libvpx: Add VP9 decoder.

source/libvpx/vp9/decoder/vp9_decodemv.c

+/*
+  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/decoder/vp9_onyxd_int.h"
+#include "vp9/common/vp9_findnearmv.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 int 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 int read_kf_bmode(vp9_reader *bc, const vp9_prob *p) {
+  return treed_read(bc, vp9_kf_bmode_tree, p);
+}
+
+static int read_ymode(vp9_reader *bc, const vp9_prob *p) {
+  return treed_read(bc, vp9_ymode_tree, p);
+}
+
+#if CONFIG_SUPERBLOCKS
+static int read_sb_ymode(vp9_reader *bc, const vp9_prob *p) {
+  return treed_read(bc, vp9_sb_ymode_tree, p);
+}
+
+static int read_kf_sb_ymode(vp9_reader *bc, const vp9_prob *p) {
+  return treed_read(bc, vp9_uv_mode_tree, p);
+}
+#endif
+
+static int read_kf_mb_ymode(vp9_reader *bc, const vp9_prob *p) {
+  return 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 int read_uv_mode(vp9_reader *bc, const vp9_prob *p) {
+  return 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) {
+  /* Is segmentation enabled */
+  if (xd->segmentation_enabled && xd->update_mb_segmentation_map) {
+    /* If so then read the segment id. */
+    if (vp9_read(r, xd->mb_segment_tree_probs[0]))
+      mi->segment_id =
+        (unsigned char)(2 + vp9_read(r, xd->mb_segment_tree_probs[2]));
+    else
+      mi->segment_id =
+        (unsigned char)(vp9_read(r, xd->mb_segment_tree_probs[1]));
+  }
+}
+
+#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;
+  const int mis = pbi->common.mode_info_stride;
+  int map_index = mb_row * pbi->common.mb_cols + mb_col;
+  MB_PREDICTION_MODE y_mode;
+
+  // 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);
+    pbi->common.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_EOB) ||
+       (vp9_get_segdata(&pbi->mb,
+                        m->mbmi.segment_id, SEG_LVL_EOB) != 0))) {
+    MACROBLOCKD *const xd  = &pbi->mb;
+    m->mbmi.mb_skip_coeff =
+      vp9_read(bc, vp9_get_pred_prob(cm, xd, PRED_MBSKIP));
+  } else {
+    if (vp9_segfeature_active(&pbi->mb,
+                              m->mbmi.segment_id, SEG_LVL_EOB) &&
+        (vp9_get_segdata(&pbi->mb,
+                         m->mbmi.segment_id, SEG_LVL_EOB) == 0)) {
+      m->mbmi.mb_skip_coeff = 1;
+    } else
+      m->mbmi.mb_skip_coeff = 0;
+  }
+
+#if CONFIG_SUPERBLOCKS
+  if (m->mbmi.encoded_as_sb) {
+    y_mode = (MB_PREDICTION_MODE) read_kf_sb_ymode(bc,
+      pbi->common.sb_kf_ymode_prob[pbi->common.kf_ymode_probs_index]);
+  } else
+#endif
+  y_mode = (MB_PREDICTION_MODE) read_kf_mb_ymode(bc,
+    pbi->common.kf_ymode_prob[pbi->common.kf_ymode_probs_index]);
+#if CONFIG_COMP_INTRA_PRED
+  m->mbmi.second_mode = (MB_PREDICTION_MODE)(DC_PRED - 1);
+#endif
+
+  m->mbmi.ref_frame = INTRA_FRAME;
+
+  if ((m->mbmi.mode = y_mode) == B_PRED) {
+    int i = 0;
+#if CONFIG_COMP_INTRA_PRED
+    int use_comp_pred = vp9_read(bc, DEFAULT_COMP_INTRA_PROB);
+#endif
+    do {
+      const B_PREDICTION_MODE A = above_block_mode(m, i, mis);
+      const B_PREDICTION_MODE L = left_block_mode(m, i);
+
+      m->bmi[i].as_mode.first =
+        (B_PREDICTION_MODE) read_kf_bmode(
+          bc, pbi->common.kf_bmode_prob [A] [L]);
+#if CONFIG_COMP_INTRA_PRED
+      if (use_comp_pred) {
+        m->bmi[i].as_mode.second =
+          (B_PREDICTION_MODE) read_kf_bmode(
+            bc, pbi->common.kf_bmode_prob [A] [L]);
