vp8/decoder/decodemv.c

   1 /*
   2  *  Copyright (c) 2010 The VP8 project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license and patent
   5  *  grant that can be found in the LICENSE file in the root of the source
   6  *  tree. All contributing project authors may be found in the AUTHORS
   7  *  file in the root of the source tree.
   8  */
   9
  10
  11 #include "treereader.h"
  12 #include "entropymv.h"
  13 #include "entropymode.h"
  14 #include "onyxd_int.h"
  15 #include "findnearmv.h"
  16 #include "demode.h"
  17 #if CONFIG_DEBUG
  18 #include <assert.h>
  19 #endif
  20
  21 static int read_mvcomponent(vp8_reader *r, const MV_CONTEXT *mvc)
  22 {
  23     const vp8_prob *const p = (const vp8_prob *) mvc;
  24     int x = 0;
  25
  26     if (vp8_read(r, p [mvpis_short]))  /* Large */
  27     {
  28         int i = 0;
  29
  30         do
  31         {
  32             x += vp8_read(r, p [MVPbits + i]) << i;
  33         }
  34         while (++i < 3);
  35
  36         i = mvlong_width - 1;  /* Skip bit 3, which is sometimes implicit */
  37
  38         do
  39         {
  40             x += vp8_read(r, p [MVPbits + i]) << i;
  41         }
  42         while (--i > 3);
  43
  44         if (!(x & 0xFFF0)  ||  vp8_read(r, p [MVPbits + 3]))
  45             x += 8;
  46     }
  47     else   /* small */
  48         x = vp8_treed_read(r, vp8_small_mvtree, p + MVPshort);
  49
  50     if (x  &&  vp8_read(r, p [MVPsign]))
  51         x = -x;
  52
  53     return x;
  54 }
  55
  56 static void read_mv(vp8_reader *r, MV *mv, const MV_CONTEXT *mvc)
  57 {
  58     mv->row = (short)(read_mvcomponent(r,   mvc) << 1);
  59     mv->col = (short)(read_mvcomponent(r, ++mvc) << 1);
  60 }
  61
  62
  63 static void read_mvcontexts(vp8_reader *bc, MV_CONTEXT *mvc)
  64 {
  65     int i = 0;
  66
  67     do
  68     {
  69         const vp8_prob *up = vp8_mv_update_probs[i].prob;
  70         vp8_prob *p = (vp8_prob *)(mvc + i);
  71         vp8_prob *const pstop = p + MVPcount;
  72
  73         do
  74         {
  75             if (vp8_read(bc, *up++))
  76             {
  77                 const vp8_prob x = (vp8_prob)vp8_read_literal(bc, 7);
  78
  79                 *p = x ? x << 1 : 1;
  80             }
  81         }
  82         while (++p < pstop);
  83     }
  84     while (++i < 2);
  85 }
  86
  87
  88 static MB_PREDICTION_MODE read_mv_ref(vp8_reader *bc, const vp8_prob *p)
  89 {
  90     const int i = vp8_treed_read(bc, vp8_mv_ref_tree, p);
  91
  92     return (MB_PREDICTION_MODE)i;
  93 }
  94
  95 static MB_PREDICTION_MODE sub_mv_ref(vp8_reader *bc, const vp8_prob *p)
  96 {
  97     const int i = vp8_treed_read(bc, vp8_sub_mv_ref_tree, p);
  98
  99     return (MB_PREDICTION_MODE)i;
 100 }
 101 unsigned int vp8_mv_cont_count[5][4] =
 102 {
 103     { 0, 0, 0, 0 },
 104     { 0, 0, 0, 0 },
 105     { 0, 0, 0, 0 },
 106     { 0, 0, 0, 0 },
 107     { 0, 0, 0, 0 }
 108 };
 109
 110 void vp8_decode_mode_mvs(VP8D_COMP *pbi)
 111 {
 112     const MV Zero = { 0, 0};
 113
 114     VP8_COMMON *const pc = & pbi->common;
 115     vp8_reader *const bc = & pbi->bc;
 116
 117     MODE_INFO *mi = pc->mi, *ms;
 118     const int mis = pc->mode_info_stride;
 119
 120     MV_CONTEXT *const mvc = pc->fc.mvc;
 121
 122     int mb_row = -1;
 123
 124     vp8_prob prob_intra;
 125     vp8_prob prob_last;
 126     vp8_prob prob_gf;
 127     vp8_prob prob_skip_false = 0;
 128
 129     if (pc->mb_no_coeff_skip)
 130         prob_skip_false = (vp8_prob)vp8_read_literal(bc, 8);
 131
 132     prob_intra = (vp8_prob)vp8_read_literal(bc, 8);
 133     prob_last  = (vp8_prob)vp8_read_literal(bc, 8);
 134     prob_gf    = (vp8_prob)vp8_read_literal(bc, 8);
 135
 136     ms = pc->mi - 1;
 137
 138     if (vp8_read_bit(bc))
 139     {
 140         int i = 0;
 141
 142         do
 143         {
 144             pc->fc.ymode_prob[i] = (vp8_prob) vp8_read_literal(bc, 8);
 145         }
 146         while (++i < 4);
 147     }
 148
 149     if (vp8_read_bit(bc))
 150     {
 151         int i = 0;
 152
