2 * ITU H263 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/internal.h"
35 #include "libavutil/mathematics.h"
37 #include "mpegvideo.h"
40 #include "mpegutils.h"
43 #include "mpeg4video.h"
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.
50 #define H263_MBTYPE_B_VLC_BITS 6
51 #define CBPC_B_VLC_BITS 3
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,
67 MB_TYPE_INTRA4x4 | MB_TYPE_CBP,
68 MB_TYPE_INTRA4x4 | MB_TYPE_CBP | MB_TYPE_QUANT,
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,
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->time_base.den, s->avctx->time_base.num
90 /***********************************************/
93 VLC ff_h263_intra_MCBPC_vlc;
94 VLC ff_h263_inter_MCBPC_vlc;
97 static VLC h263_mbtype_b_vlc;
98 static VLC cbpc_b_vlc;
102 /* XXX: find a better solution to handle static init */
103 av_cold void ff_h263_decode_init_vlc(void)
105 static volatile int done = 0;
108 INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
109 ff_h263_intra_MCBPC_bits, 1, 1,
110 ff_h263_intra_MCBPC_code, 1, 1, 72);
111 INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
112 ff_h263_inter_MCBPC_bits, 1, 1,
113 ff_h263_inter_MCBPC_code, 1, 1, 198);
114 INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
115 &ff_h263_cbpy_tab[0][1], 2, 1,
116 &ff_h263_cbpy_tab[0][0], 2, 1, 64);
117 INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
118 &ff_mvtab[0][1], 2, 1,
119 &ff_mvtab[0][0], 2, 1, 538);
120 ff_init_rl(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
121 ff_init_rl(&ff_rl_intra_aic, ff_h263_static_rl_table_store[1]);
122 INIT_VLC_RL(ff_h263_rl_inter, 554);
123 INIT_VLC_RL(ff_rl_intra_aic, 554);
124 INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
125 &ff_h263_mbtype_b_tab[0][1], 2, 1,
126 &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
127 INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
128 &ff_cbpc_b_tab[0][1], 2, 1,
129 &ff_cbpc_b_tab[0][0], 2, 1, 8);
134 int ff_h263_decode_mba(MpegEncContext *s)
139 if(s->mb_num-1 <= ff_mba_max[i]) break;
141 mb_pos= get_bits(&s->gb, ff_mba_length[i]);
142 s->mb_x= mb_pos % s->mb_width;
143 s->mb_y= mb_pos / s->mb_width;
149 * Decode the group of blocks header or slice header.
150 * @return <0 if an error occurred
152 static int h263_decode_gob_header(MpegEncContext *s)
154 unsigned int val, gob_number;
157 /* Check for GOB Start Code */
158 val = show_bits(&s->gb, 16);
162 /* We have a GBSC probably with GSTUFF */
163 skip_bits(&s->gb, 16); /* Drop the zeros */
164 left= get_bits_left(&s->gb);
165 //MN: we must check the bits left or we might end in a infinite loop (or segfault)
166 for(;left>13; left--){
167 if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
172 if(s->h263_slice_structured){
173 if(get_bits1(&s->gb)==0)
176 ff_h263_decode_mba(s);
179 if(get_bits1(&s->gb)==0)
182 s->qscale = get_bits(&s->gb, 5); /* SQUANT */
183 if(get_bits1(&s->gb)==0)
185 skip_bits(&s->gb, 2); /* GFID */
187 gob_number = get_bits(&s->gb, 5); /* GN */
189 s->mb_y= s->gob_index* gob_number;
190 skip_bits(&s->gb, 2); /* GFID */
191 s->qscale = get_bits(&s->gb, 5); /* GQUANT */
194 if(s->mb_y >= s->mb_height)
204 * Decode the group of blocks / video packet header.
205 * @return bit position of the resync_marker, or <0 if none was found
207 int ff_h263_resync(MpegEncContext *s){
210 if(s->codec_id==AV_CODEC_ID_MPEG4){
212 align_get_bits(&s->gb);
215 if(show_bits(&s->gb, 16)==0){
216 pos= get_bits_count(&s->gb);
217 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
218 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
220 ret= h263_decode_gob_header(s);
224 //OK, it's not where it is supposed to be ...
