per context frame_rate_base, this should finally fix frame_rate related av sync issues
[ffmpeg.git] / libavcodec / msmpeg4.c
1 /*
2  * MSMPEG4 backend for ffmpeg encoder and decoder
3  * Copyright (c) 2001 Fabrice Bellard.
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this library; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  *
19  * msmpeg4v1 & v2 stuff by Michael Niedermayer <michaelni@gmx.at>
20  */
21
22 /**
23  * @file msmpeg4.c
24  * MSMPEG4 backend for ffmpeg encoder and decoder.
25  */
26
27 #include "avcodec.h"
28 #include "dsputil.h"
29 #include "mpegvideo.h"
30 //#define PRINT_MB
31
32 /*
33  * You can also call this codec : MPEG4 with a twist ! 
34  *
35  * TODO: 
36  *        - (encoding) select best mv table (two choices)
37  *        - (encoding) select best vlc/dc table 
38  */
39 //#define DEBUG
40
41 #define DC_VLC_BITS 9
42 #define CBPY_VLC_BITS 6
43 #define INTER_INTRA_VLC_BITS 3
44 #define V1_INTRA_CBPC_VLC_BITS 6
45 #define V1_INTER_CBPC_VLC_BITS 6
46 #define V2_INTRA_CBPC_VLC_BITS 3
47 #define V2_MB_TYPE_VLC_BITS 7
48 #define MV_VLC_BITS 9
49 #define V2_MV_VLC_BITS 9
50 #define TEX_VLC_BITS 9
51 #define MB_NON_INTRA_VLC_BITS 9
52 #define MB_INTRA_VLC_BITS 9
53
54 #define II_BITRATE 128*1024
55 #define MBAC_BITRATE 50*1024
56
57 #define DEFAULT_INTER_INDEX 3
58
59 static uint32_t v2_dc_lum_table[512][2];
60 static uint32_t v2_dc_chroma_table[512][2];
61
62 #ifdef CONFIG_ENCODERS
63 static inline void msmpeg4_encode_block(MpegEncContext * s, DCTELEM * block, int n);
64 #endif //CONFIG_ENCODERS
65 static inline int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
66                                        int n, int coded, const uint8_t *scantable);
67 static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr);
68 static int msmpeg4_decode_motion(MpegEncContext * s, 
69                                  int *mx_ptr, int *my_ptr);
70 #ifdef CONFIG_ENCODERS
71 static void msmpeg4v2_encode_motion(MpegEncContext * s, int val);
72 #endif //CONFIG_ENCODERS
73 static void init_h263_dc_for_msmpeg4(void);
74 static inline void msmpeg4_memsetw(short *tab, int val, int n);
75 #ifdef CONFIG_ENCODERS
76 static int get_size_of_code(MpegEncContext * s, RLTable *rl, int last, int run, int level, int intra);
77 #endif //CONFIG_ENCODERS
78 static int msmpeg4v12_decode_mb(MpegEncContext *s, DCTELEM block[6][64]);
79 static int msmpeg4v34_decode_mb(MpegEncContext *s, DCTELEM block[6][64]);
80 static int wmv2_decode_mb(MpegEncContext *s, DCTELEM block[6][64]);
81
82 extern uint32_t inverse[256];
83
84
85 #ifdef DEBUG
86 int intra_count = 0;
87 int frame_count = 0;
88 #endif
89
90 #include "msmpeg4data.h"
91
92 static uint8_t rl_length[NB_RL_TABLES][MAX_LEVEL+1][MAX_RUN+1][2];
93
94 #ifdef STATS
95
96 const char *st_names[ST_NB] = {
97     "unknown",
98     "dc",
99     "intra_ac",
100     "inter_ac",
101     "intra_mb",
102     "inter_mb",
103     "mv",
104 };
105
106 int st_current_index = 0;
107 unsigned int st_bit_counts[ST_NB];
108 unsigned int st_out_bit_counts[ST_NB];
109
110 #define set_stat(var) st_current_index = var;
111
112 void print_stats(void)
113 {
114     unsigned int total;
115     int i;
116
117     printf("Input:\n");
118     total = 0;
119     for(i=0;i<ST_NB;i++)
120         total += st_bit_counts[i];
121     if (total == 0)
122         total = 1;
123     for(i=0;i<ST_NB;i++) {
124         printf("%-10s : %10.1f %5.1f%%\n", 
125                st_names[i], 
126                (double)st_bit_counts[i] / 8.0, 
127                (double)st_bit_counts[i] * 100.0 / total);
128     }
129     printf("%-10s : %10.1f %5.1f%%\n",
130            "total", 
131            (double)total / 8.0, 
132            100.0);
133
134     printf("Output:\n");
135     total = 0;
136     for(i=0;i<ST_NB;i++)
137         total += st_out_bit_counts[i];
138     if (total == 0)
139         total = 1;
140     for(i=0;i<ST_NB;i++) {
141         printf("%-10s : %10.1f %5.1f%%\n", 
142                st_names[i], 
143                (double)st_out_bit_counts[i] / 8.0, 
144                (double)st_out_bit_counts[i] * 100.0 / total);
145     }
146     printf("%-10s : %10.1f %5.1f%%\n",
147            "total", 
148            (double)total / 8.0, 
149            100.0);
150 }
151
152 #else
153
154 #define set_stat(var)
155
156 #endif
157
158 static void common_init(MpegEncContext * s)
159 {
160     static int inited=0;
161     
162     switch(s->msmpeg4_version){
163     case 1:
164     case 2:
165         s->y_dc_scale_table=
166         s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
167         break;
168     case 3:
169         if(s->workaround_bugs){
170             s->y_dc_scale_table= old_ff_y_dc_scale_table;
171             s->c_dc_scale_table= old_ff_c_dc_scale_table;
172         } else{
173             s->y_dc_scale_table= ff_mpeg4_y_dc_scale_table;
174             s->c_dc_scale_table= ff_mpeg4_c_dc_scale_table;
175         }
176         break;
177     case 4:
178     case 5:
179         s->y_dc_scale_table= wmv1_y_dc_scale_table;
180         s->c_dc_scale_table= wmv1_c_dc_scale_table;
181         break;
182     }
183
184     
185     if(s->msmpeg4_version>=4){
186         ff_init_scantable(s, &s->intra_scantable  , wmv1_scantable[1]);
187         ff_init_scantable(s, &s->intra_h_scantable, wmv1_scantable[2]);
188         ff_init_scantable(s, &s->intra_v_scantable, wmv1_scantable[3]);
189         ff_init_scantable(s, &s->inter_scantable  , wmv1_scantable[0]);
190     }
191     //Note the default tables are set in common_init in mpegvideo.c
192     
193     if(!inited){
194         inited=1;
195
196         init_h263_dc_for_msmpeg4();
197     }
198 }
199
200 #ifdef CONFIG_ENCODERS
201
202 /* build the table which associate a (x,y) motion vector to a vlc */
203 static void init_mv_table(MVTable *tab)
204 {
205     int i, x, y;
206
207     tab->table_mv_index = av_malloc(sizeof(uint16_t) * 4096);
208     /* mark all entries as not used */
209     for(i=0;i<4096;i++)
210         tab->table_mv_index[i] = tab->n;
211     
212     for(i=0;i<tab->n;i++) {
213         x = tab->table_mvx[i];
214         y = tab->table_mvy[i];
215         tab->table_mv_index[(x << 6) | y] = i;
216     }
217 }
218
219 static void code012(PutBitContext *pb, int n)
220 {
221     if (n == 0) {
222         put_bits(pb, 1, 0);
223     } else {
224         put_bits(pb, 1, 1);
225         put_bits(pb, 1, (n >= 2));
226     }
227 }
228
229 void ff_msmpeg4_encode_init(MpegEncContext *s)
230 {
231     static int init_done=0;
232     int i;
233
234     common_init(s);
235     if(s->msmpeg4_version>=4){
236         s->min_qcoeff= -255;
237         s->max_qcoeff=  255;
238     }
239
240     if (!init_done) {
241         /* init various encoding tables */
242         init_done = 1;
243         init_mv_table(&mv_tables[0]);
244         init_mv_table(&mv_tables[1]);
245         for(i=0;i<NB_RL_TABLES;i++)
246             init_rl(&rl_table[i]);
247
248         for(i=0; i<NB_RL_TABLES; i++){
249             int level;
250             for(level=0; level<=MAX_LEVEL; level++){
251                 int run;
252                 for(run=0; run<=MAX_RUN; run++){
253                     int last;
254                     for(last=0; last<2; last++){
255                         rl_length[i][level][run][last]= get_size_of_code(s, &rl_table[  i], last, run, level, 0);
256                     }
257                 }
258             }
259         }
260     }
261 }
262
263 static int get_size_of_code(MpegEncContext * s, RLTable *rl, int last, int run, int level, int intra){
264     int size=0;
265     int code;
266     int run_diff= intra ? 0 : 1;
267     
268     code = get_rl_index(rl, last, run, level);
269     size+= rl->table_vlc[code][1];
270     if (code == rl->n) {
271         int level1, run1;
272
273         level1 = level - rl->max_level[last][run];
