disable encoders where appropriate (patch courtesy of BERO
[ffmpeg.git] / libavcodec / mpeg12.c
1 /*
2  * MPEG1 codec / MPEG2 decoder
3  * Copyright (c) 2000,2001 Fabrice Bellard.
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this library; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  */
19  
20 /**
21  * @file mpeg12.c
22  * MPEG1/2 codec
23  */
24  
25 //#define DEBUG
26 #include "avcodec.h"
27 #include "dsputil.h"
28 #include "mpegvideo.h"
29
30 #include "mpeg12data.h"
31
32
33 /* Start codes. */
34 #define SEQ_END_CODE            0x000001b7
35 #define SEQ_START_CODE          0x000001b3
36 #define GOP_START_CODE          0x000001b8
37 #define PICTURE_START_CODE      0x00000100
38 #define SLICE_MIN_START_CODE    0x00000101
39 #define SLICE_MAX_START_CODE    0x000001af
40 #define EXT_START_CODE          0x000001b5
41 #define USER_START_CODE         0x000001b2
42
43 #define DC_VLC_BITS 9
44 #define MV_VLC_BITS 9
45 #define MBINCR_VLC_BITS 9
46 #define MB_PAT_VLC_BITS 9
47 #define MB_PTYPE_VLC_BITS 6
48 #define MB_BTYPE_VLC_BITS 6
49 #define TEX_VLC_BITS 9
50
51 #ifdef CONFIG_ENCODERS
52 static void mpeg1_encode_block(MpegEncContext *s, 
53                          DCTELEM *block, 
54                          int component);
55 static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code);    // RAL: f_code parameter added
56 #endif //CONFIG_ENCODERS
57 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
58 static inline int mpeg1_decode_block_inter(MpegEncContext *s, 
59                               DCTELEM *block, 
60                               int n);
61 static inline int mpeg1_decode_block_intra(MpegEncContext *s, 
62                               DCTELEM *block, 
63                               int n);
64 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s, 
65                                         DCTELEM *block, 
66                                         int n);
67 static inline int mpeg2_decode_block_intra(MpegEncContext *s, 
68                                     DCTELEM *block, 
69                                     int n);
70 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
71
72 #ifdef HAVE_XVMC
73 extern int XVMC_field_start(MpegEncContext *s, AVCodecContext *avctx);
74 extern int XVMC_field_end(MpegEncContext *s);
75 #endif
76
77 #ifdef CONFIG_ENCODERS
78 static uint8_t (*mv_penalty)[MAX_MV*2+1]= NULL;
79 static uint8_t fcode_tab[MAX_MV*2+1];
80
81 static uint32_t uni_mpeg1_ac_vlc_bits[64*64*2];
82 static uint8_t  uni_mpeg1_ac_vlc_len [64*64*2];
83
84 /* simple include everything table for dc, first byte is bits number next 3 are code*/
85 static uint32_t mpeg1_lum_dc_uni[512];
86 static uint32_t mpeg1_chr_dc_uni[512];
87
88 static uint8_t mpeg1_index_run[2][64];
89 static int8_t mpeg1_max_level[2][64];
90 #endif //CONFIG_ENCODERS
91
92 static void init_2d_vlc_rl(RLTable *rl)
93 {
94     int i;
95     
96     init_vlc(&rl->vlc, TEX_VLC_BITS, rl->n + 2, 
97              &rl->table_vlc[0][1], 4, 2,
98              &rl->table_vlc[0][0], 4, 2);
99
100     
101     rl->rl_vlc[0]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
102     for(i=0; i<rl->vlc.table_size; i++){
103         int code= rl->vlc.table[i][0];
104         int len = rl->vlc.table[i][1];
105         int level, run;
106     
107         if(len==0){ // illegal code
108             run= 65;
109             level= MAX_LEVEL;
110         }else if(len<0){ //more bits needed
111             run= 0;
112             level= code;
113         }else{
114             if(code==rl->n){ //esc
115                 run= 65;
116                 level= 0;
117             }else if(code==rl->n+1){ //eob
118                 run= 0;
119                 level= 127;
120             }else{
121                 run=   rl->table_run  [code] + 1;
122                 level= rl->table_level[code];
123             }
124         }
125         rl->rl_vlc[0][i].len= len;
126         rl->rl_vlc[0][i].level= level;
127         rl->rl_vlc[0][i].run= run;
128     }
129 }
130
131 #ifdef CONFIG_ENCODERS
132 static void init_uni_ac_vlc(RLTable *rl, uint32_t *uni_ac_vlc_bits, uint8_t *uni_ac_vlc_len){
133     int i;
134
135     for(i=0; i<128; i++){
136         int level= i-64;
137         int run;
138         for(run=0; run<64; run++){
139             int len, bits, code;
140             
141             int alevel= ABS(level);
142             int sign= (level>>31)&1;
143
144             if (alevel > rl->max_level[0][run])
145                 code= 111; /*rl->n*/
146             else
147                 code= rl->index_run[0][run] + alevel - 1;
148
149             if (code < 111 /* rl->n */) {
150                 /* store the vlc & sign at once */
151                 len=   mpeg1_vlc[code][1]+1;
152                 bits= (mpeg1_vlc[code][0]<<1) + sign;
153             } else {
154                 len=  mpeg1_vlc[111/*rl->n*/][1]+6;
155                 bits= mpeg1_vlc[111/*rl->n*/][0]<<6;
156
157                 bits|= run;
158                 if (alevel < 128) {
159                     bits<<=8; len+=8;
160                     bits|= level & 0xff;
161                 } else {
162                     bits<<=16; len+=16;
163                     bits|= level & 0xff;
164                     if (level < 0) {
165                         bits|= 0x8001 + level + 255;
166                     } else {
167                         bits|= level & 0xffff;
168                     }
169                 }
170             }
171
172             uni_ac_vlc_bits[UNI_AC_ENC_INDEX(run, i)]= bits;
173             uni_ac_vlc_len [UNI_AC_ENC_INDEX(run, i)]= len;
174         }
175     }
176 }
177
178 static void put_header(MpegEncContext *s, int header)
179 {
180     align_put_bits(&s->pb);
181     put_bits(&s->pb, 16, header>>16);
182     put_bits(&s->pb, 16, header&0xFFFF);
183 }
184
185 /* put sequence header if needed */
186 static void mpeg1_encode_sequence_header(MpegEncContext *s)
187 {
188         unsigned int vbv_buffer_size;
189         unsigned int fps, v;
190         int n, i;
191         uint64_t time_code;
192         float best_aspect_error= 1E10;
193         float aspect_ratio= s->avctx->aspect_ratio;
194         int constraint_parameter_flag;
195         
196         if(aspect_ratio==0.0) aspect_ratio= s->width / (float)s->height; //pixel aspect 1:1 (VGA)
197         
198         if (s->current_picture.key_frame) {
199             /* mpeg1 header repeated every gop */
200             put_header(s, SEQ_START_CODE);
201             
202             /* search closest frame rate */
203             {
204                 int i, dmin, d;
205                 s->frame_rate_index = 0;
206                 dmin = 0x7fffffff;
207                 for(i=1;i<14;i++) {
208                     if(s->avctx->strict_std_compliance >= 0 && i>=9) break;
209                      
210                     d = abs(MPEG1_FRAME_RATE_BASE*(int64_t)s->avctx->frame_rate/s->avctx->frame_rate_base - frame_rate_tab[i]);
211                     if (d < dmin) {
212                         dmin = d;
213                         s->frame_rate_index = i;
214                     }
215                 }
216             }
217  
218             put_bits(&s->pb, 12, s->width);
219             put_bits(&s->pb, 12, s->height);
220             
221             for(i=1; i<15; i++){
222                 float error= mpeg1_aspect[i] - s->width/(s->height*aspect_ratio);
223                 error= ABS(error);
224                 
225                 if(error < best_aspect_error){
226                     best_aspect_error= error;
227                     s->aspect_ratio_info= i;
228                 }
229             }
230             
231             put_bits(&s->pb, 4, s->aspect_ratio_info);
232             put_bits(&s->pb, 4, s->frame_rate_index);
233             
234             if(s->avctx->rc_max_rate){
235                 v = (s->avctx->rc_max_rate + 399) / 400;
236                 if (v > 0x3ffff && s->codec_id == CODEC_ID_MPEG1VIDEO)
237                     v = 0x3ffff;
238             }else{
239                 v= 0x3FFFF;
240             }
241
242             if(s->avctx->rc_buffer_size)
243                 vbv_buffer_size = s->avctx->rc_buffer_size;
244             else
245                 /* VBV calculation: Scaled so that a VCD has the proper VBV size of 40 kilobytes */
246                 vbv_buffer_size = (( 20 * s->bit_rate) / (1151929 / 2)) * 8 * 1024;
247             vbv_buffer_size= (vbv_buffer_size + 16383) / 16384;
248
249             put_bits(&s->pb, 18, v & 0x3FFFF);
250             put_bits(&s->pb, 1, 1); /* marker */
251             put_bits(&s->pb, 10, vbv_buffer_size & 0x3FF);
252
253             constraint_parameter_flag= 
254                 s->width <= 768 && s->height <= 576 && 
255                 s->mb_width * s->mb_height <= 396 &&
256                 s->mb_width * s->mb_height * frame_rate_tab[s->frame_rate_index] <= MPEG1_FRAME_RATE_BASE*396*25 &&
257                 frame_rate_tab[s->frame_rate_index] <= MPEG1_FRAME_RATE_BASE*30 &&
258                 vbv_buffer_size <= 20 &&
259                 v <= 1856000/400 &&
260                 s->codec_id == CODEC_ID_MPEG1VIDEO;
261                 
262             put_bits(&s->pb, 1, constraint_parameter_flag);
263             
264             ff_write_quant_matrix(&s->pb, s->avctx->intra_matrix);
265             ff_write_quant_matrix(&s->pb, s->avctx->inter_matrix);
266
267             if(s->codec_id == CODEC_ID_MPEG2VIDEO){
268                 put_header(s, EXT_START_CODE);
269                 put_bits(&s->pb, 4, 1); //seq ext
270                 put_bits(&s->pb, 1, 0); //esc
271                 put_bits(&s->pb, 3, 4); //profile
272                 put_bits(&s->pb, 4, 8); //level
273                 put_bits(&s->pb, 1, s->progressive_sequence=1);
274                 put_bits(&s->pb, 2, 1); //chroma format 4:2:0
275                 put_bits(&s->pb, 2, 0); //horizontal size ext
276                 put_bits(&s->pb, 2, 0); //vertical size ext
277                 put_bits(&s->pb, 12, v>>18); //bitrate ext
278                 put_bits(&s->pb, 1, 1); //marker
279                 put_bits(&s->pb, 8, vbv_buffer_size >>10); //vbv buffer ext
280                 put_bits(&s->pb, 1, s->low_delay);
281                 put_bits(&s->pb, 2, 0); // frame_rate_ext_n
282                 put_bits(&s->pb, 5, 0); // frame_rate_ext_d
283             }
284             
285             put_header(s, GOP_START_CODE);
286             put_bits(&s->pb, 1, 0); /* do drop frame */
287             /* time code : we must convert from the real frame rate to a
288                fake mpeg frame rate in case of low frame rate */
289             fps = frame_rate_tab[s->frame_rate_index];
290             time_code = (int64_t)s->fake_picture_number * MPEG1_FRAME_RATE_BASE;
291             s->gop_picture_number = s->fake_picture_number;
292             put_bits(&s->pb, 5, (uint32_t)((time_code / (fps * 3600)) % 24));
293             put_bits(&s->pb, 6, (uint32_t)((time_code / (fps * 60)) % 60));
294             put_bits(&s->pb, 1, 1);
295             put_bits(&s->pb, 6, (uint32_t)((time_code / fps) % 60));
296             put_bits(&s->pb, 6, (uint32_t)((time_code % fps) / MPEG1_FRAME_RATE_BASE));
297             put_bits(&s->pb, 1, 0); /* closed gop */
298             put_bits(&s->pb, 1, 0); /* broken link */
299         }
300
301         if (s->avctx->frame_rate < (24 * s->avctx->frame_rate_base) && s->picture_number > 0) {
302             /* insert empty P pictures to slow down to the desired
303                frame rate. Each fake pictures takes about 20 bytes */
304             fps = frame_rate_tab[s->frame_rate_index];
305             n = av_rescale((int64_t)s->picture_number * s->avctx->frame_rate_base, fps, s->avctx->frame_rate) / MPEG1_FRAME_RATE_BASE - 1;
306             while (s->fake_picture_number < n) {
307                 mpeg1_skip_picture(s, s->fake_picture_number - 
308                                    s->gop_picture_number); 
309                 s->fake_picture_number++;
310             }
311
312         }
313 }
314
315 static inline void encode_mb_skip_run(MpegEncContext *s, int run){
316     while (run >= 33) {
317         put_bits(&s->pb, 11, 0x008);
318         run -= 33;
319     }
