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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. #include "intrax8dsp.h"

  32. 

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

  34. 

  35. #define DC_VLC_BITS 9

  36. #define AC_VLC_BITS 9

  37. #define OR_VLC_BITS 7

  38. 

  39. #define DC_VLC_MTD MAX_TABLE_DEPTH(DC_VLC_BITS, MAX_DC_VLC_BITS)

  40. #define AC_VLC_MTD MAX_TABLE_DEPTH(AC_VLC_BITS, MAX_AC_VLC_BITS)

  41. #define OR_VLC_MTD MAX_TABLE_DEPTH(OR_VLC_BITS, MAX_OR_VLC_BITS)

  42. 

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

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

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

  46. 

  47. static av_cold void x8_vlc_init(void){

  48.     int i;

  49.     int offset = 0;

  50.     int sizeidx = 0;

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

  52.         576, 548, 582, 618, 546, 616, 560, 642,

  53.         584, 582, 704, 664, 512, 544, 656, 640,

  54.         512, 648, 582, 566, 532, 614, 596, 648,

  55.         586, 552, 584, 590, 544, 578, 584, 624,

  56. 

  57.         528, 528, 526, 528, 536, 528, 526, 544,

  58.         544, 512, 512, 528, 528, 544, 512, 544,

  59. 

  60.         128, 128, 128, 128, 128, 128};

  61. 

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

  63. 

  64. #define  init_ac_vlc(dst,src) \

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

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

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

  68.        init_vlc(&dst, \

  69.               AC_VLC_BITS,77, \

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

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

  72.               INIT_VLC_USE_NEW_STATIC)

  73. //set ac tables

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

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

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

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

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

  79.     }

  80. #undef init_ac_vlc

  81. 

  82. //set dc tables

  83. #define init_dc_vlc(dst,src) \

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

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

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

  87.         init_vlc(&dst, \

  88.         DC_VLC_BITS,34, \

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

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

  91.         INIT_VLC_USE_NEW_STATIC);

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

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

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

  95.     }

  96. #undef init_dc_vlc

  97. 

  98. //set orient tables

  99. #define init_or_vlc(dst,src) \

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

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

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

  103.     init_vlc(&dst, \

  104.     OR_VLC_BITS,12, \

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

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

  107.     INIT_VLC_USE_NEW_STATIC);

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

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

  110.     }

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

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

  113.     }

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

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

  116. }

  117. #undef init_or_vlc

  118. 

  119. static void x8_reset_vlc_tables(IntraX8Context * w){

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

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

  122.     w->j_orient_vlc=NULL;

  123. }

  124. 

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

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

  127.     int table_index;

  128. 

  129.     av_assert2(mode<4);

  130. 

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

  132. 

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

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

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

  136. }

  137. 

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

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

  140.     int table_index;

  141. 

  142.     if(!w->j_orient_vlc ){

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

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

  145.     }

  146. 

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

  148. }

  149. 

  150. #define extra_bits(eb) (eb)

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

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

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

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

  155. static const uint32_t ac_decode_table[]={

  156.     /*46*/ extra_bits(3) |  extra_run  | run_offset(16) | level_offset( 0),

  157.     /*47*/ extra_bits(3) |  extra_run  | run_offset(24) | level_offset( 0),

  158.     /*48*/ extra_bits(2) |  extra_run  | run_offset( 4) | level_offset( 1),

  159.     /*49*/ extra_bits(3) |  extra_run  | run_offset( 8) | level_offset( 1),

  160. 

  161.     /*50*/ extra_bits(5) |  extra_run  | run_offset(32) | level_offset( 0),

  162.     /*51*/ extra_bits(4) |  extra_run  | run_offset(16) | level_offset( 1),

  163. 

  164.     /*52*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 4),

  165.     /*53*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 8),

  166.     /*54*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset(12),

  167.     /*55*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset(16),

  168.     /*56*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset(24),

  169. 

  170.     /*57*/ extra_bits(2) | extra_level | run_offset( 1) | level_offset( 3),

  171.     /*58*/ extra_bits(3) | extra_level | run_offset( 1) | level_offset( 7),

  172. 

