2 * ITU H.263 bitstream decoder
3 * Copyright (c) 2000,2001 Fabrice Bellard
5 * Copyright (c) 2001 Juan J. Sierralta P
6 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
8 * This file is part of FFmpeg.
10 * FFmpeg 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.
15 * FFmpeg 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.
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
30 #define UNCHECKED_BITSTREAM_READER 1
33 #include "libavutil/attributes.h"
34 #include "libavutil/imgutils.h"
35 #include "libavutil/internal.h"
36 #include "libavutil/mathematics.h"
37 #include "libavutil/mem_internal.h"
39 #include "mpegvideo.h"
44 #include "mpegutils.h"
48 #include "mpeg4video.h"
49 #include "mpegvideodata.h"
51 // The defines below define the number of bits that are read at once for
52 // reading vlc values. Changing these may improve speed and data cache needs
53 // be aware though that decreasing them may need the number of stages that is
54 // passed to get_vlc* to be increased.
55 #define H263_MBTYPE_B_VLC_BITS 6
56 #define CBPC_B_VLC_BITS 3
58 static const int h263_mb_type_b_map[15]= {
59 MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
60 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
61 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
62 MB_TYPE_L0 | MB_TYPE_16x16,
63 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_16x16,
64 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
65 MB_TYPE_L1 | MB_TYPE_16x16,
66 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_16x16,
67 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
68 MB_TYPE_L0L1 | MB_TYPE_16x16,
69 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_16x16,
70 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
72 MB_TYPE_INTRA4x4 | MB_TYPE_CBP,
73 MB_TYPE_INTRA4x4 | MB_TYPE_CBP | MB_TYPE_QUANT,
76 void ff_h263_show_pict_info(MpegEncContext *s){
77 if(s->avctx->debug&FF_DEBUG_PICT_INFO){
78 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",
79 s->qscale, av_get_picture_type_char(s->pict_type),
80 s->gb.size_in_bits, 1-s->no_rounding,
82 s->umvplus ? " UMV" : "",
83 s->h263_long_vectors ? " LONG" : "",
84 s->h263_plus ? " +" : "",
85 s->h263_aic ? " AIC" : "",
86 s->alt_inter_vlc ? " AIV" : "",
87 s->modified_quant ? " MQ" : "",
88 s->loop_filter ? " LOOP" : "",
89 s->h263_slice_structured ? " SS" : "",
90 s->avctx->framerate.num, s->avctx->framerate.den
95 /***********************************************/
98 VLC ff_h263_intra_MCBPC_vlc;
99 VLC ff_h263_inter_MCBPC_vlc;
100 VLC ff_h263_cbpy_vlc;
102 static VLC h263_mbtype_b_vlc;
103 static VLC cbpc_b_vlc;
107 /* XXX: find a better solution to handle static init */
108 av_cold void ff_h263_decode_init_vlc(void)
110 static volatile int done = 0;
113 INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
114 ff_h263_intra_MCBPC_bits, 1, 1,
115 ff_h263_intra_MCBPC_code, 1, 1, 72);
116 INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
117 ff_h263_inter_MCBPC_bits, 1, 1,
118 ff_h263_inter_MCBPC_code, 1, 1, 198);
119 INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
120 &ff_h263_cbpy_tab[0][1], 2, 1,
121 &ff_h263_cbpy_tab[0][0], 2, 1, 64);
122 INIT_VLC_STATIC(&ff_h263_mv_vlc, H263_MV_VLC_BITS, 33,
123 &ff_mvtab[0][1], 2, 1,
124 &ff_mvtab[0][0], 2, 1, 538);
125 ff_h263_init_rl_inter();
126 INIT_VLC_RL(ff_h263_rl_inter, 554);
127 INIT_FIRST_VLC_RL(ff_rl_intra_aic, 554);
128 INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
129 &ff_h263_mbtype_b_tab[0][1], 2, 1,
130 &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
131 INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
132 &ff_cbpc_b_tab[0][1], 2, 1,
133 &ff_cbpc_b_tab[0][0], 2, 1, 8);
138 int ff_h263_decode_mba(MpegEncContext *s)
142 for (i = 0; i < 6; i++)
143 if (s->mb_num - 1 <= ff_mba_max[i])
145 mb_pos = get_bits(&s->gb, ff_mba_length[i]);
146 s->mb_x = mb_pos % s->mb_width;
147 s->mb_y = mb_pos / s->mb_width;
153 * Decode the group of blocks header or slice header.
