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FFmpeg/libavcodec/intrax8.c

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  1. /*

  2.  * This file is part of FFmpeg.

  3.  *

  4.  * FFmpeg is free software; you can redistribute it and/or

  5.  * modify it under the terms of the GNU Lesser General Public

  6.  * License as published by the Free Software Foundation; either

  7.  * version 2.1 of the License, or (at your option) any later version.

  8.  *

  9.  * FFmpeg is distributed in the hope that it will be useful,

  10.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  11.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  12.  * Lesser General Public License for more details.

  13.  *

  14.  * You should have received a copy of the GNU Lesser General Public

  15.  * License along with FFmpeg; if not, write to the Free Software

  16.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  17.  */

  18. 

  19. /**

  20.  * @file

  21.  * @brief IntraX8 (J-Frame) subdecoder, used by WMV2 and VC-1

  22.  */

  23. 

  24. #include "libavutil/avassert.h"

  25. #include "avcodec.h"

  26. #include "get_bits.h"

  27. #include "mpegvideo.h"

  28. #include "msmpeg4data.h"

  29. #include "intrax8huf.h"

  30. #include "intrax8.h"

  31. 

  32. #define MAX_TABLE_DEPTH(table_bits, max_bits) ((max_bits+table_bits-1)/table_bits)

  33. 

  34. #define DC_VLC_BITS 9

  35. #define AC_VLC_BITS 9

  36. #define OR_VLC_BITS 7

  37. 

  38. #define DC_VLC_MTD MAX_TABLE_DEPTH(DC_VLC_BITS, MAX_DC_VLC_BITS)

  39. #define AC_VLC_MTD MAX_TABLE_DEPTH(AC_VLC_BITS, MAX_AC_VLC_BITS)

  40. #define OR_VLC_MTD MAX_TABLE_DEPTH(OR_VLC_BITS, MAX_OR_VLC_BITS)

  41. 

  42. static VLC j_ac_vlc[2][2][8];  //[quant<13],[intra/inter],[select]

  43. static VLC j_dc_vlc[2][8];     //[quant], [select]

  44. static VLC j_orient_vlc[2][4]; //[quant], [select]

  45. 

  46. static av_cold void x8_vlc_init(void){

  47.     int i;

  48.     int offset = 0;

  49.     int sizeidx = 0;

  50.     static const uint16_t sizes[8*4 + 8*2 + 2 + 4] = {

  51.         576, 548, 582, 618, 546, 616, 560, 642,

  52.         584, 582, 704, 664, 512, 544, 656, 640,

  53.         512, 648, 582, 566, 532, 614, 596, 648,

  54.         586, 552, 584, 590, 544, 578, 584, 624,

  55. 

  56.         528, 528, 526, 528, 536, 528, 526, 544,

  57.         544, 512, 512, 528, 528, 544, 512, 544,

  58. 

  59.         128, 128, 128, 128, 128, 128};

  60. 

  61.     static VLC_TYPE table[28150][2];

  62. 

  63. #define  init_ac_vlc(dst,src) \

  64.     dst.table = &table[offset]; \

  65.     dst.table_allocated = sizes[sizeidx]; \

  66.     offset += sizes[sizeidx++]; \

  67.        init_vlc(&dst, \

  68.               AC_VLC_BITS,77, \

  69.               &src[1],4,2, \

  70.               &src[0],4,2, \

  71.               INIT_VLC_USE_NEW_STATIC)

  72. //set ac tables

  73.     for(i=0;i<8;i++){

  74.         init_ac_vlc( j_ac_vlc[0][0][i], x8_ac0_highquant_table[i][0] );

  75.         init_ac_vlc( j_ac_vlc[0][1][i], x8_ac1_highquant_table[i][0] );

  76.         init_ac_vlc( j_ac_vlc[1][0][i], x8_ac0_lowquant_table [i][0] );

  77.         init_ac_vlc( j_ac_vlc[1][1][i], x8_ac1_lowquant_table [i][0] );

  78.     }

  79. #undef init_ac_vlc

  80. 

  81. //set dc tables

  82. #define init_dc_vlc(dst,src) \

  83.     dst.table = &table[offset]; \

  84.     dst.table_allocated = sizes[sizeidx]; \

  85.     offset += sizes[sizeidx++]; \

  86.         init_vlc(&dst, \

  87.         DC_VLC_BITS,34, \

  88.         &src[1],4,2, \

  89.         &src[0],4,2, \

  90.         INIT_VLC_USE_NEW_STATIC);

  91.     for(i=0;i<8;i++){

  92.         init_dc_vlc( j_dc_vlc[0][i], x8_dc_highquant_table[i][0]);

  93.         init_dc_vlc( j_dc_vlc[1][i], x8_dc_lowquant_table [i][0]);

  94.     }

  95. #undef init_dc_vlc

  96. 

