
      pred_type = SINGLE_PREDICTION_ONLY;
    else if (cpi->rd_prediction_type_threshes[frame_type][1] >
                 cpi->rd_prediction_type_threshes[frame_type][0] &&
             cpi->rd_prediction_type_threshes[frame_type][1] >
                 cpi->rd_prediction_type_threshes[frame_type][2] &&
             check_dual_ref_flags(cpi) && cpi->static_mb_pct == 100)
      pred_type = COMP_PREDICTION_ONLY;
    else if (cpi->rd_prediction_type_threshes[frame_type][0] >
                 cpi->rd_prediction_type_threshes[frame_type][2])
      pred_type = SINGLE_PREDICTION_ONLY;
    else
      pred_type = HYBRID_PREDICTION;

    cpi->common.comp_pred_mode = pred_type;
    encode_frame_internal(cpi);

    single_diff = cpi->rd_single_diff / cpi->common.MBs;
    cpi->rd_prediction_type_threshes[frame_type][0] += single_diff;
    cpi->rd_prediction_type_threshes[frame_type][0] >>= 1;
    comp_diff   = cpi->rd_comp_diff   / cpi->common.MBs;
    cpi->rd_prediction_type_threshes[frame_type][1] += comp_diff;
    cpi->rd_prediction_type_threshes[frame_type][1] >>= 1;
    hybrid_diff = cpi->rd_hybrid_diff / cpi->common.MBs;
    cpi->rd_prediction_type_threshes[frame_type][2] += hybrid_diff;
    cpi->rd_prediction_type_threshes[frame_type][2] >>= 1;

    if (cpi->common.comp_pred_mode == HYBRID_PREDICTION) {
      int single_count_zero = 0;
      int comp_count_zero = 0;
      int i;

      for (i = 0; i < COMP_PRED_CONTEXTS; i++) {
        single_count_zero += cpi->single_pred_count[i];
        comp_count_zero += cpi->comp_pred_count[i];
      }

      if (comp_count_zero == 0) {
        cpi->common.comp_pred_mode = SINGLE_PREDICTION_ONLY;
      } else if (single_count_zero == 0) {
        cpi->common.comp_pred_mode = COMP_PREDICTION_ONLY;
      }
    }
  } else {
    encode_frame_internal(cpi);
  }

}

void vp8_setup_block_ptrs(MACROBLOCK *x) {
  int r, c;
  int i;

  for (r = 0; r < 4; r++) {
    for (c = 0; c < 4; c++) {
      x->block[r * 4 + c].src_diff = x->src_diff + r * 4 * 16 + c * 4;
    }
  }

  for (r = 0; r < 2; r++) {
    for (c = 0; c < 2; c++) {
      x->block[16 + r * 2 + c].src_diff = x->src_diff + 256 + r * 4 * 8 + c * 4;
    }
  }


  for (r = 0; r < 2; r++) {
    for (c = 0; c < 2; c++) {
      x->block[20 + r * 2 + c].src_diff = x->src_diff + 320 + r * 4 * 8 + c * 4;
    }
  }

  x->block[24].src_diff = x->src_diff + 384;


  for (i = 0; i < 25; i++) {
    x->block[i].coeff = x->coeff + i * 16;
  }
}

void vp8_build_block_offsets(MACROBLOCK *x) {
  int block = 0;
  int br, bc;

  vp8_build_block_doffsets(&x->e_mbd);

  // y blocks
  x->thismb_ptr = &x->thismb[0];
  for (br = 0; br < 4; br++) {
    for (bc = 0; bc < 4; bc++) {
      BLOCK *this_block = &x->block[block];
      // this_block->base_src = &x->src.y_buffer;
      // this_block->src_stride = x->src.y_stride;
      // this_block->src = 4 * br * this_block->src_stride + 4 * bc;
      this_block->base_src = &x->thismb_ptr;
      this_block->src_stride = 16;
      this_block->src = 4 * br * 16 + 4 * bc;
      ++block;
    }
  }

