1/*
2 * ITU H.263 bitstream decoder
3 * Copyright (c) 2000,2001 Fabrice Bellard
4 * H.263+ support.
5 * Copyright (c) 2001 Juan J. Sierralta P
6 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
7 *
8 * This file is part of FFmpeg.
9 *
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.
14 *
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.
19 *
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
23 */
24
25/**
26 * @file
27 * H.263 decoder.
28 */
29
30#define UNCHECKED_BITSTREAM_READER 1
31
32#include "config_components.h"
33
34#include "libavutil/attributes.h"
35#include "libavutil/imgutils.h"
36#include "libavutil/internal.h"
37#include "libavutil/mathematics.h"
38#include "libavutil/mem_internal.h"
39#include "libavutil/thread.h"
40#include "avcodec.h"
41#include "mpegvideo.h"
42#include "h263.h"
43#include "h263data.h"
44#include "h263dec.h"
45#include "mathops.h"
46#include "mpegutils.h"
47#include "unary.h"
48#include "rv10dec.h"
49#include "mpeg4video.h"
50#include "mpegvideodata.h"
51#include "mpegvideodec.h"
52#include "mpeg4videodec.h"
53
54// The defines below define the number of bits that are read at once for
55// reading vlc values. Changing these may improve speed and data cache needs
56// be aware though that decreasing them may need the number of stages that is
57// passed to get_vlc* to be increased.
58#define H263_MBTYPE_B_VLC_BITS 6
59#define CBPC_B_VLC_BITS 3
60
61static const int h263_mb_type_b_map[15]= {
62    MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
63    MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
64    MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
65                      MB_TYPE_L0                                 | MB_TYPE_16x16,
66                      MB_TYPE_L0   | MB_TYPE_CBP                 | MB_TYPE_16x16,
67                      MB_TYPE_L0   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
68                      MB_TYPE_L1                                 | MB_TYPE_16x16,
69                      MB_TYPE_L1   | MB_TYPE_CBP                 | MB_TYPE_16x16,
70                      MB_TYPE_L1   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
71                      MB_TYPE_L0L1                               | MB_TYPE_16x16,
72                      MB_TYPE_L0L1 | MB_TYPE_CBP                 | MB_TYPE_16x16,
73                      MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
74    0, //stuffing
75    MB_TYPE_INTRA4x4                | MB_TYPE_CBP,
76    MB_TYPE_INTRA4x4                | MB_TYPE_CBP | MB_TYPE_QUANT,
77};
78
79void ff_h263_show_pict_info(MpegEncContext *s){
80    if(s->avctx->debug&FF_DEBUG_PICT_INFO){
81    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",
82         s->qscale, av_get_picture_type_char(s->pict_type),
83         s->gb.size_in_bits, 1-s->no_rounding,
84         s->obmc ? " AP" : "",
85         s->umvplus ? " UMV" : "",
86         s->h263_long_vectors ? " LONG" : "",
87         s->h263_plus ? " +" : "",
88         s->h263_aic ? " AIC" : "",
89         s->alt_inter_vlc ? " AIV" : "",
90         s->modified_quant ? " MQ" : "",
91         s->loop_filter ? " LOOP" : "",
92         s->h263_slice_structured ? " SS" : "",
93         s->avctx->framerate.num, s->avctx->framerate.den
94    );
95    }
96}
97
98/***********************************************/
99/* decoding */
100
101VLC ff_h263_intra_MCBPC_vlc;
102VLC ff_h263_inter_MCBPC_vlc;
103VLC ff_h263_cbpy_vlc;
104VLC ff_h263_mv_vlc;
105static VLC h263_mbtype_b_vlc;
106static VLC cbpc_b_vlc;
107
108/* init vlcs */
109
110static av_cold void h263_decode_init_vlc(void)
111{
112    INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
113                    ff_h263_intra_MCBPC_bits, 1, 1,
114                    ff_h263_intra_MCBPC_code, 1, 1, 72);
115    INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
116                    ff_h263_inter_MCBPC_bits, 1, 1,
117                    ff_h263_inter_MCBPC_code, 1, 1, 198);
118    INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
119                    &ff_h263_cbpy_tab[0][1], 2, 1,
120                    &ff_h263_cbpy_tab[0][0], 2, 1, 64);
121    INIT_VLC_STATIC(&ff_h263_mv_vlc, H263_MV_VLC_BITS, 33,
122                    &ff_mvtab[0][1], 2, 1,
123                    &ff_mvtab[0][0], 2, 1, 538);
124    ff_h263_init_rl_inter();
125    INIT_VLC_RL(ff_h263_rl_inter, 554);
126    INIT_FIRST_VLC_RL(ff_rl_intra_aic, 554);
127    INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
128                    &ff_h263_mbtype_b_tab[0][1], 2, 1,
129                    &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
130    INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
131                    &ff_cbpc_b_tab[0][1], 2, 1,
132                    &ff_cbpc_b_tab[0][0], 2, 1, 8);
133}
134
135av_cold void ff_h263_decode_init_vlc(void)
136{
137    static AVOnce init_static_once = AV_ONCE_INIT;
138    ff_thread_once(&init_static_once, h263_decode_init_vlc);
139}
140
141int ff_h263_decode_mba(MpegEncContext *s)
142{
143    int i, mb_pos;
144
145    for (i = 0; i < 6; i++)
146        if (s->mb_num - 1 <= ff_mba_max[i])
147            break;
148    mb_pos  = get_bits(&s->gb, ff_mba_length[i]);
149    s->mb_x = mb_pos % s->mb_width;
150    s->mb_y = mb_pos / s->mb_width;
151
152    return mb_pos;
153}
154
155/**
156 * Decode the group of blocks header or slice header.
