git.sesse.net Git - ffmpeg/blob - libavcodec/h264_cavlc.c

   1 /*
   2  * H.26L/H.264/AVC/JVT/14496-10/... cavlc bitstream decoding
   3  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file libavcodec/h264_cavlc.c
  24  * H.264 / AVC / MPEG4 part10 cavlc bitstream decoding.
  25  * @author Michael Niedermayer <michaelni@gmx.at>
  26  */
  27
  28 #define CABAC 0
  29
  30 #include "internal.h"
  31 #include "avcodec.h"
  32 #include "mpegvideo.h"
  33 #include "h264.h"
  34 #include "h264data.h" // FIXME FIXME FIXME
  35 #include "h264_mvpred.h"
  36 #include "golomb.h"
  37
  38 //#undef NDEBUG
  39 #include <assert.h>
  40
  41 static const uint8_t golomb_to_inter_cbp_gray[16]={
  42  0, 1, 2, 4, 8, 3, 5,10,12,15, 7,11,13,14, 6, 9,
  43 };
  44
  45 static const uint8_t golomb_to_intra4x4_cbp_gray[16]={
  46 15, 0, 7,11,13,14, 3, 5,10,12, 1, 2, 4, 8, 6, 9,
  47 };
  48
  49 static const uint8_t chroma_dc_coeff_token_len[4*5]={
  50  2, 0, 0, 0,
  51  6, 1, 0, 0,
  52  6, 6, 3, 0,
  53  6, 7, 7, 6,
  54  6, 8, 8, 7,
  55 };
  56
  57 static const uint8_t chroma_dc_coeff_token_bits[4*5]={
  58  1, 0, 0, 0,
  59  7, 1, 0, 0,
  60  4, 6, 1, 0,
  61  3, 3, 2, 5,
  62  2, 3, 2, 0,
  63 };
  64
  65 static const uint8_t coeff_token_len[4][4*17]={
  66 {
  67      1, 0, 0, 0,
  68      6, 2, 0, 0,     8, 6, 3, 0,     9, 8, 7, 5,    10, 9, 8, 6,
  69     11,10, 9, 7,    13,11,10, 8,    13,13,11, 9,    13,13,13,10,
  70     14,14,13,11,    14,14,14,13,    15,15,14,14,    15,15,15,14,
  71     16,15,15,15,    16,16,16,15,    16,16,16,16,    16,16,16,16,
  72 },
  73 {
  74      2, 0, 0, 0,
  75      6, 2, 0, 0,     6, 5, 3, 0,     7, 6, 6, 4,     8, 6, 6, 4,
  76      8, 7, 7, 5,     9, 8, 8, 6,    11, 9, 9, 6,    11,11,11, 7,
  77     12,11,11, 9,    12,12,12,11,    12,12,12,11,    13,13,13,12,
  78     13,13,13,13,    13,14,13,13,    14,14,14,13,    14,14,14,14,
  79 },
  80 {
  81      4, 0, 0, 0,
  82      6, 4, 0, 0,     6, 5, 4, 0,     6, 5, 5, 4,     7, 5, 5, 4,
  83      7, 5, 5, 4,     7, 6, 6, 4,     7, 6, 6, 4,     8, 7, 7, 5,
  84      8, 8, 7, 6,     9, 8, 8, 7,     9, 9, 8, 8,     9, 9, 9, 8,
  85     10, 9, 9, 9,    10,10,10,10,    10,10,10,10,    10,10,10,10,
  86 },
  87 {
  88      6, 0, 0, 0,
  89      6, 6, 0, 0,     6, 6, 6, 0,     6, 6, 6, 6,     6, 6, 6, 6,
  90      6, 6, 6, 6,     6, 6, 6, 6,     6, 6, 6, 6,     6, 6, 6, 6,
  91      6, 6, 6, 6,     6, 6, 6, 6,     6, 6, 6, 6,     6, 6, 6, 6,
  92      6, 6, 6, 6,     6, 6, 6, 6,     6, 6, 6, 6,     6, 6, 6, 6,
  93 }
  94 };
  95
  96 static const uint8_t coeff_token_bits[4][4*17]={
  97 {
  98      1, 0, 0, 0,
  99      5, 1, 0, 0,     7, 4, 1, 0,     7, 6, 5, 3,     7, 6, 5, 3,
 100      7, 6, 5, 4,    15, 6, 5, 4,    11,14, 5, 4,     8,10,13, 4,
 101     15,14, 9, 4,    11,10,13,12,    15,14, 9,12,    11,10,13, 8,
 102     15, 1, 9,12,    11,14,13, 8,     7,10, 9,12,     4, 6, 5, 8,
 103 },
 104 {
 105      3, 0, 0, 0,
 106     11, 2, 0, 0,     7, 7, 3, 0,     7,10, 9, 5,     7, 6, 5, 4,
 107      4, 6, 5, 6,     7, 6, 5, 8,    15, 6, 5, 4,    11,14,13, 4,
 108     15,10, 9, 4,    11,14,13,12,     8,10, 9, 8,    15,14,13,12,
 109     11,10, 9,12,     7,11, 6, 8,     9, 8,10, 1,     7, 6, 5, 4,
 110 },
 111 {
 112     15, 0, 0, 0,
 113     15,14, 0, 0,    11,15,13, 0,     8,12,14,12,    15,10,11,11,
 114     11, 8, 9,10,     9,14,13, 9,     8,10, 9, 8,    15,14,13,13,
 115     11,14,10,12,    15,10,13,12,    11,14, 9,12,     8,10,13, 8,
 116     13, 7, 9,12,     9,12,11,10,     5, 8, 7, 6,     1, 4, 3, 2,
 117 },
 118 {
 119      3, 0, 0, 0,
 120      0, 1, 0, 0,     4, 5, 6, 0,     8, 9,10,11,    12,13,14,15,
 121     16,17,18,19,    20,21,22,23,    24,25,26,27,    28,29,30,31,
 122     32,33,34,35,    36,37,38,39,    40,41,42,43,    44,45,46,47,
 123     48,49,50,51,    52,53,54,55,    56,57,58,59,    60,61,62,63,
 124 }
 125 };
 126
 127 static const uint8_t total_zeros_len[16][16]= {
 128     {1,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9},
 129     {3,3,3,3,3,4,4,4,4,5,5,6,6,6,6},
 130     {4,3,3,3,4,4,3,3,4,5,5,6,5,6},
 131     {5,3,4,4,3,3,3,4,3,4,5,5,5},
 132     {4,4,4,3,3,3,3,3,4,5,4,5},
 133     {6,5,3,3,3,3,3,3,4,3,6},
 134     {6,5,3,3,3,2,3,4,3,6},
 135     {6,4,5,3,2,2,3,3,6},
 136     {6,6,4,2,2,3,2,5},
 137     {5,5,3,2,2,2,4},
 138     {4,4,3,3,1,3},
 139     {4,4,2,1,3},
 140     {3,3,1,2},
 141     {2,2,1},
 142     {1,1},
 143 };
 144
 145 static const uint8_t total_zeros_bits[16][16]= {
 146     {1,3,2,3,2,3,2,3,2,3,2,3,2,3,2,1},
 147     {7,6,5,4,3,5,4,3,2,3,2,3,2,1,0},
 148     {5,7,6,5,4,3,4,3,2,3,2,1,1,0},
 149     {3,7,5,4,6,5,4,3,3,2,2,1,0},
 150     {5,4,3,7,6,5,4,3,2,1,1,0},
 151     {1,1,7,6,5,4,3,2,1,1,0},
 152     {1,1,5,4,3,3,2,1,1,0},
 153     {1,1,1,3,3,2,2,1,0},
 154     {1,0,1,3,2,1,1,1},
 155     {1,0,1,3,2,1,1},
 156     {0,1,1,2,1,3},
 157     {0,1,1,1,1},
 158     {0,1,1,1},