+      } else {
+        m->bmi[i].as_mode.second = (B_PREDICTION_MODE)(B_DC_PRED - 1);
+      }
+#endif
+    } while (++i < 16);
+  }
+  if ((m->mbmi.mode = y_mode) == I8X8_PRED) {
+    int i;
+    int mode8x8;
+    for (i = 0; i < 4; i++) {
+      int ib = vp9_i8x8_block[i];
+      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;
+#if CONFIG_COMP_INTRA_PRED
+      m->bmi[ib + 0].as_mode.second = (MB_PREDICTION_MODE)(DC_PRED - 1);
+      m->bmi[ib + 1].as_mode.second = (MB_PREDICTION_MODE)(DC_PRED - 1);
+      m->bmi[ib + 4].as_mode.second = (MB_PREDICTION_MODE)(DC_PRED - 1);
+      m->bmi[ib + 5].as_mode.second = (MB_PREDICTION_MODE)(DC_PRED - 1);
+#endif
+    }
+  } else
+    m->mbmi.uv_mode = (MB_PREDICTION_MODE)read_uv_mode(bc,
+                                                       pbi->common.kf_uv_mode_prob[m->mbmi.mode]);
+#if CONFIG_COMP_INTRA_PRED
+  m->mbmi.second_uv_mode = (MB_PREDICTION_MODE)(DC_PRED - 1);
+#endif
+
+  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]);
+  } 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 v, s, z, c, o, d;
+  s = vp9_read(r, mvcomp->sign);
+  c = treed_read(r, vp9_mv_class_tree, mvcomp->classes);
+  if (c == MV_CLASS_0) {
+    d = treed_read(r, vp9_mv_class0_tree, mvcomp->class0);
+  } else {
+    int i, b;
+    d = 0;
+    b = c + CLASS0_BITS - 1;  /* number of bits */
+    for (i = 0; i < b; ++i)
+      d |= (vp9_read(r, mvcomp->bits[i]) << i);
+  }
+  o = d << 3;
+
+  z = vp9_get_mv_mag(c, o);
+  v = (s ? -(z + 8) : (z + 8));
+  return v;
+}
+
+static int read_nmv_component_fp(vp9_reader *r,
+                                 int v,
+                                 int rv,
+                                 const nmv_component *mvcomp,
+                                 int usehp) {
+  int s, z, c, o, d, e, f;
+  s = v < 0;
+  z = (s ? -v : v) - 1;       /* magnitude - 1 */
+  z &= ~7;
+
+  c = vp9_get_mv_class(z, &o);
+  d = o >> 3;
+
+  if (c == MV_CLASS_0) {
+    f = treed_read(r, vp9_mv_fp_tree, mvcomp->class0_fp[d]);
+  } else {
+    f = treed_read(r, vp9_mv_fp_tree, mvcomp->fp);
+  }
+  o += (f << 1);
+
+  if (usehp) {
+    if (c == MV_CLASS_0) {
+      e = vp9_read(r, mvcomp->class0_hp);
+    } else {
+      e = vp9_read(r, mvcomp->hp);
+    }
+    o += e;
+  } else {
+    ++o;  /* Note if hp is not used, the default value of the hp bit is 1 */
+  }
+  z = vp9_get_mv_mag(c, o);
+  v = (s ? -(z + 1) : (z + 1));
+  return v;
+}
+
+static void read_nmv(vp9_reader *r, MV *mv, const MV *ref,
+                     const nmv_context *mvctx) {
+  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) {
+  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("  %d: %d %d ref: %d %d\n", usehp, mv->row, mv-> 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;
+  int seg_ref_active;
+  int seg_ref_count = 0;
+
+  VP9_COMMON *const cm = &pbi->common;
+  MACROBLOCKD *const xd = &pbi->mb;
+
+  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
+    unsigned char prediction_flag;
+    vp9_prob pred_prob;
+    MV_REFERENCE_FRAME pred_ref;
+
+    // Get the context probability the prediction flag
+    pred_prob = vp9_get_pred_prob(cm, xd, PRED_REF);
+
+    // Read the prediction status flag
+    prediction_flag = (unsigned char)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
+    else {
+      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;
