h263: Always check both dimensions
[libav.git] / libavcodec / ituh263dec.c
1 /*
2 * ITU H263 bitstream decoder
3 * Copyright (c) 2000,2001 Fabrice Bellard
4 * H263+ support.
5 * Copyright (c) 2001 Juan J. Sierralta P
6 * Copyright (c) 2002-2004 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 /**
26 * @file
27 * h263 decoder.
28 */
29
30 #include <limits.h>
31
32 #include "libavutil/attributes.h"
33 #include "libavutil/imgutils.h"
34 #include "libavutil/internal.h"
35 #include "libavutil/mathematics.h"
36 #include "avcodec.h"
37 #include "mpegvideo.h"
38 #include "h263.h"
39 #include "h263data.h"
40 #include "internal.h"
41 #include "mathops.h"
42 #include "mpegutils.h"
43 #include "unary.h"
44 #include "flv.h"
45 #include "rv10.h"
46 #include "mpeg4video.h"
47 #include "mpegvideodata.h"
48
49 // The defines below define the number of bits that are read at once for
50 // reading vlc values. Changing these may improve speed and data cache needs
51 // be aware though that decreasing them may need the number of stages that is
52 // passed to get_vlc* to be increased.
53 #define MV_VLC_BITS 9
54 #define H263_MBTYPE_B_VLC_BITS 6
55 #define CBPC_B_VLC_BITS 3
56
57 static const int h263_mb_type_b_map[15]= {
58 MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
59 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
60 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
61 MB_TYPE_L0 | MB_TYPE_16x16,
62 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_16x16,
63 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
64 MB_TYPE_L1 | MB_TYPE_16x16,
65 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_16x16,
66 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
67 MB_TYPE_L0L1 | MB_TYPE_16x16,
68 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_16x16,
69 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
70 0, //stuffing
71 MB_TYPE_INTRA4x4 | MB_TYPE_CBP,
72 MB_TYPE_INTRA4x4 | MB_TYPE_CBP | MB_TYPE_QUANT,
73 };
74
75 void ff_h263_show_pict_info(MpegEncContext *s){
76 if(s->avctx->debug&FF_DEBUG_PICT_INFO){
77 av_log(s->avctx, AV_LOG_DEBUG, "qp:%d %c size:%d rnd:%d%s%s%s%s%s%s%s%s%s %d/%d\n",
78 s->qscale, av_get_picture_type_char(s->pict_type),
79 s->gb.size_in_bits, 1-s->no_rounding,
80 s->obmc ? " AP" : "",
81 s->umvplus ? " UMV" : "",
82 s->h263_long_vectors ? " LONG" : "",
83 s->h263_plus ? " +" : "",
84 s->h263_aic ? " AIC" : "",
85 s->alt_inter_vlc ? " AIV" : "",
86 s->modified_quant ? " MQ" : "",
87 s->loop_filter ? " LOOP" : "",
88 s->h263_slice_structured ? " SS" : "",
89 s->avctx->framerate.num, s->avctx->framerate.den
90 );
91 }
92 }
93
94 /***********************************************/
95 /* decoding */
96
97 VLC ff_h263_intra_MCBPC_vlc;
98 VLC ff_h263_inter_MCBPC_vlc;
99 VLC ff_h263_cbpy_vlc;
100 static VLC mv_vlc;
101 static VLC h263_mbtype_b_vlc;
102 static VLC cbpc_b_vlc;
103
104 /* init vlcs */
105
106 /* XXX: find a better solution to handle static init */
107 av_cold void ff_h263_decode_init_vlc(void)
108 {
109 static int done = 0;
110
111 if (!done) {
112 done = 1;
113
114 INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
115 ff_h263_intra_MCBPC_bits, 1, 1,
116 ff_h263_intra_MCBPC_code, 1, 1, 72);
117 INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
118 ff_h263_inter_MCBPC_bits, 1, 1,
119 ff_h263_inter_MCBPC_code, 1, 1, 198);
120 INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
121 &ff_h263_cbpy_tab[0][1], 2, 1,
122 &ff_h263_cbpy_tab[0][0], 2, 1, 64);
123 INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
124 &ff_mvtab[0][1], 2, 1,
125 &ff_mvtab[0][0], 2, 1, 538);
126 ff_rl_init(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
127 ff_rl_init(&ff_rl_intra_aic, ff_h263_static_rl_table_store[1]);
128 INIT_VLC_RL(ff_h263_rl_inter, 554);
129 INIT_VLC_RL(ff_rl_intra_aic, 554);
130 INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
131 &ff_h263_mbtype_b_tab[0][1], 2, 1,
132 &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
133 INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
134 &ff_cbpc_b_tab[0][1], 2, 1,
135 &ff_cbpc_b_tab[0][0], 2, 1, 8);
136 }
137 }
138
139 int ff_h263_decode_mba(MpegEncContext *s)
140 {
141 int i, mb_pos;
142
143 for (i = 0; i < 6; i++)
144 if (s->mb_num - 1 <= ff_mba_max[i])
145 break;
146 mb_pos = get_bits(&s->gb, ff_mba_length[i]);
147 s->mb_x = mb_pos % s->mb_width;
148 s->mb_y = mb_pos / s->mb_width;
149
150 return mb_pos;
151 }
152
153 /**
154 * Decode the group of blocks header or slice header.