 159     {0,1,1},
 160     {0,1},
 161 };
 162
 163 static const uint8_t chroma_dc_total_zeros_len[3][4]= {
 164     { 1, 2, 3, 3,},
 165     { 1, 2, 2, 0,},
 166     { 1, 1, 0, 0,},
 167 };
 168
 169 static const uint8_t chroma_dc_total_zeros_bits[3][4]= {
 170     { 1, 1, 1, 0,},
 171     { 1, 1, 0, 0,},
 172     { 1, 0, 0, 0,},
 173 };
 174
 175 static const uint8_t run_len[7][16]={
 176     {1,1},
 177     {1,2,2},
 178     {2,2,2,2},
 179     {2,2,2,3,3},
 180     {2,2,3,3,3,3},
 181     {2,3,3,3,3,3,3},
 182     {3,3,3,3,3,3,3,4,5,6,7,8,9,10,11},
 183 };
 184
 185 static const uint8_t run_bits[7][16]={
 186     {1,0},
 187     {1,1,0},
 188     {3,2,1,0},
 189     {3,2,1,1,0},
 190     {3,2,3,2,1,0},
 191     {3,0,1,3,2,5,4},
 192     {7,6,5,4,3,2,1,1,1,1,1,1,1,1,1},
 193 };
 194
 195 static VLC coeff_token_vlc[4];
 196 static VLC_TYPE coeff_token_vlc_tables[520+332+280+256][2];
 197 static const int coeff_token_vlc_tables_size[4]={520,332,280,256};
 198
 199 static VLC chroma_dc_coeff_token_vlc;
 200 static VLC_TYPE chroma_dc_coeff_token_vlc_table[256][2];
 201 static const int chroma_dc_coeff_token_vlc_table_size = 256;
 202
 203 static VLC total_zeros_vlc[15];
 204 static VLC_TYPE total_zeros_vlc_tables[15][512][2];
 205 static const int total_zeros_vlc_tables_size = 512;
 206
 207 static VLC chroma_dc_total_zeros_vlc[3];
 208 static VLC_TYPE chroma_dc_total_zeros_vlc_tables[3][8][2];
 209 static const int chroma_dc_total_zeros_vlc_tables_size = 8;
 210
 211 static VLC run_vlc[6];
 212 static VLC_TYPE run_vlc_tables[6][8][2];
 213 static const int run_vlc_tables_size = 8;
 214
 215 static VLC run7_vlc;
 216 static VLC_TYPE run7_vlc_table[96][2];
 217 static const int run7_vlc_table_size = 96;
 218
 219 #define LEVEL_TAB_BITS 8
 220 static int8_t cavlc_level_tab[7][1<<LEVEL_TAB_BITS][2];
 221
 222
 223 /**
 224  * gets the predicted number of non-zero coefficients.
 225  * @param n block index
 226  */
 227 static inline int pred_non_zero_count(H264Context *h, int n){
 228     const int index8= scan8[n];
 229     const int left= h->non_zero_count_cache[index8 - 1];
 230     const int top = h->non_zero_count_cache[index8 - 8];
 231     int i= left + top;
 232
 233     if(i<64) i= (i+1)>>1;
 234
 235     tprintf(h->s.avctx, "pred_nnz L%X T%X n%d s%d P%X\n", left, top, n, scan8[n], i&31);
 236
 237     return i&31;
 238 }
 239
 240 static av_cold void init_cavlc_level_tab(void){
 241     int suffix_length, mask;
 242     unsigned int i;
 243
 244     for(suffix_length=0; suffix_length<7; suffix_length++){
 245         for(i=0; i<(1<<LEVEL_TAB_BITS); i++){
 246             int prefix= LEVEL_TAB_BITS - av_log2(2*i);
 247             int level_code= (prefix<<suffix_length) + (i>>(LEVEL_TAB_BITS-prefix-1-suffix_length)) - (1<<suffix_length);
 248
 249             mask= -(level_code&1);
 250             level_code= (((2+level_code)>>1) ^ mask) - mask;
 251             if(prefix + 1 + suffix_length <= LEVEL_TAB_BITS){
 252                 cavlc_level_tab[suffix_length][i][0]= level_code;
 253                 cavlc_level_tab[suffix_length][i][1]= prefix + 1 + suffix_length;
 254             }else if(prefix + 1 <= LEVEL_TAB_BITS){
 255                 cavlc_level_tab[suffix_length][i][0]= prefix+100;
 256                 cavlc_level_tab[suffix_length][i][1]= prefix + 1;
 257             }else{
 258                 cavlc_level_tab[suffix_length][i][0]= LEVEL_TAB_BITS+100;
 259                 cavlc_level_tab[suffix_length][i][1]= LEVEL_TAB_BITS;
 260             }
 261         }
 262     }
 263 }
 264
 265 av_cold void ff_h264_decode_init_vlc(void){
 266     static int done = 0;
 267
 268     if (!done) {
 269         int i;
 270         int offset;
 271         done = 1;
 272
 273         chroma_dc_coeff_token_vlc.table = chroma_dc_coeff_token_vlc_table;
 274         chroma_dc_coeff_token_vlc.table_allocated = chroma_dc_coeff_token_vlc_table_size;
 275         init_vlc(&chroma_dc_coeff_token_vlc, CHROMA_DC_COEFF_TOKEN_VLC_BITS, 4*5,
 276                  &chroma_dc_coeff_token_len [0], 1, 1,
 277                  &chroma_dc_coeff_token_bits[0], 1, 1,
 278                  INIT_VLC_USE_NEW_STATIC);
 279
 280         offset = 0;
 281         for(i=0; i<4; i++){
 282             coeff_token_vlc[i].table = coeff_token_vlc_tables+offset;
 283             coeff_token_vlc[i].table_allocated = coeff_token_vlc_tables_size[i];
 284             init_vlc(&coeff_token_vlc[i], COEFF_TOKEN_VLC_BITS, 4*17,
 285                      &coeff_token_len [i][0], 1, 1,
 286                      &coeff_token_bits[i][0], 1, 1,
 287                      INIT_VLC_USE_NEW_STATIC);
 288             offset += coeff_token_vlc_tables_size[i];
 289         }
 290         /*
 291          * This is a one time safety check to make sure that
 292          * the packed static coeff_token_vlc table sizes
 293          * were initialized correctly.
