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
35 #include "mpegvideo.h"
40 #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_pict_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 void h263_decode_init_vlc(MpegEncContext *s)
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,
121 &mvtab[0][0], 2, 1, 538);
122 init_rl(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
123 init_rl(&rl_intra_aic, ff_h263_static_rl_table_store[1]);
124 INIT_VLC_RL(ff_h263_rl_inter, 554);
125 INIT_VLC_RL(rl_intra_aic, 554);
126 INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
127 &h263_mbtype_b_tab[0][1], 2, 1,
128 &h263_mbtype_b_tab[0][0], 2, 1, 80);
129 INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
130 &cbpc_b_tab[0][1], 2, 1,
131 &cbpc_b_tab[0][0], 2, 1, 8);
135 int ff_h263_decode_mba(MpegEncContext *s)
140 if(s->mb_num-1 <= ff_mba_max[i]) break;
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;
150 * decodes the group of blocks header or slice header.
151 * @return <0 if an error occurred
153 static int h263_decode_gob_header(MpegEncContext *s)
155 unsigned int val, gfid, gob_number;
158 /* Check for GOB Start Code */
159 val = show_bits(&s->gb, 16);
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 */
173 if(s->h263_slice_structured){
174 if(get_bits1(&s->gb)==0)
177 ff_h263_decode_mba(s);
180 if(get_bits1(&s->gb)==0)
183 s->qscale = get_bits(&s->gb, 5); /* SQUANT */
184 if(get_bits1(&s->gb)==0)
186 gfid = get_bits(&s->gb, 2); /* GFID */
188 gob_number = get_bits(&s->gb, 5); /* GN */
190 s->mb_y= s->gob_index* gob_number;
191 gfid = get_bits(&s->gb, 2); /* GFID */
192 s->qscale = get_bits(&s->gb, 5); /* GQUANT */
195 if(s->mb_y >= s->mb_height)
205 * finds 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
210 const uint8_t *ff_h263_find_resync_marker(const uint8_t *restrict p, const uint8_t * restrict end)
218 if (!p[-1] && p[1]) return p - 1;
219 else if(!p[ 1] && p[2]) return p;
226 * decodes the group of blocks / video packet header.
227 * @return bit position of the resync_marker, or <0 if none was found
229 int ff_h263_resync(MpegEncContext *s){
232 if(s->codec_id==CODEC_ID_MPEG4){
234 align_get_bits(&s->gb);
237 if(show_bits(&s->gb, 16)==0){
238 pos= get_bits_count(&s->gb);
239 if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4)
240 ret= mpeg4_decode_video_packet_header(s);
242 ret= h263_decode_gob_header(s);
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);
251 for(;left>16+1+5+5; left-=8){
252 if(show_bits(&s->gb, 16)==0){
253 GetBitContext bak= s->gb;
255 pos= get_bits_count(&s->gb);
256 if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4)
257 ret= mpeg4_decode_video_packet_header(s);
259 ret= h263_decode_gob_header(s);
265 skip_bits(&s->gb, 8);
271 int h263_decode_motion(MpegEncContext * s, int pred, int f_code)
273 int code, val, sign, shift, l;
274 code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
281 sign = get_bits1(&s->gb);
285 val = (val - 1) << shift;
286 val |= get_bits(&s->gb, shift);
293 /* modulo decoding */
294 if (!s->h263_long_vectors) {
295 l = INT_BIT - 5 - f_code;
298 /* horrible h263 long vector mode */
299 if (pred < -31 && val < -63)
301 if (pred > 32 && val > 63)
309 /* Decodes RVLC of H.263+ UMV */
310 static int h263p_decode_umotion(MpegEncContext * s, int pred)
314 if (get_bits1(&s->gb)) /* Motion difference = 0 */
317 code = 2 + get_bits1(&s->gb);
319 while (get_bits1(&s->gb))
322 code += get_bits1(&s->gb);
327 code = (sign) ? (pred - code) : (pred + code);
328 dprintf(s->avctx,"H.263+ UMV Motion = %d\n", code);