  173.     /*59*/ extra_bits(2) |  extra_run  | run_offset(16) | level_offset( 0),

  174.     /*60*/ extra_bits(2) |  extra_run  | run_offset(20) | level_offset( 0),

  175.     /*61*/ extra_bits(2) |  extra_run  | run_offset(24) | level_offset( 0),

  176.     /*62*/ extra_bits(2) |  extra_run  | run_offset(28) | level_offset( 0),

  177.     /*63*/ extra_bits(4) |  extra_run  | run_offset(32) | level_offset( 0),

  178.     /*64*/ extra_bits(4) |  extra_run  | run_offset(48) | level_offset( 0),

  179. 

  180.     /*65*/ extra_bits(2) |  extra_run  | run_offset( 4) | level_offset( 1),

  181.     /*66*/ extra_bits(3) |  extra_run  | run_offset( 8) | level_offset( 1),

  182.     /*67*/ extra_bits(4) |  extra_run  | run_offset(16) | level_offset( 1),

  183. 

  184.     /*68*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 4),

  185.     /*69*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset( 8),

  186.     /*70*/ extra_bits(4) | extra_level | run_offset( 0) | level_offset(16),

  187. 

  188.     /*71*/ extra_bits(2) | extra_level | run_offset( 1) | level_offset( 3),

  189.     /*72*/ extra_bits(3) | extra_level | run_offset( 1) | level_offset( 7),

  190. };

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

  192. #undef extra_bits

  193. #undef extra_run

  194. #undef extra_level

  195. #undef run_offset

  196. #undef level_offset

  197. 

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

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

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

  201.     int i,e;

  202. 

  203. //    x8_select_ac_table(w,mode);

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

  205. 

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

  207.         int t,l;

  208.         if(i<0){

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

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

  211.             return;

  212.         }

  213. 

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

  215.         i-=23*t;

  216. /*

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

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

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

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

  221. 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

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

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

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

  225. 

  226.         (*run)   = i&t;

  227.         (*level) = l;

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

  229.         uint32_t sm;

  230.         uint32_t mask;

  231. 

  232.         i-=46;

  233.         sm=ac_decode_table[i];

  234. 

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

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

  237. 

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

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

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

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

  242.         static const uint8_t crazy_mix_runlevel[32]={

  243.         0x22,0x32,0x33,0x53,0x23,0x42,0x43,0x63,

  244.         0x24,0x52,0x34,0x73,0x25,0x62,0x44,0x83,

  245.         0x26,0x72,0x35,0x54,0x27,0x82,0x45,0x64,

  246.         0x28,0x92,0x36,0x74,0x29,0xa2,0x46,0x84};

  247. 

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

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

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

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

  252.     }else{

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

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

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

  256.     }

  257.     return;

  258. }

  259. 

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

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

  262. 

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

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

  265.     int i,e,c;

  266. 

  267.     av_assert2(mode<3);

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

  269.         int table_index;

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

  271.         //4 modes, same table

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

  273.     }

  274. 

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

  276. 

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

  278.     c= i>16;

  279.     (*final)=c;

  280.     i-=17*c;

  281. 

  282.     if(i<=0){

  283.         (*level)=0;

  284.         return -i;

  285.     }

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

  287.     c-=c>1;

  288. 

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

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

  291. 

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

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

  294.     return 0;

  295. }

  296. //end of huffman

  297. 

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

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

  300.     int range;

  301.     int sum;

  302.     int quant;

  303. 

  304.     w->dsp.setup_spatial_compensation(s->dest[chroma], s->edge_emu_buffer,

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

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

  307.     if(chroma){

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

  309.         quant=w->quant_dc_chroma;

  310.     }else{

  311.         quant=w->quant;

  312.     }

  313. 

  314.     w->flat_dc=0;

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

  316.         w->orient=0;

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

  318.             w->flat_dc=1;

  319.             sum+=9;

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

  321.         }

  322.     }

  323.     if(chroma)

  324.         return 0;

  325. 

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

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

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

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

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

  331.         }else{

  332.             w->orient=0;

  333.         }

  334.         w->raw_orient=0;

  335.     }else{

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

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

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

  339.             {8,0,4, 10,11, 1,7,2,6,9,3,5}

  340.         };

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

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

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

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

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

  346.     }

  347.     return 0;

  348. }

  349. 