 294          */
 295         assert(offset == FF_ARRAY_ELEMS(coeff_token_vlc_tables));
 296
 297         for(i=0; i<3; i++){
 298             chroma_dc_total_zeros_vlc[i].table = chroma_dc_total_zeros_vlc_tables[i];
 299             chroma_dc_total_zeros_vlc[i].table_allocated = chroma_dc_total_zeros_vlc_tables_size;
 300             init_vlc(&chroma_dc_total_zeros_vlc[i],
 301                      CHROMA_DC_TOTAL_ZEROS_VLC_BITS, 4,
 302                      &chroma_dc_total_zeros_len [i][0], 1, 1,
 303                      &chroma_dc_total_zeros_bits[i][0], 1, 1,
 304                      INIT_VLC_USE_NEW_STATIC);
 305         }
 306         for(i=0; i<15; i++){
 307             total_zeros_vlc[i].table = total_zeros_vlc_tables[i];
 308             total_zeros_vlc[i].table_allocated = total_zeros_vlc_tables_size;
 309             init_vlc(&total_zeros_vlc[i],
 310                      TOTAL_ZEROS_VLC_BITS, 16,
 311                      &total_zeros_len [i][0], 1, 1,
 312                      &total_zeros_bits[i][0], 1, 1,
 313                      INIT_VLC_USE_NEW_STATIC);
 314         }
 315
 316         for(i=0; i<6; i++){
 317             run_vlc[i].table = run_vlc_tables[i];
 318             run_vlc[i].table_allocated = run_vlc_tables_size;
 319             init_vlc(&run_vlc[i],
 320                      RUN_VLC_BITS, 7,
 321                      &run_len [i][0], 1, 1,
 322                      &run_bits[i][0], 1, 1,
 323                      INIT_VLC_USE_NEW_STATIC);
 324         }
 325         run7_vlc.table = run7_vlc_table,
 326         run7_vlc.table_allocated = run7_vlc_table_size;
 327         init_vlc(&run7_vlc, RUN7_VLC_BITS, 16,
 328                  &run_len [6][0], 1, 1,
 329                  &run_bits[6][0], 1, 1,
 330                  INIT_VLC_USE_NEW_STATIC);
 331
 332         init_cavlc_level_tab();
 333     }
 334 }
 335
 336 /**
 337  *
 338  */
 339 static inline int get_level_prefix(GetBitContext *gb){
 340     unsigned int buf;
 341     int log;
 342
 343     OPEN_READER(re, gb);
 344     UPDATE_CACHE(re, gb);
 345     buf=GET_CACHE(re, gb);
 346
 347     log= 32 - av_log2(buf);
 348 #ifdef TRACE
 349     print_bin(buf>>(32-log), log);
 350     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d lpr @%5d in %s get_level_prefix\n", buf>>(32-log), log, log-1, get_bits_count(gb), __FILE__);
 351 #endif
 352
 353     LAST_SKIP_BITS(re, gb, log);
 354     CLOSE_READER(re, gb);
 355
 356     return log-1;
 357 }
 358
 359 /**
 360  * decodes a residual block.
 361  * @param n block index
 362  * @param scantable scantable
 363  * @param max_coeff number of coefficients in the block
 364  * @return <0 if an error occurred
 365  */
 366 static int decode_residual(H264Context *h, GetBitContext *gb, DCTELEM *block, int n, const uint8_t *scantable, const uint32_t *qmul, int max_coeff){
 367     MpegEncContext * const s = &h->s;
 368     static const int coeff_token_table_index[17]= {0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3};
 369     int level[16];
 370     int zeros_left, coeff_num, coeff_token, total_coeff, i, j, trailing_ones, run_before;
 371
 372     //FIXME put trailing_onex into the context
 373
 374     if(n == CHROMA_DC_BLOCK_INDEX){
 375         coeff_token= get_vlc2(gb, chroma_dc_coeff_token_vlc.table, CHROMA_DC_COEFF_TOKEN_VLC_BITS, 1);
 376         total_coeff= coeff_token>>2;
 377     }else{
 378         if(n == LUMA_DC_BLOCK_INDEX){
 379             total_coeff= pred_non_zero_count(h, 0);
 380             coeff_token= get_vlc2(gb, coeff_token_vlc[ coeff_token_table_index[total_coeff] ].table, COEFF_TOKEN_VLC_BITS, 2);
 381             total_coeff= coeff_token>>2;
 382         }else{
 383             total_coeff= pred_non_zero_count(h, n);
 384             coeff_token= get_vlc2(gb, coeff_token_vlc[ coeff_token_table_index[total_coeff] ].table, COEFF_TOKEN_VLC_BITS, 2);
 385             total_coeff= coeff_token>>2;
 386             h->non_zero_count_cache[ scan8[n] ]= total_coeff;
 387         }
 388     }
 389
 390     //FIXME set last_non_zero?
