mpeg4videodec: rewrite the slice end detection of non partitioned packets.
[ffmpeg.git] / libavcodec / mpeg4videodec.c
1 /*
2  * MPEG4 decoder.
3  * Copyright (c) 2000,2001 Fabrice Bellard
4  * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22
23 #include "mpegvideo.h"
24 #include "mpeg4video.h"
25 #include "h263.h"
26 #include "thread.h"
27
28 // The defines below define the number of bits that are read at once for
29 // reading vlc values. Changing these may improve speed and data cache needs
30 // be aware though that decreasing them may need the number of stages that is
31 // passed to get_vlc* to be increased.
32 #define SPRITE_TRAJ_VLC_BITS 6
33 #define DC_VLC_BITS 9
34 #define MB_TYPE_B_VLC_BITS 4
35
36
37 static VLC dc_lum, dc_chrom;
38 static VLC sprite_trajectory;
39 static VLC mb_type_b_vlc;
40
41 static const int mb_type_b_map[4]= {
42     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
43     MB_TYPE_L0L1 | MB_TYPE_16x16,
44     MB_TYPE_L1 | MB_TYPE_16x16,
45     MB_TYPE_L0 | MB_TYPE_16x16,
46 };
47
48 /**
49  * predicts the ac.
50  * @param n block index (0-3 are luma, 4-5 are chroma)
51  * @param dir the ac prediction direction
52  */
53 void mpeg4_pred_ac(MpegEncContext * s, DCTELEM *block, int n,
54                    int dir)
55 {
56     int i;
57     int16_t *ac_val, *ac_val1;
58     int8_t * const qscale_table = s->current_picture.f.qscale_table;
59
60     /* find prediction */
61     ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
62     ac_val1 = ac_val;
63     if (s->ac_pred) {
64         if (dir == 0) {
65             const int xy= s->mb_x-1 + s->mb_y*s->mb_stride;
66             /* left prediction */
67             ac_val -= 16;
68
69             if(s->mb_x==0 || s->qscale == qscale_table[xy] || n==1 || n==3){
70                 /* same qscale */
71                 for(i=1;i<8;i++) {
72                     block[s->dsp.idct_permutation[i<<3]] += ac_val[i];
73                 }
74             }else{
75                 /* different qscale, we must rescale */
76                 for(i=1;i<8;i++) {
77                     block[s->dsp.idct_permutation[i<<3]] += ROUNDED_DIV(ac_val[i]*qscale_table[xy], s->qscale);
78                 }
79             }
80         } else {
81             const int xy= s->mb_x + s->mb_y*s->mb_stride - s->mb_stride;
82             /* top prediction */
83             ac_val -= 16 * s->block_wrap[n];
84
85             if(s->mb_y==0 || s->qscale == qscale_table[xy] || n==2 || n==3){
86                 /* same qscale */
87                 for(i=1;i<8;i++) {
88                     block[s->dsp.idct_permutation[i]] += ac_val[i + 8];
89                 }
90             }else{
91                 /* different qscale, we must rescale */
92                 for(i=1;i<8;i++) {
93                     block[s->dsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8]*qscale_table[xy], s->qscale);
94                 }
95             }
96         }
97     }
98     /* left copy */
99     for(i=1;i<8;i++)
100         ac_val1[i    ] = block[s->dsp.idct_permutation[i<<3]];
101
102     /* top copy */
103     for(i=1;i<8;i++)
104         ac_val1[8 + i] = block[s->dsp.idct_permutation[i   ]];
105
106 }
107
108 /**
109  * check if the next stuff is a resync marker or the end.
110  * @return 0 if not
111  */
112 static inline int mpeg4_is_resync(MpegEncContext *s){
113     int bits_count= get_bits_count(&s->gb);
114     int v= show_bits(&s->gb, 16);
115
116     if(s->workaround_bugs&FF_BUG_NO_PADDING && !s->resync_marker){
117         return 0;
118     }
119
120     while(v<=0xFF){
121         if(s->pict_type==AV_PICTURE_TYPE_B || (v>>(8-s->pict_type)!=1) || s->partitioned_frame)
122             break;
123         skip_bits(&s->gb, 8+s->pict_type);
124         bits_count+= 8+s->pict_type;
125         v= show_bits(&s->gb, 16);
126     }
127
128     if(bits_count + 8 >= s->gb.size_in_bits){
129         v>>=8;
130         v|= 0x7F >> (7-(bits_count&7));
131
132         if(v==0x7F)
133             return s->mb_num;
134     }else{
135         if(v == ff_mpeg4_resync_prefix[bits_count&7]){
136             int len, mb_num;
137             int mb_num_bits= av_log2(s->mb_num - 1) + 1;
138             GetBitContext gb= s->gb;
139
140             skip_bits(&s->gb, 1);
141             align_get_bits(&s->gb);
142
143             for(len=0; len<32; len++){
144                 if(get_bits1(&s->gb)) break;
145             }
146
147             mb_num= get_bits(&s->gb, mb_num_bits);
148             if(!mb_num || mb_num > s->mb_num || get_bits_count(&s->gb)+6 > s->gb.size_in_bits)
149                 mb_num= -1;
150
151             s->gb= gb;
152
153             if(len>=ff_mpeg4_get_video_packet_prefix_length(s))
154                 return mb_num;
155         }
156     }
157     return 0;
158 }
159
160 static void mpeg4_decode_sprite_trajectory(MpegEncContext * s, GetBitContext *gb)
161 {
162     int i;
163     int a= 2<<s->sprite_warping_accuracy;
164     int rho= 3-s->sprite_warping_accuracy;
165     int r=16/a;
166     const int vop_ref[4][2]= {{0,0}, {s->width,0}, {0, s->height}, {s->width, s->height}}; // only true for rectangle shapes
167     int d[4][2]={{0,0}, {0,0}, {0,0}, {0,0}};
168     int sprite_ref[4][2];
169     int virtual_ref[2][2];
170     int w2, h2, w3, h3;
171     int alpha=0, beta=0;
172     int w= s->width;
173     int h= s->height;
174     int min_ab;
175
176     for(i=0; i<s->num_sprite_warping_points; i++){
177         int length;
178         int x=0, y=0;
179
180         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
181         if(length){
182             x= get_xbits(gb, length);
183         }
184         if(!(s->divx_version==500 && s->divx_build==413)) skip_bits1(gb); /* marker bit */
185
186         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
187         if(length){
188             y=get_xbits(gb, length);
189         }
190         skip_bits1(gb); /* marker bit */
191         s->sprite_traj[i][0]= d[i][0]= x;
192         s->sprite_traj[i][1]= d[i][1]= y;
193     }
194     for(; i<4; i++)
195         s->sprite_traj[i][0]= s->sprite_traj[i][1]= 0;
196
197     while((1<<alpha)<w) alpha++;
198     while((1<<beta )<h) beta++; // there seems to be a typo in the mpeg4 std for the definition of w' and h'
199     w2= 1<<alpha;
200     h2= 1<<beta;
201
202 // Note, the 4th point isn't used for GMC
203     if(s->divx_version==500 && s->divx_build==413){
204         sprite_ref[0][0]= a*vop_ref[0][0] + d[0][0];
205         sprite_ref[0][1]= a*vop_ref[0][1] + d[0][1];
206         sprite_ref[1][0]= a*vop_ref[1][0] + d[0][0] + d[1][0];
207         sprite_ref[1][1]= a*vop_ref[1][1] + d[0][1] + d[1][1];
208         sprite_ref[2][0]= a*vop_ref[2][0] + d[0][0] + d[2][0];
209         sprite_ref[2][1]= a*vop_ref[2][1] + d[0][1] + d[2][1];
210     } else {
211         sprite_ref[0][0]= (a>>1)*(2*vop_ref[0][0] + d[0][0]);
212         sprite_ref[0][1]= (a>>1)*(2*vop_ref[0][1] + d[0][1]);
213         sprite_ref[1][0]= (a>>1)*(2*vop_ref[1][0] + d[0][0] + d[1][0]);
214         sprite_ref[1][1]= (a>>1)*(2*vop_ref[1][1] + d[0][1] + d[1][1]);
215         sprite_ref[2][0]= (a>>1)*(2*vop_ref[2][0] + d[0][0] + d[2][0]);
216         sprite_ref[2][1]= (a>>1)*(2*vop_ref[2][1] + d[0][1] + d[2][1]);
217     }
218 /*    sprite_ref[3][0]= (a>>1)*(2*vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
219     sprite_ref[3][1]= (a>>1)*(2*vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
220
221 // this is mostly identical to the mpeg4 std (and is totally unreadable because of that ...)
222 // perhaps it should be reordered to be more readable ...
