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FFmpeg/libavcodec/h264_cavlc.c

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  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

  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_token, total_coeff, i, 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.                     if(prefix > 25+3){

  436.                         av_log(h->s.avctx, AV_LOG_ERROR, "Invalid level prefix\n");

  437.                         return -1;

  438.                     }

  439.                     level_code += (1<<(prefix-3))-4096;

  440.                 }

  441.             }

  442. 

  443.             if(trailing_ones < 3) level_code += 2;

  444. 

  445.             suffix_length = 2;

  446.             mask= -(level_code&1);

  447.             level[trailing_ones]= (((2+level_code)>>1) ^ mask) - mask;

  448.         }else{

  449.             level_code += ((level_code>>31)|1) & -(trailing_ones < 3);

  450. 

  451.             suffix_length = 1 + (level_code + 3U > 6U);

  452.             level[trailing_ones]= level_code;

  453.         }

  454. 

  455.         //remaining coefficients have suffix_length > 0

  456.         for(i=trailing_ones+1;i<total_coeff;i++) {

  457.             static const unsigned int suffix_limit[7] = {0,3,6,12,24,48,INT_MAX };

  458.             int bitsi= show_bits(gb, LEVEL_TAB_BITS);

  459.             level_code= cavlc_level_tab[suffix_length][bitsi][0];

  460. 

  461.             skip_bits(gb, cavlc_level_tab[suffix_length][bitsi][1]);

  462.             if(level_code >= 100){

  463.                 prefix= level_code - 100;

  464.                 if(prefix == LEVEL_TAB_BITS){

  465.                     prefix += get_level_prefix(gb);

  466.                 }

  467.                 if(prefix<15){

  468.                     level_code = (prefix<<suffix_length) + get_bits(gb, suffix_length);

  469.                 }else{

  470.                     level_code = (15<<suffix_length) + get_bits(gb, prefix-3);

  471.                     if(prefix>=16)

  472.                         level_code += (1<<(prefix-3))-4096;

  473.                 }

  474.                 mask= -(level_code&1);

  475.                 level_code= (((2+level_code)>>1) ^ mask) - mask;

  476.             }

  477.             level[i]= level_code;

  478.             suffix_length+= suffix_limit[suffix_length] + level_code > 2U*suffix_limit[suffix_length];

  479.         }

  480.     }

  481. 

  482.     if(total_coeff == max_coeff)

  483.         zeros_left=0;

  484.     else{

  485.         if(n == CHROMA_DC_BLOCK_INDEX)

  486.             zeros_left= get_vlc2(gb, (chroma_dc_total_zeros_vlc-1)[ total_coeff ].table, CHROMA_DC_TOTAL_ZEROS_VLC_BITS, 1);

  487.         else

  488.             zeros_left= get_vlc2(gb, (total_zeros_vlc-1)[ total_coeff ].table, TOTAL_ZEROS_VLC_BITS, 1);

  489.     }

  490. 

  491.     scantable += zeros_left + total_coeff - 1;

  492.     if(n > 24){

  493.         block[*scantable] = level[0];

  494.         for(i=1;i<total_coeff && zeros_left > 0;i++) {

  495.             if(zeros_left < 7)

  496.                 run_before= get_vlc2(gb, (run_vlc-1)[zeros_left].table, RUN_VLC_BITS, 1);

  497.             else

  498.                 run_before= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2);

  499.             zeros_left -= run_before;

  500.             scantable -= 1 + run_before;

  501.             block[*scantable]= level[i];

  502.         }

  503.         for(;i<total_coeff;i++) {

  504.             scantable--;

  505.             block[*scantable]= level[i];

  506.         }

  507.     }else{

  508.         block[*scantable] = (level[0] * qmul[*scantable] + 32)>>6;

  509.         for(i=1;i<total_coeff && zeros_left > 0;i++) {

  510.             if(zeros_left < 7)

  511.                 run_before= get_vlc2(gb, (run_vlc-1)[zeros_left].table, RUN_VLC_BITS, 1);

  512.             else

  513.                 run_before= get_vlc2(gb, run7_vlc.table, RUN7_VLC_BITS, 2);

  514.             zeros_left -= run_before;

  515.             scantable -= 1 + run_before;

  516.             block[*scantable]= (level[i] * qmul[*scantable] + 32)>>6;

  517.         }

  518.         for(;i<total_coeff;i++) {

  519.             scantable--;

  520.             block[*scantable]= (level[i] * qmul[*scantable] + 32)>>6;

  521.         }

  522.     }

  523. 