 391
 392     if(total_coeff==0)
 393         return 0;
 394     if(total_coeff > (unsigned)max_coeff) {
 395         av_log(h->s.avctx, AV_LOG_ERROR, "corrupted macroblock %d %d (total_coeff=%d)\n", s->mb_x, s->mb_y, total_coeff);
 396         return -1;
 397     }
 398
 399     trailing_ones= coeff_token&3;
 400     tprintf(h->s.avctx, "trailing:%d, total:%d\n", trailing_ones, total_coeff);
 401     assert(total_coeff<=16);
 402
 403     i = show_bits(gb, 3);
 404     skip_bits(gb, trailing_ones);
 405     level[0] = 1-((i&4)>>1);
 406     level[1] = 1-((i&2)   );
 407     level[2] = 1-((i&1)<<1);
 408
 409     if(trailing_ones<total_coeff) {
 410         int mask, prefix;
 411         int suffix_length = total_coeff > 10 && trailing_ones < 3;
 412         int bitsi= show_bits(gb, LEVEL_TAB_BITS);
 413         int level_code= cavlc_level_tab[suffix_length][bitsi][0];
 414
 415         skip_bits(gb, cavlc_level_tab[suffix_length][bitsi][1]);
 416         if(level_code >= 100){
 417             prefix= level_code - 100;
 418             if(prefix == LEVEL_TAB_BITS)
 419                 prefix += get_level_prefix(gb);
 420
 421             //first coefficient has suffix_length equal to 0 or 1
 422             if(prefix<14){ //FIXME try to build a large unified VLC table for all this
 423                 if(suffix_length)
 424                     level_code= (prefix<<1) + get_bits1(gb); //part
 425                 else
 426                     level_code= prefix; //part
 427             }else if(prefix==14){
 428                 if(suffix_length)
 429                     level_code= (prefix<<1) + get_bits1(gb); //part
 430                 else
 431                     level_code= prefix + get_bits(gb, 4); //part
 432             }else{
 433                 level_code= 30 + get_bits(gb, prefix-3); //part
 434                 if(prefix>=16)
 435                     level_code += (1<<(prefix-3))-4096;
 436             }
 437
 438             if(trailing_ones < 3) level_code += 2;
 439
 440             suffix_length = 2;
 441             mask= -(level_code&1);
 442             level[trailing_ones]= (((2+level_code)>>1) ^ mask) - mask;
 443         }else{
 444             if(trailing_ones < 3) level_code += (level_code>>31)|1;
 445
 446             suffix_length = 1;
 447             if(level_code + 3U > 6U)
 448                 suffix_length++;
 449             level[trailing_ones]= level_code;
 450         }
 451
 452         //remaining coefficients have suffix_length > 0
 453         for(i=trailing_ones+1;i<total_coeff;i++) {
 454             static const unsigned int suffix_limit[7] = {0,3,6,12,24,48,INT_MAX };
 455             int bitsi= show_bits(gb, LEVEL_TAB_BITS);
 456             level_code= cavlc_level_tab[suffix_length][bitsi][0];
 457
 458             skip_bits(gb, cavlc_level_tab[suffix_length][bitsi][1]);
 459             if(level_code >= 100){
 460                 prefix= level_code - 100;
 461                 if(prefix == LEVEL_TAB_BITS){
 462                     prefix += get_level_prefix(gb);
 463                 }
 464                 if(prefix<15){
 465                     level_code = (prefix<<suffix_length) + get_bits(gb, suffix_length);
 466                 }else{
 467                     level_code = (15<<suffix_length) + get_bits(gb, prefix-3);
 468                     if(prefix>=16)
 469                         level_code += (1<<(prefix-3))-4096;
 470                 }
 471                 mask= -(level_code&1);
 472                 level_code= (((2+level_code)>>1) ^ mask) - mask;
 473             }
 474             level[i]= level_code;
 475
 476             if(suffix_limit[suffix_length] + level_code > 2U*suffix_limit[suffix_length])
 477                 suffix_length++;
 478         }
 479     }
 480
 481     if(total_coeff == max_coeff)
 482         zeros_left=0;
 483     else{
 484         if(n == CHROMA_DC_BLOCK_INDEX)
 485             zeros_left= get_vlc2(gb, chroma_dc_total_zeros_vlc[ total_coeff-1 ].table, CHROMA_DC_TOTAL_ZEROS_VLC_BITS, 1);
 486         else
 487             zeros_left= get_vlc2(gb, total_zeros_vlc[ total_coeff-1 ].table, TOTAL_ZEROS_VLC_BITS, 1);
 488     }
 489
 490     coeff_num = zeros_left + total_coeff - 1;
 491     j = scantable[coeff_num];
 492     if(n > 24){
 493         block[j] = level[0];
 494         for(i=1;i<total_coeff;i++) {
 495             if(zeros_left <= 0)
 496                 run_before = 0;
 497             else if(zeros_left < 7){
 498                 run_before= get_vlc2(gb, run_vlc[zeros_left-1].table, RUN_VLC_BITS, 1);
 499             }else{
 500                 run_before= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2);
 501             }
 502             zeros_left -= run_before;
 503             coeff_num -= 1 + run_before;
 504             j= scantable[ coeff_num ];
 505
 506             block[j]= level[i];
 507         }
 508     }else{
 509         block[j] = (level[0] * qmul[j] + 32)>>6;
 510         for(i=1;i<total_coeff;i++) {
 511             if(zeros_left <= 0)
 512                 run_before = 0;
 513             else if(zeros_left < 7){
 514                 run_before= get_vlc2(gb, run_vlc[zeros_left-1].table, RUN_VLC_BITS, 1);
 515             }else{
 516                 run_before= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2);
 517             }
 518             zeros_left -= run_before;
 519             coeff_num -= 1 + run_before;
 520             j= scantable[ coeff_num ];
 521
 522             block[j]= (level[i] * qmul[j] + 32)>>6;
 523         }
 524     }
 525
 526     if(zeros_left<0){
 527         av_log(h->s.avctx, AV_LOG_ERROR, "negative number of zero coeffs at %d %d\n", s->mb_x, s->mb_y);
 528         return -1;
 529     }
 530
 531     return 0;
 532 }
 533
 534 int ff_h264_decode_mb_cavlc(H264Context *h){
 535     MpegEncContext * const s = &h->s;
 536     int mb_xy;
 537     int partition_count;
 538     unsigned int mb_type, cbp;
 539     int dct8x8_allowed= h->pps.transform_8x8_mode;
 540
 541     mb_xy = h->mb_xy = s->mb_x + s->mb_y*s->mb_stride;