274         if (level1 < 1) 
275             goto esc2;
276         code = get_rl_index(rl, last, run, level1);
277         if (code == rl->n) {
278             esc2:
279             size++;
280             if (level > MAX_LEVEL)
281                 goto esc3;
282             run1 = run - rl->max_run[last][level] - run_diff;
283             if (run1 < 0)
284                 goto esc3;
285             code = get_rl_index(rl, last, run1, level);
286             if (code == rl->n) {
287             esc3:
288                 /* third escape */
289                 size+=1+1+6+8;
290             } else {
291                 /* second escape */
292                 size+= 1+1+ rl->table_vlc[code][1];
293             }
294         } else {
295             /* first escape */
296             size+= 1+1+ rl->table_vlc[code][1];
297         }
298     } else {
299         size++;
300     }
301     return size;
302 }
303
304 static void find_best_tables(MpegEncContext * s)
305 {
306     int i;
307     int best       =-1, best_size       =9999999;
308     int chroma_best=-1, best_chroma_size=9999999;
309
310     for(i=0; i<3; i++){
311         int level;
312         int chroma_size=0;
313         int size=0;
314
315         if(i>0){// ;)
316             size++; 
317             chroma_size++;
318         }
319         for(level=0; level<=MAX_LEVEL; level++){
320             int run;
321             for(run=0; run<=MAX_RUN; run++){
322                 int last;
323                 const int last_size= size + chroma_size;
324                 for(last=0; last<2; last++){
325                     int inter_count       = s->ac_stats[0][0][level][run][last] + s->ac_stats[0][1][level][run][last];
326                     int intra_luma_count  = s->ac_stats[1][0][level][run][last];
327                     int intra_chroma_count= s->ac_stats[1][1][level][run][last];
328                     
329                     if(s->pict_type==I_TYPE){
330                         size       += intra_luma_count  *rl_length[i  ][level][run][last];
331                         chroma_size+= intra_chroma_count*rl_length[i+3][level][run][last];
332                     }else{
333                         size+=        intra_luma_count  *rl_length[i  ][level][run][last]
334                                      +intra_chroma_count*rl_length[i+3][level][run][last]
335                                      +inter_count       *rl_length[i+3][level][run][last];
336                     }                   
337                 }
338                 if(last_size == size+chroma_size) break;
339             }
340         }
341         if(size<best_size){
342             best_size= size;
343             best= i;
344         }
345         if(chroma_size<best_chroma_size){
346             best_chroma_size= chroma_size;
347             chroma_best= i;
348         }
349     }
350
351 //    printf("type:%d, best:%d, qp:%d, var:%d, mcvar:%d, size:%d //\n", 
352 //           s->pict_type, best, s->qscale, s->mb_var_sum, s->mc_mb_var_sum, best_size);
353            
354     if(s->pict_type==P_TYPE) chroma_best= best;
355
356     memset(s->ac_stats, 0, sizeof(int)*(MAX_LEVEL+1)*(MAX_RUN+1)*2*2*2);
357
358     s->rl_table_index       =        best;
359     s->rl_chroma_table_index= chroma_best;
360     
361     if(s->pict_type != s->last_non_b_pict_type){
362         s->rl_table_index= 2;
363         if(s->pict_type==I_TYPE)
364             s->rl_chroma_table_index= 1;
365         else
366             s->rl_chroma_table_index= 2;
367     }
368
369 }
370
371 /* write MSMPEG4 compatible frame header */
372 void msmpeg4_encode_picture_header(MpegEncContext * s, int picture_number)
373 {
374     find_best_tables(s);
375
376     align_put_bits(&s->pb);
377     put_bits(&s->pb, 2, s->pict_type - 1);
378
379     put_bits(&s->pb, 5, s->qscale);
380     if(s->msmpeg4_version<=2){
381         s->rl_table_index = 2;
382         s->rl_chroma_table_index = 2;
383     }
384
385     s->dc_table_index = 1;
386     s->mv_table_index = 1; /* only if P frame */
387     s->use_skip_mb_code = 1; /* only if P frame */
388     s->per_mb_rl_table = 0;
389     if(s->msmpeg4_version==4)
390         s->inter_intra_pred= (s->width*s->height < 320*240 && s->bit_rate<=II_BITRATE && s->pict_type==P_TYPE);
391 //printf("%d %d %d %d %d\n", s->pict_type, s->bit_rate, s->inter_intra_pred, s->width, s->height);
392
393     if (s->pict_type == I_TYPE) {
394         s->slice_height= s->mb_height/1;
395         put_bits(&s->pb, 5, 0x16 + s->mb_height/s->slice_height);
396         
397         if(s->msmpeg4_version==4){
398             msmpeg4_encode_ext_header(s);
399             if(s->bit_rate>MBAC_BITRATE)
400                 put_bits(&s->pb, 1, s->per_mb_rl_table);
401         }
402
403         if(s->msmpeg4_version>2){
404             if(!s->per_mb_rl_table){
405                 code012(&s->pb, s->rl_chroma_table_index);
406                 code012(&s->pb, s->rl_table_index);
407             }
408
409             put_bits(&s->pb, 1, s->dc_table_index);
410         }
411     } else {
412         put_bits(&s->pb, 1, s->use_skip_mb_code);
413         
414         if(s->msmpeg4_version==4 && s->bit_rate>MBAC_BITRATE)
415             put_bits(&s->pb, 1, s->per_mb_rl_table);
416
417         if(s->msmpeg4_version>2){
418             if(!s->per_mb_rl_table)
419                 code012(&s->pb, s->rl_table_index);
420
421             put_bits(&s->pb, 1, s->dc_table_index);
422
423             put_bits(&s->pb, 1, s->mv_table_index);
424         }
425     }
426
427     s->esc3_level_length= 0;
428     s->esc3_run_length= 0;
429
430 #ifdef DEBUG
431     intra_count = 0;
432     printf("*****frame %d:\n", frame_count++);
433 #endif
434 }
435
436 void msmpeg4_encode_ext_header(MpegEncContext * s)
437 {
438         put_bits(&s->pb, 5, s->avctx->frame_rate / s->avctx->frame_rate_base); //yes 29.97 -> 29
439
440         put_bits(&s->pb, 11, FFMIN(s->bit_rate/1024, 2047));
441
442         if(s->msmpeg4_version<3)
443             s->flipflop_rounding=0;
444         else{
445             s->flipflop_rounding=1;
446             put_bits(&s->pb, 1, s->flipflop_rounding);
447         }
448 }
449
450 #endif //CONFIG_ENCODERS
451
452 /* predict coded block */
453 static inline int coded_block_pred(MpegEncContext * s, int n, uint8_t **coded_block_ptr)
454 {
455     int xy, wrap, pred, a, b, c;
456
457     xy = s->block_index[n];
458     wrap = s->block_wrap[0];
459
460     /* B C
461      * A X 
462      */
463     a = s->coded_block[xy - 1       ];
464     b = s->coded_block[xy - 1 - wrap];
465     c = s->coded_block[xy     - wrap];
466     
467     if (b == c) {
468         pred = a;
469     } else {
470         pred = c;
471     }
472     
473     /* store value */
474     *coded_block_ptr = &s->coded_block[xy];
475
476     return pred;
477 }
478
479 #ifdef CONFIG_ENCODERS
480
481 static void msmpeg4_encode_motion(MpegEncContext * s, 
482                                   int mx, int my)
483 {
484     int code;
485     MVTable *mv;
486
487     /* modulo encoding */
488     /* WARNING : you cannot reach all the MVs even with the modulo
489        encoding. This is a somewhat strange compromise they took !!!  */
490     if (mx <= -64)
491         mx += 64;
492     else if (mx >= 64)
493         mx -= 64;
494     if (my <= -64)
495         my += 64;
496     else if (my >= 64)
497         my -= 64;
498     
499     mx += 32;
500     my += 32;
501 #if 0
502     if ((unsigned)mx >= 64 ||
503         (unsigned)my >= 64) 
504         fprintf(stderr, "error mx=%d my=%d\n", mx, my);
505 #endif
506     mv = &mv_tables[s->mv_table_index];
507
508     code = mv->table_mv_index[(mx << 6) | my];
509     set_stat(ST_MV);
510     put_bits(&s->pb, 
511              mv->table_mv_bits[code], 
512              mv->table_mv_code[code]);