334 * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :)
336 static void preview_obmc(MpegEncContext *s){
337 GetBitContext gb= s->gb;
339 int cbpc, i, pred_x, pred_y, mx, my;
341 const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
342 const int stride= s->b8_stride*2;
345 s->block_index[i]+= 2;
347 s->block_index[i]+= 1;
350 assert(s->pict_type == FF_P_TYPE);
353 if (get_bits1(&s->gb)) {
355 mot_val = s->current_picture.motion_val[0][ s->block_index[0] ];
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;
361 s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
364 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
368 s->current_picture.mb_type[xy]= MB_TYPE_INTRA;
370 get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
372 if(s->modified_quant){
373 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
374 else skip_bits(&s->gb, 5);
376 skip_bits(&s->gb, 2);
379 if ((cbpc & 16) == 0) {
380 s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0;
381 /* 16x16 motion prediction */
382 mot_val= h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
384 mx = h263p_decode_umotion(s, pred_x);
386 mx = h263_decode_motion(s, pred_x, 1);
389 my = h263p_decode_umotion(s, pred_y);
391 my = h263_decode_motion(s, pred_y, 1);
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;
398 s->current_picture.mb_type[xy]= MB_TYPE_8x8 | MB_TYPE_L0;
400 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y);
402 mx = h263p_decode_umotion(s, pred_x);
404 mx = h263_decode_motion(s, pred_x, 1);
407 my = h263p_decode_umotion(s, pred_y);
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 */
420 s->block_index[i]-= 2;
422 s->block_index[i]-= 1;
428 static void h263_decode_dquant(MpegEncContext *s){
429 static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
431 if(s->modified_quant){
432 if(get_bits1(&s->gb))
433 s->qscale= modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
435 s->qscale= get_bits(&s->gb, 5);
437 s->qscale += quant_tab[get_bits(&s->gb, 2)];
438 ff_set_qscale(s, s->qscale);
441 static int h263_decode_block(MpegEncContext * s, DCTELEM * block,
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;
449 scan_table = s->intra_scantable.permutated;
450 if (s->h263_aic && s->mb_intra) {
455 scan_table = s->intra_v_scantable.permutated; /* left */
457 scan_table = s->intra_h_scantable.permutated; /* top */
459 } else if (s->mb_intra) {
461 if(s->codec_id == CODEC_ID_RV10){
462 #if CONFIG_RV10_DECODER
463 if (s->rv10_version == 3 && s->pict_type == FF_I_TYPE) {
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);
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);
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);
487 if(s->error_recognition >= FF_ER_COMPLIANT)
499 if (s->mb_intra && s->h263_aic)
501 s->block_last_index[n] = i - 1;
506 code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
508 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
513 if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
514 ff_flv2_decode_ac_esc(&s->gb, &level, &run, &last);
516 last = get_bits1(&s->gb);
517 run = get_bits(&s->gb, 6);
518 level = (int8_t)get_bits(&s->gb, 8);
520 if (s->codec_id == CODEC_ID_RV10) {
521 /* XXX: should patch encoder too */
522 level = get_sbits(&s->gb, 12);
524 level = get_bits(&s->gb, 5);
525 level |= get_sbits(&s->gb, 6)<<5;
530 run = rl->table_run[code];
531 level = rl->table_level[code];
532 last = code >= rl->last;
533 if (get_bits1(&s->gb))
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 ...
