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             level_code += ((level_code>>31)|1) & -(trailing_ones < 3);
 445
 446             suffix_length = 1 + (level_code + 3U > 6U);
 447             level[trailing_ones]= level_code;
 448         }
 449
 450         //remaining coefficients have suffix_length > 0
 451         for(i=trailing_ones+1;i<total_coeff;i++) {
 452             static const unsigned int suffix_limit[7] = {0,3,6,12,24,48,INT_MAX };
 453             int bitsi= show_bits(gb, LEVEL_TAB_BITS);
 454             level_code= cavlc_level_tab[suffix_length][bitsi][0];
 455
 456             skip_bits(gb, cavlc_level_tab[suffix_length][bitsi][1]);
 457             if(level_code >= 100){
 458                 prefix= level_code - 100;
 459                 if(prefix == LEVEL_TAB_BITS){
 460                     prefix += get_level_prefix(gb);
 461                 }
 462                 if(prefix<15){
 463                     level_code = (prefix<<suffix_length) + get_bits(gb, suffix_length);
 464                 }else{
 465                     level_code = (15<<suffix_length) + get_bits(gb, prefix-3);
 466                     if(prefix>=16)
 467                         level_code += (1<<(prefix-3))-4096;
 468                 }
 469                 mask= -(level_code&1);
 470                 level_code= (((2+level_code)>>1) ^ mask) - mask;
 471             }
 472             level[i]= level_code;
 473             suffix_length+= suffix_limit[suffix_length] + level_code > 2U*suffix_limit[suffix_length];
 474         }
 475     }
 476
 477     if(total_coeff == max_coeff)
 478         zeros_left=0;
 479     else{
 480         if(n == CHROMA_DC_BLOCK_INDEX)
 481             zeros_left= get_vlc2(gb, (chroma_dc_total_zeros_vlc-1)[ total_coeff ].table, CHROMA_DC_TOTAL_ZEROS_VLC_BITS, 1);
 482         else
 483             zeros_left= get_vlc2(gb, (total_zeros_vlc-1)[ total_coeff ].table, TOTAL_ZEROS_VLC_BITS, 1);
 484     }
 485
 486     coeff_num = zeros_left + total_coeff - 1;
 487     j = scantable[coeff_num];
 488     if(n > 24){
 489         block[j] = level[0];
 490         for(i=1;i<total_coeff;i++) {
 491             if(zeros_left <= 0)
 492                 run_before = 0;
 493             else if(zeros_left < 7){
 494                 run_before= get_vlc2(gb, (run_vlc-1)[zeros_left].table, RUN_VLC_BITS, 1);
 495             }else{
 496                 run_before= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2);
 497             }
 498             zeros_left -= run_before;
 499             coeff_num -= 1 + run_before;
 500             j= scantable[ coeff_num ];
 501
 502             block[j]= level[i];
 503         }
 504     }else{
 505         block[j] = (level[0] * qmul[j] + 32)>>6;
 506         for(i=1;i<total_coeff;i++) {
 507             if(zeros_left <= 0)
 508                 run_before = 0;
 509             else if(zeros_left < 7){
 510                 run_before= get_vlc2(gb, (run_vlc-1)[zeros_left].table, RUN_VLC_BITS, 1);
 511             }else{
 512                 run_before= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2);
 513             }
 514             zeros_left -= run_before;
