The Tor Browser: media/libvpx/vp9/common/vp9_pred

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.

     2 /*

     3  *  Copyright (c) 2012 The WebM project authors. All Rights Reserved.

     4  *

     5  *  Use of this source code is governed by a BSD-style license

     6  *  that can be found in the LICENSE file in the root of the source

     7  *  tree. An additional intellectual property rights grant can be found

     8  *  in the file PATENTS.  All contributing project authors may

     9  *  be found in the AUTHORS file in the root of the source tree.

    10  */

    12 #include <limits.h>

    14 #include "vp9/common/vp9_common.h"

    15 #include "vp9/common/vp9_pred_common.h"

    16 #include "vp9/common/vp9_seg_common.h"

    17 #include "vp9/common/vp9_treecoder.h"

    19 static INLINE const MB_MODE_INFO *get_above_mbmi(const MODE_INFO *const above) {

    20   return (above != NULL) ? &above->mbmi : NULL;

    21 }

    23 static INLINE const MB_MODE_INFO *get_left_mbmi(const MODE_INFO *const left) {

    24   return (left != NULL) ? &left->mbmi : NULL;

    25 }

    27 // Returns a context number for the given MB prediction signal

    28 unsigned char vp9_get_pred_context_switchable_interp(const MACROBLOCKD *xd) {

    29   const MODE_INFO *const above_mi = get_above_mi(xd);

    30   const MODE_INFO *const left_mi = get_left_mi(xd);

    31   const int above_in_image = above_mi != NULL;

    32   const int left_in_image = left_mi != NULL;

    33   // Note:

    34   // The mode info data structure has a one element border above and to the

    35   // left of the entries correpsonding to real macroblocks.

    36   // The prediction flags in these dummy entries are initialised to 0.

    37   // left

    38   const int left_mv_pred = left_in_image ? is_inter_block(&left_mi->mbmi)

    39                                          : 0;

    40   const int left_interp = left_in_image && left_mv_pred

    41                               ? left_mi->mbmi.interp_filter

    42                               : SWITCHABLE_FILTERS;

    44   // above

    45   const int above_mv_pred = above_in_image ? is_inter_block(&above_mi->mbmi)

    46                                            : 0;

    47   const int above_interp = above_in_image && above_mv_pred

    48                                ? above_mi->mbmi.interp_filter

    49                                : SWITCHABLE_FILTERS;

    51   if (left_interp == above_interp)

    52     return left_interp;

    53   else if (left_interp == SWITCHABLE_FILTERS &&

    54            above_interp != SWITCHABLE_FILTERS)

    55     return above_interp;

    56   else if (left_interp != SWITCHABLE_FILTERS &&

    57            above_interp == SWITCHABLE_FILTERS)

    58     return left_interp;

    59   else

    60     return SWITCHABLE_FILTERS;

    61 }

    62 // Returns a context number for the given MB prediction signal

    63 unsigned char vp9_get_pred_context_intra_inter(const MACROBLOCKD *xd) {

    64   const MODE_INFO *const above_mi = get_above_mi(xd);

    65   const MODE_INFO *const left_mi = get_left_mi(xd);

    66   const MB_MODE_INFO *const above_mbmi = get_above_mbmi(above_mi);

    67   const MB_MODE_INFO *const left_mbmi = get_left_mbmi(left_mi);

    68   const int above_in_image = above_mi != NULL;

    69   const int left_in_image = left_mi != NULL;

    70   const int above_intra = above_in_image ? !is_inter_block(above_mbmi) : 1;

    71   const int left_intra = left_in_image ? !is_inter_block(left_mbmi) : 1;

    73   // The mode info data structure has a one element border above and to the

    74   // left of the entries corresponding to real macroblocks.

    75   // The prediction flags in these dummy entries are initialized to 0.