513     if (code == mv->n) {
514         /* escape : code litterally */
515         put_bits(&s->pb, 6, mx);
516         put_bits(&s->pb, 6, my);
517     }
518 }
519
520 static inline void handle_slices(MpegEncContext *s){
521     if (s->mb_x == 0) {
522         if (s->slice_height && (s->mb_y % s->slice_height) == 0) {
523             if(s->msmpeg4_version < 4){
524                 ff_mpeg4_clean_buffers(s);
525             }
526             s->first_slice_line = 1;
527         } else {
528             s->first_slice_line = 0; 
529         }
530     }
531 }
532
533 void msmpeg4_encode_mb(MpegEncContext * s, 
534                        DCTELEM block[6][64],
535                        int motion_x, int motion_y)
536 {
537     int cbp, coded_cbp, i;
538     int pred_x, pred_y;
539     uint8_t *coded_block;
540
541     handle_slices(s);
542     
543     if (!s->mb_intra) {
544         /* compute cbp */
545         set_stat(ST_INTER_MB);
546         cbp = 0;
547         for (i = 0; i < 6; i++) {
548             if (s->block_last_index[i] >= 0)
549                 cbp |= 1 << (5 - i);
550         }
551         if (s->use_skip_mb_code && (cbp | motion_x | motion_y) == 0) {
552             /* skip macroblock */
553             put_bits(&s->pb, 1, 1);
554             return;
555         }
556         if (s->use_skip_mb_code)
557             put_bits(&s->pb, 1, 0);     /* mb coded */
558         
559         if(s->msmpeg4_version<=2){
560             put_bits(&s->pb, 
561                      v2_mb_type[cbp&3][1], 
562                      v2_mb_type[cbp&3][0]);
563             if((cbp&3) != 3) coded_cbp= cbp ^ 0x3C;
564             else             coded_cbp= cbp;
565
566             put_bits(&s->pb, 
567                      cbpy_tab[coded_cbp>>2][1], 
568                      cbpy_tab[coded_cbp>>2][0]);
569                         
570             h263_pred_motion(s, 0, &pred_x, &pred_y);
571             msmpeg4v2_encode_motion(s, motion_x - pred_x);
572             msmpeg4v2_encode_motion(s, motion_y - pred_y);
573         }else{
574             put_bits(&s->pb, 
575                      table_mb_non_intra[cbp + 64][1], 
576                      table_mb_non_intra[cbp + 64][0]);
577
578             /* motion vector */
579             h263_pred_motion(s, 0, &pred_x, &pred_y);
580             msmpeg4_encode_motion(s, motion_x - pred_x, 
581                                   motion_y - pred_y);
582         }
583     } else {
584         /* compute cbp */
585         cbp = 0;
586         coded_cbp = 0;
587         for (i = 0; i < 6; i++) {
588             int val, pred;
589             val = (s->block_last_index[i] >= 1);
590             cbp |= val << (5 - i);
591             if (i < 4) {
592                 /* predict value for close blocks only for luma */
593                 pred = coded_block_pred(s, i, &coded_block);
594                 *coded_block = val;
595                 val = val ^ pred;
596             }
597             coded_cbp |= val << (5 - i);
598         }
599 #if 0
600         if (coded_cbp)
601             printf("cbp=%x %x\n", cbp, coded_cbp);
602 #endif
603
604         if(s->msmpeg4_version<=2){
605             if (s->pict_type == I_TYPE) {
606                 put_bits(&s->pb, 
607                          v2_intra_cbpc[cbp&3][1], v2_intra_cbpc[cbp&3][0]);
608             } else {
609                 if (s->use_skip_mb_code)
610                     put_bits(&s->pb, 1, 0);     /* mb coded */
611                 put_bits(&s->pb, 
612                          v2_mb_type[(cbp&3) + 4][1], 
613                          v2_mb_type[(cbp&3) + 4][0]);
614             }
615             put_bits(&s->pb, 1, 0);     /* no AC prediction yet */
616             put_bits(&s->pb, 
617                      cbpy_tab[cbp>>2][1], 
618                      cbpy_tab[cbp>>2][0]);
619         }else{
620             if (s->pict_type == I_TYPE) {
621                 set_stat(ST_INTRA_MB);
622                 put_bits(&s->pb, 
623                          table_mb_intra[coded_cbp][1], table_mb_intra[coded_cbp][0]);
624             } else {
625                 if (s->use_skip_mb_code)
626                     put_bits(&s->pb, 1, 0);     /* mb coded */
627                 put_bits(&s->pb, 
628                          table_mb_non_intra[cbp][1], 
629                          table_mb_non_intra[cbp][0]);
630             }
631             set_stat(ST_INTRA_MB);
632             put_bits(&s->pb, 1, 0);     /* no AC prediction yet */
633             if(s->inter_intra_pred){
634                 s->h263_aic_dir=0;
635                 put_bits(&s->pb, table_inter_intra[s->h263_aic_dir][1], table_inter_intra[s->h263_aic_dir][0]);
636             }
637         }
638     }
639
640     for (i = 0; i < 6; i++) {
641         msmpeg4_encode_block(s, block[i], i);
642     }
643 }
644
645 #endif //CONFIG_ENCODERS
646
647 /* old ffmpeg msmpeg4v3 mode */
648 static void ff_old_msmpeg4_dc_scale(MpegEncContext * s)
649 {
650     if (s->qscale < 5){
651         s->y_dc_scale = 8;
652         s->c_dc_scale = 8;
653     }else if (s->qscale < 9){
654         s->y_dc_scale = 2 * s->qscale;
655         s->c_dc_scale = (s->qscale + 13)>>1;
656     }else{
657         s->y_dc_scale = s->qscale + 8;
658         s->c_dc_scale = (s->qscale + 13)>>1;
659     }
660 }
661
662 static inline int msmpeg4v1_pred_dc(MpegEncContext * s, int n, 
663                                     int32_t **dc_val_ptr)
664 {
665     int i;
666
667     if (n < 4) {
668         i= 0;
669     } else {
670         i= n-3;
671     }
672     
673     *dc_val_ptr= &s->last_dc[i];
674     return s->last_dc[i]; 
675 }
676
677 static int get_dc(uint8_t *src, int stride, int scale)
678 {
679     int y;
680     int sum=0;
681     for(y=0; y<8; y++){
682         int x;
683         for(x=0; x<8; x++){
684             sum+=src[x + y*stride];
685         }
686     }
687     return (sum + (scale>>1))/scale;
688 }
689
690 /* dir = 0: left, dir = 1: top prediction */
691 static inline int msmpeg4_pred_dc(MpegEncContext * s, int n, 
692                              uint16_t **dc_val_ptr, int *dir_ptr)
693 {
694     int a, b, c, wrap, pred, scale;
695     int16_t *dc_val;
696
697     /* find prediction */
698     if (n < 4) {
699         scale = s->y_dc_scale;
700     } else {
701         scale = s->c_dc_scale;
702     }
703     
704     wrap = s->block_wrap[n];
705     dc_val= s->dc_val[0] + s->block_index[n];
706
707     /* B C
708      * A X 
709      */
710     a = dc_val[ - 1];
711     b = dc_val[ - 1 - wrap];
712     c = dc_val[ - wrap];
713     
714     if(s->first_slice_line && (n&2)==0 && s->msmpeg4_version<4){
715         b=c=1024;
716     }
717
718     /* XXX: the following solution consumes divisions, but it does not
719        necessitate to modify mpegvideo.c. The problem comes from the
720        fact they decided to store the quantized DC (which would lead
721        to problems if Q could vary !) */
722 #if defined ARCH_X86 && !defined PIC
723     asm volatile(
724         "movl %3, %%eax         \n\t"
725         "shrl $1, %%eax         \n\t"
726         "addl %%eax, %2         \n\t"
727         "addl %%eax, %1         \n\t"
728         "addl %0, %%eax         \n\t"
729         "mull %4                \n\t"
730         "movl %%edx, %0         \n\t"
731         "movl %1, %%eax         \n\t"
732         "mull %4                \n\t"
733         "movl %%edx, %1         \n\t"
734         "movl %2, %%eax         \n\t"
735         "mull %4                \n\t"
736         "movl %%edx, %2         \n\t"
737         : "+b" (a), "+c" (b), "+D" (c)
738         : "g" (scale), "S" (inverse[scale])
739         : "%eax", "%edx"
740     );
741 #else
742     /* #elif defined (ARCH_ALPHA) */
743     /* Divisions are extremely costly on Alpha; optimize the most
744        common case. But they are costly everywhere...