154 * @return <0 if an error occurred
156 static int h263_decode_gob_header(MpegEncContext *s)
158 unsigned int val, gob_number;
161 /* Check for GOB Start Code */
162 val = show_bits(&s->gb, 16);
166 /* We have a GBSC probably with GSTUFF */
167 skip_bits(&s->gb, 16); /* Drop the zeros */
168 left= get_bits_left(&s->gb);
169 left = FFMIN(left, 32);
170 //MN: we must check the bits left or we might end in an infinite loop (or segfault)
171 for(;left>13; left--){
172 if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
177 if(s->h263_slice_structured){
178 if(check_marker(s->avctx, &s->gb, "before MBA")==0)
181 ff_h263_decode_mba(s);
184 if(check_marker(s->avctx, &s->gb, "after MBA")==0)
187 s->qscale = get_bits(&s->gb, 5); /* SQUANT */
188 if(check_marker(s->avctx, &s->gb, "after SQUANT")==0)
190 skip_bits(&s->gb, 2); /* GFID */
192 gob_number = get_bits(&s->gb, 5); /* GN */
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 */
199 if(s->mb_y >= s->mb_height)
209 * Decode the group of blocks / video packet header / slice header (MPEG-4 Studio).
210 * @return bit position of the resync_marker, or <0 if none was found
212 int ff_h263_resync(MpegEncContext *s){
215 /* In MPEG-4 studio mode look for a new slice startcode
216 * and decode slice header */
217 if(s->codec_id==AV_CODEC_ID_MPEG4 && s->studio_profile) {
218 align_get_bits(&s->gb);
220 while (get_bits_left(&s->gb) >= 32 && show_bits_long(&s->gb, 32) != SLICE_START_CODE) {
224 if (get_bits_left(&s->gb) >= 32 && show_bits_long(&s->gb, 32) == SLICE_START_CODE)
225 return get_bits_count(&s->gb);
230 if(s->codec_id==AV_CODEC_ID_MPEG4){
232 align_get_bits(&s->gb);
235 if(show_bits(&s->gb, 16)==0){
236 pos= get_bits_count(&s->gb);
237 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
238 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
240 ret= h263_decode_gob_header(s);
244 //OK, it's not where it is supposed to be ...
245 s->gb= s->last_resync_gb;
246 align_get_bits(&s->gb);
247 left= get_bits_left(&s->gb);
249 for(;left>16+1+5+5; left-=8){
250 if(show_bits(&s->gb, 16)==0){
251 GetBitContext bak= s->gb;
253 pos= get_bits_count(&s->gb);
254 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
255 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
257 ret= h263_decode_gob_header(s);
263 skip_bits(&s->gb, 8);
269 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
271 int code, val, sign, shift;
272 code = get_vlc2(&s->gb, ff_h263_mv_vlc.table, H263_MV_VLC_BITS, 2);
279 sign = get_bits1(&s->gb);
283 val = (val - 1) << shift;
284 val |= get_bits(&s->gb, shift);
291 /* modulo decoding */
292 if (!s->h263_long_vectors) {
293 val = sign_extend(val, 5 + f_code);
295 /* horrible H.263 long vector mode */
296 if (pred < -31 && val < -63)
298 if (pred > 32 && val > 63)
306 /* Decode RVLC of H.263+ UMV */
307 static int h263p_decode_umotion(MpegEncContext * s, int pred)
311 if (get_bits1(&s->gb)) /* Motion difference = 0 */
314 code = 2 + get_bits1(&s->gb);
316 while (get_bits1(&s->gb))
319 code += get_bits1(&s->gb);
321 avpriv_request_sample(s->avctx, "Huge DMV");
328 code = (sign) ? (pred - code) : (pred + code);
329 ff_tlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
335 * read the next MVs for OBMC. yes this is an ugly hack, feel free to send a patch :)
337 static void preview_obmc(MpegEncContext *s){
338 GetBitContext gb= s->gb;
340 int cbpc, i, pred_x, pred_y, mx, my;
342 const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
343 const int stride= s->b8_stride*2;
346 s->block_index[i]+= 2;
348 s->block_index[i]+= 1;
351 av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
354 if (get_bits1(&s->gb)) {
356 mot_val = s->current_picture.motion_val[0][s->block_index[0]];
357 mot_val[0 ]= mot_val[2 ]=
358 mot_val[0+stride]= mot_val[2+stride]= 0;
359 mot_val[1 ]= mot_val[3 ]=
360 mot_val[1+stride]= mot_val[3+stride]= 0;
362 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
365 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
369 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
371 get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
373 if(s->modified_quant){