  524.     if(zeros_left<0){

  525.         av_log(h->s.avctx, AV_LOG_ERROR, "negative number of zero coeffs at %d %d\n", s->mb_x, s->mb_y);

  526.         return -1;

  527.     }

  528. 

  529.     return 0;

  530. }

  531. 

  532. int ff_h264_decode_mb_cavlc(H264Context *h){

  533.     MpegEncContext * const s = &h->s;

  534.     int mb_xy;

  535.     int partition_count;

  536.     unsigned int mb_type, cbp;

  537.     int dct8x8_allowed= h->pps.transform_8x8_mode;

  538. 

  539.     mb_xy = h->mb_xy = s->mb_x + s->mb_y*s->mb_stride;

  540. 

  541.     tprintf(s->avctx, "pic:%d mb:%d/%d\n", h->frame_num, s->mb_x, s->mb_y);

  542.     cbp = 0; /* avoid warning. FIXME: find a solution without slowing

  543.                 down the code */

  544.     if(h->slice_type_nos != FF_I_TYPE){

  545.         if(s->mb_skip_run==-1)

  546.             s->mb_skip_run= get_ue_golomb(&s->gb);

  547. 

  548.         if (s->mb_skip_run--) {

  549.             if(FRAME_MBAFF && (s->mb_y&1) == 0){

  550.                 if(s->mb_skip_run==0)

  551.                     h->mb_mbaff = h->mb_field_decoding_flag = get_bits1(&s->gb);

  552.             }

  553.             decode_mb_skip(h);

  554.             return 0;

  555.         }

  556.     }

  557.     if(FRAME_MBAFF){

  558.         if( (s->mb_y&1) == 0 )

  559.             h->mb_mbaff = h->mb_field_decoding_flag = get_bits1(&s->gb);

  560.     }

  561. 

  562.     h->prev_mb_skipped= 0;

  563. 

  564.     mb_type= get_ue_golomb(&s->gb);

  565.     if(h->slice_type_nos == FF_B_TYPE){

  566.         if(mb_type < 23){

  567.             partition_count= b_mb_type_info[mb_type].partition_count;

  568.             mb_type=         b_mb_type_info[mb_type].type;

  569.         }else{

  570.             mb_type -= 23;

  571.             goto decode_intra_mb;

  572.         }

  573.     }else if(h->slice_type_nos == FF_P_TYPE){

  574.         if(mb_type < 5){

  575.             partition_count= p_mb_type_info[mb_type].partition_count;

  576.             mb_type=         p_mb_type_info[mb_type].type;

  577.         }else{

  578.             mb_type -= 5;

  579.             goto decode_intra_mb;

  580.         }

  581.     }else{

  582.        assert(h->slice_type_nos == FF_I_TYPE);

  583.         if(h->slice_type == FF_SI_TYPE && mb_type)

  584.             mb_type--;

  585. decode_intra_mb:

  586.         if(mb_type > 25){

  587.             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);

  588.             return -1;

  589.         }

  590.         partition_count=0;

  591.         cbp= i_mb_type_info[mb_type].cbp;

  592.         h->intra16x16_pred_mode= i_mb_type_info[mb_type].pred_mode;

  593.         mb_type= i_mb_type_info[mb_type].type;

  594.     }

  595. 

  596.     if(MB_FIELD)

  597.         mb_type |= MB_TYPE_INTERLACED;

  598. 

  599.     h->slice_table[ mb_xy ]= h->slice_num;

  600. 

  601.     if(IS_INTRA_PCM(mb_type)){

  602.         unsigned int x;

  603. 

  604.         // We assume these blocks are very rare so we do not optimize it.

  605.         align_get_bits(&s->gb);

  606. 

  607.         // The pixels are stored in the same order as levels in h->mb array.

  608.         for(x=0; x < (CHROMA ? 384 : 256); x++){

  609.             ((uint8_t*)h->mb)[x]= get_bits(&s->gb, 8);

  610.         }

  611. 

  612.         // In deblocking, the quantizer is 0

  613.         s->current_picture.qscale_table[mb_xy]= 0;

  614.         // All coeffs are present

  615.         memset(h->non_zero_count[mb_xy], 16, 32);

  616. 