 153         do
 154         {
 155             pc->fc.uv_mode_prob[i] = (vp8_prob) vp8_read_literal(bc, 8);
 156         }
 157         while (++i < 3);
 158     }
 159
 160     read_mvcontexts(bc, mvc);
 161
 162     while (++mb_row < pc->mb_rows)
 163     {
 164         int mb_col = -1;
 165
 166         while (++mb_col < pc->mb_cols)
 167         {
 168             MB_MODE_INFO *const mbmi = & mi->mbmi;
 169             MV *const mv = & mbmi->mv.as_mv;
 170             VP8_COMMON *const pc = &pbi->common;
 171             MACROBLOCKD *xd = &pbi->mb;
 172
 173             vp8dx_bool_decoder_fill(bc);
 174
 175             // Distance of Mb to the various image edges.
 176             // These specified to 8th pel as they are always compared to MV values that are in 1/8th pel units
 177             xd->mb_to_left_edge = -((mb_col * 16) << 3);
 178             xd->mb_to_right_edge = ((pc->mb_cols - 1 - mb_col) * 16) << 3;
 179             xd->mb_to_top_edge = -((mb_row * 16)) << 3;
 180             xd->mb_to_bottom_edge = ((pc->mb_rows - 1 - mb_row) * 16) << 3;
 181
 182             // If required read in new segmentation data for this MB
 183             if (pbi->mb.update_mb_segmentation_map)
 184                 vp8_read_mb_features(bc, mbmi, &pbi->mb);
 185
 186             // Read the macroblock coeff skip flag if this feature is in use, else default to 0
 187             if (pc->mb_no_coeff_skip)
 188                 mbmi->mb_skip_coeff = vp8_read(bc, prob_skip_false);
 189             else
 190                 mbmi->mb_skip_coeff = 0;
 191
 192             mbmi->uv_mode = DC_PRED;
 193
 194             if ((mbmi->ref_frame = (MV_REFERENCE_FRAME) vp8_read(bc, prob_intra)))    /* inter MB */
 195             {
 196                 int rct[4];
 197                 vp8_prob mv_ref_p [VP8_MVREFS-1];
 198                 MV nearest, nearby, best_mv;
 199
 200                 if (vp8_read(bc, prob_last))
 201                 {
 202                     mbmi->ref_frame = (MV_REFERENCE_FRAME)((int)mbmi->ref_frame + (int)(1 + vp8_read(bc, prob_gf)));
 203                 }
 204
 205                 vp8_find_near_mvs(xd, mi, &nearest, &nearby, &best_mv, rct, mbmi->ref_frame, pbi->common.ref_frame_sign_bias);
 206
 207                 vp8_mv_ref_probs(mv_ref_p, rct);
 208
 209                 switch (mbmi->mode = read_mv_ref(bc, mv_ref_p))
 210                 {
 211                 case SPLITMV:
 212                 {
 213                     const int s = mbmi->partitioning = vp8_treed_read(
 214                                                            bc, vp8_mbsplit_tree, vp8_mbsplit_probs
 215                                                        );
 216                     const int num_p = vp8_mbsplit_count [s];
 217                     const int *const  L = vp8_mbsplits [s];
 218                     int j = 0;
 219
 220                     do  /* for each subset j */
 221                     {
 222                         B_MODE_INFO *const bmi = mbmi->partition_bmi + j;
 223                         MV *const mv = & bmi->mv.as_mv;
 224
 225                         int k = -1;  /* first block in subset j */
 226                         int mv_contz;
 227
 228                         while (j != L[++k])
 229                             if (k >= 16)
 230 #if CONFIG_DEBUG
 231                                 assert(0);
 232
 233 #else
 234                                 ;
 235 #endif
 236
 237                         mv_contz = vp8_mv_cont(&(vp8_left_bmi(mi, k)->mv.as_mv), &(vp8_above_bmi(mi, k, mis)->mv.as_mv));
 238
 239                         switch (bmi->mode = (B_PREDICTION_MODE) sub_mv_ref(bc, vp8_sub_mv_ref_prob2 [mv_contz])) //pc->fc.sub_mv_ref_prob))
 240                         {
 241                         case NEW4X4:
 242                             read_mv(bc, mv, (const MV_CONTEXT *) mvc);
 243                             mv->row += best_mv.row;
 244                             mv->col += best_mv.col;
 245 #ifdef VPX_MODE_COUNT
 246                             vp8_mv_cont_count[mv_contz][3]++;