745      */
746     if (scale == 8) {
747         a = (a + (8 >> 1)) / 8;
748         b = (b + (8 >> 1)) / 8;
749         c = (c + (8 >> 1)) / 8;
750     } else {
751         a = (a + (scale >> 1)) / scale;
752         b = (b + (scale >> 1)) / scale;
753         c = (c + (scale >> 1)) / scale;
754     }
755 #endif
756     /* XXX: WARNING: they did not choose the same test as MPEG4. This
757        is very important ! */
758     if(s->msmpeg4_version>3){
759         if(s->inter_intra_pred){
760             uint8_t *dest;
761             int wrap;
762             
763             if(n==1){
764                 pred=a;
765                 *dir_ptr = 0;
766             }else if(n==2){
767                 pred=c;
768                 *dir_ptr = 1;
769             }else if(n==3){
770                 if (abs(a - b) < abs(b - c)) {
771                     pred = c;
772                     *dir_ptr = 1;
773                 } else {
774                     pred = a;
775                     *dir_ptr = 0;
776                 }
777             }else{
778                 if(n<4){
779                     wrap= s->linesize;
780                     dest= s->current_picture.data[0] + (((n>>1) + 2*s->mb_y) * 8*  wrap ) + ((n&1) + 2*s->mb_x) * 8;
781                 }else{
782                     wrap= s->uvlinesize;
783                     dest= s->current_picture.data[n-3] + (s->mb_y * 8 * wrap) + s->mb_x * 8;
784                 }
785                 if(s->mb_x==0) a= (1024 + (scale>>1))/scale;
786                 else           a= get_dc(dest-8, wrap, scale*8);
787                 if(s->mb_y==0) c= (1024 + (scale>>1))/scale;
788                 else           c= get_dc(dest-8*wrap, wrap, scale*8);
789                 
790                 if (s->h263_aic_dir==0) {
791                     pred= a;
792                     *dir_ptr = 0;
793                 }else if (s->h263_aic_dir==1) {
794                     if(n==0){
795                         pred= c;
796                         *dir_ptr = 1;
797                     }else{
798                         pred= a;
799                         *dir_ptr = 0;
800                     }
801                 }else if (s->h263_aic_dir==2) {
802                     if(n==0){
803                         pred= a;
804                         *dir_ptr = 0;
805                     }else{
806                         pred= c;
807                         *dir_ptr = 1;
808                     }
809                 } else {
810                     pred= c;
811                     *dir_ptr = 1;
812                 }
813             }
814         }else{
815             if (abs(a - b) < abs(b - c)) {
816                 pred = c;
817                 *dir_ptr = 1;
818             } else {
819                 pred = a;
820                 *dir_ptr = 0;
821             }
822         }
823     }else{
824         if (abs(a - b) <= abs(b - c)) {
825             pred = c;
826             *dir_ptr = 1;
827         } else {
828             pred = a;
829             *dir_ptr = 0;
830         }
831     }
832
833     /* update predictor */
834     *dc_val_ptr = &dc_val[0];
835     return pred;
836 }
837
838 #define DC_MAX 119
839
840 #ifdef CONFIG_ENCODERS
841
842 static void msmpeg4_encode_dc(MpegEncContext * s, int level, int n, int *dir_ptr)
843 {
844     int sign, code;
845     int pred;
846
847     if(s->msmpeg4_version==1){
848         int32_t *dc_val;
849         pred = msmpeg4v1_pred_dc(s, n, &dc_val);
850         
851         /* update predictor */
852         *dc_val= level;
853     }else{
854         uint16_t *dc_val;
855         pred = msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
856
857         /* update predictor */
858         if (n < 4) {
859             *dc_val = level * s->y_dc_scale;
860         } else {
861             *dc_val = level * s->c_dc_scale;
862         }
863     }
864
865     /* do the prediction */
866     level -= pred;
867
868     if(s->msmpeg4_version<=2){
869         if (n < 4) {
870             put_bits(&s->pb, 
871                      v2_dc_lum_table[level+256][1],
872                      v2_dc_lum_table[level+256][0]);
873         }else{
874             put_bits(&s->pb, 
875                      v2_dc_chroma_table[level+256][1],
876                      v2_dc_chroma_table[level+256][0]);
877         }
878     }else{
879         sign = 0;
880         if (level < 0) {
881             level = -level;
882             sign = 1;
883         }
884         code = level;
885         if (code > DC_MAX) 
886             code = DC_MAX;
887
888         if (s->dc_table_index == 0) {
889             if (n < 4) {
890                 put_bits(&s->pb, table0_dc_lum[code][1], table0_dc_lum[code][0]);
891             } else {
892                 put_bits(&s->pb, table0_dc_chroma[code][1], table0_dc_chroma[code][0]);
893             }
894         } else {
895             if (n < 4) {
896                 put_bits(&s->pb, table1_dc_lum[code][1], table1_dc_lum[code][0]);
897             } else {
898                 put_bits(&s->pb, table1_dc_chroma[code][1], table1_dc_chroma[code][0]);
899             }
900         }
901             
902         if (code == DC_MAX)
903             put_bits(&s->pb, 8, level);
904             
905         if (level != 0) {
906             put_bits(&s->pb, 1, sign);
907         }
908     }
909 }
910
911 /* Encoding of a block. Very similar to MPEG4 except for a different
912    escape coding (same as H263) and more vlc tables.
913  */
914 static inline void msmpeg4_encode_block(MpegEncContext * s, DCTELEM * block, int n)
915 {
916     int level, run, last, i, j, last_index;
917     int last_non_zero, sign, slevel;
918     int code, run_diff, dc_pred_dir;
919     const RLTable *rl;
920     const uint8_t *scantable;
921
922     if (s->mb_intra) {
923         set_stat(ST_DC);
924         msmpeg4_encode_dc(s, block[0], n, &dc_pred_dir);
925         i = 1;
926         if (n < 4) {
927             rl = &rl_table[s->rl_table_index];
928         } else {
929             rl = &rl_table[3 + s->rl_chroma_table_index];
930         }
931         run_diff = 0;
932         scantable= s->intra_scantable.permutated;
933         set_stat(ST_INTRA_AC);
934     } else {
935         i = 0;
936         rl = &rl_table[3 + s->rl_table_index];
937         if(s->msmpeg4_version<=2)
938             run_diff = 0;
939         else
940             run_diff = 1;
941         scantable= s->inter_scantable.permutated;
942         set_stat(ST_INTER_AC);
943     }
944
945     /* recalculate block_last_index for M$ wmv1 */
946     if(s->msmpeg4_version>=4 && s->block_last_index[n]>0){
947         for(last_index=63; last_index>=0; last_index--){
948             if(block[scantable[last_index]]) break;
949         }
950         s->block_last_index[n]= last_index;
951     }else
952         last_index = s->block_last_index[n];
953     /* AC coefs */
954     last_non_zero = i - 1;
955     for (; i <= last_index; i++) {
956         j = scantable[i];
957         level = block[j];
958         if (level) {
959             run = i - last_non_zero - 1;
960             last = (i == last_index);
961             sign = 0;
962             slevel = level;
963             if (level < 0) {
964                 sign = 1;
965                 level = -level;
966             }
967
968             if(level<=MAX_LEVEL && run<=MAX_RUN){
969                 s->ac_stats[s->mb_intra][n>3][level][run][last]++;
970             }
971 #if 0
972 else
973     s->ac_stats[s->mb_intra][n>3][40][63][0]++; //esc3 like
974 #endif
975             code = get_rl_index(rl, last, run, level);
976             put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
977             if (code == rl->n) {
978                 int level1, run1;
979
980                 level1 = level - rl->max_level[last][run];
981                 if (level1 < 1) 
982                     goto esc2;
983                 code = get_rl_index(rl, last, run, level1);
984                 if (code == rl->n) {
985                 esc2:
986                     put_bits(&s->pb, 1, 0);
987                     if (level > MAX_LEVEL)
988                         goto esc3;
989                     run1 = run - rl->max_run[last][level] - run_diff;
990                     if (run1 < 0)
991                         goto esc3;
992                     code = get_rl_index(rl, last, run1, level);
993                     if (code == rl->n) {
994                     esc3:
995                         /* third escape */
996                         put_bits(&s->pb, 1, 0);
997                         put_bits(&s->pb, 1, last);
998                         if(s->msmpeg4_version>=4){
999                             if(s->esc3_level_length==0){
1000                                 s->esc3_level_length=8;
1001                                 s->esc3_run_length= 6;
1002                                 if(s->qscale<8)
1003                                     put_bits(&s->pb, 6, 3);
1004                                 else
1005                                     put_bits(&s->pb, 8, 3);
1006                             }
1007                             put_bits(&s->pb, s->esc3_run_length, run);
1008                             put_bits(&s->pb, 1, sign);
1009                             put_bits(&s->pb, s->esc3_level_length, level);
1010                         }else{
1011                             put_bits(&s->pb, 6, run);