320     put_bits(&s->pb, mbAddrIncrTable[run][1], 
321              mbAddrIncrTable[run][0]);
322 }
323
324 /* insert a fake P picture */
325 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
326 {
327     assert(s->codec_id == CODEC_ID_MPEG1VIDEO); // mpeg2 can do these repeat things
328
329     /* mpeg1 picture header */
330     put_header(s, PICTURE_START_CODE);
331     /* temporal reference */
332     put_bits(&s->pb, 10, pict_num & 0x3ff); 
333     
334     put_bits(&s->pb, 3, P_TYPE);
335     put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
336     
337     put_bits(&s->pb, 1, 1); /* integer coordinates */
338     put_bits(&s->pb, 3, 1); /* forward_f_code */
339     
340     put_bits(&s->pb, 1, 0); /* extra bit picture */
341     
342     /* only one slice */
343     put_header(s, SLICE_MIN_START_CODE);
344     put_bits(&s->pb, 5, 1); /* quantizer scale */
345     put_bits(&s->pb, 1, 0); /* slice extra information */
346     
347     encode_mb_skip_run(s, 0);
348     
349     /* empty macroblock */
350     put_bits(&s->pb, 3, 1); /* motion only */
351     
352     /* zero motion x & y */
353     put_bits(&s->pb, 1, 1); 
354     put_bits(&s->pb, 1, 1); 
355
356     /* output a number of empty slice */
357     encode_mb_skip_run(s, s->mb_width * s->mb_height - 2);
358     
359     /* empty macroblock */
360     put_bits(&s->pb, 3, 1); /* motion only */
361     
362     /* zero motion x & y */
363     put_bits(&s->pb, 1, 1); 
364     put_bits(&s->pb, 1, 1); 
365 }
366 #endif //CONFIG_ENCODERS
367
368 static void common_init(MpegEncContext *s)
369 {
370     s->y_dc_scale_table=
371     s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
372 }
373
374 void ff_mpeg1_clean_buffers(MpegEncContext *s){
375     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
376     s->last_dc[1] = s->last_dc[0];
377     s->last_dc[2] = s->last_dc[0];
378     memset(s->last_mv, 0, sizeof(s->last_mv));
379 }
380
381 #ifdef CONFIG_ENCODERS
382
383 void ff_mpeg1_encode_slice_header(MpegEncContext *s){
384     put_header(s, SLICE_MIN_START_CODE + s->mb_y);
385     put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
386     put_bits(&s->pb, 1, 0); /* slice extra information */
387 }
388
389 void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
390 {
391     mpeg1_encode_sequence_header(s);
392
393     /* mpeg1 picture header */
394     put_header(s, PICTURE_START_CODE);
395     /* temporal reference */
396
397     // RAL: s->picture_number instead of s->fake_picture_number
398     put_bits(&s->pb, 10, (s->picture_number - 
399                           s->gop_picture_number) & 0x3ff); 
400     s->fake_picture_number++;
401     
402     put_bits(&s->pb, 3, s->pict_type);
403     put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
404     
405     // RAL: Forward f_code also needed for B frames
406     if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
407         put_bits(&s->pb, 1, 0); /* half pel coordinates */
408         if(s->codec_id == CODEC_ID_MPEG1VIDEO)
409             put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
410         else
411             put_bits(&s->pb, 3, 7); /* forward_f_code */
412     }
413     
414     // RAL: Backward f_code necessary for B frames
415     if (s->pict_type == B_TYPE) {
416         put_bits(&s->pb, 1, 0); /* half pel coordinates */
417         if(s->codec_id == CODEC_ID_MPEG1VIDEO)
418             put_bits(&s->pb, 3, s->b_code); /* backward_f_code */
419         else
420             put_bits(&s->pb, 3, 7); /* backward_f_code */
421     }
422
423     put_bits(&s->pb, 1, 0); /* extra bit picture */
424     
425     if(s->codec_id == CODEC_ID_MPEG2VIDEO){
426         put_header(s, EXT_START_CODE);
427         put_bits(&s->pb, 4, 8); //pic ext
428         if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
429             put_bits(&s->pb, 4, s->f_code);
430             put_bits(&s->pb, 4, s->f_code);
431         }else{
432             put_bits(&s->pb, 8, 255);
433         }
434         if (s->pict_type == B_TYPE) {
435             put_bits(&s->pb, 4, s->b_code);
436             put_bits(&s->pb, 4, s->b_code);
437         }else{
438             put_bits(&s->pb, 8, 255);
439         }
440         put_bits(&s->pb, 2, s->intra_dc_precision);
441         put_bits(&s->pb, 2, s->picture_structure= PICT_FRAME);
442         put_bits(&s->pb, 1, s->top_field_first);
443         put_bits(&s->pb, 1, s->frame_pred_frame_dct= 1);
444         put_bits(&s->pb, 1, s->concealment_motion_vectors);
445         put_bits(&s->pb, 1, s->q_scale_type);
446         put_bits(&s->pb, 1, s->intra_vlc_format);
447         put_bits(&s->pb, 1, s->alternate_scan);
448         put_bits(&s->pb, 1, s->repeat_first_field);
449         put_bits(&s->pb, 1, s->chroma_420_type=1);
450         put_bits(&s->pb, 1, s->progressive_frame=1);
451         put_bits(&s->pb, 1, 0); //composite_display_flag
452     }
453     
454     s->mb_y=0;
455     ff_mpeg1_encode_slice_header(s);
456 }
457
458 void mpeg1_encode_mb(MpegEncContext *s,
459                      DCTELEM block[6][64],
460                      int motion_x, int motion_y)
461 {
462     int i, cbp;
463     const int mb_x = s->mb_x;
464     const int mb_y = s->mb_y;
465     const int first_mb= mb_x == s->resync_mb_x && mb_y == s->resync_mb_y;
466
467     /* compute cbp */
468     cbp = 0;
469     for(i=0;i<6;i++) {
470         if (s->block_last_index[i] >= 0)
471             cbp |= 1 << (5 - i);
472     }
473
474     if (cbp == 0 && !first_mb && (mb_x != s->mb_width - 1 || (mb_y != s->mb_height - 1 && s->codec_id == CODEC_ID_MPEG1VIDEO)) && 
475         ((s->pict_type == P_TYPE && (motion_x | motion_y) == 0) ||
476         (s->pict_type == B_TYPE && s->mv_dir == s->last_mv_dir && (((s->mv_dir & MV_DIR_FORWARD) ? ((s->mv[0][0][0] - s->last_mv[0][0][0])|(s->mv[0][0][1] - s->last_mv[0][0][1])) : 0) |
477         ((s->mv_dir & MV_DIR_BACKWARD) ? ((s->mv[1][0][0] - s->last_mv[1][0][0])|(s->mv[1][0][1] - s->last_mv[1][0][1])) : 0)) == 0))) {
478         s->mb_skip_run++;
479         s->qscale -= s->dquant;
480         s->skip_count++;
481         s->misc_bits++;
482         s->last_bits++;
483     } else {
484         if(first_mb){
485             assert(s->mb_skip_run == 0);
486             encode_mb_skip_run(s, s->mb_x);
487         }else{
488             encode_mb_skip_run(s, s->mb_skip_run);
489         }
490         
491         if (s->pict_type == I_TYPE) {
492             if(s->dquant && cbp){
493                 put_bits(&s->pb, 2, 1); /* macroblock_type : macroblock_quant = 1 */
494                 put_bits(&s->pb, 5, s->qscale);
495             }else{
496                 put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
497                 s->qscale -= s->dquant;
498             }
499             s->misc_bits+= get_bits_diff(s);
500             s->i_count++;
501         } else if (s->mb_intra) {
502             if(s->dquant && cbp){
503                 put_bits(&s->pb, 6, 0x01);
504                 put_bits(&s->pb, 5, s->qscale);
505             }else{
506                 put_bits(&s->pb, 5, 0x03);
507                 s->qscale -= s->dquant;
508             }
509             s->misc_bits+= get_bits_diff(s);
510             s->i_count++;
511             s->last_mv[0][0][0] = 
512             s->last_mv[0][0][1] = 0;
513         } else if (s->pict_type == P_TYPE) { 
514                 if (cbp != 0) {
515                     if (motion_x == 0 && motion_y == 0) {
516                         if(s->dquant){
517                             put_bits(&s->pb, 5, 1); /* macroblock_pattern & quant */
518                             put_bits(&s->pb, 5, s->qscale);
519                         }else{
520                             put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
521                         }
522                         s->misc_bits+= get_bits_diff(s);
523                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
524                     } else {
525                         if(s->dquant){
526                             put_bits(&s->pb, 5, 2); /* motion + cbp */
527                             put_bits(&s->pb, 5, s->qscale);
528                         }else{
529                             put_bits(&s->pb, 1, 1); /* motion + cbp */
530                         }
531                         s->misc_bits+= get_bits_diff(s);
532                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);    // RAL: f_code parameter added
533                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);    // RAL: f_code parameter added
534                         s->mv_bits+= get_bits_diff(s);
535                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
536                     }
537                 } else {
538                     put_bits(&s->pb, 3, 1); /* motion only */
539                     mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);    // RAL: f_code parameter added
540                     mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);    // RAL: f_code parameter added
541                     s->qscale -= s->dquant;
542                     s->mv_bits+= get_bits_diff(s);
543                 }
544                 s->f_count++;
545         } else
546             {    // RAL: All the following bloc added for B frames:
547                 if (cbp != 0)
548                     {    // With coded bloc pattern
549                     if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
550                         {    // Bi-directional motion
551                         if (s->dquant)
552                             {    // With QScale
553                             put_bits(&s->pb, 5, 2);
554                             put_bits(&s->pb, 5, s->qscale);
555                             }
556                         else    // Without QScale
557                             put_bits(&s->pb, 2, 3);
558                         s->misc_bits += get_bits_diff(s);
559                         mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
560                         mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
561                         mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
562                         mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
563                         s->b_count++;
564                         s->f_count++;
565                         s->mv_bits += get_bits_diff(s);
566                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
567                         }
568                     else if (s->mv_dir == MV_DIR_BACKWARD)
569                         {    // Backward motion
570                         if (s->dquant)
571                             {    // With QScale
572                             put_bits(&s->pb, 6, 2);
573                             put_bits(&s->pb, 5, s->qscale);
574                             }
575                         else    // Without QScale
576                             put_bits(&s->pb, 3, 3);
577                         s->misc_bits += get_bits_diff(s);
578                         mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code); 
579                         mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code); 
580                         s->b_count++;
581                         s->mv_bits += get_bits_diff(s);
582                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
583                         }
584                     else if (s->mv_dir == MV_DIR_FORWARD)
585                         {    // Forward motion
586                         if (s->dquant)
587                             {    // With QScale
588                             put_bits(&s->pb, 6, 3);
589                             put_bits(&s->pb, 5, s->qscale);
590                             }
591                         else    // Without QScale
592                             put_bits(&s->pb, 4, 3);
593                         s->misc_bits += get_bits_diff(s);
594                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code); 
595                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code); 
596                         s->f_count++;
597                         s->mv_bits += get_bits_diff(s);