155 * @return <0 if an error occurred
156 */
157 static int h263_decode_gob_header(MpegEncContext *s)
158 {
159 unsigned int val, gob_number;
160 int left;
161
162 /* Check for GOB Start Code */
163 val = show_bits(&s->gb, 16);
164 if(val)
165 return -1;
166
167 /* We have a GBSC probably with GSTUFF */
168 skip_bits(&s->gb, 16); /* Drop the zeros */
169 left= get_bits_left(&s->gb);
170 //MN: we must check the bits left or we might end in a infinite loop (or segfault)
171 for(;left>13; left--){
172 if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
173 }
174 if(left<=13)
175 return -1;
176
177 if(s->h263_slice_structured){
178 if(get_bits1(&s->gb)==0)
179 return -1;
180
181 ff_h263_decode_mba(s);
182
183 if(s->mb_num > 1583)
184 if(get_bits1(&s->gb)==0)
185 return -1;
186
187 s->qscale = get_bits(&s->gb, 5); /* SQUANT */
188 if(get_bits1(&s->gb)==0)
189 return -1;
190 skip_bits(&s->gb, 2); /* GFID */
191 }else{
192 gob_number = get_bits(&s->gb, 5); /* GN */
193 s->mb_x= 0;
194 s->mb_y= s->gob_index* gob_number;
195 skip_bits(&s->gb, 2); /* GFID */
196 s->qscale = get_bits(&s->gb, 5); /* GQUANT */
197 }
198
199 if(s->mb_y >= s->mb_height)
200 return -1;
201
202 if(s->qscale==0)
203 return -1;
204
205 return 0;
206 }
207
208 /**
209 * Find the next resync_marker.
210 * @param p pointer to buffer to scan
211 * @param end pointer to the end of the buffer
212 * @return pointer to the next resync_marker, or end if none was found
213 */
214 const uint8_t *ff_h263_find_resync_marker(const uint8_t *restrict p, const uint8_t * restrict end)
215 {
216 assert(p < end);
217
218 end-=2;
219 p++;
220 for(;p<end; p+=2){
221 if(!*p){
222 if (!p[-1] && p[1]) return p - 1;
223 else if(!p[ 1] && p[2]) return p;
224 }
225 }
226 return end+2;
227 }
228
229 /**
230 * Decode the group of blocks / video packet header.
231 * @return bit position of the resync_marker, or <0 if none was found
232 */
233 int ff_h263_resync(MpegEncContext *s){
234 int left, pos, ret;
235
236 if(s->codec_id==AV_CODEC_ID_MPEG4){
237 skip_bits1(&s->gb);
238 align_get_bits(&s->gb);
239 }
240
241 if(show_bits(&s->gb, 16)==0){
242 pos= get_bits_count(&s->gb);
243 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
244 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
245 else
246 ret= h263_decode_gob_header(s);
247 if(ret>=0)
248 return pos;
249 }
250 //OK, it's not where it is supposed to be ...