  617.         s->current_picture.mb_type[mb_xy]= mb_type;

  618.         return 0;

  619.     }

  620. 

  621.     if(MB_MBAFF){

  622.         h->ref_count[0] <<= 1;

  623.         h->ref_count[1] <<= 1;

  624.     }

  625. 

  626.     fill_decode_neighbors(h, mb_type);

  627.     fill_decode_caches(h, mb_type);

  628. 

  629.     //mb_pred

  630.     if(IS_INTRA(mb_type)){

  631.         int pred_mode;

  632. //            init_top_left_availability(h);

  633.         if(IS_INTRA4x4(mb_type)){

  634.             int i;

  635.             int di = 1;

  636.             if(dct8x8_allowed && get_bits1(&s->gb)){

  637.                 mb_type |= MB_TYPE_8x8DCT;

  638.                 di = 4;

  639.             }

  640. 

  641. //                fill_intra4x4_pred_table(h);

  642.             for(i=0; i<16; i+=di){

  643.                 int mode= pred_intra_mode(h, i);

  644. 

  645.                 if(!get_bits1(&s->gb)){

  646.                     const int rem_mode= get_bits(&s->gb, 3);

  647.                     mode = rem_mode + (rem_mode >= mode);

  648.                 }

  649. 

  650.                 if(di==4)

  651.                     fill_rectangle( &h->intra4x4_pred_mode_cache[ scan8[i] ], 2, 2, 8, mode, 1 );

  652.                 else

  653.                     h->intra4x4_pred_mode_cache[ scan8[i] ] = mode;

  654.             }

  655.             ff_h264_write_back_intra_pred_mode(h);

  656.             if( ff_h264_check_intra4x4_pred_mode(h) < 0)

  657.                 return -1;

  658.         }else{

  659.             h->intra16x16_pred_mode= ff_h264_check_intra_pred_mode(h, h->intra16x16_pred_mode);

  660.             if(h->intra16x16_pred_mode < 0)

  661.                 return -1;

  662.         }

  663.         if(CHROMA){

  664.             pred_mode= ff_h264_check_intra_pred_mode(h, get_ue_golomb_31(&s->gb));

  665.             if(pred_mode < 0)

  666.                 return -1;

  667.             h->chroma_pred_mode= pred_mode;

  668.         }

  669.     }else if(partition_count==4){

  670.         int i, j, sub_partition_count[4], list, ref[2][4];

  671. 

  672.         if(h->slice_type_nos == FF_B_TYPE){

  673.             for(i=0; i<4; i++){

  674.                 h->sub_mb_type[i]= get_ue_golomb_31(&s->gb);

  675.                 if(h->sub_mb_type[i] >=13){

  676.                     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);

  677.                     return -1;

  678.                 }

  679.                 sub_partition_count[i]= b_sub_mb_type_info[ h->sub_mb_type[i] ].partition_count;

  680.                 h->sub_mb_type[i]=      b_sub_mb_type_info[ h->sub_mb_type[i] ].type;

  681.             }

  682.             if( IS_DIRECT(h->sub_mb_type[0]|h->sub_mb_type[1]|h->sub_mb_type[2]|h->sub_mb_type[3])) {

  683.                 ff_h264_pred_direct_motion(h, &mb_type);

  684.                 h->ref_cache[0][scan8[4]] =

  685.                 h->ref_cache[1][scan8[4]] =

  686.                 h->ref_cache[0][scan8[12]] =

  687.                 h->ref_cache[1][scan8[12]] = PART_NOT_AVAILABLE;

  688.             }

  689.         }else{

  690.             assert(h->slice_type_nos == FF_P_TYPE); //FIXME SP correct ?

  691.             for(i=0; i<4; i++){

  692.                 h->sub_mb_type[i]= get_ue_golomb_31(&s->gb);

  693.                 if(h->sub_mb_type[i] >=4){

  694.                     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);

  695.                     return -1;

  696.                 }

  697.                 sub_partition_count[i]= p_sub_mb_type_info[ h->sub_mb_type[i] ].partition_count;

  698.                 h->sub_mb_type[i]=      p_sub_mb_type_info[ h->sub_mb_type[i] ].type;

  699.             }

  700.         }

  701. 