598                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
599                         }
600                     }
601                 else
602                     {    // No coded bloc pattern
603                     if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
604                         {    // Bi-directional motion 
605                         put_bits(&s->pb, 2, 2); /* backward & forward motion */
606                         mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
607                         mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
608                         mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
609                         mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
610                         s->b_count++;
611                         s->f_count++;
612                         }
613                     else if (s->mv_dir == MV_DIR_BACKWARD)
614                         {    // Backward motion
615                         put_bits(&s->pb, 3, 2); /* backward motion only */
616                         mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code); 
617                         mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code); 
618                         s->b_count++;
619                         }
620                     else if (s->mv_dir == MV_DIR_FORWARD)
621                         {    // Forward motion
622                         put_bits(&s->pb, 4, 2); /* forward motion only */
623                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code); 
624                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code); 
625                         s->f_count++;
626                         }
627                     s->qscale -= s->dquant;
628                     s->mv_bits += get_bits_diff(s);
629                     }
630             // End of bloc from RAL
631             }
632         for(i=0;i<6;i++) {
633             if (cbp & (1 << (5 - i))) {
634                 mpeg1_encode_block(s, block[i], i);
635             }
636         }
637         s->mb_skip_run = 0;
638         if(s->mb_intra)
639             s->i_tex_bits+= get_bits_diff(s);
640         else
641             s->p_tex_bits+= get_bits_diff(s);
642     }
643
644     // RAL: By this:
645     if (s->mv_dir & MV_DIR_FORWARD)
646         {
647         s->last_mv[0][0][0]= s->mv[0][0][0];
648         s->last_mv[0][0][1]= s->mv[0][0][1];
649         }
650     if (s->mv_dir & MV_DIR_BACKWARD)
651         {
652         s->last_mv[1][0][0]= s->mv[1][0][0];
653         s->last_mv[1][0][1]= s->mv[1][0][1];
654         }
655 }
656
657 // RAL: Parameter added: f_or_b_code
658 static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code)
659 {
660     int code, bit_size, l, m, bits, range, sign;
661
662     if (val == 0) {
663         /* zero vector */
664         code = 0;
665         put_bits(&s->pb,
666                  mbMotionVectorTable[0][1], 
667                  mbMotionVectorTable[0][0]); 
668     } else {
669         bit_size = f_or_b_code - 1;
670         range = 1 << bit_size;
671         /* modulo encoding */
672         l = 16 * range;
673         m = 2 * l;
674         if (val < -l) {
675             val += m;
676         } else if (val >= l) {
677             val -= m;
678         }
679
680         if (val >= 0) {
681             val--;
682             code = (val >> bit_size) + 1;
683             bits = val & (range - 1);
684             sign = 0;
685         } else {
686             val = -val;
687             val--;
688             code = (val >> bit_size) + 1;
689             bits = val & (range - 1);
690             sign = 1;
691         }
692
693         assert(code > 0 && code <= 16);
694
695         put_bits(&s->pb,
696                  mbMotionVectorTable[code][1], 
697                  mbMotionVectorTable[code][0]); 
698
699         put_bits(&s->pb, 1, sign);
700         if (bit_size > 0) {
701             put_bits(&s->pb, bit_size, bits);
702         }
703     }
704 }
705
706 void ff_mpeg1_encode_init(MpegEncContext *s)
707 {
708     static int done=0;
709
710     common_init(s);
711
712     if(!done){
713         int f_code;
714         int mv;
715         int i;
716
717         done=1;
718         init_rl(&rl_mpeg1);
719
720         for(i=0; i<64; i++)
721         {
722                 mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
723                 mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
724         }
725         
726         init_uni_ac_vlc(&rl_mpeg1, uni_mpeg1_ac_vlc_bits, uni_mpeg1_ac_vlc_len);
727
728         /* build unified dc encoding tables */
729         for(i=-255; i<256; i++)
730         {
731                 int adiff, index;
732                 int bits, code;
733                 int diff=i;
734
735                 adiff = ABS(diff);
736                 if(diff<0) diff--;
737                 index = vlc_dc_table[adiff];
738
739                 bits= vlc_dc_lum_bits[index] + index;
740                 code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
741                 mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
742                 
743                 bits= vlc_dc_chroma_bits[index] + index;
744                 code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
745                 mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
746         }
747
748         mv_penalty= av_mallocz( sizeof(uint8_t)*(MAX_FCODE+1)*(2*MAX_MV+1) );
749
750         for(f_code=1; f_code<=MAX_FCODE; f_code++){
751             for(mv=-MAX_MV; mv<=MAX_MV; mv++){
752                 int len;
753
754                 if(mv==0) len= mbMotionVectorTable[0][1];
755                 else{
756                     int val, bit_size, range, code;
757
758                     bit_size = s->f_code - 1;
759                     range = 1 << bit_size;
760
761                     val=mv;
762                     if (val < 0) 
763                         val = -val;
764                     val--;
765                     code = (val >> bit_size) + 1;
766                     if(code<17){
767                         len= mbMotionVectorTable[code][1] + 1 + bit_size;
768                     }else{
769                         len= mbMotionVectorTable[16][1] + 2 + bit_size;
770                     }
771                 }
772
773                 mv_penalty[f_code][mv+MAX_MV]= len;
774             }
775         }
776         
777
778         for(f_code=MAX_FCODE; f_code>0; f_code--){
779             for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
780                 fcode_tab[mv+MAX_MV]= f_code;
781             }
782         }
783     }
784     s->me.mv_penalty= mv_penalty;
785     s->fcode_tab= fcode_tab;
786     if(s->codec_id == CODEC_ID_MPEG1VIDEO){
787         s->min_qcoeff=-255;
788         s->max_qcoeff= 255;
789     }else{
790         s->min_qcoeff=-2047;
791         s->max_qcoeff= 2047;
792     }
793     s->intra_ac_vlc_length=
794     s->inter_ac_vlc_length=
795     s->intra_ac_vlc_last_length=
796     s->inter_ac_vlc_last_length= uni_mpeg1_ac_vlc_len;
797 }
798
799 static inline void encode_dc(MpegEncContext *s, int diff, int component)
800 {
801     if (component == 0) {
802         put_bits(
803             &s->pb, 
804             mpeg1_lum_dc_uni[diff+255]&0xFF,
805             mpeg1_lum_dc_uni[diff+255]>>8);
806     } else {
807         put_bits(
808             &s->pb, 
809             mpeg1_chr_dc_uni[diff+255]&0xFF,
810             mpeg1_chr_dc_uni[diff+255]>>8);
811     }
812 }
813
814 static void mpeg1_encode_block(MpegEncContext *s, 
815                                DCTELEM *block, 
816                                int n)
817 {
818     int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
819     int code, component;
820 //    RLTable *rl = &rl_mpeg1;
821
822     last_index = s->block_last_index[n];
823
824     /* DC coef */
825     if (s->mb_intra) {
826         component = (n <= 3 ? 0 : n - 4 + 1);
827         dc = block[0]; /* overflow is impossible */
828         diff = dc - s->last_dc[component];
829         encode_dc(s, diff, component);
830         s->last_dc[component] = dc;
831         i = 1;
832 /*
833         if (s->intra_vlc_format)
834             rl = &rl_mpeg2;
835         else
836             rl = &rl_mpeg1;
837 */
838     } else {
839         /* encode the first coefficient : needs to be done here because
840            it is handled slightly differently */
841         level = block[0];
842         if (abs(level) == 1) {
843                 code = ((uint32_t)level >> 31); /* the sign bit */
844                 put_bits(&s->pb, 2, code | 0x02);
845                 i = 1;
846         } else {
847             i = 0;
848             last_non_zero = -1;
849             goto next_coef;
850         }
851     }
852
853     /* now quantify & encode AC coefs */
854     last_non_zero = i - 1;
855
856     for(;i<=last_index;i++) {
857         j = s->intra_scantable.permutated[i];
858         level = block[j];
859     next_coef:
860 #if 0
861         if (level != 0)
862             dprintf("level[%d]=%d\n", i, level);
863 #endif            
864         /* encode using VLC */
865         if (level != 0) {
866             run = i - last_non_zero - 1;
867             
868             alevel= level;
869             MASK_ABS(sign, alevel)
870             sign&=1;
871
872 //            code = get_rl_index(rl, 0, run, alevel);
873             if (alevel <= mpeg1_max_level[0][run]){
874                 code= mpeg1_index_run[0][run] + alevel - 1;
875                 /* store the vlc & sign at once */
876                 put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
877             } else {
878                 /* escape seems to be pretty rare <5% so i dont optimize it */
879                 put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
880                 /* escape: only clip in this case */
881                 put_bits(&s->pb, 6, run);
882                 if(s->codec_id == CODEC_ID_MPEG1VIDEO){
883                     if (alevel < 128) {
884                         put_bits(&s->pb, 8, level & 0xff);
885                     } else {
886                         if (level < 0) {
887                             put_bits(&s->pb, 16, 0x8001 + level + 255);
888                         } else {
889                             put_bits(&s->pb, 16, level & 0xffff);
890                         }
891                     }
892                 }else{
893                     put_bits(&s->pb, 12, level & 0xfff);
894                 }
895             }
896             last_non_zero = i;
897         }
898     }
899     /* end of block */
900     put_bits(&s->pb, 2, 0x2);
901 }
902 #endif //CONFIG_ENCODERS
903
904 /******************************************/
905 /* decoding */
906
907 static VLC dc_lum_vlc;
908 static VLC dc_chroma_vlc;
909 static VLC mv_vlc;
910 static VLC mbincr_vlc;
911 static VLC mb_ptype_vlc;
912 static VLC mb_btype_vlc;
913 static VLC mb_pat_vlc;
914
915 static void init_vlcs()
916 {
917     static int done = 0;
918
919     if (!done) {
920         done = 1;
921
922         init_vlc(&dc_lum_vlc, DC_VLC_BITS, 12, 
923                  vlc_dc_lum_bits, 1, 1,
924                  vlc_dc_lum_code, 2, 2);
925         init_vlc(&dc_chroma_vlc,  DC_VLC_BITS, 12, 
926                  vlc_dc_chroma_bits, 1, 1,
927                  vlc_dc_chroma_code, 2, 2);
928         init_vlc(&mv_vlc, MV_VLC_BITS, 17, 
929                  &mbMotionVectorTable[0][1], 2, 1,
930                  &mbMotionVectorTable[0][0], 2, 1);
931         init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 36, 
932                  &mbAddrIncrTable[0][1], 2, 1,
933                  &mbAddrIncrTable[0][0], 2, 1);
934         init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 63, 
935                  &mbPatTable[0][1], 2, 1,
936                  &mbPatTable[0][0], 2, 1);
937         
938         init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7, 
939                  &table_mb_ptype[0][1], 2, 1,
940                  &table_mb_ptype[0][0], 2, 1);
941         init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11, 
942                  &table_mb_btype[0][1], 2, 1,
943                  &table_mb_btype[0][0], 2, 1);