223 // the idea behind this virtual_ref mess is to be able to use shifts later per pixel instead of divides
224 // so the distance between points is converted from w&h based to w2&h2 based which are of the 2^x form
225     virtual_ref[0][0]= 16*(vop_ref[0][0] + w2)
226         + ROUNDED_DIV(((w - w2)*(r*sprite_ref[0][0] - 16*vop_ref[0][0]) + w2*(r*sprite_ref[1][0] - 16*vop_ref[1][0])),w);
227     virtual_ref[0][1]= 16*vop_ref[0][1]
228         + ROUNDED_DIV(((w - w2)*(r*sprite_ref[0][1] - 16*vop_ref[0][1]) + w2*(r*sprite_ref[1][1] - 16*vop_ref[1][1])),w);
229     virtual_ref[1][0]= 16*vop_ref[0][0]
230         + ROUNDED_DIV(((h - h2)*(r*sprite_ref[0][0] - 16*vop_ref[0][0]) + h2*(r*sprite_ref[2][0] - 16*vop_ref[2][0])),h);
231     virtual_ref[1][1]= 16*(vop_ref[0][1] + h2)
232         + ROUNDED_DIV(((h - h2)*(r*sprite_ref[0][1] - 16*vop_ref[0][1]) + h2*(r*sprite_ref[2][1] - 16*vop_ref[2][1])),h);
233
234     switch(s->num_sprite_warping_points)
235     {
236         case 0:
237             s->sprite_offset[0][0]= 0;
238             s->sprite_offset[0][1]= 0;
239             s->sprite_offset[1][0]= 0;
240             s->sprite_offset[1][1]= 0;
241             s->sprite_delta[0][0]= a;
242             s->sprite_delta[0][1]= 0;
243             s->sprite_delta[1][0]= 0;
244             s->sprite_delta[1][1]= a;
245             s->sprite_shift[0]= 0;
246             s->sprite_shift[1]= 0;
247             break;
248         case 1: //GMC only
249             s->sprite_offset[0][0]= sprite_ref[0][0] - a*vop_ref[0][0];
250             s->sprite_offset[0][1]= sprite_ref[0][1] - a*vop_ref[0][1];
251             s->sprite_offset[1][0]= ((sprite_ref[0][0]>>1)|(sprite_ref[0][0]&1)) - a*(vop_ref[0][0]/2);
252             s->sprite_offset[1][1]= ((sprite_ref[0][1]>>1)|(sprite_ref[0][1]&1)) - a*(vop_ref[0][1]/2);
253             s->sprite_delta[0][0]= a;
254             s->sprite_delta[0][1]= 0;
255             s->sprite_delta[1][0]= 0;
256             s->sprite_delta[1][1]= a;
257             s->sprite_shift[0]= 0;
258             s->sprite_shift[1]= 0;
259             break;
260         case 2:
261             s->sprite_offset[0][0]= (sprite_ref[0][0]<<(alpha+rho))
262                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][0])
263                                                   + ( r*sprite_ref[0][1] - virtual_ref[0][1])*(-vop_ref[0][1])
264                                                   + (1<<(alpha+rho-1));
265             s->sprite_offset[0][1]= (sprite_ref[0][1]<<(alpha+rho))
266                                                   + (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-vop_ref[0][0])
267                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][1])
268                                                   + (1<<(alpha+rho-1));
269             s->sprite_offset[1][0]= ( (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][0] + 1)
270                                      +( r*sprite_ref[0][1] - virtual_ref[0][1])*(-2*vop_ref[0][1] + 1)
271                                      +2*w2*r*sprite_ref[0][0]
272                                      - 16*w2
273                                      + (1<<(alpha+rho+1)));
274             s->sprite_offset[1][1]= ( (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-2*vop_ref[0][0] + 1)
275                                      +(-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][1] + 1)
276                                      +2*w2*r*sprite_ref[0][1]
277                                      - 16*w2
278                                      + (1<<(alpha+rho+1)));
279             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
280             s->sprite_delta[0][1]=   (+r*sprite_ref[0][1] - virtual_ref[0][1]);
281             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1]);
282             s->sprite_delta[1][1]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
283
284             s->sprite_shift[0]= alpha+rho;
285             s->sprite_shift[1]= alpha+rho+2;
286             break;
287         case 3:
288             min_ab= FFMIN(alpha, beta);
289             w3= w2>>min_ab;
290             h3= h2>>min_ab;
291             s->sprite_offset[0][0]=  (sprite_ref[0][0]<<(alpha+beta+rho-min_ab))
292                                    + (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-vop_ref[0][0])
293                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-vop_ref[0][1])
294                                    + (1<<(alpha+beta+rho-min_ab-1));
295             s->sprite_offset[0][1]=  (sprite_ref[0][1]<<(alpha+beta+rho-min_ab))
296                                    + (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-vop_ref[0][0])
297                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-vop_ref[0][1])
298                                    + (1<<(alpha+beta+rho-min_ab-1));
299             s->sprite_offset[1][0]=  (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-2*vop_ref[0][0] + 1)
300                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-2*vop_ref[0][1] + 1)
301                                    + 2*w2*h3*r*sprite_ref[0][0]
302                                    - 16*w2*h3
303                                    + (1<<(alpha+beta+rho-min_ab+1));
304             s->sprite_offset[1][1]=  (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-2*vop_ref[0][0] + 1)
305                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-2*vop_ref[0][1] + 1)
306                                    + 2*w2*h3*r*sprite_ref[0][1]
307                                    - 16*w2*h3
308                                    + (1<<(alpha+beta+rho-min_ab+1));
309             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3;
310             s->sprite_delta[0][1]=   (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3;
311             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3;
312             s->sprite_delta[1][1]=   (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3;
313
314             s->sprite_shift[0]= alpha + beta + rho - min_ab;
315             s->sprite_shift[1]= alpha + beta + rho - min_ab + 2;
316             break;
317     }
318     /* try to simplify the situation */
319     if(   s->sprite_delta[0][0] == a<<s->sprite_shift[0]
320        && s->sprite_delta[0][1] == 0
321        && s->sprite_delta[1][0] == 0
322        && s->sprite_delta[1][1] == a<<s->sprite_shift[0])
323     {
324         s->sprite_offset[0][0]>>=s->sprite_shift[0];
325         s->sprite_offset[0][1]>>=s->sprite_shift[0];
326         s->sprite_offset[1][0]>>=s->sprite_shift[1];
327         s->sprite_offset[1][1]>>=s->sprite_shift[1];
328         s->sprite_delta[0][0]= a;
329         s->sprite_delta[0][1]= 0;
330         s->sprite_delta[1][0]= 0;
331         s->sprite_delta[1][1]= a;
332         s->sprite_shift[0]= 0;
333         s->sprite_shift[1]= 0;
334         s->real_sprite_warping_points=1;
335     }
336     else{
337         int shift_y= 16 - s->sprite_shift[0];
338         int shift_c= 16 - s->sprite_shift[1];
339         for(i=0; i<2; i++){
340             s->sprite_offset[0][i]<<= shift_y;
341             s->sprite_offset[1][i]<<= shift_c;
342             s->sprite_delta[0][i]<<= shift_y;
343             s->sprite_delta[1][i]<<= shift_y;
344             s->sprite_shift[i]= 16;
345         }
346         s->real_sprite_warping_points= s->num_sprite_warping_points;
347     }
348 }
349
350 /**
351  * decodes the next video packet.
352  * @return <0 if something went wrong
353  */
354 int mpeg4_decode_video_packet_header(MpegEncContext *s)
355 {
356     int mb_num_bits= av_log2(s->mb_num - 1) + 1;
357     int header_extension=0, mb_num, len;
358
359     /* is there enough space left for a video packet + header */
360     if( get_bits_count(&s->gb) > s->gb.size_in_bits-20) return -1;
361
362     for(len=0; len<32; len++){
363         if(get_bits1(&s->gb)) break;
364     }
365
366     if(len!=ff_mpeg4_get_video_packet_prefix_length(s)){
367         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
368         return -1;
369     }
370
371     if(s->shape != RECT_SHAPE){
372         header_extension= get_bits1(&s->gb);
373         //FIXME more stuff here
374     }
375
376     mb_num= get_bits(&s->gb, mb_num_bits);
377     if(mb_num>=s->mb_num){
378         av_log(s->avctx, AV_LOG_ERROR, "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
379         return -1;
380     }
381
382     s->mb_x= mb_num % s->mb_width;
383     s->mb_y= mb_num / s->mb_width;
384
385     if(s->shape != BIN_ONLY_SHAPE){
386         int qscale= get_bits(&s->gb, s->quant_precision);
387         if(qscale)
388             s->chroma_qscale=s->qscale= qscale;
389     }
390
391     if(s->shape == RECT_SHAPE){
392         header_extension= get_bits1(&s->gb);
393     }
394     if(header_extension){
395         int time_incr=0;
396
397         while (get_bits1(&s->gb) != 0)
398             time_incr++;
399
400         check_marker(&s->gb, "before time_increment in video packed header");
401         skip_bits(&s->gb, s->time_increment_bits); /* time_increment */
402         check_marker(&s->gb, "before vop_coding_type in video packed header");
403
404         skip_bits(&s->gb, 2); /* vop coding type */
405         //FIXME not rect stuff here
406
407         if(s->shape != BIN_ONLY_SHAPE){
408             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
409 //FIXME don't just ignore everything
410             if(s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
411                 mpeg4_decode_sprite_trajectory(s, &s->gb);
412                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
413             }
414
415             //FIXME reduced res stuff here
416
417             if (s->pict_type != AV_PICTURE_TYPE_I) {
418                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
419                 if(f_code==0){
420                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (f_code=0)\n");
421                 }
422             }
423             if (s->pict_type == AV_PICTURE_TYPE_B) {
424                 int b_code = get_bits(&s->gb, 3);
425                 if(b_code==0){
426                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (b_code=0)\n");
427                 }
428             }
429         }
430     }
431     //FIXME new-pred stuff
432
433     return 0;
434 }
435
436 /**
437  * gets the average motion vector for a GMC MB.
438  * @param n either 0 for the x component or 1 for y
439  * @return the average MV for a GMC MB
440  */
441 static inline int get_amv(MpegEncContext *s, int n){
442     int x, y, mb_v, sum, dx, dy, shift;
443     int len = 1 << (s->f_code + 4);
444     const int a= s->sprite_warping_accuracy;
445
446     if(s->workaround_bugs & FF_BUG_AMV)
447         len >>= s->quarter_sample;
448
449     if(s->real_sprite_warping_points==1){
450         if(s->divx_version==500 && s->divx_build==413)
451             sum= s->sprite_offset[0][n] / (1<<(a - s->quarter_sample));
452         else
453             sum= RSHIFT(s->sprite_offset[0][n]<<s->quarter_sample, a);
454     }else{
455         dx= s->sprite_delta[n][0];
456         dy= s->sprite_delta[n][1];
457         shift= s->sprite_shift[0];
458         if(n) dy -= 1<<(shift + a + 1);
459         else  dx -= 1<<(shift + a + 1);
460         mb_v= s->sprite_offset[0][n] + dx*s->mb_x*16 + dy*s->mb_y*16;
461
462         sum=0;
463         for(y=0; y<16; y++){
464             int v;
465
466             v= mb_v + dy*y;
467             //XXX FIXME optimize
468             for(x=0; x<16; x++){
469                 sum+= v>>shift;
470                 v+= dx;
471             }
472         }
473         sum= RSHIFT(sum, a+8-s->quarter_sample);
474     }
475
476     if      (sum < -len) sum= -len;
477     else if (sum >= len) sum= len-1;
478
479     return sum;
480 }
481
482 /**
483  * decodes the dc value.
484  * @param n block index (0-3 are luma, 4-5 are chroma)
485  * @param dir_ptr the prediction direction will be stored here
486  * @return the quantized dc
487  */
488 static inline int mpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
489 {
490     int level, code;
491
492     if (n < 4)
493         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
494     else
495         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
496     if (code < 0 || code > 9 /* && s->nbit<9 */){
497         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
498         return -1;
499     }
500     if (code == 0) {
501         level = 0;
502     } else {
503         if(IS_3IV1){
504             if(code==1)
505                 level= 2*get_bits1(&s->gb)-1;
506             else{
507                 if(get_bits1(&s->gb))
508                     level = get_bits(&s->gb, code-1) + (1<<(code-1));
509                 else
510                     level = -get_bits(&s->gb, code-1) - (1<<(code-1));
511             }
512         }else{
513             level = get_xbits(&s->gb, code);
514         }
515
516         if (code > 8){
517             if(get_bits1(&s->gb)==0){ /* marker */
518                 if(s->error_recognition>=2){
519                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
520                     return -1;
521                 }
522             }
523         }
524     }
525
526     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
527 }
528
529 /**
530  * decodes first partition.