251 s->gb= s->last_resync_gb;
252 align_get_bits(&s->gb);
253 left= get_bits_left(&s->gb);
254
255 for(;left>16+1+5+5; left-=8){
256 if(show_bits(&s->gb, 16)==0){
257 GetBitContext bak= s->gb;
258
259 pos= get_bits_count(&s->gb);
260 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
261 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
262 else
263 ret= h263_decode_gob_header(s);
264 if(ret>=0)
265 return pos;
266
267 s->gb= bak;
268 }
269 skip_bits(&s->gb, 8);
270 }
271
272 return -1;
273 }
274
275 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
276 {
277 int code, val, sign, shift;
278 code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
279
280 if (code == 0)
281 return pred;
282 if (code < 0)
283 return 0xffff;
284
285 sign = get_bits1(&s->gb);
286 shift = f_code - 1;
287 val = code;
288 if (shift) {
289 val = (val - 1) << shift;
290 val |= get_bits(&s->gb, shift);
291 val++;
292 }
293 if (sign)
294 val = -val;
295 val += pred;
296
297 /* modulo decoding */
298 if (!s->h263_long_vectors) {
299 val = sign_extend(val, 5 + f_code);
300 } else {
301 /* horrible h263 long vector mode */
302 if (pred < -31 && val < -63)
303 val += 64;
304 if (pred > 32 && val > 63)
305 val -= 64;
306
307 }
308 return val;
309 }
310
311
312 /* Decode RVLC of H.263+ UMV */
313 static int h263p_decode_umotion(MpegEncContext * s, int pred)
314 {
315 int code = 0, sign;
316
317 if (get_bits1(&s->gb)) /* Motion difference = 0 */
318 return pred;
319
320 code = 2 + get_bits1(&s->gb);
321
322 while (get_bits1(&s->gb))
323 {
324 code <<= 1;
325 code += get_bits1(&s->gb);
326 }
327 sign = code & 1;
328 code >>= 1;
329
330 code = (sign) ? (pred - code) : (pred + code);
331 ff_dlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
332 return code;
333
334 }
335
336 /**
337 * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :)
338 */
339 static void preview_obmc(MpegEncContext *s){
340 GetBitContext gb= s->gb;
341
342 int cbpc, i, pred_x, pred_y, mx, my;
343 int16_t *mot_val;
344 const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
345 const int stride= s->b8_stride*2;
346
347 for(i=0; i<4; i++)
348 s->block_index[i]+= 2;
349 for(i=4; i<6; i++)
350 s->block_index[i]+= 1;
351 s->mb_x++;
352
353 assert(s->pict_type == AV_PICTURE_TYPE_P);
354
355 do{
356 if (get_bits1(&s->gb)) {
357 /* skip mb */
358 mot_val = s->current_picture.motion_val[0][s->block_index[0]];
359 mot_val[0 ]= mot_val[2 ]=
360 mot_val[0+stride]= mot_val[2+stride]= 0;
361 mot_val[1 ]= mot_val[3 ]=
362 mot_val[1+stride]= mot_val[3+stride]= 0;
363
364 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
365 goto end;
366 }
367 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
368 }while(cbpc == 20);
369
370 if(cbpc & 4){
371 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
372 }else{
373 get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
374 if (cbpc & 8) {
375 if(s->modified_quant){
376 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
377 else skip_bits(&s->gb, 5);
378 }else
379 skip_bits(&s->gb, 2);
380 }
381
382 if ((cbpc & 16) == 0) {
383 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
384 /* 16x16 motion prediction */
385 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
386 if (s->umvplus)
387 mx = h263p_decode_umotion(s, pred_x);
388 else
389 mx = ff_h263_decode_motion(s, pred_x, 1);
390
391 if (s->umvplus)
392 my = h263p_decode_umotion(s, pred_y);
393 else
394 my = ff_h263_decode_motion(s, pred_y, 1);
395
396 mot_val[0 ]= mot_val[2 ]=
397 mot_val[0+stride]= mot_val[2+stride]= mx;
398 mot_val[1 ]= mot_val[3 ]=
399 mot_val[1+stride]= mot_val[3+stride]= my;
400 } else {
401 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