  97. //set orient tables

  98. #define init_or_vlc(dst,src) \

  99.     dst.table = &table[offset]; \

  100.     dst.table_allocated = sizes[sizeidx]; \

  101.     offset += sizes[sizeidx++]; \

  102.     init_vlc(&dst, \

  103.     OR_VLC_BITS,12, \

  104.     &src[1],4,2, \

  105.     &src[0],4,2, \

  106.     INIT_VLC_USE_NEW_STATIC);

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

  108.         init_or_vlc( j_orient_vlc[0][i], x8_orient_highquant_table[i][0]);

  109.     }

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

  111.         init_or_vlc( j_orient_vlc[1][i], x8_orient_lowquant_table [i][0])

  112.     }

  113.     if (offset != sizeof(table)/sizeof(VLC_TYPE)/2)

  114.         av_log(NULL, AV_LOG_ERROR, "table size %i does not match needed %i\n", (int)(sizeof(table)/sizeof(VLC_TYPE)/2), offset);

  115. }

  116. #undef init_or_vlc

  117. 

  118. static void x8_reset_vlc_tables(IntraX8Context * w){

  119.     memset(w->j_dc_vlc,0,sizeof(w->j_dc_vlc));

  120.     memset(w->j_ac_vlc,0,sizeof(w->j_ac_vlc));

  121.     w->j_orient_vlc=NULL;

  122. }

  123. 

  124. static inline void x8_select_ac_table(IntraX8Context * const w , int mode){

  125.     MpegEncContext * const s= w->s;

  126.     int table_index;

  127. 

  128.     av_assert2(mode<4);

  129. 

  130.     if( w->j_ac_vlc[mode] ) return;

  131. 

  132.     table_index = get_bits(&s->gb, 3);

  133.     w->j_ac_vlc[mode] = &j_ac_vlc[w->quant<13][mode>>1][table_index];//2 modes use same tables

  134.     av_assert2(w->j_ac_vlc[mode]);

  135. }

  136. 

  137. static inline int x8_get_orient_vlc(IntraX8Context * w){

  138.     MpegEncContext * const s= w->s;

  139.     int table_index;

  140. 

  141.     if(!w->j_orient_vlc ){

  142.         table_index = get_bits(&s->gb, 1+(w->quant<13) );

  143.         w->j_orient_vlc = &j_orient_vlc[w->quant<13][table_index];

  144.     }

  145. 

  146.     return get_vlc2(&s->gb, w->j_orient_vlc->table, OR_VLC_BITS, OR_VLC_MTD);

  147. }

  148. 

  149. #define extra_bits(eb) (eb)

  150. #define extra_run   (0xFF<<8)

  151. #define extra_level (0x00<<8)

  152. #define   run_offset(r)    ((r)<<16)

  153. #define level_offset(l)    ((l)<<24)

  154. static const uint32_t ac_decode_table[]={

  155.     /*46*/ extra_bits(3) |  extra_run  | run_offset(16) | level_offset( 0),

  156.     /*47*/ extra_bits(3) |  extra_run  | run_offset(24) | level_offset( 0),

  157.     /*48*/ extra_bits(2) |  extra_run  | run_offset( 4) | level_offset( 1),

  158.     /*49*/ extra_bits(3) |  extra_run  | run_offset( 8) | level_offset( 1),

  159. 

  160.     /*50*/ extra_bits(5) |  extra_run  | run_offset(32) | level_offset( 0),

  161.     /*51*/ extra_bits(4) |  extra_run  | run_offset(16) | level_offset( 1),

  162. 

  163.     /*52*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 4),

  164.     /*53*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 8),

  165.     /*54*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset(12),

  166.     /*55*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset(16),

  167.     /*56*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset(24),

  168. 

  169.     /*57*/ extra_bits(2) | extra_level | run_offset( 1) | level_offset( 3),

  170.     /*58*/ extra_bits(3) | extra_level | run_offset( 1) | level_offset( 7),

  171. 

  172.     /*59*/ extra_bits(2) |  extra_run  | run_offset(16) | level_offset( 0),

  173.     /*60*/ extra_bits(2) |  extra_run  | run_offset(20) | level_offset( 0),

  174.     /*61*/ extra_bits(2) |  extra_run  | run_offset(24) | level_offset( 0),

  175.     /*62*/ extra_bits(2) |  extra_run  | run_offset(28) | level_offset( 0),

  176.     /*63*/ extra_bits(4) |  extra_run  | run_offset(32) | level_offset( 0),

  177.     /*64*/ extra_bits(4) |  extra_run  | run_offset(48) | level_offset( 0),

  178. 