944         init_rl(&rl_mpeg1);
945         init_rl(&rl_mpeg2);
946
947         init_2d_vlc_rl(&rl_mpeg1);
948         init_2d_vlc_rl(&rl_mpeg2);
949     }
950 }
951
952 static inline int get_dmv(MpegEncContext *s)
953 {
954     if(get_bits1(&s->gb)) 
955         return 1 - (get_bits1(&s->gb) << 1);
956     else
957         return 0;
958 }
959
960 static inline int get_qscale(MpegEncContext *s)
961 {
962     int qscale = get_bits(&s->gb, 5);
963     if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
964         if (s->q_scale_type) {
965             return non_linear_qscale[qscale];
966         } else {
967             return qscale << 1;
968         }
969     }
970     return qscale;
971 }
972
973 /* motion type (for mpeg2) */
974 #define MT_FIELD 1
975 #define MT_FRAME 2
976 #define MT_16X8  2
977 #define MT_DMV   3
978
979 static int mpeg_decode_mb(MpegEncContext *s,
980                           DCTELEM block[6][64])
981 {
982     int i, j, k, cbp, val, mb_type, motion_type;
983     
984     dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
985
986     assert(s->mb_skiped==0);
987
988     if (s->mb_skip_run-- != 0) {
989         if(s->pict_type == I_TYPE){
990             fprintf(stderr, "skiped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
991             return -1;
992         }
993     
994         /* skip mb */
995         s->mb_intra = 0;
996         for(i=0;i<6;i++)
997             s->block_last_index[i] = -1;
998         s->mv_type = MV_TYPE_16X16;
999         if (s->pict_type == P_TYPE) {
1000             /* if P type, zero motion vector is implied */
1001             s->mv_dir = MV_DIR_FORWARD;
1002             s->mv[0][0][0] = s->mv[0][0][1] = 0;
1003             s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1004             s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1005             s->mb_skiped = 1;
1006             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
1007         } else {
1008             /* if B type, reuse previous vectors and directions */
1009             s->mv[0][0][0] = s->last_mv[0][0][0];
1010             s->mv[0][0][1] = s->last_mv[0][0][1];
1011             s->mv[1][0][0] = s->last_mv[1][0][0];
1012             s->mv[1][0][1] = s->last_mv[1][0][1];
1013
1014             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= 
1015                 s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1] | MB_TYPE_SKIP;
1016 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
1017
1018             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0) 
1019                 s->mb_skiped = 1;
1020         }
1021
1022         return 0;
1023     }
1024
1025     switch(s->pict_type) {
1026     default:
1027     case I_TYPE:
1028         if (get_bits1(&s->gb) == 0) {
1029             if (get_bits1(&s->gb) == 0){
1030                 fprintf(stderr, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
1031                 return -1;
1032             }
1033             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
1034         } else {
1035             mb_type = MB_TYPE_INTRA;
1036         }
1037         break;
1038     case P_TYPE:
1039         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
1040         if (mb_type < 0){
1041             fprintf(stderr, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
1042             return -1;
1043         }
1044         mb_type = ptype2mb_type[ mb_type ];
1045         break;
1046     case B_TYPE:
1047         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
1048         if (mb_type < 0){
1049             fprintf(stderr, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
1050             return -1;
1051         }
1052         mb_type = btype2mb_type[ mb_type ];
1053         break;
1054     }
1055     dprintf("mb_type=%x\n", mb_type);
1056 //    motion_type = 0; /* avoid warning */
1057     if (IS_INTRA(mb_type)) {
1058         /* compute dct type */
1059         if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
1060             !s->frame_pred_frame_dct) {
1061             s->interlaced_dct = get_bits1(&s->gb);
1062         }
1063
1064         if (IS_QUANT(mb_type))
1065             s->qscale = get_qscale(s);
1066         
1067         if (s->concealment_motion_vectors) {
1068             /* just parse them */
1069             if (s->picture_structure != PICT_FRAME) 
1070                 skip_bits1(&s->gb); /* field select */
1071             
1072             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] = 
1073                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
1074             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] = 
1075                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
1076
1077             skip_bits1(&s->gb); /* marker */
1078         }else
1079             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
1080         s->mb_intra = 1;
1081
1082         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
1083             for(i=0;i<6;i++) {
1084                 if (mpeg2_decode_block_intra(s, block[i], i) < 0)
1085                     return -1;
1086             }
1087         } else {
1088             for(i=0;i<6;i++) {
1089                 if (mpeg1_decode_block_intra(s, block[i], i) < 0)
1090                     return -1;
1091             }
1092         }
1093     } else {
1094         if (mb_type & MB_TYPE_ZERO_MV){
1095             assert(mb_type & MB_TYPE_PAT);
1096
1097             /* compute dct type */
1098             if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
1099                 !s->frame_pred_frame_dct) {
1100                 s->interlaced_dct = get_bits1(&s->gb);
1101             }
1102
1103             if (IS_QUANT(mb_type))
1104                 s->qscale = get_qscale(s);
1105
1106             s->mv_dir = MV_DIR_FORWARD;
1107             s->mv_type = MV_TYPE_16X16;
1108             s->last_mv[0][0][0] = 0;
1109             s->last_mv[0][0][1] = 0;
1110             s->last_mv[0][1][0] = 0;
1111             s->last_mv[0][1][1] = 0;
1112             s->mv[0][0][0] = 0;
1113             s->mv[0][0][1] = 0;
1114         }else{
1115             assert(mb_type & MB_TYPE_L0L1);
1116 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
1117             /* get additionnal motion vector type */
1118             if (s->frame_pred_frame_dct) 
1119                 motion_type = MT_FRAME;
1120             else{
1121                 motion_type = get_bits(&s->gb, 2);
1122             }
1123
1124             /* compute dct type */
1125             if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
1126                 !s->frame_pred_frame_dct && IS_PAT(mb_type)) {
1127                 s->interlaced_dct = get_bits1(&s->gb);
1128             }
1129
1130             if (IS_QUANT(mb_type))
1131                 s->qscale = get_qscale(s);
1132
1133             /* motion vectors */
1134             s->mv_dir = 0;
1135             for(i=0;i<2;i++) {
1136                 if (USES_LIST(mb_type, i)) {
1137                     s->mv_dir |= (MV_DIR_FORWARD >> i);
1138                     dprintf("motion_type=%d\n", motion_type);
1139                     switch(motion_type) {
1140                     case MT_FRAME: /* or MT_16X8 */
1141                         if (s->picture_structure == PICT_FRAME) {
1142                             /* MT_FRAME */
1143                             mb_type |= MB_TYPE_16x16; 
1144                             s->mv_type = MV_TYPE_16X16;
1145                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] = 
1146                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
1147                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] = 
1148                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
1149                             /* full_pel: only for mpeg1 */
1150                             if (s->full_pel[i]){
1151                                 s->mv[i][0][0] <<= 1;
1152                                 s->mv[i][0][1] <<= 1;
1153                             }
1154                         } else {
1155                             /* MT_16X8 */
1156                             mb_type |= MB_TYPE_16x8; 
1157                             s->mv_type = MV_TYPE_16X8;
1158                             for(j=0;j<2;j++) {
1159                                 s->field_select[i][j] = get_bits1(&s->gb);
1160                                 for(k=0;k<2;k++) {
1161                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
1162                                                              s->last_mv[i][j][k]);
1163                                     s->last_mv[i][j][k] = val;
1164                                     s->mv[i][j][k] = val;
1165                                 }
1166                             }
1167                         }
1168                         break;
1169                     case MT_FIELD:
1170                         s->mv_type = MV_TYPE_FIELD;
1171                         if (s->picture_structure == PICT_FRAME) {
1172                             mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED; 
1173                             for(j=0;j<2;j++) {
1174                                 s->field_select[i][j] = get_bits1(&s->gb);
1175                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
1176                                                          s->last_mv[i][j][0]);
1177                                 s->last_mv[i][j][0] = val;
1178                                 s->mv[i][j][0] = val;
1179                                 dprintf("fmx=%d\n", val);
1180                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
1181                                                          s->last_mv[i][j][1] >> 1);
1182                                 s->last_mv[i][j][1] = val << 1;
1183                                 s->mv[i][j][1] = val;
1184                                 dprintf("fmy=%d\n", val);
1185                             }
1186                         } else {
1187                             mb_type |= MB_TYPE_16x16; 
1188                             s->field_select[i][0] = get_bits1(&s->gb);
1189                             for(k=0;k<2;k++) {
1190                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
1191                                                          s->last_mv[i][0][k]);
1192                                 s->last_mv[i][0][k] = val;
1193                                 s->last_mv[i][1][k] = val;
1194                                 s->mv[i][0][k] = val;
1195                             }
1196                         }
1197                         break;
1198                     case MT_DMV:
1199                         {
1200                             int dmx, dmy, mx, my, m;
1201
1202                             mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0], 
1203                                                     s->last_mv[i][0][0]);
1204                             s->last_mv[i][0][0] = mx;
1205                             s->last_mv[i][1][0] = mx;
1206                             dmx = get_dmv(s);
1207                             my = mpeg_decode_motion(s, s->mpeg_f_code[i][1], 
1208                                                     s->last_mv[i][0][1] >> 1);
1209                             dmy = get_dmv(s);
1210                             s->mv_type = MV_TYPE_DMV;
1211
1212
1213                             s->last_mv[i][0][1] = my<<1;
1214                             s->last_mv[i][1][1] = my<<1;
1215
1216                             s->mv[i][0][0] = mx;
1217                             s->mv[i][0][1] = my;
1218                             s->mv[i][1][0] = mx;//not used
1219                             s->mv[i][1][1] = my;//not used
1220
1221                             if (s->picture_structure == PICT_FRAME) {
1222                                 mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED; 
1223
1224                                 //m = 1 + 2 * s->top_field_first;
1225                                 m = s->top_field_first ? 1 : 3;
1226
1227                                 /* top -> top pred */