  702.         for(list=0; list<h->list_count; list++){

  703.             int ref_count= IS_REF0(mb_type) ? 1 : h->ref_count[list];

  704.             for(i=0; i<4; i++){

  705.                 if(IS_DIRECT(h->sub_mb_type[i])) continue;

  706.                 if(IS_DIR(h->sub_mb_type[i], 0, list)){

  707.                     unsigned int tmp;

  708.                     if(ref_count == 1){

  709.                         tmp= 0;

  710.                     }else if(ref_count == 2){

  711.                         tmp= get_bits1(&s->gb)^1;

  712.                     }else{

  713.                         tmp= get_ue_golomb_31(&s->gb);

  714.                         if(tmp>=ref_count){

  715.                             av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", tmp);

  716.                             return -1;

  717.                         }

  718.                     }

  719.                     ref[list][i]= tmp;

  720.                 }else{

  721.                  //FIXME

  722.                     ref[list][i] = -1;

  723.                 }

  724.             }

  725.         }

  726. 

  727.         if(dct8x8_allowed)

  728.             dct8x8_allowed = get_dct8x8_allowed(h);

  729. 

  730.         for(list=0; list<h->list_count; list++){

  731.             for(i=0; i<4; i++){

  732.                 if(IS_DIRECT(h->sub_mb_type[i])) {

  733.                     h->ref_cache[list][ scan8[4*i] ] = h->ref_cache[list][ scan8[4*i]+1 ];

  734.                     continue;

  735.                 }

  736.                 h->ref_cache[list][ scan8[4*i]   ]=h->ref_cache[list][ scan8[4*i]+1 ]=

  737.                 h->ref_cache[list][ scan8[4*i]+8 ]=h->ref_cache[list][ scan8[4*i]+9 ]= ref[list][i];

  738. 

  739.                 if(IS_DIR(h->sub_mb_type[i], 0, list)){

  740.                     const int sub_mb_type= h->sub_mb_type[i];

  741.                     const int block_width= (sub_mb_type & (MB_TYPE_16x16|MB_TYPE_16x8)) ? 2 : 1;

  742.                     for(j=0; j<sub_partition_count[i]; j++){

  743.                         int mx, my;

  744.                         const int index= 4*i + block_width*j;

  745.                         int16_t (* mv_cache)[2]= &h->mv_cache[list][ scan8[index] ];

  746.                         pred_motion(h, index, block_width, list, h->ref_cache[list][ scan8[index] ], &mx, &my);

  747.                         mx += get_se_golomb(&s->gb);

  748.                         my += get_se_golomb(&s->gb);

  749.                         tprintf(s->avctx, "final mv:%d %d\n", mx, my);

  750. 

  751.                         if(IS_SUB_8X8(sub_mb_type)){

  752.                             mv_cache[ 1 ][0]=

  753.                             mv_cache[ 8 ][0]= mv_cache[ 9 ][0]= mx;

  754.                             mv_cache[ 1 ][1]=

  755.                             mv_cache[ 8 ][1]= mv_cache[ 9 ][1]= my;

  756.                         }else if(IS_SUB_8X4(sub_mb_type)){

  757.                             mv_cache[ 1 ][0]= mx;

  758.                             mv_cache[ 1 ][1]= my;

  759.                         }else if(IS_SUB_4X8(sub_mb_type)){

  760.                             mv_cache[ 8 ][0]= mx;

  761.                             mv_cache[ 8 ][1]= my;

  762.                         }

  763.                         mv_cache[ 0 ][0]= mx;

  764.                         mv_cache[ 0 ][1]= my;

  765.                     }

  766.                 }else{

  767.                     uint32_t *p= (uint32_t *)&h->mv_cache[list][ scan8[4*i] ][0];

  768.                     p[0] = p[1]=

  769.                     p[8] = p[9]= 0;

  770.                 }

  771.             }

  772.         }

  773.     }else if(IS_DIRECT(mb_type)){

  774.         ff_h264_pred_direct_motion(h, &mb_type);

  775.         dct8x8_allowed &= h->sps.direct_8x8_inference_flag;

  776.     }else{

  777.         int list, mx, my, i;

  778.          //FIXME we should set ref_idx_l? to 0 if we use that later ...