402 for(i=0;i<4;i++) {
403 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
404 if (s->umvplus)
405 mx = h263p_decode_umotion(s, pred_x);
406 else
407 mx = ff_h263_decode_motion(s, pred_x, 1);
408
409 if (s->umvplus)
410 my = h263p_decode_umotion(s, pred_y);
411 else
412 my = ff_h263_decode_motion(s, pred_y, 1);
413 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
414 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
415 mot_val[0] = mx;
416 mot_val[1] = my;
417 }
418 }
419 }
420 end:
421
422 for(i=0; i<4; i++)
423 s->block_index[i]-= 2;
424 for(i=4; i<6; i++)
425 s->block_index[i]-= 1;
426 s->mb_x--;
427
428 s->gb= gb;
429 }
430
431 static void h263_decode_dquant(MpegEncContext *s){
432 static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
433
434 if(s->modified_quant){
435 if(get_bits1(&s->gb))
436 s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
437 else
438 s->qscale= get_bits(&s->gb, 5);
439 }else
440 s->qscale += quant_tab[get_bits(&s->gb, 2)];
441 ff_set_qscale(s, s->qscale);
442 }
443
444 static int h263_decode_block(MpegEncContext * s, int16_t * block,
445 int n, int coded)
446 {
447 int code, level, i, j, last, run;
448 RLTable *rl = &ff_h263_rl_inter;
449 const uint8_t *scan_table;
450 GetBitContext gb= s->gb;
451
452 scan_table = s->intra_scantable.permutated;
453 if (s->h263_aic && s->mb_intra) {
454 rl = &ff_rl_intra_aic;
455 i = 0;
456 if (s->ac_pred) {
457 if (s->h263_aic_dir)
458 scan_table = s->intra_v_scantable.permutated; /* left */
459 else
460 scan_table = s->intra_h_scantable.permutated; /* top */
461 }
462 } else if (s->mb_intra) {
463 /* DC coef */
464 if (CONFIG_RV10_DECODER && s->codec_id == AV_CODEC_ID_RV10) {
465 if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
466 int component, diff;
467 component = (n <= 3 ? 0 : n - 4 + 1);
468 level = s->last_dc[component];
469 if (s->rv10_first_dc_coded[component]) {
470 diff = ff_rv_decode_dc(s, n);
471 if (diff == 0xffff)
472 return -1;
473 level += diff;
474 level = level & 0xff; /* handle wrap round */
475 s->last_dc[component] = level;
476 } else {
477 s->rv10_first_dc_coded[component] = 1;
478 }
479 } else {
480 level = get_bits(&s->gb, 8);
481 if (level == 255)
482 level = 128;
483 }
484 }else{
485 level = get_bits(&s->gb, 8);
486 if((level&0x7F) == 0){
487 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
488 if (s->avctx->err_recognition & AV_EF_BITSTREAM)
489 return -1;
490 }
491 if (level == 255)
492 level = 128;
493 }
494 block[0] = level;
495 i = 1;
496 } else {
497 i = 0;
498 }
499 if (!coded) {
500 if (s->mb_intra && s->h263_aic)
501 goto not_coded;
502 s->block_last_index[n] = i - 1;
503 return 0;
504 }
505 retry:
506 for(;;) {
507 code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
508 if (code < 0){
509 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
510 return -1;
511 }
512 if (code == rl->n) {
513 /* escape */
514 if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
515 ff_flv2_decode_ac_esc(&s->gb, &level, &run, &last);
516 } else {
517 last = get_bits1(&s->gb);
518 run = get_bits(&s->gb, 6);
519 level = (int8_t)get_bits(&s->gb, 8);
520 if(level == -128){
521 if (s->codec_id == AV_CODEC_ID_RV10) {
522 /* XXX: should patch encoder too */
523 level = get_sbits(&s->gb, 12);
524 }else{
525 level = get_bits(&s->gb, 5);
526 level |= get_sbits(&s->gb, 6)<<5;
527 }
528 }
529 }
530 } else {
531 run = rl->table_run[code];
532 level = rl->table_level[code];
533 last = code >= rl->last;
534 if (get_bits1(&s->gb))
535 level = -level;
536 }
537 i += run;
538 if (i >= 64){
539 if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
540 //Looks like a hack but no, it's the way it is supposed to work ...
