The Tor Browser: media/libvpx/vp9/decoder/vp9_decodemv.c@ac0c01689b40 (annotated)

media/libvpx/vp9/decoder/vp9_decodemv.c@ac0c01689b40 (annotated)

media/libvpx/vp9/decoder/vp9_decodemv.c

Thu, 15 Jan 2015 15:59:08 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:59:08 +0100
branch: TOR_BUG_9701
changeset 10: ac0c01689b40
permissions: -rw-r--r--

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /*
   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 <assert.h>
 #include "vp9/common/vp9_common.h"
 #include "vp9/common/vp9_entropy.h"
 #include "vp9/common/vp9_entropymode.h"
 #include "vp9/common/vp9_entropymv.h"
 #include "vp9/common/vp9_findnearmv.h"
 #include "vp9/common/vp9_mvref_common.h"
 #include "vp9/common/vp9_pred_common.h"
 #include "vp9/common/vp9_reconinter.h"
 #include "vp9/common/vp9_seg_common.h"
 #include "vp9/decoder/vp9_decodemv.h"
 #include "vp9/decoder/vp9_decodframe.h"
 #include "vp9/decoder/vp9_onyxd_int.h"
 #include "vp9/decoder/vp9_treereader.h"
 static MB_PREDICTION_MODE read_intra_mode(vp9_reader *r, const vp9_prob *p) {
   return (MB_PREDICTION_MODE)treed_read(r, vp9_intra_mode_tree, p);
 }
 static MB_PREDICTION_MODE read_intra_mode_y(VP9_COMMON *cm, vp9_reader *r,
                                             int size_group) {
   const MB_PREDICTION_MODE y_mode = read_intra_mode(r,
                                         cm->fc.y_mode_prob[size_group]);
   if (!cm->frame_parallel_decoding_mode)
     ++cm->counts.y_mode[size_group][y_mode];
   return y_mode;
 }
 static MB_PREDICTION_MODE read_intra_mode_uv(VP9_COMMON *cm, vp9_reader *r,
                                              MB_PREDICTION_MODE y_mode) {
   const MB_PREDICTION_MODE uv_mode = read_intra_mode(r,
                                          cm->fc.uv_mode_prob[y_mode]);
   if (!cm->frame_parallel_decoding_mode)
     ++cm->counts.uv_mode[y_mode][uv_mode];
   return uv_mode;
 }
 static MB_PREDICTION_MODE read_inter_mode(VP9_COMMON *cm, vp9_reader *r,
                                           int ctx) {
   const int mode = treed_read(r, vp9_inter_mode_tree,
                               cm->fc.inter_mode_probs[ctx]);
   if (!cm->frame_parallel_decoding_mode)
     ++cm->counts.inter_mode[ctx][mode];
   return NEARESTMV + mode;
 }
 static int read_segment_id(vp9_reader *r, const struct segmentation *seg) {
   return treed_read(r, vp9_segment_tree, seg->tree_probs);
 }
 static TX_SIZE read_selected_tx_size(VP9_COMMON *cm, MACROBLOCKD *xd,
                                      TX_SIZE max_tx_size, vp9_reader *r) {
   const int ctx = vp9_get_pred_context_tx_size(xd);
   const vp9_prob *tx_probs = get_tx_probs(max_tx_size, ctx, &cm->fc.tx_probs);
   TX_SIZE tx_size = vp9_read(r, tx_probs[0]);
   if (tx_size != TX_4X4 && max_tx_size >= TX_16X16) {
     tx_size += vp9_read(r, tx_probs[1]);
     if (tx_size != TX_8X8 && max_tx_size >= TX_32X32)
       tx_size += vp9_read(r, tx_probs[2]);
   }
   if (!cm->frame_parallel_decoding_mode)
     ++get_tx_counts(max_tx_size, ctx, &cm->counts.tx)[tx_size];
   return tx_size;
 }
 static TX_SIZE read_tx_size(VP9_COMMON *cm, MACROBLOCKD *xd, TX_MODE tx_mode,
                             BLOCK_SIZE bsize, int allow_select, vp9_reader *r) {
   const TX_SIZE max_tx_size = max_txsize_lookup[bsize];
   if (allow_select && tx_mode == TX_MODE_SELECT && bsize >= BLOCK_8X8)
     return read_selected_tx_size(cm, xd, max_tx_size, r);
   else
     return MIN(max_tx_size, tx_mode_to_biggest_tx_size[tx_mode]);