157 * @return <0 if an error occurred
158 */
159static int h263_decode_gob_header(MpegEncContext *s)
160{
161    unsigned int val, gob_number;
162    int left;
163
164    /* Check for GOB Start Code */
165    val = show_bits(&s->gb, 16);
166    if(val)
167        return -1;
168
169        /* We have a GBSC probably with GSTUFF */
170    skip_bits(&s->gb, 16); /* Drop the zeros */
171    left= get_bits_left(&s->gb);
172    left = FFMIN(left, 32);
173    //MN: we must check the bits left or we might end in an infinite loop (or segfault)
174    for(;left>13; left--){
175        if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
176    }
177    if(left<=13)
178        return -1;
179
180    if(s->h263_slice_structured){
181        if(check_marker(s->avctx, &s->gb, "before MBA")==0)
182            return -1;
183
184        ff_h263_decode_mba(s);
185
186        if(s->mb_num > 1583)
187            if(check_marker(s->avctx, &s->gb, "after MBA")==0)
188                return -1;
189
190        s->qscale = get_bits(&s->gb, 5); /* SQUANT */
191        if(check_marker(s->avctx, &s->gb, "after SQUANT")==0)
192            return -1;
193        skip_bits(&s->gb, 2); /* GFID */
194    }else{
195        gob_number = get_bits(&s->gb, 5); /* GN */
196        s->mb_x= 0;
197        s->mb_y= s->gob_index* gob_number;
198        skip_bits(&s->gb, 2); /* GFID */
199        s->qscale = get_bits(&s->gb, 5); /* GQUANT */
200    }
201
202    if(s->mb_y >= s->mb_height)
203        return -1;
204
205    if(s->qscale==0)
206        return -1;
207
208    return 0;
209}
210
211/**
212 * Decode the group of blocks / video packet header / slice header (MPEG-4 Studio).
213 * @return bit position of the resync_marker, or <0 if none was found
214 */
215int ff_h263_resync(MpegEncContext *s){
216    int left, pos, ret;
217
218    /* In MPEG-4 studio mode look for a new slice startcode
219     * and decode slice header */
220    if(s->codec_id==AV_CODEC_ID_MPEG4 && s->studio_profile) {
221        align_get_bits(&s->gb);
222
223        while (get_bits_left(&s->gb) >= 32 && show_bits_long(&s->gb, 32) != SLICE_STARTCODE) {
224            get_bits(&s->gb, 8);
225        }
226
227        if (get_bits_left(&s->gb) >= 32 && show_bits_long(&s->gb, 32) == SLICE_STARTCODE)
228            return get_bits_count(&s->gb);
229        else
230            return -1;
231    }
232
233    if(s->codec_id==AV_CODEC_ID_MPEG4){
234        skip_bits1(&s->gb);
235        align_get_bits(&s->gb);
236    }
237
238    if(show_bits(&s->gb, 16)==0){
239        pos= get_bits_count(&s->gb);
240        if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
241            ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
242        else
243            ret= h263_decode_gob_header(s);
244        if(ret>=0)
245            return pos;
246    }
247    //OK, it's not where it is supposed to be ...
248    s->gb= s->last_resync_gb;
249    align_get_bits(&s->gb);
250    left= get_bits_left(&s->gb);
251
252    for(;left>16+1+5+5; left-=8){
253        if(show_bits(&s->gb, 16)==0){
254            GetBitContext bak= s->gb;
255
256            pos= get_bits_count(&s->gb);
257            if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
258                ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
259            else
260                ret= h263_decode_gob_header(s);
261            if(ret>=0)
262                return pos;
263
264            s->gb= bak;
265        }
266        skip_bits(&s->gb, 8);
267    }
268
269    return -1;
270}
271
272int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
273{
274    int code, val, sign, shift;
275    code = get_vlc2(&s->gb, ff_h263_mv_vlc.table, H263_MV_VLC_BITS, 2);
276
277    if (code == 0)
278        return pred;
279    if (code < 0)
280        return 0xffff;
281
282    sign = get_bits1(&s->gb);
283    shift = f_code - 1;
284    val = code;
285    if (shift) {
286        val = (val - 1) << shift;
287        val |= get_bits(&s->gb, shift);
288        val++;
289    }
290    if (sign)
291        val = -val;
292    val += pred;
293
294    /* modulo decoding */
295    if (!s->h263_long_vectors) {
296        val = sign_extend(val, 5 + f_code);
297    } else {
298        /* horrible H.263 long vector mode */
299        if (pred < -31 && val < -63)
300            val += 64;
301        if (pred > 32 && val > 63)
302            val -= 64;
303
304    }
305    return val;
306}
307
308
309/* Decode RVLC of H.263+ UMV */
310static int h263p_decode_umotion(MpegEncContext * s, int pred)
311{
312   int code = 0, sign;
313
314   if (get_bits1(&s->gb)) /* Motion difference = 0 */
315      return pred;
316
317   code = 2 + get_bits1(&s->gb);
318
319   while (get_bits1(&s->gb))
320   {
321      code <<= 1;
322      code += get_bits1(&s->gb);
323      if (code >= 32768) {
324          avpriv_request_sample(s->avctx, "Huge DMV");
325          return 0xffff;
326      }
327   }
328   sign = code & 1;
329   code >>= 1;
330
331   code = (sign) ? (pred - code) : (pred + code);
332   ff_tlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
333   return code;
334
335}
336
337/**
338 * read the next MVs for OBMC. yes this is an ugly hack, feel free to send a patch :)
339 */
340static void preview_obmc(MpegEncContext *s){
341    GetBitContext gb= s->gb;
342
343    int cbpc, i, pred_x, pred_y, mx, my;
344    int16_t *mot_val;
345    const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
346    const int stride= s->b8_stride*2;
347
348    for(i=0; i<4; i++)
