libavformat: Add an ff_ prefix to some lavf internal symbols
[libav.git] / libavcodec / ituh263dec.c
CommitLineData
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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 *
2912e87a 8 * This file is part of Libav.
fc53b6af 9 *
2912e87a 10 * Libav is free software; you can redistribute it and/or
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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 *
2912e87a 15 * Libav is distributed in the hope that it will be useful,
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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
2912e87a 21 * License along with Libav; if not, write to the Free Software
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22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25/**
ba87f080 26 * @file
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27 * h263 decoder.
28 */
29
30//#define DEBUG
31#include <limits.h>
32
0ebcdf5c 33#include "libavutil/mathematics.h"
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34#include "dsputil.h"
35#include "avcodec.h"
36#include "mpegvideo.h"
37#include "h263.h"
38#include "mathops.h"
39#include "unary.h"
40#include "flv.h"
41#include "mpeg4video.h"
42
43//#undef NDEBUG
44//#include <assert.h>
45
46// The defines below define the number of bits that are read at once for
47// reading vlc values. Changing these may improve speed and data cache needs
48// be aware though that decreasing them may need the number of stages that is
49// passed to get_vlc* to be increased.
50#define MV_VLC_BITS 9
51#define H263_MBTYPE_B_VLC_BITS 6
52#define CBPC_B_VLC_BITS 3
53
54static const int h263_mb_type_b_map[15]= {
55 MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
56 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
57 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
58 MB_TYPE_L0 | MB_TYPE_16x16,
59 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_16x16,
60 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
61 MB_TYPE_L1 | MB_TYPE_16x16,
62 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_16x16,
63 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
64 MB_TYPE_L0L1 | MB_TYPE_16x16,
65 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_16x16,
66 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
67 0, //stuffing
68 MB_TYPE_INTRA4x4 | MB_TYPE_CBP,
69 MB_TYPE_INTRA4x4 | MB_TYPE_CBP | MB_TYPE_QUANT,
70};
71
72void ff_h263_show_pict_info(MpegEncContext *s){
73 if(s->avctx->debug&FF_DEBUG_PICT_INFO){
74 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",
6209669d 75 s->qscale, av_get_picture_type_char(s->pict_type),
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76 s->gb.size_in_bits, 1-s->no_rounding,
77 s->obmc ? " AP" : "",
78 s->umvplus ? " UMV" : "",
79 s->h263_long_vectors ? " LONG" : "",
80 s->h263_plus ? " +" : "",
81 s->h263_aic ? " AIC" : "",
82 s->alt_inter_vlc ? " AIV" : "",
83 s->modified_quant ? " MQ" : "",
84 s->loop_filter ? " LOOP" : "",
85 s->h263_slice_structured ? " SS" : "",
86 s->avctx->time_base.den, s->avctx->time_base.num
87 );
88 }
89}
90
91/***********************************************/
92/* decoding */
93
94VLC ff_h263_intra_MCBPC_vlc;
95VLC ff_h263_inter_MCBPC_vlc;
96VLC ff_h263_cbpy_vlc;
97static VLC mv_vlc;
98static VLC h263_mbtype_b_vlc;
99static VLC cbpc_b_vlc;
100
101/* init vlcs */
102
103/* XXX: find a better solution to handle static init */
104void h263_decode_init_vlc(MpegEncContext *s)
105{
106 static int done = 0;
107
108 if (!done) {
109 done = 1;
110
111 INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
112 ff_h263_intra_MCBPC_bits, 1, 1,
113 ff_h263_intra_MCBPC_code, 1, 1, 72);
114 INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
115 ff_h263_inter_MCBPC_bits, 1, 1,
116 ff_h263_inter_MCBPC_code, 1, 1, 198);