531  * @return number of MBs decoded or <0 if an error occurred
532  */
533 static int mpeg4_decode_partition_a(MpegEncContext *s){
534     int mb_num;
535     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
536
537     /* decode first partition */
538     mb_num=0;
539     s->first_slice_line=1;
540     for(; s->mb_y<s->mb_height; s->mb_y++){
541         ff_init_block_index(s);
542         for(; s->mb_x<s->mb_width; s->mb_x++){
543             const int xy= s->mb_x + s->mb_y*s->mb_stride;
544             int cbpc;
545             int dir=0;
546
547             mb_num++;
548             ff_update_block_index(s);
549             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
550                 s->first_slice_line=0;
551
552             if(s->pict_type==AV_PICTURE_TYPE_I){
553                 int i;
554
555                 do{
556                     if(show_bits_long(&s->gb, 19)==DC_MARKER){
557                         return mb_num-1;
558                     }
559
560                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
561                     if (cbpc < 0){
562                         av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
563                         return -1;
564                     }
565                 }while(cbpc == 8);
566
567                 s->cbp_table[xy]= cbpc & 3;
568                 s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
569                 s->mb_intra = 1;
570
571                 if(cbpc & 4) {
572                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
573                 }
574                 s->current_picture.f.qscale_table[xy]= s->qscale;
575
576                 s->mbintra_table[xy]= 1;
577                 for(i=0; i<6; i++){
578                     int dc_pred_dir;
579                     int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
580                     if(dc < 0){
581                         av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
582                         return -1;
583                     }
584                     dir<<=1;
585                     if(dc_pred_dir) dir|=1;
586                 }
587                 s->pred_dir_table[xy]= dir;
588             }else{ /* P/S_TYPE */
589                 int mx, my, pred_x, pred_y, bits;
590                 int16_t * const mot_val = s->current_picture.f.motion_val[0][s->block_index[0]];
591                 const int stride= s->b8_stride*2;
592
593 try_again:
594                 bits= show_bits(&s->gb, 17);
595                 if(bits==MOTION_MARKER){
596                     return mb_num-1;
597                 }
598                 skip_bits1(&s->gb);
599                 if(bits&0x10000){
600                     /* skip mb */
601                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
602                         s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
603                         mx= get_amv(s, 0);
604                         my= get_amv(s, 1);
605                     }else{
606                         s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
607                         mx=my=0;
608                     }
609                     mot_val[0       ]= mot_val[2       ]=
610                     mot_val[0+stride]= mot_val[2+stride]= mx;
611                     mot_val[1       ]= mot_val[3       ]=
612                     mot_val[1+stride]= mot_val[3+stride]= my;
613
614                     if(s->mbintra_table[xy])
615                         ff_clean_intra_table_entries(s);
616                     continue;
617                 }
618
619                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
620                 if (cbpc < 0){
621                     av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
622                     return -1;
623                 }
624                 if(cbpc == 20)
625                     goto try_again;
626
627                 s->cbp_table[xy]= cbpc&(8+3); //8 is dquant
628
629                 s->mb_intra = ((cbpc & 4) != 0);
630
631                 if(s->mb_intra){
632                     s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
633                     s->mbintra_table[xy]= 1;
634                     mot_val[0       ]= mot_val[2       ]=
635                     mot_val[0+stride]= mot_val[2+stride]= 0;
636                     mot_val[1       ]= mot_val[3       ]=
637                     mot_val[1+stride]= mot_val[3+stride]= 0;
638                 }else{
639                     if(s->mbintra_table[xy])
640                         ff_clean_intra_table_entries(s);
641
642                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
643                         s->mcsel= get_bits1(&s->gb);
644                     else s->mcsel= 0;
645
646                     if ((cbpc & 16) == 0) {
647                         /* 16x16 motion prediction */
648
649                         h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
650                         if(!s->mcsel){
651                             mx = h263_decode_motion(s, pred_x, s->f_code);
652                             if (mx >= 0xffff)
653                                 return -1;
654
655                             my = h263_decode_motion(s, pred_y, s->f_code);
656                             if (my >= 0xffff)
657                                 return -1;
658                             s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
659                         } else {
660                             mx = get_amv(s, 0);
661                             my = get_amv(s, 1);
662                             s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
663                         }
664
665                         mot_val[0       ]= mot_val[2       ] =
666                         mot_val[0+stride]= mot_val[2+stride]= mx;
667                         mot_val[1       ]= mot_val[3       ]=
668                         mot_val[1+stride]= mot_val[3+stride]= my;
669                     } else {
670                         int i;
671                         s->current_picture.f.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
672                         for(i=0;i<4;i++) {
673                             int16_t *mot_val= h263_pred_motion(s, i, 0, &pred_x, &pred_y);
674                             mx = h263_decode_motion(s, pred_x, s->f_code);
675                             if (mx >= 0xffff)
676                                 return -1;
677
678                             my = h263_decode_motion(s, pred_y, s->f_code);
679                             if (my >= 0xffff)
680                                 return -1;
681                             mot_val[0] = mx;
682                             mot_val[1] = my;
683                         }
684                     }
685                 }
686             }
687         }
688         s->mb_x= 0;
689     }
690
691     return mb_num;
692 }
693
694 /**
695  * decode second partition.
696  * @return <0 if an error occurred
697  */
698 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count){
699     int mb_num=0;
700     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
701
702     s->mb_x= s->resync_mb_x;
703     s->first_slice_line=1;
704     for(s->mb_y= s->resync_mb_y; mb_num < mb_count; s->mb_y++){
705         ff_init_block_index(s);
706         for(; mb_num < mb_count && s->mb_x<s->mb_width; s->mb_x++){
707             const int xy= s->mb_x + s->mb_y*s->mb_stride;
708
709             mb_num++;
710             ff_update_block_index(s);
711             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
712                 s->first_slice_line=0;
713
714             if(s->pict_type==AV_PICTURE_TYPE_I){
715                 int ac_pred= get_bits1(&s->gb);
716                 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
717                 if(cbpy<0){
718                     av_log(s->avctx, AV_LOG_ERROR, "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
719                     return -1;
720                 }
721
722                 s->cbp_table[xy]|= cbpy<<2;
723                 s->current_picture.f.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
724             }else{ /* P || S_TYPE */
725                 if (IS_INTRA(s->current_picture.f.mb_type[xy])) {
726                     int dir=0,i;
727                     int ac_pred = get_bits1(&s->gb);
728                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
729
730                     if(cbpy<0){
731                         av_log(s->avctx, AV_LOG_ERROR, "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
732                         return -1;
733                     }
734
735                     if(s->cbp_table[xy] & 8) {
736                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
737                     }
738                     s->current_picture.f.qscale_table[xy] = s->qscale;
739
740                     for(i=0; i<6; i++){
741                         int dc_pred_dir;
742                         int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
743                         if(dc < 0){
744                             av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
745                             return -1;
746                         }
747                         dir<<=1;
748                         if(dc_pred_dir) dir|=1;
749                     }
750                     s->cbp_table[xy]&= 3; //remove dquant
751                     s->cbp_table[xy]|= cbpy<<2;
752                     s->current_picture.f.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
753                     s->pred_dir_table[xy]= dir;
754                 } else if (IS_SKIP(s->current_picture.f.mb_type[xy])) {
755                     s->current_picture.f.qscale_table[xy] = s->qscale;
756                     s->cbp_table[xy]= 0;
757                 }else{
758                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
759
760                     if(cbpy<0){
761                         av_log(s->avctx, AV_LOG_ERROR, "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
762                         return -1;
763                     }
764
765                     if(s->cbp_table[xy] & 8) {
766                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
767                     }
768                     s->current_picture.f.qscale_table[xy] = s->qscale;
769
770                     s->cbp_table[xy]&= 3; //remove dquant
771                     s->cbp_table[xy]|= (cbpy^0xf)<<2;
772                 }
773             }
774         }
775         if(mb_num >= mb_count) return 0;
776         s->mb_x= 0;
777     }
778     return 0;
779 }
780
781 /**
782  * decodes the first & second partition
783  * @return <0 if error (and sets error type in the error_status_table)
784  */
785 int ff_mpeg4_decode_partitions(MpegEncContext *s)
786 {
787     int mb_num;
788     const int part_a_error= s->pict_type==AV_PICTURE_TYPE_I ? (DC_ERROR|MV_ERROR) : MV_ERROR;
789     const int part_a_end  = s->pict_type==AV_PICTURE_TYPE_I ? (DC_END  |MV_END)   : MV_END;
790
791     mb_num= mpeg4_decode_partition_a(s);
792     if(mb_num<0){
793         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
794         return -1;
795     }
796
797     if(s->resync_mb_x + s->resync_mb_y*s->mb_width + mb_num > s->mb_num){
798         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
799         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
800         return -1;
801     }
802
803     s->mb_num_left= mb_num;
804
805     if(s->pict_type==AV_PICTURE_TYPE_I){
806         while(show_bits(&s->gb, 9) == 1)
807             skip_bits(&s->gb, 9);
808         if(get_bits_long(&s->gb, 19)!=DC_MARKER){
809             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first I partition at %d %d\n", s->mb_x, s->mb_y);
810             return -1;
811         }
812     }else{
813         while(show_bits(&s->gb, 10) == 1)
814             skip_bits(&s->gb, 10);
815         if(get_bits(&s->gb, 17)!=MOTION_MARKER){
816             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first P partition at %d %d\n", s->mb_x, s->mb_y);
817             return -1;
818         }
819     }
820     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, part_a_end);
821
822     if( mpeg4_decode_partition_b(s, mb_num) < 0){
823         if(s->pict_type==AV_PICTURE_TYPE_P)
824             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, DC_ERROR);
825         return -1;
826     }else{
827         if(s->pict_type==AV_PICTURE_TYPE_P)
828             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, DC_END);
829     }
830
831     return 0;
832 }
833
834 /**
835  * decodes a block.