  179.     /*65*/ extra_bits(2) |  extra_run  | run_offset( 4) | level_offset( 1),

  180.     /*66*/ extra_bits(3) |  extra_run  | run_offset( 8) | level_offset( 1),

  181.     /*67*/ extra_bits(4) |  extra_run  | run_offset(16) | level_offset( 1),

  182. 

  183.     /*68*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 4),

  184.     /*69*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset( 8),

  185.     /*70*/ extra_bits(4) | extra_level | run_offset( 0) | level_offset(16),

  186. 

  187.     /*71*/ extra_bits(2) | extra_level | run_offset( 1) | level_offset( 3),

  188.     /*72*/ extra_bits(3) | extra_level | run_offset( 1) | level_offset( 7),

  189. };

  190. //extra_bits = 3bits; extra_run/level = 1 bit; run_offset = 6bits; level_offset = 5 bits;

  191. #undef extra_bits

  192. #undef extra_run

  193. #undef extra_level

  194. #undef run_offset

  195. #undef level_offset

  196. 

  197. static void x8_get_ac_rlf(IntraX8Context * const w, const int mode,

  198.                      int * const run, int * const level, int * const final){

  199.     MpegEncContext *  const s= w->s;

  200.     int i,e;

  201. 

  202. //    x8_select_ac_table(w,mode);

  203.     i = get_vlc2(&s->gb, w->j_ac_vlc[mode]->table, AC_VLC_BITS, AC_VLC_MTD);

  204. 

  205.     if(i<46){ //[0-45]

  206.         int t,l;

  207.         if(i<0){

  208.             (*level)=(*final)=//prevent 'may be used unilitialized'

  209.             (*run)=64;//this would cause error exit in the ac loop

  210.             return;

  211.         }

  212. 

  213.         (*final) = t = (i>22);

  214.         i-=23*t;

  215. /*

  216.   i== 0-15 r=0-15 l=0 ;r=i& %01111

  217.   i==16-19 r=0-3  l=1 ;r=i& %00011

  218.   i==20-21 r=0-1  l=2 ;r=i& %00001

  219.   i==22    r=0    l=3 ;r=i& %00000

  220. l=lut_l[i/2]={0,0,0,0,0,0,0,0,1,1,2,3}[i>>1];// 11 10'01 01'00 00'00 00'00 00'00 00 => 0xE50000

  221. t=lut_mask[l]={0x0f,0x03,0x01,0x00}[l]; as i<256 the higher bits do not matter */

  222.         l=(0xE50000>>(i&(0x1E)))&3;/*0x1E or (~1) or ((i>>1)<<1)*/

  223.         t=(0x01030F>>(l<<3));

  224. 

  225.         (*run)   = i&t;

  226.         (*level) = l;

  227.     }else if(i<73){//[46-72]

  228.         uint32_t sm;

  229.         uint32_t mask;

  230. 

  231.         i-=46;

  232.         sm=ac_decode_table[i];

  233. 

  234.         e=get_bits(&s->gb,sm&0xF);sm>>=8;//3bits

  235.         mask=sm&0xff;sm>>=8;             //1bit

  236. 

  237.         (*run)  =(sm&0xff) + (e&( mask));//6bits

  238.         (*level)=(sm>>8)   + (e&(~mask));//5bits

  239.         (*final)=i>(58-46);

  240.     }else if(i<75){//[73-74]

  241.         static const uint8_t crazy_mix_runlevel[32]={

  242.         0x22,0x32,0x33,0x53,0x23,0x42,0x43,0x63,

  243.         0x24,0x52,0x34,0x73,0x25,0x62,0x44,0x83,

  244.         0x26,0x72,0x35,0x54,0x27,0x82,0x45,0x64,

  245.         0x28,0x92,0x36,0x74,0x29,0xa2,0x46,0x84};

  246. 

  247.         (*final)=!(i&1);

  248.         e=get_bits(&s->gb,5);//get the extra bits

  249.         (*run)  =crazy_mix_runlevel[e]>>4;

  250.         (*level)=crazy_mix_runlevel[e]&0x0F;

  251.     }else{

  252.         (*level)=get_bits( &s->gb, 7-3*(i&1));

  253.         (*run)  =get_bits( &s->gb, 6);

  254.         (*final)=get_bits1(&s->gb);

  255.     }

  256.     return;

  257. }

  258. 

  259. //static const uint8_t dc_extra_sbits[]   ={0, 1,1, 1,1, 2,2, 3,3,   4,4,   5,5,   6,6,    7,7    };

  260. static const uint8_t dc_index_offset[]  ={ 0, 1,2, 3,4, 5,7, 9,13, 17,25, 33,49, 65,97, 129,193};

  261. 

