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"
46 // The defines below define the number of bits that are read at once for
47 // reading vlc values. Changing these may improve speed and data cache needs
48 // be aware though that decreasing them may need the number of stages that is
49 // passed to get_vlc* to be increased.
51 #define H263_MBTYPE_B_VLC_BITS 6
52 #define CBPC_B_VLC_BITS 3
54 static const int h263_mb_type_b_map[15]= {
55 MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
56 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
57 MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
58 MB_TYPE_L0 | MB_TYPE_16x16,
59 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_16x16,
60 MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
61 MB_TYPE_L1 | MB_TYPE_16x16,
62 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_16x16,
63 MB_TYPE_L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
64 MB_TYPE_L0L1 | MB_TYPE_16x16,
65 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_16x16,
66 MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
68 MB_TYPE_INTRA4x4 | MB_TYPE_CBP,
69 MB_TYPE_INTRA4x4 | MB_TYPE_CBP | MB_TYPE_QUANT,
72 void ff_h263_show_pict_info(MpegEncContext *s){
73 if(s->avctx->debug&FF_DEBUG_PICT_INFO){
74 av_log(s->avctx, AV_LOG_DEBUG, "qp:%d %c size:%d rnd:%d%s%s%s%s%s%s%s%s%s %d/%d\n",
75 s->qscale, av_get_picture_type_char(s->pict_type),
76 s->gb.size_in_bits, 1-s->no_rounding,
78 s->umvplus ? " UMV" : "",
79 s->h263_long_vectors ? " LONG" : "",
80 s->h263_plus ? " +" : "",
81 s->h263_aic ? " AIC" : "",
82 s->alt_inter_vlc ? " AIV" : "",
83 s->modified_quant ? " MQ" : "",
84 s->loop_filter ? " LOOP" : "",
85 s->h263_slice_structured ? " SS" : "",
86 s->avctx->framerate.num, s->avctx->framerate.den
91 /***********************************************/
94 VLC ff_h263_intra_MCBPC_vlc;
95 VLC ff_h263_inter_MCBPC_vlc;
98 static VLC h263_mbtype_b_vlc;
99 static VLC cbpc_b_vlc;
103 /* XXX: find a better solution to handle static init */
104 av_cold void ff_h263_decode_init_vlc(void)
106 static volatile int done = 0;
109 INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
110 ff_h263_intra_MCBPC_bits, 1, 1,
111 ff_h263_intra_MCBPC_code, 1, 1, 72);
112 INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
113 ff_h263_inter_MCBPC_bits, 1, 1,
114 ff_h263_inter_MCBPC_code, 1, 1, 198);
115 INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
116 &ff_h263_cbpy_tab[0][1], 2, 1,
117 &ff_h263_cbpy_tab[0][0], 2, 1, 64);
118 INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
119 &ff_mvtab[0][1], 2, 1,
120 &ff_mvtab[0][0], 2, 1, 538);
121 ff_init_rl(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
122 ff_init_rl(&ff_rl_intra_aic, ff_h263_static_rl_table_store[1]);
123 INIT_VLC_RL(ff_h263_rl_inter, 554);
124 INIT_VLC_RL(ff_rl_intra_aic, 554);
125 INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
126 &ff_h263_mbtype_b_tab[0][1], 2, 1,
127 &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
128 INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
129 &ff_cbpc_b_tab[0][1], 2, 1,
130 &ff_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 * Decode 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, 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(check_marker(&s->gb, "before MBA")==0)
177 ff_h263_decode_mba(s);
180 if(check_marker(&s->gb, "after MBA")==0)
183 s->qscale = get_bits(&s->gb, 5); /* SQUANT */
184 if(check_marker(&s->gb, "after SQUANT")==0)
186 skip_bits(&s->gb, 2); /* GFID */
188 gob_number = get_bits(&s->gb, 5); /* GN */
190 s->mb_y= s->gob_index* gob_number;
191 skip_bits(&s->gb, 2); /* GFID */
192 s->qscale = get_bits(&s->gb, 5); /* GQUANT */
195 if(s->mb_y >= s->mb_height)
205 * Decode the group of blocks / video packet header.
