text: /*
    Copyright (c) 2010 The WebM project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree. An additional intellectual property rights grant can be found
   *  in the file PATENTS.  All contributing project authors may
   *  be found in the AUTHORS file in the root of the source tree.
   */
  
  
  #include "vp9/decoder/vp9_treereader.h"
  #include "vp9/common/vp9_entropymv.h"
  #include "vp9/common/vp9_entropymode.h"
  #include "vp9/common/vp9_reconinter.h"
  #include "vp9/decoder/vp9_onyxd_int.h"
  #include "vp9/common/vp9_findnearmv.h"
  #include "vp9/common/vp9_common.h"
  #include "vp9/common/vp9_seg_common.h"
  #include "vp9/common/vp9_pred_common.h"
  #include "vp9/common/vp9_entropy.h"
  #include "vp9/decoder/vp9_decodemv.h"
  #include "vp9/common/vp9_mvref_common.h"
  #if CONFIG_DEBUG
  #include <assert.h>
  #endif
  
  // #define DEBUG_DEC_MV
  #ifdef DEBUG_DEC_MV
  int dec_mvcount = 0;
  #endif
  
  // #define DEC_DEBUG
  #ifdef DEC_DEBUG
  extern int dec_debug;
  #endif
  
  static B_PREDICTION_MODE read_bmode(vp9_reader *bc, const vp9_prob *p) {
    B_PREDICTION_MODE m = treed_read(bc, vp9_bmode_tree, p);
  #if CONFIG_NEWBINTRAMODES
    if (m == B_CONTEXT_PRED - CONTEXT_PRED_REPLACEMENTS)
      m = B_CONTEXT_PRED;
    assert(m < B_CONTEXT_PRED - CONTEXT_PRED_REPLACEMENTS || m == B_CONTEXT_PRED);
  #endif
    return m;
  }
  
  static B_PREDICTION_MODE read_kf_bmode(vp9_reader *bc, const vp9_prob *p) {
    return (B_PREDICTION_MODE)treed_read(bc, vp9_kf_bmode_tree, p);
  }
  
  static MB_PREDICTION_MODE read_ymode(vp9_reader *bc, const vp9_prob *p) {
    return (MB_PREDICTION_MODE)treed_read(bc, vp9_ymode_tree, p);
  }
  
  static MB_PREDICTION_MODE read_sb_ymode(vp9_reader *bc, const vp9_prob *p) {
    return (MB_PREDICTION_MODE)treed_read(bc, vp9_sb_ymode_tree, p);
  }
  
  static MB_PREDICTION_MODE read_kf_sb_ymode(vp9_reader *bc, const vp9_prob *p) {
    return (MB_PREDICTION_MODE)treed_read(bc, vp9_uv_mode_tree, p);
  }
  
  static MB_PREDICTION_MODE read_kf_mb_ymode(vp9_reader *bc, const vp9_prob *p) {
    return (MB_PREDICTION_MODE)treed_read(bc, vp9_kf_ymode_tree, p);
  }
  
  static int read_i8x8_mode(vp9_reader *bc, const vp9_prob *p) {
    return treed_read(bc, vp9_i8x8_mode_tree, p);
  }
  
  static MB_PREDICTION_MODE read_uv_mode(vp9_reader *bc, const vp9_prob *p) {
    return (MB_PREDICTION_MODE)treed_read(bc, vp9_uv_mode_tree, p);
  }
  
  // This function reads the current macro block's segnent id from the bitstream
  // It should only be called if a segment map update is indicated.
  static void read_mb_segid(vp9_reader *r, MB_MODE_INFO *mi, MACROBLOCKD *xd) {
    if (xd->segmentation_enabled && xd->update_mb_segmentation_map) {
      const vp9_prob *const p = xd->mb_segment_tree_probs;
      mi->segment_id = vp9_read(r, p[0]) ? 2 + vp9_read(r, p[2])
                                         : vp9_read(r, p[1]);
    }
  }
  
  // This function reads the current macro block's segnent id from the bitstream
  // It should only be called if a segment map update is indicated.
  static void read_mb_segid_except(VP9_COMMON *cm,
                                   vp9_reader *r, MB_MODE_INFO *mi,
                                   MACROBLOCKD *xd, int mb_row, int mb_col) {
    const int mb_index = mb_row * cm->mb_cols + mb_col;
    const int pred_seg_id = vp9_get_pred_mb_segid(cm, xd, mb_index);
    const vp9_prob *const p = xd->mb_segment_tree_probs;
    const vp9_prob prob = xd->mb_segment_mispred_tree_probs[pred_seg_id];
  
    if (xd->segmentation_enabled && xd->update_mb_segmentation_map) {
      mi->segment_id = vp9_read(r, prob)
          ? 2 + (pred_seg_id  < 2 ? vp9_read(r, p[2]) : (pred_seg_id == 2))
          :     (pred_seg_id >= 2 ? vp9_read(r, p[1]) : (pred_seg_id == 0));
    }
  }
  
  #if CONFIG_NEW_MVREF
  int vp9_read_mv_ref_id(vp9_reader *r, vp9_prob *ref_id_probs) {
    int ref_index = 0;
  
    if (vp9_read(r, ref_id_probs[0])) {
      ref_index++;
      if (vp9_read(r, ref_id_probs[1])) {
        ref_index++;
        if (vp9_read(r, ref_id_probs[2]))
          ref_index++;
      }
    }
    return ref_index;
  }
  #endif
  
  extern const int vp9_i8x8_block[4];
  static void kfread_modes(VP9D_COMP *pbi,
                           MODE_INFO *m,
                           int mb_row,
                           int mb_col,
                           BOOL_DECODER* const bc) {
    VP9_COMMON *const cm = &pbi->common;
    MACROBLOCKD *const xd  = &pbi->mb;
    const int mis = pbi->common.mode_info_stride;
    int map_index = mb_row * pbi->common.mb_cols + mb_col;
    MB_PREDICTION_MODE y_mode;
  
    m->mbmi.ref_frame = INTRA_FRAME;
  
    // Read the Macroblock segmentation map if it is being updated explicitly
    // this frame (reset to 0 by default).
    m->mbmi.segment_id = 0;
    if (pbi->mb.update_mb_segmentation_map) {
      read_mb_segid(bc, &m->mbmi, &pbi->mb);
      if (m->mbmi.sb_type) {
        const int nmbs = 1 << m->mbmi.sb_type;
        const int ymbs = MIN(cm->mb_rows - mb_row, nmbs);
        const int xmbs = MIN(cm->mb_cols - mb_col, nmbs);
        int x, y;
  
        for (y = 0; y < ymbs; y++) {
          for (x = 0; x < xmbs; x++) {
            cm->last_frame_seg_map[map_index + x + y * cm->mb_cols] =
                m->mbmi.segment_id;
          }
        }
      } else {
        cm->last_frame_seg_map[map_index] = m->mbmi.segment_id;
      }
    }
  
    m->mbmi.mb_skip_coeff = 0;
    if (pbi->common.mb_no_coeff_skip &&
        (!vp9_segfeature_active(&pbi->mb, m->mbmi.segment_id, SEG_LVL_SKIP))) {
      m->mbmi.mb_skip_coeff = vp9_read(bc, vp9_get_pred_prob(cm, &pbi->mb,
                                                             PRED_MBSKIP));
    } else {
      m->mbmi.mb_skip_coeff = vp9_segfeature_active(&pbi->mb, m->mbmi.segment_id,
                                                    SEG_LVL_SKIP);
    }
  
    y_mode = m->mbmi.sb_type ?
        read_kf_sb_ymode(bc,
            pbi->common.sb_kf_ymode_prob[pbi->common.kf_ymode_probs_index]):
        read_kf_mb_ymode(bc,
            pbi->common.kf_ymode_prob[pbi->common.kf_ymode_probs_index]);
  