1228                                 s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1229                                 s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
1230                                 m = 4 - m;
1231                                 s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1232                                 s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
1233                             } else {
1234                                 mb_type |= MB_TYPE_16x16;
1235
1236                                 s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
1237                                 s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
1238                                 if(s->picture_structure == PICT_TOP_FIELD)
1239                                     s->mv[i][2][1]--;
1240                                 else 
1241                                     s->mv[i][2][1]++;
1242                             }
1243                         }
1244                         break;
1245                     }
1246                 }
1247             }
1248         }
1249         
1250         s->mb_intra = 0;
1251
1252         if (IS_PAT(mb_type)) {
1253             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
1254             if (cbp < 0){
1255                 fprintf(stderr, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
1256                 return -1;
1257             }
1258             cbp++;
1259
1260             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
1261                 for(i=0;i<6;i++) {
1262                     if (cbp & 32) {
1263                         if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
1264                             return -1;
1265                     } else {
1266                         s->block_last_index[i] = -1;
1267                     }
1268                     cbp+=cbp;
1269                 }
1270             } else {
1271                 for(i=0;i<6;i++) {
1272                     if (cbp & 32) {
1273                         if (mpeg1_decode_block_inter(s, block[i], i) < 0)
1274                             return -1;
1275                     } else {
1276                         s->block_last_index[i] = -1;
1277                     }
1278                     cbp+=cbp;
1279                 }
1280             }
1281         }else{
1282             for(i=0;i<6;i++)
1283                 s->block_last_index[i] = -1;
1284         }
1285     }
1286
1287     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
1288
1289     return 0;
1290 }
1291
1292 /* as h263, but only 17 codes */
1293 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
1294 {
1295     int code, sign, val, l, shift;
1296
1297     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
1298     if (code == 0) {
1299         return pred;
1300     }
1301     if (code < 0) {
1302         return 0xffff;
1303     }
1304
1305     sign = get_bits1(&s->gb);
1306     shift = fcode - 1;
1307     val = code;
1308     if (shift) {
1309         val = (val - 1) << shift;
1310         val |= get_bits(&s->gb, shift);
1311         val++;
1312     }
1313     if (sign)
1314         val = -val;
1315     val += pred;
1316     
1317     /* modulo decoding */
1318     l = 1 << (shift+4);
1319     val = ((val + l)&(l*2-1)) - l;
1320     return val;
1321 }
1322
1323 static inline int decode_dc(GetBitContext *gb, int component)
1324 {
1325     int code, diff;
1326
1327     if (component == 0) {
1328         code = get_vlc2(gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
1329     } else {
1330         code = get_vlc2(gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
1331     }
1332     if (code < 0){
1333         fprintf(stderr, "invalid dc code at\n");
1334         return 0xffff;
1335     }
1336     if (code == 0) {
1337         diff = 0;
1338     } else {
1339         diff = get_xbits(gb, code);
1340     }
1341     return diff;
1342 }
1343
1344 static inline int mpeg1_decode_block_intra(MpegEncContext *s, 
1345                                DCTELEM *block, 
1346                                int n)
1347 {
1348     int level, dc, diff, i, j, run;
1349     int component;
1350     RLTable *rl = &rl_mpeg1;
1351     uint8_t * const scantable= s->intra_scantable.permutated;
1352     const uint16_t *quant_matrix= s->intra_matrix;
1353     const int qscale= s->qscale;
1354
1355     /* DC coef */
1356     component = (n <= 3 ? 0 : n - 4 + 1);
1357     diff = decode_dc(&s->gb, component);
1358     if (diff >= 0xffff)
1359         return -1;
1360     dc = s->last_dc[component];
1361     dc += diff;
1362     s->last_dc[component] = dc;
1363     block[0] = dc<<3;
1364     dprintf("dc=%d diff=%d\n", dc, diff);
1365     i = 0;
1366     {
1367         OPEN_READER(re, &s->gb);    
1368         /* now quantify & encode AC coefs */
1369         for(;;) {
1370             UPDATE_CACHE(re, &s->gb);
1371             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1372             
1373             if(level == 127){
1374                 break;
1375             } else if(level != 0) {
1376                 i += run;
1377                 j = scantable[i];
1378                 level= (level*qscale*quant_matrix[j])>>3;
1379                 level= (level-1)|1;
1380                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1381                 LAST_SKIP_BITS(re, &s->gb, 1);
1382             } else {
1383                 /* escape */
1384                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1385                 UPDATE_CACHE(re, &s->gb);
1386                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
1387                 if (level == -128) {
1388                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
1389                 } else if (level == 0) {
1390                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
1391                 }
1392                 i += run;
1393                 j = scantable[i];
1394                 if(level<0){
1395                     level= -level;
1396                     level= (level*qscale*quant_matrix[j])>>3;
1397                     level= (level-1)|1;
1398                     level= -level;
1399                 }else{
1400                     level= (level*qscale*quant_matrix[j])>>3;
1401                     level= (level-1)|1;
1402                 }
1403             }
1404             if (i > 63){
1405                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1406                 return -1;
1407             }
1408
1409             block[j] = level;
1410         }
1411         CLOSE_READER(re, &s->gb);
1412     }
1413     s->block_last_index[n] = i;
1414    return 0;
1415 }
1416
1417 static inline int mpeg1_decode_block_inter(MpegEncContext *s, 
1418                                DCTELEM *block, 
1419                                int n)
1420 {
1421     int level, i, j, run;
1422     RLTable *rl = &rl_mpeg1;
1423     uint8_t * const scantable= s->intra_scantable.permutated;
1424     const uint16_t *quant_matrix= s->inter_matrix;
1425     const int qscale= s->qscale;
1426
1427     {
1428         int v;
1429         OPEN_READER(re, &s->gb);
1430         i = -1;
1431         /* special case for the first coef. no need to add a second vlc table */
1432         UPDATE_CACHE(re, &s->gb);
1433         v= SHOW_UBITS(re, &s->gb, 2);
1434         if (v & 2) {
1435             LAST_SKIP_BITS(re, &s->gb, 2);
1436             level= (3*qscale*quant_matrix[0])>>4;
1437             level= (level-1)|1;
1438             if(v&1)
1439                 level= -level;
1440             block[0] = level;
1441             i++;
1442         }
1443
1444         /* now quantify & encode AC coefs */
1445         for(;;) {
1446             UPDATE_CACHE(re, &s->gb);
1447             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1448             
1449             if(level == 127){
1450                 break;
1451             } else if(level != 0) {
1452                 i += run;
1453                 j = scantable[i];
1454                 level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1455                 level= (level-1)|1;
1456                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1457                 LAST_SKIP_BITS(re, &s->gb, 1);
1458             } else {
1459                 /* escape */
1460                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1461                 UPDATE_CACHE(re, &s->gb);
1462                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
1463                 if (level == -128) {
1464                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
1465                 } else if (level == 0) {
1466                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
1467                 }
1468                 i += run;
1469                 j = scantable[i];
1470                 if(level<0){
1471                     level= -level;
1472                     level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1473                     level= (level-1)|1;
1474                     level= -level;
1475                 }else{
1476                     level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1477                     level= (level-1)|1;
1478                 }
1479             }
1480             if (i > 63){
1481                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1482                 return -1;
1483             }
1484
1485             block[j] = level;
1486         }
1487         CLOSE_READER(re, &s->gb);
1488     }
1489     s->block_last_index[n] = i;
1490     return 0;
1491 }
1492
1493 /* Also does unquantization here, since I will never support mpeg2
1494    encoding */
1495 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s, 
1496                                DCTELEM *block, 
1497                                int n)
1498 {
1499     int level, i, j, run;
1500     RLTable *rl = &rl_mpeg1;
1501     uint8_t * const scantable= s->intra_scantable.permutated;
1502     const uint16_t *quant_matrix;
1503     const int qscale= s->qscale;
1504     int mismatch;
1505
1506     mismatch = 1;
1507
1508     {
1509         int v;
1510         OPEN_READER(re, &s->gb);
1511         i = -1;
1512         if (n < 4)
1513             quant_matrix = s->inter_matrix;
1514         else
1515             quant_matrix = s->chroma_inter_matrix;
1516
1517         /* special case for the first coef. no need to add a second vlc table */
1518         UPDATE_CACHE(re, &s->gb);
1519         v= SHOW_UBITS(re, &s->gb, 2);
1520         if (v & 2) {
1521             LAST_SKIP_BITS(re, &s->gb, 2);
1522             level= (3*qscale*quant_matrix[0])>>5;
1523             if(v&1)
1524                 level= -level;
1525             block[0] = level;
1526             mismatch ^= level;
1527             i++;
1528         }
1529
1530         /* now quantify & encode AC coefs */
1531         for(;;) {
1532             UPDATE_CACHE(re, &s->gb);
1533             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1534             
1535             if(level == 127){
1536                 break;
1537             } else if(level != 0) {
1538                 i += run;
1539                 j = scantable[i];
1540                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
1541                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1542                 LAST_SKIP_BITS(re, &s->gb, 1);
1543             } else {
1544                 /* escape */
1545                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1546                 UPDATE_CACHE(re, &s->gb);
1547                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1548
1549                 i += run;
1550                 j = scantable[i];
1551                 if(level<0){
1552                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
1553                     level= -level;
1554                 }else{
1555                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
1556                 }
1557             }
1558             if (i > 63){
1559                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1560                 return -1;
1561             }
1562             
1563             mismatch ^= level;
