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 "treereader.h"
  #include "vp8/common/entropymv.h"
  #include "vp8/common/entropymode.h"
  #include "onyxd_int.h"
  #include "vp8/common/findnearmv.h"
  
  #if CONFIG_DEBUG
  #include <assert.h>
  #endif
  static B_PREDICTION_MODE read_bmode(vp8_reader *bc, const vp8_prob *p)
  {
      const int i = vp8_treed_read(bc, vp8_bmode_tree, p);
  
      return (B_PREDICTION_MODE)i;
  }
  
  static MB_PREDICTION_MODE read_ymode(vp8_reader *bc, const vp8_prob *p)
  {
      const int i = vp8_treed_read(bc, vp8_ymode_tree, p);
  
      return (MB_PREDICTION_MODE)i;
  }
  
  static MB_PREDICTION_MODE read_kf_ymode(vp8_reader *bc, const vp8_prob *p)
  {
      const int i = vp8_treed_read(bc, vp8_kf_ymode_tree, p);
  
      return (MB_PREDICTION_MODE)i;
  }
  
  static MB_PREDICTION_MODE read_uv_mode(vp8_reader *bc, const vp8_prob *p)
  {
      const int i = vp8_treed_read(bc, vp8_uv_mode_tree, p);
  
      return (MB_PREDICTION_MODE)i;
  }
  
  static void read_kf_modes(VP8D_COMP *pbi, MODE_INFO *mi)
  {
      vp8_reader *const bc = & pbi->mbc[8];
      const int mis = pbi->common.mode_info_stride;
  
      mi->mbmi.ref_frame = INTRA_FRAME;
      mi->mbmi.mode = read_kf_ymode(bc, vp8_kf_ymode_prob);
  
      if (mi->mbmi.mode == B_PRED)
      {
          int i = 0;
          mi->mbmi.is_4x4 = 1;
  
          do
          {
              const B_PREDICTION_MODE A = above_block_mode(mi, i, mis);
              const B_PREDICTION_MODE L = left_block_mode(mi, i);
  
              mi->bmi[i].as_mode =
                  read_bmode(bc, vp8_kf_bmode_prob [A] [L]);
          }
          while (++i < 16);
      }
  
      mi->mbmi.uv_mode = read_uv_mode(bc, vp8_kf_uv_mode_prob);
  }
  
  static int read_mvcomponent(vp8_reader *r, const MV_CONTEXT *mvc)
  {
      const vp8_prob *const p = (const vp8_prob *) mvc;
      int x = 0;
  
      if (vp8_read(r, p [mvpis_short]))  /* Large */
      {
          int i = 0;
  
          do
          {
              x += vp8_read(r, p [MVPbits + i]) << i;
          }
          while (++i < 3);
  
          i = mvlong_width - 1;  /* Skip bit 3, which is sometimes implicit */
  
          do
          {
              x += vp8_read(r, p [MVPbits + i]) << i;
          }
          while (--i > 3);
  
          if (!(x & 0xFFF0)  ||  vp8_read(r, p [MVPbits + 3]))
              x += 8;
      }
      else   /* small */
          x = vp8_treed_read(r, vp8_small_mvtree, p + MVPshort);
  
      if (x  &&  vp8_read(r, p [MVPsign]))
          x = -x;
  
      return x;
  }
  
  static void read_mv(vp8_reader *r, MV *mv, const MV_CONTEXT *mvc)
  {
      mv->row = (short)(read_mvcomponent(r,   mvc) * 2);
      mv->col = (short)(read_mvcomponent(r, ++mvc) * 2);
  }
  
  
  static void read_mvcontexts(vp8_reader *bc, MV_CONTEXT *mvc)
  {
      int i = 0;
  
      do
      {
          const vp8_prob *up = vp8_mv_update_probs[i].prob;
          vp8_prob *p = (vp8_prob *)(mvc + i);
          vp8_prob *const pstop = p + MVPcount;
  
          do
          {
              if (vp8_read(bc, *up++))
              {
                  const vp8_prob x = (vp8_prob)vp8_read_literal(bc, 7);
  