225 s->gb= s->last_resync_gb;
226 align_get_bits(&s->gb);
227 left= get_bits_left(&s->gb);
229 for(;left>16+1+5+5; left-=8){
230 if(show_bits(&s->gb, 16)==0){
231 GetBitContext bak= s->gb;
233 pos= get_bits_count(&s->gb);
234 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
235 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
237 ret= h263_decode_gob_header(s);
243 skip_bits(&s->gb, 8);
249 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
251 int code, val, sign, shift;
252 code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
259 sign = get_bits1(&s->gb);
263 val = (val - 1) << shift;
264 val |= get_bits(&s->gb, shift);
271 /* modulo decoding */
272 if (!s->h263_long_vectors) {
273 val = sign_extend(val, 5 + f_code);
275 /* horrible h263 long vector mode */
276 if (pred < -31 && val < -63)
278 if (pred > 32 && val > 63)
286 /* Decode RVLC of H.263+ UMV */
287 static int h263p_decode_umotion(MpegEncContext * s, int pred)
291 if (get_bits1(&s->gb)) /* Motion difference = 0 */
294 code = 2 + get_bits1(&s->gb);
296 while (get_bits1(&s->gb))
299 code += get_bits1(&s->gb);
304 code = (sign) ? (pred - code) : (pred + code);
305 av_dlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
311 * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :)
313 static void preview_obmc(MpegEncContext *s){
314 GetBitContext gb= s->gb;
316 int cbpc, i, pred_x, pred_y, mx, my;
318 const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
319 const int stride= s->b8_stride*2;
322 s->block_index[i]+= 2;
324 s->block_index[i]+= 1;
327 av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
330 if (get_bits1(&s->gb)) {
332 mot_val = s->current_picture.motion_val[0][s->block_index[0]];
333 mot_val[0 ]= mot_val[2 ]=
334 mot_val[0+stride]= mot_val[2+stride]= 0;
335 mot_val[1 ]= mot_val[3 ]=
336 mot_val[1+stride]= mot_val[3+stride]= 0;
338 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
341 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
345 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
347 get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
349 if(s->modified_quant){
350 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
351 else skip_bits(&s->gb, 5);
353 skip_bits(&s->gb, 2);
356 if ((cbpc & 16) == 0) {
357 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
358 /* 16x16 motion prediction */
359 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
361 mx = h263p_decode_umotion(s, pred_x);
363 mx = ff_h263_decode_motion(s, pred_x, 1);
366 my = h263p_decode_umotion(s, pred_y);
368 my = ff_h263_decode_motion(s, pred_y, 1);
370 mot_val[0 ]= mot_val[2 ]=
371 mot_val[0+stride]= mot_val[2+stride]= mx;
372 mot_val[1 ]= mot_val[3 ]=
373 mot_val[1+stride]= mot_val[3+stride]= my;
375 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
377 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
379 mx = h263p_decode_umotion(s, pred_x);
381 mx = ff_h263_decode_motion(s, pred_x, 1);
384 my = h263p_decode_umotion(s, pred_y);
386 my = ff_h263_decode_motion(s, pred_y, 1);
387 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
388 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
397 s->block_index[i]-= 2;
399 s->block_index[i]-= 1;
405 static void h263_decode_dquant(MpegEncContext *s){
406 static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
408 if(s->modified_quant){
409 if(get_bits1(&s->gb))
410 s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
412 s->qscale= get_bits(&s->gb, 5);
414 s->qscale += quant_tab[get_bits(&s->gb, 2)];
415 ff_set_qscale(s, s->qscale);
418 static int h263_decode_block(MpegEncContext * s, int16_t * block,
421 int code, level, i, j, last, run;
422 RLTable *rl = &ff_h263_rl_inter;
423 const uint8_t *scan_table;
424 GetBitContext gb= s->gb;
426 scan_table = s->intra_scantable.permutated;
427 if (s->h263_aic && s->mb_intra) {
428 rl = &ff_rl_intra_aic;
432 scan_table = s->intra_v_scantable.permutated; /* left */
434 scan_table = s->intra_h_scantable.permutated; /* top */
436 } else if (s->mb_intra) {
438 if(s->codec_id == AV_CODEC_ID_RV10){
439 #if CONFIG_RV10_DECODER
440 if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
442 component = (n <= 3 ? 0 : n - 4 + 1);
443 level = s->last_dc[component];
444 if (s->rv10_first_dc_coded[component]) {
445 diff = ff_rv_decode_dc(s, n);
449 level = level & 0xff; /* handle wrap round */
450 s->last_dc[component] = level;
452 s->rv10_first_dc_coded[component] = 1;
455 level = get_bits(&s->gb, 8);
461 level = get_bits(&s->gb, 8);
462 if((level&0x7F) == 0){
463 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
464 if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
476 if (s->mb_intra && s->h263_aic)
478 s->block_last_index[n] = i - 1;
483 code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
485 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
490 if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
491 ff_flv2_decode_ac_esc(&s->gb, &level, &run, &last);
493 last = get_bits1(&s->gb);
494 run = get_bits(&s->gb, 6);
495 level = (int8_t)get_bits(&s->gb, 8);
497 if (s->codec_id == AV_CODEC_ID_RV10) {
498 /* XXX: should patch encoder too */
499 level = get_sbits(&s->gb, 12);
501 level = get_bits(&s->gb, 5);
502 level |= get_sbits(&s->gb, 6)<<5;
507 run = rl->table_run[code];
508 level = rl->table_level[code];
509 last = code >= rl->last;
510 if (get_bits1(&s->gb))
515 if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
516 //Looks like a hack but no, it's the way it is supposed to work ...