1564             block[j] = level;
1565         }
1566         CLOSE_READER(re, &s->gb);
1567     }
1568     block[63] ^= (mismatch & 1);
1569     
1570     s->block_last_index[n] = i;
1571     return 0;
1572 }
1573
1574 static inline int mpeg2_decode_block_intra(MpegEncContext *s, 
1575                                DCTELEM *block, 
1576                                int n)
1577 {
1578     int level, dc, diff, i, j, run;
1579     int component;
1580     RLTable *rl;
1581     uint8_t * const scantable= s->intra_scantable.permutated;
1582     const uint16_t *quant_matrix;
1583     const int qscale= s->qscale;
1584     int mismatch;
1585
1586     /* DC coef */
1587     if (n < 4){
1588         quant_matrix = s->intra_matrix;
1589         component = 0; 
1590     }else{
1591         quant_matrix = s->chroma_intra_matrix;
1592         component = n - 3;
1593     }
1594     diff = decode_dc(&s->gb, component);
1595     if (diff >= 0xffff)
1596         return -1;
1597     dc = s->last_dc[component];
1598     dc += diff;
1599     s->last_dc[component] = dc;
1600     block[0] = dc << (3 - s->intra_dc_precision);
1601     dprintf("dc=%d\n", block[0]);
1602     mismatch = block[0] ^ 1;
1603     i = 0;
1604     if (s->intra_vlc_format)
1605         rl = &rl_mpeg2;
1606     else
1607         rl = &rl_mpeg1;
1608
1609     {
1610         OPEN_READER(re, &s->gb);    
1611         /* now quantify & encode AC coefs */
1612         for(;;) {
1613             UPDATE_CACHE(re, &s->gb);
1614             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1615             
1616             if(level == 127){
1617                 break;
1618             } else if(level != 0) {
1619                 i += run;
1620                 j = scantable[i];
1621                 level= (level*qscale*quant_matrix[j])>>4;
1622                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1623                 LAST_SKIP_BITS(re, &s->gb, 1);
1624             } else {
1625                 /* escape */
1626                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1627                 UPDATE_CACHE(re, &s->gb);
1628                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1629                 i += run;
1630                 j = scantable[i];
1631                 if(level<0){
1632                     level= (-level*qscale*quant_matrix[j])>>4;
1633                     level= -level;
1634                 }else{
1635                     level= (level*qscale*quant_matrix[j])>>4;
1636                 }
1637             }
1638             if (i > 63){
1639                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1640                 return -1;
1641             }
1642             
1643             mismatch^= level;
1644             block[j] = level;
1645         }
1646         CLOSE_READER(re, &s->gb);
1647     }
1648     block[63]^= mismatch&1;
1649     
1650     s->block_last_index[n] = i;
1651     return 0;
1652 }
1653
1654 typedef struct Mpeg1Context {
1655     MpegEncContext mpeg_enc_ctx;
1656     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1657     int repeat_field; /* true if we must repeat the field */
1658 } Mpeg1Context;
1659
1660 static int mpeg_decode_init(AVCodecContext *avctx)
1661 {
1662     Mpeg1Context *s = avctx->priv_data;
1663     
1664     s->mpeg_enc_ctx.flags= avctx->flags;
1665     common_init(&s->mpeg_enc_ctx);
1666     init_vlcs();
1667
1668     s->mpeg_enc_ctx_allocated = 0;
1669     s->mpeg_enc_ctx.picture_number = 0;
1670     s->repeat_field = 0;
1671     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1672     return 0;
1673 }
1674
1675 /* return the 8 bit start code value and update the search
1676    state. Return -1 if no start code found */
1677 static int find_start_code(uint8_t **pbuf_ptr, uint8_t *buf_end)
1678 {
1679     uint8_t *buf_ptr;
1680     unsigned int state=0xFFFFFFFF, v;
1681     int val;
1682
1683     buf_ptr = *pbuf_ptr;
1684     while (buf_ptr < buf_end) {
1685         v = *buf_ptr++;
1686         if (state == 0x000001) {
1687             state = ((state << 8) | v) & 0xffffff;
1688             val = state;
1689             goto found;
1690         }
1691         state = ((state << 8) | v) & 0xffffff;
1692     }
1693     val = -1;
1694  found:
1695     *pbuf_ptr = buf_ptr;
1696     return val;
1697 }
1698
1699 static int mpeg1_decode_picture(AVCodecContext *avctx, 
1700                                 uint8_t *buf, int buf_size)
1701 {
1702     Mpeg1Context *s1 = avctx->priv_data;
1703     MpegEncContext *s = &s1->mpeg_enc_ctx;
1704     int ref, f_code;
1705
1706     init_get_bits(&s->gb, buf, buf_size*8);
1707
1708     ref = get_bits(&s->gb, 10); /* temporal ref */
1709     s->pict_type = get_bits(&s->gb, 3);
1710     dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1711
1712     skip_bits(&s->gb, 16);
1713     if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1714         s->full_pel[0] = get_bits1(&s->gb);
1715         f_code = get_bits(&s->gb, 3);
1716         if (f_code == 0)
1717             return -1;
1718         s->mpeg_f_code[0][0] = f_code;
1719         s->mpeg_f_code[0][1] = f_code;
1720     }
1721     if (s->pict_type == B_TYPE) {
1722         s->full_pel[1] = get_bits1(&s->gb);
1723         f_code = get_bits(&s->gb, 3);
1724         if (f_code == 0)
1725             return -1;
1726         s->mpeg_f_code[1][0] = f_code;
1727         s->mpeg_f_code[1][1] = f_code;
1728     }
1729     s->current_picture.pict_type= s->pict_type;
1730     s->current_picture.key_frame= s->pict_type == I_TYPE;
1731     
1732     s->y_dc_scale = 8;
1733     s->c_dc_scale = 8;
1734     s->first_slice = 1;
1735     return 0;
1736 }
1737
1738 static void mpeg_decode_sequence_extension(MpegEncContext *s)
1739 {
1740     int horiz_size_ext, vert_size_ext;
1741     int bit_rate_ext, vbv_buf_ext;
1742     int frame_rate_ext_n, frame_rate_ext_d;
1743     int level, profile;
1744     float aspect;
1745
1746     skip_bits(&s->gb, 1); /* profil and level esc*/
1747     profile= get_bits(&s->gb, 3);
1748     level= get_bits(&s->gb, 4);
1749     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1750     skip_bits(&s->gb, 2); /* chroma_format */
1751     horiz_size_ext = get_bits(&s->gb, 2);
1752     vert_size_ext = get_bits(&s->gb, 2);
1753     s->width |= (horiz_size_ext << 12);
1754     s->height |= (vert_size_ext << 12);
1755     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1756     s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1757     skip_bits1(&s->gb); /* marker */
1758     vbv_buf_ext = get_bits(&s->gb, 8);
1759
1760     s->low_delay = get_bits1(&s->gb);
1761     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1762
1763     frame_rate_ext_n = get_bits(&s->gb, 2);
1764     frame_rate_ext_d = get_bits(&s->gb, 5);
1765     av_reduce(
1766         &s->avctx->frame_rate, 
1767         &s->avctx->frame_rate_base, 
1768         frame_rate_tab[s->frame_rate_index] * (frame_rate_ext_n+1),
1769         MPEG1_FRAME_RATE_BASE * (frame_rate_ext_d+1),
1770         1<<30);
1771
1772     dprintf("sequence extension\n");
1773     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1774     s->avctx->sub_id = 2; /* indicates mpeg2 found */
1775
1776     aspect= mpeg2_aspect[s->aspect_ratio_info];
1777     if(aspect>0.0)      s->avctx->aspect_ratio= s->width/(aspect*s->height);
1778     else if(aspect<0.0) s->avctx->aspect_ratio= -1.0/aspect;
1779     
1780     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1781         printf("profile: %d, level: %d \n", profile, level);
1782 }
1783
1784 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1785 {
1786     int i, v, j;
1787
1788     dprintf("matrix extension\n");
1789
1790     if (get_bits1(&s->gb)) {
1791         for(i=0;i<64;i++) {
1792             v = get_bits(&s->gb, 8);
1793             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1794             s->intra_matrix[j] = v;
1795             s->chroma_intra_matrix[j] = v;
1796         }
1797     }
1798     if (get_bits1(&s->gb)) {
1799         for(i=0;i<64;i++) {
1800             v = get_bits(&s->gb, 8);
1801             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1802             s->inter_matrix[j] = v;
1803             s->chroma_inter_matrix[j] = v;
1804         }
1805     }
1806     if (get_bits1(&s->gb)) {
1807         for(i=0;i<64;i++) {
1808             v = get_bits(&s->gb, 8);
1809             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1810             s->chroma_intra_matrix[j] = v;
1811         }
1812     }
1813     if (get_bits1(&s->gb)) {
1814         for(i=0;i<64;i++) {
1815             v = get_bits(&s->gb, 8);
1816             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1817             s->chroma_inter_matrix[j] = v;
1818         }
1819     }
1820 }
1821
1822 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1823 {
1824     s->full_pel[0] = s->full_pel[1] = 0;
1825     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1826     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1827     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1828     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1829     s->intra_dc_precision = get_bits(&s->gb, 2);
1830     s->picture_structure = get_bits(&s->gb, 2);
1831     s->top_field_first = get_bits1(&s->gb);
1832     s->frame_pred_frame_dct = get_bits1(&s->gb);
1833     s->concealment_motion_vectors = get_bits1(&s->gb);
1834     s->q_scale_type = get_bits1(&s->gb);
1835     s->intra_vlc_format = get_bits1(&s->gb);
1836     s->alternate_scan = get_bits1(&s->gb);
1837     s->repeat_first_field = get_bits1(&s->gb);
1838     s->chroma_420_type = get_bits1(&s->gb);
1839     s->progressive_frame = get_bits1(&s->gb);
1840     
1841     if(s->picture_structure == PICT_FRAME)
1842         s->first_field=0;
1843     else{
1844         s->first_field ^= 1;
1845         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1846     }
1847     
1848     if(s->alternate_scan){
1849         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1850         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1851         ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
1852         ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
1853     }else{
1854         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1855         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1856         ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
1857         ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
1858     }
1859     
1860     /* composite display not parsed */
1861     dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1862     dprintf("picture_structure=%d\n", s->picture_structure);
1863     dprintf("top field first=%d\n", s->top_field_first);
1864     dprintf("repeat first field=%d\n", s->repeat_first_field);
1865     dprintf("conceal=%d\n", s->concealment_motion_vectors);
1866     dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1867     dprintf("alternate_scan=%d\n", s->alternate_scan);
1868     dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1869     dprintf("progressive_frame=%d\n", s->progressive_frame);
1870 }
1871
1872 static void mpeg_decode_extension(AVCodecContext *avctx, 
1873                                   uint8_t *buf, int buf_size)
1874 {
1875     Mpeg1Context *s1 = avctx->priv_data;
1876     MpegEncContext *s = &s1->mpeg_enc_ctx;
1877     int ext_type;
1878
1879     init_get_bits(&s->gb, buf, buf_size*8);
1880     
1881     ext_type = get_bits(&s->gb, 4);
1882     switch(ext_type) {
1883     case 0x1:
1884         /* sequence ext */
1885         mpeg_decode_sequence_extension(s);
1886         break;
1887     case 0x3:
1888         /* quant matrix extension */
1889         mpeg_decode_quant_matrix_extension(s);
1890         break;
1891     case 0x8:
1892         /* picture extension */
1893         mpeg_decode_picture_coding_extension(s);
1894         break;
1895     }
1896 }
1897
1898 static void exchange_uv(AVFrame *f){
1899     uint8_t *t= f->data[1];
1900     f->data[1]= f->data[2];
1901     f->data[2]= t;
1902 }
1903
1904 #define DECODE_SLICE_FATAL_ERROR -2
1905 #define DECODE_SLICE_ERROR -1
1906 #define DECODE_SLICE_OK 0
1907
1908 /**
1909  * decodes a slice.