  779.         if(IS_16X16(mb_type)){

  780.             for(list=0; list<h->list_count; list++){

  781.                     unsigned int val;

  782.                     if(IS_DIR(mb_type, 0, list)){

  783.                         if(h->ref_count[list]==1){

  784.                             val= 0;

  785.                         }else if(h->ref_count[list]==2){

  786.                             val= get_bits1(&s->gb)^1;

  787.                         }else{

  788.                             val= get_ue_golomb_31(&s->gb);

  789.                             if(val >= h->ref_count[list]){

  790.                                 av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);

  791.                                 return -1;

  792.                             }

  793.                         }

  794.                     fill_rectangle(&h->ref_cache[list][ scan8[0] ], 4, 4, 8, val, 1);

  795.                     }

  796.             }

  797.             for(list=0; list<h->list_count; list++){

  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.                     fill_rectangle(h->mv_cache[list][ scan8[0] ], 4, 4, 8, pack16to32(mx,my), 4);

  805.                 }

  806.             }

  807.         }

  808.         else if(IS_16X8(mb_type)){

  809.             for(list=0; list<h->list_count; list++){

  810.                     for(i=0; i<2; i++){

  811.                         unsigned int val;

  812.                         if(IS_DIR(mb_type, i, list)){

  813.                             if(h->ref_count[list] == 1){

  814.                                 val= 0;

  815.                             }else if(h->ref_count[list] == 2){

  816.                                 val= get_bits1(&s->gb)^1;

  817.                             }else{

  818.                                 val= get_ue_golomb_31(&s->gb);

  819.                                 if(val >= h->ref_count[list]){

  820.                                     av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);

  821.                                     return -1;

  822.                                 }

  823.                             }

  824.                         }else

  825.                             val= LIST_NOT_USED&0xFF;

  826.                         fill_rectangle(&h->ref_cache[list][ scan8[0] + 16*i ], 4, 2, 8, val, 1);

  827.                     }

  828.             }

  829.             for(list=0; list<h->list_count; list++){

  830.                 for(i=0; i<2; i++){

  831.                     unsigned int val;

  832.                     if(IS_DIR(mb_type, i, list)){

  833.                         pred_16x8_motion(h, 8*i, list, h->ref_cache[list][scan8[0] + 16*i], &mx, &my);

  834.                         mx += get_se_golomb(&s->gb);

  835.                         my += get_se_golomb(&s->gb);

  836.                         tprintf(s->avctx, "final mv:%d %d\n", mx, my);

  837. 

  838.                         val= pack16to32(mx,my);

  839.                     }else

  840.                         val=0;

  841.                     fill_rectangle(h->mv_cache[list][ scan8[0] + 16*i ], 4, 2, 8, val, 4);

  842.                 }

  843.             }

  844.         }else{

  845.             assert(IS_8X16(mb_type));

  846.             for(list=0; list<h->list_count; list++){

  847.                     for(i=0; i<2; i++){

  848.                         unsigned int val;

  849.                         if(IS_DIR(mb_type, i, list)){ //FIXME optimize

  850.                             if(h->ref_count[list]==1){

  851.                                 val= 0;

  852.                             }else if(h->ref_count[list]==2){

  853.                                 val= get_bits1(&s->gb)^1;

  854.                             }else{

  855.                                 val= get_ue_golomb_31(&s->gb);

  856.                                 if(val >= h->ref_count[list]){

  857.                                     av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);

  858.                                     return -1;

  859.                                 }

  860.                             }

  861.                         }else

  862.                             val= LIST_NOT_USED&0xFF;

  863.                         fill_rectangle(&h->ref_cache[list][ scan8[0] + 2*i ], 2, 4, 8, val, 1);

  864.                     }

  865.             }

  866.             for(list=0; list<h->list_count; list++){

  867.                 for(i=0; i<2; i++){

  868.                     unsigned int val;

  869.                     if(IS_DIR(mb_type, i, list)){

  870.                         pred_8x16_motion(h, i*4, list, h->ref_cache[list][ scan8[0] + 2*i ], &mx, &my);

  871.                         mx += get_se_golomb(&s->gb);

  872.                         my += get_se_golomb(&s->gb);

  873.                         tprintf(s->avctx, "final mv:%d %d\n", mx, my);

  874. 