541 rl = &ff_rl_intra_aic;
542 i = 0;
543 s->gb= gb;
544 s->bdsp.clear_block(block);
545 goto retry;
546 }
547 av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
548 return -1;
549 }
550 j = scan_table[i];
551 block[j] = level;
552 if (last)
553 break;
554 i++;
555 }
556 not_coded:
557 if (s->mb_intra && s->h263_aic) {
558 ff_h263_pred_acdc(s, block, n);
559 i = 63;
560 }
561 s->block_last_index[n] = i;
562 return 0;
563 }
564
565 static int h263_skip_b_part(MpegEncContext *s, int cbp)
566 {
567 LOCAL_ALIGNED_16(int16_t, dblock, [64]);
568 int i, mbi;
569
570 /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
571 * but real value should be restored in order to be used later (in OBMC condition)
572 */
573 mbi = s->mb_intra;
574 s->mb_intra = 0;
575 for (i = 0; i < 6; i++) {
576 if (h263_decode_block(s, dblock, i, cbp&32) < 0)
577 return -1;
578 cbp+=cbp;
579 }
580 s->mb_intra = mbi;
581 return 0;
582 }
583
584 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
585 {
586 int c, mv = 1;
587
588 if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
589 c = get_bits1(gb);
590 if (pb_frame == 2 && c)
591 mv = !get_bits1(gb);
592 } else { // h.263 Annex M improved PB-frame
593 mv = get_unary(gb, 0, 4) + 1;
594 c = mv & 1;
595 mv = !!(mv & 2);
596 }
597 if(c)
598 *cbpb = get_bits(gb, 6);
599 return mv;
600 }
601
602 int ff_h263_decode_mb(MpegEncContext *s,
603 int16_t block[6][64])
604 {
605 int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
606 int16_t *mot_val;
607 const int xy= s->mb_x + s->mb_y * s->mb_stride;
608 int cbpb = 0, pb_mv_count = 0;
609
610 assert(!s->h263_pred);
611
612 if (s->pict_type == AV_PICTURE_TYPE_P) {
613 do{
614 if (get_bits1(&s->gb)) {
615 /* skip mb */
616 s->mb_intra = 0;
617 for(i=0;i<6;i++)
618 s->block_last_index[i] = -1;
619 s->mv_dir = MV_DIR_FORWARD;
620 s->mv_type = MV_TYPE_16X16;
621 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
622 s->mv[0][0][0] = 0;
623 s->mv[0][0][1] = 0;
624 s->mb_skipped = !(s->obmc | s->loop_filter);
625 goto end;
626 }
627 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
628 if (cbpc < 0){
629 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
630 return -1;
631 }
632 }while(cbpc == 20);
633
634 s->bdsp.clear_blocks(s->block[0]);
635
636 dquant = cbpc & 8;
637 s->mb_intra = ((cbpc & 4) != 0);
638 if (s->mb_intra) goto intra;
639
640 if(s->pb_frame && get_bits1(&s->gb))
641 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
642 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
643
644 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
645 cbpy ^= 0xF;
646
647 cbp = (cbpc & 3) | (cbpy << 2);
648 if (dquant) {
649 h263_decode_dquant(s);
650 }
651
652 s->mv_dir = MV_DIR_FORWARD;
653 if ((cbpc & 16) == 0) {
654 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
655 /* 16x16 motion prediction */
656 s->mv_type = MV_TYPE_16X16;
657 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
658 if (s->umvplus)
659 mx = h263p_decode_umotion(s, pred_x);
660 else
661 mx = ff_h263_decode_motion(s, pred_x, 1);
662
663 if (mx >= 0xffff)
664 return -1;
665
666 if (s->umvplus)
667 my = h263p_decode_umotion(s, pred_y);
668 else
669 my = ff_h263_decode_motion(s, pred_y, 1);
670
671 if (my >= 0xffff)
672 return -1;
673 s->mv[0][0][0] = mx;
674 s->mv[0][0][1] = my;
675
676 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
677 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
678 } else {
679 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
680 s->mv_type = MV_TYPE_8X8;
681 for(i=0;i<4;i++) {
682 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
683 if (s->umvplus)
684 mx = h263p_decode_umotion(s, pred_x);
685 else
686 mx = ff_h263_decode_motion(s, pred_x, 1);
687 if (mx >= 0xffff)
688 return -1;
689
690 if (s->umvplus)
691 my = h263p_decode_umotion(s, pred_y);
692 else
693 my = ff_h263_decode_motion(s, pred_y, 1);
694 if (my >= 0xffff)
695 return -1;
696 s->mv[0][i][0] = mx;
697 s->mv[0][i][1] = my;
698 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
699 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
700 mot_val[0] = mx;
701 mot_val[1] = my;
702 }
703 }
704 } else if(s->pict_type==AV_PICTURE_TYPE_B) {
705 int mb_type;
706 const int stride= s->b8_stride;