 542
 543     tprintf(s->avctx, "pic:%d mb:%d/%d\n", h->frame_num, s->mb_x, s->mb_y);
 544     cbp = 0; /* avoid warning. FIXME: find a solution without slowing
 545                 down the code */
 546     if(h->slice_type_nos != FF_I_TYPE){
 547         if(s->mb_skip_run==-1)
 548             s->mb_skip_run= get_ue_golomb(&s->gb);
 549
 550         if (s->mb_skip_run--) {
 551             if(FRAME_MBAFF && (s->mb_y&1) == 0){
 552                 if(s->mb_skip_run==0)
 553                     h->mb_mbaff = h->mb_field_decoding_flag = get_bits1(&s->gb);
 554                 else
 555                     predict_field_decoding_flag(h);
 556             }
 557             decode_mb_skip(h);
 558             return 0;
 559         }
 560     }
 561     if(FRAME_MBAFF){
 562         if( (s->mb_y&1) == 0 )
 563             h->mb_mbaff = h->mb_field_decoding_flag = get_bits1(&s->gb);
 564     }
 565
 566     h->prev_mb_skipped= 0;
 567
 568     mb_type= get_ue_golomb(&s->gb);
 569     if(h->slice_type_nos == FF_B_TYPE){
 570         if(mb_type < 23){
 571             partition_count= b_mb_type_info[mb_type].partition_count;
 572             mb_type=         b_mb_type_info[mb_type].type;
 573         }else{
 574             mb_type -= 23;
 575             goto decode_intra_mb;
 576         }
 577     }else if(h->slice_type_nos == FF_P_TYPE){
 578         if(mb_type < 5){
 579             partition_count= p_mb_type_info[mb_type].partition_count;
 580             mb_type=         p_mb_type_info[mb_type].type;
 581         }else{
 582             mb_type -= 5;
 583             goto decode_intra_mb;
 584         }
 585     }else{
 586        assert(h->slice_type_nos == FF_I_TYPE);
 587         if(h->slice_type == FF_SI_TYPE && mb_type)
 588             mb_type--;
 589 decode_intra_mb:
 590         if(mb_type > 25){
 591             av_log(h->s.avctx, AV_LOG_ERROR, "mb_type %d in %c slice too large at %d %d\n", mb_type, av_get_pict_type_char(h->slice_type), s->mb_x, s->mb_y);
 592             return -1;
 593         }
 594         partition_count=0;
 595         cbp= i_mb_type_info[mb_type].cbp;
 596         h->intra16x16_pred_mode= i_mb_type_info[mb_type].pred_mode;
 597         mb_type= i_mb_type_info[mb_type].type;
 598     }
 599
 600     if(MB_FIELD)
 601         mb_type |= MB_TYPE_INTERLACED;
 602
 603     h->slice_table[ mb_xy ]= h->slice_num;
 604
 605     if(IS_INTRA_PCM(mb_type)){
 606         unsigned int x;
 607
 608         // We assume these blocks are very rare so we do not optimize it.
 609         align_get_bits(&s->gb);
 610
 611         // The pixels are stored in the same order as levels in h->mb array.
 612         for(x=0; x < (CHROMA ? 384 : 256); x++){
 613             ((uint8_t*)h->mb)[x]= get_bits(&s->gb, 8);
 614         }
 615
 616         // In deblocking, the quantizer is 0
 617         s->current_picture.qscale_table[mb_xy]= 0;
 618         // All coeffs are present
 619         memset(h->non_zero_count[mb_xy], 16, 32);
 620
 621         s->current_picture.mb_type[mb_xy]= mb_type;
 622         return 0;
 623     }
 624
 625     if(MB_MBAFF){
 626         h->ref_count[0] <<= 1;
 627         h->ref_count[1] <<= 1;
 628     }
 629
 630     fill_decode_caches(h, mb_type);
 631
 632     //mb_pred
 633     if(IS_INTRA(mb_type)){
 634         int pred_mode;
 635 //            init_top_left_availability(h);
 636         if(IS_INTRA4x4(mb_type)){
 637             int i;
 638             int di = 1;
 639             if(dct8x8_allowed && get_bits1(&s->gb)){
 640                 mb_type |= MB_TYPE_8x8DCT;
 641                 di = 4;
 642             }
 643
 644 //                fill_intra4x4_pred_table(h);
 645             for(i=0; i<16; i+=di){
 646                 int mode= pred_intra_mode(h, i);
 647
 648                 if(!get_bits1(&s->gb)){
 649                     const int rem_mode= get_bits(&s->gb, 3);
 650                     mode = rem_mode + (rem_mode >= mode);
 651                 }
 652
 653                 if(di==4)
 654                     fill_rectangle( &h->intra4x4_pred_mode_cache[ scan8[i] ], 2, 2, 8, mode, 1 );
 655                 else
 656                     h->intra4x4_pred_mode_cache[ scan8[i] ] = mode;
 657             }
 658             ff_h264_write_back_intra_pred_mode(h);
 659             if( ff_h264_check_intra4x4_pred_mode(h) < 0)
 660                 return -1;
 661         }else{
 662             h->intra16x16_pred_mode= ff_h264_check_intra_pred_mode(h, h->intra16x16_pred_mode);
 663             if(h->intra16x16_pred_mode < 0)
 664                 return -1;
 665         }
 666         if(CHROMA){
 667             pred_mode= ff_h264_check_intra_pred_mode(h, get_ue_golomb_31(&s->gb));
 668             if(pred_mode < 0)
 669                 return -1;
 670             h->chroma_pred_mode= pred_mode;
 671         }
 672     }else if(partition_count==4){
 673         int i, j, sub_partition_count[4], list, ref[2][4];
 674
 675         if(h->slice_type_nos == FF_B_TYPE){
 676             for(i=0; i<4; i++){
 677                 h->sub_mb_type[i]= get_ue_golomb_31(&s->gb);
 678                 if(h->sub_mb_type[i] >=13){
 679                     av_log(h->s.avctx, AV_LOG_ERROR, "B sub_mb_type %u out of range at %d %d\n", h->sub_mb_type[i], s->mb_x, s->mb_y);
 680                     return -1;
 681                 }
 682                 sub_partition_count[i]= b_sub_mb_type_info[ h->sub_mb_type[i] ].partition_count;
 683                 h->sub_mb_type[i]=      b_sub_mb_type_info[ h->sub_mb_type[i] ].type;
 684             }
 685             if( IS_DIRECT(h->sub_mb_type[0]|h->sub_mb_type[1]|h->sub_mb_type[2]|h->sub_mb_type[3])) {
 686                 ff_h264_pred_direct_motion(h, &mb_type);
 687                 h->ref_cache[0][scan8[4]] =
 688                 h->ref_cache[1][scan8[4]] =
 689                 h->ref_cache[0][scan8[12]] =
 690                 h->ref_cache[1][scan8[12]] = PART_NOT_AVAILABLE;
 691             }
 692         }else{
 693             assert(h->slice_type_nos == FF_P_TYPE); //FIXME SP correct ?