                  *p = x ? x << 1 : 1;
              }
          }
          while (++p < pstop);
      }
      while (++i < 2);
  }
  
  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 mb_mode_mv_init(VP8D_COMP *pbi)
  {
      vp8_reader *const bc = & pbi->mbc[8];
      MV_CONTEXT *const mvc = pbi->common.fc.mvc;
  
  #if CONFIG_ERROR_CONCEALMENT
      /* Default is that no macroblock is corrupt, therefore we initialize
       * mvs_corrupt_from_mb to something very big, which we can be sure is
       * outside the frame. */
      pbi->mvs_corrupt_from_mb = UINT_MAX;
  #endif
      /* Read the mb_no_coeff_skip flag */
      pbi->common.mb_no_coeff_skip = (int)vp8_read_bit(bc);
  
      pbi->prob_skip_false = 0;
      if (pbi->common.mb_no_coeff_skip)
          pbi->prob_skip_false = (vp8_prob)vp8_read_literal(bc, 8);
  
      if(pbi->common.frame_type != KEY_FRAME)
      {
          pbi->prob_intra = (vp8_prob)vp8_read_literal(bc, 8);
          pbi->prob_last  = (vp8_prob)vp8_read_literal(bc, 8);
          pbi->prob_gf    = (vp8_prob)vp8_read_literal(bc, 8);
  
          if (vp8_read_bit(bc))
          {
              int i = 0;
  
              do
              {
                  pbi->common.fc.ymode_prob[i] =
                      (vp8_prob) vp8_read_literal(bc, 8);
              }
              while (++i < 4);
          }
  
          if (vp8_read_bit(bc))
          {
              int i = 0;
  
              do
              {
                  pbi->common.fc.uv_mode_prob[i] =
                      (vp8_prob) vp8_read_literal(bc, 8);
              }
              while (++i < 3);
          }
  
          read_mvcontexts(bc, mvc);
      }
  }
  
  const vp8_prob vp8_sub_mv_ref_prob3 [8][VP8_SUBMVREFS-1] =
  {
      { 147, 136, 18 },   /* SUBMVREF_NORMAL          */
      { 223, 1  , 34 },   /* SUBMVREF_LEFT_ABOVE_SAME */
      { 106, 145, 1  },   /* SUBMVREF_LEFT_ZED        */
      { 208, 1  , 1  },   /* SUBMVREF_LEFT_ABOVE_ZED  */
      { 179, 121, 1  },   /* SUBMVREF_ABOVE_ZED       */
      { 223, 1  , 34 },   /* SUBMVREF_LEFT_ABOVE_SAME */
      { 179, 121, 1  },   /* SUBMVREF_ABOVE_ZED       */
      { 208, 1  , 1  }    /* SUBMVREF_LEFT_ABOVE_ZED  */
  };
  
  static
  const vp8_prob * get_sub_mv_ref_prob(const int left, const int above)
  {
      int lez = (left == 0);
      int aez = (above == 0);
      int lea = (left == above);
      const vp8_prob * prob;
  
      prob = vp8_sub_mv_ref_prob3[(aez << 2) |
                                  (lez << 1) |
                                  (lea)];
  
      return prob;
  }
  
  static void decode_split_mv(vp8_reader *const bc, MODE_INFO *mi,
                          const MODE_INFO *left_mb, const MODE_INFO *above_mb,
                          MB_MODE_INFO *mbmi, int_mv best_mv,
                          MV_CONTEXT *const mvc, int mb_to_left_edge,
                          int mb_to_right_edge, int mb_to_top_edge,
                          int mb_to_bottom_edge)
  {
      int s;      /* split configuration (16x8, 8x16, 8x8, 4x4) */
      int num_p;  /* number of partitions in the split configuration
                    (see vp8_mbsplit_count) */
      int j = 0;
  