    m->mbmi.ref_frame = INTRA_FRAME;
  
    if ((m->mbmi.mode = y_mode) == B_PRED) {
      int i = 0;
      do {
        const B_PREDICTION_MODE a = above_block_mode(m, i, mis);
        const B_PREDICTION_MODE l = (xd->left_available || (i & 3)) ?
                                    left_block_mode(m, i) : B_DC_PRED;
  
        m->bmi[i].as_mode.first = read_kf_bmode(bc,
                                                pbi->common.kf_bmode_prob[a][l]);
      } while (++i < 16);
    }
  
    if ((m->mbmi.mode = y_mode) == I8X8_PRED) {
      int i;
      for (i = 0; i < 4; i++) {
        const int ib = vp9_i8x8_block[i];
        const int mode8x8 = read_i8x8_mode(bc, pbi->common.fc.i8x8_mode_prob);
  
        m->bmi[ib + 0].as_mode.first = mode8x8;
        m->bmi[ib + 1].as_mode.first = mode8x8;
        m->bmi[ib + 4].as_mode.first = mode8x8;
        m->bmi[ib + 5].as_mode.first = mode8x8;
      }
    } else {
      m->mbmi.uv_mode = read_uv_mode(bc,
                                     pbi->common.kf_uv_mode_prob[m->mbmi.mode]);
    }
  
    if (cm->txfm_mode == TX_MODE_SELECT &&
        m->mbmi.mb_skip_coeff == 0 &&
        m->mbmi.mode <= I8X8_PRED) {
      // FIXME(rbultje) code ternary symbol once all experiments are merged
      m->mbmi.txfm_size = vp9_read(bc, cm->prob_tx[0]);
      if (m->mbmi.txfm_size != TX_4X4 && m->mbmi.mode != I8X8_PRED) {
        m->mbmi.txfm_size += vp9_read(bc, cm->prob_tx[1]);
        if (m->mbmi.txfm_size != TX_8X8 && m->mbmi.sb_type)
          m->mbmi.txfm_size += vp9_read(bc, cm->prob_tx[2]);
      }
    } else if (cm->txfm_mode >= ALLOW_32X32 && m->mbmi.sb_type) {
      m->mbmi.txfm_size = TX_32X32;
    } else if (cm->txfm_mode >= ALLOW_16X16 && m->mbmi.mode <= TM_PRED) {
      m->mbmi.txfm_size = TX_16X16;
    } else if (cm->txfm_mode >= ALLOW_8X8 && m->mbmi.mode != B_PRED) {
      m->mbmi.txfm_size = TX_8X8;
    } else {
      m->mbmi.txfm_size = TX_4X4;
    }
  }
  
  static int read_nmv_component(vp9_reader *r,
                                int rv,
                                const nmv_component *mvcomp) {
    int mag, d;
    const int sign = vp9_read(r, mvcomp->sign);
    const int mv_class = treed_read(r, vp9_mv_class_tree, mvcomp->classes);
  
    if (mv_class == MV_CLASS_0) {
      d = treed_read(r, vp9_mv_class0_tree, mvcomp->class0);
    } else {
      int i;
      int n = mv_class + CLASS0_BITS - 1;  // number of bits
  
      d = 0;
      for (i = 0; i < n; ++i)
        d |= vp9_read(r, mvcomp->bits[i]) << i;
    }
  
    mag = vp9_get_mv_mag(mv_class, d << 3);
    return sign ? -(mag + 8) : (mag + 8);
  }
  
  static int read_nmv_component_fp(vp9_reader *r,
                                   int v,
                                   int rv,
                                   const nmv_component *mvcomp,
                                   int usehp) {
    const int sign = v < 0;
    int mag = ((sign ? -v : v) - 1) & ~7;  // magnitude - 1
    int offset;
    const int mv_class = vp9_get_mv_class(mag, &offset);
    const int f = mv_class == MV_CLASS_0 ?
        treed_read(r, vp9_mv_fp_tree, mvcomp->class0_fp[offset >> 3]):
        treed_read(r, vp9_mv_fp_tree, mvcomp->fp);
  
    offset += f << 1;
  
    if (usehp) {
      const vp9_prob p = mv_class == MV_CLASS_0 ? mvcomp->class0_hp : mvcomp->hp;
      offset += vp9_read(r, p);
    } else {
      offset += 1;  // If hp is not used, the default value of the hp bit is 1
    }
    mag = vp9_get_mv_mag(mv_class, offset);
    return sign ? -(mag + 1) : (mag + 1);
  }
  
  static void read_nmv(vp9_reader *r, MV *mv, const MV *ref,
                       const nmv_context *mvctx) {
    const MV_JOINT_TYPE j = treed_read(r, vp9_mv_joint_tree, mvctx->joints);
    mv->row = mv-> col = 0;
    if (j == MV_JOINT_HZVNZ || j == MV_JOINT_HNZVNZ) {
      mv->row = read_nmv_component(r, ref->row, &mvctx->comps[0]);
    }
  
    if (j == MV_JOINT_HNZVZ || j == MV_JOINT_HNZVNZ) {
      mv->col = read_nmv_component(r, ref->col, &mvctx->comps[1]);
    }
  }
  
  static void read_nmv_fp(vp9_reader *r, MV *mv, const MV *ref,
                          const nmv_context *mvctx, int usehp) {
    const MV_JOINT_TYPE j = vp9_get_mv_joint(*mv);
    usehp = usehp && vp9_use_nmv_hp(ref);
    if (j == MV_JOINT_HZVNZ || j == MV_JOINT_HNZVNZ) {
      mv->row = read_nmv_component_fp(r, mv->row, ref->row, &mvctx->comps[0],
                                      usehp);
    }
    if (j == MV_JOINT_HNZVZ || j == MV_JOINT_HNZVNZ) {
      mv->col = read_nmv_component_fp(r, mv->col, ref->col, &mvctx->comps[1],
                                      usehp);
    }
    /*
    printf("MV: %d %d REF: %d %d\n", mv->row + ref->row, mv->col + ref->col,
  	 ref->row, ref->col);
  	 */
  }
  
  static void update_nmv(vp9_reader *bc, vp9_prob *const p,
                         const vp9_prob upd_p) {
    if (vp9_read(bc, upd_p)) {
  #ifdef LOW_PRECISION_MV_UPDATE
      *p = (vp9_read_literal(bc, 7) << 1) | 1;
  #else
      *p = (vp9_read_literal(bc, 8));
  #endif
    }
  }
  
  static void read_nmvprobs(vp9_reader *bc, nmv_context *mvctx,
                            int usehp) {
    int i, j, k;
  
  #ifdef MV_GROUP_UPDATE
    if (!vp9_read_bit(bc))
      return;
  #endif
    for (j = 0; j < MV_JOINTS - 1; ++j)
      update_nmv(bc, &mvctx->joints[j], VP9_NMV_UPDATE_PROB);
  
    for (i = 0; i < 2; ++i) {
      update_nmv(bc, &mvctx->comps[i].sign, VP9_NMV_UPDATE_PROB);
      for (j = 0; j < MV_CLASSES - 1; ++j)
        update_nmv(bc, &mvctx->comps[i].classes[j], VP9_NMV_UPDATE_PROB);
  
      for (j = 0; j < CLASS0_SIZE - 1; ++j)
        update_nmv(bc, &mvctx->comps[i].class0[j], VP9_NMV_UPDATE_PROB);
  
      for (j = 0; j < MV_OFFSET_BITS; ++j)
        update_nmv(bc, &mvctx->comps[i].bits[j], VP9_NMV_UPDATE_PROB);
    }
  
    for (i = 0; i < 2; ++i) {
      for (j = 0; j < CLASS0_SIZE; ++j) {
        for (k = 0; k < 3; ++k)
          update_nmv(bc, &mvctx->comps[i].class0_fp[j][k], VP9_NMV_UPDATE_PROB);
      }
  
      for (j = 0; j < 3; ++j)
        update_nmv(bc, &mvctx->comps[i].fp[j], VP9_NMV_UPDATE_PROB);
    }
  
    if (usehp) {
      for (i = 0; i < 2; ++i) {
        update_nmv(bc, &mvctx->comps[i].class0_hp, VP9_NMV_UPDATE_PROB);
        update_nmv(bc, &mvctx->comps[i].hp, VP9_NMV_UPDATE_PROB);
      }
    }
  }
  