543 s->dsp.clear_block(block);
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);
556 if (s->mb_intra && s->h263_aic) {
557 h263_pred_acdc(s, block, n);
560 s->block_last_index[n] = i;
564 static int h263_skip_b_part(MpegEncContext *s, int cbp)
566 LOCAL_ALIGNED_16(DCTELEM, dblock, [64]);
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)
574 for (i = 0; i < 6; i++) {
575 if (h263_decode_block(s, dblock, i, cbp&32) < 0)
583 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
587 if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
589 if (pb_frame == 2 && c)
591 } else { // h.263 Annex M improved PB-frame
592 mv = get_unary(gb, 0, 4) + 1;
597 *cbpb = get_bits(gb, 6);
601 int ff_h263_decode_mb(MpegEncContext *s,
602 DCTELEM block[6][64])
604 int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
606 const int xy= s->mb_x + s->mb_y * s->mb_stride;
607 int cbpb = 0, pb_mv_count = 0;
609 assert(!s->h263_pred);
611 if (s->pict_type == FF_P_TYPE) {
613 if (get_bits1(&s->gb)) {
617 s->block_last_index[i] = -1;
618 s->mv_dir = MV_DIR_FORWARD;
619 s->mv_type = MV_TYPE_16X16;
620 s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
623 s->mb_skipped = !(s->obmc | s->loop_filter);
626 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
628 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
633 s->dsp.clear_blocks(s->block[0]);
636 s->mb_intra = ((cbpc & 4) != 0);
637 if (s->mb_intra) goto intra;
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);
643 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
646 cbp = (cbpc & 3) | (cbpy << 2);
648 h263_decode_dquant(s);
651 s->mv_dir = MV_DIR_FORWARD;
652 if ((cbpc & 16) == 0) {
653 s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0;
654 /* 16x16 motion prediction */
655 s->mv_type = MV_TYPE_16X16;
656 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
658 mx = h263p_decode_umotion(s, pred_x);
660 mx = h263_decode_motion(s, pred_x, 1);
666 my = h263p_decode_umotion(s, pred_y);
668 my = h263_decode_motion(s, pred_y, 1);
675 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
676 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
678 s->current_picture.mb_type[xy]= MB_TYPE_8x8 | MB_TYPE_L0;
679 s->mv_type = MV_TYPE_8X8;
681 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y);
683 mx = h263p_decode_umotion(s, pred_x);
685 mx = h263_decode_motion(s, pred_x, 1);
690 my = h263p_decode_umotion(s, pred_y);
692 my = h263_decode_motion(s, pred_y, 1);
697 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
698 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
703 } else if(s->pict_type==FF_B_TYPE) {
705 const int stride= s->b8_stride;
706 int16_t *mot_val0 = s->current_picture.motion_val[0][ 2*(s->mb_x + s->mb_y*stride) ];
707 int16_t *mot_val1 = s->current_picture.motion_val[1][ 2*(s->mb_x + s->mb_y*stride) ];
708 // const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
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;
717 mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
719 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
723 mb_type= h263_mb_type_b_map[ mb_type ];
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);
731 dquant = IS_QUANT(mb_type);
735 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
738 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
742 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
745 cbp = (cbpc & 3) | (cbpy << 2);
749 assert(!s->mb_intra);
751 if(IS_QUANT(mb_type)){
752 h263_decode_dquant(s);
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);
760 s->mv_type= MV_TYPE_16X16;
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;
767 mx = h263_decode_motion(s, mx, 1);
768 my = h263_decode_motion(s, my, 1);
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;
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;
780 mx = h263_decode_motion(s, mx, 1);
781 my = h263_decode_motion(s, my, 1);
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;
790 s->current_picture.mb_type[xy]= mb_type;
791 } else { /* I-Frame */
793 cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
795 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
800 s->dsp.clear_blocks(s->block[0]);
805 s->current_picture.mb_type[xy]= MB_TYPE_INTRA;
807 s->ac_pred = get_bits1(&s->gb);
809 s->current_picture.mb_type[xy]= MB_TYPE_INTRA | MB_TYPE_ACPRED;
811 s->h263_aic_dir = get_bits1(&s->gb);
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);
820 av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
823 cbp = (cbpc & 3) | (cbpy << 2);
825 h263_decode_dquant(s);
828 pb_mv_count += !!s->pb_frame;
831 while(pb_mv_count--){
832 h263_decode_motion(s, 0, 1);
833 h263_decode_motion(s, 0, 1);
836 /* decode each block */
837 for (i = 0; i < 6; i++) {
838 if (h263_decode_block(s, block[i], i, cbp&32) < 0)
843 if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
845 if(s->obmc && !s->mb_intra){
846 if(s->pict_type == FF_P_TYPE && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
851 /* per-MB end of slice check */
853 int v= show_bits(&s->gb, 16);
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;