1012                             put_bits(&s->pb, 8, slevel & 0xff);
1013                         }
1014                     } else {
1015                         /* second escape */
1016                         put_bits(&s->pb, 1, 1);
1017                         put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
1018                         put_bits(&s->pb, 1, sign);
1019                     }
1020                 } else {
1021                     /* first escape */
1022                     put_bits(&s->pb, 1, 1);
1023                     put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
1024                     put_bits(&s->pb, 1, sign);
1025                 }
1026             } else {
1027                 put_bits(&s->pb, 1, sign);
1028             }
1029             last_non_zero = i;
1030         }
1031     }
1032 }
1033
1034 #endif //CONFIG_ENCODERS
1035
1036 /****************************************/
1037 /* decoding stuff */
1038
1039 static VLC mb_non_intra_vlc[4];
1040 static VLC mb_intra_vlc;
1041 static VLC dc_lum_vlc[2];
1042 static VLC dc_chroma_vlc[2];
1043 static VLC v2_dc_lum_vlc;
1044 static VLC v2_dc_chroma_vlc;
1045 static VLC cbpy_vlc;
1046 static VLC v2_intra_cbpc_vlc;
1047 static VLC v2_mb_type_vlc;
1048 static VLC v2_mv_vlc;
1049 static VLC v1_intra_cbpc_vlc;
1050 static VLC v1_inter_cbpc_vlc;
1051 static VLC inter_intra_vlc;
1052
1053 /* this table is practically identical to the one from h263 except that its inverted */
1054 static void init_h263_dc_for_msmpeg4(void)
1055 {
1056         int level, uni_code, uni_len;
1057
1058         for(level=-256; level<256; level++){
1059             int size, v, l;
1060             /* find number of bits */
1061             size = 0;
1062             v = abs(level);
1063             while (v) {
1064                 v >>= 1;
1065                     size++;
1066             }
1067
1068             if (level < 0)
1069                 l= (-level) ^ ((1 << size) - 1);
1070             else
1071                 l= level;
1072
1073             /* luminance h263 */
1074             uni_code= DCtab_lum[size][0];
1075             uni_len = DCtab_lum[size][1];
1076             uni_code ^= (1<<uni_len)-1; //M$ doesnt like compatibility
1077
1078             if (size > 0) {
1079                 uni_code<<=size; uni_code|=l;
1080                 uni_len+=size;
1081                 if (size > 8){
1082                     uni_code<<=1; uni_code|=1;
1083                     uni_len++;
1084                 }
1085             }
1086             v2_dc_lum_table[level+256][0]= uni_code;
1087             v2_dc_lum_table[level+256][1]= uni_len;
1088
1089             /* chrominance h263 */
1090             uni_code= DCtab_chrom[size][0];
1091             uni_len = DCtab_chrom[size][1];
1092             uni_code ^= (1<<uni_len)-1; //M$ doesnt like compatibility
1093             
1094             if (size > 0) {
1095                 uni_code<<=size; uni_code|=l;
1096                 uni_len+=size;
1097                 if (size > 8){
1098                     uni_code<<=1; uni_code|=1;
1099                     uni_len++;
1100                 }
1101             }
1102             v2_dc_chroma_table[level+256][0]= uni_code;
1103             v2_dc_chroma_table[level+256][1]= uni_len;
1104
1105         }
1106 }
1107
1108 /* init all vlc decoding tables */
1109 int ff_msmpeg4_decode_init(MpegEncContext *s)
1110 {
1111     static int done = 0;
1112     int i;
1113     MVTable *mv;
1114
1115     common_init(s);
1116
1117     if (!done) {
1118         done = 1;
1119
1120         for(i=0;i<NB_RL_TABLES;i++) {
1121             init_rl(&rl_table[i]);
1122             init_vlc_rl(&rl_table[i]);
1123         }
1124         for(i=0;i<2;i++) {
1125             mv = &mv_tables[i];
1126             init_vlc(&mv->vlc, MV_VLC_BITS, mv->n + 1, 
1127                      mv->table_mv_bits, 1, 1,
1128                      mv->table_mv_code, 2, 2);
1129         }
1130
1131         init_vlc(&dc_lum_vlc[0], DC_VLC_BITS, 120, 
1132                  &table0_dc_lum[0][1], 8, 4,
1133                  &table0_dc_lum[0][0], 8, 4);
1134         init_vlc(&dc_chroma_vlc[0], DC_VLC_BITS, 120, 
1135                  &table0_dc_chroma[0][1], 8, 4,
1136                  &table0_dc_chroma[0][0], 8, 4);
1137         init_vlc(&dc_lum_vlc[1], DC_VLC_BITS, 120, 
1138                  &table1_dc_lum[0][1], 8, 4,
1139                  &table1_dc_lum[0][0], 8, 4);
1140         init_vlc(&dc_chroma_vlc[1], DC_VLC_BITS, 120, 
1141                  &table1_dc_chroma[0][1], 8, 4,
1142                  &table1_dc_chroma[0][0], 8, 4);
1143     
1144         init_vlc(&v2_dc_lum_vlc, DC_VLC_BITS, 512, 
1145                  &v2_dc_lum_table[0][1], 8, 4,
1146                  &v2_dc_lum_table[0][0], 8, 4);
1147         init_vlc(&v2_dc_chroma_vlc, DC_VLC_BITS, 512, 
1148                  &v2_dc_chroma_table[0][1], 8, 4,
1149                  &v2_dc_chroma_table[0][0], 8, 4);
1150     
1151         init_vlc(&cbpy_vlc, CBPY_VLC_BITS, 16,
1152                  &cbpy_tab[0][1], 2, 1,
1153                  &cbpy_tab[0][0], 2, 1);
1154         init_vlc(&v2_intra_cbpc_vlc, V2_INTRA_CBPC_VLC_BITS, 4,
1155                  &v2_intra_cbpc[0][1], 2, 1,
1156                  &v2_intra_cbpc[0][0], 2, 1);
1157         init_vlc(&v2_mb_type_vlc, V2_MB_TYPE_VLC_BITS, 8,
1158                  &v2_mb_type[0][1], 2, 1,
1159                  &v2_mb_type[0][0], 2, 1);
1160         init_vlc(&v2_mv_vlc, V2_MV_VLC_BITS, 33,
1161                  &mvtab[0][1], 2, 1,
1162                  &mvtab[0][0], 2, 1);
1163
1164         for(i=0; i<4; i++){
1165             init_vlc(&mb_non_intra_vlc[i], MB_NON_INTRA_VLC_BITS, 128, 
1166                      &wmv2_inter_table[i][0][1], 8, 4,
1167                      &wmv2_inter_table[i][0][0], 8, 4); //FIXME name?
1168         }
1169         
1170         init_vlc(&mb_intra_vlc, MB_INTRA_VLC_BITS, 64, 
1171                  &table_mb_intra[0][1], 4, 2,
1172                  &table_mb_intra[0][0], 4, 2);
1173         
1174         init_vlc(&v1_intra_cbpc_vlc, V1_INTRA_CBPC_VLC_BITS, 8, 
1175                  intra_MCBPC_bits, 1, 1,
1176                  intra_MCBPC_code, 1, 1);
1177         init_vlc(&v1_inter_cbpc_vlc, V1_INTER_CBPC_VLC_BITS, 25, 
1178                  inter_MCBPC_bits, 1, 1,
1179                  inter_MCBPC_code, 1, 1);
1180         
1181         init_vlc(&inter_intra_vlc, INTER_INTRA_VLC_BITS, 4, 
1182                  &table_inter_intra[0][1], 2, 1,
1183                  &table_inter_intra[0][0], 2, 1);
1184     }
1185     
1186     switch(s->msmpeg4_version){
1187     case 1:
1188     case 2:
1189         s->decode_mb= msmpeg4v12_decode_mb;
1190         break;
1191     case 3:
1192     case 4:
1193         s->decode_mb= msmpeg4v34_decode_mb;
1194         break;
1195     case 5:
1196         s->decode_mb= wmv2_decode_mb;
1197         break;
1198     }
1199     
1200     s->slice_height= s->mb_height; //to avoid 1/0 if the first frame isnt a keyframe
1201     
1202     return 0;
1203 }
1204
1205 static int decode012(GetBitContext *gb)
1206 {
1207     int n;
1208     n = get_bits1(gb);
1209     if (n == 0)
1210         return 0;
1211     else
1212         return get_bits1(gb) + 1;
1213 }
1214
1215 int msmpeg4_decode_picture_header(MpegEncContext * s)
1216 {
1217     int code;
1218
1219 #if 0
1220 {
1221 int i;
1222 for(i=0; i<s->gb.size_in_bits; i++)
1223     printf("%d", get_bits1(&s->gb));
1224 //    get_bits1(&s->gb);
1225 printf("END\n");
1226 return -1;
1227 }
1228 #endif
1229
1230     if(s->msmpeg4_version==1){
1231         int start_code, num;
1232         start_code = (get_bits(&s->gb, 16)<<16) | get_bits(&s->gb, 16);
1233         if(start_code!=0x00000100){
1234             fprintf(stderr, "invalid startcode\n");
1235             return -1;
1236         }
1237
1238         num= get_bits(&s->gb, 5); // frame number */
1239     }
1240
1241     s->pict_type = get_bits(&s->gb, 2) + 1;
1242     if (s->pict_type != I_TYPE &&
1243         s->pict_type != P_TYPE){
1244         fprintf(stderr, "invalid picture type\n");
1245         return -1;
1246     }
1247 #if 0
1248 {
1249     static int had_i=0;
1250     if(s->pict_type == I_TYPE) had_i=1;
1251     if(!had_i) return -1;
1252 }
1253 #endif
1254     s->qscale = get_bits(&s->gb, 5);
1255     if(s->qscale==0){
1256         fprintf(stderr, "invalid qscale\n");
1257         return -1;
1258     }
1259
1260     if (s->pict_type == I_TYPE) {
1261         code = get_bits(&s->gb, 5); 
1262         if(s->msmpeg4_version==1){
1263             if(code==0 || code>s->mb_height){
1264                 fprintf(stderr, "invalid slice height %d\n", code);
1265                 return -1;
1266             }
1267
1268             s->slice_height = code;
1269         }else{
1270             /* 0x17: one slice, 0x18: two slices, ... */
1271             if (code < 0x17){
1272                 fprintf(stderr, "error, slice code was %X\n", code);
1273                 return -1;
1274             }
1275
1276             s->slice_height = s->mb_height / (code - 0x16);
1277         }
1278
1279         switch(s->msmpeg4_version){
1280         case 1:
1281         case 2:
1282             s->rl_chroma_table_index = 2;
1283             s->rl_table_index = 2;
1284
1285             s->dc_table_index = 0; //not used
1286             break;