  // Read the referncence frame
  static MV_REFERENCE_FRAME read_ref_frame(VP9D_COMP *pbi,
                                           vp9_reader *const bc,
                                           unsigned char segment_id) {
    MV_REFERENCE_FRAME ref_frame;
    VP9_COMMON *const cm = &pbi->common;
    MACROBLOCKD *const xd = &pbi->mb;
  
    int seg_ref_count = 0;
    int seg_ref_active = vp9_segfeature_active(xd, segment_id, SEG_LVL_REF_FRAME);
  
    // If segment coding enabled does the segment allow for more than one
    // possible reference frame
    if (seg_ref_active) {
      seg_ref_count = vp9_check_segref(xd, segment_id, INTRA_FRAME) +
                      vp9_check_segref(xd, segment_id, LAST_FRAME) +
                      vp9_check_segref(xd, segment_id, GOLDEN_FRAME) +
                      vp9_check_segref(xd, segment_id, ALTREF_FRAME);
    }
  
    // Segment reference frame features not available or allows for
    // multiple reference frame options
    if (!seg_ref_active || (seg_ref_count > 1)) {
      // Values used in prediction model coding
      MV_REFERENCE_FRAME pred_ref;
  
      // Get the context probability the prediction flag
      vp9_prob pred_prob = vp9_get_pred_prob(cm, xd, PRED_REF);
  
      // Read the prediction status flag
      unsigned char prediction_flag = vp9_read(bc, pred_prob);
  
      // Store the prediction flag.
      vp9_set_pred_flag(xd, PRED_REF, prediction_flag);
  
      // Get the predicted reference frame.
      pred_ref = vp9_get_pred_ref(cm, xd);
  
      // If correctly predicted then use the predicted value
      if (prediction_flag) {
        ref_frame = pred_ref;
      } else {
        // decode the explicitly coded value
        vp9_prob mod_refprobs[PREDICTION_PROBS];
        vpx_memcpy(mod_refprobs,
                   cm->mod_refprobs[pred_ref], sizeof(mod_refprobs));
  
        // If segment coding enabled blank out options that cant occur by
        // setting the branch probability to 0.
        if (seg_ref_active) {
          mod_refprobs[INTRA_FRAME] *=
            vp9_check_segref(xd, segment_id, INTRA_FRAME);
          mod_refprobs[LAST_FRAME] *=
            vp9_check_segref(xd, segment_id, LAST_FRAME);
          mod_refprobs[GOLDEN_FRAME] *=
            (vp9_check_segref(xd, segment_id, GOLDEN_FRAME) *
             vp9_check_segref(xd, segment_id, ALTREF_FRAME));
        }
  
        // Default to INTRA_FRAME (value 0)
        ref_frame = INTRA_FRAME;
  
        // Do we need to decode the Intra/Inter branch
        if (mod_refprobs[0])
          ref_frame = (MV_REFERENCE_FRAME) vp9_read(bc, mod_refprobs[0]);
        else
          ref_frame++;
  
        if (ref_frame) {
          // Do we need to decode the Last/Gf_Arf branch
          if (mod_refprobs[1])
            ref_frame += vp9_read(bc, mod_refprobs[1]);
          else
            ref_frame++;
  
          if (ref_frame > 1) {
            // Do we need to decode the GF/Arf branch
            if (mod_refprobs[2])
              ref_frame += vp9_read(bc, mod_refprobs[2]);
            else {
              if (seg_ref_active) {
                if ((pred_ref == GOLDEN_FRAME) ||
                    !vp9_check_segref(xd, segment_id, GOLDEN_FRAME)) {
                  ref_frame = ALTREF_FRAME;
                } else
                  ref_frame = GOLDEN_FRAME;
              } else
                ref_frame = (pred_ref == GOLDEN_FRAME)
                            ? ALTREF_FRAME : GOLDEN_FRAME;
            }
          }
        }
      }
    } else {
      // Segment reference frame features are enabled
      // The reference frame for the mb is considered as correclty predicted
      // if it is signaled at the segment level for the purposes of the
      // common prediction model
      vp9_set_pred_flag(xd, PRED_REF, 1);
      ref_frame = vp9_get_pred_ref(cm, xd);
    }
  
    return (MV_REFERENCE_FRAME)ref_frame;
  }
  
  static MB_PREDICTION_MODE read_sb_mv_ref(vp9_reader *bc, const vp9_prob *p) {
    return (MB_PREDICTION_MODE) treed_read(bc, vp9_sb_mv_ref_tree, p);
  }
  
  static MB_PREDICTION_MODE read_mv_ref(vp9_reader *bc, const vp9_prob *p) {
    return (MB_PREDICTION_MODE) treed_read(bc, vp9_mv_ref_tree, p);
  }
  
  static B_PREDICTION_MODE sub_mv_ref(vp9_reader *bc, const vp9_prob *p) {
    return (B_PREDICTION_MODE) treed_read(bc, vp9_sub_mv_ref_tree, p);
  }
  
  #ifdef VPX_MODE_COUNT
  unsigned int vp9_mv_cont_count[5][4] = {
    { 0, 0, 0, 0 },
    { 0, 0, 0, 0 },
    { 0, 0, 0, 0 },
    { 0, 0, 0, 0 },
    { 0, 0, 0, 0 }
  };
  #endif
  
  static const unsigned char mbsplit_fill_count[4] = { 8, 8, 4, 1 };
  static const unsigned char mbsplit_fill_offset[4][16] = {
    { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15 },
    { 0,  1,  4,  5,  8,  9, 12, 13,  2,  3,   6,  7, 10, 11, 14, 15 },
    { 0,  1,  4,  5,  2,  3,  6,  7,  8,  9,  12, 13, 10, 11, 14, 15 },
    { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15 }
  };
  
  static void read_switchable_interp_probs(VP9D_COMP* const pbi,
                                           BOOL_DECODER* const bc) {
    VP9_COMMON *const cm = &pbi->common;
    int i, j;
    for (j = 0; j <= VP9_SWITCHABLE_FILTERS; ++j) {
      for (i = 0; i < VP9_SWITCHABLE_FILTERS - 1; ++i) {
        cm->fc.switchable_interp_prob[j][i] = vp9_read_prob(bc);
      }
    }
    //printf("DECODER: %d %d\n", cm->fc.switchable_interp_prob[0],
    //cm->fc.switchable_interp_prob[1]);
  }
  
  static void mb_mode_mv_init(VP9D_COMP *pbi, vp9_reader *bc) {
    VP9_COMMON *const cm = &pbi->common;
    nmv_context *const nmvc = &pbi->common.fc.nmvc;
    MACROBLOCKD *const xd  = &pbi->mb;
  
    if (cm->frame_type == KEY_FRAME) {
      if (!cm->kf_ymode_probs_update)
        cm->kf_ymode_probs_index = vp9_read_literal(bc, 3);
    } else {
      if (cm->mcomp_filter_type == SWITCHABLE)
        read_switchable_interp_probs(pbi, bc);
  #if CONFIG_COMP_INTERINTRA_PRED
      if (cm->use_interintra) {
        if (vp9_read(bc, VP9_UPD_INTERINTRA_PROB))
          cm->fc.interintra_prob = vp9_read_prob(bc);
      }
  #endif
      // Decode the baseline probabilities for decoding reference frame
      cm->prob_intra_coded = vp9_read_prob(bc);
      cm->prob_last_coded  = vp9_read_prob(bc);
      cm->prob_gf_coded    = vp9_read_prob(bc);
  