 515             coeff_num -= 1 + run_before;
 516             j= scantable[ coeff_num ];
 517
 518             block[j]= (level[i] * qmul[j] + 32)>>6;
 519         }
 520     }
 521
 522     if(zeros_left<0){
 523         av_log(h->s.avctx, AV_LOG_ERROR, "negative number of zero coeffs at %d %d\n", s->mb_x, s->mb_y);
 524         return -1;
 525     }
 526
 527     return 0;
 528 }
 529
 530 int ff_h264_decode_mb_cavlc(H264Context *h){
 531     MpegEncContext * const s = &h->s;
 532     int mb_xy;
 533     int partition_count;
 534     unsigned int mb_type, cbp;
 535     int dct8x8_allowed= h->pps.transform_8x8_mode;
 536
 537     mb_xy = h->mb_xy = s->mb_x + s->mb_y*s->mb_stride;
 538
 539     tprintf(s->avctx, "pic:%d mb:%d/%d\n", h->frame_num, s->mb_x, s->mb_y);
 540     cbp = 0; /* avoid warning. FIXME: find a solution without slowing
 541                 down the code */
 542     if(h->slice_type_nos != FF_I_TYPE){
 543         if(s->mb_skip_run==-1)
 544             s->mb_skip_run= get_ue_golomb(&s->gb);
 545
 546         if (s->mb_skip_run--) {
 547             if(FRAME_MBAFF && (s->mb_y&1) == 0){
 548                 if(s->mb_skip_run==0)
 549                     h->mb_mbaff = h->mb_field_decoding_flag = get_bits1(&s->gb);
 550             }
 551             decode_mb_skip(h);
 552             return 0;
 553         }
 554     }
 555     if(FRAME_MBAFF){
 556         if( (s->mb_y&1) == 0 )
 557             h->mb_mbaff = h->mb_field_decoding_flag = get_bits1(&s->gb);
 558     }
 559
 560     h->prev_mb_skipped= 0;
 561
 562     mb_type= get_ue_golomb(&s->gb);
 563     if(h->slice_type_nos == FF_B_TYPE){
 564         if(mb_type < 23){
 565             partition_count= b_mb_type_info[mb_type].partition_count;
 566             mb_type=         b_mb_type_info[mb_type].type;
 567         }else{
 568             mb_type -= 23;
 569             goto decode_intra_mb;
 570         }
 571     }else if(h->slice_type_nos == FF_P_TYPE){
 572         if(mb_type < 5){
 573             partition_count= p_mb_type_info[mb_type].partition_count;
 574             mb_type=         p_mb_type_info[mb_type].type;
 575         }else{
 576             mb_type -= 5;
 577             goto decode_intra_mb;
 578         }
 579     }else{
 580        assert(h->slice_type_nos == FF_I_TYPE);
 581         if(h->slice_type == FF_SI_TYPE && mb_type)
 582             mb_type--;
 583 decode_intra_mb:
 584         if(mb_type > 25){
 585             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);
 586             return -1;
 587         }
 588         partition_count=0;
 589         cbp= i_mb_type_info[mb_type].cbp;
 590         h->intra16x16_pred_mode= i_mb_type_info[mb_type].pred_mode;
 591         mb_type= i_mb_type_info[mb_type].type;
 592     }
 593
 594     if(MB_FIELD)
 595         mb_type |= MB_TYPE_INTERLACED;
 596
 597     h->slice_table[ mb_xy ]= h->slice_num;
 598
 599     if(IS_INTRA_PCM(mb_type)){
 600         unsigned int x;
 601
 602         // We assume these blocks are very rare so we do not optimize it.
 603         align_get_bits(&s->gb);
 604
 605         // The pixels are stored in the same order as levels in h->mb array.