  262. static int x8_get_dc_rlf(IntraX8Context * const w,int const mode, int * const level, int * const final){

  263.     MpegEncContext * const s= w->s;

  264.     int i,e,c;

  265. 

  266.     av_assert2(mode<3);

  267.     if( !w->j_dc_vlc[mode] ) {

  268.         int table_index;

  269.         table_index = get_bits(&s->gb, 3);

  270.         //4 modes, same table

  271.         w->j_dc_vlc[mode]= &j_dc_vlc[w->quant<13][table_index];

  272.     }

  273. 

  274.     i=get_vlc2(&s->gb, w->j_dc_vlc[mode]->table, DC_VLC_BITS, DC_VLC_MTD);

  275. 

  276.     /*(i>=17) {i-=17;final=1;}*/

  277.     c= i>16;

  278.     (*final)=c;

  279.     i-=17*c;

  280. 

  281.     if(i<=0){

  282.         (*level)=0;

  283.         return -i;

  284.     }

  285.     c=(i+1)>>1;//hackish way to calculate dc_extra_sbits[]

  286.     c-=c>1;

  287. 

  288.     e=get_bits(&s->gb,c);//get the extra bits

  289.     i=dc_index_offset[i]+(e>>1);

  290. 

  291.     e= -(e & 1);//0,0xffffff

  292.     (*level)= (i ^ e) - e;// (i^0)-0 , (i^0xff)-(-1)

  293.     return 0;

  294. }

  295. //end of huffman

  296. 

  297. static int x8_setup_spatial_predictor(IntraX8Context * const w, const int chroma){

  298.     MpegEncContext * const s= w->s;

  299.     int range;

  300.     int sum;

  301.     int quant;

  302. 

  303.     s->dsp.x8_setup_spatial_compensation(s->dest[chroma], s->edge_emu_buffer,

  304.                                           s->current_picture.f.linesize[chroma>0],

  305.                                           &range, &sum, w->edges);

  306.     if(chroma){

  307.         w->orient=w->chroma_orient;

  308.         quant=w->quant_dc_chroma;

  309.     }else{

  310.         quant=w->quant;

  311.     }

  312. 

  313.     w->flat_dc=0;

  314.     if(range < quant || range < 3){

  315.         w->orient=0;

  316.         if(range < 3){//yep you read right, a +-1 idct error may break decoding!

  317.             w->flat_dc=1;

  318.             sum+=9;

  319.             w->predicted_dc = (sum*6899)>>17;//((1<<17)+9)/(8+8+1+2)=6899

  320.         }

  321.     }

  322.     if(chroma)

  323.         return 0;

  324. 

  325.     av_assert2(w->orient < 3);

  326.     if(range < 2*w->quant){

  327.         if( (w->edges&3) == 0){

  328.             if(w->orient==1) w->orient=11;

  329.             if(w->orient==2) w->orient=10;

  330.         }else{

  331.             w->orient=0;

  332.         }

  333.         w->raw_orient=0;

  334.     }else{

  335.         static const uint8_t prediction_table[3][12]={

  336.             {0,8,4, 10,11, 2,6,9,1,3,5,7},

  337.             {4,0,8, 11,10, 3,5,2,6,9,1,7},

  338.             {8,0,4, 10,11, 1,7,2,6,9,3,5}

  339.         };

  340.         w->raw_orient=x8_get_orient_vlc(w);

  341.         if(w->raw_orient<0) return -1;

  342.         av_assert2(w->raw_orient < 12 );

  343.         av_assert2(w->orient<3);

  344.         w->orient=prediction_table[w->orient][w->raw_orient];

  345.     }

  346.     return 0;

  347. }

  348. 

  349. static void x8_update_predictions(IntraX8Context * const w, const int orient, const int est_run ){

  350.     MpegEncContext * const s= w->s;

  351. 

  352.     w->prediction_table[s->mb_x*2+(s->mb_y&1)] = (est_run<<2) + 1*(orient==4) + 2*(orient==8);

  353. /*

  354.   y=2n+0 ->//0 2 4

  355.   y=2n+1 ->//1 3 5

  356. */

  357. }

  358. static void x8_get_prediction_chroma(IntraX8Context * const w){

  359.     MpegEncContext * const s= w->s;

  360. 

  361.     w->edges = 1*( !(s->mb_x>>1) );

  362.     w->edges|= 2*( !(s->mb_y>>1) );

  363.     w->edges|= 4*( s->mb_x >= (2*s->mb_width-1) );//mb_x for chroma would always be odd

  364. 