836  * @return <0 if an error occurred
837  */
838 static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
839                               int n, int coded, int intra, int rvlc)
840 {
841     int level, i, last, run;
842     int dc_pred_dir;
843     RLTable * rl;
844     RL_VLC_ELEM * rl_vlc;
845     const uint8_t * scan_table;
846     int qmul, qadd;
847
848     //Note intra & rvlc should be optimized away if this is inlined
849
850     if(intra) {
851       if(s->use_intra_dc_vlc){
852         /* DC coef */
853         if(s->partitioned_frame){
854             level = s->dc_val[0][ s->block_index[n] ];
855             if(n<4) level= FASTDIV((level + (s->y_dc_scale>>1)), s->y_dc_scale);
856             else    level= FASTDIV((level + (s->c_dc_scale>>1)), s->c_dc_scale);
857             dc_pred_dir= (s->pred_dir_table[s->mb_x + s->mb_y*s->mb_stride]<<n)&32;
858         }else{
859             level = mpeg4_decode_dc(s, n, &dc_pred_dir);
860             if (level < 0)
861                 return -1;
862         }
863         block[0] = level;
864         i = 0;
865       }else{
866             i = -1;
867             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
868       }
869       if (!coded)
870           goto not_coded;
871
872       if(rvlc){
873           rl = &rvlc_rl_intra;
874           rl_vlc = rvlc_rl_intra.rl_vlc[0];
875       }else{
876           rl = &ff_mpeg4_rl_intra;
877           rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
878       }
879       if (s->ac_pred) {
880           if (dc_pred_dir == 0)
881               scan_table = s->intra_v_scantable.permutated; /* left */
882           else
883               scan_table = s->intra_h_scantable.permutated; /* top */
884       } else {
885             scan_table = s->intra_scantable.permutated;
886       }
887       qmul=1;
888       qadd=0;
889     } else {
890         i = -1;
891         if (!coded) {
892             s->block_last_index[n] = i;
893             return 0;
894         }
895         if(rvlc) rl = &rvlc_rl_inter;
896         else     rl = &ff_h263_rl_inter;
897
898         scan_table = s->intra_scantable.permutated;
899
900         if(s->mpeg_quant){
901             qmul=1;
902             qadd=0;
903             if(rvlc){
904                 rl_vlc = rvlc_rl_inter.rl_vlc[0];
905             }else{
906                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
907             }
908         }else{
909             qmul = s->qscale << 1;
910             qadd = (s->qscale - 1) | 1;
911             if(rvlc){
912                 rl_vlc = rvlc_rl_inter.rl_vlc[s->qscale];
913             }else{
914                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
915             }
916         }
917     }
918   {
919     OPEN_READER(re, &s->gb);
920     for(;;) {
921         UPDATE_CACHE(re, &s->gb);
922         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
923         if (level==0) {
924           /* escape */
925           if(rvlc){
926                 if(SHOW_UBITS(re, &s->gb, 1)==0){
927                     av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in rvlc esc\n");
928                     return -1;
929                 }; SKIP_CACHE(re, &s->gb, 1);
930
931                 last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
932                 run=   SHOW_UBITS(re, &s->gb, 6); LAST_SKIP_CACHE(re, &s->gb, 6);
933                 SKIP_COUNTER(re, &s->gb, 1+1+6);
934                 UPDATE_CACHE(re, &s->gb);
935
936                 if(SHOW_UBITS(re, &s->gb, 1)==0){
937                     av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in rvlc esc\n");
938                     return -1;
939                 }; SKIP_CACHE(re, &s->gb, 1);
940
941                 level= SHOW_UBITS(re, &s->gb, 11); SKIP_CACHE(re, &s->gb, 11);
942
943                 if(SHOW_UBITS(re, &s->gb, 5)!=0x10){
944                     av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
945                     return -1;
946                 }; SKIP_CACHE(re, &s->gb, 5);
947
948                 level=  level * qmul + qadd;
949                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1); LAST_SKIP_CACHE(re, &s->gb, 1);
950                 SKIP_COUNTER(re, &s->gb, 1+11+5+1);
951
952                 i+= run + 1;
953                 if(last) i+=192;
954           }else{
955             int cache;
956             cache= GET_CACHE(re, &s->gb);
957
958             if(IS_3IV1)
959                 cache ^= 0xC0000000;
960
961             if (cache&0x80000000) {
962                 if (cache&0x40000000) {
963                     /* third escape */
964                     SKIP_CACHE(re, &s->gb, 2);
965                     last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
966                     run=   SHOW_UBITS(re, &s->gb, 6); LAST_SKIP_CACHE(re, &s->gb, 6);
967                     SKIP_COUNTER(re, &s->gb, 2+1+6);
968                     UPDATE_CACHE(re, &s->gb);
969
970                     if(IS_3IV1){
971                         level= SHOW_SBITS(re, &s->gb, 12); LAST_SKIP_BITS(re, &s->gb, 12);
972                     }else{
973                         if(SHOW_UBITS(re, &s->gb, 1)==0){
974                             av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in 3. esc\n");
975                             return -1;
976                         }; SKIP_CACHE(re, &s->gb, 1);
977
978                         level= SHOW_SBITS(re, &s->gb, 12); SKIP_CACHE(re, &s->gb, 12);
979
980                         if(SHOW_UBITS(re, &s->gb, 1)==0){
981                             av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in 3. esc\n");
982                             return -1;
983                         }; LAST_SKIP_CACHE(re, &s->gb, 1);
984
985                         SKIP_COUNTER(re, &s->gb, 1+12+1);
986                     }
987
988 #if 0
989                     if(s->error_recognition >= FF_ER_COMPLIANT){
990                         const int abs_level= FFABS(level);
991                         if(abs_level<=MAX_LEVEL && run<=MAX_RUN){
992                             const int run1= run - rl->max_run[last][abs_level] - 1;
993                             if(abs_level <= rl->max_level[last][run]){
994                                 av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
995                                 return -1;
996                             }
997                             if(s->error_recognition > FF_ER_COMPLIANT){
998                                 if(abs_level <= rl->max_level[last][run]*2){
999                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
1000                                     return -1;
1001                                 }
1002                                 if(run1 >= 0 && abs_level <= rl->max_level[last][run1]){
1003                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
1004                                     return -1;
1005                                 }
1006                             }
1007                         }
1008                     }
1009 #endif
1010                     if (level>0) level= level * qmul + qadd;
1011                     else         level= level * qmul - qadd;
1012
1013                     if((unsigned)(level + 2048) > 4095){
1014                         if(s->error_recognition > FF_ER_COMPLIANT){
1015                             if(level > 2560 || level<-2560){
1016                                 av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc, qp=%d\n", s->qscale);
1017                                 return -1;
1018                             }
1019                         }
1020                         level= level<0 ? -2048 : 2047;
1021                     }
1022
1023                     i+= run + 1;
1024                     if(last) i+=192;
1025                 } else {
1026                     /* second escape */
1027                     SKIP_BITS(re, &s->gb, 2);
1028                     GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1029                     i+= run + rl->max_run[run>>7][level/qmul] +1; //FIXME opt indexing
1030                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1031                     LAST_SKIP_BITS(re, &s->gb, 1);
1032                 }
1033             } else {
1034                 /* first escape */
1035                 SKIP_BITS(re, &s->gb, 1);
1036                 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1037                 i+= run;
1038                 level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
1039                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1040                 LAST_SKIP_BITS(re, &s->gb, 1);
1041             }
1042           }
1043         } else {
1044             i+= run;
1045             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1046             LAST_SKIP_BITS(re, &s->gb, 1);
1047         }
1048         if (i > 62){
1049             i-= 192;
1050             if(i&(~63)){
1051                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1052                 return -1;
1053             }
1054
1055             block[scan_table[i]] = level;
1056             break;
1057         }
1058
1059         block[scan_table[i]] = level;
1060     }
1061     CLOSE_READER(re, &s->gb);
1062   }
1063  not_coded:
1064     if (intra) {
1065         if(!s->use_intra_dc_vlc){
1066             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1067
1068             i -= i>>31; //if(i == -1) i=0;
1069         }
1070
1071         mpeg4_pred_ac(s, block, n, dc_pred_dir);
1072         if (s->ac_pred) {
1073             i = 63; /* XXX: not optimal */
1074         }
1075     }
1076     s->block_last_index[n] = i;
1077     return 0;
1078 }
1079
1080 /**
1081  * decode partition C of one MB.
1082  * @return <0 if an error occurred
1083  */
1084 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, DCTELEM block[6][64])
1085 {
1086     int cbp, mb_type;
1087     const int xy= s->mb_x + s->mb_y*s->mb_stride;
1088
1089     mb_type = s->current_picture.f.mb_type[xy];
1090     cbp = s->cbp_table[xy];
1091
1092     s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1093
1094     if (s->current_picture.f.qscale_table[xy] != s->qscale) {
1095         ff_set_qscale(s, s->current_picture.f.qscale_table[xy]);
1096     }
1097
1098     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1099         int i;
1100         for(i=0; i<4; i++){
1101             s->mv[0][i][0] = s->current_picture.f.motion_val[0][s->block_index[i]][0];
1102             s->mv[0][i][1] = s->current_picture.f.motion_val[0][s->block_index[i]][1];
1103         }
1104         s->mb_intra = IS_INTRA(mb_type);
1105
1106         if (IS_SKIP(mb_type)) {
1107             /* skip mb */
1108             for(i=0;i<6;i++)
1109                 s->block_last_index[i] = -1;
1110             s->mv_dir = MV_DIR_FORWARD;
1111             s->mv_type = MV_TYPE_16X16;
1112             if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1113                 s->mcsel=1;
1114                 s->mb_skipped = 0;
1115             }else{
1116                 s->mcsel=0;
1117                 s->mb_skipped = 1;
1118             }
1119         }else if(s->mb_intra){
1120             s->ac_pred = IS_ACPRED(s->current_picture.f.mb_type[xy]);
1121         }else if(!s->mb_intra){
1122 //            s->mcsel= 0; //FIXME do we need to init that
1123
1124             s->mv_dir = MV_DIR_FORWARD;
1125             if (IS_8X8(mb_type)) {
1126                 s->mv_type = MV_TYPE_8X8;
1127             } else {
1128                 s->mv_type = MV_TYPE_16X16;
1129             }
1130         }
1131     } else { /* I-Frame */
1132         s->mb_intra = 1;
1133         s->ac_pred = IS_ACPRED(s->current_picture.f.mb_type[xy]);
1134     }
1135
1136     if (!IS_SKIP(mb_type)) {
1137         int i;
1138         s->dsp.clear_blocks(s->block[0]);
1139         /* decode each block */
1140         for (i = 0; i < 6; i++) {
1141             if(mpeg4_decode_block(s, block[i], i, cbp&32, s->mb_intra, s->rvlc) < 0){
1142                 av_log(s->avctx, AV_LOG_ERROR, "texture corrupted at %d %d %d\n", s->mb_x, s->mb_y, s->mb_intra);
1143                 return -1;
1144             }
1145             cbp+=cbp;
1146         }
1147     }
1148
1149     /* per-MB end of slice check */
1150
1151     if(--s->mb_num_left <= 0){
1152         if(mpeg4_is_resync(s))
1153             return SLICE_END;
1154         else
1155             return SLICE_NOEND;
1156     }else{
1157         if(mpeg4_is_resync(s)){
1158             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1159             if(s->cbp_table[xy+delta])
1160                 return SLICE_END;
1161         }
1162         return SLICE_OK;
1163     }
1164 }
1165
1166 static int mpeg4_decode_mb(MpegEncContext *s,
1167                       DCTELEM block[6][64])
1168 {
1169     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1170     int16_t *mot_val;
1171     static int8_t quant_tab[4] = { -1, -2, 1, 2 };
1172     const int xy= s->mb_x + s->mb_y * s->mb_stride;
1173
1174     assert(s->h263_pred);
1175
1176     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1177         do{
1178             if (get_bits1(&s->gb)) {
1179                 /* skip mb */
1180                 s->mb_intra = 0;
1181                 for(i=0;i<6;i++)
1182                     s->block_last_index[i] = -1;
1183                 s->mv_dir = MV_DIR_FORWARD;
1184                 s->mv_type = MV_TYPE_16X16;
1185                 if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1186                     s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1187                     s->mcsel=1;