 606         for(x=0; x < (CHROMA ? 384 : 256); x++){
 607             ((uint8_t*)h->mb)[x]= get_bits(&s->gb, 8);
 608         }
 609
 610         // In deblocking, the quantizer is 0
 611         s->current_picture.qscale_table[mb_xy]= 0;
 612         // All coeffs are present
 613         memset(h->non_zero_count[mb_xy], 16, 32);
 614
 615         s->current_picture.mb_type[mb_xy]= mb_type;
 616         return 0;
 617     }
 618
 619     if(MB_MBAFF){
 620         h->ref_count[0] <<= 1;
 621         h->ref_count[1] <<= 1;
 622     }
 623
 624     fill_decode_neighbors(h, mb_type);
 625     fill_decode_caches(h, mb_type);
 626
 627     //mb_pred
 628     if(IS_INTRA(mb_type)){
 629         int pred_mode;
 630 //            init_top_left_availability(h);
 631         if(IS_INTRA4x4(mb_type)){
 632             int i;
 633             int di = 1;
 634             if(dct8x8_allowed && get_bits1(&s->gb)){
 635                 mb_type |= MB_TYPE_8x8DCT;
 636                 di = 4;
 637             }
 638
 639 //                fill_intra4x4_pred_table(h);
 640             for(i=0; i<16; i+=di){
 641                 int mode= pred_intra_mode(h, i);
 642
 643                 if(!get_bits1(&s->gb)){
 644                     const int rem_mode= get_bits(&s->gb, 3);
 645                     mode = rem_mode + (rem_mode >= mode);
 646                 }
 647
 648                 if(di==4)
 649                     fill_rectangle( &h->intra4x4_pred_mode_cache[ scan8[i] ], 2, 2, 8, mode, 1 );
 650                 else
 651                     h->intra4x4_pred_mode_cache[ scan8[i] ] = mode;
 652             }
 653             ff_h264_write_back_intra_pred_mode(h);
 654             if( ff_h264_check_intra4x4_pred_mode(h) < 0)
 655                 return -1;
 656         }else{
 657             h->intra16x16_pred_mode= ff_h264_check_intra_pred_mode(h, h->intra16x16_pred_mode);
 658             if(h->intra16x16_pred_mode < 0)
 659                 return -1;
 660         }
 661         if(CHROMA){
 662             pred_mode= ff_h264_check_intra_pred_mode(h, get_ue_golomb_31(&s->gb));
 663             if(pred_mode < 0)
 664                 return -1;
 665             h->chroma_pred_mode= pred_mode;
 666         }
 667     }else if(partition_count==4){
 668         int i, j, sub_partition_count[4], list, ref[2][4];
 669
 670         if(h->slice_type_nos == FF_B_TYPE){
 671             for(i=0; i<4; i++){
 672                 h->sub_mb_type[i]= get_ue_golomb_31(&s->gb);
 673                 if(h->sub_mb_type[i] >=13){
 674                     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);
 675                     return -1;
 676                 }
 677                 sub_partition_count[i]= b_sub_mb_type_info[ h->sub_mb_type[i] ].partition_count;
 678                 h->sub_mb_type[i]=      b_sub_mb_type_info[ h->sub_mb_type[i] ].type;
 679             }
 680             if( IS_DIRECT(h->sub_mb_type[0]|h->sub_mb_type[1]|h->sub_mb_type[2]|h->sub_mb_type[3])) {
 681                 ff_h264_pred_direct_motion(h, &mb_type);
 682                 h->ref_cache[0][scan8[4]] =
 683                 h->ref_cache[1][scan8[4]] =
 684                 h->ref_cache[0][scan8[12]] =
 685                 h->ref_cache[1][scan8[12]] = PART_NOT_AVAILABLE;
 686             }
 687         }else{
 688             assert(h->slice_type_nos == FF_P_TYPE); //FIXME SP correct ?
