2fc2de1968058ffa46b446ad3b65d63fc5c4a4e4
[ffmpeg.git] / libavcodec / msmpeg4dec.c
1 /*
2  * MSMPEG4 backend for encoder and decoder
3  * Copyright (c) 2001 Fabrice Bellard
4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * msmpeg4v1 & v2 stuff by Michael Niedermayer <michaelni@gmx.at>
7  *
8  * This file is part of Libav.
9  *
10  * Libav is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * Libav is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with Libav; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24
25 #include "avcodec.h"
26 #include "internal.h"
27 #include "mpegutils.h"
28 #include "mpegvideo.h"
29 #include "msmpeg4.h"
30 #include "libavutil/x86/asm.h"
31 #include "h263.h"
32 #include "mpeg4video.h"
33 #include "msmpeg4data.h"
34 #include "vc1data.h"
35
36 #define DC_VLC_BITS 9
37 #define V2_INTRA_CBPC_VLC_BITS 3
38 #define V2_MB_TYPE_VLC_BITS 7
39 #define MV_VLC_BITS 9
40 #define V2_MV_VLC_BITS 9
41 #define TEX_VLC_BITS 9
42
43 #define DEFAULT_INTER_INDEX 3
44
45 static inline int msmpeg4v1_pred_dc(MpegEncContext * s, int n,
46                                     int32_t **dc_val_ptr)
47 {
48     int i;
49
50     if (n < 4) {
51         i= 0;
52     } else {
53         i= n-3;
54     }
55
56     *dc_val_ptr= &s->last_dc[i];
57     return s->last_dc[i];
58 }
59
60 /****************************************/
61 /* decoding stuff */
62
63 VLC ff_mb_non_intra_vlc[4];
64 static VLC v2_dc_lum_vlc;
65 static VLC v2_dc_chroma_vlc;
66 static VLC v2_intra_cbpc_vlc;
67 static VLC v2_mb_type_vlc;
68 static VLC v2_mv_vlc;
69 VLC ff_inter_intra_vlc;
70
71 /* This is identical to h263 except that its range is multiplied by 2. */
72 static int msmpeg4v2_decode_motion(MpegEncContext * s, int pred, int f_code)
73 {
74     int code, val, sign, shift;
75
76     code = get_vlc2(&s->gb, v2_mv_vlc.table, V2_MV_VLC_BITS, 2);
77     ff_dlog(s, "MV code %d at %d %d pred: %d\n", code, s->mb_x,s->mb_y, pred);
78     if (code < 0)
79         return 0xffff;
80
81     if (code == 0)
82         return pred;
83     sign = get_bits1(&s->gb);
84     shift = f_code - 1;
85     val = code;
86     if (shift) {
87         val = (val - 1) << shift;
88         val |= get_bits(&s->gb, shift);
89         val++;
90     }
91     if (sign)
92         val = -val;
93
94     val += pred;
95     if (val <= -64)
96         val += 64;
97     else if (val >= 64)
98         val -= 64;
99
100     return val;
101 }
102
103 static int msmpeg4v12_decode_mb(MpegEncContext *s, int16_t block[6][64])
104 {
105     int cbp, code, i;
106
107     if (s->pict_type == AV_PICTURE_TYPE_P) {
108         if (s->use_skip_mb_code) {
109             if (get_bits1(&s->gb)) {
110                 /* skip mb */
111                 s->mb_intra = 0;
112                 for(i=0;i<6;i++)
113                     s->block_last_index[i] = -1;
114                 s->mv_dir = MV_DIR_FORWARD;
115                 s->mv_type = MV_TYPE_16X16;
116                 s->mv[0][0][0] = 0;
117                 s->mv[0][0][1] = 0;
118                 s->mb_skipped = 1;
119                 return 0;
120             }
121         }
122
123         if(s->msmpeg4_version==2)
124             code = get_vlc2(&s->gb, v2_mb_type_vlc.table, V2_MB_TYPE_VLC_BITS, 1);
125         else
126             code = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
127         if(code<0 || code>7){
128             av_log(s->avctx, AV_LOG_ERROR, "cbpc %d invalid at %d %d\n", code, s->mb_x, s->mb_y);
129             return -1;
130         }
131
132         s->mb_intra = code >>2;
133
134         cbp = code & 0x3;
135     } else {
136         s->mb_intra = 1;
137         if(s->msmpeg4_version==2)
138             cbp= get_vlc2(&s->gb, v2_intra_cbpc_vlc.table, V2_INTRA_CBPC_VLC_BITS, 1);
139         else
140             cbp= get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 1);
141         if(cbp<0 || cbp>3){
142             av_log(s->avctx, AV_LOG_ERROR, "cbpc %d invalid at %d %d\n", cbp, s->mb_x, s->mb_y);
143             return -1;
144         }
145     }
146
147     if (!s->mb_intra) {
148         int mx, my, cbpy;
149
150         cbpy= get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
151         if(cbpy<0){
152             av_log(s->avctx, AV_LOG_ERROR, "cbpy %d invalid at %d %d\n", cbp, s->mb_x, s->mb_y);
153             return -1;
154         }
155
156         cbp|= cbpy<<2;
157         if(s->msmpeg4_version==1 || (cbp&3) != 3) cbp^= 0x3C;
158
159         ff_h263_pred_motion(s, 0, 0, &mx, &my);