 }
 static void set_segment_id(VP9_COMMON *cm, BLOCK_SIZE bsize,
                            int mi_row, int mi_col, int segment_id) {
   const int mi_offset = mi_row * cm->mi_cols + mi_col;
   const int bw = num_8x8_blocks_wide_lookup[bsize];
   const int bh = num_8x8_blocks_high_lookup[bsize];
   const int xmis = MIN(cm->mi_cols - mi_col, bw);
   const int ymis = MIN(cm->mi_rows - mi_row, bh);
   int x, y;
   assert(segment_id >= 0 && segment_id < MAX_SEGMENTS);
   for (y = 0; y < ymis; y++)
     for (x = 0; x < xmis; x++)
       cm->last_frame_seg_map[mi_offset + y * cm->mi_cols + x] = segment_id;
 }
 static int read_intra_segment_id(VP9_COMMON *const cm, MACROBLOCKD *const xd,
                                  int mi_row, int mi_col,
                                  vp9_reader *r) {
   struct segmentation *const seg = &cm->seg;
   const BLOCK_SIZE bsize = xd->mi_8x8[0]->mbmi.sb_type;
   int segment_id;
   if (!seg->enabled)
     return 0;  // Default for disabled segmentation
   if (!seg->update_map)
     return 0;
   segment_id = read_segment_id(r, seg);
   set_segment_id(cm, bsize, mi_row, mi_col, segment_id);
   return segment_id;
 }
 static int read_inter_segment_id(VP9_COMMON *const cm, MACROBLOCKD *const xd,
                                  int mi_row, int mi_col, vp9_reader *r) {
   struct segmentation *const seg = &cm->seg;
   const BLOCK_SIZE bsize = xd->mi_8x8[0]->mbmi.sb_type;
   int pred_segment_id, segment_id;
   if (!seg->enabled)
     return 0;  // Default for disabled segmentation
   pred_segment_id = vp9_get_segment_id(cm, cm->last_frame_seg_map,
                                        bsize, mi_row, mi_col);
   if (!seg->update_map)
     return pred_segment_id;
   if (seg->temporal_update) {
     const vp9_prob pred_prob = vp9_get_pred_prob_seg_id(seg, xd);
     const int pred_flag = vp9_read(r, pred_prob);
     vp9_set_pred_flag_seg_id(xd, pred_flag);
     segment_id = pred_flag ? pred_segment_id
                            : read_segment_id(r, seg);
   } else {
     segment_id = read_segment_id(r, seg);
   }
   set_segment_id(cm, bsize, mi_row, mi_col, segment_id);
   return segment_id;
 }
 static int read_skip_coeff(VP9_COMMON *cm, const MACROBLOCKD *xd,
                            int segment_id, vp9_reader *r) {
   if (vp9_segfeature_active(&cm->seg, segment_id, SEG_LVL_SKIP)) {
     return 1;
   } else {
     const int ctx = vp9_get_pred_context_mbskip(xd);
     const int skip = vp9_read(r, cm->fc.mbskip_probs[ctx]);
     if (!cm->frame_parallel_decoding_mode)
       ++cm->counts.mbskip[ctx][skip];
     return skip;
   }
 }
 static void read_intra_frame_mode_info(VP9_COMMON *const cm,
                                        MACROBLOCKD *const xd,
                                        MODE_INFO *const m,
                                        int mi_row, int mi_col, vp9_reader *r) {
   MB_MODE_INFO *const mbmi = &m->mbmi;
   const BLOCK_SIZE bsize = mbmi->sb_type;
   const MODE_INFO *above_mi = xd->mi_8x8[-cm->mode_info_stride];
   const MODE_INFO *left_mi  = xd->left_available ? xd->mi_8x8[-1] : NULL;
   mbmi->segment_id = read_intra_segment_id(cm, xd, mi_row, mi_col, r);
   mbmi->skip_coeff = read_skip_coeff(cm, xd, mbmi->segment_id, r);
   mbmi->tx_size = read_tx_size(cm, xd, cm->tx_mode, bsize, 1, r);
   mbmi->ref_frame[0] = INTRA_FRAME;
   mbmi->ref_frame[1] = NONE;
   if (bsize >= BLOCK_8X8) {
     const MB_PREDICTION_MODE A = above_block_mode(m, above_mi, 0);