374 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
375 else skip_bits(&s->gb, 5);
377 skip_bits(&s->gb, 2);
380 if ((cbpc & 16) == 0) {
381 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
382 /* 16x16 motion prediction */
383 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
385 mx = h263p_decode_umotion(s, pred_x);
387 mx = ff_h263_decode_motion(s, pred_x, 1);
390 my = h263p_decode_umotion(s, pred_y);
392 my = ff_h263_decode_motion(s, pred_y, 1);
394 mot_val[0 ]= mot_val[2 ]=
395 mot_val[0+stride]= mot_val[2+stride]= mx;
396 mot_val[1 ]= mot_val[3 ]=
397 mot_val[1+stride]= mot_val[3+stride]= my;
399 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
401 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
403 mx = h263p_decode_umotion(s, pred_x);
405 mx = ff_h263_decode_motion(s, pred_x, 1);
408 my = h263p_decode_umotion(s, pred_y);
410 my = ff_h263_decode_motion(s, pred_y, 1);
411 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
412 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
421 s->block_index[i]-= 2;
423 s->block_index[i]-= 1;
429 static void h263_decode_dquant(MpegEncContext *s){
430 static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
432 if(s->modified_quant){
433 if(get_bits1(&s->gb))
434 s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
436 s->qscale= get_bits(&s->gb, 5);
438 s->qscale += quant_tab[get_bits(&s->gb, 2)];
439 ff_set_qscale(s, s->qscale);
442 static int h263_decode_block(MpegEncContext * s, int16_t * block,
445 int level, i, j, run;
446 RLTable *rl = &ff_h263_rl_inter;
447 const uint8_t *scan_table;
448 GetBitContext gb= s->gb;
450 scan_table = s->intra_scantable.permutated;
451 if (s->h263_aic && s->mb_intra) {
452 rl = &ff_rl_intra_aic;
456 scan_table = s->intra_v_scantable.permutated; /* left */
458 scan_table = s->intra_h_scantable.permutated; /* top */
460 } else if (s->mb_intra) {
462 if (CONFIG_RV10_DECODER && s->codec_id == AV_CODEC_ID_RV10) {
463 if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
465 component = (n <= 3 ? 0 : n - 4 + 1);
466 level = s->last_dc[component];
467 if (s->rv10_first_dc_coded[component]) {
468 diff = ff_rv_decode_dc(s, n);
472 level = level & 0xff; /* handle wrap round */
473 s->last_dc[component] = level;
475 s->rv10_first_dc_coded[component] = 1;
478 level = get_bits(&s->gb, 8);
483 level = get_bits(&s->gb, 8);
484 if((level&0x7F) == 0){
485 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
486 if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
498 if (s->mb_intra && s->h263_aic)
500 s->block_last_index[n] = i - 1;
505 OPEN_READER(re, &s->gb);
506 i--; // offset by -1 to allow direct indexing of scan_table
508 UPDATE_CACHE(re, &s->gb);
509 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
512 CLOSE_READER(re, &s->gb);
513 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
517 if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
518 int is11 = SHOW_UBITS(re, &s->gb, 1);
519 SKIP_CACHE(re, &s->gb, 1);
520 run = SHOW_UBITS(re, &s->gb, 7) + 1;
522 SKIP_COUNTER(re, &s->gb, 1 + 7);
523 UPDATE_CACHE(re, &s->gb);
524 level = SHOW_SBITS(re, &s->gb, 11);
525 SKIP_COUNTER(re, &s->gb, 11);
527 SKIP_CACHE(re, &s->gb, 7);
528 level = SHOW_SBITS(re, &s->gb, 7);
529 SKIP_COUNTER(re, &s->gb, 1 + 7 + 7);
532 run = SHOW_UBITS(re, &s->gb, 7) + 1;
533 SKIP_CACHE(re, &s->gb, 7);
534 level = (int8_t)SHOW_UBITS(re, &s->gb, 8);
535 SKIP_COUNTER(re, &s->gb, 7 + 8);
537 UPDATE_CACHE(re, &s->gb);
538 if (s->codec_id == AV_CODEC_ID_RV10) {
539 /* XXX: should patch encoder too */
540 level = SHOW_SBITS(re, &s->gb, 12);
541 SKIP_COUNTER(re, &s->gb, 12);
543 level = SHOW_UBITS(re, &s->gb, 5);
544 SKIP_CACHE(re, &s->gb, 5);
545 level |= SHOW_SBITS(re, &s->gb, 6) * (1<<5);
546 SKIP_COUNTER(re, &s->gb, 5 + 6);
551 if (SHOW_UBITS(re, &s->gb, 1))
553 SKIP_COUNTER(re, &s->gb, 1);
557 CLOSE_READER(re, &s->gb);
558 // redo update without last flag, revert -1 offset
559 i = i - run + ((run-1)&63) + 1;
561 // only last marker, no overrun
562 block[scan_table[i]] = level;
565 if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
566 //Looks like a hack but no, it's the way it is supposed to work ...