349        s->block_index[i]+= 2;
350    for(i=4; i<6; i++)
351        s->block_index[i]+= 1;
352    s->mb_x++;
353
354    av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
355
356    do{
357        if (get_bits1(&s->gb)) {
358            /* skip mb */
359            mot_val = s->current_picture.motion_val[0][s->block_index[0]];
360            mot_val[0       ]= mot_val[2       ]=
361            mot_val[0+stride]= mot_val[2+stride]= 0;
362            mot_val[1       ]= mot_val[3       ]=
363            mot_val[1+stride]= mot_val[3+stride]= 0;
364
365            s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
366            goto end;
367        }
368        cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
369    }while(cbpc == 20);
370
371    if(cbpc & 4){
372        s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
373    }else{
374        get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
375        if (cbpc & 8) {
376            if(s->modified_quant){
377                if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
378                else                  skip_bits(&s->gb, 5);
379            }else
380                skip_bits(&s->gb, 2);
381        }
382
383        if ((cbpc & 16) == 0) {
384                s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
385                /* 16x16 motion prediction */
386                mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
387                if (s->umvplus)
388                    mx = h263p_decode_umotion(s, pred_x);
389                else
390                    mx = ff_h263_decode_motion(s, pred_x, 1);
391
392                if (s->umvplus)
393                    my = h263p_decode_umotion(s, pred_y);
394                else
395                    my = ff_h263_decode_motion(s, pred_y, 1);
396
397                mot_val[0       ]= mot_val[2       ]=
398                mot_val[0+stride]= mot_val[2+stride]= mx;
399                mot_val[1       ]= mot_val[3       ]=
400                mot_val[1+stride]= mot_val[3+stride]= my;
401        } else {
402            s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
403            for(i=0;i<4;i++) {
404                mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
405                if (s->umvplus)
406                    mx = h263p_decode_umotion(s, pred_x);
407                else
408                    mx = ff_h263_decode_motion(s, pred_x, 1);
409
410                if (s->umvplus)
411                    my = h263p_decode_umotion(s, pred_y);
412                else
413                    my = ff_h263_decode_motion(s, pred_y, 1);
414                if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
415                    skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
416                mot_val[0] = mx;
417                mot_val[1] = my;
418            }
419        }
420    }
421end:
422
423    for(i=0; i<4; i++)
424        s->block_index[i]-= 2;
425    for(i=4; i<6; i++)
426        s->block_index[i]-= 1;
427    s->mb_x--;
428
429    s->gb= gb;
430}
431
432static void h263_decode_dquant(MpegEncContext *s){
433    static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
434
435    if(s->modified_quant){
436        if(get_bits1(&s->gb))
437            s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
438        else
439            s->qscale= get_bits(&s->gb, 5);
440    }else
441        s->qscale += quant_tab[get_bits(&s->gb, 2)];
442    ff_set_qscale(s, s->qscale);
443}
444
445static void h263_pred_acdc(MpegEncContext * s, int16_t *block, int n)
446{
447    int x, y, wrap, a, c, pred_dc, scale;
448    int16_t *dc_val, *ac_val, *ac_val1;
449
450    /* find prediction */
451    if (n < 4) {
452        x = 2 * s->mb_x + (n & 1);
453        y = 2 * s->mb_y + (n>> 1);
454        wrap = s->b8_stride;
455        dc_val = s->dc_val[0];
456        ac_val = s->ac_val[0][0];
457        scale = s->y_dc_scale;
458    } else {
459        x = s->mb_x;
460        y = s->mb_y;
461        wrap = s->mb_stride;
462        dc_val = s->dc_val[n - 4 + 1];
463        ac_val = s->ac_val[n - 4 + 1][0];
464        scale = s->c_dc_scale;
465    }
466
467    ac_val += ((y) * wrap + (x)) * 16;
468    ac_val1 = ac_val;
469
470    /* B C
471     * A X
472     */
473    a = dc_val[(x - 1) + (y) * wrap];
474    c = dc_val[(x) + (y - 1) * wrap];
475
476    /* No prediction outside GOB boundary */
477    if (s->first_slice_line && n != 3) {
478        if (n != 2) c= 1024;
479        if (n != 1 && s->mb_x == s->resync_mb_x) a= 1024;
480    }
481
482    if (s->ac_pred) {
483        pred_dc = 1024;
484        if (s->h263_aic_dir) {
485            /* left prediction */
486            if (a != 1024) {
487                ac_val -= 16;
488                for (int i = 1; i < 8; i++) {
489                    block[s->idsp.idct_permutation[i << 3]] += ac_val[i];
490                }
491                pred_dc = a;
492            }
493        } else {
494            /* top prediction */
495            if (c != 1024) {
496                ac_val -= 16 * wrap;
497                for (int i = 1; i < 8; i++) {
498                    block[s->idsp.idct_permutation[i]] += ac_val[i + 8];
499                }
500                pred_dc = c;
501            }
502        }
503    } else {
504        /* just DC prediction */
505        if (a != 1024 && c != 1024)
506            pred_dc = (a + c) >> 1;
507        else if (a != 1024)
508            pred_dc = a;
509        else
510            pred_dc = c;