 689             for(i=0; i<4; i++){
 690                 h->sub_mb_type[i]= get_ue_golomb_31(&s->gb);
 691                 if(h->sub_mb_type[i] >=4){
 692                     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);
 693                     return -1;
 694                 }
 695                 sub_partition_count[i]= p_sub_mb_type_info[ h->sub_mb_type[i] ].partition_count;
 696                 h->sub_mb_type[i]=      p_sub_mb_type_info[ h->sub_mb_type[i] ].type;
 697             }
 698         }
 699
 700         for(list=0; list<h->list_count; list++){
 701             int ref_count= IS_REF0(mb_type) ? 1 : h->ref_count[list];
 702             for(i=0; i<4; i++){
 703                 if(IS_DIRECT(h->sub_mb_type[i])) continue;
 704                 if(IS_DIR(h->sub_mb_type[i], 0, list)){
 705                     unsigned int tmp;
 706                     if(ref_count == 1){
 707                         tmp= 0;
 708                     }else if(ref_count == 2){
 709                         tmp= get_bits1(&s->gb)^1;
 710                     }else{
 711                         tmp= get_ue_golomb_31(&s->gb);
 712                         if(tmp>=ref_count){
 713                             av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", tmp);
 714                             return -1;
 715                         }
 716                     }
 717                     ref[list][i]= tmp;
 718                 }else{
 719                  //FIXME
 720                     ref[list][i] = -1;
 721                 }
 722             }
 723         }
 724
 725         if(dct8x8_allowed)
 726             dct8x8_allowed = get_dct8x8_allowed(h);
 727
 728         for(list=0; list<h->list_count; list++){
 729             for(i=0; i<4; i++){
 730                 if(IS_DIRECT(h->sub_mb_type[i])) {
 731                     h->ref_cache[list][ scan8[4*i] ] = h->ref_cache[list][ scan8[4*i]+1 ];
 732                     continue;
 733                 }
 734                 h->ref_cache[list][ scan8[4*i]   ]=h->ref_cache[list][ scan8[4*i]+1 ]=
 735                 h->ref_cache[list][ scan8[4*i]+8 ]=h->ref_cache[list][ scan8[4*i]+9 ]= ref[list][i];
 736
 737                 if(IS_DIR(h->sub_mb_type[i], 0, list)){
 738                     const int sub_mb_type= h->sub_mb_type[i];
 739                     const int block_width= (sub_mb_type & (MB_TYPE_16x16|MB_TYPE_16x8)) ? 2 : 1;
 740                     for(j=0; j<sub_partition_count[i]; j++){
 741                         int mx, my;
 742                         const int index= 4*i + block_width*j;
 743                         int16_t (* mv_cache)[2]= &h->mv_cache[list][ scan8[index] ];
 744                         pred_motion(h, index, block_width, list, h->ref_cache[list][ scan8[index] ], &mx, &my);
 745                         mx += get_se_golomb(&s->gb);
 746                         my += get_se_golomb(&s->gb);
 747                         tprintf(s->avctx, "final mv:%d %d\n", mx, my);
 748
 749                         if(IS_SUB_8X8(sub_mb_type)){
 750                             mv_cache[ 1 ][0]=
 751                             mv_cache[ 8 ][0]= mv_cache[ 9 ][0]= mx;
 752                             mv_cache[ 1 ][1]=
 753                             mv_cache[ 8 ][1]= mv_cache[ 9 ][1]= my;
 754                         }else if(IS_SUB_8X4(sub_mb_type)){
 755                             mv_cache[ 1 ][0]= mx;
 756                             mv_cache[ 1 ][1]= my;
 757                         }else if(IS_SUB_4X8(sub_mb_type)){
 758                             mv_cache[ 8 ][0]= mx;
 759                             mv_cache[ 8 ][1]= my;
 760                         }
 761                         mv_cache[ 0 ][0]= mx;
 762                         mv_cache[ 0 ][1]= my;
 763                     }
 764                 }else{
 765                     uint32_t *p= (uint32_t *)&h->mv_cache[list][ scan8[4*i] ][0];
 766                     p[0] = p[1]=
 767                     p[8] = p[9]= 0;
 768                 }
 769             }
 770         }
 771     }else if(IS_DIRECT(mb_type)){
 772         ff_h264_pred_direct_motion(h, &mb_type);
 773         dct8x8_allowed &= h->sps.direct_8x8_inference_flag;
 774     }else{
 775         int list, mx, my, i;
 776          //FIXME we should set ref_idx_l? to 0 if we use that later ...
