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"
41 #include "mpegutils.h"
44 #include "mpeg4video.h"
45 #include "mpegvideodata.h"
47 // The defines below define the number of bits that are read at once for
48 // reading vlc values. Changing these may improve speed and data cache needs
49 // be aware though that decreasing them may need the number of stages that is
50 // passed to get_vlc* to be increased.
52 #define H263_MBTYPE_B_VLC_BITS 6
53 #define CBPC_B_VLC_BITS 3
55 static const int h263_mb_type_b_map[15]= {
56 MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
57 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
58 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
59 MB_TYPE_L0 | MB_TYPE_16x16,
60 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_16x16,
61 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
62 MB_TYPE_L1 | MB_TYPE_16x16,
63 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_16x16,
64 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
65 MB_TYPE_L0L1 | MB_TYPE_16x16,
66 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_16x16,
67 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
69 MB_TYPE_INTRA4x4 | MB_TYPE_CBP,
70 MB_TYPE_INTRA4x4 | MB_TYPE_CBP | MB_TYPE_QUANT,
73 void ff_h263_show_pict_info(MpegEncContext *s){
74 if(s->avctx->debug&FF_DEBUG_PICT_INFO){
75 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",
76 s->qscale, av_get_picture_type_char(s->pict_type),
77 s->gb.size_in_bits, 1-s->no_rounding,
79 s->umvplus ? " UMV" : "",
80 s->h263_long_vectors ? " LONG" : "",
81 s->h263_plus ? " +" : "",
82 s->h263_aic ? " AIC" : "",
83 s->alt_inter_vlc ? " AIV" : "",
84 s->modified_quant ? " MQ" : "",
85 s->loop_filter ? " LOOP" : "",
86 s->h263_slice_structured ? " SS" : "",
87 s->avctx->framerate.num, s->avctx->framerate.den
92 /***********************************************/
95 VLC ff_h263_intra_MCBPC_vlc;
96 VLC ff_h263_inter_MCBPC_vlc;
99 static VLC h263_mbtype_b_vlc;
100 static VLC cbpc_b_vlc;
104 /* XXX: find a better solution to handle static init */
105 av_cold void ff_h263_decode_init_vlc(void)
107 static volatile int done = 0;
110 INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
111 ff_h263_intra_MCBPC_bits, 1, 1,
112 ff_h263_intra_MCBPC_code, 1, 1, 72);
113 INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
114 ff_h263_inter_MCBPC_bits, 1, 1,
115 ff_h263_inter_MCBPC_code, 1, 1, 198);
116 INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
117 &ff_h263_cbpy_tab[0][1], 2, 1,
118 &ff_h263_cbpy_tab[0][0], 2, 1, 64);
119 INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
120 &ff_mvtab[0][1], 2, 1,
121 &ff_mvtab[0][0], 2, 1, 538);
122 ff_rl_init(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
123 ff_rl_init(&ff_rl_intra_aic, ff_h263_static_rl_table_store[1]);
124 INIT_VLC_RL(ff_h263_rl_inter, 554);
125 INIT_VLC_RL(ff_rl_intra_aic, 554);
126 INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
127 &ff_h263_mbtype_b_tab[0][1], 2, 1,
128 &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
129 INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
130 &ff_cbpc_b_tab[0][1], 2, 1,
131 &ff_cbpc_b_tab[0][0], 2, 1, 8);
136 int ff_h263_decode_mba(MpegEncContext *s)
141 if(s->mb_num-1 <= ff_mba_max[i]) break;
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;
151 * Decode the group of blocks header or slice header.
152 * @return <0 if an error occurred
154 static int h263_decode_gob_header(MpegEncContext *s)
156 unsigned int val, gob_number;
159 /* Check for GOB Start Code */
160 val = show_bits(&s->gb, 16);
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 */
174 if(s->h263_slice_structured){
175 if(check_marker(&s->gb, "before MBA")==0)
178 ff_h263_decode_mba(s);
181 if(check_marker(&s->gb, "after MBA")==0)
184 s->qscale = get_bits(&s->gb, 5); /* SQUANT */
185 if(check_marker(&s->gb, "after SQUANT")==0)
187 skip_bits(&s->gb, 2); /* GFID */
189 gob_number = get_bits(&s->gb, 5); /* GN */
191 s->mb_y= s->gob_index* gob_number;
192 skip_bits(&s->gb, 2); /* GFID */
193 s->qscale = get_bits(&s->gb, 5); /* GQUANT */
196 if(s->mb_y >= s->mb_height)
206 * Decode the group of blocks / video packet header.