511    }
512
513    /* we assume pred is positive */
514    block[0] = block[0] * scale + pred_dc;
515
516    if (block[0] < 0)
517        block[0] = 0;
518    else
519        block[0] |= 1;
520
521    /* Update AC/DC tables */
522    dc_val[(x) + (y) * wrap] = block[0];
523
524    /* left copy */
525    for (int i = 1; i < 8; i++)
526        ac_val1[i]     = block[s->idsp.idct_permutation[i << 3]];
527    /* top copy */
528    for (int i = 1; i < 8; i++)
529        ac_val1[8 + i] = block[s->idsp.idct_permutation[i]];
530}
531
532static int h263_decode_block(MpegEncContext * s, int16_t * block,
533                             int n, int coded)
534{
535    int level, i, j, run;
536    RLTable *rl = &ff_h263_rl_inter;
537    const uint8_t *scan_table;
538    GetBitContext gb= s->gb;
539
540    scan_table = s->intra_scantable.permutated;
541    if (s->h263_aic && s->mb_intra) {
542        rl = &ff_rl_intra_aic;
543        i = 0;
544        if (s->ac_pred) {
545            if (s->h263_aic_dir)
546                scan_table = s->intra_v_scantable.permutated; /* left */
547            else
548                scan_table = s->intra_h_scantable.permutated; /* top */
549        }
550    } else if (s->mb_intra) {
551        /* DC coef */
552        if (CONFIG_RV10_DECODER && s->codec_id == AV_CODEC_ID_RV10) {
553          if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
554            int component, diff;
555            component = (n <= 3 ? 0 : n - 4 + 1);
556            level = s->last_dc[component];
557            if (s->rv10_first_dc_coded[component]) {
558                diff = ff_rv_decode_dc(s, n);
559                if (diff < 0)
560                    return -1;
561                level += diff;
562                level = level & 0xff; /* handle wrap round */
563                s->last_dc[component] = level;
564            } else {
565                s->rv10_first_dc_coded[component] = 1;
566            }
567          } else {
568                level = get_bits(&s->gb, 8);
569                if (level == 255)
570                    level = 128;
571          }
572        }else{
573            level = get_bits(&s->gb, 8);
574            if((level&0x7F) == 0){
575                av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
576                if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
577                    return -1;
578            }
579            if (level == 255)
580                level = 128;
581        }
582        block[0] = level;
583        i = 1;
584    } else {
585        i = 0;
586    }
587    if (!coded) {
588        if (s->mb_intra && s->h263_aic)
589            goto not_coded;
590        s->block_last_index[n] = i - 1;
591        return 0;
592    }
593retry:
594    {
595    OPEN_READER(re, &s->gb);
596    i--; // offset by -1 to allow direct indexing of scan_table
597    for(;;) {
598        UPDATE_CACHE(re, &s->gb);
599        GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
600        if (run == 66) {
601            if (level){
602                CLOSE_READER(re, &s->gb);
603                av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
604                return -1;
605            }
606            /* escape */
607            if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
608                int is11 = SHOW_UBITS(re, &s->gb, 1);
609                SKIP_CACHE(re, &s->gb, 1);
610                run = SHOW_UBITS(re, &s->gb, 7) + 1;
611                if (is11) {
612                    SKIP_COUNTER(re, &s->gb, 1 + 7);
613                    UPDATE_CACHE(re, &s->gb);
614                    level = SHOW_SBITS(re, &s->gb, 11);
615                    SKIP_COUNTER(re, &s->gb, 11);
616                } else {
617                    SKIP_CACHE(re, &s->gb, 7);
618                    level = SHOW_SBITS(re, &s->gb, 7);
619                    SKIP_COUNTER(re, &s->gb, 1 + 7 + 7);
620                }
621            } else {
622                run = SHOW_UBITS(re, &s->gb, 7) + 1;
623                SKIP_CACHE(re, &s->gb, 7);
624                level = (int8_t)SHOW_UBITS(re, &s->gb, 8);
625                SKIP_COUNTER(re, &s->gb, 7 + 8);
626                if(level == -128){
627                    UPDATE_CACHE(re, &s->gb);
628                    if (s->codec_id == AV_CODEC_ID_RV10) {
629                        /* XXX: should patch encoder too */
630                        level = SHOW_SBITS(re, &s->gb, 12);
631                        SKIP_COUNTER(re, &s->gb, 12);
632                    }else{
633                        level = SHOW_UBITS(re, &s->gb, 5);
634                        SKIP_CACHE(re, &s->gb, 5);
635                        level |= SHOW_SBITS(re, &s->gb, 6) * (1<<5);
636                        SKIP_COUNTER(re, &s->gb, 5 + 6);
637                    }
638                }
639            }
640        } else {
641            if (SHOW_UBITS(re, &s->gb, 1))
642                level = -level;
643            SKIP_COUNTER(re, &s->gb, 1);
644        }
645        i += run;
646        if (i >= 64){
647            CLOSE_READER(re, &s->gb);
648            // redo update without last flag, revert -1 offset
649            i = i - run + ((run-1)&63) + 1;
650            if (i < 64) {
651                // only last marker, no overrun
652                block[scan_table[i]] = level;
653                break;
654            }
655            if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
656                //Looks like a hack but no, it's the way it is supposed to work ...