117 INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
118 &ff_h263_cbpy_tab[0][1], 2, 1,
119 &ff_h263_cbpy_tab[0][0], 2, 1, 64);
120 INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
121 &mvtab[0][1], 2, 1,
122 &mvtab[0][0], 2, 1, 538);
123 init_rl(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
124 init_rl(&rl_intra_aic, ff_h263_static_rl_table_store[1]);
125 INIT_VLC_RL(ff_h263_rl_inter, 554);
126 INIT_VLC_RL(rl_intra_aic, 554);
127 INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
128 &h263_mbtype_b_tab[0][1], 2, 1,
129 &h263_mbtype_b_tab[0][0], 2, 1, 80);
130 INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
131 &cbpc_b_tab[0][1], 2, 1,
132 &cbpc_b_tab[0][0], 2, 1, 8);
133 }
134}
135
136int ff_h263_decode_mba(MpegEncContext *s)
137{
138 int i, mb_pos;
139
140 for(i=0; i<6; i++){
141 if(s->mb_num-1 <= ff_mba_max[i]) break;
142 }
143 mb_pos= get_bits(&s->gb, ff_mba_length[i]);
144 s->mb_x= mb_pos % s->mb_width;
145 s->mb_y= mb_pos / s->mb_width;
146
147 return mb_pos;
148}
149
150/**
58c42af7 151 * Decode the group of blocks header or slice header.
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152 * @return <0 if an error occurred
153 */
154static int h263_decode_gob_header(MpegEncContext *s)
155{
e65ab9d9 156 unsigned int val, gob_number;
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157 int left;
158
159 /* Check for GOB Start Code */
160 val = show_bits(&s->gb, 16);
161 if(val)
162 return -1;
163
164 /* We have a GBSC probably with GSTUFF */
165 skip_bits(&s->gb, 16); /* Drop the zeros */
166 left= get_bits_left(&s->gb);
167 //MN: we must check the bits left or we might end in a infinite loop (or segfault)
168 for(;left>13; left--){
169 if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
170 }
171 if(left<=13)
172 return -1;
173
174 if(s->h263_slice_structured){
175 if(get_bits1(&s->gb)==0)
176 return -1;
177
178 ff_h263_decode_mba(s);
179
180 if(s->mb_num > 1583)
181 if(get_bits1(&s->gb)==0)
182 return -1;
183
184 s->qscale = get_bits(&s->gb, 5); /* SQUANT */
185 if(get_bits1(&s->gb)==0)
186 return -1;
e65ab9d9 187 skip_bits(&s->gb, 2); /* GFID */
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188 }else{
189 gob_number = get_bits(&s->gb, 5); /* GN */
190 s->mb_x= 0;
191 s->mb_y= s->gob_index* gob_number;
e65ab9d9 192 skip_bits(&s->gb, 2); /* GFID */
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193 s->qscale = get_bits(&s->gb, 5); /* GQUANT */
194 }
195
196 if(s->mb_y >= s->mb_height)
197 return -1;
198
199 if(s->qscale==0)
200 return -1;
201
202 return 0;
203}
204
205/**
58c42af7 206 * Find the next resync_marker.
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207 * @param p pointer to buffer to scan
208 * @param end pointer to the end of the buffer
209 * @return pointer to the next resync_marker, or end if none was found
210 */
211const uint8_t *ff_h263_find_resync_marker(const uint8_t *restrict p, const uint8_t * restrict end)
212{
213 assert(p < end);
214
215 end-=2;
216 p++;
217 for(;p<end; p+=2){
218 if(!*p){
219 if (!p[-1] && p[1]) return p - 1;
220 else if(!p[ 1] && p[2]) return p;
221 }
222 }
223 return end+2;
224}
225
226/**
58c42af7 227 * Decode the group of blocks / video packet header.
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228 * @return bit position of the resync_marker, or <0 if none was found
229 */
230int ff_h263_resync(MpegEncContext *s){
231 int left, pos, ret;
232
233 if(s->codec_id==CODEC_ID_MPEG4){
234 skip_bits1(&s->gb);
235 align_get_bits(&s->gb);
236 }
237
238 if(show_bits(&s->gb, 16)==0){
239 pos= get_bits_count(&s->gb);
240 if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4)
241 ret= mpeg4_decode_video_packet_header(s);
242 else
243 ret= h263_decode_gob_header(s);
244 if(ret>=0)
245 return pos;
246 }
247 //OK, it's not where it is supposed to be ...