207 * @return bit position of the resync_marker, or <0 if none was found
209 int ff_h263_resync(MpegEncContext *s){
212 if(s->codec_id==AV_CODEC_ID_MPEG4){
214 align_get_bits(&s->gb);
217 if(show_bits(&s->gb, 16)==0){
218 pos= get_bits_count(&s->gb);
219 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
220 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
222 ret= h263_decode_gob_header(s);
226 //OK, it's not where it is supposed to be ...
227 s->gb= s->last_resync_gb;
228 align_get_bits(&s->gb);
229 left= get_bits_left(&s->gb);
231 for(;left>16+1+5+5; left-=8){
232 if(show_bits(&s->gb, 16)==0){
233 GetBitContext bak= s->gb;
235 pos= get_bits_count(&s->gb);
236 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
237 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
239 ret= h263_decode_gob_header(s);
245 skip_bits(&s->gb, 8);
251 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
253 int code, val, sign, shift;
254 code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
261 sign = get_bits1(&s->gb);
265 val = (val - 1) << shift;
266 val |= get_bits(&s->gb, shift);
273 /* modulo decoding */
274 if (!s->h263_long_vectors) {
275 val = sign_extend(val, 5 + f_code);
277 /* horrible h263 long vector mode */
278 if (pred < -31 && val < -63)
280 if (pred > 32 && val > 63)
288 /* Decode RVLC of H.263+ UMV */
289 static int h263p_decode_umotion(MpegEncContext * s, int pred)
293 if (get_bits1(&s->gb)) /* Motion difference = 0 */
296 code = 2 + get_bits1(&s->gb);
298 while (get_bits1(&s->gb))
301 code += get_bits1(&s->gb);
306 code = (sign) ? (pred - code) : (pred + code);
307 ff_tlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
313 * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :)
315 static void preview_obmc(MpegEncContext *s){
316 GetBitContext gb= s->gb;
318 int cbpc, i, pred_x, pred_y, mx, my;
320 const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
321 const int stride= s->b8_stride*2;
324 s->block_index[i]+= 2;
326 s->block_index[i]+= 1;
329 av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
332 if (get_bits1(&s->gb)) {
334 mot_val = s->current_picture.motion_val[0][s->block_index[0]];
335 mot_val[0 ]= mot_val[2 ]=
336 mot_val[0+stride]= mot_val[2+stride]= 0;
337 mot_val[1 ]= mot_val[3 ]=
338 mot_val[1+stride]= mot_val[3+stride]= 0;
340 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
343 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
347 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
349 get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
351 if(s->modified_quant){
352 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
353 else skip_bits(&s->gb, 5);
355 skip_bits(&s->gb, 2);
358 if ((cbpc & 16) == 0) {
359 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
360 /* 16x16 motion prediction */
361 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
363 mx = h263p_decode_umotion(s, pred_x);
365 mx = ff_h263_decode_motion(s, pred_x, 1);
368 my = h263p_decode_umotion(s, pred_y);
370 my = ff_h263_decode_motion(s, pred_y, 1);
372 mot_val[0 ]= mot_val[2 ]=
373 mot_val[0+stride]= mot_val[2+stride]= mx;
374 mot_val[1 ]= mot_val[3 ]=
375 mot_val[1+stride]= mot_val[3+stride]= my;
377 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
379 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