657                rl = &ff_rl_intra_aic;
658                i = 0;
659                s->gb= gb;
660                s->bdsp.clear_block(block);
661                goto retry;
662            }
663            av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
664            return -1;
665        }
666        j = scan_table[i];
667        block[j] = level;
668    }
669    }
670not_coded:
671    if (s->mb_intra && s->h263_aic) {
672        h263_pred_acdc(s, block, n);
673        i = 63;
674    }
675    s->block_last_index[n] = i;
676    return 0;
677}
678
679static int h263_skip_b_part(MpegEncContext *s, int cbp)
680{
681    LOCAL_ALIGNED_32(int16_t, dblock, [64]);
682    int i, mbi;
683    int bli[6];
684
685    /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
686     * but real value should be restored in order to be used later (in OBMC condition)
687     */
688    mbi = s->mb_intra;
689    memcpy(bli, s->block_last_index, sizeof(bli));
690    s->mb_intra = 0;
691    for (i = 0; i < 6; i++) {
692        if (h263_decode_block(s, dblock, i, cbp&32) < 0)
693            return -1;
694        cbp+=cbp;
695    }
696    s->mb_intra = mbi;
697    memcpy(s->block_last_index, bli, sizeof(bli));
698    return 0;
699}
700
701static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
702{
703    int c, mv = 1;
704
705    if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
706        c = get_bits1(gb);
707        if (pb_frame == 2 && c)
708            mv = !get_bits1(gb);
709    } else { // h.263 Annex M improved PB-frame
710        mv = get_unary(gb, 0, 4) + 1;
711        c = mv & 1;
712        mv = !!(mv & 2);
713    }
714    if(c)
715        *cbpb = get_bits(gb, 6);
716    return mv;
717}
718
719#define tab_size ((signed)FF_ARRAY_ELEMS(s->direct_scale_mv[0]))
720#define tab_bias (tab_size / 2)
721static inline void set_one_direct_mv(MpegEncContext *s, Picture *p, int i)
722{
723    int xy           = s->block_index[i];
724    uint16_t time_pp = s->pp_time;
725    uint16_t time_pb = s->pb_time;
726    int p_mx, p_my;
727
728    p_mx = p->motion_val[0][xy][0];
729    if ((unsigned)(p_mx + tab_bias) < tab_size) {
730        s->mv[0][i][0] = s->direct_scale_mv[0][p_mx + tab_bias];
731        s->mv[1][i][0] = s->direct_scale_mv[1][p_mx + tab_bias];
732    } else {
733        s->mv[0][i][0] = p_mx * time_pb / time_pp;
734        s->mv[1][i][0] = p_mx * (time_pb - time_pp) / time_pp;
735    }
736    p_my = p->motion_val[0][xy][1];
737    if ((unsigned)(p_my + tab_bias) < tab_size) {
738        s->mv[0][i][1] = s->direct_scale_mv[0][p_my + tab_bias];
739        s->mv[1][i][1] = s->direct_scale_mv[1][p_my + tab_bias];
740    } else {
741        s->mv[0][i][1] = p_my * time_pb / time_pp;
742        s->mv[1][i][1] = p_my * (time_pb - time_pp) / time_pp;
743    }
744}
745
746/**
747 * @return the mb_type
748 */
749static int set_direct_mv(MpegEncContext *s)
750{
751    const int mb_index = s->mb_x + s->mb_y * s->mb_stride;
752    Picture *p = &s->next_picture;
753    int colocated_mb_type = p->mb_type[mb_index];
754    int i;
755
756    if (s->codec_tag == AV_RL32("U263") && p->f->pict_type == AV_PICTURE_TYPE_I) {
757        p = &s->last_picture;
758        colocated_mb_type = p->mb_type[mb_index];
759    }
760
761    if (IS_8X8(colocated_mb_type)) {
762        s->mv_type = MV_TYPE_8X8;
763        for (i = 0; i < 4; i++)
764            set_one_direct_mv(s, p, i);
765        return MB_TYPE_DIRECT2 | MB_TYPE_8x8 | MB_TYPE_L0L1;
766    } else {
767        set_one_direct_mv(s, p, 0);
768        s->mv[0][1][0] =
769        s->mv[0][2][0] =
770        s->mv[0][3][0] = s->mv[0][0][0];
771        s->mv[0][1][1] =
772        s->mv[0][2][1] =
773        s->mv[0][3][1] = s->mv[0][0][1];
774        s->mv[1][1][0] =
775        s->mv[1][2][0] =
776        s->mv[1][3][0] = s->mv[1][0][0];
777        s->mv[1][1][1] =
778        s->mv[1][2][1] =
779        s->mv[1][3][1] = s->mv[1][0][1];
780        s->mv_type = MV_TYPE_8X8;
781        // Note see prev line
782        return MB_TYPE_DIRECT2 | MB_TYPE_16x16 | MB_TYPE_L0L1;
783    }
784}
785
786int ff_h263_decode_mb(MpegEncContext *s,
787                      int16_t block[6][64])
788{
789    int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
790    int16_t *mot_val;
791    const int xy= s->mb_x + s->mb_y * s->mb_stride;
792    int cbpb = 0, pb_mv_count = 0;
793
794    av_assert2(!s->h263_pred);
795
796    if (s->pict_type == AV_PICTURE_TYPE_P) {
797        do{
798            if (get_bits1(&s->gb)) {
799                /* skip mb */
800                s->mb_intra = 0;
801                for(i=0;i<6;i++)
802                    s->block_last_index[i] = -1;
803                s->mv_dir = MV_DIR_FORWARD;
804                s->mv_type = MV_TYPE_16X16;
805                s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
806                s->mv[0][0][0] = 0;
807                s->mv[0][0][1] = 0;
808                s->mb_skipped = !(s->obmc | s->loop_filter);
809                goto end;
810            }
811            cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
812            if (cbpc < 0){
813                av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
814                return SLICE_ERROR;
815            }
816        }while(cbpc == 20);
817
818        s->bdsp.clear_blocks(s->block[0]);
819
820        dquant = cbpc & 8;
821        s->mb_intra = ((cbpc & 4) != 0);
822        if (s->mb_intra) goto intra;
823
824        if(s->pb_frame && get_bits1(&s->gb))
825            pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
826        cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
827
828        if (cbpy < 0) {
829            av_log(s->avctx, AV_LOG_ERROR, "cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
830            return SLICE_ERROR;
831        }
832
833        if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
834            cbpy ^= 0xF;
835
836        cbp = (cbpc & 3) | (cbpy << 2);
837        if (dquant) {
838            h263_decode_dquant(s);
839        }
840
841        s->mv_dir = MV_DIR_FORWARD;
842        if ((cbpc & 16) == 0) {
843            s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
844            /* 16x16 motion prediction */
845            s->mv_type = MV_TYPE_16X16;
846            ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
847            if (s->umvplus)
848               mx = h263p_decode_umotion(s, pred_x);
849            else
850               mx = ff_h263_decode_motion(s, pred_x, 1);
851
852            if (mx >= 0xffff)
853                return SLICE_ERROR;
854
855            if (s->umvplus)