160         mx= msmpeg4v2_decode_motion(s, mx, 1);
161         my= msmpeg4v2_decode_motion(s, my, 1);
162
163         s->mv_dir = MV_DIR_FORWARD;
164         s->mv_type = MV_TYPE_16X16;
165         s->mv[0][0][0] = mx;
166         s->mv[0][0][1] = my;
167     } else {
168         if(s->msmpeg4_version==2){
169             s->ac_pred = get_bits1(&s->gb);
170             cbp|= get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1)<<2; //FIXME check errors
171         } else{
172             s->ac_pred = 0;
173             cbp|= get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1)<<2; //FIXME check errors
174             if(s->pict_type==AV_PICTURE_TYPE_P) cbp^=0x3C;
175         }
176     }
177
178     s->bdsp.clear_blocks(s->block[0]);
179     for (i = 0; i < 6; i++) {
180         if (ff_msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
181         {
182              av_log(s->avctx, AV_LOG_ERROR, "\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
183              return -1;
184         }
185     }
186     return 0;
187 }
188
189 static int msmpeg4v34_decode_mb(MpegEncContext *s, int16_t block[6][64])
190 {
191     int cbp, code, i;
192     uint8_t *coded_val;
193     uint32_t * const mb_type_ptr = &s->current_picture.mb_type[s->mb_x + s->mb_y*s->mb_stride];
194
195     if (s->pict_type == AV_PICTURE_TYPE_P) {
196         if (s->use_skip_mb_code) {
197             if (get_bits1(&s->gb)) {
198                 /* skip mb */
199                 s->mb_intra = 0;
200                 for(i=0;i<6;i++)
201                     s->block_last_index[i] = -1;
202                 s->mv_dir = MV_DIR_FORWARD;
203                 s->mv_type = MV_TYPE_16X16;
204                 s->mv[0][0][0] = 0;
205                 s->mv[0][0][1] = 0;
206                 s->mb_skipped = 1;
207                 *mb_type_ptr = MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
208
209                 return 0;
210             }
211         }
212
213         code = get_vlc2(&s->gb, ff_mb_non_intra_vlc[DEFAULT_INTER_INDEX].table, MB_NON_INTRA_VLC_BITS, 3);
214         if (code < 0)
215             return -1;
216         //s->mb_intra = (code & 0x40) ? 0 : 1;
217         s->mb_intra = (~code & 0x40) >> 6;
218
219         cbp = code & 0x3f;
220     } else {
221         s->mb_intra = 1;
222         code = get_vlc2(&s->gb, ff_msmp4_mb_i_vlc.table, MB_INTRA_VLC_BITS, 2);
223         if (code < 0)
224             return -1;
225         /* predict coded block pattern */
226         cbp = 0;
227         for(i=0;i<6;i++) {
228             int val = ((code >> (5 - i)) & 1);
229             if (i < 4) {
230                 int pred = ff_msmpeg4_coded_block_pred(s, i, &coded_val);
231                 val = val ^ pred;
232                 *coded_val = val;
233             }
234             cbp |= val << (5 - i);
235         }
236     }
237
238     if (!s->mb_intra) {
239         int mx, my;
240         if(s->per_mb_rl_table && cbp){
241             s->rl_table_index = decode012(&s->gb);
242             s->rl_chroma_table_index = s->rl_table_index;
243         }
244         ff_h263_pred_motion(s, 0, 0, &mx, &my);
245         if (ff_msmpeg4_decode_motion(s, &mx, &my) < 0)
246             return -1;
247         s->mv_dir = MV_DIR_FORWARD;
248         s->mv_type = MV_TYPE_16X16;
249         s->mv[0][0][0] = mx;
250         s->mv[0][0][1] = my;
251         *mb_type_ptr = MB_TYPE_L0 | MB_TYPE_16x16;
252     } else {
253         ff_dlog(s, "I at %d %d %d %06X\n", s->mb_x, s->mb_y,
254                 ((cbp & 3) ? 1 : 0) +((cbp & 0x3C)? 2 : 0),
255                 show_bits(&s->gb, 24));
256         s->ac_pred = get_bits1(&s->gb);
257         *mb_type_ptr = MB_TYPE_INTRA;
258         if(s->inter_intra_pred){
259             s->h263_aic_dir= get_vlc2(&s->gb, ff_inter_intra_vlc.table, INTER_INTRA_VLC_BITS, 1);
260             ff_dlog(s, "%d%d %d %d/",
261                     s->ac_pred, s->h263_aic_dir, s->mb_x, s->mb_y);
262         }
263         if(s->per_mb_rl_table && cbp){
264             s->rl_table_index = decode012(&s->gb);
265             s->rl_chroma_table_index = s->rl_table_index;
266         }
267     }
268
269     s->bdsp.clear_blocks(s->block[0]);
270     for (i = 0; i < 6; i++) {
271         if (ff_msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
272         {
273             av_log(s->avctx, AV_LOG_ERROR, "\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
274             return -1;
275         }
276     }
277
278     return 0;