206 * @return bit position of the resync_marker, or <0 if none was found
208 int ff_h263_resync(MpegEncContext *s){
211 if(s->codec_id==AV_CODEC_ID_MPEG4){
213 align_get_bits(&s->gb);
216 if(show_bits(&s->gb, 16)==0){
217 pos= get_bits_count(&s->gb);
218 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
219 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
221 ret= h263_decode_gob_header(s);
225 //OK, it's not where it is supposed to be ...
226 s->gb= s->last_resync_gb;
227 align_get_bits(&s->gb);
228 left= get_bits_left(&s->gb);
230 for(;left>16+1+5+5; left-=8){
231 if(show_bits(&s->gb, 16)==0){
232 GetBitContext bak= s->gb;
234 pos= get_bits_count(&s->gb);
235 if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
236 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
238 ret= h263_decode_gob_header(s);
244 skip_bits(&s->gb, 8);
250 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
252 int code, val, sign, shift;
253 code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
260 sign = get_bits1(&s->gb);
264 val = (val - 1) << shift;
265 val |= get_bits(&s->gb, shift);
272 /* modulo decoding */
273 if (!s->h263_long_vectors) {
274 val = sign_extend(val, 5 + f_code);
276 /* horrible h263 long vector mode */
277 if (pred < -31 && val < -63)
279 if (pred > 32 && val > 63)
287 /* Decode RVLC of H.263+ UMV */
288 static int h263p_decode_umotion(MpegEncContext * s, int pred)
292 if (get_bits1(&s->gb)) /* Motion difference = 0 */
295 code = 2 + get_bits1(&s->gb);
297 while (get_bits1(&s->gb))
300 code += get_bits1(&s->gb);
305 code = (sign) ? (pred - code) : (pred + code);
306 ff_dlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
312 * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :)
314 static void preview_obmc(MpegEncContext *s){
315 GetBitContext gb= s->gb;
317 int cbpc, i, pred_x, pred_y, mx, my;
319 const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
320 const int stride= s->b8_stride*2;
323 s->block_index[i]+= 2;
325 s->block_index[i]+= 1;
328 av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
331 if (get_bits1(&s->gb)) {
333 mot_val = s->current_picture.motion_val[0][s->block_index[0]];
334 mot_val[0 ]= mot_val[2 ]=
335 mot_val[0+stride]= mot_val[2+stride]= 0;
336 mot_val[1 ]= mot_val[3 ]=
337 mot_val[1+stride]= mot_val[3+stride]= 0;
339 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
342 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
346 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
348 get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
350 if(s->modified_quant){
351 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
352 else skip_bits(&s->gb, 5);
354 skip_bits(&s->gb, 2);
357 if ((cbpc & 16) == 0) {
358 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
359 /* 16x16 motion prediction */
360 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
362 mx = h263p_decode_umotion(s, pred_x);
364 mx = ff_h263_decode_motion(s, pred_x, 1);
367 my = h263p_decode_umotion(s, pred_y);
369 my = ff_h263_decode_motion(s, pred_y, 1);
371 mot_val[0 ]= mot_val[2 ]=
372 mot_val[0+stride]= mot_val[2+stride]= mx;
373 mot_val[1 ]= mot_val[3 ]=
374 mot_val[1+stride]= mot_val[3+stride]= my;