  365.     w->raw_orient=0;

  366.     if(w->edges&3){//lut_co[8]={inv,4,8,8, inv,4,8,8}<- =>{1,1,0,0;1,1,0,0} => 0xCC

  367.         w->chroma_orient=4<<((0xCC>>w->edges)&1);

  368.         return;

  369.     }

  370.     w->chroma_orient = (w->prediction_table[2*s->mb_x-2] & 0x03)<<2;//block[x-1][y|1-1)]

  371. }

  372. 

  373. static void x8_get_prediction(IntraX8Context * const w){

  374.     MpegEncContext * const s= w->s;

  375.     int a,b,c,i;

  376. 

  377.     w->edges = 1*( !s->mb_x );

  378.     w->edges|= 2*( !s->mb_y );

  379.     w->edges|= 4*( s->mb_x >= (2*s->mb_width-1) );

  380. 

  381.     switch(w->edges&3){

  382.         case 0:

  383.             break;

  384.         case 1:

  385.             //take the one from the above block[0][y-1]

  386.             w->est_run = w->prediction_table[!(s->mb_y&1)]>>2;

  387.             w->orient  = 1;

  388.             return;

  389.         case 2:

  390.             //take the one from the previous block[x-1][0]

  391.             w->est_run = w->prediction_table[2*s->mb_x-2]>>2;

  392.             w->orient  = 2;

  393.             return;

  394.         case 3:

  395.             w->est_run = 16;

  396.             w->orient  = 0;

  397.             return;

  398.     }

  399.     //no edge cases

  400.     b= w->prediction_table[2*s->mb_x   + !(s->mb_y&1) ];//block[x  ][y-1]

  401.     a= w->prediction_table[2*s->mb_x-2 +  (s->mb_y&1) ];//block[x-1][y  ]

  402.     c= w->prediction_table[2*s->mb_x-2 + !(s->mb_y&1) ];//block[x-1][y-1]

  403. 

  404.     w->est_run = FFMIN(b,a);

  405.     /* This condition has nothing to do with w->edges, even if it looks

  406.        similar it would trigger if e.g. x=3;y=2;

  407.        I guess somebody wrote something wrong and it became standard. */

  408.     if( (s->mb_x & s->mb_y) != 0 ) w->est_run=FFMIN(c,w->est_run);

  409.     w->est_run>>=2;

  410. 

  411.     a&=3;

  412.     b&=3;

  413.     c&=3;

  414. 

  415.     i=( 0xFFEAF4C4>>(2*b+8*a) )&3;

  416.     if(i!=3) w->orient=i;

  417.     else     w->orient=( 0xFFEAD8>>(2*c+8*(w->quant>12)) )&3;

  418. /*

  419. lut1[b][a]={

  420. ->{0, 1, 0, pad},

  421.   {0, 1, X, pad},

  422.   {2, 2, 2, pad}}

  423.    pad 2   2  2; pad X  1  0; pad 0  1  0 <-

  424. -> 11 10 '10 10 '11 11'01 00 '11 00'01 00=>0xEAF4C4

  425. 

  426. lut2[q>12][c]={

  427.   ->{0,2,1,pad},

  428.     {2,2,2,pad}}

  429.    pad 2  2  2; pad 1  2  0 <-

  430. -> 11 10'10 10 '11 01'10 00=>0xEAD8

  431. */

  432. }

  433. 

  434. 

  435. static void x8_ac_compensation(IntraX8Context * const w, int const direction, int const dc_level){

  436.     MpegEncContext * const s= w->s;

  437.     int t;

  438. #define B(x,y)  s->block[0][s->dsp.idct_permutation[(x)+(y)*8]]

  439. #define T(x)  ((x) * dc_level + 0x8000) >> 16;

  440.     switch(direction){

  441.     case 0:

  442.         t = T(3811);//h

  443.         B(1,0) -= t;

  444.         B(0,1) -= t;

  445. 

  446.         t = T(487);//e

  447.         B(2,0) -= t;

  448.         B(0,2) -= t;

  449. 

  450.         t = T(506);//f

  451.         B(3,0) -= t;

  452.         B(0,3) -= t;

  453. 

  454.         t = T(135);//c

  455.         B(4,0) -= t;

  456.         B(0,4) -= t;

  457.         B(2,1) += t;

  458.         B(1,2) += t;

  459.         B(3,1) += t;

  460.         B(1,3) += t;

  461. 

  462.         t = T(173);//d

  463.         B(5,0) -= t;

  464.         B(0,5) -= t;

  465. 

  466.         t = T(61);//b

  467.         B(6,0) -= t;

  468.         B(0,6) -= t;

  469.         B(5,1) += t;

  470.         B(1,5) += t;

  471. 

  472.         t = T(42); //a

  473.         B(7,0) -= t;

  474.         B(0,7) -= t;

  475.         B(4,1) += t;

  476.         B(1,4) += t;

  477.         B(4,4) += t;

  478. 

