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 "error_resilience.h"
27#include "get_bits.h"
28#include "idctdsp.h"
29#include "mpegvideo.h"
30#include "msmpeg4data.h"
31#include "intrax8huf.h"
32#include "intrax8.h"
33#include "intrax8dsp.h"
34
35#define MAX_TABLE_DEPTH(table_bits, max_bits) ((max_bits+table_bits-1)/table_bits)
36
37#define DC_VLC_BITS 9
38#define AC_VLC_BITS 9
39#define OR_VLC_BITS 7
40
41#define DC_VLC_MTD MAX_TABLE_DEPTH(DC_VLC_BITS, MAX_DC_VLC_BITS)
42#define AC_VLC_MTD MAX_TABLE_DEPTH(AC_VLC_BITS, MAX_AC_VLC_BITS)
43#define OR_VLC_MTD MAX_TABLE_DEPTH(OR_VLC_BITS, MAX_OR_VLC_BITS)
44
45static VLC j_ac_vlc[2][2][8];  //[quant<13],[intra/inter],[select]
46static VLC j_dc_vlc[2][8];     //[quant], [select]
47static VLC j_orient_vlc[2][4]; //[quant], [select]
48
49static av_cold void x8_vlc_init(void){
50    int i;
51    int offset = 0;
52    int sizeidx = 0;
53    static const uint16_t sizes[8*4 + 8*2 + 2 + 4] = {
54        576, 548, 582, 618, 546, 616, 560, 642,
55        584, 582, 704, 664, 512, 544, 656, 640,
56        512, 648, 582, 566, 532, 614, 596, 648,
57        586, 552, 584, 590, 544, 578, 584, 624,
58
59        528, 528, 526, 528, 536, 528, 526, 544,
60        544, 512, 512, 528, 528, 544, 512, 544,
61
62        128, 128, 128, 128, 128, 128};
63
64    static VLC_TYPE table[28150][2];
65
66#define  init_ac_vlc(dst,src) \
67    dst.table = &table[offset]; \
68    dst.table_allocated = sizes[sizeidx]; \
69    offset += sizes[sizeidx++]; \
70       init_vlc(&dst, \
71              AC_VLC_BITS,77, \
72              &src[1],4,2, \
73              &src[0],4,2, \
74              INIT_VLC_USE_NEW_STATIC)
75//set ac tables
76    for(i=0;i<8;i++){
77        init_ac_vlc( j_ac_vlc[0][0][i], x8_ac0_highquant_table[i][0] );
78        init_ac_vlc( j_ac_vlc[0][1][i], x8_ac1_highquant_table[i][0] );
79        init_ac_vlc( j_ac_vlc[1][0][i], x8_ac0_lowquant_table [i][0] );
80        init_ac_vlc( j_ac_vlc[1][1][i], x8_ac1_lowquant_table [i][0] );
81    }
82#undef init_ac_vlc
83
84//set dc tables
85#define init_dc_vlc(dst,src) \
86    dst.table = &table[offset]; \
87    dst.table_allocated = sizes[sizeidx]; \
88    offset += sizes[sizeidx++]; \
89        init_vlc(&dst, \
90        DC_VLC_BITS,34, \
91        &src[1],4,2, \
92        &src[0],4,2, \
93        INIT_VLC_USE_NEW_STATIC);
94    for(i=0;i<8;i++){
95        init_dc_vlc( j_dc_vlc[0][i], x8_dc_highquant_table[i][0]);
96        init_dc_vlc( j_dc_vlc[1][i], x8_dc_lowquant_table [i][0]);
97    }
98#undef init_dc_vlc
99
100//set orient tables
101#define init_or_vlc(dst,src) \
102    dst.table = &table[offset]; \
103    dst.table_allocated = sizes[sizeidx]; \
104    offset += sizes[sizeidx++]; \
105    init_vlc(&dst, \
106    OR_VLC_BITS,12, \
107    &src[1],4,2, \
108    &src[0],4,2, \
109    INIT_VLC_USE_NEW_STATIC);
110    for(i=0;i<2;i++){
111        init_or_vlc( j_orient_vlc[0][i], x8_orient_highquant_table[i][0]);
112    }
113    for(i=0;i<4;i++){
114        init_or_vlc( j_orient_vlc[1][i], x8_orient_lowquant_table [i][0])
115    }
116    if (offset != sizeof(table)/sizeof(VLC_TYPE)/2)
117        av_log(NULL, AV_LOG_ERROR, "table size %i does not match needed %i\n", (int)(sizeof(table)/sizeof(VLC_TYPE)/2), offset);
118}