1910  * @return DECODE_SLICE_FATAL_ERROR if a non recoverable error occured<br>
1911  *         DECODE_SLICE_ERROR if the slice is damaged<br>
1912  *         DECODE_SLICE_OK if this slice is ok<br>
1913  */
1914 static int mpeg_decode_slice(AVCodecContext *avctx, 
1915                               AVFrame *pict,
1916                               int start_code,
1917                               uint8_t **buf, int buf_size)
1918 {
1919     Mpeg1Context *s1 = avctx->priv_data;
1920     MpegEncContext *s = &s1->mpeg_enc_ctx;
1921     int ret;
1922     const int field_pic= s->picture_structure != PICT_FRAME;
1923
1924     s->resync_mb_x= s->mb_x = 
1925     s->resync_mb_y= s->mb_y = -1;
1926     
1927     start_code = (start_code - 1) & 0xff;
1928     if (start_code >= s->mb_height){
1929         fprintf(stderr, "slice below image (%d >= %d)\n", start_code, s->mb_height);
1930         return -1;
1931     }
1932     
1933     ff_mpeg1_clean_buffers(s);
1934     s->interlaced_dct = 0;
1935         
1936     /* start frame decoding */
1937     if (s->first_slice) {
1938       if(s->first_field || s->picture_structure==PICT_FRAME){
1939         if(MPV_frame_start(s, avctx) < 0)
1940             return DECODE_SLICE_FATAL_ERROR;
1941
1942         ff_er_frame_start(s);
1943
1944         /* first check if we must repeat the frame */
1945         s->current_picture_ptr->repeat_pict = 0;
1946         if (s->repeat_first_field) {
1947             if (s->progressive_sequence) {
1948                 if (s->top_field_first)
1949                     s->current_picture_ptr->repeat_pict = 4;
1950                 else
1951                     s->current_picture_ptr->repeat_pict = 2;
1952             } else if (s->progressive_frame) {
1953                 s->current_picture_ptr->repeat_pict = 1;
1954             }
1955         }         
1956         //printf("%d\n", s->current_picture_ptr->repeat_pict);
1957
1958         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1959              printf("qp:%d fc:%2d%2d%2d%2d %s %s %s %s dc:%d pstruct:%d fdct:%d cmv:%d qtype:%d ivlc:%d rff:%d %s\n", 
1960                  s->qscale, s->mpeg_f_code[0][0],s->mpeg_f_code[0][1],s->mpeg_f_code[1][0],s->mpeg_f_code[1][1],
1961                  s->pict_type == I_TYPE ? "I" : (s->pict_type == P_TYPE ? "P" : (s->pict_type == B_TYPE ? "B" : "S")), 
1962                  s->progressive_sequence ? "pro" :"", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"", 
1963                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1964                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1965         }
1966       }else{ //second field
1967             int i;
1968             
1969             if(!s->current_picture_ptr){
1970                 fprintf(stderr, "first field missing\n");
1971                 return -1;
1972             }
1973             
1974             for(i=0; i<4; i++){
1975                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1976                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1977                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1978                 } 
1979             }
1980       }
1981 #ifdef HAVE_XVMC
1982 // MPV_frame_start will call this function too,
1983 // but we need to call it on every field
1984       if(s->avctx->xvmc_acceleration)
1985          XVMC_field_start(s,avctx);
1986 #endif
1987     }//fi(s->first_slice)
1988     s->first_slice = 0;
1989
1990     init_get_bits(&s->gb, *buf, buf_size*8);
1991
1992     s->qscale = get_qscale(s);
1993     if(s->qscale == 0){
1994         fprintf(stderr, "qscale == 0\n");
1995         return -1;
1996     }
1997     
1998     /* extra slice info */
1999     while (get_bits1(&s->gb) != 0) {
2000         skip_bits(&s->gb, 8);
2001     }
2002     
2003     s->mb_x=0;
2004
2005     for(;;) {
2006         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
2007         if (code < 0){
2008             fprintf(stderr, "first mb_incr damaged\n");
2009             return -1;
2010         }
2011         if (code >= 33) {
2012             if (code == 33) {
2013                 s->mb_x += 33;
2014             }
2015             /* otherwise, stuffing, nothing to do */
2016         } else {
2017             s->mb_x += code;
2018             break;
2019         }
2020     }
2021     
2022     s->resync_mb_x= s->mb_x;
2023     s->resync_mb_y= s->mb_y = start_code;
2024     s->mb_skip_run= 0;
2025     ff_init_block_index(s);
2026
2027     for(;;) {
2028         s->dsp.clear_blocks(s->block[0]);
2029
2030         ret = mpeg_decode_mb(s, s->block);
2031
2032         dprintf("ret=%d\n", ret);
2033         if (ret < 0)
2034             return -1;
2035             
2036         if(s->motion_val && s->pict_type != B_TYPE){ //note motion_val is normally NULL unless we want to extract the MVs
2037             const int wrap = s->block_wrap[0];
2038             const int xy = s->mb_x*2 + 1 + (s->mb_y*2 +1)*wrap;
2039             int motion_x, motion_y;
2040
2041             if (s->mb_intra) {
2042                 motion_x = motion_y = 0;
2043             }else if (s->mv_type == MV_TYPE_16X16) {
2044                 motion_x = s->mv[0][0][0];
2045                 motion_y = s->mv[0][0][1];
2046             } else /*if (s->mv_type == MV_TYPE_FIELD)*/ {
2047                 motion_x = s->mv[0][0][0] + s->mv[0][1][0];
2048                 motion_y = s->mv[0][0][1] + s->mv[0][1][1];
2049                 motion_x = (motion_x>>1) | (motion_x&1);
2050             }
2051             s->motion_val[xy][0] = motion_x;
2052             s->motion_val[xy][1] = motion_y;
2053             s->motion_val[xy + 1][0] = motion_x;
2054             s->motion_val[xy + 1][1] = motion_y;
2055             s->motion_val[xy + wrap][0] = motion_x;
2056             s->motion_val[xy + wrap][1] = motion_y;
2057             s->motion_val[xy + 1 + wrap][0] = motion_x;
2058             s->motion_val[xy + 1 + wrap][1] = motion_y;
2059         }
2060         
2061         s->dest[0] += 16;
2062         s->dest[1] += 8;
2063         s->dest[2] += 8;
2064
2065         MPV_decode_mb(s, s->block);
2066         
2067         if (++s->mb_x >= s->mb_width) {
2068             if(s->avctx->codec_tag == ff_get_fourcc("VCR2"))
2069                 exchange_uv((AVFrame*)s->current_picture_ptr);
2070
2071             ff_draw_horiz_band(s, 16*s->mb_y, 16);
2072
2073             if(s->avctx->codec_tag == ff_get_fourcc("VCR2"))
2074                 exchange_uv((AVFrame*)s->current_picture_ptr);
2075
2076             s->mb_x = 0;
2077             s->mb_y++;
2078
2079             if(s->mb_y<<field_pic >= s->mb_height){
2080                 int left= s->gb.size_in_bits - get_bits_count(&s->gb);
2081
2082                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)))
2083                    || (avctx->error_resilience >= FF_ER_AGGRESSIVE && left>8)){
2084                     fprintf(stderr, "end missmatch left=%d\n", left);
2085                     return -1;
2086                 }else
2087                     goto eos;
2088             }
2089             
2090             ff_init_block_index(s);
2091         }
2092
2093         /* skip mb handling */
2094         if (s->mb_skip_run == -1) {
2095             /* read again increment */
2096             s->mb_skip_run = 0;
2097             for(;;) {
2098                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
2099                 if (code < 0){
2100                     fprintf(stderr, "mb incr damaged\n");
2101                     return -1;
2102                 }
2103                 if (code >= 33) {
2104                     if (code == 33) {
2105                         s->mb_skip_run += 33;
2106                     }else if(code == 35){
2107                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
2108                             fprintf(stderr, "slice missmatch\n");
2109                             return -1;
2110                         }
2111                         goto eos; /* end of slice */
2112                     }
2113                     /* otherwise, stuffing, nothing to do */
2114                 } else {
2115                     s->mb_skip_run += code;
2116                     break;
2117                 }
2118             }
2119         }
2120     }
2121 eos: // end of slice
2122     *buf += get_bits_count(&s->gb)/8 - 1;
2123 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
2124     return 0;
2125 }
2126
2127 /**
2128  * handles slice ends.
2129  * @return 1 if it seems to be the last slice of 
2130  */
2131 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
2132 {
2133     Mpeg1Context *s1 = avctx->priv_data;
2134     MpegEncContext *s = &s1->mpeg_enc_ctx;
2135        
2136     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
2137         return 0;
2138
2139 #ifdef HAVE_XVMC
2140     if(s->avctx->xvmc_acceleration)
2141         XVMC_field_end(s);
2142 #endif
2143     /* end of slice reached */
2144     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
2145         /* end of image */
2146
2147         if(s->codec_id == CODEC_ID_MPEG2VIDEO){
2148             s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
2149         }else
2150             s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG1;
2151
2152         ff_er_frame_end(s);
2153
2154         MPV_frame_end(s);
2155
2156         if (s->pict_type == B_TYPE || s->low_delay) {
2157             *pict= *(AVFrame*)s->current_picture_ptr;
2158             ff_print_debug_info(s, s->current_picture_ptr);
2159         } else {
2160             s->picture_number++;
2161             /* latency of 1 frame for I and P frames */
2162             /* XXX: use another variable than picture_number */
2163             if (s->last_picture_ptr != NULL) {
2164                 *pict= *(AVFrame*)s->last_picture_ptr;
2165                  ff_print_debug_info(s, s->last_picture_ptr);
2166             }
2167         }
2168         if(s->avctx->codec_tag == ff_get_fourcc("VCR2"))
2169             exchange_uv(pict);
2170
2171         return 1;
2172     } else {
2173         return 0;
2174     }
2175 }
2176
2177 static int mpeg1_decode_sequence(AVCodecContext *avctx, 
2178                                  uint8_t *buf, int buf_size)
2179 {
2180     Mpeg1Context *s1 = avctx->priv_data;
2181     MpegEncContext *s = &s1->mpeg_enc_ctx;
2182     int width, height, i, v, j;
2183     float aspect;
2184
2185     init_get_bits(&s->gb, buf, buf_size*8);
2186
2187     width = get_bits(&s->gb, 12);
2188     height = get_bits(&s->gb, 12);
2189     s->aspect_ratio_info= get_bits(&s->gb, 4);
2190     if(s->codec_id == CODEC_ID_MPEG1VIDEO){
2191         aspect= mpeg1_aspect[s->aspect_ratio_info];
2192         if(aspect!=0.0) avctx->aspect_ratio= width/(aspect*height);
2193     }
2194
2195     s->frame_rate_index = get_bits(&s->gb, 4);
2196     if (s->frame_rate_index == 0)
2197         return -1;
2198     s->bit_rate = get_bits(&s->gb, 18) * 400;
2199     if (get_bits1(&s->gb) == 0) /* marker */
2200         return -1;
2201     if (width <= 0 || height <= 0 ||
2202         (width % 2) != 0 || (height % 2) != 0)
2203         return -1;
2204     if (width != s->width ||
2205         height != s->height) {
2206         /* start new mpeg1 context decoding */
2207         s->out_format = FMT_MPEG1;
2208         if (s1->mpeg_enc_ctx_allocated) {
2209             MPV_common_end(s);
2210         }
2211         s->width = width;
2212         s->height = height;
2213         avctx->has_b_frames= 1;
2214         s->avctx = avctx;
2215         avctx->width = width;
2216         avctx->height = height;
2217         av_reduce(
2218             &avctx->frame_rate, 
2219             &avctx->frame_rate_base,
2220             frame_rate_tab[s->frame_rate_index],
2221             MPEG1_FRAME_RATE_BASE, //FIXME store in allready reduced form 
2222             1<<30
2223             );
2224         avctx->bit_rate = s->bit_rate;
2225         
2226         //get_format() or set_video(width,height,aspect,pix_fmt);
2227         //until then pix_fmt may be changed right after codec init
2228         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT )
2229             avctx->idct_algo = FF_IDCT_SIMPLE;
2230
2231         if (MPV_common_init(s) < 0)
2232             return -1;
2233         s1->mpeg_enc_ctx_allocated = 1;
2234     }
2235
2236     skip_bits(&s->gb, 10); /* vbv_buffer_size */
2237     skip_bits(&s->gb, 1);
2238
2239     /* get matrix */
2240     if (get_bits1(&s->gb)) {
2241         for(i=0;i<64;i++) {
2242             v = get_bits(&s->gb, 8);
2243             j = s->intra_scantable.permutated[i];
2244             s->intra_matrix[j] = v;
2245             s->chroma_intra_matrix[j] = v;
2246         }
2247 #ifdef DEBUG
2248         dprintf("intra matrix present\n");
2249         for(i=0;i<64;i++)
2250             dprintf(" %d", s->intra_matrix[s->intra_scantable.permutated[i]]);
2251         printf("\n");
2252 #endif
2253     } else {
2254         for(i=0;i<64;i++) {
2255             int j= s->dsp.idct_permutation[i];
2256             v = ff_mpeg1_default_intra_matrix[i];
2257             s->intra_matrix[j] = v;
2258             s->chroma_intra_matrix[j] = v;
2259         }
2260     }
2261     if (get_bits1(&s->gb)) {
2262         for(i=0;i<64;i++) {
2263             v = get_bits(&s->gb, 8);
2264             j = s->intra_scantable.permutated[i];
2265             s->inter_matrix[j] = v;
2266             s->chroma_inter_matrix[j] = v;
2267         }
2268 #ifdef DEBUG
2269         dprintf("non intra matrix present\n");
2270         for(i=0;i<64;i++)
2271             dprintf(" %d", s->inter_matrix[s->intra_scantable.permutated[i]]);
2272         printf("\n");
2273 #endif
2274     } else {
2275         for(i=0;i<64;i++) {
2276             int j= s->dsp.idct_permutation[i];
2277             v = ff_mpeg1_default_non_intra_matrix[i];
2278             s->inter_matrix[j] = v;
2279             s->chroma_inter_matrix[j] = v;
2280         }
2281     }
2282
2283     /* we set mpeg2 parameters so that it emulates mpeg1 */
2284     s->progressive_sequence = 1;
2285     s->progressive_frame = 1;
2286     s->picture_structure = PICT_FRAME;
2287     s->frame_pred_frame_dct = 1;
2288     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2289     avctx->sub_id = 1; /* indicates mpeg1 */
2290     return 0;
2291 }
2292
2293 static int vcr2_init_sequence(AVCodecContext *avctx)
2294 {
2295     Mpeg1Context *s1 = avctx->priv_data;
2296     MpegEncContext *s = &s1->mpeg_enc_ctx;
2297     int i, v;
2298
2299     /* start new mpeg1 context decoding */
2300     s->out_format = FMT_MPEG1;
2301     if (s1->mpeg_enc_ctx_allocated) {
2302         MPV_common_end(s);
2303     }
2304     s->width = avctx->width;
2305     s->height = avctx->height;
2306     avctx->has_b_frames= 0; //true?