+          }
+        }
+      }
+    }
+  }
+
+  // Segment reference frame features are enabled
+  else {
+    // 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;
+}
+
+#if CONFIG_SUPERBLOCKS
+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);
+}
+#endif
+
+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_literal(bc, 8);
+    }
+  }
+  //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 CONFIG_PRED_FILTER
+    cm->pred_filter_mode = (vp9_prob)vp9_read_literal(bc, 2);
+
+    if (cm->pred_filter_mode == 2)
+      cm->prob_pred_filter_off = (vp9_prob)vp9_read_literal(bc, 8);
+#endif
+    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_prob)vp9_read_literal(bc, 8);
+    }
+#endif
+    // Decode the baseline probabilities for decoding reference frame
+    cm->prob_intra_coded = (vp9_prob)vp9_read_literal(bc, 8);
+    cm->prob_last_coded  = (vp9_prob)vp9_read_literal(bc, 8);
+    cm->prob_gf_coded    = (vp9_prob)vp9_read_literal(bc, 8);
+
+    // 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_prob)vp9_read_literal(bc, 8);
+    }
+
+    if (vp9_read_bit(bc)) {
+      int i = 0;
+
+      do {
+        cm->fc.ymode_prob[i] = (vp9_prob) vp9_read_literal(bc, 8);
+      } while (++i < VP9_YMODES - 1);
+    }
+
+#if CONFIG_SUPERBLOCKS
+    if (vp9_read_bit(bc)) {
+      int i = 0;
+
+      do {
+        cm->fc.sb_ymode_prob[i] = (vp9_prob) vp9_read_literal(bc, 8);
+      } while (++i < VP9_I32X32_MODES - 1);
+    }
+#endif
+
+#if CONFIG_NEW_MVREF
+  // Temp defaults probabilities for ecnoding the MV ref id signal
+  vpx_memset(xd->mb_mv_ref_id_probs, 192, sizeof(xd->mb_mv_ref_id_probs));
+#endif
+
+    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 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 =
+          (unsigned char)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, index);
+        }
+        // Else .... decode it explicitly
+        else {
+          read_mb_segid(bc, mbmi, xd);
+        }
+      }
+      // Normal unpredicted coding mode
+      else {
+        read_mb_segid(bc, mbmi, xd);
+      }
+#if CONFIG_SUPERBLOCKS
+      if (mbmi->encoded_as_sb) {
+        cm->last_frame_seg_map[index] = mbmi->segment_id;
+        if (mb_col + 1 < cm->mb_cols)
+          cm->last_frame_seg_map[index + 1] = mbmi->segment_id;
+        if (mb_row + 1 < cm->mb_rows) {
+          cm->last_frame_seg_map[index + cm->mb_cols] = mbmi->segment_id;
+          if (mb_col + 1 < cm->mb_cols)
+            cm->last_frame_seg_map[index + cm->mb_cols + 1] = mbmi->segment_id;
+        }
+      } else
+#endif
+      {
+        cm->last_frame_seg_map[index] = mbmi->segment_id;
+      }
+    } else {
+#if CONFIG_SUPERBLOCKS
+      if (mbmi->encoded_as_sb) {
+        mbmi->segment_id = cm->last_frame_seg_map[index];
+        if (mb_col < cm->mb_cols - 1)
+          mbmi->segment_id = mbmi->segment_id &&
+                             cm->last_frame_seg_map[index + 1];
+        if (mb_row < cm->mb_rows - 1) {
+          mbmi->segment_id = mbmi->segment_id &&
+                             cm->last_frame_seg_map[index + cm->mb_cols];
+          if (mb_col < cm->mb_cols - 1)
+            mbmi->segment_id = mbmi->segment_id &&
+                               cm->last_frame_seg_map[index + cm->mb_cols + 1];
+        }
+      } else
+#endif
+      {
+        mbmi->segment_id = cm->last_frame_seg_map[index];