 777         if(IS_16X16(mb_type)){
 778             for(list=0; list<h->list_count; list++){
 779                     unsigned int val;
 780                     if(IS_DIR(mb_type, 0, list)){
 781                         if(h->ref_count[list]==1){
 782                             val= 0;
 783                         }else if(h->ref_count[list]==2){
 784                             val= get_bits1(&s->gb)^1;
 785                         }else{
 786                             val= get_ue_golomb_31(&s->gb);
 787                             if(val >= h->ref_count[list]){
 788                                 av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);
 789                                 return -1;
 790                             }
 791                         }
 792                     }else
 793                         val= LIST_NOT_USED&0xFF;
 794                     fill_rectangle(&h->ref_cache[list][ scan8[0] ], 4, 4, 8, val, 1);
 795             }
 796             for(list=0; list<h->list_count; list++){
 797                 unsigned int val;
 798                 if(IS_DIR(mb_type, 0, list)){
 799                     pred_motion(h, 0, 4, list, h->ref_cache[list][ scan8[0] ], &mx, &my);
 800                     mx += get_se_golomb(&s->gb);
 801                     my += get_se_golomb(&s->gb);
 802                     tprintf(s->avctx, "final mv:%d %d\n", mx, my);
 803
 804                     val= pack16to32(mx,my);
 805                 }else
 806                     val=0;
 807                 fill_rectangle(h->mv_cache[list][ scan8[0] ], 4, 4, 8, val, 4);
 808             }
 809         }
 810         else if(IS_16X8(mb_type)){
 811             for(list=0; list<h->list_count; list++){
 812                     for(i=0; i<2; i++){
 813                         unsigned int val;
 814                         if(IS_DIR(mb_type, i, list)){
 815                             if(h->ref_count[list] == 1){
 816                                 val= 0;
 817                             }else if(h->ref_count[list] == 2){
 818                                 val= get_bits1(&s->gb)^1;
 819                             }else{
 820                                 val= get_ue_golomb_31(&s->gb);
 821                                 if(val >= h->ref_count[list]){
 822                                     av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);
 823                                     return -1;
 824                                 }
 825                             }
 826                         }else
 827                             val= LIST_NOT_USED&0xFF;
 828                         fill_rectangle(&h->ref_cache[list][ scan8[0] + 16*i ], 4, 2, 8, val, 1);
 829                     }
 830             }
 831             for(list=0; list<h->list_count; list++){
 832                 for(i=0; i<2; i++){
 833                     unsigned int val;
 834                     if(IS_DIR(mb_type, i, list)){
 835                         pred_16x8_motion(h, 8*i, list, h->ref_cache[list][scan8[0] + 16*i], &mx, &my);
 836                         mx += get_se_golomb(&s->gb);
 837                         my += get_se_golomb(&s->gb);
 838                         tprintf(s->avctx, "final mv:%d %d\n", mx, my);
 839
 840                         val= pack16to32(mx,my);
 841                     }else
 842                         val=0;
 843                     fill_rectangle(h->mv_cache[list][ scan8[0] + 16*i ], 4, 2, 8, val, 4);
 844                 }
 845             }
 846         }else{
 847             assert(IS_8X16(mb_type));
 848             for(list=0; list<h->list_count; list++){
 849                     for(i=0; i<2; i++){
 850                         unsigned int val;
 851                         if(IS_DIR(mb_type, i, list)){ //FIXME optimize
 852                             if(h->ref_count[list]==1){
 853                                 val= 0;
 854                             }else if(h->ref_count[list]==2){