856               my = h263p_decode_umotion(s, pred_y);
857            else
858               my = ff_h263_decode_motion(s, pred_y, 1);
859
860            if (my >= 0xffff)
861                return SLICE_ERROR;
862            s->mv[0][0][0] = mx;
863            s->mv[0][0][1] = my;
864
865            if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
866               skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
867        } else {
868            s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
869            s->mv_type = MV_TYPE_8X8;
870            for(i=0;i<4;i++) {
871                mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
872                if (s->umvplus)
873                    mx = h263p_decode_umotion(s, pred_x);
874                else
875                    mx = ff_h263_decode_motion(s, pred_x, 1);
876                if (mx >= 0xffff)
877                    return SLICE_ERROR;
878
879                if (s->umvplus)
880                    my = h263p_decode_umotion(s, pred_y);
881                else
882                    my = ff_h263_decode_motion(s, pred_y, 1);
883                if (my >= 0xffff)
884                    return SLICE_ERROR;
885                s->mv[0][i][0] = mx;
886                s->mv[0][i][1] = my;
887                if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
888                  skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
889                mot_val[0] = mx;
890                mot_val[1] = my;
891            }
892        }
893    } else if(s->pict_type==AV_PICTURE_TYPE_B) {
894        int mb_type;
895        const int stride= s->b8_stride;
896        int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
897        int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
898//        const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
899
900        //FIXME ugly
901        mot_val0[0       ]= mot_val0[2       ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
902        mot_val0[1       ]= mot_val0[3       ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
903        mot_val1[0       ]= mot_val1[2       ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
904        mot_val1[1       ]= mot_val1[3       ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
905
906        do{
907            mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
908            if (mb_type < 0){
909                av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
910                return SLICE_ERROR;
911            }
912
913            mb_type= h263_mb_type_b_map[ mb_type ];
914        }while(!mb_type);
915
916        s->mb_intra = IS_INTRA(mb_type);
917        if(HAS_CBP(mb_type)){
918            s->bdsp.clear_blocks(s->block[0]);
919            cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
920            if(s->mb_intra){
921                dquant = IS_QUANT(mb_type);
922                goto intra;
923            }
924
925            cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
926
927            if (cbpy < 0){
928                av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
929                return SLICE_ERROR;
930            }
931
932            if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
933                cbpy ^= 0xF;
934
935            cbp = (cbpc & 3) | (cbpy << 2);
936        }else
937            cbp=0;
938
939        av_assert2(!s->mb_intra);
940
941        if(IS_QUANT(mb_type)){
942            h263_decode_dquant(s);
943        }
944
945        if(IS_DIRECT(mb_type)){
946            s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
947            mb_type |= set_direct_mv(s);
948        }else{
949            s->mv_dir = 0;
950            s->mv_type= MV_TYPE_16X16;
951//FIXME UMV
952
953            if(USES_LIST(mb_type, 0)){
954                int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
955                s->mv_dir = MV_DIR_FORWARD;
956
957                if (s->umvplus)
958                    mx = h263p_decode_umotion(s, pred_x);
959                else
960                    mx = ff_h263_decode_motion(s, pred_x, 1);
961                if (mx >= 0xffff)
962                    return SLICE_ERROR;
963
964                if (s->umvplus)
965                    my = h263p_decode_umotion(s, pred_y);
966                else
967                    my = ff_h263_decode_motion(s, pred_y, 1);
968                if (my >= 0xffff)
969                    return SLICE_ERROR;
970
971                if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
972                    skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
973
974                s->mv[0][0][0] = mx;
975                s->mv[0][0][1] = my;
976                mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
977                mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
978            }
979
980            if(USES_LIST(mb_type, 1)){
981                int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &pred_x, &pred_y);
982                s->mv_dir |= MV_DIR_BACKWARD;
983
984                if (s->umvplus)
985                    mx = h263p_decode_umotion(s, pred_x);
986                else
987                    mx = ff_h263_decode_motion(s, pred_x, 1);
988                if (mx >= 0xffff)
989                    return SLICE_ERROR;
990
991                if (s->umvplus)
992                    my = h263p_decode_umotion(s, pred_y);
993                else
994                    my = ff_h263_decode_motion(s, pred_y, 1);
995                if (my >= 0xffff)
996                    return SLICE_ERROR;
997
998                if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
999                    skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
1000
1001                s->mv[1][0][0] = mx;
1002                s->mv[1][0][1] = my;
1003                mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
1004                mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
1005            }
1006        }
1007
1008        s->current_picture.mb_type[xy] = mb_type;
1009    } else { /* I-Frame */
1010        do{
1011            cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1012            if (cbpc < 0){
1013                av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1014                return SLICE_ERROR;
1015            }
1016        }while(cbpc == 8);
1017
1018        s->bdsp.clear_blocks(s->block[0]);
1019
1020        dquant = cbpc & 4;
1021        s->mb_intra = 1;
1022intra:
1023        s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