279 }
280
281 /* init all vlc decoding tables */
282 av_cold int ff_msmpeg4_decode_init(AVCodecContext *avctx)
283 {
284     MpegEncContext *s = avctx->priv_data;
285     static int done = 0;
286     int i;
287     MVTable *mv;
288
289     if (ff_h263_decode_init(avctx) < 0)
290         return -1;
291
292     ff_msmpeg4_common_init(s);
293
294     if (!done) {
295         done = 1;
296
297         for(i=0;i<NB_RL_TABLES;i++) {
298             ff_rl_init(&ff_rl_table[i], ff_static_rl_table_store[i]);
299         }
300         INIT_VLC_RL(ff_rl_table[0], 642);
301         INIT_VLC_RL(ff_rl_table[1], 1104);
302         INIT_VLC_RL(ff_rl_table[2], 554);
303         INIT_VLC_RL(ff_rl_table[3], 940);
304         INIT_VLC_RL(ff_rl_table[4], 962);
305         INIT_VLC_RL(ff_rl_table[5], 554);
306
307         mv = &ff_mv_tables[0];
308         INIT_VLC_STATIC(&mv->vlc, MV_VLC_BITS, mv->n + 1,
309                     mv->table_mv_bits, 1, 1,
310                     mv->table_mv_code, 2, 2, 3714);
311         mv = &ff_mv_tables[1];
312         INIT_VLC_STATIC(&mv->vlc, MV_VLC_BITS, mv->n + 1,
313                     mv->table_mv_bits, 1, 1,
314                     mv->table_mv_code, 2, 2, 2694);
315
316         INIT_VLC_STATIC(&ff_msmp4_dc_luma_vlc[0], DC_VLC_BITS, 120,
317                  &ff_table0_dc_lum[0][1], 8, 4,
318                  &ff_table0_dc_lum[0][0], 8, 4, 1158);
319         INIT_VLC_STATIC(&ff_msmp4_dc_chroma_vlc[0], DC_VLC_BITS, 120,
320                  &ff_table0_dc_chroma[0][1], 8, 4,
321                  &ff_table0_dc_chroma[0][0], 8, 4, 1118);
322         INIT_VLC_STATIC(&ff_msmp4_dc_luma_vlc[1], DC_VLC_BITS, 120,
323                  &ff_table1_dc_lum[0][1], 8, 4,
324                  &ff_table1_dc_lum[0][0], 8, 4, 1476);
325         INIT_VLC_STATIC(&ff_msmp4_dc_chroma_vlc[1], DC_VLC_BITS, 120,
326                  &ff_table1_dc_chroma[0][1], 8, 4,
327                  &ff_table1_dc_chroma[0][0], 8, 4, 1216);
328
329         INIT_VLC_STATIC(&v2_dc_lum_vlc, DC_VLC_BITS, 512,
330                  &ff_v2_dc_lum_table[0][1], 8, 4,
331                  &ff_v2_dc_lum_table[0][0], 8, 4, 1472);
332         INIT_VLC_STATIC(&v2_dc_chroma_vlc, DC_VLC_BITS, 512,
333                  &ff_v2_dc_chroma_table[0][1], 8, 4,
334                  &ff_v2_dc_chroma_table[0][0], 8, 4, 1506);
335
336         INIT_VLC_STATIC(&v2_intra_cbpc_vlc, V2_INTRA_CBPC_VLC_BITS, 4,
337                  &ff_v2_intra_cbpc[0][1], 2, 1,
338                  &ff_v2_intra_cbpc[0][0], 2, 1, 8);
339         INIT_VLC_STATIC(&v2_mb_type_vlc, V2_MB_TYPE_VLC_BITS, 8,
340                  &ff_v2_mb_type[0][1], 2, 1,
341                  &ff_v2_mb_type[0][0], 2, 1, 128);
342         INIT_VLC_STATIC(&v2_mv_vlc, V2_MV_VLC_BITS, 33,
343                  &ff_mvtab[0][1], 2, 1,
344                  &ff_mvtab[0][0], 2, 1, 538);
345
346         INIT_VLC_STATIC(&ff_mb_non_intra_vlc[0], MB_NON_INTRA_VLC_BITS, 128,
347                      &ff_wmv2_inter_table[0][0][1], 8, 4,
348                      &ff_wmv2_inter_table[0][0][0], 8, 4, 1636);
349         INIT_VLC_STATIC(&ff_mb_non_intra_vlc[1], MB_NON_INTRA_VLC_BITS, 128,
350                      &ff_wmv2_inter_table[1][0][1], 8, 4,
351                      &ff_wmv2_inter_table[1][0][0], 8, 4, 2648);
352         INIT_VLC_STATIC(&ff_mb_non_intra_vlc[2], MB_NON_INTRA_VLC_BITS, 128,
353                      &ff_wmv2_inter_table[2][0][1], 8, 4,
354                      &ff_wmv2_inter_table[2][0][0], 8, 4, 1532);
355         INIT_VLC_STATIC(&ff_mb_non_intra_vlc[3], MB_NON_INTRA_VLC_BITS, 128,
356                      &ff_wmv2_inter_table[3][0][1], 8, 4,
357                      &ff_wmv2_inter_table[3][0][0], 8, 4, 2488);
358
359         INIT_VLC_STATIC(&ff_msmp4_mb_i_vlc, MB_INTRA_VLC_BITS, 64,
360                  &ff_msmp4_mb_i_table[0][1], 4, 2,
361                  &ff_msmp4_mb_i_table[0][0], 4, 2, 536);
362
363         INIT_VLC_STATIC(&ff_inter_intra_vlc, INTER_INTRA_VLC_BITS, 4,
364                  &ff_table_inter_intra[0][1], 2, 1,
365                  &ff_table_inter_intra[0][0], 2, 1, 8);
366     }
367
368     switch(s->msmpeg4_version){
369     case 1:
370     case 2:
371         s->decode_mb= msmpeg4v12_decode_mb;
372         break;
373     case 3:
374     case 4:
375         s->decode_mb= msmpeg4v34_decode_mb;
376         break;
377     case 5:
378         if (CONFIG_WMV2_DECODER)
379             s->decode_mb= ff_wmv2_decode_mb;
380     case 6:
381         //FIXME + TODO VC1 decode mb
382         break;