1287         case 3:
1288             s->rl_chroma_table_index = decode012(&s->gb);
1289             s->rl_table_index = decode012(&s->gb);
1290
1291             s->dc_table_index = get_bits1(&s->gb);
1292             break;
1293         case 4:
1294             msmpeg4_decode_ext_header(s, (2+5+5+17+7)/8);
1295
1296             if(s->bit_rate > MBAC_BITRATE) s->per_mb_rl_table= get_bits1(&s->gb);
1297             else                           s->per_mb_rl_table= 0;
1298             
1299             if(!s->per_mb_rl_table){
1300                 s->rl_chroma_table_index = decode012(&s->gb);
1301                 s->rl_table_index = decode012(&s->gb);
1302             }
1303
1304             s->dc_table_index = get_bits1(&s->gb);
1305             s->inter_intra_pred= 0;
1306             break;
1307         }
1308         s->no_rounding = 1;
1309 /*      printf("qscale:%d rlc:%d rl:%d dc:%d mbrl:%d slice:%d   \n", 
1310                 s->qscale,
1311                 s->rl_chroma_table_index,
1312                 s->rl_table_index, 
1313                 s->dc_table_index,
1314                 s->per_mb_rl_table,
1315                 s->slice_height);*/
1316     } else {
1317         switch(s->msmpeg4_version){
1318         case 1:
1319         case 2:
1320             if(s->msmpeg4_version==1)
1321                 s->use_skip_mb_code = 1;
1322             else
1323                 s->use_skip_mb_code = get_bits1(&s->gb);
1324             s->rl_table_index = 2;
1325             s->rl_chroma_table_index = s->rl_table_index;
1326             s->dc_table_index = 0; //not used
1327             s->mv_table_index = 0;
1328             break;
1329         case 3:
1330             s->use_skip_mb_code = get_bits1(&s->gb);
1331             s->rl_table_index = decode012(&s->gb);
1332             s->rl_chroma_table_index = s->rl_table_index;
1333
1334             s->dc_table_index = get_bits1(&s->gb);
1335
1336             s->mv_table_index = get_bits1(&s->gb);
1337             break;
1338         case 4:
1339             s->use_skip_mb_code = get_bits1(&s->gb);
1340
1341             if(s->bit_rate > MBAC_BITRATE) s->per_mb_rl_table= get_bits1(&s->gb);
1342             else                           s->per_mb_rl_table= 0;
1343
1344             if(!s->per_mb_rl_table){
1345                 s->rl_table_index = decode012(&s->gb);
1346                 s->rl_chroma_table_index = s->rl_table_index;
1347             }
1348
1349             s->dc_table_index = get_bits1(&s->gb);
1350
1351             s->mv_table_index = get_bits1(&s->gb);
1352             s->inter_intra_pred= (s->width*s->height < 320*240 && s->bit_rate<=II_BITRATE);
1353             break;
1354         }
1355 /*      printf("skip:%d rl:%d rlc:%d dc:%d mv:%d mbrl:%d qp:%d   \n", 
1356                 s->use_skip_mb_code, 
1357                 s->rl_table_index, 
1358                 s->rl_chroma_table_index, 
1359                 s->dc_table_index,
1360                 s->mv_table_index,
1361                 s->per_mb_rl_table,
1362                 s->qscale);*/
1363         if(s->flipflop_rounding){
1364             s->no_rounding ^= 1;
1365         }else{
1366             s->no_rounding = 0;
1367         }
1368     }
1369 //printf("%d %d %d %d %d\n", s->pict_type, s->bit_rate, s->inter_intra_pred, s->width, s->height);
1370
1371     s->esc3_level_length= 0;
1372     s->esc3_run_length= 0;
1373
1374 #ifdef DEBUG
1375     printf("*****frame %d:\n", frame_count++);
1376 #endif
1377     return 0;
1378 }
1379
1380 int msmpeg4_decode_ext_header(MpegEncContext * s, int buf_size)
1381 {
1382     int left= buf_size*8 - get_bits_count(&s->gb);
1383     int length= s->msmpeg4_version>=3 ? 17 : 16;
1384     /* the alt_bitstream reader could read over the end so we need to check it */
1385     if(left>=length && left<length+8)
1386     {
1387         int fps;
1388
1389         fps= get_bits(&s->gb, 5);
1390         s->bit_rate= get_bits(&s->gb, 11)*1024;
1391         if(s->msmpeg4_version>=3)
1392             s->flipflop_rounding= get_bits1(&s->gb);
1393         else
1394             s->flipflop_rounding= 0;
1395
1396 //        printf("fps:%2d bps:%2d roundingType:%1d\n", fps, s->bit_rate/1024, s->flipflop_rounding);
1397     }
1398     else if(left<length+8)
1399     {
1400         s->flipflop_rounding= 0;
1401         printf("ext header missing, %d left\n", left);
1402     }
1403     else
1404     {
1405         fprintf(stderr, "I frame too long, ignoring ext header\n");
1406     }
1407
1408     return 0;
1409 }
1410
1411 static inline void msmpeg4_memsetw(short *tab, int val, int n)
1412 {
1413     int i;
1414     for(i=0;i<n;i++)
1415         tab[i] = val;
1416 }
1417
1418 #ifdef CONFIG_ENCODERS
1419
1420 static void msmpeg4v2_encode_motion(MpegEncContext * s, int val)
1421 {
1422     int range, bit_size, sign, code, bits;
1423
1424     if (val == 0) {
1425         /* zero vector */
1426         code = 0;
1427         put_bits(&s->pb, mvtab[code][1], mvtab[code][0]);
1428     } else {
1429         bit_size = s->f_code - 1;
1430         range = 1 << bit_size;
1431         if (val <= -64)
1432             val += 64;
1433         else if (val >= 64)
1434             val -= 64;
1435
1436         if (val >= 0) {
1437             sign = 0;
1438         } else {
1439             val = -val;
1440             sign = 1;
1441         }
1442         val--;
1443         code = (val >> bit_size) + 1;
1444         bits = val & (range - 1);
1445
1446         put_bits(&s->pb, mvtab[code][1] + 1, (mvtab[code][0] << 1) | sign); 
1447         if (bit_size > 0) {
1448             put_bits(&s->pb, bit_size, bits);
1449         }
1450     }
1451 }
1452
1453 #endif //CONFIG_ENCODERS
1454
1455 /* this is identical to h263 except that its range is multiplied by 2 */
1456 static int msmpeg4v2_decode_motion(MpegEncContext * s, int pred, int f_code)
1457 {
1458     int code, val, sign, shift;
1459
1460     code = get_vlc2(&s->gb, v2_mv_vlc.table, V2_MV_VLC_BITS, 2);
1461 //     printf("MV code %d at %d %d pred: %d\n", code, s->mb_x,s->mb_y, pred);
1462     if (code < 0)
1463         return 0xffff;
1464
1465     if (code == 0)
1466         return pred;
1467     sign = get_bits1(&s->gb);
1468     shift = f_code - 1;
1469     val = (code - 1) << shift;
1470     if (shift > 0)
1471         val |= get_bits(&s->gb, shift);
1472     val++;
1473     if (sign)
1474         val = -val;
1475
1476     val += pred;
1477     if (val <= -64)
1478         val += 64;
1479     else if (val >= 64)
1480         val -= 64;
1481
1482     return val;
1483 }
1484
1485 static int msmpeg4v12_decode_mb(MpegEncContext *s, DCTELEM block[6][64])
1486 {
1487     int cbp, code, i;
1488     
1489     s->error_status_table[s->mb_x + s->mb_y*s->mb_width]= 0;
1490     
1491     if (s->pict_type == P_TYPE) {
1492         if (s->use_skip_mb_code) {
1493             if (get_bits1(&s->gb)) {
1494                 /* skip mb */
1495                 s->mb_intra = 0;
1496                 for(i=0;i<6;i++)
1497                     s->block_last_index[i] = -1;
1498                 s->mv_dir = MV_DIR_FORWARD;
1499                 s->mv_type = MV_TYPE_16X16;
1500                 s->mv[0][0][0] = 0;
1501                 s->mv[0][0][1] = 0;
1502                 s->mb_skiped = 1;
1503                 return 0;
1504             }
1505         }
1506
1507         if(s->msmpeg4_version==2)
1508             code = get_vlc2(&s->gb, v2_mb_type_vlc.table, V2_MB_TYPE_VLC_BITS, 1);
1509         else
1510             code = get_vlc2(&s->gb, v1_inter_cbpc_vlc.table, V1_INTER_CBPC_VLC_BITS, 3);
1511         if(code<0 || code>7){
1512             fprintf(stderr, "cbpc %d invalid at %d %d\n", code, s->mb_x, s->mb_y);
1513             return -1;
1514         }
1515
1516         s->mb_intra = code >>2;
1517     
1518         cbp = code & 0x3;
1519     } else {
1520         s->mb_intra = 1;
1521         if(s->msmpeg4_version==2)
1522             cbp= get_vlc2(&s->gb, v2_intra_cbpc_vlc.table, V2_INTRA_CBPC_VLC_BITS, 1);
1523         else
1524             cbp= get_vlc2(&s->gb, v1_intra_cbpc_vlc.table, V1_INTRA_CBPC_VLC_BITS, 1);
1525         if(cbp<0 || cbp>3){
1526             fprintf(stderr, "cbpc %d invalid at %d %d\n", cbp, s->mb_x, s->mb_y);
1527             return -1;
1528         }
1529     }
1530
1531     if (!s->mb_intra) {
1532         int mx, my, cbpy;
1533         
1534         cbpy= get_vlc2(&s->gb, cbpy_vlc.table, CBPY_VLC_BITS, 1);
1535         if(cbpy<0){
1536             fprintf(stderr, "cbpy %d invalid at %d %d\n", cbp, s->mb_x, s->mb_y);
1537             return -1;
1538         }
1539
1540         cbp|= cbpy<<2;
1541         if(s->msmpeg4_version==1 || (cbp&3) != 3) cbp^= 0x3C;
1542         
1543         h263_pred_motion(s, 0, &mx, &my);
1544         mx= msmpeg4v2_decode_motion(s, mx, 1);
1545         my= msmpeg4v2_decode_motion(s, my, 1);
1546         
1547         s->mv_dir = MV_DIR_FORWARD;
1548         s->mv_type = MV_TYPE_16X16;
1549         s->mv[0][0][0] = mx;
1550         s->mv[0][0][1] = my;
1551     } else {
1552         if(s->msmpeg4_version==2){
1553             s->ac_pred = get_bits1(&s->gb);
1554             cbp|= get_vlc2(&s->gb, cbpy_vlc.table, CBPY_VLC_BITS, 1)<<2; //FIXME check errors
1555         } else{
1556             s->ac_pred = 0;
1557             cbp|= get_vlc2(&s->gb, cbpy_vlc.table, CBPY_VLC_BITS, 1)<<2; //FIXME check errors