707 int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
708 int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
709 // const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
710
711 //FIXME ugly
712 mot_val0[0 ]= mot_val0[2 ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
713 mot_val0[1 ]= mot_val0[3 ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
714 mot_val1[0 ]= mot_val1[2 ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
715 mot_val1[1 ]= mot_val1[3 ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
716
717 do{
718 mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
719 if (mb_type < 0){
720 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
721 return -1;
722 }
723
724 mb_type= h263_mb_type_b_map[ mb_type ];
725 }while(!mb_type);
726
727 s->mb_intra = IS_INTRA(mb_type);
728 if(HAS_CBP(mb_type)){
729 s->bdsp.clear_blocks(s->block[0]);
730 cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
731 if(s->mb_intra){
732 dquant = IS_QUANT(mb_type);
733 goto intra;
734 }
735
736 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
737
738 if (cbpy < 0){
739 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
740 return -1;
741 }
742
743 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
744 cbpy ^= 0xF;
745
746 cbp = (cbpc & 3) | (cbpy << 2);
747 }else
748 cbp=0;
749
750 assert(!s->mb_intra);
751
752 if(IS_QUANT(mb_type)){
753 h263_decode_dquant(s);
754 }
755
756 if(IS_DIRECT(mb_type)){
757 if (!s->pp_time)
758 return AVERROR_INVALIDDATA;
759 s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
760 mb_type |= ff_mpeg4_set_direct_mv(s, 0, 0);
761 }else{
762 s->mv_dir = 0;
763 s->mv_type= MV_TYPE_16X16;
764 //FIXME UMV
765
766 if(USES_LIST(mb_type, 0)){
767 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &mx, &my);
768 s->mv_dir = MV_DIR_FORWARD;
769
770 mx = ff_h263_decode_motion(s, mx, 1);
771 my = ff_h263_decode_motion(s, my, 1);
772
773 s->mv[0][0][0] = mx;
774 s->mv[0][0][1] = my;
775 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
776 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
777 }
778
779 if(USES_LIST(mb_type, 1)){
780 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &mx, &my);
781 s->mv_dir |= MV_DIR_BACKWARD;
782
783 mx = ff_h263_decode_motion(s, mx, 1);
784 my = ff_h263_decode_motion(s, my, 1);
785
786 s->mv[1][0][0] = mx;
787 s->mv[1][0][1] = my;
788 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
789 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
790 }
791 }
792
793 s->current_picture.mb_type[xy] = mb_type;
794 } else { /* I-Frame */
795 do{
796 cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
797 if (cbpc < 0){
798 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
799 return -1;
800 }
801 }while(cbpc == 8);
802
803 s->bdsp.clear_blocks(s->block[0]);
804
805 dquant = cbpc & 4;
806 s->mb_intra = 1;
807 intra:
808 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
809 if (s->h263_aic) {
810 s->ac_pred = get_bits1(&s->gb);
811 if(s->ac_pred){
812 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
813
814 s->h263_aic_dir = get_bits1(&s->gb);
815 }
816 }else
817 s->ac_pred = 0;
818
819 if(s->pb_frame && get_bits1(&s->gb))
820 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
821 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
822 if(cbpy<0){
823 av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
824 return -1;
825 }
826 cbp = (cbpc & 3) | (cbpy << 2);
827 if (dquant) {
828 h263_decode_dquant(s);
829 }
830
831 pb_mv_count += !!s->pb_frame;
832 }
833
834 while(pb_mv_count--){
835 ff_h263_decode_motion(s, 0, 1);
836 ff_h263_decode_motion(s, 0, 1);
837 }
838
839 /* decode each block */
840 for (i = 0; i < 6; i++) {
841 if (h263_decode_block(s, block[i], i, cbp&32) < 0)
842 return -1;
843 cbp+=cbp;
844 }
845
846 if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
847 return -1;
848 if(s->obmc && !s->mb_intra){
849 if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
850 preview_obmc(s);
851 }
852 end:
853
854 /* per-MB end of slice check */
855 {
856 int v= show_bits(&s->gb, 16);
857
858 if (get_bits_left(&s->gb) < 16) {
859 v >>= 16 - get_bits_left(&s->gb);
860 }
861
862 if(v==0)
863 return SLICE_END;
864 }