567 rl = &ff_rl_intra_aic;
570 s->bdsp.clear_block(block);
573 av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
581 if (s->mb_intra && s->h263_aic) {
582 ff_h263_pred_acdc(s, block, n);
585 s->block_last_index[n] = i;
589 static int h263_skip_b_part(MpegEncContext *s, int cbp)
591 LOCAL_ALIGNED_32(int16_t, dblock, [64]);
595 /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
596 * but real value should be restored in order to be used later (in OBMC condition)
599 memcpy(bli, s->block_last_index, sizeof(bli));
601 for (i = 0; i < 6; i++) {
602 if (h263_decode_block(s, dblock, i, cbp&32) < 0)
607 memcpy(s->block_last_index, bli, sizeof(bli));
611 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
615 if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
617 if (pb_frame == 2 && c)
619 } else { // h.263 Annex M improved PB-frame
620 mv = get_unary(gb, 0, 4) + 1;
625 *cbpb = get_bits(gb, 6);
629 #define tab_size ((signed)FF_ARRAY_ELEMS(s->direct_scale_mv[0]))
630 #define tab_bias (tab_size / 2)
631 static inline void set_one_direct_mv(MpegEncContext *s, Picture *p, int i)
633 int xy = s->block_index[i];
634 uint16_t time_pp = s->pp_time;
635 uint16_t time_pb = s->pb_time;
638 p_mx = p->motion_val[0][xy][0];
639 if ((unsigned)(p_mx + tab_bias) < tab_size) {
640 s->mv[0][i][0] = s->direct_scale_mv[0][p_mx + tab_bias];
641 s->mv[1][i][0] = s->direct_scale_mv[1][p_mx + tab_bias];
643 s->mv[0][i][0] = p_mx * time_pb / time_pp;
644 s->mv[1][i][0] = p_mx * (time_pb - time_pp) / time_pp;
646 p_my = p->motion_val[0][xy][1];
647 if ((unsigned)(p_my + tab_bias) < tab_size) {
648 s->mv[0][i][1] = s->direct_scale_mv[0][p_my + tab_bias];
649 s->mv[1][i][1] = s->direct_scale_mv[1][p_my + tab_bias];
651 s->mv[0][i][1] = p_my * time_pb / time_pp;
652 s->mv[1][i][1] = p_my * (time_pb - time_pp) / time_pp;
657 * @return the mb_type
659 static int set_direct_mv(MpegEncContext *s)
661 const int mb_index = s->mb_x + s->mb_y * s->mb_stride;
662 Picture *p = &s->next_picture;
663 int colocated_mb_type = p->mb_type[mb_index];
666 if (s->codec_tag == AV_RL32("U263") && p->f->pict_type == AV_PICTURE_TYPE_I) {
667 p = &s->last_picture;
668 colocated_mb_type = p->mb_type[mb_index];
671 if (IS_8X8(colocated_mb_type)) {
672 s->mv_type = MV_TYPE_8X8;
673 for (i = 0; i < 4; i++)
674 set_one_direct_mv(s, p, i);
675 return MB_TYPE_DIRECT2 | MB_TYPE_8x8 | MB_TYPE_L0L1;
677 set_one_direct_mv(s, p, 0);
680 s->mv[0][3][0] = s->mv[0][0][0];
683 s->mv[0][3][1] = s->mv[0][0][1];
686 s->mv[1][3][0] = s->mv[1][0][0];
689 s->mv[1][3][1] = s->mv[1][0][1];
690 s->mv_type = MV_TYPE_8X8;
691 // Note see prev line
692 return MB_TYPE_DIRECT2 | MB_TYPE_16x16 | MB_TYPE_L0L1;
696 int ff_h263_decode_mb(MpegEncContext *s,
697 int16_t block[6][64])
699 int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
701 const int xy= s->mb_x + s->mb_y * s->mb_stride;
702 int cbpb = 0, pb_mv_count = 0;
704 av_assert2(!s->h263_pred);
706 if (s->pict_type == AV_PICTURE_TYPE_P) {
708 if (get_bits1(&s->gb)) {
712 s->block_last_index[i] = -1;
713 s->mv_dir = MV_DIR_FORWARD;
714 s->mv_type = MV_TYPE_16X16;
715 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
718 s->mb_skipped = !(s->obmc | s->loop_filter);
721 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
723 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
728 s->bdsp.clear_blocks(s->block[0]);
731 s->mb_intra = ((cbpc & 4) != 0);
732 if (s->mb_intra) goto intra;
734 if(s->pb_frame && get_bits1(&s->gb))
735 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
736 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
739 av_log(s->avctx, AV_LOG_ERROR, "cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
743 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
746 cbp = (cbpc & 3) | (cbpy << 2);
748 h263_decode_dquant(s);
751 s->mv_dir = MV_DIR_FORWARD;
752 if ((cbpc & 16) == 0) {
753 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
754 /* 16x16 motion prediction */
755 s->mv_type = MV_TYPE_16X16;