1188                     s->mv[0][0][0]= get_amv(s, 0);
1189                     s->mv[0][0][1]= get_amv(s, 1);
1190
1191                     s->mb_skipped = 0;
1192                 }else{
1193                     s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1194                     s->mcsel=0;
1195                     s->mv[0][0][0] = 0;
1196                     s->mv[0][0][1] = 0;
1197                     s->mb_skipped = 1;
1198                 }
1199                 goto end;
1200             }
1201             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1202             if (cbpc < 0){
1203                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1204                 return -1;
1205             }
1206         }while(cbpc == 20);
1207
1208         s->dsp.clear_blocks(s->block[0]);
1209         dquant = cbpc & 8;
1210         s->mb_intra = ((cbpc & 4) != 0);
1211         if (s->mb_intra) goto intra;
1212
1213         if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
1214             s->mcsel= get_bits1(&s->gb);
1215         else s->mcsel= 0;
1216         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1217
1218         cbp = (cbpc & 3) | (cbpy << 2);
1219         if (dquant) {
1220             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1221         }
1222         if((!s->progressive_sequence) && (cbp || (s->workaround_bugs&FF_BUG_XVID_ILACE)))
1223             s->interlaced_dct= get_bits1(&s->gb);
1224
1225         s->mv_dir = MV_DIR_FORWARD;
1226         if ((cbpc & 16) == 0) {
1227             if(s->mcsel){
1228                 s->current_picture.f.mb_type[xy] = MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1229                 /* 16x16 global motion prediction */
1230                 s->mv_type = MV_TYPE_16X16;
1231                 mx= get_amv(s, 0);
1232                 my= get_amv(s, 1);
1233                 s->mv[0][0][0] = mx;
1234                 s->mv[0][0][1] = my;
1235             }else if((!s->progressive_sequence) && get_bits1(&s->gb)){
1236                 s->current_picture.f.mb_type[xy] = MB_TYPE_16x8 | MB_TYPE_L0 | MB_TYPE_INTERLACED;
1237                 /* 16x8 field motion prediction */
1238                 s->mv_type= MV_TYPE_FIELD;
1239
1240                 s->field_select[0][0]= get_bits1(&s->gb);
1241                 s->field_select[0][1]= get_bits1(&s->gb);
1242
1243                 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1244
1245                 for(i=0; i<2; i++){
1246                     mx = h263_decode_motion(s, pred_x, s->f_code);
1247                     if (mx >= 0xffff)
1248                         return -1;
1249
1250                     my = h263_decode_motion(s, pred_y/2, s->f_code);
1251                     if (my >= 0xffff)
1252                         return -1;
1253
1254                     s->mv[0][i][0] = mx;
1255                     s->mv[0][i][1] = my;
1256                 }
1257             }else{
1258                 s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1259                 /* 16x16 motion prediction */
1260                 s->mv_type = MV_TYPE_16X16;
1261                 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1262                 mx = h263_decode_motion(s, pred_x, s->f_code);
1263
1264                 if (mx >= 0xffff)
1265                     return -1;
1266
1267                 my = h263_decode_motion(s, pred_y, s->f_code);
1268
1269                 if (my >= 0xffff)
1270                     return -1;
1271                 s->mv[0][0][0] = mx;
1272                 s->mv[0][0][1] = my;
1273             }
1274         } else {
1275             s->current_picture.f.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1276             s->mv_type = MV_TYPE_8X8;
1277             for(i=0;i<4;i++) {
1278                 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1279                 mx = h263_decode_motion(s, pred_x, s->f_code);
1280                 if (mx >= 0xffff)
1281                     return -1;
1282
1283                 my = h263_decode_motion(s, pred_y, s->f_code);
1284                 if (my >= 0xffff)
1285                     return -1;
1286                 s->mv[0][i][0] = mx;
1287                 s->mv[0][i][1] = my;
1288                 mot_val[0] = mx;
1289                 mot_val[1] = my;
1290             }
1291         }
1292     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
1293         int modb1; // first bit of modb
1294         int modb2; // second bit of modb
1295         int mb_type;
1296
1297         s->mb_intra = 0; //B-frames never contain intra blocks
1298         s->mcsel=0;      //     ...               true gmc blocks
1299
1300         if(s->mb_x==0){
1301             for(i=0; i<2; i++){
1302                 s->last_mv[i][0][0]=
1303                 s->last_mv[i][0][1]=
1304                 s->last_mv[i][1][0]=
1305                 s->last_mv[i][1][1]= 0;
1306             }
1307
1308             ff_thread_await_progress((AVFrame*)s->next_picture_ptr, s->mb_y, 0);
1309         }
1310
1311         /* if we skipped it in the future P Frame than skip it now too */
1312         s->mb_skipped = s->next_picture.f.mbskip_table[s->mb_y * s->mb_stride + s->mb_x]; // Note, skiptab=0 if last was GMC
1313
1314         if(s->mb_skipped){
1315                 /* skip mb */
1316             for(i=0;i<6;i++)
1317                 s->block_last_index[i] = -1;
1318
1319             s->mv_dir = MV_DIR_FORWARD;
1320             s->mv_type = MV_TYPE_16X16;
1321             s->mv[0][0][0] = 0;
1322             s->mv[0][0][1] = 0;
1323             s->mv[1][0][0] = 0;
1324             s->mv[1][0][1] = 0;
1325             s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1326             goto end;
1327         }
1328
1329         modb1= get_bits1(&s->gb);
1330         if(modb1){
1331             mb_type= MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1; //like MB_TYPE_B_DIRECT but no vectors coded
1332             cbp=0;
1333         }else{
1334             modb2= get_bits1(&s->gb);
1335             mb_type= get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1336             if(mb_type<0){
1337                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1338                 return -1;
1339             }
1340             mb_type= mb_type_b_map[ mb_type ];
1341             if(modb2) cbp= 0;
1342             else{
1343                 s->dsp.clear_blocks(s->block[0]);
1344                 cbp= get_bits(&s->gb, 6);
1345             }
1346
1347             if ((!IS_DIRECT(mb_type)) && cbp) {
1348                 if(get_bits1(&s->gb)){
1349                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb)*4 - 2);
1350                 }
1351             }
1352
1353             if(!s->progressive_sequence){
1354                 if(cbp)
1355                     s->interlaced_dct= get_bits1(&s->gb);
1356
1357                 if(!IS_DIRECT(mb_type) && get_bits1(&s->gb)){
1358                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1359                     mb_type &= ~MB_TYPE_16x16;
1360
1361                     if(USES_LIST(mb_type, 0)){
1362                         s->field_select[0][0]= get_bits1(&s->gb);
1363                         s->field_select[0][1]= get_bits1(&s->gb);
1364                     }
1365                     if(USES_LIST(mb_type, 1)){
1366                         s->field_select[1][0]= get_bits1(&s->gb);
1367                         s->field_select[1][1]= get_bits1(&s->gb);
1368                     }
1369                 }
1370             }
1371
1372             s->mv_dir = 0;
1373             if((mb_type & (MB_TYPE_DIRECT2|MB_TYPE_INTERLACED)) == 0){
1374                 s->mv_type= MV_TYPE_16X16;
1375
1376                 if(USES_LIST(mb_type, 0)){
1377                     s->mv_dir = MV_DIR_FORWARD;
1378
1379                     mx = h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1380                     my = h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1381                     s->last_mv[0][1][0]= s->last_mv[0][0][0]= s->mv[0][0][0] = mx;
1382                     s->last_mv[0][1][1]= s->last_mv[0][0][1]= s->mv[0][0][1] = my;
1383                 }
1384
1385                 if(USES_LIST(mb_type, 1)){
1386                     s->mv_dir |= MV_DIR_BACKWARD;
1387
1388                     mx = h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1389                     my = h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1390                     s->last_mv[1][1][0]= s->last_mv[1][0][0]= s->mv[1][0][0] = mx;
1391                     s->last_mv[1][1][1]= s->last_mv[1][0][1]= s->mv[1][0][1] = my;
1392                 }
1393             }else if(!IS_DIRECT(mb_type)){
1394                 s->mv_type= MV_TYPE_FIELD;
1395
1396                 if(USES_LIST(mb_type, 0)){
1397                     s->mv_dir = MV_DIR_FORWARD;
1398
1399                     for(i=0; i<2; i++){
1400                         mx = h263_decode_motion(s, s->last_mv[0][i][0]  , s->f_code);
1401                         my = h263_decode_motion(s, s->last_mv[0][i][1]/2, s->f_code);
1402                         s->last_mv[0][i][0]=  s->mv[0][i][0] = mx;
1403                         s->last_mv[0][i][1]= (s->mv[0][i][1] = my)*2;
1404                     }
1405                 }
1406
1407                 if(USES_LIST(mb_type, 1)){
1408                     s->mv_dir |= MV_DIR_BACKWARD;
1409
1410                     for(i=0; i<2; i++){
1411                         mx = h263_decode_motion(s, s->last_mv[1][i][0]  , s->b_code);
1412                         my = h263_decode_motion(s, s->last_mv[1][i][1]/2, s->b_code);
1413                         s->last_mv[1][i][0]=  s->mv[1][i][0] = mx;
1414                         s->last_mv[1][i][1]= (s->mv[1][i][1] = my)*2;
1415                     }
1416                 }
1417             }
1418         }
1419
1420         if(IS_DIRECT(mb_type)){
1421             if(IS_SKIP(mb_type))
1422                 mx=my=0;
1423             else{
1424                 mx = h263_decode_motion(s, 0, 1);
1425                 my = h263_decode_motion(s, 0, 1);
1426             }
1427
1428             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1429             mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
1430         }
1431         s->current_picture.f.mb_type[xy] = mb_type;
1432     } else { /* I-Frame */
1433         do{
1434             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1435             if (cbpc < 0){
1436                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1437                 return -1;
1438             }
1439         }while(cbpc == 8);
1440
1441         dquant = cbpc & 4;
1442         s->mb_intra = 1;
1443 intra:
1444         s->ac_pred = get_bits1(&s->gb);
1445         if(s->ac_pred)
1446             s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1447         else
1448             s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
1449
1450         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1451         if(cbpy<0){
1452             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1453             return -1;
1454         }
1455         cbp = (cbpc & 3) | (cbpy << 2);
1456
1457         s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1458
1459         if (dquant) {
1460             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1461         }
1462
1463         if(!s->progressive_sequence)
1464             s->interlaced_dct= get_bits1(&s->gb);
1465
1466         s->dsp.clear_blocks(s->block[0]);
1467         /* decode each block */
1468         for (i = 0; i < 6; i++) {
1469             if (mpeg4_decode_block(s, block[i], i, cbp&32, 1, 0) < 0)
1470                 return -1;
1471             cbp+=cbp;
1472         }
1473         goto end;
1474     }
1475
1476     /* decode each block */
1477     for (i = 0; i < 6; i++) {
1478         if (mpeg4_decode_block(s, block[i], i, cbp&32, 0, 0) < 0)
1479             return -1;
1480         cbp+=cbp;
1481     }
1482 end:
1483
1484         /* per-MB end of slice check */
1485     if(s->codec_id==CODEC_ID_MPEG4){
1486         int next= mpeg4_is_resync(s);
1487         if(next) {
1488             if        (s->mb_x + s->mb_y*s->mb_width + 1 >  next && s->avctx->error_recognition >= FF_ER_AGGRESSIVE) {
1489                 return -1;
1490             } else if (s->mb_x + s->mb_y*s->mb_width + 1 >= next)
1491                 return SLICE_END;
1492         }
1493     }
1494
1495     return SLICE_OK;
1496 }
1497
1498
1499 static int mpeg4_decode_gop_header(MpegEncContext * s, GetBitContext *gb){
1500     int hours, minutes, seconds;
1501
1502     if(!show_bits(gb, 23)){
1503         av_log(s->avctx, AV_LOG_WARNING, "GOP header invalid\n");
1504         return -1;
1505     }
1506
1507     hours= get_bits(gb, 5);
1508     minutes= get_bits(gb, 6);
1509     skip_bits1(gb);
1510     seconds= get_bits(gb, 6);
1511
1512     s->time_base= seconds + 60*(minutes + 60*hours);
1513
1514     skip_bits1(gb);
1515     skip_bits1(gb);
1516
1517     return 0;
1518 }
1519
1520 static int mpeg4_decode_profile_level(MpegEncContext * s, GetBitContext *gb){
1521
1522     s->avctx->profile = get_bits(gb, 4);
1523     s->avctx->level   = get_bits(gb, 4);
1524
1525     // for Simple profile, level 0
1526     if (s->avctx->profile == 0 && s->avctx->level == 8) {
1527         s->avctx->level = 0;
1528     }
1529
1530     return 0;
1531 }
1532
1533 static int decode_vol_header(MpegEncContext *s, GetBitContext *gb){
1534     int width, height, vo_ver_id;
1535
1536     /* vol header */