      // Computes a modified set of probabilities for use when reference
      // frame prediction fails.
      vp9_compute_mod_refprobs(cm);
  
      pbi->common.comp_pred_mode = vp9_read(bc, 128);
      if (cm->comp_pred_mode)
        cm->comp_pred_mode += vp9_read(bc, 128);
      if (cm->comp_pred_mode == HYBRID_PREDICTION) {
        int i;
        for (i = 0; i < COMP_PRED_CONTEXTS; i++)
          cm->prob_comppred[i] = vp9_read_prob(bc);
      }
  
      if (vp9_read_bit(bc)) {
        int i = 0;
  
        do {
          cm->fc.ymode_prob[i] = vp9_read_prob(bc);
        } while (++i < VP9_YMODES - 1);
      }
  
      if (vp9_read_bit(bc)) {
        int i = 0;
  
        do {
          cm->fc.sb_ymode_prob[i] = vp9_read_prob(bc);
        } while (++i < VP9_I32X32_MODES - 1);
      }
  
      read_nmvprobs(bc, nmvc, xd->allow_high_precision_mv);
    }
  }
  
  // This function either reads the segment id for the current macroblock from
  // the bitstream or if the value is temporally predicted asserts the predicted
  // value
  static void read_mb_segment_id(VP9D_COMP *pbi,
                                 int mb_row, int mb_col,
                                 BOOL_DECODER* const bc) {
    VP9_COMMON *const cm = &pbi->common;
    MACROBLOCKD *const xd = &pbi->mb;
    MODE_INFO *mi = xd->mode_info_context;
    MB_MODE_INFO *mbmi = &mi->mbmi;
    int mb_index = mb_row * pbi->common.mb_cols + mb_col;
  
    if (xd->segmentation_enabled) {
      if (xd->update_mb_segmentation_map) {
        // Is temporal coding of the segment id for this mb enabled.
        if (cm->temporal_update) {
          // Get the context based probability for reading the
          // prediction status flag
          vp9_prob pred_prob = vp9_get_pred_prob(cm, xd, PRED_SEG_ID);
  
          // Read the prediction status flag
          unsigned char seg_pred_flag = vp9_read(bc, pred_prob);
  
          // Store the prediction flag.
          vp9_set_pred_flag(xd, PRED_SEG_ID, seg_pred_flag);
  
          // If the value is flagged as correctly predicted
          // then use the predicted value
          if (seg_pred_flag) {
            mbmi->segment_id = vp9_get_pred_mb_segid(cm, xd, mb_index);
          } else {
            // Decode it explicitly
            read_mb_segid_except(cm, bc, mbmi, xd, mb_row, mb_col);
          }
        } else {
          // Normal unpredicted coding mode
          read_mb_segid(bc, mbmi, xd);
        }
  
        if (mbmi->sb_type) {
          const int nmbs = 1 << mbmi->sb_type;
          const int ymbs = MIN(cm->mb_rows - mb_row, nmbs);
          const int xmbs = MIN(cm->mb_cols - mb_col, nmbs);
          int x, y;
  
          for (y = 0; y < ymbs; y++) {
            for (x = 0; x < xmbs; x++) {
              cm->last_frame_seg_map[mb_index + x + y * cm->mb_cols] =
                  mbmi->segment_id;
            }
          }
        } else {
          cm->last_frame_seg_map[mb_index] = mbmi->segment_id;
        }
      } else {
        if (mbmi->sb_type) {
          const int nmbs = 1 << mbmi->sb_type;
          const int ymbs = MIN(cm->mb_rows - mb_row, nmbs);
          const int xmbs = MIN(cm->mb_cols - mb_col, nmbs);
          unsigned segment_id = -1;
          int x, y;
  
          for (y = 0; y < ymbs; y++) {
            for (x = 0; x < xmbs; x++) {
              segment_id = MIN(segment_id,
                  cm->last_frame_seg_map[mb_index + x + y * cm->mb_cols]);
            }
          }
          mbmi->segment_id = segment_id;
        } else {
          mbmi->segment_id = cm->last_frame_seg_map[mb_index];
        }
      }
    } else {
      // The encoder explicitly sets the segment_id to 0
      // when segmentation is disabled
      mbmi->segment_id = 0;
    }
  }
  
  
  static INLINE void assign_and_clamp_mv(int_mv *dst, const int_mv *src,
                                         int mb_to_left_edge,
                                         int mb_to_right_edge,
                                         int mb_to_top_edge,
                                         int mb_to_bottom_edge) {
    dst->as_int = src->as_int;
    clamp_mv(dst, mb_to_left_edge, mb_to_right_edge, mb_to_top_edge,
             mb_to_bottom_edge);
  }
  
  static INLINE void process_mv(BOOL_DECODER* bc, MV *mv, MV *ref,
                                nmv_context *nmvc, nmv_context_counts *mvctx,
                                int usehp) {
    read_nmv(bc, mv, ref, nmvc);
    read_nmv_fp(bc, mv, ref, nmvc, usehp);
    vp9_increment_nmv(mv, ref, mvctx, usehp);
    mv->row += ref->row;
    mv->col += ref->col;
  }
  
  static void read_mb_modes_mv(VP9D_COMP *pbi, MODE_INFO *mi, MB_MODE_INFO *mbmi,
                               MODE_INFO *prev_mi,
                               int mb_row, int mb_col,
                               BOOL_DECODER* const bc) {
    VP9_COMMON *const cm = &pbi->common;
    nmv_context *const nmvc = &pbi->common.fc.nmvc;
    const int mis = pbi->common.mode_info_stride;
    MACROBLOCKD *const xd = &pbi->mb;
  
    int_mv *const mv = &mbmi->mv[0];
    const int mb_size = 1 << mi->mbmi.sb_type;
  
    const int use_prev_in_find_mv_refs = cm->width == cm->last_width &&
                                         cm->height == cm->last_height &&
                                         !cm->error_resilient_mode;
  
    int mb_to_left_edge, mb_to_right_edge, mb_to_top_edge, mb_to_bottom_edge;
  
    mbmi->need_to_clamp_mvs = 0;
    mbmi->need_to_clamp_secondmv = 0;
    mbmi->second_ref_frame = NONE;
  
    // Make sure the MACROBLOCKD mode info pointer is pointed at the
    // correct entry for the current macroblock.
    xd->mode_info_context = mi;
    xd->prev_mode_info_context = prev_mi;
  
    // Distance of Mb to the various image edges.
    // These specified to 8th pel as they are always compared to MV values
    // that are in 1/8th pel units
    set_mb_row(cm, xd, mb_row, mb_size);
    set_mb_col(cm, xd, mb_col, mb_size);
  
    mb_to_top_edge = xd->mb_to_top_edge - LEFT_TOP_MARGIN;
    mb_to_bottom_edge = xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN;
    mb_to_left_edge = xd->mb_to_left_edge - LEFT_TOP_MARGIN;
    mb_to_right_edge = xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN;
  
    // Read the macroblock segment id.
    read_mb_segment_id(pbi, mb_row, mb_col, bc);
  
    if (pbi->common.mb_no_coeff_skip &&
        (!vp9_segfeature_active(xd, mbmi->segment_id, SEG_LVL_SKIP))) {
      // Read the macroblock coeff skip flag if this feature is in use,
      // else default to 0
      mbmi->mb_skip_coeff = vp9_read(bc, vp9_get_pred_prob(cm, xd, PRED_MBSKIP));
    } else {
      mbmi->mb_skip_coeff = vp9_segfeature_active(xd, mbmi->segment_id,
                                                  SEG_LVL_SKIP);
    }
  
    // Read the reference frame
    mbmi->ref_frame = read_ref_frame(pbi, bc, mbmi->segment_id);
  