1024        if (s->h263_aic) {
1025            s->ac_pred = get_bits1(&s->gb);
1026            if(s->ac_pred){
1027                s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1028
1029                s->h263_aic_dir = get_bits1(&s->gb);
1030            }
1031        }else
1032            s->ac_pred = 0;
1033
1034        if(s->pb_frame && get_bits1(&s->gb))
1035            pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
1036        cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1037        if(cbpy<0){
1038            av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1039            return SLICE_ERROR;
1040        }
1041        cbp = (cbpc & 3) | (cbpy << 2);
1042        if (dquant) {
1043            h263_decode_dquant(s);
1044        }
1045
1046        pb_mv_count += !!s->pb_frame;
1047    }
1048
1049    while(pb_mv_count--){
1050        ff_h263_decode_motion(s, 0, 1);
1051        ff_h263_decode_motion(s, 0, 1);
1052    }
1053
1054    /* decode each block */
1055    for (i = 0; i < 6; i++) {
1056        if (h263_decode_block(s, block[i], i, cbp&32) < 0)
1057            return -1;
1058        cbp+=cbp;
1059    }
1060
1061    if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
1062        return -1;
1063    if(s->obmc && !s->mb_intra){
1064        if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
1065            preview_obmc(s);
1066    }
1067end:
1068
1069    if (get_bits_left(&s->gb) < 0)
1070        return AVERROR_INVALIDDATA;
1071
1072        /* per-MB end of slice check */
1073    {
1074        int v= show_bits(&s->gb, 16);
1075
1076        if (get_bits_left(&s->gb) < 16) {
1077            v >>= 16 - get_bits_left(&s->gb);
1078        }
1079
1080        if(v==0)
1081            return SLICE_END;
1082    }
1083
1084    return SLICE_OK;
1085}
1086
1087/* Most is hardcoded; should extend to handle all H.263 streams. */
1088int ff_h263_decode_picture_header(MpegEncContext *s)
1089{
1090    int format, width, height, i, ret;
1091    uint32_t startcode;
1092
1093    align_get_bits(&s->gb);
1094
1095    if (show_bits(&s->gb, 2) == 2 && s->avctx->frame_number == 0) {
1096         av_log(s->avctx, AV_LOG_WARNING, "Header looks like RTP instead of H.263\n");
1097    }
1098
1099    startcode= get_bits(&s->gb, 22-8);
1100
1101    for(i= get_bits_left(&s->gb); i>24; i-=8) {
1102        startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
1103
1104        if(startcode == 0x20)
1105            break;
1106    }
1107
1108    if (startcode != 0x20) {
1109        av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
1110        return -1;
1111    }
1112    /* temporal reference */
1113    i = get_bits(&s->gb, 8); /* picture timestamp */
1114
1115    i -= (i - (s->picture_number & 0xFF) + 128) & ~0xFF;
1116
1117    s->picture_number= (s->picture_number&~0xFF) + i;
1118
1119    /* PTYPE starts here */
1120    if (check_marker(s->avctx, &s->gb, "in PTYPE") != 1) {
1121        return -1;
1122    }
1123    if (get_bits1(&s->gb) != 0) {
1124        av_log(s->avctx, AV_LOG_ERROR, "Bad H.263 id\n");
1125        return -1;      /* H.263 id */
1126    }
1127    skip_bits1(&s->gb);         /* split screen off */
1128    skip_bits1(&s->gb);         /* camera  off */
1129    skip_bits1(&s->gb);         /* freeze picture release off */
1130
1131    format = get_bits(&s->gb, 3);
1132    /*
1133        0    forbidden
1134        1    sub-QCIF
1135        10   QCIF
1136        7       extended PTYPE (PLUSPTYPE)
1137    */
1138
1139    if (format != 7 && format != 6) {
1140        s->h263_plus = 0;
1141        /* H.263v1 */
1142        width = ff_h263_format[format][0];
1143        height = ff_h263_format[format][1];
1144        if (!width)
1145            return -1;
1146
1147        s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
1148
1149        s->h263_long_vectors = get_bits1(&s->gb);
1150
1151        if (get_bits1(&s->gb) != 0) {
1152            av_log(s->avctx, AV_LOG_ERROR, "H.263 SAC not supported\n");
1153            return -1; /* SAC: off */
1154        }
1155        s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
1156
1157        s->pb_frame = get_bits1(&s->gb);
1158        s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
1159        skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
1160
1161        s->width = width;
1162        s->height = height;
1163        s->avctx->sample_aspect_ratio= (AVRational){12,11};
1164        s->avctx->framerate = (AVRational){ 30000, 1001 };
1165    } else {
1166        int ufep;
1167
1168        /* H.263v2 */
1169        s->h263_plus = 1;
1170        ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
1171
1172        /* ufep other than 0 and 1 are reserved */
1173        if (ufep == 1) {
1174            /* OPPTYPE */
1175            format = get_bits(&s->gb, 3);
1176            ff_dlog(s->avctx, "ufep=1, format: %d\n", format);
1177            s->custom_pcf= get_bits1(&s->gb);
1178            s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
1179            if (get_bits1(&s->gb) != 0) {
1180                av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
1181            }
1182            s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
1183            s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
1184            s->loop_filter= get_bits1(&s->gb);
1185            if(s->avctx->lowres)
1186                s->loop_filter = 0;
1187
1188            s->h263_slice_structured= get_bits1(&s->gb);
1189            if (get_bits1(&s->gb) != 0) {
1190                av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
1191            }
1192            if (get_bits1(&s->gb) != 0) {
1193                av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
1194            }
1195            s->alt_inter_vlc= get_bits1(&s->gb);
1196            s->modified_quant= get_bits1(&s->gb);
1197            if(s->modified_quant)
1198                s->chroma_qscale_table= ff_h263_chroma_qscale_table;
1199
1200            skip_bits(&s->gb, 1); /* Prevent start code emulation */
1201
1202            skip_bits(&s->gb, 3); /* Reserved */
1203        } else if (ufep != 0) {
1204            av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
1205            return -1;
1206        }
1207
1208        /* MPPTYPE */
1209        s->pict_type = get_bits(&s->gb, 3);
1210        switch(s->pict_type){
1211        case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
1212        case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
1213        case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