376 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
378 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
380 mx = h263p_decode_umotion(s, pred_x);
382 mx = ff_h263_decode_motion(s, pred_x, 1);
385 my = h263p_decode_umotion(s, pred_y);
387 my = ff_h263_decode_motion(s, pred_y, 1);
388 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
389 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
398 s->block_index[i]-= 2;
400 s->block_index[i]-= 1;
406 static void h263_decode_dquant(MpegEncContext *s){
407 static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
409 if(s->modified_quant){
410 if(get_bits1(&s->gb))
411 s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
413 s->qscale= get_bits(&s->gb, 5);
415 s->qscale += quant_tab[get_bits(&s->gb, 2)];
416 ff_set_qscale(s, s->qscale);
419 static int h263_decode_block(MpegEncContext * s, int16_t * block,
422 int level, i, j, run;
423 RLTable *rl = &ff_h263_rl_inter;
424 const uint8_t *scan_table;
425 GetBitContext gb= s->gb;
427 scan_table = s->intra_scantable.permutated;
428 if (s->h263_aic && s->mb_intra) {
429 rl = &ff_rl_intra_aic;
433 scan_table = s->intra_v_scantable.permutated; /* left */
435 scan_table = s->intra_h_scantable.permutated; /* top */
437 } else if (s->mb_intra) {
439 if (CONFIG_RV10_DECODER && s->codec_id == AV_CODEC_ID_RV10) {
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);
460 level = get_bits(&s->gb, 8);
461 if((level&0x7F) == 0){
462 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
463 if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
475 if (s->mb_intra && s->h263_aic)
477 s->block_last_index[n] = i - 1;
482 OPEN_READER(re, &s->gb);
483 i--; // offset by -1 to allow direct indexing of scan_table
485 UPDATE_CACHE(re, &s->gb);
486 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
489 CLOSE_READER(re, &s->gb);
490 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
494 if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
495 int is11 = SHOW_UBITS(re, &s->gb, 1);
496 SKIP_CACHE(re, &s->gb, 1);
497 run = SHOW_UBITS(re, &s->gb, 7) + 1;
499 SKIP_COUNTER(re, &s->gb, 1 + 7);
500 UPDATE_CACHE(re, &s->gb);
501 level = SHOW_SBITS(re, &s->gb, 11);
502 SKIP_COUNTER(re, &s->gb, 11);
504 SKIP_CACHE(re, &s->gb, 7);
505 level = SHOW_SBITS(re, &s->gb, 7);
506 SKIP_COUNTER(re, &s->gb, 1 + 7 + 7);
509 run = SHOW_UBITS(re, &s->gb, 7) + 1;
510 SKIP_CACHE(re, &s->gb, 7);
511 level = (int8_t)SHOW_UBITS(re, &s->gb, 8);
512 SKIP_COUNTER(re, &s->gb, 7 + 8);
514 UPDATE_CACHE(re, &s->gb);
515 if (s->codec_id == AV_CODEC_ID_RV10) {
516 /* XXX: should patch encoder too */
517 level = SHOW_SBITS(re, &s->gb, 12);
518 SKIP_COUNTER(re, &s->gb, 12);
520 level = SHOW_UBITS(re, &s->gb, 5);
521 SKIP_CACHE(re, &s->gb, 5);
522 level |= SHOW_SBITS(re, &s->gb, 6)<<5;
523 SKIP_COUNTER(re, &s->gb, 5 + 6);
528 if (SHOW_UBITS(re, &s->gb, 1))
530 SKIP_COUNTER(re, &s->gb, 1);
534 CLOSE_READER(re, &s->gb);
535 // redo update without last flag, revert -1 offset
536 i = i - run + ((run-1)&63) + 1;
538 // only last marker, no overrun
539 block[scan_table[i]] = level;
542 if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
543 //Looks like a hack but no, it's the way it is supposed to work ...