  // u blocks
  for (br = 0; br < 2; br++) {
    for (bc = 0; bc < 2; bc++) {
      BLOCK *this_block = &x->block[block];
      this_block->base_src = &x->src.u_buffer;
      this_block->src_stride = x->src.uv_stride;
      this_block->src = 4 * br * this_block->src_stride + 4 * bc;
      ++block;
    }
  }

  // v blocks
  for (br = 0; br < 2; br++) {
    for (bc = 0; bc < 2; bc++) {
      BLOCK *this_block = &x->block[block];
      this_block->base_src = &x->src.v_buffer;
      this_block->src_stride = x->src.uv_stride;
      this_block->src = 4 * br * this_block->src_stride + 4 * bc;
      ++block;
    }
  }
}

static void sum_intra_stats(VP8_COMP *cpi, MACROBLOCK *x) {
  const MACROBLOCKD *xd = & x->e_mbd;
  const MB_PREDICTION_MODE m = xd->mode_info_context->mbmi.mode;
  const MB_PREDICTION_MODE uvm = xd->mode_info_context->mbmi.uv_mode;

#ifdef MODE_STATS
  const int is_key = cpi->common.frame_type == KEY_FRAME;

  ++ (is_key ? uv_modes : inter_uv_modes)[uvm];
  ++ uv_modes_y[m][uvm];

  if (m == B_PRED) {
    unsigned int *const bct = is_key ? b_modes : inter_b_modes;

    int b = 0;

    do {
      ++ bct[xd->block[b].bmi.as_mode.first];
    } while (++b < 16);
  }

  if (m == I8X8_PRED) {
    i8x8_modes[xd->block[0].bmi.as_mode.first]++;
    i8x8_modes[xd->block[2].bmi.as_mode.first]++;
    i8x8_modes[xd->block[8].bmi.as_mode.first]++;
    i8x8_modes[xd->block[10].bmi.as_mode.first]++;
  }
#endif

  ++cpi->ymode_count[m];
  if (m != I8X8_PRED)
    ++cpi->y_uv_mode_count[m][uvm];
  else {
    cpi->i8x8_mode_count[xd->block[0].bmi.as_mode.first]++;
    cpi->i8x8_mode_count[xd->block[2].bmi.as_mode.first]++;
    cpi->i8x8_mode_count[xd->block[8].bmi.as_mode.first]++;
    cpi->i8x8_mode_count[xd->block[10].bmi.as_mode.first]++;
  }
  if (m == B_PRED) {
    int b = 0;
    do {
      ++ cpi->bmode_count[xd->block[b].bmi.as_mode.first];
    } while (++b < 16);
  }
}

// Experimental stub function to create a per MB zbin adjustment based on
// some previously calculated measure of MB activity.
static void adjust_act_zbin(VP8_COMP *cpi, MACROBLOCK *x) {
#if USE_ACT_INDEX
  x->act_zbin_adj = *(x->mb_activity_ptr);
#else
  int64_t a;
  int64_t b;
  int64_t act = *(x->mb_activity_ptr);

  // Apply the masking to the RD multiplier.
  a = act + 4 * cpi->activity_avg;
  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
}

void vp8cx_encode_intra_macro_block(VP8_COMP *cpi,
                                    MACROBLOCK *x,
                                    TOKENEXTRA **t,
                                    int output_enabled) {
  if ((cpi->oxcf.tuning == VP8_TUNE_SSIM) && output_enabled) {
    adjust_act_zbin(cpi, x);
    vp8_update_zbin_extra(cpi, x);
  }

  /* test code: set transform size based on mode selection */
  if (cpi->common.txfm_mode == ALLOW_8X8
      && x->e_mbd.mode_info_context->mbmi.mode != I8X8_PRED
      && x->e_mbd.mode_info_context->mbmi.mode != B_PRED) {
    x->e_mbd.mode_info_context->mbmi.txfm_size = TX_8X8;
    cpi->t8x8_count++;
  } else {
    x->e_mbd.mode_info_context->mbmi.txfm_size = TX_4X4;
    cpi->t4x4_count++;
  }