866 /* most is hardcoded. should extend to handle all h263 streams */
867 int h263_decode_picture_header(MpegEncContext *s)
869 int format, width, height, i;
872 align_get_bits(&s->gb);
874 startcode= get_bits(&s->gb, 22-8);
876 for(i= get_bits_left(&s->gb); i>24; i-=8) {
877 startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
879 if(startcode == 0x20)
883 if (startcode != 0x20) {
884 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
887 /* temporal reference */
888 i = get_bits(&s->gb, 8); /* picture timestamp */
889 if( (s->picture_number&~0xFF)+i < s->picture_number)
891 s->current_picture_ptr->pts=
892 s->picture_number= (s->picture_number&~0xFF) + i;
894 /* PTYPE starts here */
895 if (get_bits1(&s->gb) != 1) {
897 av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n");
900 if (get_bits1(&s->gb) != 0) {
901 av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
902 return -1; /* h263 id */
904 skip_bits1(&s->gb); /* split screen off */
905 skip_bits1(&s->gb); /* camera off */
906 skip_bits1(&s->gb); /* freeze picture release off */
908 format = get_bits(&s->gb, 3);
913 7 extended PTYPE (PLUSPTYPE)
916 if (format != 7 && format != 6) {
919 width = h263_format[format][0];
920 height = h263_format[format][1];
924 s->pict_type = FF_I_TYPE + get_bits1(&s->gb);
926 s->h263_long_vectors = get_bits1(&s->gb);
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 */
932 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
933 s->unrestricted_mv = s->h263_long_vectors || s->obmc;
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 */
941 s->avctx->sample_aspect_ratio= (AVRational){12,11};
942 s->avctx->time_base= (AVRational){1001, 30000};
948 ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
950 /* ufep other than 0 and 1 are reserved */
953 format = get_bits(&s->gb, 3);
954 dprintf(s->avctx, "ufep=1, format: %d\n", format);
955 s->custom_pcf= get_bits1(&s->gb);
956 s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
957 if (get_bits1(&s->gb) != 0) {
958 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
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;
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");
969 if (get_bits1(&s->gb) != 0) {
970 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
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;
977 skip_bits(&s->gb, 1); /* Prevent start code emulation */
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);
986 s->pict_type = get_bits(&s->gb, 3);
987 switch(s->pict_type){
988 case 0: s->pict_type= FF_I_TYPE;break;
989 case 1: s->pict_type= FF_P_TYPE;break;
990 case 2: s->pict_type= FF_P_TYPE;s->pb_frame = 3;break;
991 case 3: s->pict_type= FF_B_TYPE;break;
992 case 7: s->pict_type= FF_I_TYPE;break; //ZYGO
996 skip_bits(&s->gb, 2);
997 s->no_rounding = get_bits1(&s->gb);
998 skip_bits(&s->gb, 4);
1000 /* Get the picture dimensions */
1003 /* Custom Picture Format (CPFMT) */
1004 s->aspect_ratio_info = get_bits(&s->gb, 4);
1005 dprintf(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
1010 3 - 10:11 (525-type 4:3)
1011 4 - 16:11 (CIF 16:9)
1012 5 - 40:33 (525-type 16:9)
1015 width = (get_bits(&s->gb, 9) + 1) * 4;
1017 height = get_bits(&s->gb, 9) * 4;
1018 dprintf(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1019 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1020 /* aspected dimensions */
1021 s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1022 s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1024 s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1027 width = h263_format[format][0];
1028 height = h263_format[format][1];
1029 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1031 if ((width == 0) || (height == 0))
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");
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;
1049 s->avctx->time_base= (AVRational){1001, 30000};
1054 skip_bits(&s->gb, 2); //extended Temporal reference
1059 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
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");
1066 if (get_bits1(&s->gb) != 0) {
1067 av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1072 s->qscale = get_bits(&s->gb, 5);
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;
1080 skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1082 skip_bits(&s->gb, 2); //extended Temporal reference
1083 skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1087 while (get_bits1(&s->gb) != 0) {
1088 skip_bits(&s->gb, 8);
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");
1097 ff_h263_decode_mba(s);
1099 if (get_bits1(&s->gb) != 1) {
1100 av_log(s->avctx, AV_LOG_ERROR, "SEPB2 marker missing\n");
1107 s->y_dc_scale_table=
1108 s->c_dc_scale_table= ff_aic_dc_scale_table;
1110 s->y_dc_scale_table=
1111 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1114 ff_h263_show_pict_info(s);
1115 if (s->pict_type == FF_I_TYPE && s->codec_tag == AV_RL32("ZYGO")){
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++){
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);
1125 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1127 for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));