544 rl = &ff_rl_intra_aic;
547 s->bdsp.clear_block(block);
550 av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
558 if (s->mb_intra && s->h263_aic) {
559 ff_h263_pred_acdc(s, block, n);
562 s->block_last_index[n] = i;
566 static int h263_skip_b_part(MpegEncContext *s, int cbp)
568 LOCAL_ALIGNED_16(int16_t, dblock, [64]);
572 /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
573 * but real value should be restored in order to be used later (in OBMC condition)
576 memcpy(bli, s->block_last_index, sizeof(bli));
578 for (i = 0; i < 6; i++) {
579 if (h263_decode_block(s, dblock, i, cbp&32) < 0)
584 memcpy(s->block_last_index, bli, sizeof(bli));
588 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
592 if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
594 if (pb_frame == 2 && c)
596 } else { // h.263 Annex M improved PB-frame
597 mv = get_unary(gb, 0, 4) + 1;
602 *cbpb = get_bits(gb, 6);
606 int ff_h263_decode_mb(MpegEncContext *s,
607 int16_t block[6][64])
609 int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
611 const int xy= s->mb_x + s->mb_y * s->mb_stride;
612 int cbpb = 0, pb_mv_count = 0;
614 av_assert2(!s->h263_pred);
616 if (s->pict_type == AV_PICTURE_TYPE_P) {
618 if (get_bits1(&s->gb)) {
622 s->block_last_index[i] = -1;
623 s->mv_dir = MV_DIR_FORWARD;
624 s->mv_type = MV_TYPE_16X16;
625 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
628 s->mb_skipped = !(s->obmc | s->loop_filter);
631 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
633 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
638 s->bdsp.clear_blocks(s->block[0]);
641 s->mb_intra = ((cbpc & 4) != 0);
642 if (s->mb_intra) goto intra;
644 if(s->pb_frame && get_bits1(&s->gb))
645 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
646 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
648 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
651 cbp = (cbpc & 3) | (cbpy << 2);
653 h263_decode_dquant(s);
656 s->mv_dir = MV_DIR_FORWARD;
657 if ((cbpc & 16) == 0) {
658 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
659 /* 16x16 motion prediction */
660 s->mv_type = MV_TYPE_16X16;
661 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
663 mx = h263p_decode_umotion(s, pred_x);
665 mx = ff_h263_decode_motion(s, pred_x, 1);
671 my = h263p_decode_umotion(s, pred_y);
673 my = ff_h263_decode_motion(s, pred_y, 1);
680 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
681 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
683 s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
684 s->mv_type = MV_TYPE_8X8;
686 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
688 mx = h263p_decode_umotion(s, pred_x);
690 mx = ff_h263_decode_motion(s, pred_x, 1);
695 my = h263p_decode_umotion(s, pred_y);
697 my = ff_h263_decode_motion(s, pred_y, 1);
702 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
703 skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
708 } else if(s->pict_type==AV_PICTURE_TYPE_B) {
710 const int stride= s->b8_stride;
711 int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
712 int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
713 // const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
716 mot_val0[0 ]= mot_val0[2 ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
717 mot_val0[1 ]= mot_val0[3 ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
718 mot_val1[0 ]= mot_val1[2 ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
719 mot_val1[1 ]= mot_val1[3 ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
722 mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
724 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
728 mb_type= h263_mb_type_b_map[ mb_type ];
731 s->mb_intra = IS_INTRA(mb_type);
732 if(HAS_CBP(mb_type)){
733 s->bdsp.clear_blocks(s->block[0]);
734 cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
736 dquant = IS_QUANT(mb_type);
740 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
743 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
747 if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
750 cbp = (cbpc & 3) | (cbpy << 2);
754 av_assert2(!s->mb_intra);
756 if(IS_QUANT(mb_type)){
757 h263_decode_dquant(s);
760 if(IS_DIRECT(mb_type)){
761 s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
762 mb_type |= ff_mpeg4_set_direct_mv(s, 0, 0);
765 s->mv_type= MV_TYPE_16X16;
768 if(USES_LIST(mb_type, 0)){
769 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &mx, &my);