+      }
+    }
+  } else {
+    // The encoder explicitly sets the segment_id to 0
+    // when segmentation is disabled
+    mbmi->segment_id = 0;
+  }
+}
+
+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];
+  int mb_to_left_edge;
+  int mb_to_right_edge;
+  int mb_to_top_edge;
+  int mb_to_bottom_edge;
+
+  mb_to_top_edge = xd->mb_to_top_edge;
+  mb_to_bottom_edge = xd->mb_to_bottom_edge;
+  mb_to_top_edge -= LEFT_TOP_MARGIN;
+  mb_to_bottom_edge += RIGHT_BOTTOM_MARGIN;
+  mbmi->need_to_clamp_mvs = 0;
+  mbmi->need_to_clamp_secondmv = 0;
+  mbmi->second_ref_frame = NONE;
+  /* 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
+   */
+  xd->mb_to_left_edge =
+    mb_to_left_edge = -((mb_col * 16) << 3);
+  mb_to_left_edge -= LEFT_TOP_MARGIN;
+
+#if CONFIG_SUPERBLOCKS
+  if (mi->mbmi.encoded_as_sb) {
+    xd->mb_to_right_edge =
+      mb_to_right_edge = ((pbi->common.mb_cols - 2 - mb_col) * 16) << 3;
+  } else {
+#endif
+    xd->mb_to_right_edge =
+      mb_to_right_edge = ((pbi->common.mb_cols - 1 - mb_col) * 16) << 3;
+#if CONFIG_SUPERBLOCKS
+  }
+#endif
+  mb_to_right_edge += RIGHT_BOTTOM_MARGIN;
+
+  // 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;
+
+  // 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_EOB) ||
+       (vp9_get_segdata(xd, mbmi->segment_id, SEG_LVL_EOB) != 0))) {
+    // 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 {
+    if (vp9_segfeature_active(xd,
+                              mbmi->segment_id, SEG_LVL_EOB) &&
+        (vp9_get_segdata(xd, mbmi->segment_id, SEG_LVL_EOB) == 0)) {
+      mbmi->mb_skip_coeff = 1;
+    } else
+      mbmi->mb_skip_coeff = 0;
+  }
+
+  // Read the reference frame
+  if (vp9_segfeature_active(xd, mbmi->segment_id, SEG_LVL_MODE)
+      && vp9_get_segdata(xd, mbmi->segment_id, SEG_LVL_MODE) < NEARESTMV)
+    mbmi->ref_frame = INTRA_FRAME;
+  else
+    mbmi->ref_frame = read_ref_frame(pbi, bc, mbmi->segment_id);
+
+  // 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];
+
+    int recon_y_stride, recon_yoffset;
+    int recon_uv_stride, recon_uvoffset;
+
+    {
+      int ref_fb_idx;
+      MV_REFERENCE_FRAME ref_frame = mbmi->ref_frame;
+
+      /* Select the appropriate reference frame for this MB */
+      if (ref_frame == LAST_FRAME)
+        ref_fb_idx = cm->lst_fb_idx;
+      else if (ref_frame == GOLDEN_FRAME)
+        ref_fb_idx = cm->gld_fb_idx;
+      else
+        ref_fb_idx = cm->alt_fb_idx;
+
+      recon_y_stride = cm->yv12_fb[ref_fb_idx].y_stride  ;
+      recon_uv_stride = cm->yv12_fb[ref_fb_idx].uv_stride;
+
+      recon_yoffset = (mb_row * recon_y_stride * 16) + (mb_col * 16);
+      recon_uvoffset = (mb_row * recon_uv_stride * 8) + (mb_col * 8);
+
+      xd->pre.y_buffer = cm->yv12_fb[ref_fb_idx].y_buffer + recon_yoffset;
+      xd->pre.u_buffer = cm->yv12_fb[ref_fb_idx].u_buffer + recon_uvoffset;
+      xd->pre.v_buffer = cm->yv12_fb[ref_fb_idx].v_buffer + recon_uvoffset;
+
+#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
+      vp9_find_mv_refs(xd, mi, prev_mi,
+                       ref_frame, mbmi->ref_mvs[ref_frame],
+                       cm->ref_frame_sign_bias);
+
+      vp9_find_best_ref_mvs(xd,
+                            xd->pre.y_buffer,
+                            recon_y_stride,
+                            mbmi->ref_mvs[ref_frame],
+                            &best_mv, &nearest, &nearby);