 247 #endif
 248                             break;
 249                         case LEFT4X4:
 250                             *mv = vp8_left_bmi(mi, k)->mv.as_mv;
 251 #ifdef VPX_MODE_COUNT
 252                             vp8_mv_cont_count[mv_contz][0]++;
 253 #endif
 254                             break;
 255                         case ABOVE4X4:
 256                             *mv = vp8_above_bmi(mi, k, mis)->mv.as_mv;
 257 #ifdef VPX_MODE_COUNT
 258                             vp8_mv_cont_count[mv_contz][1]++;
 259 #endif
 260                             break;
 261                         case ZERO4X4:
 262                             *mv = Zero;
 263 #ifdef VPX_MODE_COUNT
 264                             vp8_mv_cont_count[mv_contz][2]++;
 265 #endif
 266                             break;
 267                         default:
 268                             break;
 269                         }
 270
 271                         /* Fill (uniform) modes, mvs of jth subset.
 272                            Must do it here because ensuing subsets can
 273                            refer back to us via "left" or "above". */
 274                         do
 275                             if (j == L[k])
 276                                 mi->bmi[k] = *bmi;
 277
 278                         while (++k < 16);
 279                     }
 280                     while (++j < num_p);
 281                 }
 282
 283                 *mv = mi->bmi[15].mv.as_mv;
 284
 285                 break;  /* done with SPLITMV */
 286
 287                 case NEARMV:
 288                     *mv = nearby;
 289
 290                     // Clip "next_nearest" so that it does not extend to far out of image
 291                     if (mv->col < (xd->mb_to_left_edge - LEFT_TOP_MARGIN))
 292                         mv->col = xd->mb_to_left_edge - LEFT_TOP_MARGIN;
 293                     else if (mv->col > xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN)
 294                         mv->col = xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN;
 295
 296                     if (mv->row < (xd->mb_to_top_edge - LEFT_TOP_MARGIN))
 297                         mv->row = xd->mb_to_top_edge - LEFT_TOP_MARGIN;
 298                     else if (mv->row > xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN)
 299                         mv->row = xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN;
 300
 301                     goto propagate_mv;
 302
 303                 case NEARESTMV:
 304                     *mv = nearest;
 305
 306                     // Clip "next_nearest" so that it does not extend to far out of image
 307                     if (mv->col < (xd->mb_to_left_edge - LEFT_TOP_MARGIN))
 308                         mv->col = xd->mb_to_left_edge - LEFT_TOP_MARGIN;
 309                     else if (mv->col > xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN)
 310                         mv->col = xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN;
 311
 312                     if (mv->row < (xd->mb_to_top_edge - LEFT_TOP_MARGIN))
 313                         mv->row = xd->mb_to_top_edge - LEFT_TOP_MARGIN;
 314                     else if (mv->row > xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN)
 315                         mv->row = xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN;
 316
 317                     goto propagate_mv;
 318
 319                 case ZEROMV:
 320                     *mv = Zero;
 321                     goto propagate_mv;
 322
 323                 case NEWMV:
 324                     read_mv(bc, mv, (const MV_CONTEXT *) mvc);
 325                     mv->row += best_mv.row;
 326                     mv->col += best_mv.col;
 327                     /* Encoder should not produce invalid motion vectors, but since
 328                      * arbitrary length MVs can be parsed from the bitstream, we
 329                      * need to clamp them here in case we're reading bad data to
 330                      * avoid a crash.