383     }
384
385     s->slice_height= s->mb_height; //to avoid 1/0 if the first frame is not a keyframe
386
387     return 0;
388 }
389
390 int ff_msmpeg4_decode_picture_header(MpegEncContext * s)
391 {
392     int code;
393
394     if(s->msmpeg4_version==1){
395         int start_code = get_bits_long(&s->gb, 32);
396         if(start_code!=0x00000100){
397             av_log(s->avctx, AV_LOG_ERROR, "invalid startcode\n");
398             return -1;
399         }
400
401         skip_bits(&s->gb, 5); // frame number */
402     }
403
404     s->pict_type = get_bits(&s->gb, 2) + 1;
405     if (s->pict_type != AV_PICTURE_TYPE_I &&
406         s->pict_type != AV_PICTURE_TYPE_P){
407         av_log(s->avctx, AV_LOG_ERROR, "invalid picture type\n");
408         return -1;
409     }
410 #if 0
411 {
412     static int had_i=0;
413     if(s->pict_type == AV_PICTURE_TYPE_I) had_i=1;
414     if(!had_i) return -1;
415 }
416 #endif
417     s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
418     if(s->qscale==0){
419         av_log(s->avctx, AV_LOG_ERROR, "invalid qscale\n");
420         return -1;
421     }
422
423     if (s->pict_type == AV_PICTURE_TYPE_I) {
424         code = get_bits(&s->gb, 5);
425         if(s->msmpeg4_version==1){
426             if(code==0 || code>s->mb_height){
427                 av_log(s->avctx, AV_LOG_ERROR, "invalid slice height %d\n", code);
428                 return -1;
429             }
430
431             s->slice_height = code;
432         }else{
433             /* 0x17: one slice, 0x18: two slices, ... */
434             if (code < 0x17){
435                 av_log(s->avctx, AV_LOG_ERROR, "error, slice code was %X\n", code);
436                 return -1;
437             }
438
439             s->slice_height = s->mb_height / (code - 0x16);
440         }
441
442         switch(s->msmpeg4_version){
443         case 1:
444         case 2:
445             s->rl_chroma_table_index = 2;
446             s->rl_table_index = 2;
447
448             s->dc_table_index = 0; //not used
449             break;
450         case 3:
451             s->rl_chroma_table_index = decode012(&s->gb);
452             s->rl_table_index = decode012(&s->gb);
453
454             s->dc_table_index = get_bits1(&s->gb);
455             break;
456         case 4:
457             ff_msmpeg4_decode_ext_header(s, (2+5+5+17+7)/8);
458
459             if(s->bit_rate > MBAC_BITRATE) s->per_mb_rl_table= get_bits1(&s->gb);
460             else                           s->per_mb_rl_table= 0;
461
462             if(!s->per_mb_rl_table){
463                 s->rl_chroma_table_index = decode012(&s->gb);
464                 s->rl_table_index = decode012(&s->gb);
465             }
466
467             s->dc_table_index = get_bits1(&s->gb);
468             s->inter_intra_pred= 0;
469             break;
470         }
471         s->no_rounding = 1;
472         if(s->avctx->debug&FF_DEBUG_PICT_INFO)
473             av_log(s->avctx, AV_LOG_DEBUG, "qscale:%d rlc:%d rl:%d dc:%d mbrl:%d slice:%d   \n",
474                 s->qscale,
475                 s->rl_chroma_table_index,
476                 s->rl_table_index,
477                 s->dc_table_index,
478                 s->per_mb_rl_table,
479                 s->slice_height);
480     } else {
481         switch(s->msmpeg4_version){
482         case 1:
483         case 2:
484             if(s->msmpeg4_version==1)
485                 s->use_skip_mb_code = 1;
486             else
487                 s->use_skip_mb_code = get_bits1(&s->gb);
488             s->rl_table_index = 2;
489             s->rl_chroma_table_index = s->rl_table_index;
490             s->dc_table_index = 0; //not used
491             s->mv_table_index = 0;
492             break;
493         case 3:
494             s->use_skip_mb_code = get_bits1(&s->gb);
495             s->rl_table_index = decode012(&s->gb);
496             s->rl_chroma_table_index = s->rl_table_index;
497
498             s->dc_table_index = get_bits1(&s->gb);
499
500             s->mv_table_index = get_bits1(&s->gb);
501             break;
502         case 4:
503             s->use_skip_mb_code = get_bits1(&s->gb);
504
505             if(s->bit_rate > MBAC_BITRATE) s->per_mb_rl_table= get_bits1(&s->gb);
506             else                           s->per_mb_rl_table= 0;
507
508             if(!s->per_mb_rl_table){
509                 s->rl_table_index = decode012(&s->gb);
510                 s->rl_chroma_table_index = s->rl_table_index;