248 s->gb= s->last_resync_gb;
249 align_get_bits(&s->gb);
250 left= get_bits_left(&s->gb);
251
252 for(;left>16+1+5+5; left-=8){
253 if(show_bits(&s->gb, 16)==0){
254 GetBitContext bak= s->gb;
255
256 pos= get_bits_count(&s->gb);
257 if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4)
258 ret= mpeg4_decode_video_packet_header(s);
259 else
260 ret= h263_decode_gob_header(s);
261 if(ret>=0)
262 return pos;
263
264 s->gb= bak;
265 }
266 skip_bits(&s->gb, 8);
267 }
268
269 return -1;
270}
271
272int h263_decode_motion(MpegEncContext * s, int pred, int f_code)
273{
aa498fef 274 int code, val, sign, shift;
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275 code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
276
277 if (code == 0)
278 return pred;
279 if (code < 0)
280 return 0xffff;
281
282 sign = get_bits1(&s->gb);
283 shift = f_code - 1;
284 val = code;
285 if (shift) {
286 val = (val - 1) << shift;
287 val |= get_bits(&s->gb, shift);
288 val++;
289 }
290 if (sign)
291 val = -val;
292 val += pred;
293
294 /* modulo decoding */
295 if (!s->h263_long_vectors) {
aa498fef 296 val = sign_extend(val, 5 + f_code);
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297 } else {
298 /* horrible h263 long vector mode */
299 if (pred < -31 && val < -63)
300 val += 64;
301 if (pred > 32 && val > 63)
302 val -= 64;
303
304 }
305 return val;
306}
307
308
58c42af7 309/* Decode RVLC of H.263+ UMV */
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310static int h263p_decode_umotion(MpegEncContext * s, int pred)
311{
312 int code = 0, sign;
313
314 if (get_bits1(&s->gb)) /* Motion difference = 0 */
315 return pred;
316
317 code = 2 + get_bits1(&s->gb);
318
319 while (get_bits1(&s->gb))
320 {
321 code <<= 1;
322 code += get_bits1(&s->gb);
323 }
324 sign = code & 1;
325 code >>= 1;
326
327 code = (sign) ? (pred - code) : (pred + code);
dfd2a005 328 av_dlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
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329 return code;
330
331}
332
333/**
334 * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :)
335 */
336static void preview_obmc(MpegEncContext *s){
337 GetBitContext gb= s->gb;
338
339 int cbpc, i, pred_x, pred_y, mx, my;
340 int16_t *mot_val;
341 const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
342 const int stride= s->b8_stride*2;
343
344 for(i=0; i<4; i++)
345 s->block_index[i]+= 2;
346 for(i=4; i<6; i++)
347 s->block_index[i]+= 1;
348 s->mb_x++;
349
975a1447 350 assert(s->pict_type == AV_PICTURE_TYPE_P);
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351
352 do{
353 if (get_bits1(&s->gb)) {
354 /* skip mb */
657ccb5a 355 mot_val = s->current_picture.f.motion_val[0][s->block_index[0]];
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356 mot_val[0 ]= mot_val[2 ]=
357 mot_val[0+stride]= mot_val[2+stride]= 0;
358 mot_val[1 ]= mot_val[3 ]=
359 mot_val[1+stride]= mot_val[3+stride]= 0;
360
657ccb5a 361 s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
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362 goto end;
363 }
364 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
365 }while(cbpc == 20);
366
367 if(cbpc & 4){
657ccb5a 368 s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
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369 }else{
370 get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
371 if (cbpc & 8) {
372 if(s->modified_quant){
373 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
374 else skip_bits(&s->gb, 5);
375 }else
376 skip_bits(&s->gb, 2);
377 }
378
379 if ((cbpc & 16) == 0) {