     const MB_PREDICTION_MODE L = left_block_mode(m, left_mi, 0);
     mbmi->mode = read_intra_mode(r, vp9_kf_y_mode_prob[A][L]);
   } else {
     // Only 4x4, 4x8, 8x4 blocks
     const int num_4x4_w = num_4x4_blocks_wide_lookup[bsize];  // 1 or 2
     const int num_4x4_h = num_4x4_blocks_high_lookup[bsize];  // 1 or 2
     int idx, idy;
     for (idy = 0; idy < 2; idy += num_4x4_h) {
       for (idx = 0; idx < 2; idx += num_4x4_w) {
         const int ib = idy * 2 + idx;
         const MB_PREDICTION_MODE A = above_block_mode(m, above_mi, ib);
         const MB_PREDICTION_MODE L = left_block_mode(m, left_mi, ib);
         const MB_PREDICTION_MODE b_mode = read_intra_mode(r,
                                               vp9_kf_y_mode_prob[A][L]);
         m->bmi[ib].as_mode = b_mode;
         if (num_4x4_h == 2)
           m->bmi[ib + 2].as_mode = b_mode;
         if (num_4x4_w == 2)
           m->bmi[ib + 1].as_mode = b_mode;
       }
     }
     mbmi->mode = m->bmi[3].as_mode;
   }
   mbmi->uv_mode = read_intra_mode(r, vp9_kf_uv_mode_prob[mbmi->mode]);
 }
 static int read_mv_component(vp9_reader *r,
                              const nmv_component *mvcomp, int usehp) {
   int mag, d, fr, hp;
   const int sign = vp9_read(r, mvcomp->sign);
   const int mv_class = treed_read(r, vp9_mv_class_tree, mvcomp->classes);
   const int class0 = mv_class == MV_CLASS_0;
   // Integer part
   if (class0) {
     d = treed_read(r, vp9_mv_class0_tree, mvcomp->class0);
   } else {
     int i;
     const 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;
   }
   // Fractional part
   fr = treed_read(r, vp9_mv_fp_tree,
                   class0 ? mvcomp->class0_fp[d] : mvcomp->fp);
   // High precision part (if hp is not used, the default value of the hp is 1)
   hp = usehp ? vp9_read(r, class0 ? mvcomp->class0_hp : mvcomp->hp)
              : 1;
   // Result
   mag = vp9_get_mv_mag(mv_class, (d << 3) | (fr << 1) | hp) + 1;
   return sign ? -mag : mag;
 }
 static INLINE void read_mv(vp9_reader *r, MV *mv, const MV *ref,
                            const nmv_context *ctx,
                            nmv_context_counts *counts, int allow_hp) {
   const MV_JOINT_TYPE j = treed_read(r, vp9_mv_joint_tree, ctx->joints);
   const int use_hp = allow_hp && vp9_use_mv_hp(ref);
   MV diff = {0, 0};
   if (mv_joint_vertical(j))
     diff.row = read_mv_component(r, &ctx->comps[0], use_hp);
   if (mv_joint_horizontal(j))
     diff.col = read_mv_component(r, &ctx->comps[1], use_hp);
   vp9_inc_mv(&diff, counts);
   mv->row = ref->row + diff.row;
   mv->col = ref->col + diff.col;
 }
 static COMPPREDMODE_TYPE read_reference_mode(VP9_COMMON *cm,
                                              const MACROBLOCKD *xd,
                                              vp9_reader *r) {
   const int ctx = vp9_get_pred_context_comp_inter_inter(cm, xd);
   const int mode = vp9_read(r, cm->fc.comp_inter_prob[ctx]);
   if (!cm->frame_parallel_decoding_mode)
     ++cm->counts.comp_inter[ctx][mode];
   return mode;  // SINGLE_PREDICTION_ONLY or COMP_PREDICTION_ONLY
 }
 // Read the referncence frame
 static void read_ref_frames(VP9_COMMON *const cm, MACROBLOCKD *const xd,
                             vp9_reader *r,
                             int segment_id, MV_REFERENCE_FRAME ref_frame[2]) {
   FRAME_CONTEXT *const fc = &cm->fc;
   FRAME_COUNTS *const counts = &cm->counts;
   if (vp9_segfeature_active(&cm->seg, segment_id, SEG_LVL_REF_FRAME)) {
     ref_frame[0] = vp9_get_segdata(&cm->seg, segment_id, SEG_LVL_REF_FRAME);