1558             if(s->pict_type==P_TYPE) cbp^=0x3C;
1559         }
1560     }
1561
1562     for (i = 0; i < 6; i++) {
1563         if (msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
1564         {
1565              fprintf(stderr,"\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
1566              return -1;
1567         }
1568     }
1569     return 0;
1570 }
1571
1572 static int msmpeg4v34_decode_mb(MpegEncContext *s, DCTELEM block[6][64])
1573 {
1574     int cbp, code, i;
1575     uint8_t *coded_val;
1576
1577 #ifdef PRINT_MB
1578 if(s->mb_x==0){
1579     printf("\n");
1580     if(s->mb_y==0) printf("\n");
1581 }
1582 #endif
1583
1584     s->error_status_table[s->mb_x + s->mb_y*s->mb_width]= 0;
1585     
1586     if (s->pict_type == P_TYPE) {
1587         set_stat(ST_INTER_MB);
1588         if (s->use_skip_mb_code) {
1589             if (get_bits1(&s->gb)) {
1590                 /* skip mb */
1591                 s->mb_intra = 0;
1592                 for(i=0;i<6;i++)
1593                     s->block_last_index[i] = -1;
1594                 s->mv_dir = MV_DIR_FORWARD;
1595                 s->mv_type = MV_TYPE_16X16;
1596                 s->mv[0][0][0] = 0;
1597                 s->mv[0][0][1] = 0;
1598                 s->mb_skiped = 1;
1599 #ifdef PRINT_MB
1600 printf("S ");
1601 #endif
1602                 return 0;
1603             }
1604         }
1605         
1606         code = get_vlc2(&s->gb, mb_non_intra_vlc[DEFAULT_INTER_INDEX].table, MB_NON_INTRA_VLC_BITS, 3);
1607         if (code < 0)
1608             return -1;
1609         //s->mb_intra = (code & 0x40) ? 0 : 1;
1610         s->mb_intra = (~code & 0x40) >> 6;
1611             
1612         cbp = code & 0x3f;
1613     } else {
1614         set_stat(ST_INTRA_MB);
1615         s->mb_intra = 1;
1616         code = get_vlc2(&s->gb, mb_intra_vlc.table, MB_INTRA_VLC_BITS, 2);
1617         if (code < 0)
1618             return -1;
1619         /* predict coded block pattern */
1620         cbp = 0;
1621         for(i=0;i<6;i++) {
1622             int val = ((code >> (5 - i)) & 1);
1623             if (i < 4) {
1624                 int pred = coded_block_pred(s, i, &coded_val);
1625                 val = val ^ pred;
1626                 *coded_val = val;
1627             }
1628             cbp |= val << (5 - i);
1629         }
1630     }
1631
1632     if (!s->mb_intra) {
1633         int mx, my;
1634 //printf("P at %d %d\n", s->mb_x, s->mb_y);
1635         if(s->per_mb_rl_table && cbp){
1636             s->rl_table_index = decode012(&s->gb);
1637             s->rl_chroma_table_index = s->rl_table_index;
1638         }
1639         set_stat(ST_MV);
1640         h263_pred_motion(s, 0, &mx, &my);
1641         if (msmpeg4_decode_motion(s, &mx, &my) < 0)
1642             return -1;
1643         s->mv_dir = MV_DIR_FORWARD;
1644         s->mv_type = MV_TYPE_16X16;
1645         s->mv[0][0][0] = mx;
1646         s->mv[0][0][1] = my;
1647 #ifdef PRINT_MB
1648 printf("P ");
1649 #endif
1650     } else {
1651 //printf("I at %d %d %d %06X\n", s->mb_x, s->mb_y, ((cbp&3)? 1 : 0) +((cbp&0x3C)? 2 : 0), show_bits(&s->gb, 24));
1652         set_stat(ST_INTRA_MB);
1653         s->ac_pred = get_bits1(&s->gb);
1654 #ifdef PRINT_MB
1655 printf("%c", s->ac_pred ? 'A' : 'I');
1656 #endif
1657         if(s->inter_intra_pred){
1658             s->h263_aic_dir= get_vlc2(&s->gb, inter_intra_vlc.table, INTER_INTRA_VLC_BITS, 1);
1659 //            printf("%d%d %d %d/", s->ac_pred, s->h263_aic_dir, s->mb_x, s->mb_y);
1660         }
1661         if(s->per_mb_rl_table && cbp){
1662             s->rl_table_index = decode012(&s->gb);
1663             s->rl_chroma_table_index = s->rl_table_index;
1664         }
1665     }
1666
1667     for (i = 0; i < 6; i++) {
1668         if (msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
1669         {
1670             fprintf(stderr,"\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
1671             return -1;
1672         }
1673     }
1674     
1675     return 0;
1676 }
1677 //#define ERROR_DETAILS
1678 static inline int msmpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
1679                               int n, int coded, const uint8_t *scan_table)
1680 {
1681     int level, i, last, run, run_diff;
1682     int dc_pred_dir;
1683     RLTable *rl;
1684     RL_VLC_ELEM *rl_vlc;
1685     int qmul, qadd;
1686
1687     if (s->mb_intra) {
1688         qmul=1;
1689         qadd=0;
1690
1691         /* DC coef */
1692         set_stat(ST_DC);
1693         level = msmpeg4_decode_dc(s, n, &dc_pred_dir);
1694 #ifdef PRINT_MB
1695 {
1696     static int c;
1697     if(n==0) c=0;
1698     if(n==4) printf("%X", c);
1699     c+= c +dc_pred_dir;
1700 }
1701 #endif
1702         if (level < 0){
1703             fprintf(stderr, "dc overflow- block: %d qscale: %d//\n", n, s->qscale);
1704             if(s->inter_intra_pred) level=0;
1705             else                    return -1;
1706         }
1707         if (n < 4) {
1708             rl = &rl_table[s->rl_table_index];
1709             if(level > 256*s->y_dc_scale){
1710                 fprintf(stderr, "dc overflow+ L qscale: %d//\n", s->qscale);
1711                 if(!s->inter_intra_pred) return -1;
1712             }
1713         } else {
1714             rl = &rl_table[3 + s->rl_chroma_table_index];
1715             if(level > 256*s->c_dc_scale){
1716                 fprintf(stderr, "dc overflow+ C qscale: %d//\n", s->qscale);
1717                 if(!s->inter_intra_pred) return -1;
1718             }
1719         }
1720         block[0] = level;
1721
1722         run_diff = 0;
1723         i = 0;
1724         if (!coded) {
1725             goto not_coded;
1726         }
1727         if (s->ac_pred) {
1728             if (dc_pred_dir == 0) 
1729                 scan_table = s->intra_v_scantable.permutated; /* left */
1730             else
1731                 scan_table = s->intra_h_scantable.permutated; /* top */
1732         } else {
1733             scan_table = s->intra_scantable.permutated;
1734         }
1735         set_stat(ST_INTRA_AC);
1736         rl_vlc= rl->rl_vlc[0];
1737     } else {
1738         qmul = s->qscale << 1;
1739         qadd = (s->qscale - 1) | 1;
1740         i = -1;
1741         rl = &rl_table[3 + s->rl_table_index];
1742
1743         if(s->msmpeg4_version==2)
1744             run_diff = 0;
1745         else
1746             run_diff = 1;
1747
1748         if (!coded) {
1749             s->block_last_index[n] = i;
1750             return 0;
1751         }
1752         if(!scan_table)
1753             scan_table = s->inter_scantable.permutated;
1754         set_stat(ST_INTER_AC);
1755         rl_vlc= rl->rl_vlc[s->qscale];
1756     }
1757   {
1758     OPEN_READER(re, &s->gb);
1759     for(;;) {
1760         UPDATE_CACHE(re, &s->gb);
1761         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2);
1762         if (level==0) {
1763             int cache;
1764             cache= GET_CACHE(re, &s->gb);
1765             /* escape */
1766             if (s->msmpeg4_version==1 || (cache&0x80000000)==0) {
1767                 if (s->msmpeg4_version==1 || (cache&0x40000000)==0) {
1768                     /* third escape */
1769                     if(s->msmpeg4_version!=1) LAST_SKIP_BITS(re, &s->gb, 2);
1770                     UPDATE_CACHE(re, &s->gb);
1771                     if(s->msmpeg4_version<=3){
1772                         last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
1773                         run=   SHOW_UBITS(re, &s->gb, 6); SKIP_CACHE(re, &s->gb, 6);
1774                         level= SHOW_SBITS(re, &s->gb, 8); LAST_SKIP_CACHE(re, &s->gb, 8);
1775                         SKIP_COUNTER(re, &s->gb, 1+6+8);
1776                     }else{                        
1777                         int sign;
1778                         last=  SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
1779                         if(!s->esc3_level_length){
1780                             int ll;
1781                             //printf("ESC-3 %X at %d %d\n", show_bits(&s->gb, 24), s->mb_x, s->mb_y);
1782                             if(s->qscale<8){
1783                                 ll= SHOW_UBITS(re, &s->gb, 3); SKIP_BITS(re, &s->gb, 3);
1784                                 if(ll==0){
1785                                     if(SHOW_UBITS(re, &s->gb, 1)) printf("cool a new vlc code ,contact the ffmpeg developers and upload the file\n");
1786                                     SKIP_BITS(re, &s->gb, 1);
1787                                     ll=8;
1788                                 }
1789                             }else{
1790                                 ll=2;
1791                                 while(ll<8 && SHOW_UBITS(re, &s->gb, 1)==0){
1792                                     ll++;
1793                                     SKIP_BITS(re, &s->gb, 1);
1794                                 }
1795                                 if(ll<8) SKIP_BITS(re, &s->gb, 1);
1796                             }
1797
1798                             s->esc3_level_length= ll;
1799                             s->esc3_run_length= SHOW_UBITS(re, &s->gb, 2) + 3; SKIP_BITS(re, &s->gb, 2);
1800 //printf("level length:%d, run length: %d\n", ll, s->esc3_run_length);
1801                             UPDATE_CACHE(re, &s->gb);
1802                         }