 855                                 val= get_bits1(&s->gb)^1;
 856                             }else{
 857                                 val= get_ue_golomb_31(&s->gb);
 858                                 if(val >= h->ref_count[list]){
 859                                     av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);
 860                                     return -1;
 861                                 }
 862                             }
 863                         }else
 864                             val= LIST_NOT_USED&0xFF;
 865                         fill_rectangle(&h->ref_cache[list][ scan8[0] + 2*i ], 2, 4, 8, val, 1);
 866                     }
 867             }
 868             for(list=0; list<h->list_count; list++){
 869                 for(i=0; i<2; i++){
 870                     unsigned int val;
 871                     if(IS_DIR(mb_type, i, list)){
 872                         pred_8x16_motion(h, i*4, list, h->ref_cache[list][ scan8[0] + 2*i ], &mx, &my);
 873                         mx += get_se_golomb(&s->gb);
 874                         my += get_se_golomb(&s->gb);
 875                         tprintf(s->avctx, "final mv:%d %d\n", mx, my);
 876
 877                         val= pack16to32(mx,my);
 878                     }else
 879                         val=0;
 880                     fill_rectangle(h->mv_cache[list][ scan8[0] + 2*i ], 2, 4, 8, val, 4);
 881                 }
 882             }
 883         }
 884     }
 885
 886     if(IS_INTER(mb_type))
 887         write_back_motion(h, mb_type);
 888
 889     if(!IS_INTRA16x16(mb_type)){
 890         cbp= get_ue_golomb(&s->gb);
 891         if(cbp > 47){
 892             av_log(h->s.avctx, AV_LOG_ERROR, "cbp too large (%u) at %d %d\n", cbp, s->mb_x, s->mb_y);
 893             return -1;
 894         }
 895
 896         if(CHROMA){
 897             if(IS_INTRA4x4(mb_type)) cbp= golomb_to_intra4x4_cbp[cbp];
 898             else                     cbp= golomb_to_inter_cbp   [cbp];
 899         }else{
 900             if(IS_INTRA4x4(mb_type)) cbp= golomb_to_intra4x4_cbp_gray[cbp];
 901             else                     cbp= golomb_to_inter_cbp_gray[cbp];
 902         }
 903     }
 904
 905     if(dct8x8_allowed && (cbp&15) && !IS_INTRA(mb_type)){
 906         mb_type |= MB_TYPE_8x8DCT*get_bits1(&s->gb);
 907     }
 908     h->cbp=
 909     h->cbp_table[mb_xy]= cbp;
 910     s->current_picture.mb_type[mb_xy]= mb_type;
 911
 912     if(cbp || IS_INTRA16x16(mb_type)){
 913         int i8x8, i4x4, chroma_idx;
 914         int dquant;
 915         GetBitContext *gb= IS_INTRA(mb_type) ? h->intra_gb_ptr : h->inter_gb_ptr;
 916         const uint8_t *scan, *scan8x8, *dc_scan;
 917
 918         if(IS_INTERLACED(mb_type)){
 919             scan8x8= s->qscale ? h->field_scan8x8_cavlc : h->field_scan8x8_cavlc_q0;
 920             scan= s->qscale ? h->field_scan : h->field_scan_q0;
 921             dc_scan= luma_dc_field_scan;
 922         }else{
 923             scan8x8= s->qscale ? h->zigzag_scan8x8_cavlc : h->zigzag_scan8x8_cavlc_q0;
 924             scan= s->qscale ? h->zigzag_scan : h->zigzag_scan_q0;
 925             dc_scan= luma_dc_zigzag_scan;
 926         }
 927
 928         dquant= get_se_golomb(&s->gb);
 929
 930         s->qscale += dquant;
 931
 932         if(((unsigned)s->qscale) > 51){
 933             if(s->qscale<0) s->qscale+= 52;
 934             else            s->qscale-= 52;
 935             if(((unsigned)s->qscale) > 51){
 936                 av_log(h->s.avctx, AV_LOG_ERROR, "dquant out of range (%d) at %d %d\n", dquant, s->mb_x, s->mb_y);
 937                 return -1;
 938             }
 939         }
 940
 941         h->chroma_qp[0]= get_chroma_qp(h, 0, s->qscale);
 942         h->chroma_qp[1]= get_chroma_qp(h, 1, s->qscale);
 943         if(IS_INTRA16x16(mb_type)){
 944             if( decode_residual(h, h->intra_gb_ptr, h->mb, LUMA_DC_BLOCK_INDEX, dc_scan, h->dequant4_coeff[0][s->qscale], 16) < 0){