      s = 3;
      num_p = 16;
      if( vp8_read(bc, 110) )
      {
          s = 2;
          num_p = 4;
          if( vp8_read(bc, 111) )
          {
              s = vp8_read(bc, 150);
              num_p = 2;
          }
      }
  
      do  /* for each subset j */
      {
          int_mv leftmv, abovemv;
          int_mv blockmv;
          int k;  /* first block in subset j */
  
          const vp8_prob *prob;
          k = vp8_mbsplit_offset[s][j];
  
          if (!(k & 3))
          {
              /* On L edge, get from MB to left of us */
              if(left_mb->mbmi.mode != SPLITMV)
                  leftmv.as_int =  left_mb->mbmi.mv.as_int;
              else
                  leftmv.as_int =  (left_mb->bmi + k + 4 - 1)->mv.as_int;
          }
          else
              leftmv.as_int =  (mi->bmi + k - 1)->mv.as_int;
  
          if (!(k >> 2))
          {
              /* On top edge, get from MB above us */
              if(above_mb->mbmi.mode != SPLITMV)
                  abovemv.as_int =  above_mb->mbmi.mv.as_int;
              else
                  abovemv.as_int =  (above_mb->bmi + k + 16 - 4)->mv.as_int;
          }
          else
              abovemv.as_int = (mi->bmi + k - 4)->mv.as_int;
  
          prob = get_sub_mv_ref_prob(leftmv.as_int, abovemv.as_int);
  
          if( vp8_read(bc, prob[0]) )
          {
              if( vp8_read(bc, prob[1]) )
              {
                  blockmv.as_int = 0;
                  if( vp8_read(bc, prob[2]) )
                  {
                      blockmv.as_mv.row = read_mvcomponent(bc, &mvc[0]) * 2;
                      blockmv.as_mv.row += best_mv.as_mv.row;
                      blockmv.as_mv.col = read_mvcomponent(bc, &mvc[1]) * 2;
                      blockmv.as_mv.col += best_mv.as_mv.col;
                  }
              }
              else
              {
                  blockmv.as_int = abovemv.as_int;
              }
          }
          else
          {
              blockmv.as_int = leftmv.as_int;
          }
  
          mbmi->need_to_clamp_mvs |= vp8_check_mv_bounds(&blockmv,
                                                    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].mv.as_int = blockmv.as_int;
                  fill_offset++;
              }while (--fill_count);
          }
  
      }
      while (++j < num_p);
  
      mbmi->partitioning = s;
  }
  
  static void read_mb_modes_mv(VP8D_COMP *pbi, MODE_INFO *mi, MB_MODE_INFO *mbmi)
  {
      vp8_reader *const bc = & pbi->mbc[8];
      mbmi->ref_frame = (MV_REFERENCE_FRAME) vp8_read(bc, pbi->prob_intra);
      if (mbmi->ref_frame)    /* inter MB */
      {
          enum {CNT_INTRA, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV};
          int cnt[4];
          int *cntx = cnt;
          int_mv near_mvs[4];
          int_mv *nmv = near_mvs;
          const int mis = pbi->mb.mode_info_stride;
          const MODE_INFO *above = mi - mis;
          const MODE_INFO *left = mi - 1;
          const MODE_INFO *aboveleft = above - 1;
          int *ref_frame_sign_bias = pbi->common.ref_frame_sign_bias;
  
          mbmi->need_to_clamp_mvs = 0;
  
          if (vp8_read(bc, pbi->prob_last))
          {
              mbmi->ref_frame =
                  (MV_REFERENCE_FRAME)((int)(2 + vp8_read(bc, pbi->prob_gf)));
          }
  
          /* Zero accumulators */
          nmv[0].as_int = nmv[1].as_int = nmv[2].as_int = 0;
          cnt[0] = cnt[1] = cnt[2] = cnt[3] = 0;
  