2307     s->low_delay= 1;
2308     s->avctx = avctx;
2309
2310     //get_format() or set_video(width,height,aspect,pix_fmt);
2311     //until then pix_fmt may be changed right after codec init
2312     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT )
2313         avctx->idct_algo = FF_IDCT_SIMPLE;
2314     
2315     if (MPV_common_init(s) < 0)
2316         return -1;
2317     s1->mpeg_enc_ctx_allocated = 1;
2318
2319     for(i=0;i<64;i++) {
2320         int j= s->dsp.idct_permutation[i];
2321         v = ff_mpeg1_default_intra_matrix[i];
2322         s->intra_matrix[j] = v;
2323         s->chroma_intra_matrix[j] = v;
2324
2325         v = ff_mpeg1_default_non_intra_matrix[i];
2326         s->inter_matrix[j] = v;
2327         s->chroma_inter_matrix[j] = v;
2328     }
2329
2330     s->progressive_sequence = 1;
2331     s->progressive_frame = 1;
2332     s->picture_structure = PICT_FRAME;
2333     s->frame_pred_frame_dct = 1;
2334     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2335     avctx->sub_id = 2; /* indicates mpeg2 */
2336     return 0;
2337 }
2338
2339
2340 static void mpeg_decode_user_data(AVCodecContext *avctx, 
2341                                   const uint8_t *buf, int buf_size)
2342 {
2343     const uint8_t *p;
2344     int len, flags;
2345     p = buf;
2346     len = buf_size;
2347
2348     /* we parse the DTG active format information */
2349     if (len >= 5 &&
2350         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2351         flags = p[4];
2352         p += 5;
2353         len -= 5;
2354         if (flags & 0x80) {
2355             /* skip event id */
2356             if (len < 2)
2357                 return;
2358             p += 2;
2359             len -= 2;
2360         }
2361         if (flags & 0x40) {
2362             if (len < 1)
2363                 return;
2364             avctx->dtg_active_format = p[0] & 0x0f;
2365         }
2366     }
2367 }
2368
2369 /**
2370  * finds the end of the current frame in the bitstream.
2371  * @return the position of the first byte of the next frame, or -1
2372  */
2373 static int mpeg1_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
2374     ParseContext *pc= &s->parse_context;
2375     int i;
2376     uint32_t state;
2377     
2378     state= pc->state;
2379     
2380     i=0;
2381     if(!pc->frame_start_found){
2382         for(i=0; i<buf_size; i++){
2383             state= (state<<8) | buf[i];
2384             if(state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2385                 i++;
2386                 pc->frame_start_found=1;
2387                 break;
2388             }
2389         }
2390     }
2391     
2392     if(pc->frame_start_found){
2393         for(; i<buf_size; i++){
2394             state= (state<<8) | buf[i];
2395             if((state&0xFFFFFF00) == 0x100){
2396                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2397                     pc->frame_start_found=0;
2398                     pc->state=-1; 
2399                     return i-3;
2400                 }
2401             }
2402         }
2403     }        
2404     pc->state= state;
2405     return END_NOT_FOUND;
2406 }
2407
2408 /* handle buffering and image synchronisation */
2409 static int mpeg_decode_frame(AVCodecContext *avctx, 
2410                              void *data, int *data_size,
2411                              uint8_t *buf, int buf_size)
2412 {
2413     Mpeg1Context *s = avctx->priv_data;
2414     uint8_t *buf_end, *buf_ptr;
2415     int ret, start_code, input_size;
2416     AVFrame *picture = data;
2417     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2418     dprintf("fill_buffer\n");
2419
2420     *data_size = 0;
2421
2422     /* special case for last picture */
2423     if (buf_size == 0 && s2->low_delay==0 && s2->next_picture_ptr) {
2424         *picture= *(AVFrame*)s2->next_picture_ptr;
2425         s2->next_picture_ptr= NULL;
2426
2427         *data_size = sizeof(AVFrame);
2428         return 0;
2429     }
2430
2431     if(s2->flags&CODEC_FLAG_TRUNCATED){
2432         int next= mpeg1_find_frame_end(s2, buf, buf_size);
2433         
2434         if( ff_combine_frame(s2, next, &buf, &buf_size) < 0 )
2435             return buf_size;
2436     }    
2437     
2438     buf_ptr = buf;
2439     buf_end = buf + buf_size;
2440
2441 #if 0    
2442     if (s->repeat_field % 2 == 1) { 
2443         s->repeat_field++;
2444         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2445         //        s2->picture_number, s->repeat_field);
2446         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2447             *data_size = sizeof(AVPicture);
2448             goto the_end;
2449         }
2450     }
2451 #endif
2452
2453     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == ff_get_fourcc("VCR2"))
2454         vcr2_init_sequence(avctx);
2455
2456     for(;;) {
2457         /* find start next code */
2458         start_code = find_start_code(&buf_ptr, buf_end);
2459         if (start_code < 0){
2460             if(s2->pict_type != B_TYPE || avctx->hurry_up==0){
2461                 if (slice_end(avctx, picture)) {
2462                     if(s2->last_picture_ptr) //FIXME merge with the stuff in mpeg_decode_slice
2463                         *data_size = sizeof(AVPicture);
2464                 }
2465             }
2466             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2467         }
2468         
2469         input_size = buf_end - buf_ptr;
2470
2471         if(avctx->debug & FF_DEBUG_STARTCODE){
2472             printf("%3X at %d left %d\n", start_code, buf_ptr-buf, input_size);
2473         }
2474
2475                 /* prepare data for next start code */
2476                 switch(start_code) {
2477                 case SEQ_START_CODE:
2478                     mpeg1_decode_sequence(avctx, buf_ptr, 
2479                                           input_size);
2480                     break;
2481                             
2482                 case PICTURE_START_CODE:
2483                     /* we have a complete image : we try to decompress it */
2484                     mpeg1_decode_picture(avctx, 
2485                                          buf_ptr, input_size);
2486                     break;
2487                 case EXT_START_CODE:
2488                     mpeg_decode_extension(avctx,
2489                                           buf_ptr, input_size);
2490                     break;
2491                 case USER_START_CODE:
2492                     mpeg_decode_user_data(avctx, 
2493                                           buf_ptr, input_size);
2494                     break;
2495                 case GOP_START_CODE:
2496                     s2->first_field=0;
2497                     break;
2498                 default:
2499                     if (start_code >= SLICE_MIN_START_CODE &&
2500                         start_code <= SLICE_MAX_START_CODE) {
2501                         
2502                         /* skip b frames if we dont have reference frames */
2503                         if(s2->last_picture_ptr==NULL && s2->pict_type==B_TYPE) break;
2504                         /* skip b frames if we are in a hurry */
2505                         if(avctx->hurry_up && s2->pict_type==B_TYPE) break;
2506                         /* skip everything if we are in a hurry>=5 */
2507                         if(avctx->hurry_up>=5) break;
2508                         
2509                         if (!s->mpeg_enc_ctx_allocated) break;
2510
2511                         ret = mpeg_decode_slice(avctx, picture,
2512                                                 start_code, &buf_ptr, input_size);
2513                         emms_c();
2514
2515                         if(ret < 0){
2516                             if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2517                                 ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x, s2->mb_y, AC_ERROR|DC_ERROR|MV_ERROR);
2518                             if(ret==DECODE_SLICE_FATAL_ERROR) return -1;
2519                         }else{
2520                             ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x-1, s2->mb_y, AC_END|DC_END|MV_END);
2521                         }
2522                     }
2523                     break;
2524                 }
2525     }
2526 }
2527
2528 static int mpeg_decode_end(AVCodecContext *avctx)
2529 {
2530     Mpeg1Context *s = avctx->priv_data;
2531
2532     if (s->mpeg_enc_ctx_allocated)
2533         MPV_common_end(&s->mpeg_enc_ctx);
2534     return 0;
2535 }
2536
2537 AVCodec mpeg1video_decoder = {
2538     "mpeg1video",
2539     CODEC_TYPE_VIDEO,
2540     CODEC_ID_MPEG1VIDEO,
2541     sizeof(Mpeg1Context),
2542     mpeg_decode_init,
2543     NULL,
2544     mpeg_decode_end,
2545     mpeg_decode_frame,
2546     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
2547     .flush= ff_mpeg_flush,
2548 };
2549
2550 AVCodec mpeg2video_decoder = {
2551     "mpeg2video",
2552     CODEC_TYPE_VIDEO,
2553     CODEC_ID_MPEG2VIDEO,
2554     sizeof(Mpeg1Context),
2555     mpeg_decode_init,
2556     NULL,
2557     mpeg_decode_end,
2558     mpeg_decode_frame,
2559     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
2560     .flush= ff_mpeg_flush,
2561 };
2562
2563 #ifdef HAVE_XVMC
2564 static int mpeg_mc_decode_init(AVCodecContext *avctx){
2565     Mpeg1Context *s;
2566
2567     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2568         return -1;
2569     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) )
2570         dprintf("mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2571
2572     mpeg_decode_init(avctx);
2573     s = avctx->priv_data;
2574
2575     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2576     avctx->xvmc_acceleration = 1;
2577
2578     return 0;
2579 }
2580
2581 AVCodec mpeg_xvmc_decoder = {
2582     "mpegvideo_xvmc",
2583     CODEC_TYPE_VIDEO,
2584     CODEC_ID_MPEG2VIDEO_XVMC,
2585     sizeof(Mpeg1Context),
2586     mpeg_mc_decode_init,
2587     NULL,
2588     mpeg_decode_end,
2589     mpeg_decode_frame,
2590     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
2591 };
2592
2593 #endif
2594
2595 /* this is ugly i know, but the alternative is too make 
2596    hundreds of vars global and prefix them with ff_mpeg1_
2597    which is far uglier. */
2598 #include "mdec.c"