    /*
    if (pbi->common.current_video_frame == 1)
      printf("ref frame: %d [%d %d]\n", mbmi->ref_frame, mb_row, mb_col);
      */
  
    // If reference frame is an Inter frame
    if (mbmi->ref_frame) {
      int_mv nearest, nearby, best_mv;
      int_mv nearest_second, nearby_second, best_mv_second;
      vp9_prob mv_ref_p[VP9_MVREFS - 1];
  
      MV_REFERENCE_FRAME ref_frame = mbmi->ref_frame;
      xd->scale_factor[0] = cm->active_ref_scale[mbmi->ref_frame - 1];
  
      {
        const int use_prev_in_find_best_ref =
            xd->scale_factor[0].x_num == xd->scale_factor[0].x_den &&
            xd->scale_factor[0].y_num == xd->scale_factor[0].y_den &&
            !cm->error_resilient_mode &&
            !cm->frame_parallel_decoding_mode;
  
        /* Select the appropriate reference frame for this MB */
        const int ref_fb_idx = cm->active_ref_idx[ref_frame - 1];
  
        setup_pred_block(&xd->pre, &cm->yv12_fb[ref_fb_idx],
            mb_row, mb_col, &xd->scale_factor[0], &xd->scale_factor_uv[0]);
  
  #ifdef DEC_DEBUG
        if (dec_debug)
          printf("%d %d\n", xd->mode_info_context->mbmi.mv[0].as_mv.row,
                 xd->mode_info_context->mbmi.mv[0].as_mv.col);
  #endif
        // if (cm->current_video_frame == 1 && mb_row == 4 && mb_col == 5)
        //  printf("Dello\n");
        vp9_find_mv_refs(cm, xd, mi, use_prev_in_find_mv_refs ? prev_mi : NULL,
                         ref_frame, mbmi->ref_mvs[ref_frame],
                         cm->ref_frame_sign_bias);
  
        vp9_mv_ref_probs(&pbi->common, mv_ref_p,
                         mbmi->mb_mode_context[ref_frame]);
  
        // If the segment level skip mode enabled
        if (vp9_segfeature_active(xd, mbmi->segment_id, SEG_LVL_SKIP)) {
          mbmi->mode = ZEROMV;
        } else {
          mbmi->mode = mbmi->sb_type ? read_sb_mv_ref(bc, mv_ref_p)
                                     : read_mv_ref(bc, mv_ref_p);
          vp9_accum_mv_refs(&pbi->common, mbmi->mode,
                            mbmi->mb_mode_context[ref_frame]);
        }
  
        if (mbmi->mode != ZEROMV) {
          vp9_find_best_ref_mvs(xd,
                                use_prev_in_find_best_ref ?
                                    xd->pre.y_buffer : NULL,
                                xd->pre.y_stride,
                                mbmi->ref_mvs[ref_frame],
                                &nearest, &nearby);
  
          best_mv.as_int = (mbmi->ref_mvs[ref_frame][0]).as_int;
        }
  
  #ifdef DEC_DEBUG
        if (dec_debug)
          printf("[D %d %d] %d %d %d %d\n", ref_frame,
                 mbmi->mb_mode_context[ref_frame],
                 mv_ref_p[0], mv_ref_p[1], mv_ref_p[2], mv_ref_p[3]);
  #endif
      }
  
      if (mbmi->mode >= NEARESTMV && mbmi->mode <= SPLITMV) {
        if (cm->mcomp_filter_type == SWITCHABLE) {
          mbmi->interp_filter = vp9_switchable_interp[
              treed_read(bc, vp9_switchable_interp_tree,
                         vp9_get_pred_probs(cm, xd, PRED_SWITCHABLE_INTERP))];
        } else {
          mbmi->interp_filter = cm->mcomp_filter_type;
        }
      }
  
      if (cm->comp_pred_mode == COMP_PREDICTION_ONLY ||
          (cm->comp_pred_mode == HYBRID_PREDICTION &&
           vp9_read(bc, vp9_get_pred_prob(cm, xd, PRED_COMP)))) {
        /* Since we have 3 reference frames, we can only have 3 unique
         * combinations of combinations of 2 different reference frames
         * (A-G, G-L or A-L). In the bitstream, we use this to simply
         * derive the second reference frame from the first reference
         * frame, by saying it's the next one in the enumerator, and
         * if that's > n_refs, then the second reference frame is the
         * first one in the enumerator. */
        mbmi->second_ref_frame = mbmi->ref_frame + 1;
        if (mbmi->second_ref_frame == 4)
          mbmi->second_ref_frame = 1;
        if (mbmi->second_ref_frame > 0) {
          int second_ref_fb_idx;
          int use_prev_in_find_best_ref;
  
          xd->scale_factor[1] = cm->active_ref_scale[mbmi->second_ref_frame - 1];
          use_prev_in_find_best_ref =
              xd->scale_factor[1].x_num == xd->scale_factor[1].x_den &&
              xd->scale_factor[1].y_num == xd->scale_factor[1].y_den &&
              !cm->error_resilient_mode &&
              !cm->frame_parallel_decoding_mode;
  
          /* Select the appropriate reference frame for this MB */
          second_ref_fb_idx = cm->active_ref_idx[mbmi->second_ref_frame - 1];
  
          setup_pred_block(&xd->second_pre, &cm->yv12_fb[second_ref_fb_idx],
               mb_row, mb_col, &xd->scale_factor[1], &xd->scale_factor_uv[1]);
  
          vp9_find_mv_refs(cm, xd, mi, use_prev_in_find_mv_refs ? prev_mi : NULL,
                           mbmi->second_ref_frame,
                           mbmi->ref_mvs[mbmi->second_ref_frame],
                           cm->ref_frame_sign_bias);
  
          if (mbmi->mode != ZEROMV) {
            vp9_find_best_ref_mvs(xd,
                                  use_prev_in_find_best_ref ?
                                      xd->second_pre.y_buffer : NULL,
                                  xd->second_pre.y_stride,
                                  mbmi->ref_mvs[mbmi->second_ref_frame],
                                  &nearest_second,
                                  &nearby_second);
            best_mv_second = mbmi->ref_mvs[mbmi->second_ref_frame][0];
          }
        }
  
      } else {
  #if CONFIG_COMP_INTERINTRA_PRED
        if (pbi->common.use_interintra &&
            mbmi->mode >= NEARESTMV && mbmi->mode < SPLITMV &&
            mbmi->second_ref_frame == NONE) {
          mbmi->second_ref_frame = (vp9_read(bc, pbi->common.fc.interintra_prob) ?
                                    INTRA_FRAME : NONE);
          // printf("-- %d (%d)\n", mbmi->second_ref_frame == INTRA_FRAME,
          //        pbi->common.fc.interintra_prob);
          pbi->common.fc.interintra_counts[
              mbmi->second_ref_frame == INTRA_FRAME]++;
          if (mbmi->second_ref_frame == INTRA_FRAME) {
            mbmi->interintra_mode = read_ymode(bc, pbi->common.fc.ymode_prob);
            pbi->common.fc.ymode_counts[mbmi->interintra_mode]++;
  #if SEPARATE_INTERINTRA_UV
            mbmi->interintra_uv_mode = read_uv_mode(bc,
                pbi->common.fc.uv_mode_prob[mbmi->interintra_mode]);
            pbi->common.fc.uv_mode_counts[mbmi->interintra_mode]
                                         [mbmi->interintra_uv_mode]++;
  #else
            mbmi->interintra_uv_mode = mbmi->interintra_mode;
  #endif
            // printf("** %d %d\n",
            //        mbmi->interintra_mode, mbmi->interintra_uv_mode);
          }
        }
  #endif
      }
  