657ccb5a 380 s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
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381 /* 16x16 motion prediction */
382 mot_val= h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
383 if (s->umvplus)
384 mx = h263p_decode_umotion(s, pred_x);
385 else
386 mx = h263_decode_motion(s, pred_x, 1);
387
388 if (s->umvplus)
389 my = h263p_decode_umotion(s, pred_y);
390 else
391 my = h263_decode_motion(s, pred_y, 1);
392
393 mot_val[0 ]= mot_val[2 ]=
394 mot_val[0+stride]= mot_val[2+stride]= mx;
395 mot_val[1 ]= mot_val[3 ]=
396 mot_val[1+stride]= mot_val[3+stride]= my;
397 } else {
657ccb5a 398 s->current_picture.f.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
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399 for(i=0;i<4;i++) {
400 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y);
401 if (s->umvplus)
402 mx = h263p_decode_umotion(s, pred_x);
403 else
404 mx = h263_decode_motion(s, pred_x, 1);
405
406 if (s->umvplus)
407 my = h263p_decode_umotion(s, pred_y);
408 else
409 my = h263_decode_motion(s, pred_y, 1);
410 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
411 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
412 mot_val[0] = mx;
413 mot_val[1] = my;
414 }
415 }
416 }
417end:
418
419 for(i=0; i<4; i++)
420 s->block_index[i]-= 2;
421 for(i=4; i<6; i++)
422 s->block_index[i]-= 1;
423 s->mb_x--;
424
425 s->gb= gb;
426}
427
428static void h263_decode_dquant(MpegEncContext *s){
429 static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
430
431 if(s->modified_quant){
432 if(get_bits1(&s->gb))
433 s->qscale= modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
434 else
435 s->qscale= get_bits(&s->gb, 5);
436 }else
437 s->qscale += quant_tab[get_bits(&s->gb, 2)];
438 ff_set_qscale(s, s->qscale);
439}
440
441static int h263_decode_block(MpegEncContext * s, DCTELEM * block,
442 int n, int coded)
443{
444 int code, level, i, j, last, run;
445 RLTable *rl = &ff_h263_rl_inter;
446 const uint8_t *scan_table;
447 GetBitContext gb= s->gb;
448
449 scan_table = s->intra_scantable.permutated;
450 if (s->h263_aic && s->mb_intra) {
451 rl = &rl_intra_aic;
452 i = 0;
453 if (s->ac_pred) {
454 if (s->h263_aic_dir)
455 scan_table = s->intra_v_scantable.permutated; /* left */
456 else
457 scan_table = s->intra_h_scantable.permutated; /* top */
458 }
459 } else if (s->mb_intra) {
460 /* DC coef */
461 if(s->codec_id == CODEC_ID_RV10){
462#if CONFIG_RV10_DECODER
975a1447 463 if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
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464 int component, diff;
465 component = (n <= 3 ? 0 : n - 4 + 1);
466 level = s->last_dc[component];
467 if (s->rv10_first_dc_coded[component]) {
468 diff = rv_decode_dc(s, n);
469 if (diff == 0xffff)
470 return -1;
471 level += diff;
472 level = level & 0xff; /* handle wrap round */
473 s->last_dc[component] = level;
474 } else {
475 s->rv10_first_dc_coded[component] = 1;
476 }
477 } else {
478 level = get_bits(&s->gb, 8);
479 if (level == 255)
480 level = 128;
481 }
482#endif
483 }else{
484 level = get_bits(&s->gb, 8);
485 if((level&0x7F) == 0){
486 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
5b22d6e1 487 if(s->err_recognition & AV_EF_BITSTREAM)
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488 return -1;
489 }
490 if (level == 255)
491 level = 128;
492 }
493 block[0] = level;
494 i = 1;
495 } else {
496 i = 0;
497 }
498 if (!coded) {
499 if (s->mb_intra && s->h263_aic)
500 goto not_coded;
501 s->block_last_index[n] = i - 1;
502 return 0;
503 }
504retry:
505 for(;;) {