          /* Process above */
          if (above->mbmi.ref_frame != INTRA_FRAME)
          {
              if (above->mbmi.mv.as_int)
              {
                  (++nmv)->as_int = above->mbmi.mv.as_int;
                  mv_bias(ref_frame_sign_bias[above->mbmi.ref_frame],
                          mbmi->ref_frame, nmv, ref_frame_sign_bias);
                  ++cntx;
              }
  
              *cntx += 2;
          }
  
          /* Process left */
          if (left->mbmi.ref_frame != INTRA_FRAME)
          {
              if (left->mbmi.mv.as_int)
              {
                  int_mv this_mv;
  
                  this_mv.as_int = left->mbmi.mv.as_int;
                  mv_bias(ref_frame_sign_bias[left->mbmi.ref_frame],
                          mbmi->ref_frame, &this_mv, ref_frame_sign_bias);
  
                  if (this_mv.as_int != nmv->as_int)
                  {
                      (++nmv)->as_int = this_mv.as_int;
                      ++cntx;
                  }
  
                  *cntx += 2;
              }
              else
                  cnt[CNT_INTRA] += 2;
          }
  
          /* Process above left */
          if (aboveleft->mbmi.ref_frame != INTRA_FRAME)
          {
              if (aboveleft->mbmi.mv.as_int)
              {
                  int_mv this_mv;
  
                  this_mv.as_int = aboveleft->mbmi.mv.as_int;
                  mv_bias(ref_frame_sign_bias[aboveleft->mbmi.ref_frame],
                          mbmi->ref_frame, &this_mv, ref_frame_sign_bias);
  
                  if (this_mv.as_int != nmv->as_int)
                  {
                      (++nmv)->as_int = this_mv.as_int;
                      ++cntx;
                  }
  
                  *cntx += 1;
              }
              else
                  cnt[CNT_INTRA] += 1;
          }
  
          if( vp8_read(bc, vp8_mode_contexts [cnt[CNT_INTRA]] [0]) )
          {
  
              /* If we have three distinct MV's ... */
              /* See if above-left MV can be merged with NEAREST */
              cnt[CNT_NEAREST] += ( (cnt[CNT_SPLITMV] > 0) &
                  (nmv->as_int == near_mvs[CNT_NEAREST].as_int));
  
              /* Swap near and nearest if necessary */
              if (cnt[CNT_NEAR] > cnt[CNT_NEAREST])
              {
                  int tmp;
                  tmp = cnt[CNT_NEAREST];
                  cnt[CNT_NEAREST] = cnt[CNT_NEAR];
                  cnt[CNT_NEAR] = tmp;
                  tmp = near_mvs[CNT_NEAREST].as_int;
                  near_mvs[CNT_NEAREST].as_int = near_mvs[CNT_NEAR].as_int;
                  near_mvs[CNT_NEAR].as_int = tmp;
              }
  
              if( vp8_read(bc, vp8_mode_contexts [cnt[CNT_NEAREST]] [1]) )
              {
  
                  if( vp8_read(bc, vp8_mode_contexts [cnt[CNT_NEAR]] [2]) )
                  {
                      int mb_to_top_edge;
                      int mb_to_bottom_edge;
                      int mb_to_left_edge;
                      int mb_to_right_edge;
                      MV_CONTEXT *const mvc = pbi->common.fc.mvc;
                      int near_index;
  
                      mb_to_top_edge = pbi->mb.mb_to_top_edge;
                      mb_to_bottom_edge = pbi->mb.mb_to_bottom_edge;
                      mb_to_top_edge -= LEFT_TOP_MARGIN;
                      mb_to_bottom_edge += RIGHT_BOTTOM_MARGIN;
                      mb_to_right_edge = pbi->mb.mb_to_right_edge;
                      mb_to_right_edge += RIGHT_BOTTOM_MARGIN;
                      mb_to_left_edge = pbi->mb.mb_to_left_edge;
                      mb_to_left_edge -= LEFT_TOP_MARGIN;
  