381 mx = h263p_decode_umotion(s, pred_x);
383 mx = ff_h263_decode_motion(s, pred_x, 1);
386 my = h263p_decode_umotion(s, pred_y);
388 my = ff_h263_decode_motion(s, pred_y, 1);
389 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
390 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
399 s->block_index[i]-= 2;
401 s->block_index[i]-= 1;
407 static void h263_decode_dquant(MpegEncContext *s){
408 static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
410 if(s->modified_quant){
411 if(get_bits1(&s->gb))
412 s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
414 s->qscale= get_bits(&s->gb, 5);
416 s->qscale += quant_tab[get_bits(&s->gb, 2)];
417 ff_set_qscale(s, s->qscale);
420 static int h263_decode_block(MpegEncContext * s, int16_t * block,
423 int level, i, j, run;
424 RLTable *rl = &ff_h263_rl_inter;
425 const uint8_t *scan_table;
426 GetBitContext gb= s->gb;
428 scan_table = s->intra_scantable.permutated;
429 if (s->h263_aic && s->mb_intra) {
430 rl = &ff_rl_intra_aic;
434 scan_table = s->intra_v_scantable.permutated; /* left */
436 scan_table = s->intra_h_scantable.permutated; /* top */
438 } else if (s->mb_intra) {
440 if (CONFIG_RV10_DECODER && s->codec_id == AV_CODEC_ID_RV10) {
441 if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
443 component = (n <= 3 ? 0 : n - 4 + 1);
444 level = s->last_dc[component];
445 if (s->rv10_first_dc_coded[component]) {
446 diff = ff_rv_decode_dc(s, n);
450 level = level & 0xff; /* handle wrap round */
451 s->last_dc[component] = level;
453 s->rv10_first_dc_coded[component] = 1;
456 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->avctx->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 OPEN_READER(re, &s->gb);
484 i--; // offset by -1 to allow direct indexing of scan_table
486 UPDATE_CACHE(re, &s->gb);
487 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
490 CLOSE_READER(re, &s->gb);
491 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
495 if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
496 int is11 = SHOW_UBITS(re, &s->gb, 1);
497 SKIP_CACHE(re, &s->gb, 1);
498 run = SHOW_UBITS(re, &s->gb, 7) + 1;
500 SKIP_COUNTER(re, &s->gb, 1 + 7);
501 UPDATE_CACHE(re, &s->gb);
502 level = SHOW_SBITS(re, &s->gb, 11);
503 SKIP_COUNTER(re, &s->gb, 11);
505 SKIP_CACHE(re, &s->gb, 7);
506 level = SHOW_SBITS(re, &s->gb, 7);
507 SKIP_COUNTER(re, &s->gb, 1 + 7 + 7);
510 run = SHOW_UBITS(re, &s->gb, 7) + 1;
511 SKIP_CACHE(re, &s->gb, 7);
512 level = (int8_t)SHOW_UBITS(re, &s->gb, 8);
513 SKIP_COUNTER(re, &s->gb, 7 + 8);
515 UPDATE_CACHE(re, &s->gb);
516 if (s->codec_id == AV_CODEC_ID_RV10) {
517 /* XXX: should patch encoder too */
518 level = SHOW_SBITS(re, &s->gb, 12);
519 SKIP_COUNTER(re, &s->gb, 12);
521 level = SHOW_UBITS(re, &s->gb, 5);
522 SKIP_CACHE(re, &s->gb, 5);
523 level |= SHOW_SBITS(re, &s->gb, 6)<<5;
524 SKIP_COUNTER(re, &s->gb, 5 + 6);
529 if (SHOW_UBITS(re, &s->gb, 1))
531 SKIP_COUNTER(re, &s->gb, 1);
535 CLOSE_READER(re, &s->gb);
536 // redo update without last flag, revert -1 offset
537 i = i - run + ((run-1)&63) + 1;
539 // only last marker, no overrun
540 block[scan_table[i]] = level;
543 if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
544 //Looks like a hack but no, it's the way it is supposed to work ...