506 code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
507 if (code < 0){
508 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
509 return -1;
510 }
511 if (code == rl->n) {
512 /* escape */
513 if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
514 ff_flv2_decode_ac_esc(&s->gb, &level, &run, &last);
515 } else {
516 last = get_bits1(&s->gb);
517 run = get_bits(&s->gb, 6);
518 level = (int8_t)get_bits(&s->gb, 8);
519 if(level == -128){
520 if (s->codec_id == CODEC_ID_RV10) {
521 /* XXX: should patch encoder too */
522 level = get_sbits(&s->gb, 12);
523 }else{
524 level = get_bits(&s->gb, 5);
525 level |= get_sbits(&s->gb, 6)<<5;
526 }
527 }
528 }
529 } else {
530 run = rl->table_run[code];
531 level = rl->table_level[code];
532 last = code >= rl->last;
533 if (get_bits1(&s->gb))
534 level = -level;
535 }
536 i += run;
537 if (i >= 64){
538 if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
539 //Looks like a hack but no, it's the way it is supposed to work ...
540 rl = &rl_intra_aic;
541 i = 0;
542 s->gb= gb;
543 s->dsp.clear_block(block);
544 goto retry;
545 }
546 av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
547 return -1;
548 }
549 j = scan_table[i];
550 block[j] = level;
551 if (last)
552 break;
553 i++;
554 }
555not_coded:
556 if (s->mb_intra && s->h263_aic) {
557 h263_pred_acdc(s, block, n);
558 i = 63;
559 }
560 s->block_last_index[n] = i;
561 return 0;
562}
563
564static int h263_skip_b_part(MpegEncContext *s, int cbp)
565{
40d11227 566 LOCAL_ALIGNED_16(DCTELEM, dblock, [64]);
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567 int i, mbi;
568
569 /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
570 * but real value should be restored in order to be used later (in OBMC condition)
571 */
572 mbi = s->mb_intra;
573 s->mb_intra = 0;
574 for (i = 0; i < 6; i++) {
575 if (h263_decode_block(s, dblock, i, cbp&32) < 0)
576 return -1;
577 cbp+=cbp;
578 }
579 s->mb_intra = mbi;
580 return 0;
581}
582
583static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
584{
585 int c, mv = 1;
586
587 if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
588 c = get_bits1(gb);
589 if (pb_frame == 2 && c)
590 mv = !get_bits1(gb);
591 } else { // h.263 Annex M improved PB-frame
592 mv = get_unary(gb, 0, 4) + 1;
593 c = mv & 1;
594 mv = !!(mv & 2);
595 }
596 if(c)
597 *cbpb = get_bits(gb, 6);
598 return mv;
599}
600
601int ff_h263_decode_mb(MpegEncContext *s,
602 DCTELEM block[6][64])
603{
604 int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
605 int16_t *mot_val;
606 const int xy= s->mb_x + s->mb_y * s->mb_stride;
607 int cbpb = 0, pb_mv_count = 0;
608
609 assert(!s->h263_pred);
610
975a1447 611 if (s->pict_type == AV_PICTURE_TYPE_P) {
fc53b6af
MN
612 do{
613 if (get_bits1(&s->gb)) {
614 /* skip mb */
615 s->mb_intra = 0;
616 for(i=0;i<6;i++)
617 s->block_last_index[i] = -1;
618 s->mv_dir = MV_DIR_FORWARD;
619 s->mv_type = MV_TYPE_16X16;
657ccb5a 620 s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
fc53b6af
MN
621 s->mv[0][0][0] = 0;
622 s->mv[0][0][1] = 0;
623 s->mb_skipped = !(s->obmc | s->loop_filter);
624 goto end;
625 }
626 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
627 if (cbpc < 0){
628 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
629 return -1;
630 }
631 }while(cbpc == 20);
632
633 s->dsp.clear_blocks(s->block[0]);
634
635 dquant = cbpc & 8;
636 s->mb_intra = ((cbpc & 4) != 0);
637 if (s->mb_intra) goto intra;
638
639 if(s->pb_frame && get_bits1(&s->gb))
640 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
641 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