517 rl = &ff_rl_intra_aic;
520 s->bdsp.clear_block(block);
523 av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
533 if (s->mb_intra && s->h263_aic) {
534 ff_h263_pred_acdc(s, block, n);
537 s->block_last_index[n] = i;
541 static int h263_skip_b_part(MpegEncContext *s, int cbp)
543 LOCAL_ALIGNED_16(int16_t, dblock, [64]);
547 /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
548 * but real value should be restored in order to be used later (in OBMC condition)
551 memcpy(bli, s->block_last_index, sizeof(bli));
553 for (i = 0; i < 6; i++) {
554 if (h263_decode_block(s, dblock, i, cbp&32) < 0)
559 memcpy(s->block_last_index, bli, sizeof(bli));
563 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
567 if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
569 if (pb_frame == 2 && c)
571 } else { // h.263 Annex M improved PB-frame
572 mv = get_unary(gb, 0, 4) + 1;
577 *cbpb = get_bits(gb, 6);
581 int ff_h263_decode_mb(MpegEncContext *s,
582 int16_t block[6][64])
584 int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
586 const int xy= s->mb_x + s->mb_y * s->mb_stride;
587 int cbpb = 0, pb_mv_count = 0;
589 av_assert2(!s->h263_pred);
591 if (s->pict_type == AV_PICTURE_TYPE_P) {
593 if (get_bits1(&s->gb)) {
597 s->block_last_index[i] = -1;
598 s->mv_dir = MV_DIR_FORWARD;
599 s->mv_type = MV_TYPE_16X16;
600 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
603 s->mb_skipped = !(s->obmc | s->loop_filter);
606 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
608 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
613 s->bdsp.clear_blocks(s->block[0]);
616 s->mb_intra = ((cbpc & 4) != 0);
617 if (s->mb_intra) goto intra;
619 if(s->pb_frame && get_bits1(&s->gb))
620 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
621 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
623 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
626 cbp = (cbpc & 3) | (cbpy << 2);
628 h263_decode_dquant(s);
631 s->mv_dir = MV_DIR_FORWARD;
632 if ((cbpc & 16) == 0) {
633 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
634 /* 16x16 motion prediction */
635 s->mv_type = MV_TYPE_16X16;
636 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
638 mx = h263p_decode_umotion(s, pred_x);
640 mx = ff_h263_decode_motion(s, pred_x, 1);
646 my = h263p_decode_umotion(s, pred_y);
648 my = ff_h263_decode_motion(s, pred_y, 1);
655 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
656 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
658 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
659 s->mv_type = MV_TYPE_8X8;
661 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
663 mx = h263p_decode_umotion(s, pred_x);
665 mx = ff_h263_decode_motion(s, pred_x, 1);
670 my = h263p_decode_umotion(s, pred_y);
672 my = ff_h263_decode_motion(s, pred_y, 1);
677 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
678 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
683 } else if(s->pict_type==AV_PICTURE_TYPE_B) {
685 const int stride= s->b8_stride;
686 int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
687 int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
688 // const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
691 mot_val0[0 ]= mot_val0[2 ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
692 mot_val0[1 ]= mot_val0[3 ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
693 mot_val1[0 ]= mot_val1[2 ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
694 mot_val1[1 ]= mot_val1[3 ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
697 mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
699 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
703 mb_type= h263_mb_type_b_map[ mb_type ];
706 s->mb_intra = IS_INTRA(mb_type);
707 if(HAS_CBP(mb_type)){
708 s->bdsp.clear_blocks(s->block[0]);
709 cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
711 dquant = IS_QUANT(mb_type);
715 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
718 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
722 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
725 cbp = (cbpc & 3) | (cbpy << 2);
729 av_assert2(!s->mb_intra);
731 if(IS_QUANT(mb_type)){
732 h263_decode_dquant(s);
735 if(IS_DIRECT(mb_type)){
736 s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
737 mb_type |= ff_mpeg4_set_direct_mv(s, 0, 0);
740 s->mv_type= MV_TYPE_16X16;
743 if(USES_LIST(mb_type, 0)){
744 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &mx, &my);