545 rl = &ff_rl_intra_aic;
548 s->bdsp.clear_block(block);
551 av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
559 if (s->mb_intra && s->h263_aic) {
560 ff_h263_pred_acdc(s, block, n);
563 s->block_last_index[n] = i;
567 static int h263_skip_b_part(MpegEncContext *s, int cbp)
569 LOCAL_ALIGNED_16(int16_t, dblock, [64]);
573 /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
574 * but real value should be restored in order to be used later (in OBMC condition)
577 memcpy(bli, s->block_last_index, sizeof(bli));
579 for (i = 0; i < 6; i++) {
580 if (h263_decode_block(s, dblock, i, cbp&32) < 0)
585 memcpy(s->block_last_index, bli, sizeof(bli));
589 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
593 if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
595 if (pb_frame == 2 && c)
597 } else { // h.263 Annex M improved PB-frame
598 mv = get_unary(gb, 0, 4) + 1;
603 *cbpb = get_bits(gb, 6);
607 int ff_h263_decode_mb(MpegEncContext *s,
608 int16_t block[6][64])
610 int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
612 const int xy= s->mb_x + s->mb_y * s->mb_stride;
613 int cbpb = 0, pb_mv_count = 0;
615 av_assert2(!s->h263_pred);
617 if (s->pict_type == AV_PICTURE_TYPE_P) {
619 if (get_bits1(&s->gb)) {
623 s->block_last_index[i] = -1;
624 s->mv_dir = MV_DIR_FORWARD;
625 s->mv_type = MV_TYPE_16X16;
626 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
629 s->mb_skipped = !(s->obmc | s->loop_filter);
632 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
634 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
639 s->bdsp.clear_blocks(s->block[0]);
642 s->mb_intra = ((cbpc & 4) != 0);
643 if (s->mb_intra) goto intra;
645 if(s->pb_frame && get_bits1(&s->gb))
646 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
647 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
649 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
652 cbp = (cbpc & 3) | (cbpy << 2);
654 h263_decode_dquant(s);
657 s->mv_dir = MV_DIR_FORWARD;
658 if ((cbpc & 16) == 0) {
659 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
660 /* 16x16 motion prediction */
661 s->mv_type = MV_TYPE_16X16;
662 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
664 mx = h263p_decode_umotion(s, pred_x);
666 mx = ff_h263_decode_motion(s, pred_x, 1);
672 my = h263p_decode_umotion(s, pred_y);
674 my = ff_h263_decode_motion(s, pred_y, 1);
681 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
682 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
684 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
685 s->mv_type = MV_TYPE_8X8;
687 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
689 mx = h263p_decode_umotion(s, pred_x);
691 mx = ff_h263_decode_motion(s, pred_x, 1);
696 my = h263p_decode_umotion(s, pred_y);
698 my = ff_h263_decode_motion(s, pred_y, 1);
703 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
704 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
709 } else if(s->pict_type==AV_PICTURE_TYPE_B) {
711 const int stride= s->b8_stride;
712 int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
713 int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
714 // const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
717 mot_val0[0 ]= mot_val0[2 ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
718 mot_val0[1 ]= mot_val0[3 ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
719 mot_val1[0 ]= mot_val1[2 ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
720 mot_val1[1 ]= mot_val1[3 ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
723 mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
725 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
729 mb_type= h263_mb_type_b_map[ mb_type ];
732 s->mb_intra = IS_INTRA(mb_type);
733 if(HAS_CBP(mb_type)){
734 s->bdsp.clear_blocks(s->block[0]);
735 cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
737 dquant = IS_QUANT(mb_type);
741 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
744 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
748 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
751 cbp = (cbpc & 3) | (cbpy << 2);
755 av_assert2(!s->mb_intra);
757 if(IS_QUANT(mb_type)){
758 h263_decode_dquant(s);
761 if(IS_DIRECT(mb_type)){
762 s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
763 mb_type |= ff_mpeg4_set_direct_mv(s, 0, 0);
766 s->mv_type= MV_TYPE_16X16;
769 if(USES_LIST(mb_type, 0)){
770 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &mx, &my);