    76   // 0 - inter/inter, inter/--, --/inter, --/--

    77   // 1 - intra/inter, inter/intra

    78   // 2 - intra/--, --/intra

    79   // 3 - intra/intra

    80   if (above_in_image && left_in_image)  // both edges available

    81     return left_intra && above_intra ? 3

    82                                      : left_intra || above_intra;

    83   else if (above_in_image || left_in_image)  // one edge available

    84     return 2 * (above_in_image ? above_intra : left_intra);

    85   else

    86     return 0;

    87 }

    88 // Returns a context number for the given MB prediction signal

    89 unsigned char vp9_get_pred_context_comp_inter_inter(const VP9_COMMON *cm,

    90                                                     const MACROBLOCKD *xd) {

    91   int pred_context;

    92   const MODE_INFO *const above_mi = get_above_mi(xd);

    93   const MODE_INFO *const left_mi = get_left_mi(xd);

    94   const MB_MODE_INFO *const above_mbmi = get_above_mbmi(above_mi);

    95   const MB_MODE_INFO *const left_mbmi = get_left_mbmi(left_mi);

    96   const int above_in_image = above_mi != NULL;

    97   const int left_in_image = left_mi != NULL;

    98   // Note:

    99   // The mode info data structure has a one element border above and to the

   100   // left of the entries correpsonding to real macroblocks.

   101   // The prediction flags in these dummy entries are initialised to 0.

   102   if (above_in_image && left_in_image) {  // both edges available

   103     if (!has_second_ref(above_mbmi) && !has_second_ref(left_mbmi))

   104       // neither edge uses comp pred (0/1)

   105       pred_context = (above_mbmi->ref_frame[0] == cm->comp_fixed_ref) ^

   106                      (left_mbmi->ref_frame[0] == cm->comp_fixed_ref);

   107     else if (!has_second_ref(above_mbmi))

   108       // one of two edges uses comp pred (2/3)

   109       pred_context = 2 + (above_mbmi->ref_frame[0] == cm->comp_fixed_ref ||

   110                           !is_inter_block(above_mbmi));

   111     else if (!has_second_ref(left_mbmi))

   112       // one of two edges uses comp pred (2/3)

   113       pred_context = 2 + (left_mbmi->ref_frame[0] == cm->comp_fixed_ref ||

   114                           !is_inter_block(left_mbmi));

   115     else  // both edges use comp pred (4)

   116       pred_context = 4;

   117   } else if (above_in_image || left_in_image) {  // one edge available

   118     const MB_MODE_INFO *edge_mbmi = above_in_image ? above_mbmi : left_mbmi;

   120     if (!has_second_ref(edge_mbmi))

   121       // edge does not use comp pred (0/1)

   122       pred_context = edge_mbmi->ref_frame[0] == cm->comp_fixed_ref;

   123     else

   124       // edge uses comp pred (3)

   125       pred_context = 3;

   126   } else {  // no edges available (1)

   127     pred_context = 1;

   128   }

   129   assert(pred_context >= 0 && pred_context < COMP_INTER_CONTEXTS);

   130   return pred_context;

   131 }

   133 // Returns a context number for the given MB prediction signal

   134 unsigned char vp9_get_pred_context_comp_ref_p(const VP9_COMMON *cm,

   135                                               const MACROBLOCKD *xd) {

   136   int pred_context;

   137   const MODE_INFO *const above_mi = get_above_mi(xd);

   138   const MODE_INFO *const left_mi = get_left_mi(xd);

   139   const MB_MODE_INFO *const above_mbmi = get_above_mbmi(above_mi);

   140   const MB_MODE_INFO *const left_mbmi = get_left_mbmi(left_mi);

   141   const int above_in_image = above_mi != NULL;

   142   const int left_in_image = left_mi != NULL;

   143   const int above_intra = above_in_image ? !is_inter_block(above_mbmi) : 1;

   144   const int left_intra = left_in_image ? !is_inter_block(left_mbmi) : 1;

   145   // Note:

   146   // The mode info data structure has a one element border above and to the

   147   // left of the entries correpsonding to real macroblocks.

   148   // The prediction flags in these dummy entries are initialised to 0.