642
643 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
644 cbpy ^= 0xF;
645
646 cbp = (cbpc & 3) | (cbpy << 2);
647 if (dquant) {
648 h263_decode_dquant(s);
649 }
650
651 s->mv_dir = MV_DIR_FORWARD;
652 if ((cbpc & 16) == 0) {
657ccb5a 653 s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
fc53b6af
MN
654 /* 16x16 motion prediction */
655 s->mv_type = MV_TYPE_16X16;
656 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
657 if (s->umvplus)
658 mx = h263p_decode_umotion(s, pred_x);
659 else
660 mx = h263_decode_motion(s, pred_x, 1);
661
662 if (mx >= 0xffff)
663 return -1;
664
665 if (s->umvplus)
666 my = h263p_decode_umotion(s, pred_y);
667 else
668 my = h263_decode_motion(s, pred_y, 1);
669
670 if (my >= 0xffff)
671 return -1;
672 s->mv[0][0][0] = mx;
673 s->mv[0][0][1] = my;
674
675 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
676 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
677 } else {
657ccb5a 678 s->current_picture.f.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
fc53b6af
MN
679 s->mv_type = MV_TYPE_8X8;
680 for(i=0;i<4;i++) {
681 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y);
682 if (s->umvplus)
683 mx = h263p_decode_umotion(s, pred_x);
684 else
685 mx = h263_decode_motion(s, pred_x, 1);
686 if (mx >= 0xffff)
687 return -1;
688
689 if (s->umvplus)
690 my = h263p_decode_umotion(s, pred_y);
691 else
692 my = h263_decode_motion(s, pred_y, 1);
693 if (my >= 0xffff)
694 return -1;
695 s->mv[0][i][0] = mx;
696 s->mv[0][i][1] = my;
697 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
698 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
699 mot_val[0] = mx;
700 mot_val[1] = my;
701 }
702 }
975a1447 703 } else if(s->pict_type==AV_PICTURE_TYPE_B) {
fc53b6af
MN
704 int mb_type;
705 const int stride= s->b8_stride;
657ccb5a
DB
706 int16_t *mot_val0 = s->current_picture.f.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
707 int16_t *mot_val1 = s->current_picture.f.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
fc53b6af
MN
708// const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
709
710 //FIXME ugly
711 mot_val0[0 ]= mot_val0[2 ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
712 mot_val0[1 ]= mot_val0[3 ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
713 mot_val1[0 ]= mot_val1[2 ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
714 mot_val1[1 ]= mot_val1[3 ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
715
716 do{
717 mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
718 if (mb_type < 0){
719 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
720 return -1;
721 }
722
723 mb_type= h263_mb_type_b_map[ mb_type ];
724 }while(!mb_type);
725
726 s->mb_intra = IS_INTRA(mb_type);
727 if(HAS_CBP(mb_type)){
728 s->dsp.clear_blocks(s->block[0]);
729 cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
730 if(s->mb_intra){
731 dquant = IS_QUANT(mb_type);
732 goto intra;
733 }
734
735 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
736
737 if (cbpy < 0){
738 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
739 return -1;
740 }
741
742 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
743 cbpy ^= 0xF;
744
745 cbp = (cbpc & 3) | (cbpy << 2);
746 }else
747 cbp=0;
748
749 assert(!s->mb_intra);
750
751 if(IS_QUANT(mb_type)){
752 h263_decode_dquant(s);
753 }
754
755 if(IS_DIRECT(mb_type)){
756 s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
757 mb_type |= ff_mpeg4_set_direct_mv(s, 0, 0);
758 }else{
759 s->mv_dir = 0;
760 s->mv_type= MV_TYPE_16X16;
761//FIXME UMV
762