  if (x->e_mbd.mode_info_context->mbmi.mode == I8X8_PRED) {
    vp8_encode_intra8x8mby(IF_RTCD(&cpi->rtcd), x);
    vp8_encode_intra8x8mbuv(IF_RTCD(&cpi->rtcd), x);
  } else if (x->e_mbd.mode_info_context->mbmi.mode == B_PRED)
    vp8_encode_intra4x4mby(IF_RTCD(&cpi->rtcd), x);
  else
    vp8_encode_intra16x16mby(IF_RTCD(&cpi->rtcd), x);

  if (x->e_mbd.mode_info_context->mbmi.mode != I8X8_PRED)
    vp8_encode_intra16x16mbuv(IF_RTCD(&cpi->rtcd), x);

  if (output_enabled) {
    // Tokenize
    sum_intra_stats(cpi, x);
    vp8_tokenize_mb(cpi, &x->e_mbd, t);
  }
}
#ifdef SPEEDSTATS
extern int cnt_pm;
#endif

extern void vp8_fix_contexts(MACROBLOCKD *x);

void vp8cx_encode_inter_macroblock
(
  VP8_COMP *cpi, MACROBLOCK *x, TOKENEXTRA **t,
  int recon_yoffset, int recon_uvoffset,
  int output_enabled
) {
  VP8_COMMON *cm = &cpi->common;
  MACROBLOCKD *const xd = &x->e_mbd;
  unsigned char *segment_id = &xd->mode_info_context->mbmi.segment_id;
  int seg_ref_active;
  unsigned char ref_pred_flag;

  x->skip = 0;

  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 = 0;
    if (cpi->zbin_mode_boost_enabled) {
      if (xd->mode_info_context->mbmi.ref_frame != INTRA_FRAME) {
        if (xd->mode_info_context->mbmi.mode == ZEROMV) {
          if (xd->mode_info_context->mbmi.ref_frame != LAST_FRAME)
            cpi->zbin_mode_boost = GF_ZEROMV_ZBIN_BOOST;
          else
            cpi->zbin_mode_boost = LF_ZEROMV_ZBIN_BOOST;
        } else if (xd->mode_info_context->mbmi.mode == SPLITMV)
          cpi->zbin_mode_boost = 0;
        else
          cpi->zbin_mode_boost = MV_ZBIN_BOOST;
      }
    }

    vp8_update_zbin_extra(cpi, x);
  }

  seg_ref_active = segfeature_active(xd, *segment_id, SEG_LVL_REF_FRAME);

  // SET VARIOUS PREDICTION FLAGS

  // Did the chosen reference frame match its predicted value.
  ref_pred_flag = ((xd->mode_info_context->mbmi.ref_frame ==
                    get_pred_ref(cm, xd)));
  set_pred_flag(xd, PRED_REF, ref_pred_flag);

  /* test code: set transform size based on mode selection */
  if (cpi->common.txfm_mode == ALLOW_8X8
      && x->e_mbd.mode_info_context->mbmi.mode != I8X8_PRED
      && x->e_mbd.mode_info_context->mbmi.mode != B_PRED
      && x->e_mbd.mode_info_context->mbmi.mode != SPLITMV) {
    x->e_mbd.mode_info_context->mbmi.txfm_size = TX_8X8;
    cpi->t8x8_count++;
  } else {
    x->e_mbd.mode_info_context->mbmi.txfm_size = TX_4X4;
    cpi->t4x4_count++;
  }

  if (xd->mode_info_context->mbmi.ref_frame == INTRA_FRAME) {
    if (xd->mode_info_context->mbmi.mode == B_PRED) {
      vp8_encode_intra16x16mbuv(IF_RTCD(&cpi->rtcd), x);
      vp8_encode_intra4x4mby(IF_RTCD(&cpi->rtcd), x);
    } else if (xd->mode_info_context->mbmi.mode == I8X8_PRED) {
      vp8_encode_intra8x8mby(IF_RTCD(&cpi->rtcd), x);
      vp8_encode_intra8x8mbuv(IF_RTCD(&cpi->rtcd), x);
    } else {
      vp8_encode_intra16x16mbuv(IF_RTCD(&cpi->rtcd), x);
      vp8_encode_intra16x16mby(IF_RTCD(&cpi->rtcd), x);
    }