511             }
512
513             s->dc_table_index = get_bits1(&s->gb);
514
515             s->mv_table_index = get_bits1(&s->gb);
516             s->inter_intra_pred= (s->width*s->height < 320*240 && s->bit_rate<=II_BITRATE);
517             break;
518         }
519
520         if(s->avctx->debug&FF_DEBUG_PICT_INFO)
521             av_log(s->avctx, AV_LOG_DEBUG, "skip:%d rl:%d rlc:%d dc:%d mv:%d mbrl:%d qp:%d   \n",
522                 s->use_skip_mb_code,
523                 s->rl_table_index,
524                 s->rl_chroma_table_index,
525                 s->dc_table_index,
526                 s->mv_table_index,
527                 s->per_mb_rl_table,
528                 s->qscale);
529
530         if(s->flipflop_rounding){
531             s->no_rounding ^= 1;
532         }else{
533             s->no_rounding = 0;
534         }
535     }
536     ff_dlog(s->avctx, "%d %d %d %d %d\n", s->pict_type, s->bit_rate,
537             s->inter_intra_pred, s->width, s->height);
538
539     s->esc3_level_length= 0;
540     s->esc3_run_length= 0;
541
542     return 0;
543 }
544
545 int ff_msmpeg4_decode_ext_header(MpegEncContext * s, int buf_size)
546 {
547     int left= buf_size*8 - get_bits_count(&s->gb);
548     int length= s->msmpeg4_version>=3 ? 17 : 16;
549     /* the alt_bitstream reader could read over the end so we need to check it */
550     if(left>=length && left<length+8)
551     {
552         skip_bits(&s->gb, 5); /* fps */
553         s->bit_rate= get_bits(&s->gb, 11)*1024;
554         if(s->msmpeg4_version>=3)
555             s->flipflop_rounding= get_bits1(&s->gb);
556         else
557             s->flipflop_rounding= 0;
558     }
559     else if(left<length+8)
560     {
561         s->flipflop_rounding= 0;
562         if(s->msmpeg4_version != 2)
563             av_log(s->avctx, AV_LOG_ERROR, "ext header missing, %d left\n", left);
564     }
565     else
566     {
567         av_log(s->avctx, AV_LOG_ERROR, "I frame too long, ignoring ext header\n");
568     }
569
570     return 0;
571 }
572
573 static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
574 {
575     int level, pred;
576
577     if(s->msmpeg4_version<=2){
578         if (n < 4) {
579             level = get_vlc2(&s->gb, v2_dc_lum_vlc.table, DC_VLC_BITS, 3);
580         } else {
581             level = get_vlc2(&s->gb, v2_dc_chroma_vlc.table, DC_VLC_BITS, 3);
582         }
583         if (level < 0)
584             return -1;
585         level-=256;
586     }else{  //FIXME optimize use unified tables & index
587         if (n < 4) {
588             level = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
589         } else {
590             level = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
591         }
592         if (level < 0){
593             av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
594             return -1;
595         }
596
597         if (level == DC_MAX) {
598             level = get_bits(&s->gb, 8);
599             if (get_bits1(&s->gb))
600                 level = -level;
601         } else if (level != 0) {
602             if (get_bits1(&s->gb))
603                 level = -level;
604         }
605     }
606
607     if(s->msmpeg4_version==1){
608         int32_t *dc_val;
609         pred = msmpeg4v1_pred_dc(s, n, &dc_val);
610         level += pred;
611
612         /* update predictor */
613         *dc_val= level;
614     }else{
615         int16_t *dc_val;
616         pred   = ff_msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
617         level += pred;
618
619         /* update predictor */
620         if (n < 4) {
621             *dc_val = level * s->y_dc_scale;
622         } else {
623             *dc_val = level * s->c_dc_scale;
624         }
625     }
626
627     return level;
628 }
629
630 //#define ERROR_DETAILS
631 int ff_msmpeg4_decode_block(MpegEncContext * s, int16_t * block,
632                               int n, int coded, const uint8_t *scan_table)
633 {
634     int level, i, last, run, run_diff;
635     int av_uninit(dc_pred_dir);
636     RLTable *rl;
637     RL_VLC_ELEM *rl_vlc;
638     int qmul, qadd;
639
640     if (s->mb_intra) {
641         qmul=1;
642         qadd=0;
643
644         /* DC coef */
645         level = msmpeg4_decode_dc(s, n, &dc_pred_dir);
646
647         if (level < 0){
648             av_log(s->avctx, AV_LOG_ERROR, "dc overflow- block: %d qscale: %d//\n", n, s->qscale);
649             if(s->inter_intra_pred) level=0;
650             else                    return -1;