865
866 return SLICE_OK;
867 }
868
869 /* most is hardcoded. should extend to handle all h263 streams */
870 int ff_h263_decode_picture_header(MpegEncContext *s)
871 {
872 int format, width, height, i, ret;
873 uint32_t startcode;
874
875 align_get_bits(&s->gb);
876
877 startcode= get_bits(&s->gb, 22-8);
878
879 for(i= get_bits_left(&s->gb); i>24; i-=8) {
880 startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
881
882 if(startcode == 0x20)
883 break;
884 }
885
886 if (startcode != 0x20) {
887 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
888 return -1;
889 }
890 /* temporal reference */
891 i = get_bits(&s->gb, 8); /* picture timestamp */
892 if( (s->picture_number&~0xFF)+i < s->picture_number)
893 i+= 256;
894 s->picture_number= (s->picture_number&~0xFF) + i;
895
896 /* PTYPE starts here */
897 if (get_bits1(&s->gb) != 1) {
898 /* marker */
899 av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n");
900 return -1;
901 }
902 if (get_bits1(&s->gb) != 0) {
903 av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
904 return -1; /* h263 id */
905 }
906 skip_bits1(&s->gb); /* split screen off */
907 skip_bits1(&s->gb); /* camera off */
908 skip_bits1(&s->gb); /* freeze picture release off */
909
910 format = get_bits(&s->gb, 3);
911 /*
912 0 forbidden
913 1 sub-QCIF
914 10 QCIF
915 7 extended PTYPE (PLUSPTYPE)
916 */
917
918 if (format != 7 && format != 6) {
919 s->h263_plus = 0;
920 /* H.263v1 */
921 width = ff_h263_format[format][0];
922 height = ff_h263_format[format][1];
923
924 s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
925
926 s->h263_long_vectors = get_bits1(&s->gb);
927
928 if (get_bits1(&s->gb) != 0) {
929 av_log(s->avctx, AV_LOG_ERROR, "H263 SAC not supported\n");
930 return -1; /* SAC: off */
931 }
932 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
933 s->unrestricted_mv = s->h263_long_vectors || s->obmc;
934
935 s->pb_frame = get_bits1(&s->gb);
936 s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
937 skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
938
939 s->width = width;
940 s->height = height;
941 s->avctx->sample_aspect_ratio= (AVRational){12,11};
942 s->avctx->framerate = (AVRational){ 30000, 1001 };
943 } else {
944 int ufep;
945
946 /* H.263v2 */
947 s->h263_plus = 1;
948 ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
949
950 /* ufep other than 0 and 1 are reserved */
951 if (ufep == 1) {
952 /* OPPTYPE */
953 format = get_bits(&s->gb, 3);
954 ff_dlog(s->avctx, "ufep=1, format: %d\n", format);
955 s->custom_pcf= get_bits1(&s->gb);
956 s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
957 if (get_bits1(&s->gb) != 0) {
958 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
959 }
960 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
961 s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
962 s->loop_filter= get_bits1(&s->gb);
963 s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter;
964
965 s->h263_slice_structured= get_bits1(&s->gb);
966 if (get_bits1(&s->gb) != 0) {
967 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
968 }
969 if (get_bits1(&s->gb) != 0) {
970 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
971 }
972 s->alt_inter_vlc= get_bits1(&s->gb);
973 s->modified_quant= get_bits1(&s->gb);
974 if(s->modified_quant)
975 s->chroma_qscale_table= ff_h263_chroma_qscale_table;
976
977 skip_bits(&s->gb, 1); /* Prevent start code emulation */
978
979 skip_bits(&s->gb, 3); /* Reserved */
980 } else if (ufep != 0) {
981 av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
982 return -1;
983 }
984
985 /* MPPTYPE */
986 s->pict_type = get_bits(&s->gb, 3);
987 switch(s->pict_type){
988 case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
989 case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
990 case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
991 case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
992 case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
993 default:
994 return -1;
995 }
996 skip_bits(&s->gb, 2);
997 s->no_rounding = get_bits1(&s->gb);
998 skip_bits(&s->gb, 4);
999
1000 /* Get the picture dimensions */
1001 if (ufep) {
1002 if (format == 6) {
1003 /* Custom Picture Format (CPFMT) */