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

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

  352. 

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

  354. /*

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

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

  357. */

  358. }

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

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

  361. 

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

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

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

  365. 

  366.     w->raw_orient=0;

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

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

  369.         return;

  370.     }

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

  372. }

  373. 

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

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

  376.     int a,b,c,i;

  377. 

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

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

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

  381. 

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

  383.         case 0:

  384.             break;

  385.         case 1:

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

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

  388.             w->orient  = 1;

  389.             return;

  390.         case 2:

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

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

  393.             w->orient  = 2;

  394.             return;

  395.         case 3:

  396.             w->est_run = 16;

  397.             w->orient  = 0;

  398.             return;

  399.     }

  400.     //no edge cases

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

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

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

  404. 

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

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

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

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

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

  410.     w->est_run>>=2;

  411. 

  412.     a&=3;

  413.     b&=3;

  414.     c&=3;

  415. 

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

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

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

  419. /*

  420. lut1[b][a]={

  421. ->{0, 1, 0, pad},

  422.   {0, 1, X, pad},

  423.   {2, 2, 2, pad}}

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

  425. -> 11 10 '10 10 '11 11'01 00 '11 00'01 00=>0xEAF4C4

  426. 

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

  428.   ->{0,2,1,pad},

  429.     {2,2,2,pad}}

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

  431. -> 11 10'10 10 '11 01'10 00=>0xEAD8

  432. */

  433. }

  434. 

  435. 

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

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

  438.     int t;

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

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

  441.     switch(direction){

  442.     case 0:

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

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

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

  446. 

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

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

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

  450. 

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

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

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

  454. 

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

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

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

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

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

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

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

  462. 

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

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

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

  466. 

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

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

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

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

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

  472. 

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

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

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

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

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

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

  479. 

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

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

  482. 

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

  484.         break;

  485.     case 1:

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

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

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

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

  490. 

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

  492.         break;

  493.     case 2:

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

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

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

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

  498. 

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

  500.         break;

  501.     }

  502. #undef B

  503. #undef T

  504. }

  505. 

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

  507.     int k;

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

  509.         memset(dst,pix,8);

  510.         dst+=linesize;

  511.     }

  512. }

  513. 

  514. static const int16_t quant_table[64] = {

  515.     256, 256, 256, 256,  256, 256, 259, 262,

  516.     265, 269, 272, 275,  278, 282, 285, 288,

  517.     292, 295, 299, 303,  306, 310, 314, 317,

  518.     321, 325, 329, 333,  337, 341, 345, 349,

  519.     353, 358, 362, 366,  371, 375, 379, 384,

  520.     389, 393, 398, 403,  408, 413, 417, 422,

  521.     428, 433, 438, 443,  448, 454, 459, 465,

  522.     470, 476, 482, 488,  493, 499, 505, 511

  523. };

  524. 

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

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

  527. 

  528.     uint8_t * scantable;

  529.     int final,run,level;

  530.     int ac_mode,dc_mode,est_run,dc_level;

  531.     int pos,n;

  532.     int zeros_only;

  533.     int use_quant_matrix;

  534.     int sign;

  535. 

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

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

  538. 

  539.     if(chroma){

  540.         dc_mode=2;

  541.     }else{

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

  543.     }

  544. 

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

  546.     n=0;

  547.     zeros_only=0;

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

  549.         use_quant_matrix=w->use_quant_matrix;

  550.         if(chroma){

  551.             ac_mode = 1;

  552.             est_run = 64;//not used

  553.         }else{

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

  555.                 use_quant_matrix = 0;

  556.             }

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

  558.                 ac_mode = 0;

  559.                 est_run = 64;

  560.             }else{

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

  562.                     ac_mode = 2;

  563.                     est_run=w->est_run;

  564.                 }else{

  565.                     ac_mode = 3;

  566.                     est_run = 64;

  567.                 }

  568.             }

  569.         }

  570.         x8_select_ac_table(w,ac_mode);

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

  572.         -> 10'01' 00'10' 10'00' 01'01' 01'00' 10'00 =>0x928548 */

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

  574.         pos=0;

  575.         do {

  576.             n++;

  577.             if( n >= est_run ){

  578.                 ac_mode=3;

  579.                 x8_select_ac_table(w,3);

  580.             }

  581. 