756 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
758 mx = h263p_decode_umotion(s, pred_x);
760 mx = ff_h263_decode_motion(s, pred_x, 1);
766 my = h263p_decode_umotion(s, pred_y);
768 my = ff_h263_decode_motion(s, pred_y, 1);
775 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
776 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
778 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
779 s->mv_type = MV_TYPE_8X8;
781 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
783 mx = h263p_decode_umotion(s, pred_x);
785 mx = ff_h263_decode_motion(s, pred_x, 1);
790 my = h263p_decode_umotion(s, pred_y);
792 my = ff_h263_decode_motion(s, pred_y, 1);
797 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
798 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
803 } else if(s->pict_type==AV_PICTURE_TYPE_B) {
805 const int stride= s->b8_stride;
806 int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
807 int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
808 // const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
811 mot_val0[0 ]= mot_val0[2 ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
812 mot_val0[1 ]= mot_val0[3 ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
813 mot_val1[0 ]= mot_val1[2 ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
814 mot_val1[1 ]= mot_val1[3 ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
817 mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
819 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
823 mb_type= h263_mb_type_b_map[ mb_type ];
826 s->mb_intra = IS_INTRA(mb_type);
827 if(HAS_CBP(mb_type)){
828 s->bdsp.clear_blocks(s->block[0]);
829 cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
831 dquant = IS_QUANT(mb_type);
835 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
838 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
842 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
845 cbp = (cbpc & 3) | (cbpy << 2);
849 av_assert2(!s->mb_intra);
851 if(IS_QUANT(mb_type)){
852 h263_decode_dquant(s);
855 if(IS_DIRECT(mb_type)){
856 s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
857 mb_type |= set_direct_mv(s);
860 s->mv_type= MV_TYPE_16X16;
863 if(USES_LIST(mb_type, 0)){
864 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
865 s->mv_dir = MV_DIR_FORWARD;
868 mx = h263p_decode_umotion(s, pred_x);
870 mx = ff_h263_decode_motion(s, pred_x, 1);
875 my = h263p_decode_umotion(s, pred_y);
877 my = ff_h263_decode_motion(s, pred_y, 1);
881 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
882 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
886 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
887 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
890 if(USES_LIST(mb_type, 1)){
891 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &pred_x, &pred_y);
892 s->mv_dir |= MV_DIR_BACKWARD;
895 mx = h263p_decode_umotion(s, pred_x);
897 mx = ff_h263_decode_motion(s, pred_x, 1);
902 my = h263p_decode_umotion(s, pred_y);
904 my = ff_h263_decode_motion(s, pred_y, 1);
908 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
909 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
913 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
914 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
918 s->current_picture.mb_type[xy] = mb_type;
919 } else { /* I-Frame */
921 cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
923 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
928 s->bdsp.clear_blocks(s->block[0]);
933 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
935 s->ac_pred = get_bits1(&s->gb);
937 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
939 s->h263_aic_dir = get_bits1(&s->gb);
944 if(s->pb_frame && get_bits1(&s->gb))
945 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
946 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
948 av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
951 cbp = (cbpc & 3) | (cbpy << 2);
953 h263_decode_dquant(s);
956 pb_mv_count += !!s->pb_frame;
959 while(pb_mv_count--){