   149   const int fix_ref_idx = cm->ref_frame_sign_bias[cm->comp_fixed_ref];

   150   const int var_ref_idx = !fix_ref_idx;

   152   if (above_in_image && left_in_image) {  // both edges available

   153     if (above_intra && left_intra) {  // intra/intra (2)

   154       pred_context = 2;

   155     } else if (above_intra || left_intra) {  // intra/inter

   156       const MB_MODE_INFO *edge_mbmi = above_intra ? left_mbmi : above_mbmi;

   158       if (!has_second_ref(edge_mbmi))  // single pred (1/3)

   159         pred_context = 1 + 2 * (edge_mbmi->ref_frame[0] != cm->comp_var_ref[1]);

   160       else  // comp pred (1/3)

   161         pred_context = 1 + 2 * (edge_mbmi->ref_frame[var_ref_idx]

   162                                     != cm->comp_var_ref[1]);

   163     } else {  // inter/inter

   164       const int l_sg = !has_second_ref(left_mbmi);

   165       const int a_sg = !has_second_ref(above_mbmi);

   166       MV_REFERENCE_FRAME vrfa = a_sg ? above_mbmi->ref_frame[0]

   167                                      : above_mbmi->ref_frame[var_ref_idx];

   168       MV_REFERENCE_FRAME vrfl = l_sg ? left_mbmi->ref_frame[0]

   169                                      : left_mbmi->ref_frame[var_ref_idx];

   171       if (vrfa == vrfl && cm->comp_var_ref[1] == vrfa) {

   172         pred_context = 0;

   173       } else if (l_sg && a_sg) {  // single/single

   174         if ((vrfa == cm->comp_fixed_ref && vrfl == cm->comp_var_ref[0]) ||

   175             (vrfl == cm->comp_fixed_ref && vrfa == cm->comp_var_ref[0]))

   176           pred_context = 4;

   177         else if (vrfa == vrfl)

   178           pred_context = 3;

   179         else

   180           pred_context = 1;

   181       } else if (l_sg || a_sg) {  // single/comp

   182         MV_REFERENCE_FRAME vrfc = l_sg ? vrfa : vrfl;

   183         MV_REFERENCE_FRAME rfs = a_sg ? vrfa : vrfl;

   184         if (vrfc == cm->comp_var_ref[1] && rfs != cm->comp_var_ref[1])

   185           pred_context = 1;

   186         else if (rfs == cm->comp_var_ref[1] && vrfc != cm->comp_var_ref[1])

   187           pred_context = 2;

   188         else

   189           pred_context = 4;

   190       } else if (vrfa == vrfl) {  // comp/comp

   191         pred_context = 4;

   192       } else {

   193         pred_context = 2;

   194       }

   195     }

   196   } else if (above_in_image || left_in_image) {  // one edge available

   197     const MB_MODE_INFO *edge_mbmi = above_in_image ? above_mbmi : left_mbmi;

   199     if (!is_inter_block(edge_mbmi)) {

   200       pred_context = 2;

   201     } else {

   202       if (has_second_ref(edge_mbmi))

   203         pred_context = 4 * (edge_mbmi->ref_frame[var_ref_idx]

   204                               != cm->comp_var_ref[1]);

   205       else

   206         pred_context = 3 * (edge_mbmi->ref_frame[0] != cm->comp_var_ref[1]);

   207     }

   208   } else {  // no edges available (2)

   209     pred_context = 2;

   210   }

   211   assert(pred_context >= 0 && pred_context < REF_CONTEXTS);

   213   return pred_context;

   214 }

   215 unsigned char vp9_get_pred_context_single_ref_p1(const MACROBLOCKD *xd) {

   216   int pred_context;

   217   const MODE_INFO *const above_mi = get_above_mi(xd);

   218   const MODE_INFO *const left_mi = get_left_mi(xd);

   219   const MB_MODE_INFO *const above_mbmi = get_above_mbmi(above_mi);

   220   const MB_MODE_INFO *const left_mbmi = get_left_mbmi(left_mi);

   221   const int above_in_image = above_mi != NULL;

   222   const int left_in_image = left_mi != NULL;

   223   const int above_intra = above_in_image ? !is_inter_block(above_mbmi) : 1;

   224   const int left_intra = left_in_image ? !is_inter_block(left_mbmi) : 1;

   225   // Note:

   226   // The mode info data structure has a one element border above and to the

   227   // left of the entries correpsonding to real macroblocks.