119#undef init_or_vlc
120
121static void x8_reset_vlc_tables(IntraX8Context * w){
122    memset(w->j_dc_vlc,0,sizeof(w->j_dc_vlc));
123    memset(w->j_ac_vlc,0,sizeof(w->j_ac_vlc));
124    w->j_orient_vlc=NULL;
125}
126
127static inline void x8_select_ac_table(IntraX8Context * const w , int mode){
128    MpegEncContext * const s= w->s;
129    int table_index;
130
131    av_assert2(mode<4);
132
133    if( w->j_ac_vlc[mode] ) return;
134
135    table_index = get_bits(&s->gb, 3);
136    w->j_ac_vlc[mode] = &j_ac_vlc[w->quant<13][mode>>1][table_index];//2 modes use same tables
137    av_assert2(w->j_ac_vlc[mode]);
138}
139
140static inline int x8_get_orient_vlc(IntraX8Context * w){
141    MpegEncContext * const s= w->s;
142    int table_index;
143
144    if(!w->j_orient_vlc ){
145        table_index = get_bits(&s->gb, 1+(w->quant<13) );
146        w->j_orient_vlc = &j_orient_vlc[w->quant<13][table_index];
147    }
148
149    return get_vlc2(&s->gb, w->j_orient_vlc->table, OR_VLC_BITS, OR_VLC_MTD);
150}
151
152#define extra_bits(eb) (eb)
153#define extra_run   (0xFF<<8)
154#define extra_level (0x00<<8)
155#define   run_offset(r)    ((r)<<16)
156#define level_offset(l)    ((l)<<24)
157static const uint32_t ac_decode_table[]={
158    /*46*/ extra_bits(3) |  extra_run  | run_offset(16) | level_offset( 0),
159    /*47*/ extra_bits(3) |  extra_run  | run_offset(24) | level_offset( 0),
160    /*48*/ extra_bits(2) |  extra_run  | run_offset( 4) | level_offset( 1),
161    /*49*/ extra_bits(3) |  extra_run  | run_offset( 8) | level_offset( 1),
162
163    /*50*/ extra_bits(5) |  extra_run  | run_offset(32) | level_offset( 0),
164    /*51*/ extra_bits(4) |  extra_run  | run_offset(16) | level_offset( 1),
165
166    /*52*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 4),
167    /*53*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 8),
168    /*54*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset(12),
169    /*55*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset(16),
170    /*56*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset(24),
171
172    /*57*/ extra_bits(2) | extra_level | run_offset( 1) | level_offset( 3),
173    /*58*/ extra_bits(3) | extra_level | run_offset( 1) | level_offset( 7),
174
175    /*59*/ extra_bits(2) |  extra_run  | run_offset(16) | level_offset( 0),
176    /*60*/ extra_bits(2) |  extra_run  | run_offset(20) | level_offset( 0),
177    /*61*/ extra_bits(2) |  extra_run  | run_offset(24) | level_offset( 0),
178    /*62*/ extra_bits(2) |  extra_run  | run_offset(28) | level_offset( 0),
179    /*63*/ extra_bits(4) |  extra_run  | run_offset(32) | level_offset( 0),
180    /*64*/ extra_bits(4) |  extra_run  | run_offset(48) | level_offset( 0),
181
182    /*65*/ extra_bits(2) |  extra_run  | run_offset( 4) | level_offset( 1),
183    /*66*/ extra_bits(3) |  extra_run  | run_offset( 8) | level_offset( 1),
184    /*67*/ extra_bits(4) |  extra_run  | run_offset(16) | level_offset( 1),
185
186    /*68*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 4),
187    /*69*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset( 8),
188    /*70*/ extra_bits(4) | extra_level | run_offset( 0) | level_offset(16),
189
190    /*71*/ extra_bits(2) | extra_level | run_offset( 1) | level_offset( 3),