745 s->mv_dir = MV_DIR_FORWARD;
747 mx = ff_h263_decode_motion(s, mx, 1);
748 my = ff_h263_decode_motion(s, my, 1);
752 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
753 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
756 if(USES_LIST(mb_type, 1)){
757 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &mx, &my);
758 s->mv_dir |= MV_DIR_BACKWARD;
760 mx = ff_h263_decode_motion(s, mx, 1);
761 my = ff_h263_decode_motion(s, my, 1);
765 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
766 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
770 s->current_picture.mb_type[xy] = mb_type;
771 } else { /* I-Frame */
773 cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
775 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
780 s->bdsp.clear_blocks(s->block[0]);
785 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
787 s->ac_pred = get_bits1(&s->gb);
789 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
791 s->h263_aic_dir = get_bits1(&s->gb);
796 if(s->pb_frame && get_bits1(&s->gb))
797 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
798 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
800 av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
803 cbp = (cbpc & 3) | (cbpy << 2);
805 h263_decode_dquant(s);
808 pb_mv_count += !!s->pb_frame;
811 while(pb_mv_count--){
812 ff_h263_decode_motion(s, 0, 1);
813 ff_h263_decode_motion(s, 0, 1);
816 /* decode each block */
817 for (i = 0; i < 6; i++) {
818 if (h263_decode_block(s, block[i], i, cbp&32) < 0)
823 if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
825 if(s->obmc && !s->mb_intra){
826 if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
831 /* per-MB end of slice check */
833 int v= show_bits(&s->gb, 16);
835 if (get_bits_left(&s->gb) < 16) {
836 v >>= 16 - get_bits_left(&s->gb);
846 /* most is hardcoded. should extend to handle all h263 streams */
847 int ff_h263_decode_picture_header(MpegEncContext *s)
849 int format, width, height, i;
852 align_get_bits(&s->gb);
854 if (show_bits(&s->gb, 2) == 2 && s->avctx->frame_number == 0) {
855 av_log(s->avctx, AV_LOG_WARNING, "Header looks like RTP instead of H.263\n");
858 startcode= get_bits(&s->gb, 22-8);
860 for(i= get_bits_left(&s->gb); i>24; i-=8) {
861 startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
863 if(startcode == 0x20)
867 if (startcode != 0x20) {
868 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
871 /* temporal reference */
872 i = get_bits(&s->gb, 8); /* picture timestamp */
873 if( (s->picture_number&~0xFF)+i < s->picture_number)
875 s->picture_number= (s->picture_number&~0xFF) + i;
877 /* PTYPE starts here */
878 if (get_bits1(&s->gb) != 1) {
880 av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n");
883 if (get_bits1(&s->gb) != 0) {
884 av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
885 return -1; /* h263 id */
887 skip_bits1(&s->gb); /* split screen off */
888 skip_bits1(&s->gb); /* camera off */
889 skip_bits1(&s->gb); /* freeze picture release off */
891 format = get_bits(&s->gb, 3);
896 7 extended PTYPE (PLUSPTYPE)
899 if (format != 7 && format != 6) {
902 width = ff_h263_format[format][0];
903 height = ff_h263_format[format][1];
907 s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
909 s->h263_long_vectors = get_bits1(&s->gb);
911 if (get_bits1(&s->gb) != 0) {
912 av_log(s->avctx, AV_LOG_ERROR, "H263 SAC not supported\n");
913 return -1; /* SAC: off */
915 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
916 s->unrestricted_mv = s->h263_long_vectors || s->obmc;
918 s->pb_frame = get_bits1(&s->gb);
919 s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
920 skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
924 s->avctx->sample_aspect_ratio= (AVRational){12,11};
925 s->avctx->time_base= (AVRational){1001, 30000};
931 ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
933 /* ufep other than 0 and 1 are reserved */
936 format = get_bits(&s->gb, 3);
937 av_dlog(s->avctx, "ufep=1, format: %d\n", format);
938 s->custom_pcf= get_bits1(&s->gb);
939 s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
940 if (get_bits1(&s->gb) != 0) {
941 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
943 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
944 s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
945 s->loop_filter= get_bits1(&s->gb);
946 s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter;
950 s->h263_slice_structured= get_bits1(&s->gb);