  875.                         val= pack16to32(mx,my);

  876.                     }else

  877.                         val=0;

  878.                     fill_rectangle(h->mv_cache[list][ scan8[0] + 2*i ], 2, 4, 8, val, 4);

  879.                 }

  880.             }

  881.         }

  882.     }

  883. 

  884.     if(IS_INTER(mb_type))

  885.         write_back_motion(h, mb_type);

  886. 

  887.     if(!IS_INTRA16x16(mb_type)){

  888.         cbp= get_ue_golomb(&s->gb);

  889.         if(cbp > 47){

  890.             av_log(h->s.avctx, AV_LOG_ERROR, "cbp too large (%u) at %d %d\n", cbp, s->mb_x, s->mb_y);

  891.             return -1;

  892.         }

  893. 

  894.         if(CHROMA){

  895.             if(IS_INTRA4x4(mb_type)) cbp= golomb_to_intra4x4_cbp[cbp];

  896.             else                     cbp= golomb_to_inter_cbp   [cbp];

  897.         }else{

  898.             if(IS_INTRA4x4(mb_type)) cbp= golomb_to_intra4x4_cbp_gray[cbp];

  899.             else                     cbp= golomb_to_inter_cbp_gray[cbp];

  900.         }

  901.     }

  902. 

  903.     if(dct8x8_allowed && (cbp&15) && !IS_INTRA(mb_type)){

  904.         mb_type |= MB_TYPE_8x8DCT*get_bits1(&s->gb);

  905.     }

  906.     h->cbp=

  907.     h->cbp_table[mb_xy]= cbp;

  908.     s->current_picture.mb_type[mb_xy]= mb_type;

  909. 

  910.     if(cbp || IS_INTRA16x16(mb_type)){

  911.         int i8x8, i4x4, chroma_idx;

  912.         int dquant;

  913.         GetBitContext *gb= IS_INTRA(mb_type) ? h->intra_gb_ptr : h->inter_gb_ptr;

  914.         const uint8_t *scan, *scan8x8, *dc_scan;

  915. 

  916.         if(IS_INTERLACED(mb_type)){

  917.             scan8x8= s->qscale ? h->field_scan8x8_cavlc : h->field_scan8x8_cavlc_q0;

  918.             scan= s->qscale ? h->field_scan : h->field_scan_q0;

  919.             dc_scan= luma_dc_field_scan;

  920.         }else{

  921.             scan8x8= s->qscale ? h->zigzag_scan8x8_cavlc : h->zigzag_scan8x8_cavlc_q0;

  922.             scan= s->qscale ? h->zigzag_scan : h->zigzag_scan_q0;

  923.             dc_scan= luma_dc_zigzag_scan;

  924.         }

  925. 

  926.         dquant= get_se_golomb(&s->gb);

  927. 

  928.         s->qscale += dquant;

  929. 

  930.         if(((unsigned)s->qscale) > 51){

  931.             if(s->qscale<0) s->qscale+= 52;

  932.             else            s->qscale-= 52;

  933.             if(((unsigned)s->qscale) > 51){

  934.                 av_log(h->s.avctx, AV_LOG_ERROR, "dquant out of range (%d) at %d %d\n", dquant, s->mb_x, s->mb_y);

  935.                 return -1;

  936.             }

  937.         }

  938. 

  939.         h->chroma_qp[0]= get_chroma_qp(h, 0, s->qscale);

  940.         h->chroma_qp[1]= get_chroma_qp(h, 1, s->qscale);

  941.         if(IS_INTRA16x16(mb_type)){

  942.             if( decode_residual(h, h->intra_gb_ptr, h->mb, LUMA_DC_BLOCK_INDEX, dc_scan, h->dequant4_coeff[0][s->qscale], 16) < 0){

  943.                 return -1; //FIXME continue if partitioned and other return -1 too

  944.             }

  945. 

  946.             assert((cbp&15) == 0 || (cbp&15) == 15);

  947. 