1537     skip_bits(gb, 1); /* random access */
1538     s->vo_type= get_bits(gb, 8);
1539     if (get_bits1(gb) != 0) { /* is_ol_id */
1540         vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
1541         skip_bits(gb, 3); /* vo_priority */
1542     } else {
1543         vo_ver_id = 1;
1544     }
1545     s->aspect_ratio_info= get_bits(gb, 4);
1546     if(s->aspect_ratio_info == FF_ASPECT_EXTENDED){
1547         s->avctx->sample_aspect_ratio.num= get_bits(gb, 8); // par_width
1548         s->avctx->sample_aspect_ratio.den= get_bits(gb, 8); // par_height
1549     }else{
1550         s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1551     }
1552
1553     if ((s->vol_control_parameters=get_bits1(gb))) { /* vol control parameter */
1554         int chroma_format= get_bits(gb, 2);
1555         if(chroma_format!=CHROMA_420){
1556             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
1557         }
1558         s->low_delay= get_bits1(gb);
1559         if(get_bits1(gb)){ /* vbv parameters */
1560             get_bits(gb, 15);   /* first_half_bitrate */
1561             skip_bits1(gb);     /* marker */
1562             get_bits(gb, 15);   /* latter_half_bitrate */
1563             skip_bits1(gb);     /* marker */
1564             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
1565             skip_bits1(gb);     /* marker */
1566             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
1567             get_bits(gb, 11);   /* first_half_vbv_occupancy */
1568             skip_bits1(gb);     /* marker */
1569             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
1570             skip_bits1(gb);     /* marker */
1571         }
1572     }else{
1573         // set low delay flag only once the smartest? low delay detection won't be overriden
1574         if(s->picture_number==0)
1575             s->low_delay=0;
1576     }
1577
1578     s->shape = get_bits(gb, 2); /* vol shape */
1579     if(s->shape != RECT_SHAPE) av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
1580     if(s->shape == GRAY_SHAPE && vo_ver_id != 1){
1581         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
1582         skip_bits(gb, 4);  //video_object_layer_shape_extension
1583     }
1584
1585     check_marker(gb, "before time_increment_resolution");
1586
1587     s->avctx->time_base.den = get_bits(gb, 16);
1588     if(!s->avctx->time_base.den){
1589         av_log(s->avctx, AV_LOG_ERROR, "time_base.den==0\n");
1590         s->avctx->time_base.num = 0;
1591         return -1;
1592     }
1593
1594     s->time_increment_bits = av_log2(s->avctx->time_base.den - 1) + 1;
1595     if (s->time_increment_bits < 1)
1596         s->time_increment_bits = 1;
1597
1598     check_marker(gb, "before fixed_vop_rate");
1599
1600     if (get_bits1(gb) != 0) {   /* fixed_vop_rate  */
1601         s->avctx->time_base.num = get_bits(gb, s->time_increment_bits);
1602     }else
1603         s->avctx->time_base.num = 1;
1604
1605     s->t_frame=0;
1606
1607     if (s->shape != BIN_ONLY_SHAPE) {
1608         if (s->shape == RECT_SHAPE) {
1609             skip_bits1(gb);   /* marker */
1610             width = get_bits(gb, 13);
1611             skip_bits1(gb);   /* marker */
1612             height = get_bits(gb, 13);
1613             skip_bits1(gb);   /* marker */
1614             if(width && height && !(s->width && s->codec_tag == AV_RL32("MP4S"))){ /* they should be non zero but who knows ... */
1615                 s->width = width;
1616                 s->height = height;
1617             }
1618         }
1619
1620         s->progressive_sequence=
1621         s->progressive_frame= get_bits1(gb)^1;
1622         s->interlaced_dct=0;
1623         if(!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
1624             av_log(s->avctx, AV_LOG_INFO, "MPEG4 OBMC not supported (very likely buggy encoder)\n");   /* OBMC Disable */
1625         if (vo_ver_id == 1) {
1626             s->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
1627         } else {
1628             s->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
1629         }
1630         if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
1631         if(s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE){
1632             if(s->vol_sprite_usage==STATIC_SPRITE){
1633                 s->sprite_width = get_bits(gb, 13);
1634                 skip_bits1(gb); /* marker */
1635                 s->sprite_height= get_bits(gb, 13);
1636                 skip_bits1(gb); /* marker */
1637                 s->sprite_left  = get_bits(gb, 13);
1638                 skip_bits1(gb); /* marker */
1639                 s->sprite_top   = get_bits(gb, 13);
1640                 skip_bits1(gb); /* marker */
1641             }
1642             s->num_sprite_warping_points= get_bits(gb, 6);
1643             if(s->num_sprite_warping_points > 3){
1644                 av_log(s->avctx, AV_LOG_ERROR, "%d sprite_warping_points\n", s->num_sprite_warping_points);
1645                 s->num_sprite_warping_points= 0;
1646                 return -1;
1647             }
1648             s->sprite_warping_accuracy = get_bits(gb, 2);
1649             s->sprite_brightness_change= get_bits1(gb);
1650             if(s->vol_sprite_usage==STATIC_SPRITE)
1651                 s->low_latency_sprite= get_bits1(gb);
1652         }
1653         // FIXME sadct disable bit if verid!=1 && shape not rect
1654
1655         if (get_bits1(gb) == 1) {   /* not_8_bit */
1656             s->quant_precision = get_bits(gb, 4); /* quant_precision */
1657             if(get_bits(gb, 4)!=8) av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n"); /* bits_per_pixel */
1658             if(s->quant_precision!=5) av_log(s->avctx, AV_LOG_ERROR, "quant precision %d\n", s->quant_precision);
1659         } else {
1660             s->quant_precision = 5;
1661         }
1662
1663         // FIXME a bunch of grayscale shape things
1664
1665         if((s->mpeg_quant=get_bits1(gb))){ /* vol_quant_type */
1666             int i, v;
1667
1668             /* load default matrixes */
1669             for(i=0; i<64; i++){
1670                 int j= s->dsp.idct_permutation[i];
1671                 v= ff_mpeg4_default_intra_matrix[i];
1672                 s->intra_matrix[j]= v;
1673                 s->chroma_intra_matrix[j]= v;
1674
1675                 v= ff_mpeg4_default_non_intra_matrix[i];
1676                 s->inter_matrix[j]= v;
1677                 s->chroma_inter_matrix[j]= v;
1678             }
1679
1680             /* load custom intra matrix */
1681             if(get_bits1(gb)){
1682                 int last=0;
1683                 for(i=0; i<64; i++){
1684                     int j;
1685                     v= get_bits(gb, 8);
1686                     if(v==0) break;
1687
1688                     last= v;
1689                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1690                     s->intra_matrix[j]= v;
1691                     s->chroma_intra_matrix[j]= v;
1692                 }
1693
1694                 /* replicate last value */
1695                 for(; i<64; i++){
1696                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1697                     s->intra_matrix[j]= last;
1698                     s->chroma_intra_matrix[j]= last;
1699                 }
1700             }
1701
1702             /* load custom non intra matrix */
1703             if(get_bits1(gb)){
1704                 int last=0;
1705                 for(i=0; i<64; i++){
1706                     int j;
1707                     v= get_bits(gb, 8);
1708                     if(v==0) break;
1709
1710                     last= v;
1711                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1712                     s->inter_matrix[j]= v;
1713                     s->chroma_inter_matrix[j]= v;
1714                 }
1715
1716                 /* replicate last value */
1717                 for(; i<64; i++){
1718                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1719                     s->inter_matrix[j]= last;
1720                     s->chroma_inter_matrix[j]= last;
1721                 }
1722             }
1723
1724             // FIXME a bunch of grayscale shape things
1725         }
1726
1727         if(vo_ver_id != 1)
1728              s->quarter_sample= get_bits1(gb);
1729         else s->quarter_sample=0;
1730
1731         if(!get_bits1(gb)){
1732             int pos= get_bits_count(gb);
1733             int estimation_method= get_bits(gb, 2);
1734             if(estimation_method<2){
1735                 if(!get_bits1(gb)){
1736                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //opaque
1737                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //transparent
1738                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_cae
1739                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //inter_cae
1740                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //no_update
1741                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //upampling
1742                 }
1743                 if(!get_bits1(gb)){
1744                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_blocks
1745                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter_blocks
1746                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter4v_blocks
1747                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //not coded blocks
1748                 }
1749                 if(!check_marker(gb, "in complexity estimation part 1")){
1750                     skip_bits_long(gb, pos - get_bits_count(gb));
1751                     goto no_cplx_est;
1752                 }
1753                 if(!get_bits1(gb)){
1754                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_coeffs
1755                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_lines
1756                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //vlc_syms
1757                     s->cplx_estimation_trash_i += 4*get_bits1(gb); //vlc_bits
1758                 }
1759                 if(!get_bits1(gb)){
1760                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //apm
1761                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //npm
1762                     s->cplx_estimation_trash_b += 8*get_bits1(gb); //interpolate_mc_q
1763                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //forwback_mc_q
1764                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel2
1765                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel4
1766                 }
1767                 if(!check_marker(gb, "in complexity estimation part 2")){
1768                     skip_bits_long(gb, pos - get_bits_count(gb));
1769                     goto no_cplx_est;
1770                 }
1771                 if(estimation_method==1){
1772                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //sadct
1773                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //qpel
1774                 }
1775             }else
1776                 av_log(s->avctx, AV_LOG_ERROR, "Invalid Complexity estimation method %d\n", estimation_method);
1777         }else{
1778 no_cplx_est:
1779             s->cplx_estimation_trash_i=
1780             s->cplx_estimation_trash_p=
1781             s->cplx_estimation_trash_b= 0;
1782         }
1783
1784         s->resync_marker= !get_bits1(gb); /* resync_marker_disabled */
1785
1786         s->data_partitioning= get_bits1(gb);
1787         if(s->data_partitioning){
1788             s->rvlc= get_bits1(gb);
1789         }
1790
1791         if(vo_ver_id != 1) {
1792             s->new_pred= get_bits1(gb);
1793             if(s->new_pred){
1794                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
1795                 skip_bits(gb, 2); /* requested upstream message type */
1796                 skip_bits1(gb); /* newpred segment type */
1797             }
1798             s->reduced_res_vop= get_bits1(gb);
1799             if(s->reduced_res_vop) av_log(s->avctx, AV_LOG_ERROR, "reduced resolution VOP not supported\n");
1800         }
1801         else{
1802             s->new_pred=0;
1803             s->reduced_res_vop= 0;
1804         }
1805
1806         s->scalability= get_bits1(gb);
1807
1808         if (s->scalability) {
1809             GetBitContext bak= *gb;
1810             int h_sampling_factor_n;
1811             int h_sampling_factor_m;
1812             int v_sampling_factor_n;
1813             int v_sampling_factor_m;
1814
1815             s->hierachy_type= get_bits1(gb);
1816             skip_bits(gb, 4);  /* ref_layer_id */
1817             skip_bits1(gb);    /* ref_layer_sampling_dir */
1818             h_sampling_factor_n= get_bits(gb, 5);
1819             h_sampling_factor_m= get_bits(gb, 5);
1820             v_sampling_factor_n= get_bits(gb, 5);
1821             v_sampling_factor_m= get_bits(gb, 5);
1822             s->enhancement_type= get_bits1(gb);
1823
1824             if(   h_sampling_factor_n==0 || h_sampling_factor_m==0
1825                || v_sampling_factor_n==0 || v_sampling_factor_m==0){
1826                 /* illegal scalability header (VERY broken encoder),
1827                  * trying to workaround */
1828                 s->scalability=0;
1829                 *gb= bak;
1830             }else
1831                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
1832
1833             // bin shape stuff FIXME
1834         }
1835     }
1836     return 0;
1837 }
1838
1839 /**
1840  * decodes the user data stuff in the header.