     ref_frame[1] = NONE;
   } else {
     const COMPPREDMODE_TYPE mode = (cm->comp_pred_mode == HYBRID_PREDICTION)
                                       ? read_reference_mode(cm, xd, r)
                                       : cm->comp_pred_mode;
     // FIXME(rbultje) I'm pretty sure this breaks segmentation ref frame coding
     if (mode == COMP_PREDICTION_ONLY) {
       const int idx = cm->ref_frame_sign_bias[cm->comp_fixed_ref];
       const int ctx = vp9_get_pred_context_comp_ref_p(cm, xd);
       const int bit = vp9_read(r, fc->comp_ref_prob[ctx]);
       if (!cm->frame_parallel_decoding_mode)
         ++counts->comp_ref[ctx][bit];
       ref_frame[idx] = cm->comp_fixed_ref;
       ref_frame[!idx] = cm->comp_var_ref[bit];
     } else if (mode == SINGLE_PREDICTION_ONLY) {
       const int ctx0 = vp9_get_pred_context_single_ref_p1(xd);
       const int bit0 = vp9_read(r, fc->single_ref_prob[ctx0][0]);
       if (!cm->frame_parallel_decoding_mode)
         ++counts->single_ref[ctx0][0][bit0];
       if (bit0) {
         const int ctx1 = vp9_get_pred_context_single_ref_p2(xd);
         const int bit1 = vp9_read(r, fc->single_ref_prob[ctx1][1]);
         if (!cm->frame_parallel_decoding_mode)
           ++counts->single_ref[ctx1][1][bit1];
         ref_frame[0] = bit1 ? ALTREF_FRAME : GOLDEN_FRAME;
       } else {
         ref_frame[0] = LAST_FRAME;
       }
       ref_frame[1] = NONE;
     } else {
       assert(!"Invalid prediction mode.");
     }
   }
 }
 static INLINE INTERPOLATION_TYPE read_switchable_filter_type(
     VP9_COMMON *const cm, MACROBLOCKD *const xd, vp9_reader *r) {
   const int ctx = vp9_get_pred_context_switchable_interp(xd);
   const int type = treed_read(r, vp9_switchable_interp_tree,
                               cm->fc.switchable_interp_prob[ctx]);
   if (!cm->frame_parallel_decoding_mode)
     ++cm->counts.switchable_interp[ctx][type];
   return type;
 }
 static void read_intra_block_mode_info(VP9_COMMON *const cm, MODE_INFO *mi,
                                        vp9_reader *r) {
   MB_MODE_INFO *const mbmi = &mi->mbmi;
   const BLOCK_SIZE bsize = mi->mbmi.sb_type;
   mbmi->ref_frame[0] = INTRA_FRAME;
   mbmi->ref_frame[1] = NONE;
   if (bsize >= BLOCK_8X8) {
     mbmi->mode = read_intra_mode_y(cm, r, size_group_lookup[bsize]);
   } else {
      // Only 4x4, 4x8, 8x4 blocks
      const int num_4x4_w = num_4x4_blocks_wide_lookup[bsize];  // 1 or 2
      const int num_4x4_h = num_4x4_blocks_high_lookup[bsize];  // 1 or 2
      int idx, idy;
      for (idy = 0; idy < 2; idy += num_4x4_h) {
        for (idx = 0; idx < 2; idx += num_4x4_w) {
          const int ib = idy * 2 + idx;
          const int b_mode = read_intra_mode_y(cm, r, 0);
          mi->bmi[ib].as_mode = b_mode;
          if (num_4x4_h == 2)
            mi->bmi[ib + 2].as_mode = b_mode;
          if (num_4x4_w == 2)
            mi->bmi[ib + 1].as_mode = b_mode;
       }
     }
     mbmi->mode = mi->bmi[3].as_mode;
   }
   mbmi->uv_mode = read_intra_mode_uv(cm, r, mbmi->mode);
 }
 static INLINE int assign_mv(VP9_COMMON *cm, MB_PREDICTION_MODE mode,
                              int_mv mv[2], int_mv best_mv[2],
                              int_mv nearest_mv[2], int_mv near_mv[2],
                              int is_compound, int allow_hp, vp9_reader *r) {
   int i;
   int ret = 1;
   switch (mode) {
     case NEWMV: {
       nmv_context_counts *const mv_counts = cm->frame_parallel_decoding_mode ?
