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