1841  * Also initializes divx/xvid/lavc_version/build.
1842  */
1843 static int decode_user_data(MpegEncContext *s, GetBitContext *gb){
1844     char buf[256];
1845     int i;
1846     int e;
1847     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
1848     char last;
1849
1850     for(i=0; i<255 && get_bits_count(gb) < gb->size_in_bits; i++){
1851         if(show_bits(gb, 23) == 0) break;
1852         buf[i]= get_bits(gb, 8);
1853     }
1854     buf[i]=0;
1855
1856     /* divx detection */
1857     e=sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
1858     if(e<2)
1859         e=sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
1860     if(e>=2){
1861         s->divx_version= ver;
1862         s->divx_build= build;
1863         s->divx_packed= e==3 && last=='p';
1864         if(s->divx_packed && !s->showed_packed_warning) {
1865             av_log(s->avctx, AV_LOG_WARNING, "Invalid and inefficient vfw-avi packed B frames detected\n");
1866             s->showed_packed_warning=1;
1867         }
1868     }
1869
1870     /* ffmpeg detection */
1871     e=sscanf(buf, "FFmpe%*[^b]b%d", &build)+3;
1872     if(e!=4)
1873         e=sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
1874     if(e!=4){
1875         e=sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3)+1;
1876         if (e>1)
1877             build= (ver<<16) + (ver2<<8) + ver3;
1878     }
1879     if(e!=4){
1880         if(strcmp(buf, "ffmpeg")==0){
1881             s->lavc_build= 4600;
1882         }
1883     }
1884     if(e==4){
1885         s->lavc_build= build;
1886     }
1887
1888     /* Xvid detection */
1889     e=sscanf(buf, "XviD%d", &build);
1890     if(e==1){
1891         s->xvid_build= build;
1892     }
1893
1894     return 0;
1895 }
1896
1897 static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
1898     int time_incr, time_increment;
1899
1900     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I;        /* pict type: I = 0 , P = 1 */
1901     if(s->pict_type==AV_PICTURE_TYPE_B && s->low_delay && s->vol_control_parameters==0 && !(s->flags & CODEC_FLAG_LOW_DELAY)){
1902         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag incorrectly, clearing it\n");
1903         s->low_delay=0;
1904     }
1905
1906     s->partitioned_frame= s->data_partitioning && s->pict_type!=AV_PICTURE_TYPE_B;
1907     if(s->partitioned_frame)
1908         s->decode_mb= mpeg4_decode_partitioned_mb;
1909     else
1910         s->decode_mb= mpeg4_decode_mb;
1911
1912     time_incr=0;
1913     while (get_bits1(gb) != 0)
1914         time_incr++;
1915
1916     check_marker(gb, "before time_increment");
1917
1918     if(s->time_increment_bits==0 || !(show_bits(gb, s->time_increment_bits+1)&1)){
1919         av_log(s->avctx, AV_LOG_ERROR, "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
1920
1921         for(s->time_increment_bits=1 ;s->time_increment_bits<16; s->time_increment_bits++){
1922             if (    s->pict_type == AV_PICTURE_TYPE_P
1923                 || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE)) {
1924                 if((show_bits(gb, s->time_increment_bits+6)&0x37) == 0x30) break;
1925             }else
1926                 if((show_bits(gb, s->time_increment_bits+5)&0x1F) == 0x18) break;
1927         }
1928
1929         av_log(s->avctx, AV_LOG_ERROR, "my guess is %d bits ;)\n",s->time_increment_bits);
1930     }
1931
1932     if(IS_3IV1) time_increment= get_bits1(gb); //FIXME investigate further
1933     else time_increment= get_bits(gb, s->time_increment_bits);
1934
1935     if(s->pict_type!=AV_PICTURE_TYPE_B){
1936         s->last_time_base= s->time_base;
1937         s->time_base+= time_incr;
1938         s->time= s->time_base*s->avctx->time_base.den + time_increment;
1939         if(s->workaround_bugs&FF_BUG_UMP4){
1940             if(s->time < s->last_non_b_time){
1941                 /* header is not mpeg-4-compatible, broken encoder,
1942                  * trying to workaround */
1943                 s->time_base++;
1944                 s->time+= s->avctx->time_base.den;
1945             }
1946         }
1947         s->pp_time= s->time - s->last_non_b_time;
1948         s->last_non_b_time= s->time;
1949     }else{
1950         s->time= (s->last_time_base + time_incr)*s->avctx->time_base.den + time_increment;
1951         s->pb_time= s->pp_time - (s->last_non_b_time - s->time);
1952         if(s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0){
1953             /* messed up order, maybe after seeking? skipping current b-frame */
1954             return FRAME_SKIPPED;
1955         }
1956         ff_mpeg4_init_direct_mv(s);
1957
1958         if(s->t_frame==0) s->t_frame= s->pb_time;
1959         if(s->t_frame==0) s->t_frame=1; // 1/0 protection
1960         s->pp_field_time= (  ROUNDED_DIV(s->last_non_b_time, s->t_frame)
1961                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
1962         s->pb_field_time= (  ROUNDED_DIV(s->time, s->t_frame)
1963                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
1964         if(!s->progressive_sequence){
1965             if(s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1)
1966                 return FRAME_SKIPPED;
1967         }
1968     }
1969
1970     if(s->avctx->time_base.num)
1971         s->current_picture_ptr->f.pts = (s->time + s->avctx->time_base.num / 2) / s->avctx->time_base.num;
1972     else
1973         s->current_picture_ptr->f.pts = AV_NOPTS_VALUE;
1974     if(s->avctx->debug&FF_DEBUG_PTS)
1975         av_log(s->avctx, AV_LOG_DEBUG, "MPEG4 PTS: %"PRId64"\n",
1976                s->current_picture_ptr->f.pts);
1977
1978     check_marker(gb, "before vop_coded");
1979
1980     /* vop coded */
1981     if (get_bits1(gb) != 1){
1982         if(s->avctx->debug&FF_DEBUG_PICT_INFO)
1983             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
1984         return FRAME_SKIPPED;
1985     }
1986     if (s->shape != BIN_ONLY_SHAPE && ( s->pict_type == AV_PICTURE_TYPE_P
1987                           || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE))) {
1988         /* rounding type for motion estimation */
1989         s->no_rounding = get_bits1(gb);
1990     } else {
1991         s->no_rounding = 0;
1992     }
1993 //FIXME reduced res stuff
1994
1995      if (s->shape != RECT_SHAPE) {
1996          if (s->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
1997              skip_bits(gb, 13); /* width */
1998              skip_bits1(gb);   /* marker */
1999              skip_bits(gb, 13); /* height */
2000              skip_bits1(gb);   /* marker */
2001              skip_bits(gb, 13); /* hor_spat_ref */
2002              skip_bits1(gb);   /* marker */
2003              skip_bits(gb, 13); /* ver_spat_ref */
2004          }
2005          skip_bits1(gb); /* change_CR_disable */
2006
2007          if (get_bits1(gb) != 0) {
2008              skip_bits(gb, 8); /* constant_alpha_value */
2009          }
2010      }
2011 //FIXME complexity estimation stuff
2012
2013      if (s->shape != BIN_ONLY_SHAPE) {
2014          skip_bits_long(gb, s->cplx_estimation_trash_i);
2015          if(s->pict_type != AV_PICTURE_TYPE_I)
2016             skip_bits_long(gb, s->cplx_estimation_trash_p);
2017          if(s->pict_type == AV_PICTURE_TYPE_B)
2018             skip_bits_long(gb, s->cplx_estimation_trash_b);
2019
2020          s->intra_dc_threshold= mpeg4_dc_threshold[ get_bits(gb, 3) ];
2021          if(!s->progressive_sequence){
2022              s->top_field_first= get_bits1(gb);
2023              s->alternate_scan= get_bits1(gb);
2024          }else
2025              s->alternate_scan= 0;
2026      }
2027
2028      if(s->alternate_scan){
2029          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
2030          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
2031          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2032          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2033      } else{
2034          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
2035          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
2036          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2037          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2038      }
2039
2040      if(s->pict_type == AV_PICTURE_TYPE_S && (s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE)){
2041          mpeg4_decode_sprite_trajectory(s, gb);
2042          if(s->sprite_brightness_change) av_log(s->avctx, AV_LOG_ERROR, "sprite_brightness_change not supported\n");
2043          if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2044      }
2045
2046      if (s->shape != BIN_ONLY_SHAPE) {
2047          s->chroma_qscale= s->qscale = get_bits(gb, s->quant_precision);
2048          if(s->qscale==0){
2049              av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (qscale=0)\n");
2050              return -1; // makes no sense to continue, as there is nothing left from the image then
2051          }
2052
2053          if (s->pict_type != AV_PICTURE_TYPE_I) {
2054              s->f_code = get_bits(gb, 3);       /* fcode_for */
2055              if(s->f_code==0){
2056                  av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (f_code=0)\n");
2057                  return -1; // makes no sense to continue, as the MV decoding will break very quickly
2058              }
2059          }else
2060              s->f_code=1;
2061
2062          if (s->pict_type == AV_PICTURE_TYPE_B) {
2063              s->b_code = get_bits(gb, 3);
2064          }else
2065              s->b_code=1;
2066
2067          if(s->avctx->debug&FF_DEBUG_PICT_INFO){
2068              av_log(s->avctx, AV_LOG_DEBUG, "qp:%d fc:%d,%d %s size:%d pro:%d alt:%d top:%d %spel part:%d resync:%d w:%d a:%d rnd:%d vot:%d%s dc:%d ce:%d/%d/%d\n",
2069                  s->qscale, s->f_code, s->b_code,
2070                  s->pict_type == AV_PICTURE_TYPE_I ? "I" : (s->pict_type == AV_PICTURE_TYPE_P ? "P" : (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
2071                  gb->size_in_bits,s->progressive_sequence, s->alternate_scan, s->top_field_first,
2072                  s->quarter_sample ? "q" : "h", s->data_partitioning, s->resync_marker, s->num_sprite_warping_points,
2073                  s->sprite_warping_accuracy, 1-s->no_rounding, s->vo_type, s->vol_control_parameters ? " VOLC" : " ", s->intra_dc_threshold, s->cplx_estimation_trash_i, s->cplx_estimation_trash_p, s->cplx_estimation_trash_b);
2074          }
2075
2076          if(!s->scalability){
2077              if (s->shape!=RECT_SHAPE && s->pict_type!=AV_PICTURE_TYPE_I) {
2078                  skip_bits1(gb); // vop shape coding type
2079              }
2080          }else{
2081              if(s->enhancement_type){
2082                  int load_backward_shape= get_bits1(gb);