                      /* Use near_mvs[0] to store the "best" MV */
                      near_index = CNT_INTRA +
                          (cnt[CNT_NEAREST] >= cnt[CNT_INTRA]);
  
                      vp8_clamp_mv2(&near_mvs[near_index], &pbi->mb);
  
                      cnt[CNT_SPLITMV] = ((above->mbmi.mode == SPLITMV)
                                          + (left->mbmi.mode == SPLITMV)) * 2
                                         + (aboveleft->mbmi.mode == SPLITMV);
  
                      if( vp8_read(bc, vp8_mode_contexts [cnt[CNT_SPLITMV]] [3]) )
                      {
                          decode_split_mv(bc, mi, left, above,
                                                      mbmi,
                                                      near_mvs[near_index],
                                                      mvc, mb_to_left_edge,
                                                      mb_to_right_edge,
                                                      mb_to_top_edge,
                                                      mb_to_bottom_edge);
                          mbmi->mv.as_int = mi->bmi[15].mv.as_int;
                          mbmi->mode =  SPLITMV;
                          mbmi->is_4x4 = 1;
                      }
                      else
                      {
                          int_mv *const mbmi_mv = & mbmi->mv;
                          read_mv(bc, &mbmi_mv->as_mv, (const MV_CONTEXT *) mvc);
                          mbmi_mv->as_mv.row += near_mvs[near_index].as_mv.row;
                          mbmi_mv->as_mv.col += near_mvs[near_index].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 =
                              vp8_check_mv_bounds(mbmi_mv, mb_to_left_edge,
                                                  mb_to_right_edge,
                                                  mb_to_top_edge,
                                                  mb_to_bottom_edge);
                          mbmi->mode =  NEWMV;
                      }
                  }
                  else
                  {
                      mbmi->mode =  NEARMV;
                      mbmi->mv.as_int = near_mvs[CNT_NEAR].as_int;
                      vp8_clamp_mv2(&mbmi->mv, &pbi->mb);
                  }
              }
              else
              {
                  mbmi->mode =  NEARESTMV;
                  mbmi->mv.as_int = near_mvs[CNT_NEAREST].as_int;
                  vp8_clamp_mv2(&mbmi->mv, &pbi->mb);
              }
          }
          else
          {
              mbmi->mode =  ZEROMV;
              mbmi->mv.as_int = 0;
          }
  
  #if CONFIG_ERROR_CONCEALMENT
          if(pbi->ec_enabled && (mbmi->mode != SPLITMV))
          {
              mi->bmi[ 0].mv.as_int =
              mi->bmi[ 1].mv.as_int =
              mi->bmi[ 2].mv.as_int =
              mi->bmi[ 3].mv.as_int =
              mi->bmi[ 4].mv.as_int =
              mi->bmi[ 5].mv.as_int =
              mi->bmi[ 6].mv.as_int =
              mi->bmi[ 7].mv.as_int =
              mi->bmi[ 8].mv.as_int =
              mi->bmi[ 9].mv.as_int =
              mi->bmi[10].mv.as_int =
              mi->bmi[11].mv.as_int =
              mi->bmi[12].mv.as_int =
              mi->bmi[13].mv.as_int =
              mi->bmi[14].mv.as_int =
              mi->bmi[15].mv.as_int = mbmi->mv.as_int;
          }
  #endif
      }
      else
      {
          /* required for left and above block mv */
          mbmi->mv.as_int = 0;
  