  479.         t = T(1084);//g

  480.         B(1,1) += t;

  481. 

  482.         s->block_last_index[0] = FFMAX(s->block_last_index[0], 7*8);

  483.         break;

  484.     case 1:

  485.         B(0,1) -= T(6269);

  486.         B(0,3) -= T( 708);

  487.         B(0,5) -= T( 172);

  488.         B(0,7) -= T(  73);

  489. 

  490.         s->block_last_index[0] = FFMAX(s->block_last_index[0], 7*8);

  491.         break;

  492.     case 2:

  493.         B(1,0) -= T(6269);

  494.         B(3,0) -= T( 708);

  495.         B(5,0) -= T( 172);

  496.         B(7,0) -= T(  73);

  497. 

  498.         s->block_last_index[0] = FFMAX(s->block_last_index[0], 7);

  499.         break;

  500.     }

  501. #undef B

  502. #undef T

  503. }

  504. 

  505. static void dsp_x8_put_solidcolor(uint8_t const pix, uint8_t * dst, int const linesize){

  506.     int k;

  507.     for(k=0;k<8;k++){

  508.         memset(dst,pix,8);

  509.         dst+=linesize;

  510.     }

  511. }

  512. 

  513. static const int16_t quant_table[64] = {

  514.     256, 256, 256, 256,  256, 256, 259, 262,

  515.     265, 269, 272, 275,  278, 282, 285, 288,

  516.     292, 295, 299, 303,  306, 310, 314, 317,

  517.     321, 325, 329, 333,  337, 341, 345, 349,

  518.     353, 358, 362, 366,  371, 375, 379, 384,

  519.     389, 393, 398, 403,  408, 413, 417, 422,

  520.     428, 433, 438, 443,  448, 454, 459, 465,

  521.     470, 476, 482, 488,  493, 499, 505, 511

  522. };

  523. 

  524. static int x8_decode_intra_mb(IntraX8Context* const w, const int chroma){

  525.     MpegEncContext * const s= w->s;

  526. 

  527.     uint8_t * scantable;

  528.     int final,run,level;

  529.     int ac_mode,dc_mode,est_run,dc_level;

  530.     int pos,n;

  531.     int zeros_only;

  532.     int use_quant_matrix;

  533.     int sign;

  534. 

  535.     av_assert2(w->orient<12);

  536.     s->dsp.clear_block(s->block[0]);

  537. 

  538.     if(chroma){

  539.         dc_mode=2;

  540.     }else{

  541.         dc_mode=!!w->est_run;//0,1

  542.     }

  543. 

  544.     if(x8_get_dc_rlf(w, dc_mode, &dc_level, &final)) return -1;

  545.     n=0;

  546.     zeros_only=0;

  547.     if(!final){//decode ac

  548.         use_quant_matrix=w->use_quant_matrix;

  549.         if(chroma){

  550.             ac_mode = 1;

  551.             est_run = 64;//not used

  552.         }else{

  553.             if (w->raw_orient < 3){

  554.                 use_quant_matrix = 0;

  555.             }

  556.             if(w->raw_orient > 4){

  557.                 ac_mode = 0;

  558.                 est_run = 64;

  559.             }else{

  560.                 if(w->est_run > 1){

  561.                     ac_mode = 2;

  562.                     est_run=w->est_run;

  563.                 }else{

  564.                     ac_mode = 3;

  565.                     est_run = 64;

  566.                 }

  567.             }

  568.         }

  569.         x8_select_ac_table(w,ac_mode);

  570.         /*scantable_selector[12]={0,2,0,1,1,1,0,2,2,0,1,2};<-

  571.         -> 10'01' 00'10' 10'00' 01'01' 01'00' 10'00 =>0x928548 */

  572.         scantable = w->scantable[ (0x928548>>(2*w->orient))&3 ].permutated;

  573.         pos=0;

  574.         do {

  575.             n++;

  576.             if( n >= est_run ){

  577.                 ac_mode=3;

  578.                 x8_select_ac_table(w,3);

  579.             }

  580. 

  581.             x8_get_ac_rlf(w,ac_mode,&run,&level,&final);

  582. 

  583.             pos+=run+1;

  584.             if(pos>63){

  585.                 //this also handles vlc error in x8_get_ac_rlf

  586.                 return -1;

  587.             }

  588.             level= (level+1) * w->dquant;

  589.             level+= w->qsum;

  590. 

  591.             sign = - get_bits1(&s->gb);

  592.             level = (level ^ sign) - sign;

  593. 

  594.             if(use_quant_matrix){

  595.                 level = (level*quant_table[pos])>>8;

  596.             }

  597.             s->block[0][ scantable[pos] ]=level;

  598.         }while(!final);

  599. 