770 s->mv_dir = MV_DIR_FORWARD;
772 mx = ff_h263_decode_motion(s, mx, 1);
773 my = ff_h263_decode_motion(s, my, 1);
777 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
778 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
781 if(USES_LIST(mb_type, 1)){
782 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &mx, &my);
783 s->mv_dir |= MV_DIR_BACKWARD;
785 mx = ff_h263_decode_motion(s, mx, 1);
786 my = ff_h263_decode_motion(s, my, 1);
790 mot_val[0 ]= mot_val[2 ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
791 mot_val[1 ]= mot_val[3 ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
795 s->current_picture.mb_type[xy] = mb_type;
796 } else { /* I-Frame */
798 cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
800 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
805 s->bdsp.clear_blocks(s->block[0]);
810 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
812 s->ac_pred = get_bits1(&s->gb);
814 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
816 s->h263_aic_dir = get_bits1(&s->gb);
821 if(s->pb_frame && get_bits1(&s->gb))
822 pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
823 cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
825 av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
828 cbp = (cbpc & 3) | (cbpy << 2);
830 h263_decode_dquant(s);
833 pb_mv_count += !!s->pb_frame;
836 while(pb_mv_count--){
837 ff_h263_decode_motion(s, 0, 1);
838 ff_h263_decode_motion(s, 0, 1);
841 /* decode each block */
842 for (i = 0; i < 6; i++) {
843 if (h263_decode_block(s, block[i], i, cbp&32) < 0)
848 if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
850 if(s->obmc && !s->mb_intra){
851 if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
856 /* per-MB end of slice check */
858 int v= show_bits(&s->gb, 16);
860 if (get_bits_left(&s->gb) < 16) {
861 v >>= 16 - get_bits_left(&s->gb);
871 /* most is hardcoded. should extend to handle all h263 streams */
872 int ff_h263_decode_picture_header(MpegEncContext *s)
874 int format, width, height, i;
877 align_get_bits(&s->gb);
879 if (show_bits(&s->gb, 2) == 2 && s->avctx->frame_number == 0) {
880 av_log(s->avctx, AV_LOG_WARNING, "Header looks like RTP instead of H.263\n");
883 startcode= get_bits(&s->gb, 22-8);
885 for(i= get_bits_left(&s->gb); i>24; i-=8) {
886 startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
888 if(startcode == 0x20)
892 if (startcode != 0x20) {
893 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
896 /* temporal reference */
897 i = get_bits(&s->gb, 8); /* picture timestamp */
898 if( (s->picture_number&~0xFF)+i < s->picture_number)
900 s->picture_number= (s->picture_number&~0xFF) + i;
902 /* PTYPE starts here */
903 if (check_marker(&s->gb, "in PTYPE") != 1) {
906 if (get_bits1(&s->gb) != 0) {
907 av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
908 return -1; /* h263 id */
910 skip_bits1(&s->gb); /* split screen off */
911 skip_bits1(&s->gb); /* camera off */
912 skip_bits1(&s->gb); /* freeze picture release off */
914 format = get_bits(&s->gb, 3);
919 7 extended PTYPE (PLUSPTYPE)
922 if (format != 7 && format != 6) {
925 width = ff_h263_format[format][0];
926 height = ff_h263_format[format][1];
930 s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
932 s->h263_long_vectors = get_bits1(&s->gb);
934 if (get_bits1(&s->gb) != 0) {
935 av_log(s->avctx, AV_LOG_ERROR, "H263 SAC not supported\n");
936 return -1; /* SAC: off */
938 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
939 s->unrestricted_mv = s->h263_long_vectors || s->obmc;
941 s->pb_frame = get_bits1(&s->gb);
942 s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
943 skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
947 s->avctx->sample_aspect_ratio= (AVRational){12,11};
948 s->avctx->framerate = (AVRational){ 30000, 1001 };
954 ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
956 /* ufep other than 0 and 1 are reserved */
959 format = get_bits(&s->gb, 3);
960 ff_dlog(s->avctx, "ufep=1, format: %d\n", format);
961 s->custom_pcf= get_bits1(&s->gb);
962 s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
963 if (get_bits1(&s->gb) != 0) {
964 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
966 s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
967 s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
968 s->loop_filter= get_bits1(&s->gb);
969 s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter;
973 s->h263_slice_structured= get_bits1(&s->gb);