          /* MB is intra coded */
          if ((mbmi->mode = read_ymode(bc, pbi->common.fc.ymode_prob)) == B_PRED)
          {
              int j = 0;
              mbmi->is_4x4 = 1;
              do
              {
                  mi->bmi[j].as_mode = read_bmode(bc, pbi->common.fc.bmode_prob);
              }
              while (++j < 16);
          }
  
          mbmi->uv_mode = read_uv_mode(bc, pbi->common.fc.uv_mode_prob);
      }
  
  }
  
  static void read_mb_features(vp8_reader *r, MB_MODE_INFO *mi, MACROBLOCKD *x)
  {
      /* Is segmentation enabled */
      if (x->segmentation_enabled && x->update_mb_segmentation_map)
      {
          /* If so then read the segment id. */
          if (vp8_read(r, x->mb_segment_tree_probs[0]))
              mi->segment_id =
                  (unsigned char)(2 + vp8_read(r, x->mb_segment_tree_probs[2]));
          else
              mi->segment_id =
                  (unsigned char)(vp8_read(r, x->mb_segment_tree_probs[1]));
      }
  }
  
  static void decode_mb_mode_mvs(VP8D_COMP *pbi, MODE_INFO *mi)
  {
      /* Read the Macroblock segmentation map if it is being updated explicitly
       * this frame (reset to 0 above by default)
       * By default on a key frame reset all MBs to segment 0
       */
      if (pbi->mb.update_mb_segmentation_map)
          read_mb_features(&pbi->mbc[8], &mi->mbmi, &pbi->mb);
      else if(pbi->common.frame_type == KEY_FRAME)
          mi->mbmi.segment_id = 0;
  
      /* Read the macroblock coeff skip flag if this feature is in use,
       * else default to 0 */
      if (pbi->common.mb_no_coeff_skip)
          mi->mbmi.mb_skip_coeff = vp8_read(&pbi->mbc[8], pbi->prob_skip_false);
      else
          mi->mbmi.mb_skip_coeff = 0;
  
      mi->mbmi.is_4x4 = 0;
      if(pbi->common.frame_type == KEY_FRAME)
          read_kf_modes(pbi, mi);
      else
          read_mb_modes_mv(pbi, mi, &mi->mbmi);
  
  }
  
  void vp8_decode_mode_mvs(VP8D_COMP *pbi)
  {
      MODE_INFO *mi = pbi->common.mi;
      int mb_row = -1;
      int mb_to_right_edge_start;
  
      mb_mode_mv_init(pbi);
  
      pbi->mb.mb_to_top_edge = 0;
      pbi->mb.mb_to_bottom_edge = ((pbi->common.mb_rows - 1) * 16) << 3;
      mb_to_right_edge_start = ((pbi->common.mb_cols - 1) * 16) << 3;
  
      while (++mb_row < pbi->common.mb_rows)
      {
          int mb_col = -1;
  
          pbi->mb.mb_to_left_edge =  0;
          pbi->mb.mb_to_right_edge = mb_to_right_edge_start;
  
          while (++mb_col < pbi->common.mb_cols)
          {
  #if CONFIG_ERROR_CONCEALMENT
              int mb_num = mb_row * pbi->common.mb_cols + mb_col;
  #endif
  
              decode_mb_mode_mvs(pbi, mi);
  
  #if CONFIG_ERROR_CONCEALMENT
              /* look for corruption. set mvs_corrupt_from_mb to the current
               * mb_num if the frame is corrupt from this macroblock. */
              if (vp8dx_bool_error(&pbi->mbc[8]) && mb_num <
                  (int)pbi->mvs_corrupt_from_mb)
              {
                  pbi->mvs_corrupt_from_mb = mb_num;
                  /* no need to continue since the partition is corrupt from
                   * here on.
                   */
                  return;
              }
  #endif
  
              pbi->mb.mb_to_left_edge -= (16 << 3);
              pbi->mb.mb_to_right_edge -= (16 << 3);
              mi++;       /* next macroblock */
          }
          pbi->mb.mb_to_top_edge -= (16 << 3);
          pbi->mb.mb_to_bottom_edge -= (16 << 3);
  
          mi++;           /* skip left predictor each row */
      }
  }
  