+
+      vp9_mv_ref_probs(&pbi->common, mv_ref_p,
+                       mbmi->mb_mode_context[ref_frame]);
+#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
+    }
+
+    // Is the segment level mode feature enabled for this segment
+    if (vp9_segfeature_active(xd, mbmi->segment_id, SEG_LVL_MODE)) {
+      mbmi->mode =
+        vp9_get_segdata(xd, mbmi->segment_id, SEG_LVL_MODE);
+    } else {
+#if CONFIG_SUPERBLOCKS
+      if (mbmi->encoded_as_sb) {
+        mbmi->mode = read_sb_mv_ref(bc, mv_ref_p);
+      } else
+#endif
+      mbmi->mode = read_mv_ref(bc, mv_ref_p);
+
+      vp9_accum_mv_refs(&pbi->common, mbmi->mode,
+                        mbmi->mb_mode_context[mbmi->ref_frame]);
+    }
+
+#if CONFIG_PRED_FILTER
+    if (mbmi->mode >= NEARESTMV && mbmi->mode < SPLITMV) {
+      // Is the prediction filter enabled
+      if (cm->pred_filter_mode == 2)
+        mbmi->pred_filter_enabled =
+          vp9_read(bc, cm->prob_pred_filter_off);
+      else
+        mbmi->pred_filter_enabled = cm->pred_filter_mode;
+    }
+#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;
+        /* Select the appropriate reference frame for this MB */
+        if (mbmi->second_ref_frame == LAST_FRAME)
+          second_ref_fb_idx = cm->lst_fb_idx;
+        else if (mbmi->second_ref_frame ==
+          GOLDEN_FRAME)
+          second_ref_fb_idx = cm->gld_fb_idx;
+        else
+          second_ref_fb_idx = cm->alt_fb_idx;
+
+        xd->second_pre.y_buffer =
+          cm->yv12_fb[second_ref_fb_idx].y_buffer + recon_yoffset;
+        xd->second_pre.u_buffer =
+          cm->yv12_fb[second_ref_fb_idx].u_buffer + recon_uvoffset;
+        xd->second_pre.v_buffer =
+          cm->yv12_fb[second_ref_fb_idx].v_buffer + recon_uvoffset;
+
+        vp9_find_mv_refs(xd, mi, prev_mi,
+                         mbmi->second_ref_frame,
+                         mbmi->ref_mvs[mbmi->second_ref_frame],
+                         cm->ref_frame_sign_bias);
+
+        vp9_find_best_ref_mvs(xd,
+                              xd->second_pre.y_buffer,
+                              recon_y_stride,
+                              mbmi->ref_mvs[mbmi->second_ref_frame],
+                              &best_mv_second,
+                              &nearest_second,
+                              &nearby_second);
+      }
+
+    } 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 = (MB_PREDICTION_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 = (MB_PREDICTION_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
+    }
+
+    mbmi->uv_mode = DC_PRED;
+    switch (mbmi->mode) {
+      case SPLITMV: {
+        const int s = mbmi->partitioning =
+                        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;
+        do { /* for each subset j */
+          int_mv leftmv, abovemv, second_leftmv, second_abovemv;
+          int_mv blockmv, secondmv;
+          int k;  /* first block in subset j */
+          int mv_contz;
+          int blockmode;
+
+          k = vp9_mbsplit_offset[s][j];
+
+          leftmv.as_int = left_block_mv(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(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:
+              read_nmv(bc, &blockmv.as_mv, &best_mv.as_mv, nmvc);
+              read_nmv_fp(bc, &blockmv.as_mv, &best_mv.as_mv, nmvc,
+                          xd->allow_high_precision_mv);