960 ff_h263_decode_motion(s, 0, 1);
961 ff_h263_decode_motion(s, 0, 1);
964 /* decode each block */
965 for (i = 0; i < 6; i++) {
966 if (h263_decode_block(s, block[i], i, cbp&32) < 0)
971 if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
973 if(s->obmc && !s->mb_intra){
974 if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
979 if (get_bits_left(&s->gb) < 0)
980 return AVERROR_INVALIDDATA;
982 /* per-MB end of slice check */
984 int v= show_bits(&s->gb, 16);
986 if (get_bits_left(&s->gb) < 16) {
987 v >>= 16 - get_bits_left(&s->gb);
997 /* Most is hardcoded; should extend to handle all H.263 streams. */
998 int ff_h263_decode_picture_header(MpegEncContext *s)
1000 int format, width, height, i, ret;
1003 align_get_bits(&s->gb);
1005 if (show_bits(&s->gb, 2) == 2 && s->avctx->frame_number == 0) {
1006 av_log(s->avctx, AV_LOG_WARNING, "Header looks like RTP instead of H.263\n");
1009 startcode= get_bits(&s->gb, 22-8);
1011 for(i= get_bits_left(&s->gb); i>24; i-=8) {
1012 startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
1014 if(startcode == 0x20)
1018 if (startcode != 0x20) {
1019 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
1022 /* temporal reference */
1023 i = get_bits(&s->gb, 8); /* picture timestamp */
1025 i -= (i - (s->picture_number & 0xFF) + 128) & ~0xFF;
1027 s->picture_number= (s->picture_number&~0xFF) + i;
1029 /* PTYPE starts here */
1030 if (check_marker(s->avctx, &s->gb, "in PTYPE") != 1) {
1033 if (get_bits1(&s->gb) != 0) {
1034 av_log(s->avctx, AV_LOG_ERROR, "Bad H.263 id\n");
1035 return -1; /* H.263 id */
1037 skip_bits1(&s->gb); /* split screen off */
1038 skip_bits1(&s->gb); /* camera off */
1039 skip_bits1(&s->gb); /* freeze picture release off */
1041 format = get_bits(&s->gb, 3);
1046 7 extended PTYPE (PLUSPTYPE)
1049 if (format != 7 && format != 6) {
1052 width = ff_h263_format[format][0];
1053 height = ff_h263_format[format][1];
1057 s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
1059 s->h263_long_vectors = get_bits1(&s->gb);
1061 if (get_bits1(&s->gb) != 0) {
1062 av_log(s->avctx, AV_LOG_ERROR, "H.263 SAC not supported\n");
1063 return -1; /* SAC: off */
1065 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
1066 s->unrestricted_mv = s->h263_long_vectors || s->obmc;
1068 s->pb_frame = get_bits1(&s->gb);
1069 s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
1070 skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
1074 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1075 s->avctx->framerate = (AVRational){ 30000, 1001 };
1081 ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
1083 /* ufep other than 0 and 1 are reserved */
1086 format = get_bits(&s->gb, 3);
1087 ff_dlog(s->avctx, "ufep=1, format: %d\n", format);
1088 s->custom_pcf= get_bits1(&s->gb);
1089 s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
1090 if (get_bits1(&s->gb) != 0) {
1091 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
1093 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
1094 s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
1095 s->loop_filter= get_bits1(&s->gb);
1096 s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter;
1097 if(s->avctx->lowres)
1100 s->h263_slice_structured= get_bits1(&s->gb);
1101 if (get_bits1(&s->gb) != 0) {
1102 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
1104 if (get_bits1(&s->gb) != 0) {
1105 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
1107 s->alt_inter_vlc= get_bits1(&s->gb);
1108 s->modified_quant= get_bits1(&s->gb);
1109 if(s->modified_quant)
1110 s->chroma_qscale_table= ff_h263_chroma_qscale_table;
1112 skip_bits(&s->gb, 1); /* Prevent start code emulation */
1114 skip_bits(&s->gb, 3); /* Reserved */
1115 } else if (ufep != 0) {
1116 av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
1121 s->pict_type = get_bits(&s->gb, 3);
1122 switch(s->pict_type){
1123 case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
1124 case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
1125 case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