974 if (get_bits1(&s->gb) != 0) {
975 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
977 if (get_bits1(&s->gb) != 0) {
978 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
980 s->alt_inter_vlc= get_bits1(&s->gb);
981 s->modified_quant= get_bits1(&s->gb);
982 if(s->modified_quant)
983 s->chroma_qscale_table= ff_h263_chroma_qscale_table;
985 skip_bits(&s->gb, 1); /* Prevent start code emulation */
987 skip_bits(&s->gb, 3); /* Reserved */
988 } else if (ufep != 0) {
989 av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
994 s->pict_type = get_bits(&s->gb, 3);
995 switch(s->pict_type){
996 case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
997 case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
998 case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
999 case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
1000 case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
1004 skip_bits(&s->gb, 2);
1005 s->no_rounding = get_bits1(&s->gb);
1006 skip_bits(&s->gb, 4);
1008 /* Get the picture dimensions */
1011 /* Custom Picture Format (CPFMT) */
1012 s->aspect_ratio_info = get_bits(&s->gb, 4);
1013 ff_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
1018 3 - 10:11 (525-type 4:3)
1019 4 - 16:11 (CIF 16:9)
1020 5 - 40:33 (525-type 16:9)
1023 width = (get_bits(&s->gb, 9) + 1) * 4;
1024 check_marker(&s->gb, "in dimensions");
1025 height = get_bits(&s->gb, 9) * 4;
1026 ff_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1027 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1028 /* aspected dimensions */
1029 s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1030 s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1032 s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1035 width = ff_h263_format[format][0];
1036 height = ff_h263_format[format][1];
1037 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1039 s->avctx->sample_aspect_ratio.den <<= s->ehc_mode;
1040 if ((width == 0) || (height == 0))
1047 s->avctx->framerate.num = 1800000;
1048 s->avctx->framerate.den = 1000 + get_bits1(&s->gb);
1049 s->avctx->framerate.den *= get_bits(&s->gb, 7);
1050 if(s->avctx->framerate.den == 0){
1051 av_log(s, AV_LOG_ERROR, "zero framerate\n");
1054 gcd= av_gcd(s->avctx->framerate.den, s->avctx->framerate.num);
1055 s->avctx->framerate.den /= gcd;
1056 s->avctx->framerate.num /= gcd;
1058 s->avctx->framerate = (AVRational){ 30000, 1001 };
1063 skip_bits(&s->gb, 2); //extended Temporal reference
1068 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
1071 if(s->h263_slice_structured){
1072 if (get_bits1(&s->gb) != 0) {
1073 av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
1075 if (get_bits1(&s->gb) != 0) {
1076 av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1081 s->qscale = get_bits(&s->gb, 5);
1084 if (s->width == 0 || s->height == 0) {
1085 av_log(s->avctx, AV_LOG_ERROR, "dimensions 0\n");
1088 s->mb_width = (s->width + 15) / 16;
1089 s->mb_height = (s->height + 15) / 16;
1090 s->mb_num = s->mb_width * s->mb_height;
1093 skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1095 skip_bits(&s->gb, 2); //extended Temporal reference
1096 skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1099 if (s->pict_type!=AV_PICTURE_TYPE_B) {
1100 s->time = s->picture_number;
1101 s->pp_time = s->time - s->last_non_b_time;
1102 s->last_non_b_time = s->time;
1104 s->time = s->picture_number;
1105 s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
1106 if (s->pp_time <=s->pb_time ||
1107 s->pp_time <= s->pp_time - s->pb_time ||
1112 ff_mpeg4_init_direct_mv(s);
1116 if (skip_1stop_8data_bits(&s->gb) < 0)
1117 return AVERROR_INVALIDDATA;
1119 if(s->h263_slice_structured){
1120 if (check_marker(&s->gb, "SEPB1") != 1) {
1124 ff_h263_decode_mba(s);
1126 if (check_marker(&s->gb, "SEPB2") != 1) {
1133 s->y_dc_scale_table=
1134 s->c_dc_scale_table= ff_aic_dc_scale_table;
1136 s->y_dc_scale_table=
1137 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1140 ff_h263_show_pict_info(s);
1141 if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
1143 for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1144 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1145 for(i=0; i<13; i++){
1147 int v= get_bits(&s->gb, 8);
1148 v |= get_sbits(&s->gb, 8)<<8;
1149 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1151 av_log(s->avctx, AV_LOG_DEBUG, "\n");
1153 for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));