191    /*72*/ extra_bits(3) | extra_level | run_offset( 1) | level_offset( 7),
192};
193//extra_bits = 3bits; extra_run/level = 1 bit; run_offset = 6bits; level_offset = 5 bits;
194#undef extra_bits
195#undef extra_run
196#undef extra_level
197#undef run_offset
198#undef level_offset
199
200static void x8_get_ac_rlf(IntraX8Context * const w, const int mode,
201                     int * const run, int * const level, int * const final){
202    MpegEncContext *  const s= w->s;
203    int i,e;
204
205//    x8_select_ac_table(w,mode);
206    i = get_vlc2(&s->gb, w->j_ac_vlc[mode]->table, AC_VLC_BITS, AC_VLC_MTD);
207
208    if(i<46){ //[0-45]
209        int t,l;
210        if(i<0){
211            (*level)=(*final)=//prevent 'may be used unilitialized'
212            (*run)=64;//this would cause error exit in the ac loop
213            return;
214        }
215
216        (*final) = t = (i>22);
217        i-=23*t;
218/*
219  i== 0-15 r=0-15 l=0 ;r=i& %01111
220  i==16-19 r=0-3  l=1 ;r=i& %00011
221  i==20-21 r=0-1  l=2 ;r=i& %00001
222  i==22    r=0    l=3 ;r=i& %00000
223l=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
224t=lut_mask[l]={0x0f,0x03,0x01,0x00}[l]; as i<256 the higher bits do not matter */
225        l=(0xE50000>>(i&(0x1E)))&3;/*0x1E or (~1) or ((i>>1)<<1)*/
226        t=(0x01030F>>(l<<3));
227
228        (*run)   = i&t;
229        (*level) = l;
230    }else if(i<73){//[46-72]
231        uint32_t sm;
232        uint32_t mask;
233
234        i-=46;
235        sm=ac_decode_table[i];
236
237        e=get_bits(&s->gb,sm&0xF);sm>>=8;//3bits
238        mask=sm&0xff;sm>>=8;             //1bit
239
240        (*run)  =(sm&0xff) + (e&( mask));//6bits
241        (*level)=(sm>>8)   + (e&(~mask));//5bits
242        (*final)=i>(58-46);
243    }else if(i<75){//[73-74]
244        static const uint8_t crazy_mix_runlevel[32]={
245        0x22,0x32,0x33,0x53,0x23,0x42,0x43,0x63,
246        0x24,0x52,0x34,0x73,0x25,0x62,0x44,0x83,
247        0x26,0x72,0x35,0x54,0x27,0x82,0x45,0x64,
248        0x28,0x92,0x36,0x74,0x29,0xa2,0x46,0x84};
249
250        (*final)=!(i&1);
251        e=get_bits(&s->gb,5);//get the extra bits
252        (*run)  =crazy_mix_runlevel[e]>>4;
253        (*level)=crazy_mix_runlevel[e]&0x0F;
254    }else{
255        (*level)=get_bits( &s->gb, 7-3*(i&1));
256        (*run)  =get_bits( &s->gb, 6);
257        (*final)=get_bits1(&s->gb);
258    }
259    return;
260}
261
262//static const uint8_t dc_extra_sbits[]   ={0, 1,1, 1,1, 2,2, 3,3,   4,4,   5,5,   6,6,    7,7    };
263static const uint8_t dc_index_offset[]  ={ 0, 1,2, 3,4, 5,7, 9,13, 17,25, 33,49, 65,97, 129,193};
264
265static int x8_get_dc_rlf(IntraX8Context * const w,int const mode, int * const level, int * const final){
266    MpegEncContext * const s= w->s;
267    int i,e,c;
268
269    av_assert2(mode<3);
270    if( !w->j_dc_vlc[mode] ) {
271        int table_index;
272        table_index = get_bits(&s->gb, 3);
273        //4 modes, same table
274        w->j_dc_vlc[mode]= &j_dc_vlc[w->quant<13][table_index];
275    }
276
277    i=get_vlc2(&s->gb, w->j_dc_vlc[mode]->table, DC_VLC_BITS, DC_VLC_MTD);
278
279    /*(i>=17) {i-=17;final=1;}*/
280    c= i>16;
281    (*final)=c;
282    i-=17*c;
283
284    if(i<=0){
285        (*level)=0;