 331                      */
 332 #if CONFIG_DEBUG
 333                     assert(mv->col >= (xd->mb_to_left_edge - LEFT_TOP_MARGIN));
 334                     assert(mv->col <= (xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN));
 335                     assert(mv->row >= (xd->mb_to_top_edge - LEFT_TOP_MARGIN));
 336                     assert(mv->row <= (xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN));
 337 #endif
 338
 339                     if (mv->col < (xd->mb_to_left_edge - LEFT_TOP_MARGIN))
 340                         mv->col = xd->mb_to_left_edge - LEFT_TOP_MARGIN;
 341                     else if (mv->col > xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN)
 342                         mv->col = xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN;
 343
 344                     if (mv->row < (xd->mb_to_top_edge - LEFT_TOP_MARGIN))
 345                         mv->row = xd->mb_to_top_edge - LEFT_TOP_MARGIN;
 346                     else if (mv->row > xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN)
 347                         mv->row = xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN;
 348
 349                 propagate_mv:  /* same MV throughout */
 350                     {
 351                         //int i=0;
 352                         //do
 353                         //{
 354                         //  mi->bmi[i].mv.as_mv = *mv;
 355                         //}
 356                         //while( ++i < 16);
 357
 358                         mi->bmi[0].mv.as_mv = *mv;
 359                         mi->bmi[1].mv.as_mv = *mv;
 360                         mi->bmi[2].mv.as_mv = *mv;
 361                         mi->bmi[3].mv.as_mv = *mv;
 362                         mi->bmi[4].mv.as_mv = *mv;
 363                         mi->bmi[5].mv.as_mv = *mv;
 364                         mi->bmi[6].mv.as_mv = *mv;
 365                         mi->bmi[7].mv.as_mv = *mv;
 366                         mi->bmi[8].mv.as_mv = *mv;
 367                         mi->bmi[9].mv.as_mv = *mv;
 368                         mi->bmi[10].mv.as_mv = *mv;
 369                         mi->bmi[11].mv.as_mv = *mv;
 370                         mi->bmi[12].mv.as_mv = *mv;
 371                         mi->bmi[13].mv.as_mv = *mv;
 372                         mi->bmi[14].mv.as_mv = *mv;
 373                         mi->bmi[15].mv.as_mv = *mv;
 374                     }
 375
 376                     break;
 377
 378                 default:;
 379 #if CONFIG_DEBUG
 380                     assert(0);
 381 #endif
 382                 }
 383
 384             }
 385             else
 386             {
 387                 /* MB is intra coded */
 388
 389                 int j = 0;
 390
 391                 do
 392                 {
 393                     mi->bmi[j].mv.as_mv = Zero;
 394                 }
 395                 while (++j < 16);
 396
 397                 *mv = Zero;
 398
 399                 if ((mbmi->mode = (MB_PREDICTION_MODE) vp8_read_ymode(bc, pc->fc.ymode_prob)) == B_PRED)
 400                 {
 401                     int j = 0;
 402
 403                     do
 404                     {
 405                         mi->bmi[j].mode = (B_PREDICTION_MODE)vp8_read_bmode(bc, pc->fc.bmode_prob);
 406                     }
 407                     while (++j < 16);
 408                 }
 409
 410                 mbmi->uv_mode = (MB_PREDICTION_MODE)vp8_read_uv_mode(bc, pc->fc.uv_mode_prob);
 411             }
 412
 413             mi++;       // next macroblock
 414         }
 415
 416         mi++;           // skip left predictor each row
 417     }
 418 }