  #if CONFIG_NEW_MVREF
      // if ((mbmi->mode == NEWMV) || (mbmi->mode == SPLITMV))
      if (mbmi->mode == NEWMV) {
        int best_index;
        MV_REFERENCE_FRAME ref_frame = mbmi->ref_frame;
  
        // Encode the index of the choice.
        best_index =
          vp9_read_mv_ref_id(bc, xd->mb_mv_ref_probs[ref_frame]);
  
        best_mv.as_int = mbmi->ref_mvs[ref_frame][best_index].as_int;
  
        if (mbmi->second_ref_frame > 0) {
          ref_frame = mbmi->second_ref_frame;
  
          // Encode the index of the choice.
          best_index =
            vp9_read_mv_ref_id(bc, xd->mb_mv_ref_probs[ref_frame]);
          best_mv_second.as_int = mbmi->ref_mvs[ref_frame][best_index].as_int;
        }
      }
  #endif
  
      mbmi->uv_mode = DC_PRED;
      switch (mbmi->mode) {
        case SPLITMV: {
          const int s = treed_read(bc, vp9_mbsplit_tree, cm->fc.mbsplit_prob);
          const int num_p = vp9_mbsplit_count[s];
          int j = 0;
  
          cm->fc.mbsplit_counts[s]++;
          mbmi->need_to_clamp_mvs = 0;
          mbmi->partitioning = s;
          do {  // for each subset j
            int_mv leftmv, abovemv, second_leftmv, second_abovemv;
            int_mv blockmv, secondmv;
            int mv_contz;
            int blockmode;
            int k = vp9_mbsplit_offset[s][j];  // first block in subset j
  
            leftmv.as_int = left_block_mv(xd, mi, k);
            abovemv.as_int = above_block_mv(mi, k, mis);
            second_leftmv.as_int = 0;
            second_abovemv.as_int = 0;
            if (mbmi->second_ref_frame > 0) {
              second_leftmv.as_int = left_block_second_mv(xd, mi, k);
              second_abovemv.as_int = above_block_second_mv(mi, k, mis);
            }
            mv_contz = vp9_mv_cont(&leftmv, &abovemv);
            blockmode = sub_mv_ref(bc, cm->fc.sub_mv_ref_prob [mv_contz]);
            cm->fc.sub_mv_ref_counts[mv_contz][blockmode - LEFT4X4]++;
  
            switch (blockmode) {
              case NEW4X4:
                process_mv(bc, &blockmv.as_mv, &best_mv.as_mv, nmvc,
                           &cm->fc.NMVcount, xd->allow_high_precision_mv);
  
                if (mbmi->second_ref_frame > 0)
                  process_mv(bc, &secondmv.as_mv, &best_mv_second.as_mv, nmvc,
                             &cm->fc.NMVcount, xd->allow_high_precision_mv);
  
  #ifdef VPX_MODE_COUNT
                vp9_mv_cont_count[mv_contz][3]++;
  #endif
                break;
              case LEFT4X4:
                blockmv.as_int = leftmv.as_int;
                if (mbmi->second_ref_frame > 0)
                  secondmv.as_int = second_leftmv.as_int;
  #ifdef VPX_MODE_COUNT
                vp9_mv_cont_count[mv_contz][0]++;
  #endif
                break;
              case ABOVE4X4:
                blockmv.as_int = abovemv.as_int;
                if (mbmi->second_ref_frame > 0)
                  secondmv.as_int = second_abovemv.as_int;
  #ifdef VPX_MODE_COUNT
                vp9_mv_cont_count[mv_contz][1]++;
  #endif
                break;
              case ZERO4X4:
                blockmv.as_int = 0;
                if (mbmi->second_ref_frame > 0)
                  secondmv.as_int = 0;
  #ifdef VPX_MODE_COUNT
                vp9_mv_cont_count[mv_contz][2]++;
  #endif
                break;
              default:
                break;
            }
  
            /*  Commenting this section out, not sure why this was needed, and
             *  there are mismatches with this section in rare cases since it is
             *  not done in the encoder at all.
            mbmi->need_to_clamp_mvs |= check_mv_bounds(&blockmv,
                                                       mb_to_left_edge,
                                                       mb_to_right_edge,
                                                       mb_to_top_edge,
                                                       mb_to_bottom_edge);
            if (mbmi->second_ref_frame > 0) {
              mbmi->need_to_clamp_mvs |= check_mv_bounds(&secondmv,
                                                         mb_to_left_edge,
                                                         mb_to_right_edge,
                                                         mb_to_top_edge,
                                                         mb_to_bottom_edge);
            }
            */
  
            {
              /* Fill (uniform) modes, mvs of jth subset.
               Must do it here because ensuing subsets can
               refer back to us via "left" or "above". */
              unsigned int fill_count = mbsplit_fill_count[s];
              const unsigned char *fill_offset =
                  &mbsplit_fill_offset[s][j * fill_count];
  
              do {
                mi->bmi[*fill_offset].as_mv[0].as_int = blockmv.as_int;
                if (mbmi->second_ref_frame > 0)
                  mi->bmi[*fill_offset].as_mv[1].as_int = secondmv.as_int;
                fill_offset++;
              } while (--fill_count);
            }
  
          } while (++j < num_p);
        }
  
        mv->as_int = mi->bmi[15].as_mv[0].as_int;
        mbmi->mv[1].as_int = mi->bmi[15].as_mv[1].as_int;
  
        break;  /* done with SPLITMV */
  
        case NEARMV:
          // Clip "next_nearest" so that it does not extend to far out of image
          assign_and_clamp_mv(mv, &nearby, mb_to_left_edge,
                                           mb_to_right_edge,
                                           mb_to_top_edge,
                                           mb_to_bottom_edge);
          if (mbmi->second_ref_frame > 0)
            assign_and_clamp_mv(&mbmi->mv[1], &nearby_second, mb_to_left_edge,
                                                              mb_to_right_edge,
                                                              mb_to_top_edge,
                                                              mb_to_bottom_edge);
          break;
  
        case NEARESTMV:
          // Clip "next_nearest" so that it does not extend to far out of image
          assign_and_clamp_mv(mv, &nearest, mb_to_left_edge,
                                            mb_to_right_edge,
                                            mb_to_top_edge,
                                            mb_to_bottom_edge);
          if (mbmi->second_ref_frame > 0)
            assign_and_clamp_mv(&mbmi->mv[1], &nearest_second, mb_to_left_edge,
                                                               mb_to_right_edge,
                                                               mb_to_top_edge,
                                                               mb_to_bottom_edge);
          break;
  
        case ZEROMV:
          mv->as_int = 0;
          if (mbmi->second_ref_frame > 0)
            mbmi->mv[1].as_int = 0;
          break;
  
        case NEWMV:
          process_mv(bc, &mv->as_mv, &best_mv.as_mv, nmvc, &cm->fc.NMVcount,
                     xd->allow_high_precision_mv);
  
          // Don't need to check this on NEARMV and NEARESTMV modes
          // since those modes clamp the MV. The NEWMV mode does not,
          // so signal to the prediction stage whether special
          // handling may be required.
          mbmi->need_to_clamp_mvs = check_mv_bounds(mv,
                                                    mb_to_left_edge,
                                                    mb_to_right_edge,
                                                    mb_to_top_edge,
                                                    mb_to_bottom_edge);
  
          if (mbmi->second_ref_frame > 0) {
            process_mv(bc, &mbmi->mv[1].as_mv, &best_mv_second.as_mv, nmvc,
                       &cm->fc.NMVcount, xd->allow_high_precision_mv);
            mbmi->need_to_clamp_secondmv |= check_mv_bounds(&mbmi->mv[1],
                                                            mb_to_left_edge,
                                                            mb_to_right_edge,
                                                            mb_to_top_edge,
                                                            mb_to_bottom_edge);
          }
          break;
        default:
  ;
  #if CONFIG_DEBUG
          assert(0);
  #endif
      }
    } else {
      /* required for left and above block mv */
      mbmi->mv[0].as_int = 0;
  
      if (mbmi->sb_type) {
        mbmi->mode = read_sb_ymode(bc, pbi->common.fc.sb_ymode_prob);
        pbi->common.fc.sb_ymode_counts[mbmi->mode]++;
      } else {
        mbmi->mode = read_ymode(bc, pbi->common.fc.ymode_prob);
        pbi->common.fc.ymode_counts[mbmi->mode]++;
      }
  