286        return -i;
287    }
288    c=(i+1)>>1;//hackish way to calculate dc_extra_sbits[]
289    c-=c>1;
290
291    e=get_bits(&s->gb,c);//get the extra bits
292    i=dc_index_offset[i]+(e>>1);
293
294    e= -(e & 1);//0,0xffffff
295    (*level)= (i ^ e) - e;// (i^0)-0 , (i^0xff)-(-1)
296    return 0;
297}
298//end of huffman
299
300static int x8_setup_spatial_predictor(IntraX8Context * const w, const int chroma){
301    MpegEncContext * const s= w->s;
302    int range;
303    int sum;
304    int quant;
305
306    w->dsp.setup_spatial_compensation(s->dest[chroma], s->edge_emu_buffer,
307                                      s->current_picture.f->linesize[chroma>0],
308                                      &range, &sum, w->edges);
309    if(chroma){
310        w->orient=w->chroma_orient;
311        quant=w->quant_dc_chroma;
312    }else{
313        quant=w->quant;
314    }
315
316    w->flat_dc=0;
317    if(range < quant || range < 3){
318        w->orient=0;
319        if(range < 3){//yep you read right, a +-1 idct error may break decoding!
320            w->flat_dc=1;
321            sum+=9;
322            w->predicted_dc = (sum*6899)>>17;//((1<<17)+9)/(8+8+1+2)=6899
323        }
324    }
325    if(chroma)
326        return 0;
327
328    av_assert2(w->orient < 3);
329    if(range < 2*w->quant){
330        if( (w->edges&3) == 0){
331            if(w->orient==1) w->orient=11;
332            if(w->orient==2) w->orient=10;
333        }else{
334            w->orient=0;
335        }
336        w->raw_orient=0;
337    }else{
338        static const uint8_t prediction_table[3][12]={
339            {0,8,4, 10,11, 2,6,9,1,3,5,7},
340            {4,0,8, 11,10, 3,5,2,6,9,1,7},
341            {8,0,4, 10,11, 1,7,2,6,9,3,5}
342        };
343        w->raw_orient=x8_get_orient_vlc(w);
344        if(w->raw_orient<0) return -1;
345        av_assert2(w->raw_orient < 12 );
346        av_assert2(w->orient<3);
347        w->orient=prediction_table[w->orient][w->raw_orient];
348    }
349    return 0;
350}
351
352static void x8_update_predictions(IntraX8Context * const w, const int orient, const int est_run ){
353    MpegEncContext * const s= w->s;
354
355    w->prediction_table[s->mb_x*2+(s->mb_y&1)] = (est_run<<2) + 1*(orient==4) + 2*(orient==8);
356/*
357  y=2n+0 ->//0 2 4
358  y=2n+1 ->//1 3 5
359*/
360}
361static void x8_get_prediction_chroma(IntraX8Context * const w){
362    MpegEncContext * const s= w->s;
363
364    w->edges = 1*( !(s->mb_x>>1) );
365    w->edges|= 2*( !(s->mb_y>>1) );
366    w->edges|= 4*( s->mb_x >= (2*s->mb_width-1) );//mb_x for chroma would always be odd
367
368    w->raw_orient=0;
369    if(w->edges&3){//lut_co[8]={inv,4,8,8, inv,4,8,8}<- =>{1,1,0,0;1,1,0,0} => 0xCC
370        w->chroma_orient=4<<((0xCC>>w->edges)&1);
371        return;
372    }
373    w->chroma_orient = (w->prediction_table[2*s->mb_x-2] & 0x03)<<2;//block[x-1][y|1-1)]
374}
375
376static void x8_get_prediction(IntraX8Context * const w){
377    MpegEncContext * const s= w->s;
378    int a,b,c,i;
379
380    w->edges = 1*( !s->mb_x );
381    w->edges|= 2*( !s->mb_y );
382    w->edges|= 4*( s->mb_x >= (2*s->mb_width-1) );
383
384    switch(w->edges&3){
385        case 0:
386            break;
387        case 1:
388            //take the one from the above block[0][y-1]
389            w->est_run = w->prediction_table[!(s->mb_y&1)]>>2;
390            w->orient  = 1;
391            return;
392        case 2:
393            //take the one from the previous block[x-1][0]
394            w->est_run = w->prediction_table[2*s->mb_x-2]>>2;
395            w->orient  = 2;
396            return;
397        case 3:
398            w->est_run = 16;
399            w->orient  = 0;
400            return;
401    }
402    //no edge cases
403    b= w->prediction_table[2*s->mb_x   + !(s->mb_y&1) ];//block[x  ][y-1]
404    a= w->prediction_table[2*s->mb_x-2 +  (s->mb_y&1) ];//block[x-1][y  ]
405    c= w->prediction_table[2*s->mb_x-2 + !(s->mb_y&1) ];//block[x-1][y-1]
406
407    w->est_run = FFMIN(b,a);
408    /* This condition has nothing to do with w->edges, even if it looks
409       similar it would trigger if e.g. x=3;y=2;
410       I guess somebody wrote something wrong and it became standard. */
411    if( (s->mb_x & s->mb_y) != 0 ) w->est_run=FFMIN(c,w->est_run);
412    w->est_run>>=2;
413
414    a&=3;
415    b&=3;
416    c&=3;
417
418    i=( 0xFFEAF4C4>>(2*b+8*a) )&3;
419    if(i!=3) w->orient=i;
420    else     w->orient=( 0xFFEAD8>>(2*c+8*(w->quant>12)) )&3;
421/*
422lut1[b][a]={
423->{0, 1, 0, pad},
424  {0, 1, X, pad},
425  {2, 2, 2, pad}}
426   pad 2   2  2; pad X  1  0; pad 0  1  0 <-
427-> 11 10 '10 10 '11 11'01 00 '11 00'01 00=>0xEAF4C4
428
429lut2[q>12][c]={
430  ->{0,2,1,pad},
431    {2,2,2,pad}}
432   pad 2  2  2; pad 1  2  0 <-
433-> 11 10'10 10 '11 01'10 00=>0xEAD8
434*/
435}
436
437
438static void x8_ac_compensation(IntraX8Context * const w, int const direction, int const dc_level){
439    MpegEncContext * const s= w->s;
440    int t;
441#define B(x,y)  s->block[0][w->idct_permutation[(x)+(y)*8]]
442#define T(x)  ((x) * dc_level + 0x8000) >> 16;
443    switch(direction){
444    case 0:
445        t = T(3811);//h
446        B(1,0) -= t;
447        B(0,1) -= t;
448
449        t = T(487);//e
450        B(2,0) -= t;
451        B(0,2) -= t;
452
453        t = T(506);//f
454        B(3,0) -= t;
455        B(0,3) -= t;
456
457        t = T(135);//c
458        B(4,0) -= t;
459        B(0,4) -= t;
460        B(2,1) += t;
461        B(1,2) += t;
462        B(3,1) += t;
463        B(1,3) += t;
464
465        t = T(173);//d
466        B(5,0) -= t;
467        B(0,5) -= t;
468
469        t = T(61);//b
470        B(6,0) -= t;
471        B(0,6) -= t;
472        B(5,1) += t;
473        B(1,5) += t;
474
475        t = T(42); //a
476        B(7,0) -= t;
477        B(0,7) -= t;
478        B(4,1) += t;
479        B(1,4) += t;
480        B(4,4) += t;
481
482        t = T(1084);//g
483        B(1,1) += t;
484
485        s->block_last_index[0] = FFMAX(s->block_last_index[0], 7*8);
486        break;
487    case 1:
488        B(0,1) -= T(6269);
489        B(0,3) -= T( 708);
490        B(0,5) -= T( 172);
491        B(0,7) -= T(  73);
492
493        s->block_last_index[0] = FFMAX(s->block_last_index[0], 7*8);
494        break;
495    case 2:
496        B(1,0) -= T(6269);
497        B(3,0) -= T( 708);
498        B(5,0) -= T( 172);
499        B(7,0) -= T(  73);
500
501        s->block_last_index[0] = FFMAX(s->block_last_index[0], 7);
502        break;