 694             for(i=0; i<4; i++){
 695                 h->sub_mb_type[i]= get_ue_golomb_31(&s->gb);
 696                 if(h->sub_mb_type[i] >=4){
 697                     av_log(h->s.avctx, AV_LOG_ERROR, "P sub_mb_type %u out of range at %d %d\n", h->sub_mb_type[i], s->mb_x, s->mb_y);
 698                     return -1;
 699                 }
 700                 sub_partition_count[i]= p_sub_mb_type_info[ h->sub_mb_type[i] ].partition_count;
 701                 h->sub_mb_type[i]=      p_sub_mb_type_info[ h->sub_mb_type[i] ].type;
 702             }
 703         }
 704
 705         for(list=0; list<h->list_count; list++){
 706             int ref_count= IS_REF0(mb_type) ? 1 : h->ref_count[list];
 707             for(i=0; i<4; i++){
 708                 if(IS_DIRECT(h->sub_mb_type[i])) continue;
 709                 if(IS_DIR(h->sub_mb_type[i], 0, list)){
 710                     unsigned int tmp;
 711                     if(ref_count == 1){
 712                         tmp= 0;
 713                     }else if(ref_count == 2){
 714                         tmp= get_bits1(&s->gb)^1;
 715                     }else{
 716                         tmp= get_ue_golomb_31(&s->gb);
 717                         if(tmp>=ref_count){
 718                             av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", tmp);
 719                             return -1;
 720                         }
 721                     }
 722                     ref[list][i]= tmp;
 723                 }else{
 724                  //FIXME
 725                     ref[list][i] = -1;
 726                 }
 727             }
 728         }
 729
 730         if(dct8x8_allowed)
 731             dct8x8_allowed = get_dct8x8_allowed(h);
 732
 733         for(list=0; list<h->list_count; list++){
 734             for(i=0; i<4; i++){
 735                 if(IS_DIRECT(h->sub_mb_type[i])) {
 736                     h->ref_cache[list][ scan8[4*i] ] = h->ref_cache[list][ scan8[4*i]+1 ];
 737                     continue;
 738                 }
 739                 h->ref_cache[list][ scan8[4*i]   ]=h->ref_cache[list][ scan8[4*i]+1 ]=
 740                 h->ref_cache[list][ scan8[4*i]+8 ]=h->ref_cache[list][ scan8[4*i]+9 ]= ref[list][i];
 741
 742                 if(IS_DIR(h->sub_mb_type[i], 0, list)){
 743                     const int sub_mb_type= h->sub_mb_type[i];
 744                     const int block_width= (sub_mb_type & (MB_TYPE_16x16|MB_TYPE_16x8)) ? 2 : 1;
 745                     for(j=0; j<sub_partition_count[i]; j++){
 746                         int mx, my;
 747                         const int index= 4*i + block_width*j;
 748                         int16_t (* mv_cache)[2]= &h->mv_cache[list][ scan8[index] ];
 749                         pred_motion(h, index, block_width, list, h->ref_cache[list][ scan8[index] ], &mx, &my);
 750                         mx += get_se_golomb(&s->gb);
 751                         my += get_se_golomb(&s->gb);
 752                         tprintf(s->avctx, "final mv:%d %d\n", mx, my);
 753
 754                         if(IS_SUB_8X8(sub_mb_type)){
 755                             mv_cache[ 1 ][0]=
 756                             mv_cache[ 8 ][0]= mv_cache[ 9 ][0]= mx;
 757                             mv_cache[ 1 ][1]=
 758                             mv_cache[ 8 ][1]= mv_cache[ 9 ][1]= my;
 759                         }else if(IS_SUB_8X4(sub_mb_type)){
 760                             mv_cache[ 1 ][0]= mx;
 761                             mv_cache[ 1 ][1]= my;
 762                         }else if(IS_SUB_4X8(sub_mb_type)){
 763                             mv_cache[ 8 ][0]= mx;
 764                             mv_cache[ 8 ][1]= my;
 765                         }
 766                         mv_cache[ 0 ][0]= mx;
 767                         mv_cache[ 0 ][1]= my;
 768                     }
 769                 }else{
 770                     uint32_t *p= (uint32_t *)&h->mv_cache[list][ scan8[4*i] ][0];
 771                     p[0] = p[1]=
 772                     p[8] = p[9]= 0;
 773                 }
 774             }
 775         }
 776     }else if(IS_DIRECT(mb_type)){
 777         ff_h264_pred_direct_motion(h, &mb_type);
 778         dct8x8_allowed &= h->sps.direct_8x8_inference_flag;
 779     }else{
 780         int list, mx, my, i;
 781          //FIXME we should set ref_idx_l? to 0 if we use that later ...