  600.         s->block_last_index[0]=pos;

  601.     }else{//DC only

  602.         s->block_last_index[0]=0;

  603.         if(w->flat_dc && ((unsigned)(dc_level+1)) < 3){//[-1;1]

  604.             int32_t divide_quant= !chroma ? w->divide_quant_dc_luma:

  605.                                             w->divide_quant_dc_chroma;

  606.             int32_t dc_quant    = !chroma ? w->quant:

  607.                                             w->quant_dc_chroma;

  608. 

  609.             //original intent dc_level+=predicted_dc/quant; but it got lost somewhere in the rounding

  610.             dc_level+= (w->predicted_dc*divide_quant + (1<<12) )>>13;

  611. 

  612.             dsp_x8_put_solidcolor( av_clip_uint8((dc_level*dc_quant+4)>>3),

  613.                                    s->dest[chroma], s->current_picture.f.linesize[!!chroma]);

  614. 

  615.             goto block_placed;

  616.         }

  617.         zeros_only = (dc_level == 0);

  618.     }

  619.     if(!chroma){

  620.         s->block[0][0] = dc_level*w->quant;

  621.     }else{

  622.         s->block[0][0] = dc_level*w->quant_dc_chroma;

  623.     }

  624. 

  625.     //there is !zero_only check in the original, but dc_level check is enough

  626.     if( (unsigned int)(dc_level+1) >= 3 && (w->edges&3) != 3 ){

  627.         int direction;

  628.         /*ac_comp_direction[orient] = { 0, 3, 3, 1, 1, 0, 0, 0, 2, 2, 2, 1 };<-

  629.         -> 01'10' 10'10' 00'00' 00'01' 01'11' 11'00 =>0x6A017C */

  630.         direction= (0x6A017C>>(w->orient*2))&3;

  631.         if (direction != 3){

  632.             x8_ac_compensation(w, direction, s->block[0][0]);//modify block_last[]

  633.         }

  634.     }

  635. 

  636.     if(w->flat_dc){

  637.         dsp_x8_put_solidcolor(w->predicted_dc, s->dest[chroma], s->current_picture.f.linesize[!!chroma]);

  638.     }else{

  639.         s->dsp.x8_spatial_compensation[w->orient]( s->edge_emu_buffer,

  640.                                             s->dest[chroma],

  641.                                             s->current_picture.f.linesize[!!chroma] );

  642.     }

  643.     if(!zeros_only)

  644.         s->dsp.idct_add ( s->dest[chroma],

  645.                           s->current_picture.f.linesize[!!chroma],

  646.                           s->block[0] );

  647. 

  648. block_placed:

  649. 

  650.     if(!chroma){

  651.         x8_update_predictions(w,w->orient,n);

  652.     }

  653. 

  654.     if(s->loop_filter){

  655.         uint8_t* ptr = s->dest[chroma];

  656.         int linesize = s->current_picture.f.linesize[!!chroma];

  657. 

  658.         if(!( (w->edges&2) || ( zeros_only && (w->orient|4)==4 ) )){

  659.             s->dsp.x8_h_loop_filter(ptr, linesize, w->quant);

  660.         }

  661.         if(!( (w->edges&1) || ( zeros_only && (w->orient|8)==8 ) )){

  662.             s->dsp.x8_v_loop_filter(ptr, linesize, w->quant);

  663.         }

  664.     }

  665.     return 0;

  666. }

  667. 

  668. static void x8_init_block_index(MpegEncContext *s){ //FIXME maybe merge with ff_*

  669. //not s->linesize as this would be wrong for field pics

  670. //not that IntraX8 has interlacing support ;)

  671.     const int linesize   = s->current_picture.f.linesize[0];

  672.     const int uvlinesize = s->current_picture.f.linesize[1];

  673. 

  674.     s->dest[0] = s->current_picture.f.data[0];

  675.     s->dest[1] = s->current_picture.f.data[1];

  676.     s->dest[2] = s->current_picture.f.data[2];

  677. 

  678.     s->dest[0] +=   s->mb_y        *   linesize << 3;

  679.     s->dest[1] += ( s->mb_y&(~1) ) * uvlinesize << 2;//chroma blocks are on add rows

  680.     s->dest[2] += ( s->mb_y&(~1) ) * uvlinesize << 2;

  681. }

  682. 

  683. /**

  684.  * Initialize IntraX8 frame decoder.

  685.  * Requires valid MpegEncContext with valid s->mb_width before calling.

  686.  * @param w pointer to IntraX8Context

  687.  * @param s pointer to MpegEncContext of the parent codec

  688.  */

  689. av_cold void ff_intrax8_common_init(IntraX8Context * w, MpegEncContext * const s){

  690. 