771 s->mv_dir = MV_DIR_FORWARD;
773 mx = ff_h263_decode_motion(s, mx, 1);
774 my = ff_h263_decode_motion(s, my, 1);
778 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
779 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
782 if(USES_LIST(mb_type, 1)){
783 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &mx, &my);
784 s->mv_dir |= MV_DIR_BACKWARD;
786 mx = ff_h263_decode_motion(s, mx, 1);
787 my = ff_h263_decode_motion(s, my, 1);
791 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
792 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
796 s->current_picture.mb_type[xy] = mb_type;
797 } else { /* I-Frame */
799 cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
801 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
806 s->bdsp.clear_blocks(s->block[0]);
811 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
813 s->ac_pred = get_bits1(&s->gb);
815 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
817 s->h263_aic_dir = get_bits1(&s->gb);
822 if(s->pb_frame && get_bits1(&s->gb))
823 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
824 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
826 av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
829 cbp = (cbpc & 3) | (cbpy << 2);
831 h263_decode_dquant(s);
834 pb_mv_count += !!s->pb_frame;
837 while(pb_mv_count--){
838 ff_h263_decode_motion(s, 0, 1);
839 ff_h263_decode_motion(s, 0, 1);
842 /* decode each block */
843 for (i = 0; i < 6; i++) {
844 if (h263_decode_block(s, block[i], i, cbp&32) < 0)
849 if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
851 if(s->obmc && !s->mb_intra){
852 if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
857 /* per-MB end of slice check */
859 int v= show_bits(&s->gb, 16);
861 if (get_bits_left(&s->gb) < 16) {
862 v >>= 16 - get_bits_left(&s->gb);
872 /* most is hardcoded. should extend to handle all h263 streams */
873 int ff_h263_decode_picture_header(MpegEncContext *s)
875 int format, width, height, i;
878 align_get_bits(&s->gb);
880 if (show_bits(&s->gb, 2) == 2 && s->avctx->frame_number == 0) {
881 av_log(s->avctx, AV_LOG_WARNING, "Header looks like RTP instead of H.263\n");
884 startcode= get_bits(&s->gb, 22-8);
886 for(i= get_bits_left(&s->gb); i>24; i-=8) {
887 startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
889 if(startcode == 0x20)
893 if (startcode != 0x20) {
894 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
897 /* temporal reference */
898 i = get_bits(&s->gb, 8); /* picture timestamp */
899 if( (s->picture_number&~0xFF)+i < s->picture_number)
901 s->picture_number= (s->picture_number&~0xFF) + i;
903 /* PTYPE starts here */
904 if (check_marker(&s->gb, "in PTYPE") != 1) {
907 if (get_bits1(&s->gb) != 0) {
908 av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
909 return -1; /* h263 id */
911 skip_bits1(&s->gb); /* split screen off */
912 skip_bits1(&s->gb); /* camera off */
913 skip_bits1(&s->gb); /* freeze picture release off */
915 format = get_bits(&s->gb, 3);
920 7 extended PTYPE (PLUSPTYPE)
923 if (format != 7 && format != 6) {
926 width = ff_h263_format[format][0];
927 height = ff_h263_format[format][1];
931 s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
933 s->h263_long_vectors = get_bits1(&s->gb);
935 if (get_bits1(&s->gb) != 0) {
936 av_log(s->avctx, AV_LOG_ERROR, "H263 SAC not supported\n");
937 return -1; /* SAC: off */
939 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
940 s->unrestricted_mv = s->h263_long_vectors || s->obmc;
942 s->pb_frame = get_bits1(&s->gb);
943 s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
944 skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
948 s->avctx->sample_aspect_ratio= (AVRational){12,11};
949 s->avctx->framerate = (AVRational){ 30000, 1001 };
955 ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
957 /* ufep other than 0 and 1 are reserved */
960 format = get_bits(&s->gb, 3);
961 ff_dlog(s->avctx, "ufep=1, format: %d\n", format);
962 s->custom_pcf= get_bits1(&s->gb);
963 s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
964 if (get_bits1(&s->gb) != 0) {
965 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
967 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
968 s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
969 s->loop_filter= get_bits1(&s->gb);
970 s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter;
974 s->h263_slice_structured= get_bits1(&s->gb);
975 if (get_bits1(&s->gb) != 0) {