      // If MB mode is BPRED read the block modes
      if (mbmi->mode == B_PRED) {
        int j = 0;
        do {
          int m = read_bmode(bc, pbi->common.fc.bmode_prob);
          mi->bmi[j].as_mode.first = m;
  #if CONFIG_NEWBINTRAMODES
          if (m == B_CONTEXT_PRED) m -= CONTEXT_PRED_REPLACEMENTS;
  #endif
          pbi->common.fc.bmode_counts[m]++;
        } while (++j < 16);
      }
  
      if (mbmi->mode == I8X8_PRED) {
        int i;
        for (i = 0; i < 4; i++) {
          const int ib = vp9_i8x8_block[i];
          const int mode8x8 = read_i8x8_mode(bc, pbi->common.fc.i8x8_mode_prob);
  
          mi->bmi[ib + 0].as_mode.first = mode8x8;
          mi->bmi[ib + 1].as_mode.first = mode8x8;
          mi->bmi[ib + 4].as_mode.first = mode8x8;
          mi->bmi[ib + 5].as_mode.first = mode8x8;
          pbi->common.fc.i8x8_mode_counts[mode8x8]++;
        }
      } else {
        mbmi->uv_mode = read_uv_mode(bc, pbi->common.fc.uv_mode_prob[mbmi->mode]);
        pbi->common.fc.uv_mode_counts[mbmi->mode][mbmi->uv_mode]++;
      }
    }
    /*
    if (pbi->common.current_video_frame == 1)
      printf("mode: %d skip: %d\n", mbmi->mode, mbmi->mb_skip_coeff);
      */
  
    if (cm->txfm_mode == TX_MODE_SELECT && mbmi->mb_skip_coeff == 0 &&
        ((mbmi->ref_frame == INTRA_FRAME && mbmi->mode <= I8X8_PRED) ||
         (mbmi->ref_frame != INTRA_FRAME && !(mbmi->mode == SPLITMV &&
                             mbmi->partitioning == PARTITIONING_4X4)))) {
      // FIXME(rbultje) code ternary symbol once all experiments are merged
      mbmi->txfm_size = vp9_read(bc, cm->prob_tx[0]);
      if (mbmi->txfm_size != TX_4X4 && mbmi->mode != I8X8_PRED &&
          mbmi->mode != SPLITMV) {
        mbmi->txfm_size += vp9_read(bc, cm->prob_tx[1]);
        if (mbmi->sb_type && mbmi->txfm_size != TX_8X8)
          mbmi->txfm_size += vp9_read(bc, cm->prob_tx[2]);
      }
    } else if (mbmi->sb_type && cm->txfm_mode >= ALLOW_32X32) {
      mbmi->txfm_size = TX_32X32;
    } else if (cm->txfm_mode >= ALLOW_16X16 &&
        ((mbmi->ref_frame == INTRA_FRAME && mbmi->mode <= TM_PRED) ||
         (mbmi->ref_frame != INTRA_FRAME && mbmi->mode != SPLITMV))) {
      mbmi->txfm_size = TX_16X16;
    } else if (cm->txfm_mode >= ALLOW_8X8 &&
        (!(mbmi->ref_frame == INTRA_FRAME && mbmi->mode == B_PRED) &&
         !(mbmi->ref_frame != INTRA_FRAME && mbmi->mode == SPLITMV &&
           mbmi->partitioning == PARTITIONING_4X4))) {
      mbmi->txfm_size = TX_8X8;
    } else {
      mbmi->txfm_size = TX_4X4;
    }
  }
  
  void vp9_decode_mode_mvs_init(VP9D_COMP* const pbi, BOOL_DECODER* const bc) {
    VP9_COMMON *cm = &pbi->common;
  
    vpx_memset(cm->mbskip_pred_probs, 0, sizeof(cm->mbskip_pred_probs));
    if (pbi->common.mb_no_coeff_skip) {
      int k;
      for (k = 0; k < MBSKIP_CONTEXTS; ++k) {
        cm->mbskip_pred_probs[k] = vp9_read_prob(bc);
      }
    }
  
    mb_mode_mv_init(pbi, bc);
  }
  
  #if CONFIG_CODE_NONZEROCOUNT
  static uint16_t read_nzc(VP9_COMMON *const cm,
                           int nzc_context,
                           TX_SIZE tx_size,
                           int ref,
                           int type,
                           BOOL_DECODER* const bc) {
    int c, e;
    uint16_t nzc;
    if (tx_size == TX_32X32) {
      c = treed_read(bc, vp9_nzc32x32_tree,
                     cm->fc.nzc_probs_32x32[nzc_context][ref][type]);
      cm->fc.nzc_counts_32x32[nzc_context][ref][type][c]++;
    } else if (tx_size == TX_16X16) {
      c = treed_read(bc, vp9_nzc16x16_tree,
                     cm->fc.nzc_probs_16x16[nzc_context][ref][type]);
      cm->fc.nzc_counts_16x16[nzc_context][ref][type][c]++;
    } else if (tx_size == TX_8X8) {
      c = treed_read(bc, vp9_nzc8x8_tree,
                     cm->fc.nzc_probs_8x8[nzc_context][ref][type]);
      cm->fc.nzc_counts_8x8[nzc_context][ref][type][c]++;
    } else if (tx_size == TX_4X4) {
      c = treed_read(bc, vp9_nzc4x4_tree,
                     cm->fc.nzc_probs_4x4[nzc_context][ref][type]);
      cm->fc.nzc_counts_4x4[nzc_context][ref][type][c]++;
    } else {
      assert(0);
    }
    nzc = vp9_basenzcvalue[c];
    if ((e = vp9_extranzcbits[c])) {
      int x = 0;
      while (e--) {
        int b = vp9_read(
            bc, cm->fc.nzc_pcat_probs[nzc_context][c - NZC_TOKENS_NOEXTRA][e]);
        x |= (b << e);
        cm->fc.nzc_pcat_counts[nzc_context][c - NZC_TOKENS_NOEXTRA][e][b]++;
      }
      nzc += x;
    }
    if (tx_size == TX_32X32)
      assert(nzc <= 1024);
    else if (tx_size == TX_16X16)
      assert(nzc <= 256);
    else if (tx_size == TX_8X8)
      assert(nzc <= 64);
    else if (tx_size == TX_4X4)
      assert(nzc <= 16);
    return nzc;
  }
  
  static void read_nzcs_sb64(VP9_COMMON *const cm,
                             MACROBLOCKD* xd,
                             int mb_row,
                             int mb_col,
                             BOOL_DECODER* const bc) {
    MODE_INFO *m = xd->mode_info_context;
    MB_MODE_INFO *const mi = &m->mbmi;
    int j, nzc_context;
    const int ref = m->mbmi.ref_frame != INTRA_FRAME;
  
    assert(mb_col == get_mb_col(xd));
    assert(mb_row == get_mb_row(xd));
  
    vpx_memset(m->mbmi.nzcs, 0, 384 * sizeof(m->mbmi.nzcs[0]));
  
    if (mi->mb_skip_coeff)
      return;
  
    switch (mi->txfm_size) {
      case TX_32X32:
        for (j = 0; j < 256; j += 64) {
          nzc_context = vp9_get_nzc_context_y_sb64(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_32X32, ref, 0, bc);
        }
        for (j = 256; j < 384; j += 64) {
          nzc_context = vp9_get_nzc_context_uv_sb64(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_32X32, ref, 1, bc);
        }
        break;
  