   228   // The prediction flags in these dummy entries are initialised to 0.

   229   if (above_in_image && left_in_image) {  // both edges available

   230     if (above_intra && left_intra) {  // intra/intra

   231       pred_context = 2;

   232     } else if (above_intra || left_intra) {  // intra/inter or inter/intra

   233       const MB_MODE_INFO *edge_mbmi = above_intra ? left_mbmi : above_mbmi;

   234       if (!has_second_ref(edge_mbmi))

   235         pred_context = 4 * (edge_mbmi->ref_frame[0] == LAST_FRAME);

   236       else

   237         pred_context = 1 + (edge_mbmi->ref_frame[0] == LAST_FRAME ||

   238                             edge_mbmi->ref_frame[1] == LAST_FRAME);

   239     } else {  // inter/inter

   240       if (!has_second_ref(above_mbmi) && !has_second_ref(left_mbmi)) {

   241         pred_context = 2 * (above_mbmi->ref_frame[0] == LAST_FRAME) +

   242                        2 * (left_mbmi->ref_frame[0] == LAST_FRAME);

   243       } else if (has_second_ref(above_mbmi) && has_second_ref(left_mbmi)) {

   244         pred_context = 1 + (above_mbmi->ref_frame[0] == LAST_FRAME ||

   245                             above_mbmi->ref_frame[1] == LAST_FRAME ||

   246                             left_mbmi->ref_frame[0] == LAST_FRAME ||

   247                             left_mbmi->ref_frame[1] == LAST_FRAME);

   248       } else {

   249         const MV_REFERENCE_FRAME rfs = !has_second_ref(above_mbmi) ?

   250                   above_mbmi->ref_frame[0] : left_mbmi->ref_frame[0];

   251         const MV_REFERENCE_FRAME crf1 = has_second_ref(above_mbmi) ?

   252                   above_mbmi->ref_frame[0] : left_mbmi->ref_frame[0];

   253         const MV_REFERENCE_FRAME crf2 = has_second_ref(above_mbmi) ?

   254                   above_mbmi->ref_frame[1] : left_mbmi->ref_frame[1];

   256         if (rfs == LAST_FRAME)

   257           pred_context = 3 + (crf1 == LAST_FRAME || crf2 == LAST_FRAME);

   258         else

   259           pred_context = crf1 == LAST_FRAME || crf2 == LAST_FRAME;

   260       }

   261     }

   262   } else if (above_in_image || left_in_image) {  // one edge available

   263     const MB_MODE_INFO *edge_mbmi = above_in_image ? above_mbmi : left_mbmi;

   264     if (!is_inter_block(edge_mbmi)) {  // intra

   265       pred_context = 2;

   266     } else {  // inter

   267       if (!has_second_ref(edge_mbmi))

   268         pred_context = 4 * (edge_mbmi->ref_frame[0] == LAST_FRAME);

   269       else

   270         pred_context = 1 + (edge_mbmi->ref_frame[0] == LAST_FRAME ||

   271                             edge_mbmi->ref_frame[1] == LAST_FRAME);

   272     }

   273   } else {  // no edges available

   274     pred_context = 2;

   275   }

   277   assert(pred_context >= 0 && pred_context < REF_CONTEXTS);

   278   return pred_context;

   279 }

   281 unsigned char vp9_get_pred_context_single_ref_p2(const MACROBLOCKD *xd) {

   282   int pred_context;

   283   const MODE_INFO *const above_mi = get_above_mi(xd);

   284   const MODE_INFO *const left_mi = get_left_mi(xd);

   285   const MB_MODE_INFO *const above_mbmi = get_above_mbmi(above_mi);

   286   const MB_MODE_INFO *const left_mbmi = get_left_mbmi(left_mi);

   287   const int above_in_image = above_mi != NULL;

   288   const int left_in_image = left_mi != NULL;

   289   const int above_intra = above_in_image ? !is_inter_block(above_mbmi) : 1;

   290   const int left_intra = left_in_image ? !is_inter_block(left_mbmi) : 1;

   292   // Note:

   293   // The mode info data structure has a one element border above and to the

   294   // left of the entries correpsonding to real macroblocks.