951 if (get_bits1(&s->gb) != 0) {
952 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
954 if (get_bits1(&s->gb) != 0) {
955 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
957 s->alt_inter_vlc= get_bits1(&s->gb);
958 s->modified_quant= get_bits1(&s->gb);
959 if(s->modified_quant)
960 s->chroma_qscale_table= ff_h263_chroma_qscale_table;
962 skip_bits(&s->gb, 1); /* Prevent start code emulation */
964 skip_bits(&s->gb, 3); /* Reserved */
965 } else if (ufep != 0) {
966 av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
971 s->pict_type = get_bits(&s->gb, 3);
972 switch(s->pict_type){
973 case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
974 case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
975 case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
976 case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
977 case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
981 skip_bits(&s->gb, 2);
982 s->no_rounding = get_bits1(&s->gb);
983 skip_bits(&s->gb, 4);
985 /* Get the picture dimensions */
988 /* Custom Picture Format (CPFMT) */
989 s->aspect_ratio_info = get_bits(&s->gb, 4);
990 av_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
995 3 - 10:11 (525-type 4:3)
997 5 - 40:33 (525-type 16:9)
1000 width = (get_bits(&s->gb, 9) + 1) * 4;
1002 height = get_bits(&s->gb, 9) * 4;
1003 av_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1004 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1005 /* aspected dimensions */
1006 s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1007 s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1009 s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1012 width = ff_h263_format[format][0];
1013 height = ff_h263_format[format][1];
1014 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1016 s->avctx->sample_aspect_ratio.den <<= s->ehc_mode;
1017 if ((width == 0) || (height == 0))
1024 s->avctx->time_base.den= 1800000;
1025 s->avctx->time_base.num= 1000 + get_bits1(&s->gb);
1026 s->avctx->time_base.num*= get_bits(&s->gb, 7);
1027 if(s->avctx->time_base.num == 0){
1028 av_log(s, AV_LOG_ERROR, "zero framerate\n");
1031 gcd= av_gcd(s->avctx->time_base.den, s->avctx->time_base.num);
1032 s->avctx->time_base.den /= gcd;
1033 s->avctx->time_base.num /= gcd;
1035 s->avctx->time_base= (AVRational){1001, 30000};
1040 skip_bits(&s->gb, 2); //extended Temporal reference
1045 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
1048 if(s->h263_slice_structured){
1049 if (get_bits1(&s->gb) != 0) {
1050 av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
1052 if (get_bits1(&s->gb) != 0) {
1053 av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1058 s->qscale = get_bits(&s->gb, 5);
1061 if (s->width == 0 || s->height == 0) {
1062 av_log(s->avctx, AV_LOG_ERROR, "dimensions 0\n");
1065 s->mb_width = (s->width + 15) / 16;
1066 s->mb_height = (s->height + 15) / 16;
1067 s->mb_num = s->mb_width * s->mb_height;
1070 skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1072 skip_bits(&s->gb, 2); //extended Temporal reference
1073 skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1076 if (s->pict_type!=AV_PICTURE_TYPE_B) {
1077 s->time = s->picture_number;
1078 s->pp_time = s->time - s->last_non_b_time;
1079 s->last_non_b_time = s->time;
1081 s->time = s->picture_number;
1082 s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
1083 if (s->pp_time <=s->pb_time ||
1084 s->pp_time <= s->pp_time - s->pb_time ||
1089 ff_mpeg4_init_direct_mv(s);
1093 if (skip_1stop_8data_bits(&s->gb) < 0)
1094 return AVERROR_INVALIDDATA;
1096 if(s->h263_slice_structured){
1097 if (get_bits1(&s->gb) != 1) {
1098 av_log(s->avctx, AV_LOG_ERROR, "SEPB1 marker missing\n");
1102 ff_h263_decode_mba(s);
1104 if (get_bits1(&s->gb) != 1) {
1105 av_log(s->avctx, AV_LOG_ERROR, "SEPB2 marker missing\n");
1112 s->y_dc_scale_table=
1113 s->c_dc_scale_table= ff_aic_dc_scale_table;
1115 s->y_dc_scale_table=
1116 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1119 ff_h263_show_pict_info(s);
1120 if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
1122 for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1123 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1124 for(i=0; i<13; i++){
1126 int v= get_bits(&s->gb, 8);
1127 v |= get_sbits(&s->gb, 8)<<8;
1128 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1130 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1132 for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));