503    }
504#undef B
505#undef T
506}
507
508static void dsp_x8_put_solidcolor(uint8_t const pix, uint8_t * dst, int const linesize){
509    int k;
510    for(k=0;k<8;k++){
511        memset(dst,pix,8);
512        dst+=linesize;
513    }
514}
515
516static const int16_t quant_table[64] = {
517    256, 256, 256, 256,  256, 256, 259, 262,
518    265, 269, 272, 275,  278, 282, 285, 288,
519    292, 295, 299, 303,  306, 310, 314, 317,
520    321, 325, 329, 333,  337, 341, 345, 349,
521    353, 358, 362, 366,  371, 375, 379, 384,
522    389, 393, 398, 403,  408, 413, 417, 422,
523    428, 433, 438, 443,  448, 454, 459, 465,
524    470, 476, 482, 488,  493, 499, 505, 511
525};
526
527static int x8_decode_intra_mb(IntraX8Context* const w, const int chroma){
528    MpegEncContext * const s= w->s;
529
530    uint8_t * scantable;
531    int final,run,level;
532    int ac_mode,dc_mode,est_run,dc_level;
533    int pos,n;
534    int zeros_only;
535    int use_quant_matrix;
536    int sign;
537
538    av_assert2(w->orient<12);
539    s->bdsp.clear_block(s->block[0]);
540
541    if(chroma){
542        dc_mode=2;
543    }else{
544        dc_mode=!!w->est_run;//0,1
545    }
546
547    if(x8_get_dc_rlf(w, dc_mode, &dc_level, &final)) return -1;
548    n=0;
549    zeros_only=0;
550    if(!final){//decode ac
551        use_quant_matrix=w->use_quant_matrix;
552        if(chroma){
553            ac_mode = 1;
554            est_run = 64;//not used
555        }else{
556            if (w->raw_orient < 3){
557                use_quant_matrix = 0;
558            }
559            if(w->raw_orient > 4){
560                ac_mode = 0;
561                est_run = 64;
562            }else{
563                if(w->est_run > 1){
564                    ac_mode = 2;
565                    est_run=w->est_run;
566                }else{
567                    ac_mode = 3;
568                    est_run = 64;
569                }
570            }
571        }
572        x8_select_ac_table(w,ac_mode);
573        /*scantable_selector[12]={0,2,0,1,1,1,0,2,2,0,1,2};<-
574        -> 10'01' 00'10' 10'00' 01'01' 01'00' 10'00 =>0x928548 */
575        scantable = w->scantable[ (0x928548>>(2*w->orient))&3 ].permutated;
576        pos=0;
577        do {
578            n++;
579            if( n >= est_run ){
580                ac_mode=3;
581                x8_select_ac_table(w,3);
582            }
583
584            x8_get_ac_rlf(w,ac_mode,&run,&level,&final);
585
586            pos+=run+1;
587            if(pos>63){
588                //this also handles vlc error in x8_get_ac_rlf
589                return -1;
590            }
591            level= (level+1) * w->dquant;
592            level+= w->qsum;
593
594            sign = - get_bits1(&s->gb);
595            level = (level ^ sign) - sign;
596
597            if(use_quant_matrix){
598                level = (level*quant_table[pos])>>8;
599            }
600            s->block[0][ scantable[pos] ]=level;
601        }while(!final);
602
603        s->block_last_index[0]=pos;
604    }else{//DC only
605        s->block_last_index[0]=0;
606        if(w->flat_dc && ((unsigned)(dc_level+1)) < 3){//[-1;1]
607            int32_t divide_quant= !chroma ? w->divide_quant_dc_luma:
608                                            w->divide_quant_dc_chroma;
609            int32_t dc_quant    = !chroma ? w->quant:
610                                            w->quant_dc_chroma;
611
612            //original intent dc_level+=predicted_dc/quant; but it got lost somewhere in the rounding
613            dc_level+= (w->predicted_dc*divide_quant + (1<<12) )>>13;
614
615            dsp_x8_put_solidcolor( av_clip_uint8((dc_level*dc_quant+4)>>3),
616                                   s->dest[chroma], s->current_picture.f->linesize[!!chroma]);
617
618            goto block_placed;
619        }
620        zeros_only = (dc_level == 0);
621    }
622    if(!chroma){
623        s->block[0][0] = dc_level*w->quant;
624    }else{
625        s->block[0][0] = dc_level*w->quant_dc_chroma;
626    }
627
628    //there is !zero_only check in the original, but dc_level check is enough
629    if( (unsigned int)(dc_level+1) >= 3 && (w->edges&3) != 3 ){
630        int direction;
631        /*ac_comp_direction[orient] = { 0, 3, 3, 1, 1, 0, 0, 0, 2, 2, 2, 1 };<-
632        -> 01'10' 10'10' 00'00' 00'01' 01'11' 11'00 =>0x6A017C */
633        direction= (0x6A017C>>(w->orient*2))&3;
634        if (direction != 3){
635            x8_ac_compensation(w, direction, s->block[0][0]);//modify block_last[]
636        }
637    }
638
639    if(w->flat_dc){
640        dsp_x8_put_solidcolor(w->predicted_dc, s->dest[chroma], s->current_picture.f->linesize[!!chroma]);
641    }else{
642        w->dsp.spatial_compensation[w->orient]( s->edge_emu_buffer,
643                                            s->dest[chroma],
644                                            s->current_picture.f->linesize[!!chroma] );
645    }
646    if(!zeros_only)
647        w->wdsp.idct_add(s->dest[chroma],
648                         s->current_picture.f->linesize[!!chroma],
649                         s->block[0]);
650
651block_placed:
652
653    if(!chroma){
654        x8_update_predictions(w,w->orient,n);
655    }
656
657    if(s->loop_filter){
658        uint8_t* ptr = s->dest[chroma];
659        int linesize = s->current_picture.f->linesize[!!chroma];
660
661        if(!( (w->edges&2) || ( zeros_only && (w->orient|4)==4 ) )){
662            w->dsp.h_loop_filter(ptr, linesize, w->quant);
663        }
664        if(!( (w->edges&1) || ( zeros_only && (w->orient|8)==8 ) )){
665            w->dsp.v_loop_filter(ptr, linesize, w->quant);
666        }
667    }
668    return 0;
669}
670
671static void x8_init_block_index(MpegEncContext *s){ //FIXME maybe merge with ff_*
672//not s->linesize as this would be wrong for field pics
673//not that IntraX8 has interlacing support ;)
674    const int linesize   = s->current_picture.f->linesize[0];
675    const int uvlinesize = s->current_picture.f->linesize[1];
676
677    s->dest[0] = s->current_picture.f->data[0];
678    s->dest[1] = s->current_picture.f->data[1];
679    s->dest[2] = s->current_picture.f->data[2];
680
681    s->dest[0] +=   s->mb_y        *   linesize << 3;
682    s->dest[1] += ( s->mb_y&(~1) ) * uvlinesize << 2;//chroma blocks are on add rows
683    s->dest[2] += ( s->mb_y&(~1) ) * uvlinesize << 2;
684}
685
686/**
687 * Initialize IntraX8 frame decoder.
688 * Requires valid MpegEncContext with valid s->mb_width before calling.