   295   // The prediction flags in these dummy entries are initialised to 0.

   296   if (above_in_image && left_in_image) {  // both edges available

   297     if (above_intra && left_intra) {  // intra/intra

   298       pred_context = 2;

   299     } else if (above_intra || left_intra) {  // intra/inter or inter/intra

   300       const MB_MODE_INFO *edge_mbmi = above_intra ? left_mbmi : above_mbmi;

   301       if (!has_second_ref(edge_mbmi)) {

   302         if (edge_mbmi->ref_frame[0] == LAST_FRAME)

   303           pred_context = 3;

   304         else

   305           pred_context = 4 * (edge_mbmi->ref_frame[0] == GOLDEN_FRAME);

   306       } else {

   307         pred_context = 1 + 2 * (edge_mbmi->ref_frame[0] == GOLDEN_FRAME ||

   308                                 edge_mbmi->ref_frame[1] == GOLDEN_FRAME);

   309       }

   310     } else {  // inter/inter

   311       if (!has_second_ref(above_mbmi) && !has_second_ref(left_mbmi)) {

   312         if (above_mbmi->ref_frame[0] == LAST_FRAME &&

   313             left_mbmi->ref_frame[0] == LAST_FRAME) {

   314           pred_context = 3;

   315         } else if (above_mbmi->ref_frame[0] == LAST_FRAME ||

   316                    left_mbmi->ref_frame[0] == LAST_FRAME) {

   317           const MB_MODE_INFO *edge_mbmi =

   318               above_mbmi->ref_frame[0] == LAST_FRAME ? left_mbmi : above_mbmi;

   320           pred_context = 4 * (edge_mbmi->ref_frame[0] == GOLDEN_FRAME);

   321         } else {

   322           pred_context = 2 * (above_mbmi->ref_frame[0] == GOLDEN_FRAME) +

   323                          2 * (left_mbmi->ref_frame[0] == GOLDEN_FRAME);

   324         }

   325       } else if (has_second_ref(above_mbmi) && has_second_ref(left_mbmi)) {

   326         if (above_mbmi->ref_frame[0] == left_mbmi->ref_frame[0] &&

   327             above_mbmi->ref_frame[1] == left_mbmi->ref_frame[1])

   328           pred_context = 3 * (above_mbmi->ref_frame[0] == GOLDEN_FRAME ||

   329                               above_mbmi->ref_frame[1] == GOLDEN_FRAME ||

   330                               left_mbmi->ref_frame[0] == GOLDEN_FRAME ||

   331                               left_mbmi->ref_frame[1] == GOLDEN_FRAME);

   332         else

   333           pred_context = 2;

   334       } else {

   335         const MV_REFERENCE_FRAME rfs = !has_second_ref(above_mbmi) ?

   336                   above_mbmi->ref_frame[0] : left_mbmi->ref_frame[0];

   337         const MV_REFERENCE_FRAME crf1 = has_second_ref(above_mbmi) ?

   338                   above_mbmi->ref_frame[0] : left_mbmi->ref_frame[0];

   339         const MV_REFERENCE_FRAME crf2 = has_second_ref(above_mbmi) ?