763 if(USES_LIST(mb_type, 0)){
764 int16_t *mot_val= h263_pred_motion(s, 0, 0, &mx, &my);
765 s->mv_dir = MV_DIR_FORWARD;
766
767 mx = h263_decode_motion(s, mx, 1);
768 my = h263_decode_motion(s, my, 1);
769
770 s->mv[0][0][0] = mx;
771 s->mv[0][0][1] = my;
772 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
773 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
774 }
775
776 if(USES_LIST(mb_type, 1)){
777 int16_t *mot_val= h263_pred_motion(s, 0, 1, &mx, &my);
778 s->mv_dir |= MV_DIR_BACKWARD;
779
780 mx = h263_decode_motion(s, mx, 1);
781 my = h263_decode_motion(s, my, 1);
782
783 s->mv[1][0][0] = mx;
784 s->mv[1][0][1] = my;
785 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
786 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
787 }
788 }
789
657ccb5a 790 s->current_picture.f.mb_type[xy] = mb_type;
fc53b6af
MN
791 } else { /* I-Frame */
792 do{
793 cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
794 if (cbpc < 0){
795 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
796 return -1;
797 }
798 }while(cbpc == 8);
799
800 s->dsp.clear_blocks(s->block[0]);
801
802 dquant = cbpc & 4;
803 s->mb_intra = 1;
804intra:
657ccb5a 805 s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
fc53b6af
MN
806 if (s->h263_aic) {
807 s->ac_pred = get_bits1(&s->gb);
808 if(s->ac_pred){
657ccb5a 809 s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
fc53b6af
MN
810
811 s->h263_aic_dir = get_bits1(&s->gb);
812 }
813 }else
814 s->ac_pred = 0;
815
816 if(s->pb_frame && get_bits1(&s->gb))
817 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
818 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
819 if(cbpy<0){
820 av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
821 return -1;
822 }
823 cbp = (cbpc & 3) | (cbpy << 2);
824 if (dquant) {
825 h263_decode_dquant(s);
826 }
827
828 pb_mv_count += !!s->pb_frame;
829 }
830
831 while(pb_mv_count--){
832 h263_decode_motion(s, 0, 1);
833 h263_decode_motion(s, 0, 1);
834 }
835
836 /* decode each block */
837 for (i = 0; i < 6; i++) {
838 if (h263_decode_block(s, block[i], i, cbp&32) < 0)
839 return -1;
840 cbp+=cbp;
841 }
842
843 if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
844 return -1;
845 if(s->obmc && !s->mb_intra){
975a1447 846 if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
fc53b6af
MN
847 preview_obmc(s);
848 }
849end:
850
851 /* per-MB end of slice check */
852 {
853 int v= show_bits(&s->gb, 16);
854
855 if(get_bits_count(&s->gb) + 16 > s->gb.size_in_bits){
856 v>>= get_bits_count(&s->gb) + 16 - s->gb.size_in_bits;
857 }
858
859 if(v==0)
860 return SLICE_END;
861 }
862
863 return SLICE_OK;
864}
865
866/* most is hardcoded. should extend to handle all h263 streams */
867int h263_decode_picture_header(MpegEncContext *s)
868{
869 int format, width, height, i;
870 uint32_t startcode;
871
872 align_get_bits(&s->gb);
873
874 startcode= get_bits(&s->gb, 22-8);
875
876 for(i= get_bits_left(&s->gb); i>24; i-=8) {
877 startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
878
879 if(startcode == 0x20)
880 break;
881 }
882
883 if (startcode != 0x20) {
884 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
885 return -1;
886 }
887 /* temporal reference */
888 i = get_bits(&s->gb, 8); /* picture timestamp */
889 if( (s->picture_number&~0xFF)+i < s->picture_number)
890 i+= 256;
657ccb5a 891 s->current_picture_ptr->f.pts =
fc53b6af
MN
892 s->picture_number= (s->picture_number&~0xFF) + i;
893
894 /* PTYPE starts here */
895 if (get_bits1(&s->gb) != 1) {
896 /* marker */
897 av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n");
898 return -1;