                                             NULL : &cm->counts.mv;
       read_mv(r, &mv[0].as_mv, &best_mv[0].as_mv,
               &cm->fc.nmvc, mv_counts, allow_hp);
       if (is_compound)
         read_mv(r, &mv[1].as_mv, &best_mv[1].as_mv,
                 &cm->fc.nmvc, mv_counts, allow_hp);
       for (i = 0; i < 1 + is_compound; ++i) {
         ret = ret && mv[i].as_mv.row < MV_UPP && mv[i].as_mv.row > MV_LOW;
         ret = ret && mv[i].as_mv.col < MV_UPP && mv[i].as_mv.col > MV_LOW;
       }
       break;
     }
     case NEARESTMV: {
       mv[0].as_int = nearest_mv[0].as_int;
       if (is_compound) mv[1].as_int = nearest_mv[1].as_int;
       break;
     }
     case NEARMV: {
       mv[0].as_int = near_mv[0].as_int;
       if (is_compound) mv[1].as_int = near_mv[1].as_int;
       break;
     }
     case ZEROMV: {
       mv[0].as_int = 0;
       if (is_compound) mv[1].as_int = 0;
       break;
     }
     default: {
       return 0;
     }
   }
   return ret;
 }
 static int read_is_inter_block(VP9_COMMON *const cm, MACROBLOCKD *const xd,
                                int segment_id, vp9_reader *r) {
   if (vp9_segfeature_active(&cm->seg, segment_id, SEG_LVL_REF_FRAME)) {
     return vp9_get_segdata(&cm->seg, segment_id, SEG_LVL_REF_FRAME) !=
            INTRA_FRAME;
   } else {
     const int ctx = vp9_get_pred_context_intra_inter(xd);
     const int is_inter = vp9_read(r, vp9_get_pred_prob_intra_inter(cm, xd));
     if (!cm->frame_parallel_decoding_mode)
       ++cm->counts.intra_inter[ctx][is_inter];
     return is_inter;
   }
 }
 static void read_inter_block_mode_info(VP9_COMMON *const cm,
                                        MACROBLOCKD *const xd,
                                        const TileInfo *const tile,
                                        MODE_INFO *const mi,
                                        int mi_row, int mi_col, vp9_reader *r) {
   MB_MODE_INFO *const mbmi = &mi->mbmi;
   const BLOCK_SIZE bsize = mbmi->sb_type;
   const int allow_hp = cm->allow_high_precision_mv;
   int_mv nearest[2], nearmv[2], best[2];
   uint8_t inter_mode_ctx;
   MV_REFERENCE_FRAME ref0;
   int is_compound;
   mbmi->uv_mode = DC_PRED;
   read_ref_frames(cm, xd, r, mbmi->segment_id, mbmi->ref_frame);
   ref0 = mbmi->ref_frame[0];
   is_compound = has_second_ref(mbmi);
   vp9_find_mv_refs(cm, xd, tile, mi, xd->last_mi, ref0, mbmi->ref_mvs[ref0],
                    mi_row, mi_col);
   inter_mode_ctx = mbmi->mode_context[ref0];
   if (vp9_segfeature_active(&cm->seg, mbmi->segment_id, SEG_LVL_SKIP)) {
     mbmi->mode = ZEROMV;
     if (bsize < BLOCK_8X8) {
         vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
                            "Invalid usage of segement feature on small blocks");
         return;
     }
   } else {
     if (bsize >= BLOCK_8X8)
       mbmi->mode = read_inter_mode(cm, r, inter_mode_ctx);
   }
   // nearest, nearby
   if (bsize < BLOCK_8X8 || mbmi->mode != ZEROMV) {
     vp9_find_best_ref_mvs(xd, allow_hp,
                           mbmi->ref_mvs[ref0], &nearest[0], &nearmv[0]);
     best[0].as_int = nearest[0].as_int;
   }
   if (is_compound) {
     const MV_REFERENCE_FRAME ref1 = mbmi->ref_frame[1];
     vp9_find_mv_refs(cm, xd, tile, mi, xd->last_mi,
                      ref1, mbmi->ref_mvs[ref1], mi_row, mi_col);
     if (bsize < BLOCK_8X8 || mbmi->mode != ZEROMV) {
       vp9_find_best_ref_mvs(xd, allow_hp,
                             mbmi->ref_mvs[ref1], &nearest[1], &nearmv[1]);
       best[1].as_int = nearest[1].as_int;
     }
   }
   mbmi->interp_filter = (cm->mcomp_filter_type == SWITCHABLE)
                       ? read_switchable_filter_type(cm, xd, r)