    if (output_enabled)
      sum_intra_stats(cpi, x);
  } else {
    int ref_fb_idx;

    if (xd->mode_info_context->mbmi.ref_frame == LAST_FRAME)
      ref_fb_idx = cpi->common.lst_fb_idx;
    else if (xd->mode_info_context->mbmi.ref_frame == GOLDEN_FRAME)
      ref_fb_idx = cpi->common.gld_fb_idx;
    else
      ref_fb_idx = cpi->common.alt_fb_idx;

    xd->pre.y_buffer = cpi->common.yv12_fb[ref_fb_idx].y_buffer + recon_yoffset;
    xd->pre.u_buffer = cpi->common.yv12_fb[ref_fb_idx].u_buffer + recon_uvoffset;
    xd->pre.v_buffer = cpi->common.yv12_fb[ref_fb_idx].v_buffer + recon_uvoffset;

    if (xd->mode_info_context->mbmi.second_ref_frame) {
      int second_ref_fb_idx;

      if (xd->mode_info_context->mbmi.second_ref_frame == LAST_FRAME)
        second_ref_fb_idx = cpi->common.lst_fb_idx;
      else if (xd->mode_info_context->mbmi.second_ref_frame == GOLDEN_FRAME)
        second_ref_fb_idx = cpi->common.gld_fb_idx;
      else
        second_ref_fb_idx = cpi->common.alt_fb_idx;

      xd->second_pre.y_buffer = cpi->common.yv12_fb[second_ref_fb_idx].y_buffer +
                                recon_yoffset;
      xd->second_pre.u_buffer = cpi->common.yv12_fb[second_ref_fb_idx].u_buffer +
                                recon_uvoffset;
      xd->second_pre.v_buffer = cpi->common.yv12_fb[second_ref_fb_idx].v_buffer +
                                recon_uvoffset;
    }

    if (!x->skip) {
      vp8_encode_inter16x16(IF_RTCD(&cpi->rtcd), x);

      // Clear mb_skip_coeff if mb_no_coeff_skip is not set
      if (!cpi->common.mb_no_coeff_skip)
        xd->mode_info_context->mbmi.mb_skip_coeff = 0;

    } else {
      vp8_build_inter16x16_predictors_mb(xd, xd->dst.y_buffer,
                                         xd->dst.u_buffer, xd->dst.v_buffer,
                                         xd->dst.y_stride, xd->dst.uv_stride);
    }
  }

  if (!x->skip) {
#ifdef ENC_DEBUG
    if (enc_debug) {
      int i;
      printf("Segment=%d [%d, %d]: %d %d:\n", x->e_mbd.mode_info_context->mbmi.segment_id, mb_col_debug, mb_row_debug, xd->mb_to_left_edge, xd->mb_to_top_edge);
      for (i = 0; i < 400; i++) {
        printf("%3d ", xd->qcoeff[i]);
        if (i % 16 == 15) printf("\n");
      }
      printf("\n");
      printf("eobs = ");
      for (i = 0; i < 25; i++)
        printf("%d:%d ", i, xd->block[i].eob);
      printf("\n");
      fflush(stdout);
    }
#endif
    if (output_enabled)
      vp8_tokenize_mb(cpi, xd, t);
#ifdef ENC_DEBUG
    if (enc_debug) {
      printf("Tokenized\n");
      fflush(stdout);
    }
#endif
  } else {
    int mb_skip_context =
      cpi->common.mb_no_coeff_skip ?
      (x->e_mbd.mode_info_context - 1)->mbmi.mb_skip_coeff +
      (x->e_mbd.mode_info_context - cpi->common.mode_info_stride)->mbmi.mb_skip_coeff :
      0;
    if (cpi->common.mb_no_coeff_skip) {
      xd->mode_info_context->mbmi.mb_skip_coeff = 1;
      cpi->skip_true_count[mb_skip_context]++;
      vp8_fix_contexts(xd);
    } else {
      vp8_stuff_mb(cpi, xd, t);
      xd->mode_info_context->mbmi.mb_skip_coeff = 0;
      cpi->skip_false_count[mb_skip_context]++;
    }
  }
}