1214        case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
1215        case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
1216        default:
1217            return -1;
1218        }
1219        skip_bits(&s->gb, 2);
1220        s->no_rounding = get_bits1(&s->gb);
1221        skip_bits(&s->gb, 4);
1222
1223        /* Get the picture dimensions */
1224        if (ufep) {
1225            if (format == 6) {
1226                /* Custom Picture Format (CPFMT) */
1227                int aspect_ratio_info = get_bits(&s->gb, 4);
1228                ff_dlog(s->avctx, "aspect: %d\n", aspect_ratio_info);
1229                /* aspect ratios:
1230                0 - forbidden
1231                1 - 1:1
1232                2 - 12:11 (CIF 4:3)
1233                3 - 10:11 (525-type 4:3)
1234                4 - 16:11 (CIF 16:9)
1235                5 - 40:33 (525-type 16:9)
1236                6-14 - reserved
1237                */
1238                width = (get_bits(&s->gb, 9) + 1) * 4;
1239                check_marker(s->avctx, &s->gb, "in dimensions");
1240                height = get_bits(&s->gb, 9) * 4;
1241                ff_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1242                if (aspect_ratio_info == FF_ASPECT_EXTENDED) {
1243                    /* expected dimensions */
1244                    s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1245                    s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1246                }else{
1247                    s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[aspect_ratio_info];
1248                }
1249            } else {
1250                width = ff_h263_format[format][0];
1251                height = ff_h263_format[format][1];
1252                s->avctx->sample_aspect_ratio= (AVRational){12,11};
1253            }
1254            s->avctx->sample_aspect_ratio.den <<= s->ehc_mode;
1255            if ((width == 0) || (height == 0))
1256                return -1;
1257            s->width = width;
1258            s->height = height;
1259
1260            if(s->custom_pcf){
1261                int gcd;
1262                s->avctx->framerate.num  = 1800000;
1263                s->avctx->framerate.den  = 1000 + get_bits1(&s->gb);
1264                s->avctx->framerate.den *= get_bits(&s->gb, 7);
1265                if(s->avctx->framerate.den == 0){
1266                    av_log(s, AV_LOG_ERROR, "zero framerate\n");
1267                    return -1;
1268                }
1269                gcd= av_gcd(s->avctx->framerate.den, s->avctx->framerate.num);
1270                s->avctx->framerate.den /= gcd;
1271                s->avctx->framerate.num /= gcd;
1272            }else{
1273                s->avctx->framerate = (AVRational){ 30000, 1001 };
1274            }
1275        }
1276
1277        if(s->custom_pcf){
1278            skip_bits(&s->gb, 2); //extended Temporal reference
1279        }
1280
1281        if (ufep) {
1282            if (s->umvplus) {
1283                if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
1284                    skip_bits1(&s->gb);
1285            }
1286            if(s->h263_slice_structured){
1287                if (get_bits1(&s->gb) != 0) {
1288                    av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
1289                }
1290                if (get_bits1(&s->gb) != 0) {
1291                    av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1292                }
1293            }
1294            if (s->pict_type == AV_PICTURE_TYPE_B) {
1295                skip_bits(&s->gb, 4); //ELNUM
1296                if (ufep == 1) {
1297                    skip_bits(&s->gb, 4); // RLNUM
1298                }
1299            }
1300        }
1301
1302        s->qscale = get_bits(&s->gb, 5);
1303    }
1304
1305    if ((ret = av_image_check_size(s->width, s->height, 0, s)) < 0)
1306        return ret;
1307
1308    if (!(s->avctx->flags2 & AV_CODEC_FLAG2_CHUNKS)) {
1309        if ((s->width * s->height / 256 / 8) > get_bits_left(&s->gb))
1310            return AVERROR_INVALIDDATA;
1311    }
1312
1313    s->mb_width = (s->width  + 15) / 16;
1314    s->mb_height = (s->height  + 15) / 16;
1315    s->mb_num = s->mb_width * s->mb_height;
1316
1317    if (s->pb_frame) {
1318        skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1319        if (s->custom_pcf)
1320            skip_bits(&s->gb, 2); //extended Temporal reference
1321        skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1322    }
1323
1324    if (s->pict_type!=AV_PICTURE_TYPE_B) {
1325        s->time            = s->picture_number;
1326        s->pp_time         = s->time - s->last_non_b_time;
1327        s->last_non_b_time = s->time;
1328    }else{
1329        s->time    = s->picture_number;
1330        s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
1331        if (s->pp_time <=s->pb_time ||
1332            s->pp_time <= s->pp_time - s->pb_time ||
1333            s->pp_time <= 0){
1334            s->pp_time = 2;
1335            s->pb_time = 1;
1336        }
1337        ff_mpeg4_init_direct_mv(s);
1338    }
1339
1340    /* PEI */
1341    if (skip_1stop_8data_bits(&s->gb) < 0)
1342        return AVERROR_INVALIDDATA;
1343
1344    if(s->h263_slice_structured){
1345        if (check_marker(s->avctx, &s->gb, "SEPB1") != 1) {
1346            return -1;
1347        }
1348
1349        ff_h263_decode_mba(s);
1350
1351        if (check_marker(s->avctx, &s->gb, "SEPB2") != 1) {
1352            return -1;
1353        }
1354    }
1355    s->f_code = 1;
1356
1357    if (s->pict_type == AV_PICTURE_TYPE_B)
1358        s->low_delay = 0;
1359
1360    if(s->h263_aic){
1361         s->y_dc_scale_table=
1362         s->c_dc_scale_table= ff_aic_dc_scale_table;
1363    }else{
1364        s->y_dc_scale_table=
1365        s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1366    }
1367
1368        ff_h263_show_pict_info(s);
1369    if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
1370        int i,j;
1371        for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1372        av_log(s->avctx, AV_LOG_DEBUG, "\n");
1373        for(i=0; i<13; i++){
1374            for(j=0; j<3; j++){
1375                int v= get_bits(&s->gb, 8);
1376                v |= get_sbits(&s->gb, 8) * (1 << 8);
1377                av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1378            }
1379            av_log(s->avctx, AV_LOG_DEBUG, "\n");
1380        }
1381        for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1382    }
1383
1384    return 0;
1385}
1386