1126 case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
1127 case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
1131 skip_bits(&s->gb, 2);
1132 s->no_rounding = get_bits1(&s->gb);
1133 skip_bits(&s->gb, 4);
1135 /* Get the picture dimensions */
1138 /* Custom Picture Format (CPFMT) */
1139 s->aspect_ratio_info = get_bits(&s->gb, 4);
1140 ff_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
1145 3 - 10:11 (525-type 4:3)
1146 4 - 16:11 (CIF 16:9)
1147 5 - 40:33 (525-type 16:9)
1150 width = (get_bits(&s->gb, 9) + 1) * 4;
1151 check_marker(s->avctx, &s->gb, "in dimensions");
1152 height = get_bits(&s->gb, 9) * 4;
1153 ff_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1154 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1155 /* expected dimensions */
1156 s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1157 s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1159 s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1162 width = ff_h263_format[format][0];
1163 height = ff_h263_format[format][1];
1164 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1166 s->avctx->sample_aspect_ratio.den <<= s->ehc_mode;
1167 if ((width == 0) || (height == 0))
1174 s->avctx->framerate.num = 1800000;
1175 s->avctx->framerate.den = 1000 + get_bits1(&s->gb);
1176 s->avctx->framerate.den *= get_bits(&s->gb, 7);
1177 if(s->avctx->framerate.den == 0){
1178 av_log(s, AV_LOG_ERROR, "zero framerate\n");
1181 gcd= av_gcd(s->avctx->framerate.den, s->avctx->framerate.num);
1182 s->avctx->framerate.den /= gcd;
1183 s->avctx->framerate.num /= gcd;
1185 s->avctx->framerate = (AVRational){ 30000, 1001 };
1190 skip_bits(&s->gb, 2); //extended Temporal reference
1195 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
1198 if(s->h263_slice_structured){
1199 if (get_bits1(&s->gb) != 0) {
1200 av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
1202 if (get_bits1(&s->gb) != 0) {
1203 av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1206 if (s->pict_type == AV_PICTURE_TYPE_B) {
1207 skip_bits(&s->gb, 4); //ELNUM
1209 skip_bits(&s->gb, 4); // RLNUM
1214 s->qscale = get_bits(&s->gb, 5);
1217 if ((ret = av_image_check_size(s->width, s->height, 0, s)) < 0)
1220 if (!(s->avctx->flags2 & AV_CODEC_FLAG2_CHUNKS)) {
1221 if ((s->width * s->height / 256 / 8) > get_bits_left(&s->gb))
1222 return AVERROR_INVALIDDATA;
1225 s->mb_width = (s->width + 15) / 16;
1226 s->mb_height = (s->height + 15) / 16;
1227 s->mb_num = s->mb_width * s->mb_height;
1230 skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1232 skip_bits(&s->gb, 2); //extended Temporal reference
1233 skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1236 if (s->pict_type!=AV_PICTURE_TYPE_B) {
1237 s->time = s->picture_number;
1238 s->pp_time = s->time - s->last_non_b_time;
1239 s->last_non_b_time = s->time;
1241 s->time = s->picture_number;
1242 s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
1243 if (s->pp_time <=s->pb_time ||
1244 s->pp_time <= s->pp_time - s->pb_time ||
1249 ff_mpeg4_init_direct_mv(s);
1253 if (skip_1stop_8data_bits(&s->gb) < 0)
1254 return AVERROR_INVALIDDATA;
1256 if(s->h263_slice_structured){
1257 if (check_marker(s->avctx, &s->gb, "SEPB1") != 1) {
1261 ff_h263_decode_mba(s);
1263 if (check_marker(s->avctx, &s->gb, "SEPB2") != 1) {
1269 if (s->pict_type == AV_PICTURE_TYPE_B)
1273 s->y_dc_scale_table=
1274 s->c_dc_scale_table= ff_aic_dc_scale_table;
1276 s->y_dc_scale_table=
1277 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1280 ff_h263_show_pict_info(s);
1281 if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
1283 for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1284 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1285 for(i=0; i<13; i++){
1287 int v= get_bits(&s->gb, 8);
1288 v |= get_sbits(&s->gb, 8) * (1 << 8);
1289 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1291 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1293 for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));