1004 s->aspect_ratio_info = get_bits(&s->gb, 4);
1005 ff_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
1006 /* aspect ratios:
1007 0 - forbidden
1008 1 - 1:1
1009 2 - 12:11 (CIF 4:3)
1010 3 - 10:11 (525-type 4:3)
1011 4 - 16:11 (CIF 16:9)
1012 5 - 40:33 (525-type 16:9)
1013 6-14 - reserved
1014 */
1015 width = (get_bits(&s->gb, 9) + 1) * 4;
1016 skip_bits1(&s->gb);
1017 height = get_bits(&s->gb, 9) * 4;
1018 ff_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1019 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1020 /* aspected dimensions */
1021 s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1022 s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1023 }else{
1024 s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1025 }
1026 } else {
1027 width = ff_h263_format[format][0];
1028 height = ff_h263_format[format][1];
1029 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1030 }
1031 if ((width == 0) || (height == 0))
1032 return -1;
1033 s->width = width;
1034 s->height = height;
1035
1036 if(s->custom_pcf){
1037 int gcd;
1038 s->avctx->framerate.num = 1800000;
1039 s->avctx->framerate.den = 1000 + get_bits1(&s->gb);
1040 s->avctx->framerate.den *= get_bits(&s->gb, 7);
1041 if(s->avctx->framerate.den == 0){
1042 av_log(s, AV_LOG_ERROR, "zero framerate\n");
1043 return -1;
1044 }
1045 gcd= av_gcd(s->avctx->framerate.den, s->avctx->framerate.num);
1046 s->avctx->framerate.den /= gcd;
1047 s->avctx->framerate.num /= gcd;
1048 }else{
1049 s->avctx->framerate = (AVRational){ 30000, 1001 };
1050 }
1051 }
1052
1053 if(s->custom_pcf){
1054 skip_bits(&s->gb, 2); //extended Temporal reference
1055 }
1056
1057 if (ufep) {
1058 if (s->umvplus) {
1059 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
1060 skip_bits1(&s->gb);
1061 }
1062 if(s->h263_slice_structured){
1063 if (get_bits1(&s->gb) != 0) {
1064 av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
1065 }
1066 if (get_bits1(&s->gb) != 0) {
1067 av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1068 }
1069 }
1070 }
1071
1072 s->qscale = get_bits(&s->gb, 5);
1073 }
1074
1075 if ((ret = av_image_check_size(s->width, s->height, 0, s)) < 0)
1076 return ret;
1077
1078 s->mb_width = (s->width + 15) / 16;
1079 s->mb_height = (s->height + 15) / 16;
1080 s->mb_num = s->mb_width * s->mb_height;
1081
1082 if (s->pb_frame) {
1083 skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1084 if (s->custom_pcf)
1085 skip_bits(&s->gb, 2); //extended Temporal reference
1086 skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1087 }
1088
1089 if (s->pict_type!=AV_PICTURE_TYPE_B) {
1090 s->time = s->picture_number;
1091 s->pp_time = s->time - s->last_non_b_time;
1092 s->last_non_b_time = s->time;
1093 }else{
1094 s->time = s->picture_number;
1095 s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
1096 if (s->pp_time <=s->pb_time ||
1097 s->pp_time <= s->pp_time - s->pb_time ||
1098 s->pp_time <= 0){
1099 s->pp_time = 2;
1100 s->pb_time = 1;
1101 }
1102 ff_mpeg4_init_direct_mv(s);
1103 }
1104
1105 /* PEI */
1106 while (get_bits1(&s->gb) != 0) {
1107 skip_bits(&s->gb, 8);
1108 }
1109
1110 if(s->h263_slice_structured){
1111 if (get_bits1(&s->gb) != 1) {
1112 av_log(s->avctx, AV_LOG_ERROR, "SEPB1 marker missing\n");
1113 return -1;
1114 }
1115
1116 ff_h263_decode_mba(s);
1117
1118 if (get_bits1(&s->gb) != 1) {
1119 av_log(s->avctx, AV_LOG_ERROR, "SEPB2 marker missing\n");
1120 return -1;
1121 }
1122 }
1123 s->f_code = 1;
1124
1125 if(s->h263_aic){
1126 s->y_dc_scale_table=
1127 s->c_dc_scale_table= ff_aic_dc_scale_table;
1128 }else{
1129 s->y_dc_scale_table=
1130 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1131 }
1132
1133 ff_h263_show_pict_info(s);
1134 if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO")){
1135 int i,j;
1136 for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1137 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1138 for(i=0; i<13; i++){
1139 for(j=0; j<3; j++){
1140 int v= get_bits(&s->gb, 8);
1141 v |= get_sbits(&s->gb, 8)<<8;
1142 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1143 }
1144 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1145 }
1146 for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1147 }
1148
1149 return 0;
1150 }