      case TX_16X16:
        for (j = 0; j < 256; j += 16) {
          nzc_context = vp9_get_nzc_context_y_sb64(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_16X16, ref, 0, bc);
        }
        for (j = 256; j < 384; j += 16) {
          nzc_context = vp9_get_nzc_context_uv_sb64(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_16X16, ref, 1, bc);
        }
        break;
  
      case TX_8X8:
        for (j = 0; j < 256; j += 4) {
          nzc_context = vp9_get_nzc_context_y_sb64(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_8X8, ref, 0, bc);
        }
        for (j = 256; j < 384; j += 4) {
          nzc_context = vp9_get_nzc_context_uv_sb64(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_8X8, ref, 1, bc);
        }
        break;
  
      case TX_4X4:
        for (j = 0; j < 256; ++j) {
          nzc_context = vp9_get_nzc_context_y_sb64(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_4X4, ref, 0, bc);
        }
        for (j = 256; j < 384; ++j) {
          nzc_context = vp9_get_nzc_context_uv_sb64(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_4X4, ref, 1, bc);
        }
        break;
  
      default:
        break;
    }
  }
  
  static void read_nzcs_sb32(VP9_COMMON *const cm,
                             MACROBLOCKD* xd,
                             int mb_row,
                             int mb_col,
                             BOOL_DECODER* const bc) {
    MODE_INFO *m = xd->mode_info_context;
    MB_MODE_INFO *const mi = &m->mbmi;
    int j, nzc_context;
    const int ref = m->mbmi.ref_frame != INTRA_FRAME;
  
    assert(mb_col == get_mb_col(xd));
    assert(mb_row == get_mb_row(xd));
  
    vpx_memset(m->mbmi.nzcs, 0, 384 * sizeof(m->mbmi.nzcs[0]));
  
    if (mi->mb_skip_coeff)
      return;
  
    switch (mi->txfm_size) {
      case TX_32X32:
        for (j = 0; j < 64; j += 64) {
          nzc_context = vp9_get_nzc_context_y_sb32(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_32X32, ref, 0, bc);
        }
        for (j = 64; j < 96; j += 16) {
          nzc_context = vp9_get_nzc_context_uv_sb32(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_16X16, ref, 1, bc);
        }
        break;
  
      case TX_16X16:
        for (j = 0; j < 64; j += 16) {
          nzc_context = vp9_get_nzc_context_y_sb32(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_16X16, ref, 0, bc);
        }
        for (j = 64; j < 96; j += 16) {
          nzc_context = vp9_get_nzc_context_uv_sb32(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_16X16, ref, 1, bc);
        }
        break;
  
      case TX_8X8:
        for (j = 0; j < 64; j += 4) {
          nzc_context = vp9_get_nzc_context_y_sb32(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_8X8, ref, 0, bc);
        }
        for (j = 64; j < 96; j += 4) {
          nzc_context = vp9_get_nzc_context_uv_sb32(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_8X8, ref, 1, bc);
        }
        break;
  
      case TX_4X4:
        for (j = 0; j < 64; ++j) {
          nzc_context = vp9_get_nzc_context_y_sb32(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_4X4, ref, 0, bc);
        }
        for (j = 64; j < 96; ++j) {
          nzc_context = vp9_get_nzc_context_uv_sb32(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_4X4, ref, 1, bc);
        }
        break;
  
      default:
        break;
    }
  }
  
  static void read_nzcs_mb16(VP9_COMMON *const cm,
                             MACROBLOCKD* xd,
                             int mb_row,
                             int mb_col,
                             BOOL_DECODER* const bc) {
    MODE_INFO *m = xd->mode_info_context;
    MB_MODE_INFO *const mi = &m->mbmi;
    int j, nzc_context;
    const int ref = m->mbmi.ref_frame != INTRA_FRAME;
  
    assert(mb_col == get_mb_col(xd));
    assert(mb_row == get_mb_row(xd));
  
    vpx_memset(m->mbmi.nzcs, 0, 384 * sizeof(m->mbmi.nzcs[0]));
  
    if (mi->mb_skip_coeff)
      return;
  
    switch (mi->txfm_size) {
      case TX_16X16:
        for (j = 0; j < 16; j += 16) {
          nzc_context = vp9_get_nzc_context_y_mb16(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_16X16, ref, 0, bc);
        }
        for (j = 16; j < 24; j += 4) {
          nzc_context = vp9_get_nzc_context_uv_mb16(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_8X8, ref, 1, bc);
        }
        break;
  
      case TX_8X8:
        for (j = 0; j < 16; j += 4) {
          nzc_context = vp9_get_nzc_context_y_mb16(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_8X8, ref, 0, bc);
        }
        if (mi->mode == I8X8_PRED || mi->mode == SPLITMV) {
          for (j = 16; j < 24; ++j) {
            nzc_context = vp9_get_nzc_context_uv_mb16(cm, m, mb_row, mb_col, j);
            m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_4X4, ref, 1, bc);
          }
        } else {
          for (j = 16; j < 24; j += 4) {
            nzc_context = vp9_get_nzc_context_uv_mb16(cm, m, mb_row, mb_col, j);
            m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_8X8, ref, 1, bc);
          }
        }
        break;
  
      case TX_4X4:
        for (j = 0; j < 16; ++j) {
          nzc_context = vp9_get_nzc_context_y_mb16(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_4X4, ref, 0, bc);
        }
        for (j = 16; j < 24; ++j) {
          nzc_context = vp9_get_nzc_context_uv_mb16(cm, m, mb_row, mb_col, j);
          m->mbmi.nzcs[j] = read_nzc(cm, nzc_context, TX_4X4, ref, 1, bc);
        }
        break;
  
      default:
        break;
    }
  }
  #endif  // CONFIG_CODE_NONZEROCOUNT
  
  void vp9_decode_mb_mode_mv(VP9D_COMP* const pbi,
                             MACROBLOCKD* const xd,
                             int mb_row,
                             int mb_col,
                             BOOL_DECODER* const bc) {
    VP9_COMMON *const cm = &pbi->common;
    MODE_INFO *mi = xd->mode_info_context;
    MODE_INFO *prev_mi = xd->prev_mode_info_context;
    MB_MODE_INFO *const mbmi = &mi->mbmi;
  
    if (pbi->common.frame_type == KEY_FRAME) {
      kfread_modes(pbi, mi, mb_row, mb_col, bc);
    } else {
      read_mb_modes_mv(pbi, mi, &mi->mbmi, prev_mi, mb_row, mb_col, bc);
      set_scale_factors(xd,
                        mi->mbmi.ref_frame - 1, mi->mbmi.second_ref_frame - 1,
                        pbi->common.active_ref_scale);
    }
  #if CONFIG_CODE_NONZEROCOUNT
    if (mbmi->sb_type == BLOCK_SIZE_SB64X64)
      read_nzcs_sb64(cm, xd, mb_row, mb_col, bc);
    else if (mbmi->sb_type == BLOCK_SIZE_SB32X32)
      read_nzcs_sb32(cm, xd, mb_row, mb_col, bc);
    else
      read_nzcs_mb16(cm, xd, mb_row, mb_col, bc);
  #endif  // CONFIG_CODE_NONZEROCOUNT
  
    if (mbmi->sb_type) {
      const int n_mbs = 1 << mbmi->sb_type;
      const int y_mbs = MIN(n_mbs, cm->mb_rows - mb_row);
      const int x_mbs = MIN(n_mbs, cm->mb_cols - mb_col);
      const int mis = cm->mode_info_stride;
      int x, y;
  
      for (y = 0; y < y_mbs; y++) {
        for (x = !y; x < x_mbs; x++) {
          mi[y * mis + x] = *mi;
        }
      }
    } else {
      update_blockd_bmi(xd);
    }
  }
  