899 }
900 if (get_bits1(&s->gb) != 0) {
901 av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
902 return -1; /* h263 id */
903 }
904 skip_bits1(&s->gb); /* split screen off */
905 skip_bits1(&s->gb); /* camera off */
906 skip_bits1(&s->gb); /* freeze picture release off */
907
908 format = get_bits(&s->gb, 3);
909 /*
910 0 forbidden
911 1 sub-QCIF
912 10 QCIF
913 7 extended PTYPE (PLUSPTYPE)
914 */
915
916 if (format != 7 && format != 6) {
917 s->h263_plus = 0;
918 /* H.263v1 */
919 width = h263_format[format][0];
920 height = h263_format[format][1];
921 if (!width)
922 return -1;
923
975a1447 924 s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
fc53b6af
MN
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->time_base= (AVRational){1001, 30000};
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);
dfd2a005 954 av_dlog(s->avctx, "ufep=1, format: %d\n", format);
fc53b6af
MN
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){
975a1447
SS
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
fc53b6af
MN
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);
dfd2a005 1005 av_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
fc53b6af
MN
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;
dfd2a005 1018 av_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
fc53b6af
MN
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 = h263_format[format][0];
1028 height = 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->time_base.den= 1800000;
1039 s->avctx->time_base.num= 1000 + get_bits1(&s->gb);
1040 s->avctx->time_base.num*= get_bits(&s->gb, 7);
1041 if(s->avctx->time_base.num == 0){
1042 av_log(s, AV_LOG_ERROR, "zero framerate\n");
1043 return -1;
1044 }
1045 gcd= av_gcd(s->avctx->time_base.den, s->avctx->time_base.num);
1046 s->avctx->time_base.den /= gcd;
1047 s->avctx->time_base.num /= gcd;
1048 }else{
1049 s->avctx->time_base= (AVRational){1001, 30000};
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 s->mb_width = (s->width + 15) / 16;
1076 s->mb_height = (s->height + 15) / 16;
1077 s->mb_num = s->mb_width * s->mb_height;
1078
1079 if (s->pb_frame) {
1080 skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1081 if (s->custom_pcf)
1082 skip_bits(&s->gb, 2); //extended Temporal reference
1083 skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1084 }
1085
1086 /* PEI */
1087 while (get_bits1(&s->gb) != 0) {
1088 skip_bits(&s->gb, 8);
1089 }
1090
1091 if(s->h263_slice_structured){
1092 if (get_bits1(&s->gb) != 1) {
1093 av_log(s->avctx, AV_LOG_ERROR, "SEPB1 marker missing\n");
1094 return -1;
1095 }
1096
1097 ff_h263_decode_mba(s);
1098
1099 if (get_bits1(&s->gb) != 1) {
1100 av_log(s->avctx, AV_LOG_ERROR, "SEPB2 marker missing\n");
1101 return -1;
1102 }
1103 }
1104 s->f_code = 1;
1105
1106 if(s->h263_aic){
1107 s->y_dc_scale_table=
1108 s->c_dc_scale_table= ff_aic_dc_scale_table;
1109 }else{
1110 s->y_dc_scale_table=
1111 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1112 }
1113
1114 ff_h263_show_pict_info(s);
975a1447 1115 if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO")){
fc53b6af
MN
1116 int i,j;
1117 for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1118 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1119 for(i=0; i<13; i++){
1120 for(j=0; j<3; j++){
1121 int v= get_bits(&s->gb, 8);
1122 v |= get_sbits(&s->gb, 8)<<8;
1123 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1124 }
1125 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1126 }
1127 for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1128 }
1129
1130 return 0;
1131}