 782         if(IS_16X16(mb_type)){
 783             for(list=0; list<h->list_count; list++){
 784                     unsigned int val;
 785                     if(IS_DIR(mb_type, 0, list)){
 786                         if(h->ref_count[list]==1){
 787                             val= 0;
 788                         }else if(h->ref_count[list]==2){
 789                             val= get_bits1(&s->gb)^1;
 790                         }else{
 791                             val= get_ue_golomb_31(&s->gb);
 792                             if(val >= h->ref_count[list]){
 793                                 av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);
 794                                 return -1;
 795                             }
 796                         }
 797                     }else
 798                         val= LIST_NOT_USED&0xFF;
 799                     fill_rectangle(&h->ref_cache[list][ scan8[0] ], 4, 4, 8, val, 1);
 800             }
 801             for(list=0; list<h->list_count; list++){
 802                 unsigned int val;
 803                 if(IS_DIR(mb_type, 0, list)){
 804                     pred_motion(h, 0, 4, list, h->ref_cache[list][ scan8[0] ], &mx, &my);
 805                     mx += get_se_golomb(&s->gb);
 806                     my += get_se_golomb(&s->gb);
 807                     tprintf(s->avctx, "final mv:%d %d\n", mx, my);
 808
 809                     val= pack16to32(mx,my);
 810                 }else
 811                     val=0;
 812                 fill_rectangle(h->mv_cache[list][ scan8[0] ], 4, 4, 8, val, 4);
 813             }
 814         }
 815         else if(IS_16X8(mb_type)){
 816             for(list=0; list<h->list_count; list++){
 817                     for(i=0; i<2; i++){
 818                         unsigned int val;
 819                         if(IS_DIR(mb_type, i, list)){
 820                             if(h->ref_count[list] == 1){
 821                                 val= 0;
 822                             }else if(h->ref_count[list] == 2){
 823                                 val= get_bits1(&s->gb)^1;
 824                             }else{
 825                                 val= get_ue_golomb_31(&s->gb);
 826                                 if(val >= h->ref_count[list]){
 827                                     av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);
 828                                     return -1;
 829                                 }
 830                             }
 831                         }else
 832                             val= LIST_NOT_USED&0xFF;
 833                         fill_rectangle(&h->ref_cache[list][ scan8[0] + 16*i ], 4, 2, 8, val, 1);
 834                     }
 835             }
 836             for(list=0; list<h->list_count; list++){
 837                 for(i=0; i<2; i++){
 838                     unsigned int val;
 839                     if(IS_DIR(mb_type, i, list)){
 840                         pred_16x8_motion(h, 8*i, list, h->ref_cache[list][scan8[0] + 16*i], &mx, &my);
 841                         mx += get_se_golomb(&s->gb);
 842                         my += get_se_golomb(&s->gb);
 843                         tprintf(s->avctx, "final mv:%d %d\n", mx, my);
 844
 845                         val= pack16to32(mx,my);
 846                     }else
 847                         val=0;
 848                     fill_rectangle(h->mv_cache[list][ scan8[0] + 16*i ], 4, 2, 8, val, 4);
 849                 }
 850             }
 851         }else{
 852             assert(IS_8X16(mb_type));
 853             for(list=0; list<h->list_count; list++){
 854                     for(i=0; i<2; i++){
 855                         unsigned int val;
 856                         if(IS_DIR(mb_type, i, list)){ //FIXME optimize
 857                             if(h->ref_count[list]==1){
 858                                 val= 0;
 859                             }else if(h->ref_count[list]==2){
 860                                 val= get_bits1(&s->gb)^1;
 861                             }else{
 862                                 val= get_ue_golomb_31(&s->gb);
 863                                 if(val >= h->ref_count[list]){
 864                                     av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);
 865                                     return -1;
 866                                 }
 867                             }
 868                         }else
 869                             val= LIST_NOT_USED&0xFF;
 870                         fill_rectangle(&h->ref_cache[list][ scan8[0] + 2*i ], 2, 4, 8, val, 1);
 871                     }
 872             }
 873             for(list=0; list<h->list_count; list++){
 874                 for(i=0; i<2; i++){
 875                     unsigned int val;
 876                     if(IS_DIR(mb_type, i, list)){
 877                         pred_8x16_motion(h, i*4, list, h->ref_cache[list][ scan8[0] + 2*i ], &mx, &my);
 878                         mx += get_se_golomb(&s->gb);
 879                         my += get_se_golomb(&s->gb);
 880                         tprintf(s->avctx, "final mv:%d %d\n", mx, my);
 881
 882                         val= pack16to32(mx,my);
 883                     }else
 884                         val=0;
 885                     fill_rectangle(h->mv_cache[list][ scan8[0] + 2*i ], 2, 4, 8, val, 4);
 886                 }
 887             }
 888         }
 889     }
 890
 891     if(IS_INTER(mb_type))
 892         write_back_motion(h, mb_type);
 893
 894     if(!IS_INTRA16x16(mb_type)){
 895         cbp= get_ue_golomb(&s->gb);
 896         if(cbp > 47){
 897             av_log(h->s.avctx, AV_LOG_ERROR, "cbp too large (%u) at %d %d\n", cbp, s->mb_x, s->mb_y);
 898             return -1;
 899         }
 900
 901         if(CHROMA){
 902             if(IS_INTRA4x4(mb_type)) cbp= golomb_to_intra4x4_cbp[cbp];
 903             else                     cbp= golomb_to_inter_cbp   [cbp];
 904         }else{