651         }
652         if (n < 4) {
653             rl = &ff_rl_table[s->rl_table_index];
654             if(level > 256*s->y_dc_scale){
655                 av_log(s->avctx, AV_LOG_ERROR, "dc overflow+ L qscale: %d//\n", s->qscale);
656                 if(!s->inter_intra_pred) return -1;
657             }
658         } else {
659             rl = &ff_rl_table[3 + s->rl_chroma_table_index];
660             if(level > 256*s->c_dc_scale){
661                 av_log(s->avctx, AV_LOG_ERROR, "dc overflow+ C qscale: %d//\n", s->qscale);
662                 if(!s->inter_intra_pred) return -1;
663             }
664         }
665         block[0] = level;
666
667         run_diff = s->msmpeg4_version >= 4;
668         i = 0;
669         if (!coded) {
670             goto not_coded;
671         }
672         if (s->ac_pred) {
673             if (dc_pred_dir == 0)
674                 scan_table = s->intra_v_scantable.permutated; /* left */
675             else
676                 scan_table = s->intra_h_scantable.permutated; /* top */
677         } else {
678             scan_table = s->intra_scantable.permutated;
679         }
680         rl_vlc= rl->rl_vlc[0];
681     } else {
682         qmul = s->qscale << 1;
683         qadd = (s->qscale - 1) | 1;
684         i = -1;
685         rl = &ff_rl_table[3 + s->rl_table_index];
686
687         if(s->msmpeg4_version==2)
688             run_diff = 0;
689         else
690             run_diff = 1;
691
692         if (!coded) {
693             s->block_last_index[n] = i;
694             return 0;
695         }
696         if(!scan_table)
697             scan_table = s->inter_scantable.permutated;
698         rl_vlc= rl->rl_vlc[s->qscale];
699     }
700   {
701     OPEN_READER(re, &s->gb);
702     for(;;) {
703         UPDATE_CACHE(re, &s->gb);
704         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
705         if (level==0) {
706             int cache;
707             cache= GET_CACHE(re, &s->gb);
708             /* escape */
709             if (s->msmpeg4_version==1 || (cache&0x80000000)==0) {
710                 if (s->msmpeg4_version==1 || (cache&0x40000000)==0) {
711                     /* third escape */
712                     if(s->msmpeg4_version!=1) LAST_SKIP_BITS(re, &s->gb, 2);
713                     UPDATE_CACHE(re, &s->gb);
714                     if(s->msmpeg4_version<=3){
715                         last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
716                         run=   SHOW_UBITS(re, &s->gb, 6); SKIP_CACHE(re, &s->gb, 6);
717                         level= SHOW_SBITS(re, &s->gb, 8);
718                         SKIP_COUNTER(re, &s->gb, 1+6+8);
719                     }else{
720                         int sign;
721                         last=  SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
722                         if(!s->esc3_level_length){
723                             int ll;
724                             ff_dlog(s->avctx, "ESC-3 %X at %d %d\n",
725                                     show_bits(&s->gb, 24), s->mb_x, s->mb_y);
726                             if(s->qscale<8){
727                                 ll= SHOW_UBITS(re, &s->gb, 3); SKIP_BITS(re, &s->gb, 3);
728                                 if(ll==0){
729                                     ll= 8+SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
730                                 }
731                             }else{
732                                 ll=2;
733                                 while(ll<8 && SHOW_UBITS(re, &s->gb, 1)==0){
734                                     ll++;
735                                     SKIP_BITS(re, &s->gb, 1);
736                                 }
737                                 if(ll<8) SKIP_BITS(re, &s->gb, 1);
738                             }
739
740                             s->esc3_level_length= ll;
741                             s->esc3_run_length= SHOW_UBITS(re, &s->gb, 2) + 3; SKIP_BITS(re, &s->gb, 2);
742                             UPDATE_CACHE(re, &s->gb);
743                         }
744                         run=   SHOW_UBITS(re, &s->gb, s->esc3_run_length);
745                         SKIP_BITS(re, &s->gb, s->esc3_run_length);
746
747                         sign=  SHOW_UBITS(re, &s->gb, 1);
748                         SKIP_BITS(re, &s->gb, 1);
749
750                         level= SHOW_UBITS(re, &s->gb, s->esc3_level_length);
751                         SKIP_BITS(re, &s->gb, s->esc3_level_length);