689 * @param w pointer to IntraX8Context
690 * @param s pointer to MpegEncContext of the parent codec
691 */
692av_cold void ff_intrax8_common_init(IntraX8Context * w, MpegEncContext * const s){
693
694    w->s=s;
695    x8_vlc_init();
696    av_assert0(s->mb_width>0);
697    w->prediction_table=av_mallocz(s->mb_width*2*2);//two rows, 2 blocks per cannon mb
698
699    ff_wmv2dsp_init(&w->wdsp);
700    ff_init_scantable_permutation(w->idct_permutation,
701                                  w->wdsp.idct_perm);
702
703    ff_init_scantable(w->idct_permutation, &w->scantable[0], ff_wmv1_scantable[0]);
704    ff_init_scantable(w->idct_permutation, &w->scantable[1], ff_wmv1_scantable[2]);
705    ff_init_scantable(w->idct_permutation, &w->scantable[2], ff_wmv1_scantable[3]);
706
707    ff_intrax8dsp_init(&w->dsp);
708}
709
710/**
711 * Destroy IntraX8 frame structure.
712 * @param w pointer to IntraX8Context
713 */
714av_cold void ff_intrax8_common_end(IntraX8Context * w)
715{
716    av_freep(&w->prediction_table);
717}
718
719/**
720 * Decode single IntraX8 frame.
721 * The parent codec must fill s->loopfilter and s->gb (bitstream).
722 * The parent codec must call MPV_frame_start(), ff_er_frame_start() before calling this function.
723 * The parent codec must call ff_er_frame_end(), MPV_frame_end() after calling this function.
724 * This function does not use MPV_decode_mb().
725 * lowres decoding is theoretically impossible.
726 * @param w pointer to IntraX8Context
727 * @param dquant doubled quantizer, it would be odd in case of VC-1 halfpq==1.
728 * @param quant_offset offset away from zero
729 */
730int ff_intrax8_decode_picture(IntraX8Context * const w, int dquant, int quant_offset){
731    MpegEncContext * const s= w->s;
732    int mb_xy;
733    w->use_quant_matrix = get_bits1(&s->gb);
734
735    w->dquant = dquant;
736    w->quant  = dquant >> 1;
737    w->qsum   = quant_offset;
738
739    w->divide_quant_dc_luma = ((1<<16) + (w->quant>>1)) / w->quant;
740    if(w->quant < 5){
741        w->quant_dc_chroma =  w->quant;
742        w->divide_quant_dc_chroma = w->divide_quant_dc_luma;
743    }else{
744        w->quant_dc_chroma =  w->quant+((w->quant+3)>>3);
745        w->divide_quant_dc_chroma = ((1<<16) + (w->quant_dc_chroma>>1)) / w->quant_dc_chroma;
746    }
747    x8_reset_vlc_tables(w);
748
749    s->resync_mb_x=0;
750    s->resync_mb_y=0;
751
752    for(s->mb_y=0; s->mb_y < s->mb_height*2; s->mb_y++){
753        x8_init_block_index(s);
754        mb_xy=(s->mb_y>>1)*s->mb_stride;
755
756        for(s->mb_x=0; s->mb_x < s->mb_width*2; s->mb_x++){
757            x8_get_prediction(w);
758            if(x8_setup_spatial_predictor(w,0)) goto error;
759            if(x8_decode_intra_mb(w,0)) goto error;
760
761            if( s->mb_x & s->mb_y & 1 ){
762                x8_get_prediction_chroma(w);
763
764                /*when setting up chroma, no vlc is read,
765                so no error condition can be reached*/
766                x8_setup_spatial_predictor(w,1);
767                if(x8_decode_intra_mb(w,1)) goto error;
768
769                x8_setup_spatial_predictor(w,2);
770                if(x8_decode_intra_mb(w,2)) goto error;
771
772                s->dest[1]+= 8;
773                s->dest[2]+= 8;
774
775                /*emulate MB info in the relevant tables*/
776                s->mbskip_table [mb_xy]=0;
777                s->mbintra_table[mb_xy]=1;
778                s->current_picture.qscale_table[mb_xy] = w->quant;
779                mb_xy++;
780            }
781            s->dest[0]+= 8;
782        }
783        if(s->mb_y&1){
784            ff_mpeg_draw_horiz_band(s, (s->mb_y-1)*8, 16);
785        }
786    }
787
788error:
789    ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
790                        (s->mb_x>>1)-1, (s->mb_y>>1)-1,
791                        ER_MB_END );
792    return 0;
793}
794