  948.             if(cbp&15){

  949.                 for(i8x8=0; i8x8<4; i8x8++){

  950.                     for(i4x4=0; i4x4<4; i4x4++){

  951.                         const int index= i4x4 + 4*i8x8;

  952.                         if( decode_residual(h, h->intra_gb_ptr, h->mb + 16*index, index, scan + 1, h->dequant4_coeff[0][s->qscale], 15) < 0 ){

  953.                             return -1;

  954.                         }

  955.                     }

  956.                 }

  957.             }else{

  958.                 fill_rectangle(&h->non_zero_count_cache[scan8[0]], 4, 4, 8, 0, 1);

  959.             }

  960.         }else{

  961.             for(i8x8=0; i8x8<4; i8x8++){

  962.                 if(cbp & (1<<i8x8)){

  963.                     if(IS_8x8DCT(mb_type)){

  964.                         DCTELEM *buf = &h->mb[64*i8x8];

  965.                         uint8_t *nnz;

  966.                         for(i4x4=0; i4x4<4; i4x4++){

  967.                             if( decode_residual(h, gb, buf, i4x4+4*i8x8, scan8x8+16*i4x4,

  968.                                                 h->dequant8_coeff[IS_INTRA( mb_type ) ? 0:1][s->qscale], 16) <0 )

  969.                                 return -1;

  970.                         }

  971.                         nnz= &h->non_zero_count_cache[ scan8[4*i8x8] ];

  972.                         nnz[0] += nnz[1] + nnz[8] + nnz[9];

  973.                     }else{

  974.                         for(i4x4=0; i4x4<4; i4x4++){

  975.                             const int index= i4x4 + 4*i8x8;

  976. 

  977.                             if( decode_residual(h, gb, h->mb + 16*index, index, scan, h->dequant4_coeff[IS_INTRA( mb_type ) ? 0:3][s->qscale], 16) <0 ){

  978.                                 return -1;

  979.                             }

  980.                         }

  981.                     }

  982.                 }else{

  983.                     uint8_t * const nnz= &h->non_zero_count_cache[ scan8[4*i8x8] ];

  984.                     nnz[0] = nnz[1] = nnz[8] = nnz[9] = 0;

  985.                 }

  986.             }

  987.         }

  988. 

  989.         if(cbp&0x30){

  990.             for(chroma_idx=0; chroma_idx<2; chroma_idx++)

  991.                 if( decode_residual(h, gb, h->mb + 256 + 16*4*chroma_idx, CHROMA_DC_BLOCK_INDEX, chroma_dc_scan, NULL, 4) < 0){

  992.                     return -1;

  993.                 }

  994.         }

  995. 

  996.         if(cbp&0x20){

  997.             for(chroma_idx=0; chroma_idx<2; chroma_idx++){

  998.                 const uint32_t *qmul = h->dequant4_coeff[chroma_idx+1+(IS_INTRA( mb_type ) ? 0:3)][h->chroma_qp[chroma_idx]];

  999.                 for(i4x4=0; i4x4<4; i4x4++){

  1000.                     const int index= 16 + 4*chroma_idx + i4x4;

  1001.                     if( decode_residual(h, gb, h->mb + 16*index, index, scan + 1, qmul, 15) < 0){

  1002.                         return -1;

  1003.                     }

  1004.                 }

  1005.             }

  1006.         }else{

  1007.             uint8_t * const nnz= &h->non_zero_count_cache[0];

  1008.             nnz[ scan8[16]+0 ] = nnz[ scan8[16]+1 ] =nnz[ scan8[16]+8 ] =nnz[ scan8[16]+9 ] =

  1009.             nnz[ scan8[20]+0 ] = nnz[ scan8[20]+1 ] =nnz[ scan8[20]+8 ] =nnz[ scan8[20]+9 ] = 0;

  1010.         }

  1011.     }else{

  1012.         uint8_t * const nnz= &h->non_zero_count_cache[0];

  1013.         fill_rectangle(&nnz[scan8[0]], 4, 4, 8, 0, 1);

  1014.         nnz[ scan8[16]+0 ] = nnz[ scan8[16]+1 ] =nnz[ scan8[16]+8 ] =nnz[ scan8[16]+9 ] =

  1015.         nnz[ scan8[20]+0 ] = nnz[ scan8[20]+1 ] =nnz[ scan8[20]+8 ] =nnz[ scan8[20]+9 ] = 0;

  1016.     }

  1017.     s->current_picture.qscale_table[mb_xy]= s->qscale;

  1018.     write_back_non_zero_count(h);

  1019. 

  1020.     if(MB_MBAFF){

  1021.         h->ref_count[0] >>= 1;

  1022.         h->ref_count[1] >>= 1;

  1023.     }

  1024. 

  1025.     return 0;

  1026. }