  691.     w->s=s;

  692.     x8_vlc_init();

  693.     av_assert0(s->mb_width>0);

  694.     w->prediction_table=av_mallocz(s->mb_width*2*2);//two rows, 2 blocks per cannon mb

  695. 

  696.     ff_init_scantable(s->dsp.idct_permutation, &w->scantable[0], ff_wmv1_scantable[0]);

  697.     ff_init_scantable(s->dsp.idct_permutation, &w->scantable[1], ff_wmv1_scantable[2]);

  698.     ff_init_scantable(s->dsp.idct_permutation, &w->scantable[2], ff_wmv1_scantable[3]);

  699. }

  700. 

  701. /**

  702.  * Destroy IntraX8 frame structure.

  703.  * @param w pointer to IntraX8Context

  704.  */

  705. av_cold void ff_intrax8_common_end(IntraX8Context * w)

  706. {

  707.     av_freep(&w->prediction_table);

  708. }

  709. 

  710. /**

  711.  * Decode single IntraX8 frame.

  712.  * The parent codec must fill s->loopfilter and s->gb (bitstream).

  713.  * The parent codec must call MPV_frame_start(), ff_er_frame_start() before calling this function.

  714.  * The parent codec must call ff_er_frame_end(), MPV_frame_end() after calling this function.

  715.  * This function does not use MPV_decode_mb().

  716.  * lowres decoding is theoretically impossible.

  717.  * @param w pointer to IntraX8Context

  718.  * @param dquant doubled quantizer, it would be odd in case of VC-1 halfpq==1.

  719.  * @param quant_offset offset away from zero

  720.  */

  721. //FIXME extern uint8_t ff_wmv3_dc_scale_table[32];

  722. int ff_intrax8_decode_picture(IntraX8Context * const w, int dquant, int quant_offset){

  723.     MpegEncContext * const s= w->s;

  724.     int mb_xy;

  725.     w->use_quant_matrix = get_bits1(&s->gb);

  726. 

  727.     w->dquant = dquant;

  728.     w->quant  = dquant >> 1;

  729.     w->qsum   = quant_offset;

  730. 

  731.     w->divide_quant_dc_luma = ((1<<16) + (w->quant>>1)) / w->quant;

  732.     if(w->quant < 5){

  733.         w->quant_dc_chroma =  w->quant;

  734.         w->divide_quant_dc_chroma = w->divide_quant_dc_luma;

  735.     }else{

  736.         w->quant_dc_chroma =  w->quant+((w->quant+3)>>3);

  737.         w->divide_quant_dc_chroma = ((1<<16) + (w->quant_dc_chroma>>1)) / w->quant_dc_chroma;

  738.     }

  739.     x8_reset_vlc_tables(w);

  740. 

  741.     s->resync_mb_x=0;

  742.     s->resync_mb_y=0;

  743. 

  744.     for(s->mb_y=0; s->mb_y < s->mb_height*2; s->mb_y++){

  745.         x8_init_block_index(s);

  746.         mb_xy=(s->mb_y>>1)*s->mb_stride;

  747. 

  748.         for(s->mb_x=0; s->mb_x < s->mb_width*2; s->mb_x++){

  749.             x8_get_prediction(w);

  750.             if(x8_setup_spatial_predictor(w,0)) goto error;

  751.             if(x8_decode_intra_mb(w,0)) goto error;

  752. 

  753.             if( s->mb_x & s->mb_y & 1 ){

  754.                 x8_get_prediction_chroma(w);

  755. 

  756.                 /*when setting up chroma, no vlc is read,

  757.                 so no error condition can be reached*/

  758.                 x8_setup_spatial_predictor(w,1);

  759.                 if(x8_decode_intra_mb(w,1)) goto error;

  760. 

  761.                 x8_setup_spatial_predictor(w,2);

  762.                 if(x8_decode_intra_mb(w,2)) goto error;

  763. 

  764.                 s->dest[1]+= 8;

  765.                 s->dest[2]+= 8;

  766. 

  767.                 /*emulate MB info in the relevant tables*/

  768.                 s->mbskip_table [mb_xy]=0;

  769.                 s->mbintra_table[mb_xy]=1;

  770.                 s->current_picture.f.qscale_table[mb_xy] = w->quant;

  771.                 mb_xy++;

  772.             }

  773.             s->dest[0]+= 8;

  774.         }

  775.         if(s->mb_y&1){

  776.             ff_draw_horiz_band(s, (s->mb_y-1)*8, 16);

  777.         }

  778.     }

  779. 

  780. error:

  781.     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y,

  782.                         (s->mb_x>>1)-1, (s->mb_y>>1)-1,

  783.                         ER_MB_END );

  784.     return 0;

  785. }