752                         if(sign) level= -level;
753                     }
754
755 #if 0 // waste of time / this will detect very few errors
756                     {
757                         const int abs_level= FFABS(level);
758                         const int run1= run - rl->max_run[last][abs_level] - run_diff;
759                         if(abs_level<=MAX_LEVEL && run<=MAX_RUN){
760                             if(abs_level <= rl->max_level[last][run]){
761                                 av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
762                                 return DECODING_AC_LOST;
763                             }
764                             if(abs_level <= rl->max_level[last][run]*2){
765                                 av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
766                                 return DECODING_AC_LOST;
767                             }
768                             if(run1>=0 && abs_level <= rl->max_level[last][run1]){
769                                 av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
770                                 return DECODING_AC_LOST;
771                             }
772                         }
773                     }
774 #endif
775                     //level = level * qmul + (level>0) * qadd - (level<=0) * qadd ;
776                     if (level>0) level= level * qmul + qadd;
777                     else         level= level * qmul - qadd;
778 #if 0 // waste of time too :(
779                     if(level>2048 || level<-2048){
780                         av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc\n");
781                         return DECODING_AC_LOST;
782                     }
783 #endif
784                     i+= run + 1;
785                     if(last) i+=192;
786 #ifdef ERROR_DETAILS
787                 if(run==66)
788                     av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code in ESC3 level=%d\n", level);
789                 else if((i>62 && i<192) || i>192+63)
790                     av_log(s->avctx, AV_LOG_ERROR, "run overflow in ESC3 i=%d run=%d level=%d\n", i, run, level);
791 #endif
792                 } else {
793                     /* second escape */
794                     SKIP_BITS(re, &s->gb, 2);
795                     GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
796                     i+= run + rl->max_run[run>>7][level/qmul] + run_diff; //FIXME opt indexing
797                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
798                     LAST_SKIP_BITS(re, &s->gb, 1);
799 #ifdef ERROR_DETAILS
800                 if(run==66)
801                     av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code in ESC2 level=%d\n", level);
802                 else if((i>62 && i<192) || i>192+63)
803                     av_log(s->avctx, AV_LOG_ERROR, "run overflow in ESC2 i=%d run=%d level=%d\n", i, run, level);
804 #endif
805                 }
806             } else {
807                 /* first escape */
808                 SKIP_BITS(re, &s->gb, 1);
809                 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
810                 i+= run;
811                 level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
812                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
813                 LAST_SKIP_BITS(re, &s->gb, 1);
814 #ifdef ERROR_DETAILS
815                 if(run==66)
816                     av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code in ESC1 level=%d\n", level);
817                 else if((i>62 && i<192) || i>192+63)
818                     av_log(s->avctx, AV_LOG_ERROR, "run overflow in ESC1 i=%d run=%d level=%d\n", i, run, level);
819 #endif
820             }
821         } else {
822             i+= run;
823             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
824             LAST_SKIP_BITS(re, &s->gb, 1);
825 #ifdef ERROR_DETAILS
826                 if(run==66)
827                     av_log(s->avctx, AV_LOG_ERROR, "illegal vlc code level=%d\n", level);
828                 else if((i>62 && i<192) || i>192+63)
829                     av_log(s->avctx, AV_LOG_ERROR, "run overflow i=%d run=%d level=%d\n", i, run, level);
830 #endif
831         }
832         if (i > 62){
833             i-= 192;
834             if(i&(~63)){
835                 const int left= get_bits_left(&s->gb);
836                 if (((i + 192 == 64 && level / qmul == -1) ||