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

  583. 

  584.             pos+=run+1;

  585.             if(pos>63){

  586.                 //this also handles vlc error in x8_get_ac_rlf

  587.                 return -1;

  588.             }

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

  590.             level+= w->qsum;

  591. 

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

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

  594. 

  595.             if(use_quant_matrix){

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

  597.             }

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

  599.         }while(!final);

  600. 

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

  602.     }else{//DC only

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

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

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

  606.                                             w->divide_quant_dc_chroma;

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

  608.                                             w->quant_dc_chroma;

  609. 

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

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

  612. 

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

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

  615. 

  616.             goto block_placed;

  617.         }

  618.         zeros_only = (dc_level == 0);

  619.     }

  620.     if(!chroma){

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

  622.     }else{

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

  624.     }

  625. 

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

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

  628.         int direction;

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

  630.         -> 01'10' 10'10' 00'00' 00'01' 01'11' 11'00 =>0x6A017C */

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

  632.         if (direction != 3){

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

  634.         }

  635.     }

  636. 

  637.     if(w->flat_dc){

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

  639.     }else{

  640.         w->dsp.spatial_compensation[w->orient]( s->edge_emu_buffer,

  641.                                             s->dest[chroma],

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

  643.     }

  644.     if(!zeros_only)

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

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

  647.                           s->block[0] );

  648. 

  649. block_placed:

  650. 

  651.     if(!chroma){

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

  653.     }

  654. 

  655.     if(s->loop_filter){

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

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

  658. 

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

  660.             w->dsp.h_loop_filter(ptr, linesize, w->quant);

  661.         }

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

  663.             w->dsp.v_loop_filter(ptr, linesize, w->quant);

  664.         }

  665.     }

  666.     return 0;

  667. }

  668. 

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

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

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

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

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

  674. 

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

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

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

  678. 

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

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

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

  682. }

  683. 

  684. /**

  685.  * Initialize IntraX8 frame decoder.

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

  687.  * @param w pointer to IntraX8Context

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

  689.  */

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

  691. 

  692.     w->s=s;

  693.     x8_vlc_init();

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

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

  696. 

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

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

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

  700. 

  701.     ff_intrax8dsp_init(&w->dsp);

  702. }

  703. 

  704. /**

  705.  * Destroy IntraX8 frame structure.

  706.  * @param w pointer to IntraX8Context

  707.  */

  708. av_cold void ff_intrax8_common_end(IntraX8Context * w)

  709. {

  710.     av_freep(&w->prediction_table);

  711. }

  712. 

  713. /**

  714.  * Decode single IntraX8 frame.

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

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

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

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

  719.  * lowres decoding is theoretically impossible.

  720.  * @param w pointer to IntraX8Context

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

  722.  * @param quant_offset offset away from zero

  723.  */

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

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

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

  727.     int mb_xy;

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

  729. 

  730.     w->dquant = dquant;

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

  732.     w->qsum   = quant_offset;

  733. 

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

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

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

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

  738.     }else{

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

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

  741.     }

  742.     x8_reset_vlc_tables(w);

  743. 

  744.     s->resync_mb_x=0;

  745.     s->resync_mb_y=0;

  746. 

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

  748.         x8_init_block_index(s);

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

  750. 

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

  752.             x8_get_prediction(w);

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

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

  755. 

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

  757.                 x8_get_prediction_chroma(w);

  758. 

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

  760.                 so no error condition can be reached*/

  761.                 x8_setup_spatial_predictor(w,1);

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

  763. 

  764.                 x8_setup_spatial_predictor(w,2);

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

  766. 

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

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

  769. 

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

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

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

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

  774.                 mb_xy++;

  775.             }

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

  777.         }

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

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

  780.         }

  781.     }

  782. 

  783. error:

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

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

  786.                         ER_MB_END );

  787.     return 0;

  788. }