+              vp9_increment_nmv(&blockmv.as_mv, &best_mv.as_mv,
+                                &cm->fc.NMVcount, xd->allow_high_precision_mv);
+              blockmv.as_mv.row += best_mv.as_mv.row;
+              blockmv.as_mv.col += best_mv.as_mv.col;
+
+              if (mbmi->second_ref_frame > 0) {
+                read_nmv(bc, &secondmv.as_mv, &best_mv_second.as_mv, nmvc);
+                read_nmv_fp(bc, &secondmv.as_mv, &best_mv_second.as_mv, nmvc,
+                            xd->allow_high_precision_mv);
+                vp9_increment_nmv(&secondmv.as_mv, &best_mv_second.as_mv,
+                                  &cm->fc.NMVcount, xd->allow_high_precision_mv);
+                secondmv.as_mv.row += best_mv_second.as_mv.row;
+                secondmv.as_mv.col += best_mv_second.as_mv.col;
+              }
+#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". */
+            const unsigned char *fill_offset;
+            unsigned int fill_count = mbsplit_fill_count[s];
+
+            fill_offset = &mbsplit_fill_offset[s][(unsigned char)j * mbsplit_fill_count[s]];
+
+            do {
+              mi->bmi[ *fill_offset].as_mv.first.as_int = blockmv.as_int;
+              if (mbmi->second_ref_frame > 0)
+                mi->bmi[ *fill_offset].as_mv.second.as_int = secondmv.as_int;
+              fill_offset++;
+            } while (--fill_count);
+          }
+
+        } while (++j < num_p);
+      }
+
+      mv->as_int = mi->bmi[15].as_mv.first.as_int;
+      mbmi->mv[1].as_int = mi->bmi[15].as_mv.second.as_int;
+
+      break;  /* done with SPLITMV */
+
+      case NEARMV:
+        mv->as_int = nearby.as_int;
+        /* Clip "next_nearest" so that it does not extend to far out of image */
+        clamp_mv(mv, mb_to_left_edge, mb_to_right_edge,
+                 mb_to_top_edge, mb_to_bottom_edge);
+        if (mbmi->second_ref_frame > 0) {
+          mbmi->mv[1].as_int = nearby_second.as_int;
+          clamp_mv(&mbmi->mv[1], mb_to_left_edge, mb_to_right_edge,
+                   mb_to_top_edge, mb_to_bottom_edge);
+        }
+        break;
+
+      case NEARESTMV:
+        mv->as_int = nearest.as_int;
+        /* Clip "next_nearest" so that it does not extend to far out of image */
+        clamp_mv(mv, mb_to_left_edge, mb_to_right_edge,
+                 mb_to_top_edge, mb_to_bottom_edge);
+        if (mbmi->second_ref_frame > 0) {
+          mbmi->mv[1].as_int = nearest_second.as_int;
+          clamp_mv(&mbmi->mv[1], 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:
+
+#if CONFIG_NEW_MVREF
+        {
+          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_id_probs[ref_frame]);
+
+          best_mv.as_int = mbmi->ref_mvs[ref_frame][best_index].as_int;
+        }
+#endif
+
+        read_nmv(bc, &mv->as_mv, &best_mv.as_mv, nmvc);
+        read_nmv_fp(bc, &mv->as_mv, &best_mv.as_mv, nmvc,
+                    xd->allow_high_precision_mv);
+        vp9_increment_nmv(&mv->as_mv, &best_mv.as_mv, &cm->fc.NMVcount,
+                          xd->allow_high_precision_mv);
+
+        mv->as_mv.row += best_mv.as_mv.row;
+        mv->as_mv.col += best_mv.as_mv.col;
+
+        /* 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) {
+#if CONFIG_NEW_MVREF
+        {
+          int best_index;
+          MV_REFERENCE_FRAME ref_frame = mbmi->second_ref_frame;
+
+          // Encode the index of the choice.