 945                 return -1; //FIXME continue if partitioned and other return -1 too
 946             }
 947
 948             assert((cbp&15) == 0 || (cbp&15) == 15);
 949
 950             if(cbp&15){
 951                 for(i8x8=0; i8x8<4; i8x8++){
 952                     for(i4x4=0; i4x4<4; i4x4++){
 953                         const int index= i4x4 + 4*i8x8;
 954                         if( decode_residual(h, h->intra_gb_ptr, h->mb + 16*index, index, scan + 1, h->dequant4_coeff[0][s->qscale], 15) < 0 ){
 955                             return -1;
 956                         }
 957                     }
 958                 }
 959             }else{
 960                 fill_rectangle(&h->non_zero_count_cache[scan8[0]], 4, 4, 8, 0, 1);
 961             }
 962         }else{
 963             for(i8x8=0; i8x8<4; i8x8++){
 964                 if(cbp & (1<<i8x8)){
 965                     if(IS_8x8DCT(mb_type)){
 966                         DCTELEM *buf = &h->mb[64*i8x8];
 967                         uint8_t *nnz;
 968                         for(i4x4=0; i4x4<4; i4x4++){
 969                             if( decode_residual(h, gb, buf, i4x4+4*i8x8, scan8x8+16*i4x4,
 970                                                 h->dequant8_coeff[IS_INTRA( mb_type ) ? 0:1][s->qscale], 16) <0 )
 971                                 return -1;
 972                         }
 973                         nnz= &h->non_zero_count_cache[ scan8[4*i8x8] ];
 974                         nnz[0] += nnz[1] + nnz[8] + nnz[9];
 975                     }else{
 976                         for(i4x4=0; i4x4<4; i4x4++){
 977                             const int index= i4x4 + 4*i8x8;
 978
 979                             if( decode_residual(h, gb, h->mb + 16*index, index, scan, h->dequant4_coeff[IS_INTRA( mb_type ) ? 0:3][s->qscale], 16) <0 ){
 980                                 return -1;
 981                             }
 982                         }
 983                     }
 984                 }else{
 985                     uint8_t * const nnz= &h->non_zero_count_cache[ scan8[4*i8x8] ];
 986                     nnz[0] = nnz[1] = nnz[8] = nnz[9] = 0;
 987                 }
 988             }
 989         }
 990
 991         if(cbp&0x30){
 992             for(chroma_idx=0; chroma_idx<2; chroma_idx++)
 993                 if( decode_residual(h, gb, h->mb + 256 + 16*4*chroma_idx, CHROMA_DC_BLOCK_INDEX, chroma_dc_scan, NULL, 4) < 0){
 994                     return -1;
 995                 }
 996         }
 997
 998         if(cbp&0x20){
 999             for(chroma_idx=0; chroma_idx<2; chroma_idx++){
1000                 const uint32_t *qmul = h->dequant4_coeff[chroma_idx+1+(IS_INTRA( mb_type ) ? 0:3)][h->chroma_qp[chroma_idx]];
1001                 for(i4x4=0; i4x4<4; i4x4++){
1002                     const int index= 16 + 4*chroma_idx + i4x4;
1003                     if( decode_residual(h, gb, h->mb + 16*index, index, scan + 1, qmul, 15) < 0){
1004                         return -1;
1005                     }
1006                 }
1007             }
1008         }else{
1009             uint8_t * const nnz= &h->non_zero_count_cache[0];
1010             nnz[ scan8[16]+0 ] = nnz[ scan8[16]+1 ] =nnz[ scan8[16]+8 ] =nnz[ scan8[16]+9 ] =
1011             nnz[ scan8[20]+0 ] = nnz[ scan8[20]+1 ] =nnz[ scan8[20]+8 ] =nnz[ scan8[20]+9 ] = 0;
1012         }
1013     }else{
1014         uint8_t * const nnz= &h->non_zero_count_cache[0];
1015         fill_rectangle(&nnz[scan8[0]], 4, 4, 8, 0, 1);
1016         nnz[ scan8[16]+0 ] = nnz[ scan8[16]+1 ] =nnz[ scan8[16]+8 ] =nnz[ scan8[16]+9 ] =
1017         nnz[ scan8[20]+0 ] = nnz[ scan8[20]+1 ] =nnz[ scan8[20]+8 ] =nnz[ scan8[20]+9 ] = 0;
1018     }
1019     s->current_picture.qscale_table[mb_xy]= s->qscale;
1020     write_back_non_zero_count(h);
1021
1022     if(MB_MBAFF){
1023         h->ref_count[0] >>= 1;
1024         h->ref_count[1] >>= 1;
1025     }
1026
1027     return 0;
1028 }
1029