976 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
978 if (get_bits1(&s->gb) != 0) {
979 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
981 s->alt_inter_vlc= get_bits1(&s->gb);
982 s->modified_quant= get_bits1(&s->gb);
983 if(s->modified_quant)
984 s->chroma_qscale_table= ff_h263_chroma_qscale_table;
986 skip_bits(&s->gb, 1); /* Prevent start code emulation */
988 skip_bits(&s->gb, 3); /* Reserved */
989 } else if (ufep != 0) {
990 av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
995 s->pict_type = get_bits(&s->gb, 3);
996 switch(s->pict_type){
997 case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
998 case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
999 case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
1000 case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
1001 case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
1005 skip_bits(&s->gb, 2);
1006 s->no_rounding = get_bits1(&s->gb);
1007 skip_bits(&s->gb, 4);
1009 /* Get the picture dimensions */
1012 /* Custom Picture Format (CPFMT) */
1013 s->aspect_ratio_info = get_bits(&s->gb, 4);
1014 ff_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
1019 3 - 10:11 (525-type 4:3)
1020 4 - 16:11 (CIF 16:9)
1021 5 - 40:33 (525-type 16:9)
1024 width = (get_bits(&s->gb, 9) + 1) * 4;
1025 check_marker(&s->gb, "in dimensions");
1026 height = get_bits(&s->gb, 9) * 4;
1027 ff_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1028 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1029 /* aspected dimensions */
1030 s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1031 s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1033 s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1036 width = ff_h263_format[format][0];
1037 height = ff_h263_format[format][1];
1038 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1040 s->avctx->sample_aspect_ratio.den <<= s->ehc_mode;
1041 if ((width == 0) || (height == 0))
1048 s->avctx->framerate.num = 1800000;
1049 s->avctx->framerate.den = 1000 + get_bits1(&s->gb);
1050 s->avctx->framerate.den *= get_bits(&s->gb, 7);
1051 if(s->avctx->framerate.den == 0){
1052 av_log(s, AV_LOG_ERROR, "zero framerate\n");
1055 gcd= av_gcd(s->avctx->framerate.den, s->avctx->framerate.num);
1056 s->avctx->framerate.den /= gcd;
1057 s->avctx->framerate.num /= gcd;
1059 s->avctx->framerate = (AVRational){ 30000, 1001 };
1064 skip_bits(&s->gb, 2); //extended Temporal reference
1069 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
1072 if(s->h263_slice_structured){
1073 if (get_bits1(&s->gb) != 0) {
1074 av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
1076 if (get_bits1(&s->gb) != 0) {
1077 av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1082 s->qscale = get_bits(&s->gb, 5);
1085 if (s->width == 0 || s->height == 0) {
1086 av_log(s->avctx, AV_LOG_ERROR, "dimensions 0\n");
1089 s->mb_width = (s->width + 15) / 16;
1090 s->mb_height = (s->height + 15) / 16;
1091 s->mb_num = s->mb_width * s->mb_height;
1094 skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1096 skip_bits(&s->gb, 2); //extended Temporal reference
1097 skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1100 if (s->pict_type!=AV_PICTURE_TYPE_B) {
1101 s->time = s->picture_number;
1102 s->pp_time = s->time - s->last_non_b_time;
1103 s->last_non_b_time = s->time;
1105 s->time = s->picture_number;
1106 s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
1107 if (s->pp_time <=s->pb_time ||
1108 s->pp_time <= s->pp_time - s->pb_time ||
1113 ff_mpeg4_init_direct_mv(s);
1117 if (skip_1stop_8data_bits(&s->gb) < 0)
1118 return AVERROR_INVALIDDATA;
1120 if(s->h263_slice_structured){
1121 if (check_marker(&s->gb, "SEPB1") != 1) {
1125 ff_h263_decode_mba(s);
1127 if (check_marker(&s->gb, "SEPB2") != 1) {
1134 s->y_dc_scale_table=
1135 s->c_dc_scale_table= ff_aic_dc_scale_table;
1137 s->y_dc_scale_table=
1138 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1141 ff_h263_show_pict_info(s);
1142 if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
1144 for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1145 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1146 for(i=0; i<13; i++){
1148 int v= get_bits(&s->gb, 8);
1149 v |= get_sbits(&s->gb, 8)<<8;
1150 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1152 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1154 for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));