+          best_index =
+            vp9_read_mv_ref_id(bc, xd->mb_mv_ref_id_probs[ref_frame]);
+          best_mv_second.as_int = mbmi->ref_mvs[ref_frame][best_index].as_int;
+        }
+#endif
+
+          read_nmv(bc, &mbmi->mv[1].as_mv, &best_mv_second.as_mv, nmvc);
+          read_nmv_fp(bc, &mbmi->mv[1].as_mv, &best_mv_second.as_mv, nmvc,
+                      xd->allow_high_precision_mv);
+          vp9_increment_nmv(&mbmi->mv[1].as_mv, &best_mv_second.as_mv,
+                            &cm->fc.NMVcount, xd->allow_high_precision_mv);
+          mbmi->mv[1].as_mv.row += best_mv_second.as_mv.row;
+          mbmi->mv[1].as_mv.col += best_mv_second.as_mv.col;
+          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 (vp9_segfeature_active(xd, mbmi->segment_id, SEG_LVL_MODE)) {
+      mbmi->mode = (MB_PREDICTION_MODE)
+                   vp9_get_segdata(xd, mbmi->segment_id, SEG_LVL_MODE);
+#if CONFIG_SUPERBLOCKS
+    } else if (mbmi->encoded_as_sb) {
+      mbmi->mode = (MB_PREDICTION_MODE)
+                   read_sb_ymode(bc, pbi->common.fc.sb_ymode_prob);
+      pbi->common.fc.sb_ymode_counts[mbmi->mode]++;
+#endif
+    } else {
+      mbmi->mode = (MB_PREDICTION_MODE)
+                   read_ymode(bc, pbi->common.fc.ymode_prob);
+      pbi->common.fc.ymode_counts[mbmi->mode]++;
+    }
+#if CONFIG_COMP_INTRA_PRED
+    mbmi->second_mode = (MB_PREDICTION_MODE)(DC_PRED - 1);
+#endif
+
+    // If MB mode is BPRED read the block modes
+    if (mbmi->mode == B_PRED) {
+      int j = 0;
+#if CONFIG_COMP_INTRA_PRED
+      int use_comp_pred = vp9_read(bc, DEFAULT_COMP_INTRA_PROB);
+#endif
+      do {
+        int m;
+        m = mi->bmi[j].as_mode.first = (B_PREDICTION_MODE)
+            read_bmode(bc, pbi->common.fc.bmode_prob);
+#if CONFIG_NEWBINTRAMODES
+        if (m == B_CONTEXT_PRED) m -= CONTEXT_PRED_REPLACEMENTS;
+#endif
+        pbi->common.fc.bmode_counts[m]++;
+#if CONFIG_COMP_INTRA_PRED
+        if (use_comp_pred) {
+          mi->bmi[j].as_mode.second = (B_PREDICTION_MODE)read_bmode(bc, pbi->common.fc.bmode_prob);
+        } else {
+          mi->bmi[j].as_mode.second = (B_PREDICTION_MODE)(B_DC_PRED - 1);
+        }
+#endif
+      } while (++j < 16);
+    }
+
+    if (mbmi->mode == I8X8_PRED) {
+      int i;
+      int mode8x8;
+      for (i = 0; i < 4; i++) {
+        int ib = vp9_i8x8_block[i];
+        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]++;
+#if CONFIG_COMP_INTRA_PRED
+        mi->bmi[ib + 0].as_mode.second = (MB_PREDICTION_MODE)(DC_PRED - 1);
+        mi->bmi[ib + 1].as_mode.second = (MB_PREDICTION_MODE)(DC_PRED - 1);
+        mi->bmi[ib + 4].as_mode.second = (MB_PREDICTION_MODE)(DC_PRED - 1);
+        mi->bmi[ib + 5].as_mode.second = (MB_PREDICTION_MODE)(DC_PRED - 1);
+#endif
+      }
+    } else {
+      mbmi->uv_mode = (MB_PREDICTION_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 CONFIG_COMP_INTRA_PRED
+    mbmi->second_uv_mode = (MB_PREDICTION_MODE)(DC_PRED - 1);
+#endif
+  }
+
+  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]);
+  } 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_prob)vp9_read_literal(bc, 8);
+  }
+
+  mb_mode_mv_init(pbi, bc);
+}
+void vp9_decode_mb_mode_mv(VP9D_COMP* const pbi,
+                           MACROBLOCKD* const xd,
+                           int mb_row,
+                           int mb_col,
+                           BOOL_DECODER* const bc) {
+  MODE_INFO *mi = xd->mode_info_context;
+  MODE_INFO *prev_mi = xd->prev_mode_info_context;
+
+  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);
+}