1803                         run=   SHOW_UBITS(re, &s->gb, s->esc3_run_length); 
1804                         SKIP_BITS(re, &s->gb, s->esc3_run_length);
1805                         
1806                         sign=  SHOW_UBITS(re, &s->gb, 1); 
1807                         SKIP_BITS(re, &s->gb, 1);
1808                         
1809                         level= SHOW_UBITS(re, &s->gb, s->esc3_level_length); 
1810                         SKIP_BITS(re, &s->gb, s->esc3_level_length);
1811                         if(sign) level= -level;
1812                     }
1813 //printf("level: %d, run: %d at %d %d\n", level, run, s->mb_x, s->mb_y);
1814 #if 0 // waste of time / this will detect very few errors
1815                     {
1816                         const int abs_level= ABS(level);
1817                         const int run1= run - rl->max_run[last][abs_level] - run_diff;
1818                         if(abs_level<=MAX_LEVEL && run<=MAX_RUN){
1819                             if(abs_level <= rl->max_level[last][run]){
1820                                 fprintf(stderr, "illegal 3. esc, vlc encoding possible\n");
1821                                 return DECODING_AC_LOST;
1822                             }
1823                             if(abs_level <= rl->max_level[last][run]*2){
1824                                 fprintf(stderr, "illegal 3. esc, esc 1 encoding possible\n");
1825                                 return DECODING_AC_LOST;
1826                             }
1827                             if(run1>=0 && abs_level <= rl->max_level[last][run1]){
1828                                 fprintf(stderr, "illegal 3. esc, esc 2 encoding possible\n");
1829                                 return DECODING_AC_LOST;
1830                             }
1831                         }
1832                     }
1833 #endif
1834                     //level = level * qmul + (level>0) * qadd - (level<=0) * qadd ;
1835                     if (level>0) level= level * qmul + qadd;
1836                     else         level= level * qmul - qadd;
1837 #if 0 // waste of time too :(
1838                     if(level>2048 || level<-2048){
1839                         fprintf(stderr, "|level| overflow in 3. esc\n");
1840                         return DECODING_AC_LOST;
1841                     }
1842 #endif
1843                     i+= run + 1;
1844                     if(last) i+=192;
1845 #ifdef ERROR_DETAILS
1846                 if(run==66)
1847                     fprintf(stderr, "illegal vlc code in ESC3 level=%d\n", level);
1848                 else if((i>62 && i<192) || i>192+63)
1849                     fprintf(stderr, "run overflow in ESC3 i=%d run=%d level=%d\n", i, run, level);
1850 #endif
1851                 } else {
1852                     /* second escape */
1853 #if MIN_CACHE_BITS < 23
1854                     LAST_SKIP_BITS(re, &s->gb, 2);
1855                     UPDATE_CACHE(re, &s->gb);
1856 #else
1857                     SKIP_BITS(re, &s->gb, 2);
1858 #endif
1859                     GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2);
1860                     i+= run + rl->max_run[run>>7][level/qmul] + run_diff; //FIXME opt indexing
1861                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1862                     LAST_SKIP_BITS(re, &s->gb, 1);
1863 #ifdef ERROR_DETAILS
1864                 if(run==66)
1865                     fprintf(stderr, "illegal vlc code in ESC2 level=%d\n", level);
1866                 else if((i>62 && i<192) || i>192+63)
1867                     fprintf(stderr, "run overflow in ESC2 i=%d run=%d level=%d\n", i, run, level);
1868 #endif
1869                 }
1870             } else {
1871                 /* first escape */
1872 #if MIN_CACHE_BITS < 22
1873                 LAST_SKIP_BITS(re, &s->gb, 1);
1874                 UPDATE_CACHE(re, &s->gb);
1875 #else
1876                 SKIP_BITS(re, &s->gb, 1);
1877 #endif
1878                 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2);
1879                 i+= run;
1880                 level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
1881                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1882                 LAST_SKIP_BITS(re, &s->gb, 1);
1883 #ifdef ERROR_DETAILS
1884                 if(run==66)
1885                     fprintf(stderr, "illegal vlc code in ESC1 level=%d\n", level);
1886                 else if((i>62 && i<192) || i>192+63)
1887                     fprintf(stderr, "run overflow in ESC1 i=%d run=%d level=%d\n", i, run, level);
1888 #endif
1889             }
1890         } else {
1891             i+= run;
1892             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1893             LAST_SKIP_BITS(re, &s->gb, 1);
1894 #ifdef ERROR_DETAILS
1895                 if(run==66)
1896                     fprintf(stderr, "illegal vlc code level=%d\n", level);
1897                 else if((i>62 && i<192) || i>192+63)
1898                     fprintf(stderr, "run overflow i=%d run=%d level=%d\n", i, run, level);
1899 #endif
1900         }
1901         if (i > 62){
1902             i-= 192;
1903             if(i&(~63)){
1904                 const int left= s->gb.size_in_bits - get_bits_count(&s->gb);
1905                 if(((i+192 == 64 && level/qmul==-1) || s->error_resilience<=1) && left>=0){
1906                     fprintf(stderr, "ignoring overflow at %d %d\n", s->mb_x, s->mb_y);
1907                     break;
1908                 }else{
1909                     fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1910                     return -1;
1911                 }
1912             }
1913
1914             block[scan_table[i]] = level;
1915             break;
1916         }
1917
1918         block[scan_table[i]] = level;
1919     }
1920     CLOSE_READER(re, &s->gb);
1921   }
1922  not_coded:
1923     if (s->mb_intra) {
1924         mpeg4_pred_ac(s, block, n, dc_pred_dir);
1925         if (s->ac_pred) {
1926             i = 63; /* XXX: not optimal */
1927         }
1928     }
1929     if(s->msmpeg4_version>=4 && i>0) i=63; //FIXME/XXX optimize
1930     s->block_last_index[n] = i;
1931     
1932     return 0;
1933 }
1934
1935 static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
1936 {
1937     int level, pred;
1938
1939     if(s->msmpeg4_version<=2){
1940         if (n < 4) {
1941             level = get_vlc2(&s->gb, v2_dc_lum_vlc.table, DC_VLC_BITS, 3);
1942         } else {
1943             level = get_vlc2(&s->gb, v2_dc_chroma_vlc.table, DC_VLC_BITS, 3);
1944         }
1945         if (level < 0) 
1946             return -1;
1947         level-=256;
1948     }else{  //FIXME optimize use unified tables & index
1949         if (n < 4) {
1950             level = get_vlc2(&s->gb, dc_lum_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
1951         } else {
1952             level = get_vlc2(&s->gb, dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
1953         }
1954         if (level < 0){
1955             fprintf(stderr, "illegal dc vlc\n");
1956             return -1;
1957         }
1958
1959         if (level == DC_MAX) {
1960             level = get_bits(&s->gb, 8);
1961             if (get_bits1(&s->gb))
1962                 level = -level;
1963         } else if (level != 0) {
1964             if (get_bits1(&s->gb))
1965                 level = -level;
1966         }
1967     }
1968
1969     if(s->msmpeg4_version==1){
1970         int32_t *dc_val;
1971         pred = msmpeg4v1_pred_dc(s, n, &dc_val);
1972         level += pred;
1973         
1974         /* update predictor */
1975         *dc_val= level;
1976     }else{
1977         uint16_t *dc_val;
1978         pred = msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
1979         level += pred;
1980
1981         /* update predictor */
1982         if (n < 4) {
1983             *dc_val = level * s->y_dc_scale;
1984         } else {
1985             *dc_val = level * s->c_dc_scale;
1986         }
1987     }
1988
1989     return level;
1990 }
1991
1992 static int msmpeg4_decode_motion(MpegEncContext * s, 
1993                                  int *mx_ptr, int *my_ptr)
1994 {
1995     MVTable *mv;
1996     int code, mx, my;
1997
1998     mv = &mv_tables[s->mv_table_index];
1999
2000     code = get_vlc2(&s->gb, mv->vlc.table, MV_VLC_BITS, 2);
2001     if (code < 0){
2002         fprintf(stderr, "illegal MV code at %d %d\n", s->mb_x, s->mb_y);
2003         return -1;
2004     }
2005     if (code == mv->n) {
2006 //printf("MV ESC %X at %d %d\n", show_bits(&s->gb, 24), s->mb_x, s->mb_y);
2007         mx = get_bits(&s->gb, 6);
2008         my = get_bits(&s->gb, 6);
2009     } else {
2010         mx = mv->table_mvx[code];
2011         my = mv->table_mvy[code];
2012     }
2013
2014     mx += *mx_ptr - 32;
2015     my += *my_ptr - 32;
2016     /* WARNING : they do not do exactly modulo encoding */
2017     if (mx <= -64)
2018         mx += 64;
2019     else if (mx >= 64)
2020         mx -= 64;
2021
2022     if (my <= -64)
2023         my += 64;
2024     else if (my >= 64)
2025         my -= 64;
2026     *mx_ptr = mx;
2027     *my_ptr = my;
2028     return 0;
2029 }
2030
2031 /* cleanest way to support it
2032  * there is too much shared between versions so that we cant have 1 file per version & 1 common
2033  * as allmost everything would be in the common file 
2034  */
2035 #include "wmv2.c"