                       : cm->mcomp_filter_type;
   if (bsize < BLOCK_8X8) {
     const int num_4x4_w = num_4x4_blocks_wide_lookup[bsize];  // 1 or 2
     const int num_4x4_h = num_4x4_blocks_high_lookup[bsize];  // 1 or 2
     int idx, idy;
     int b_mode;
     for (idy = 0; idy < 2; idy += num_4x4_h) {
       for (idx = 0; idx < 2; idx += num_4x4_w) {
         int_mv block[2];
         const int j = idy * 2 + idx;
         b_mode = read_inter_mode(cm, r, inter_mode_ctx);
         if (b_mode == NEARESTMV || b_mode == NEARMV) {
           vp9_append_sub8x8_mvs_for_idx(cm, xd, tile, &nearest[0],
                                         &nearmv[0], j, 0,
                                         mi_row, mi_col);
           if (is_compound)
             vp9_append_sub8x8_mvs_for_idx(cm, xd, tile, &nearest[1],
                                           &nearmv[1], j, 1,
                                           mi_row, mi_col);
         }
         if (!assign_mv(cm, b_mode, block, best, nearest, nearmv,
                        is_compound, allow_hp, r)) {
           xd->corrupted |= 1;
           break;
         };
         mi->bmi[j].as_mv[0].as_int = block[0].as_int;
         if (is_compound)
           mi->bmi[j].as_mv[1].as_int = block[1].as_int;
         if (num_4x4_h == 2)
           mi->bmi[j + 2] = mi->bmi[j];
         if (num_4x4_w == 2)
           mi->bmi[j + 1] = mi->bmi[j];
       }
     }
     mi->mbmi.mode = b_mode;
     mbmi->mv[0].as_int = mi->bmi[3].as_mv[0].as_int;
     mbmi->mv[1].as_int = mi->bmi[3].as_mv[1].as_int;
   } else {
     xd->corrupted |= !assign_mv(cm, mbmi->mode, mbmi->mv,
                                 best, nearest, nearmv,
                                 is_compound, allow_hp, r);
   }
 }
 static void read_inter_frame_mode_info(VP9_COMMON *const cm,
                                        MACROBLOCKD *const xd,
                                        const TileInfo *const tile,
                                        MODE_INFO *const mi,
                                        int mi_row, int mi_col, vp9_reader *r) {
   MB_MODE_INFO *const mbmi = &mi->mbmi;
   int inter_block;
   mbmi->mv[0].as_int = 0;
   mbmi->mv[1].as_int = 0;
   mbmi->segment_id = read_inter_segment_id(cm, xd, mi_row, mi_col, r);
   mbmi->skip_coeff = read_skip_coeff(cm, xd, mbmi->segment_id, r);
   inter_block = read_is_inter_block(cm, xd, mbmi->segment_id, r);
   mbmi->tx_size = read_tx_size(cm, xd, cm->tx_mode, mbmi->sb_type,
                                !mbmi->skip_coeff || !inter_block, r);
   if (inter_block)
     read_inter_block_mode_info(cm, xd, tile, mi, mi_row, mi_col, r);
   else
     read_intra_block_mode_info(cm, mi, r);
 }
 void vp9_read_mode_info(VP9_COMMON *cm, MACROBLOCKD *xd,
                         const TileInfo *const tile,
                         int mi_row, int mi_col, vp9_reader *r) {
   MODE_INFO *const mi = xd->mi_8x8[0];
   const BLOCK_SIZE bsize = mi->mbmi.sb_type;
   const int bw = num_8x8_blocks_wide_lookup[bsize];
   const int bh = num_8x8_blocks_high_lookup[bsize];
   const int y_mis = MIN(bh, cm->mi_rows - mi_row);
   const int x_mis = MIN(bw, cm->mi_cols - mi_col);
   int x, y, z;
   if (frame_is_intra_only(cm))
     read_intra_frame_mode_info(cm, xd, mi, mi_row, mi_col, r);
   else
     read_inter_frame_mode_info(cm, xd, tile, mi, mi_row, mi_col, r);
   for (y = 0, z = 0; y < y_mis; y++, z += cm->mode_info_stride) {
     for (x = !y; x < x_mis; x++) {
       xd->mi_8x8[z + x] = mi;
     }
   }
 }

The Tor Browser / annotate

media/libvpx/vp9/decoder/vp9_decodemv.c@ac0c01689b40 (annotated)

media/libvpx/vp9/decoder/vp9_decodemv.c