 905             if(IS_INTRA4x4(mb_type)) cbp= golomb_to_intra4x4_cbp_gray[cbp];
 906             else                     cbp= golomb_to_inter_cbp_gray[cbp];
 907         }
 908     }
 909
 910     if(dct8x8_allowed && (cbp&15) && !IS_INTRA(mb_type)){
 911         if(get_bits1(&s->gb)){
 912             mb_type |= MB_TYPE_8x8DCT;
 913         }
 914     }
 915     h->cbp=
 916     h->cbp_table[mb_xy]= cbp;
 917     s->current_picture.mb_type[mb_xy]= mb_type;
 918
 919     if(cbp || IS_INTRA16x16(mb_type)){
 920         int i8x8, i4x4, chroma_idx;
 921         int dquant;
 922         GetBitContext *gb= IS_INTRA(mb_type) ? h->intra_gb_ptr : h->inter_gb_ptr;
 923         const uint8_t *scan, *scan8x8, *dc_scan;
 924
 925 //        fill_non_zero_count_cache(h);
 926
 927         if(IS_INTERLACED(mb_type)){
 928             scan8x8= s->qscale ? h->field_scan8x8_cavlc : h->field_scan8x8_cavlc_q0;
 929             scan= s->qscale ? h->field_scan : h->field_scan_q0;
 930             dc_scan= luma_dc_field_scan;
 931         }else{
 932             scan8x8= s->qscale ? h->zigzag_scan8x8_cavlc : h->zigzag_scan8x8_cavlc_q0;
 933             scan= s->qscale ? h->zigzag_scan : h->zigzag_scan_q0;
 934             dc_scan= luma_dc_zigzag_scan;
 935         }
 936
 937         dquant= get_se_golomb(&s->gb);
 938
 939         if( dquant > 25 || dquant < -26 ){
 940             av_log(h->s.avctx, AV_LOG_ERROR, "dquant out of range (%d) at %d %d\n", dquant, s->mb_x, s->mb_y);
 941             return -1;
 942         }
 943
 944         s->qscale += dquant;
 945         if(((unsigned)s->qscale) > 51){
 946             if(s->qscale<0) s->qscale+= 52;
 947             else            s->qscale-= 52;
 948         }
 949
 950         h->chroma_qp[0]= get_chroma_qp(h, 0, s->qscale);
 951         h->chroma_qp[1]= get_chroma_qp(h, 1, s->qscale);
 952         if(IS_INTRA16x16(mb_type)){
 953             if( decode_residual(h, h->intra_gb_ptr, h->mb, LUMA_DC_BLOCK_INDEX, dc_scan, h->dequant4_coeff[0][s->qscale], 16) < 0){
 954                 return -1; //FIXME continue if partitioned and other return -1 too
 955             }
 956
 957             assert((cbp&15) == 0 || (cbp&15) == 15);
 958
 959             if(cbp&15){
 960                 for(i8x8=0; i8x8<4; i8x8++){
 961                     for(i4x4=0; i4x4<4; i4x4++){
 962                         const int index= i4x4 + 4*i8x8;
 963                         if( decode_residual(h, h->intra_gb_ptr, h->mb + 16*index, index, scan + 1, h->dequant4_coeff[0][s->qscale], 15) < 0 ){
 964                             return -1;
 965                         }
 966                     }
 967                 }
 968             }else{
 969                 fill_rectangle(&h->non_zero_count_cache[scan8[0]], 4, 4, 8, 0, 1);
 970             }
 971         }else{
 972             for(i8x8=0; i8x8<4; i8x8++){
 973                 if(cbp & (1<<i8x8)){
 974                     if(IS_8x8DCT(mb_type)){
 975                         DCTELEM *buf = &h->mb[64*i8x8];
 976                         uint8_t *nnz;
 977                         for(i4x4=0; i4x4<4; i4x4++){
 978                             if( decode_residual(h, gb, buf, i4x4+4*i8x8, scan8x8+16*i4x4,
 979                                                 h->dequant8_coeff[IS_INTRA( mb_type ) ? 0:1][s->qscale], 16) <0 )
 980                                 return -1;
 981                         }
 982                         nnz= &h->non_zero_count_cache[ scan8[4*i8x8] ];
 983                         nnz[0] += nnz[1] + nnz[8] + nnz[9];
 984                     }else{
 985                         for(i4x4=0; i4x4<4; i4x4++){
 986                             const int index= i4x4 + 4*i8x8;
 987
 988                             if( decode_residual(h, gb, h->mb + 16*index, index, scan, h->dequant4_coeff[IS_INTRA( mb_type ) ? 0:3][s->qscale], 16) <0 ){
 989                                 return -1;
 990                             }
 991                         }
 992                     }
 993                 }else{
 994                     uint8_t * const nnz= &h->non_zero_count_cache[ scan8[4*i8x8] ];
 995                     nnz[0] = nnz[1] = nnz[8] = nnz[9] = 0;
 996                 }
 997             }
 998         }
 999
1000         if(cbp&0x30){
1001             for(chroma_idx=0; chroma_idx<2; chroma_idx++)
1002                 if( decode_residual(h, gb, h->mb + 256 + 16*4*chroma_idx, CHROMA_DC_BLOCK_INDEX, chroma_dc_scan, NULL, 4) < 0){
1003                     return -1;
1004                 }
1005         }
1006
1007         if(cbp&0x20){
1008             for(chroma_idx=0; chroma_idx<2; chroma_idx++){
1009                 const uint32_t *qmul = h->dequant4_coeff[chroma_idx+1+(IS_INTRA( mb_type ) ? 0:3)][h->chroma_qp[chroma_idx]];
1010                 for(i4x4=0; i4x4<4; i4x4++){
1011                     const int index= 16 + 4*chroma_idx + i4x4;
1012                     if( decode_residual(h, gb, h->mb + 16*index, index, scan + 1, qmul, 15) < 0){
1013                         return -1;
1014                     }
1015                 }
1016             }
1017         }else{
1018             uint8_t * const nnz= &h->non_zero_count_cache[0];
1019             nnz[ scan8[16]+0 ] = nnz[ scan8[16]+1 ] =nnz[ scan8[16]+8 ] =nnz[ scan8[16]+9 ] =
1020             nnz[ scan8[20]+0 ] = nnz[ scan8[20]+1 ] =nnz[ scan8[20]+8 ] =nnz[ scan8[20]+9 ] = 0;
1021         }
1022     }else{
1023         uint8_t * const nnz= &h->non_zero_count_cache[0];
1024         fill_rectangle(&nnz[scan8[0]], 4, 4, 8, 0, 1);
1025         nnz[ scan8[16]+0 ] = nnz[ scan8[16]+1 ] =nnz[ scan8[16]+8 ] =nnz[ scan8[16]+9 ] =
1026         nnz[ scan8[20]+0 ] = nnz[ scan8[20]+1 ] =nnz[ scan8[20]+8 ] =nnz[ scan8[20]+9 ] = 0;
1027     }
1028     s->current_picture.qscale_table[mb_xy]= s->qscale;
1029     write_back_non_zero_count(h);
1030
1031     if(MB_MBAFF){
1032         h->ref_count[0] >>= 1;
1033         h->ref_count[1] >>= 1;
1034     }
1035
1036     return 0;
1037 }
1038