837                      !(s->avctx->err_recognition & AV_EF_BITSTREAM)) &&
838                     left >= 0) {
839                     av_log(s->avctx, AV_LOG_ERROR, "ignoring overflow at %d %d\n", s->mb_x, s->mb_y);
840                     break;
841                 }else{
842                     av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
843                     return -1;
844                 }
845             }
846
847             block[scan_table[i]] = level;
848             break;
849         }
850
851         block[scan_table[i]] = level;
852     }
853     CLOSE_READER(re, &s->gb);
854   }
855  not_coded:
856     if (s->mb_intra) {
857         ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
858         if (s->ac_pred) {
859             i = 63; /* XXX: not optimal */
860         }
861     }
862     if(s->msmpeg4_version>=4 && i>0) i=63; //FIXME/XXX optimize
863     s->block_last_index[n] = i;
864
865     return 0;
866 }
867
868 int ff_msmpeg4_decode_motion(MpegEncContext * s,
869                                  int *mx_ptr, int *my_ptr)
870 {
871     MVTable *mv;
872     int code, mx, my;
873
874     mv = &ff_mv_tables[s->mv_table_index];
875
876     code = get_vlc2(&s->gb, mv->vlc.table, MV_VLC_BITS, 2);
877     if (code < 0){
878         av_log(s->avctx, AV_LOG_ERROR, "illegal MV code at %d %d\n", s->mb_x, s->mb_y);
879         return -1;
880     }
881     if (code == mv->n) {
882         mx = get_bits(&s->gb, 6);
883         my = get_bits(&s->gb, 6);
884     } else {
885         mx = mv->table_mvx[code];
886         my = mv->table_mvy[code];
887     }
888
889     mx += *mx_ptr - 32;
890     my += *my_ptr - 32;
891     /* WARNING : they do not do exactly modulo encoding */
892     if (mx <= -64)
893         mx += 64;
894     else if (mx >= 64)
895         mx -= 64;
896
897     if (my <= -64)
898         my += 64;
899     else if (my >= 64)
900         my -= 64;
901     *mx_ptr = mx;
902     *my_ptr = my;
903     return 0;
904 }
905
906 AVCodec ff_msmpeg4v1_decoder = {
907     .name           = "msmpeg4v1",
908     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
909     .type           = AVMEDIA_TYPE_VIDEO,
910     .id             = AV_CODEC_ID_MSMPEG4V1,
911     .priv_data_size = sizeof(MpegEncContext),
912     .init           = ff_msmpeg4_decode_init,
913     .close          = ff_h263_decode_end,
914     .decode         = ff_h263_decode_frame,
915     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
916     .pix_fmts       = (const enum AVPixelFormat[]) {
917         AV_PIX_FMT_YUV420P,
918         AV_PIX_FMT_NONE
919     },
920 };
921
922 AVCodec ff_msmpeg4v2_decoder = {
923     .name           = "msmpeg4v2",
924     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
925     .type           = AVMEDIA_TYPE_VIDEO,
926     .id             = AV_CODEC_ID_MSMPEG4V2,
927     .priv_data_size = sizeof(MpegEncContext),
928     .init           = ff_msmpeg4_decode_init,
929     .close          = ff_h263_decode_end,
930     .decode         = ff_h263_decode_frame,
931     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
932     .pix_fmts       = (const enum AVPixelFormat[]) {
933         AV_PIX_FMT_YUV420P,
934         AV_PIX_FMT_NONE
935     },
936 };
937
938 AVCodec ff_msmpeg4v3_decoder = {
939     .name           = "msmpeg4",
940     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
941     .type           = AVMEDIA_TYPE_VIDEO,
942     .id             = AV_CODEC_ID_MSMPEG4V3,
943     .priv_data_size = sizeof(MpegEncContext),
944     .init           = ff_msmpeg4_decode_init,
945     .close          = ff_h263_decode_end,
946     .decode         = ff_h263_decode_frame,
947     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
948     .pix_fmts       = (const enum AVPixelFormat[]) {
949         AV_PIX_FMT_YUV420P,
950         AV_PIX_FMT_NONE
951     },
952 };
953
954 AVCodec ff_wmv1_decoder = {
955     .name           = "wmv1",
956     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
957     .type           = AVMEDIA_TYPE_VIDEO,
958     .id             = AV_CODEC_ID_WMV1,
959     .priv_data_size = sizeof(MpegEncContext),
960     .init           = ff_msmpeg4_decode_init,
961     .close          = ff_h263_decode_end,
962     .decode         = ff_h263_decode_frame,
963     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
964     .pix_fmts       = (const enum AVPixelFormat[]) {
965         AV_PIX_FMT_YUV420P,
966         AV_PIX_FMT_NONE
967     },
968 };