2083                  if(load_backward_shape){
2084                      av_log(s->avctx, AV_LOG_ERROR, "load backward shape isn't supported\n");
2085                  }
2086              }
2087              skip_bits(gb, 2); //ref_select_code
2088          }
2089      }
2090      /* detect buggy encoders which don't set the low_delay flag (divx4/xvid/opendivx)*/
2091      // note we cannot detect divx5 without b-frames easily (although it's buggy too)
2092      if(s->vo_type==0 && s->vol_control_parameters==0 && s->divx_version==-1 && s->picture_number==0){
2093          av_log(s->avctx, AV_LOG_WARNING, "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2094          s->low_delay=1;
2095      }
2096
2097      s->picture_number++; // better than pic number==0 always ;)
2098
2099      s->y_dc_scale_table= ff_mpeg4_y_dc_scale_table; //FIXME add short header support
2100      s->c_dc_scale_table= ff_mpeg4_c_dc_scale_table;
2101
2102      if(s->workaround_bugs&FF_BUG_EDGE){
2103          s->h_edge_pos= s->width;
2104          s->v_edge_pos= s->height;
2105      }
2106      return 0;
2107 }
2108
2109 /**
2110  * decode mpeg4 headers
2111  * @return <0 if no VOP found (or a damaged one)
2112  *         FRAME_SKIPPED if a not coded VOP is found
2113  *         0 if a VOP is found
2114  */
2115 int ff_mpeg4_decode_picture_header(MpegEncContext * s, GetBitContext *gb)
2116 {
2117     int startcode, v;
2118
2119     /* search next start code */
2120     align_get_bits(gb);
2121
2122     if(s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630){
2123         skip_bits(gb, 24);
2124         if(get_bits(gb, 8) == 0xF0)
2125             goto end;
2126     }
2127
2128     startcode = 0xff;
2129     for(;;) {
2130         if(get_bits_count(gb) >= gb->size_in_bits){
2131             if(gb->size_in_bits==8 && (s->divx_version>=0 || s->xvid_build>=0)){
2132                 av_log(s->avctx, AV_LOG_WARNING, "frame skip %d\n", gb->size_in_bits);
2133                 return FRAME_SKIPPED; //divx bug
2134             }else
2135                 return -1; //end of stream
2136         }
2137
2138         /* use the bits after the test */
2139         v = get_bits(gb, 8);
2140         startcode = ((startcode << 8) | v) & 0xffffffff;
2141
2142         if((startcode&0xFFFFFF00) != 0x100)
2143             continue; //no startcode
2144
2145         if(s->avctx->debug&FF_DEBUG_STARTCODE){
2146             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
2147             if     (startcode<=0x11F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
2148             else if(startcode<=0x12F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
2149             else if(startcode<=0x13F) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2150             else if(startcode<=0x15F) av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
2151             else if(startcode<=0x1AF) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2152             else if(startcode==0x1B0) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
2153             else if(startcode==0x1B1) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
2154             else if(startcode==0x1B2) av_log(s->avctx, AV_LOG_DEBUG, "User Data");
2155             else if(startcode==0x1B3) av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
2156             else if(startcode==0x1B4) av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
2157             else if(startcode==0x1B5) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
2158             else if(startcode==0x1B6) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
2159             else if(startcode==0x1B7) av_log(s->avctx, AV_LOG_DEBUG, "slice start");
2160             else if(startcode==0x1B8) av_log(s->avctx, AV_LOG_DEBUG, "extension start");
2161             else if(startcode==0x1B9) av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
2162             else if(startcode==0x1BA) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
2163             else if(startcode==0x1BB) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
2164             else if(startcode==0x1BC) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
2165             else if(startcode==0x1BD) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
2166             else if(startcode==0x1BE) av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
2167             else if(startcode==0x1BF) av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
2168             else if(startcode==0x1C0) av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
2169             else if(startcode==0x1C1) av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
2170             else if(startcode==0x1C2) av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
2171             else if(startcode==0x1C3) av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
2172             else if(startcode<=0x1C5) av_log(s->avctx, AV_LOG_DEBUG, "reserved");
2173             else if(startcode<=0x1FF) av_log(s->avctx, AV_LOG_DEBUG, "System start");
2174             av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
2175         }
2176
2177         if(startcode >= 0x120 && startcode <= 0x12F){
2178             if(decode_vol_header(s, gb) < 0)
2179                 return -1;
2180         }
2181         else if(startcode == USER_DATA_STARTCODE){
2182             decode_user_data(s, gb);
2183         }
2184         else if(startcode == GOP_STARTCODE){
2185             mpeg4_decode_gop_header(s, gb);
2186         }
2187         else if(startcode == VOS_STARTCODE){
2188             mpeg4_decode_profile_level(s, gb);
2189         }
2190         else if(startcode == VOP_STARTCODE){
2191             break;
2192         }
2193
2194         align_get_bits(gb);
2195         startcode = 0xff;
2196     }
2197 end:
2198     if(s->flags& CODEC_FLAG_LOW_DELAY)
2199         s->low_delay=1;
2200     s->avctx->has_b_frames= !s->low_delay;
2201     return decode_vop_header(s, gb);
2202 }
2203
2204 static av_cold int decode_init(AVCodecContext *avctx)
2205 {
2206     MpegEncContext *s = avctx->priv_data;
2207     int ret;
2208     static int done = 0;
2209
2210     s->divx_version=
2211     s->divx_build=
2212     s->xvid_build=
2213     s->lavc_build= -1;
2214
2215     if((ret=ff_h263_decode_init(avctx)) < 0)
2216         return ret;
2217
2218     if (!done) {
2219         done = 1;
2220
2221         init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
2222         init_rl(&rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
2223         init_rl(&rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
2224         INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
2225         INIT_VLC_RL(rvlc_rl_inter, 1072);
2226         INIT_VLC_RL(rvlc_rl_intra, 1072);
2227         INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
2228                  &ff_mpeg4_DCtab_lum[0][1], 2, 1,
2229                  &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
2230         INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
2231                  &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
2232                  &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
2233         INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
2234                  &sprite_trajectory_tab[0][1], 4, 2,
2235                  &sprite_trajectory_tab[0][0], 4, 2, 128);
2236         INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
2237                  &mb_type_b_tab[0][1], 2, 1,
2238                  &mb_type_b_tab[0][0], 2, 1, 16);
2239     }
2240
2241     s->h263_pred = 1;
2242     s->low_delay = 0; //default, might be overriden in the vol header during header parsing
2243     s->decode_mb= mpeg4_decode_mb;
2244     s->time_increment_bits = 4; /* default value for broken headers */
2245     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
2246
2247     return 0;
2248 }
2249
2250 static const AVProfile mpeg4_video_profiles[] = {
2251     { FF_PROFILE_MPEG4_SIMPLE,                    "Simple Profile" },
2252     { FF_PROFILE_MPEG4_SIMPLE_SCALABLE,           "Simple Scalable Profile" },
2253     { FF_PROFILE_MPEG4_CORE,                      "Core Profile" },
2254     { FF_PROFILE_MPEG4_MAIN,                      "Main Profile" },
2255     { FF_PROFILE_MPEG4_N_BIT,                     "N-bit Profile" },
2256     { FF_PROFILE_MPEG4_SCALABLE_TEXTURE,          "Scalable Texture Profile" },
2257     { FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION,     "Simple Face Animation Profile" },
2258     { FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE,    "Basic Animated Texture Profile" },
2259     { FF_PROFILE_MPEG4_HYBRID,                    "Hybrid Profile" },
2260     { FF_PROFILE_MPEG4_ADVANCED_REAL_TIME,        "Advanced Real Time Simple Profile" },
2261     { FF_PROFILE_MPEG4_CORE_SCALABLE,             "Code Scalable Profile" },
2262     { FF_PROFILE_MPEG4_ADVANCED_CODING,           "Advanced Coding Profile" },
2263     { FF_PROFILE_MPEG4_ADVANCED_CORE,             "Advanced Core Profile" },
2264     { FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE, "Advanced Scalable Texture Profile" },
2265     { FF_PROFILE_MPEG4_SIMPLE_STUDIO,             "Simple Studio Profile" },
2266     { FF_PROFILE_MPEG4_ADVANCED_SIMPLE,           "Advanced Simple Profile" },
2267 };
2268
2269 AVCodec ff_mpeg4_decoder = {
2270     .name           = "mpeg4",
2271     .type           = AVMEDIA_TYPE_VIDEO,
2272     .id             = CODEC_ID_MPEG4,
2273     .priv_data_size = sizeof(MpegEncContext),
2274     .init           = decode_init,
2275     .close          = ff_h263_decode_end,
2276     .decode         = ff_h263_decode_frame,
2277     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_FRAME_THREADS,
2278     .flush= ff_mpeg_flush,
2279     .max_lowres= 3,
2280     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
2281     .pix_fmts= ff_hwaccel_pixfmt_list_420,
2282     .profiles = NULL_IF_CONFIG_SMALL(mpeg4_video_profiles),
2283     .update_thread_context= ONLY_IF_THREADS_ENABLED(ff_mpeg_update_thread_context)
2284 };
2285
2286
2287 #if CONFIG_MPEG4_VDPAU_DECODER
2288 AVCodec ff_mpeg4_vdpau_decoder = {
2289     .name           = "mpeg4_vdpau",
2290     .type           = AVMEDIA_TYPE_VIDEO,
2291     .id             = CODEC_ID_MPEG4,
2292     .priv_data_size = sizeof(MpegEncContext),
2293     .init           = decode_init,
2294     .close          = ff_h263_decode_end,
2295     .decode         = ff_h263_decode_frame,
2296     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_HWACCEL_VDPAU,
2297     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 (VDPAU)"),
2298     .pix_fmts= (const enum PixelFormat[]){PIX_FMT_VDPAU_MPEG4, PIX_FMT_NONE},
2299 };
2300 #endif