   340                   above_mbmi->ref_frame[1] : left_mbmi->ref_frame[1];

   342         if (rfs == GOLDEN_FRAME)

   343           pred_context = 3 + (crf1 == GOLDEN_FRAME || crf2 == GOLDEN_FRAME);

   344         else if (rfs == ALTREF_FRAME)

   345           pred_context = crf1 == GOLDEN_FRAME || crf2 == GOLDEN_FRAME;

   346         else

   347           pred_context = 1 + 2 * (crf1 == GOLDEN_FRAME || crf2 == GOLDEN_FRAME);

   348       }

   349     }

   350   } else if (above_in_image || left_in_image) {  // one edge available

   351     const MB_MODE_INFO *edge_mbmi = above_in_image ? above_mbmi : left_mbmi;

   353     if (!is_inter_block(edge_mbmi) ||

   354         (edge_mbmi->ref_frame[0] == LAST_FRAME && !has_second_ref(edge_mbmi)))

   355       pred_context = 2;

   356     else if (!has_second_ref(edge_mbmi))

   357       pred_context = 4 * (edge_mbmi->ref_frame[0] == GOLDEN_FRAME);

   358     else

   359       pred_context = 3 * (edge_mbmi->ref_frame[0] == GOLDEN_FRAME ||

   360                           edge_mbmi->ref_frame[1] == GOLDEN_FRAME);

   361   } else {  // no edges available (2)

   362     pred_context = 2;

   363   }

   364   assert(pred_context >= 0 && pred_context < REF_CONTEXTS);

   365   return pred_context;

   366 }

   367 // Returns a context number for the given MB prediction signal

   368 // The mode info data structure has a one element border above and to the

   369 // left of the entries corresponding to real blocks.

   370 // The prediction flags in these dummy entries are initialized to 0.

   371 unsigned char vp9_get_pred_context_tx_size(const MACROBLOCKD *xd) {

   372   const MODE_INFO *const above_mi = get_above_mi(xd);

   373   const MODE_INFO *const left_mi = get_left_mi(xd);

   374   const MB_MODE_INFO *const above_mbmi = get_above_mbmi(above_mi);

   375   const MB_MODE_INFO *const left_mbmi = get_left_mbmi(left_mi);

   376   const int above_in_image = above_mi != NULL;

   377   const int left_in_image = left_mi != NULL;

   378   const int max_tx_size = max_txsize_lookup[xd->mi_8x8[0]->mbmi.sb_type];

   379   int above_context = max_tx_size;

   380   int left_context = max_tx_size;

   382   if (above_in_image)

   383     above_context = above_mbmi->skip_coeff ? max_tx_size

   384                                            : above_mbmi->tx_size;

   386   if (left_in_image)

   387     left_context = left_mbmi->skip_coeff ? max_tx_size

   388                                          : left_mbmi->tx_size;

   390   if (!left_in_image)

   391     left_context = above_context;

   393   if (!above_in_image)

   394     above_context = left_context;

   396   return above_context + left_context > max_tx_size;

   397 }

   399 void vp9_set_pred_flag_seg_id(MACROBLOCKD *xd, uint8_t pred_flag) {

   400   xd->mi_8x8[0]->mbmi.seg_id_predicted = pred_flag;

   401 }

   403 int vp9_get_segment_id(VP9_COMMON *cm, const uint8_t *segment_ids,

   404                        BLOCK_SIZE bsize, int mi_row, int mi_col) {

   405   const int mi_offset = mi_row * cm->mi_cols + mi_col;

   406   const int bw = num_8x8_blocks_wide_lookup[bsize];

   407   const int bh = num_8x8_blocks_high_lookup[bsize];

   408   const int xmis = MIN(cm->mi_cols - mi_col, bw);

   409   const int ymis = MIN(cm->mi_rows - mi_row, bh);

   410   int x, y, segment_id = INT_MAX;

   412   for (y = 0; y < ymis; y++)

   413     for (x = 0; x < xmis; x++)

   414       segment_id = MIN(segment_id,

   415                        segment_ids[mi_offset + y * cm->mi_cols + x]);

   417   assert(segment_id >= 0 && segment_id < MAX_SEGMENTS);

   418   return segment_id;

   419 }

The Tor Browser / file revision

media/libvpx/vp9/common/vp9_pred_common.c@ac0c01689b40

media/libvpx/vp9/common/vp9_pred_common.c