field pic decoding cleanup
[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 codec / MPEG2 decoder.
23  */
24  
25 //#define DEBUG
26 #include "avcodec.h"
27 #include "dsputil.h"
28 #include "mpegvideo.h"
29
30 #include "mpeg12data.h"
31
32 #if 1
33 #define PRINT_QP(a, b) {}
34 #else
35 #define PRINT_QP(a, b) printf(a, b)
36 #endif
37
38 /* Start codes. */
39 #define SEQ_END_CODE            0x000001b7
40 #define SEQ_START_CODE          0x000001b3
41 #define GOP_START_CODE          0x000001b8
42 #define PICTURE_START_CODE      0x00000100
43 #define SLICE_MIN_START_CODE    0x00000101
44 #define SLICE_MAX_START_CODE    0x000001af
45 #define EXT_START_CODE          0x000001b5
46 #define USER_START_CODE         0x000001b2
47
48 #define DC_VLC_BITS 9
49 #define MV_VLC_BITS 9
50 #define MBINCR_VLC_BITS 9
51 #define MB_PAT_VLC_BITS 9
52 #define MB_PTYPE_VLC_BITS 6
53 #define MB_BTYPE_VLC_BITS 6
54 #define TEX_VLC_BITS 9
55
56 static void mpeg1_encode_block(MpegEncContext *s, 
57                          DCTELEM *block, 
58                          int component);
59 static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code);    // RAL: f_code parameter added
60 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
61 static inline int mpeg1_decode_block_inter(MpegEncContext *s, 
62                               DCTELEM *block, 
63                               int n);
64 static inline int mpeg1_decode_block_intra(MpegEncContext *s, 
65                               DCTELEM *block, 
66                               int n);
67 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s, 
68                                         DCTELEM *block, 
69                                         int n);
70 static inline int mpeg2_decode_block_intra(MpegEncContext *s, 
71                                     DCTELEM *block, 
72                                     int n);
73 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
74
75 #ifdef CONFIG_ENCODERS
76 static uint16_t mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
77 static uint8_t fcode_tab[MAX_MV*2+1];
78
79 static uint32_t uni_mpeg1_ac_vlc_bits[64*64*2];
80 static uint8_t  uni_mpeg1_ac_vlc_len [64*64*2];
81 #endif
82
83 static inline int get_bits_diff(MpegEncContext *s){
84     int bits,ret;
85     
86     bits= get_bit_count(&s->pb);
87     ret= bits - s->last_bits;
88     s->last_bits=bits;
89     
90     return ret;
91 }
92
93 static void init_2d_vlc_rl(RLTable *rl)
94 {
95     int i;
96     
97     init_vlc(&rl->vlc, TEX_VLC_BITS, rl->n + 2, 
98              &rl->table_vlc[0][1], 4, 2,
99              &rl->table_vlc[0][0], 4, 2);
100
101     
102     rl->rl_vlc[0]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
103     for(i=0; i<rl->vlc.table_size; i++){
104         int code= rl->vlc.table[i][0];
105         int len = rl->vlc.table[i][1];
106         int level, run;
107     
108         if(len==0){ // illegal code
109             run= 65;
110             level= MAX_LEVEL;
111         }else if(len<0){ //more bits needed
112             run= 0;
113             level= code;
114         }else{
115             if(code==rl->n){ //esc
116                 run= 65;
117                 level= 0;
118             }else if(code==rl->n+1){ //eob
119                 run= 0;
120                 level= 127;
121             }else{
122                 run=   rl->table_run  [code] + 1;
123                 level= rl->table_level[code];
124             }
125         }
126         rl->rl_vlc[0][i].len= len;
127         rl->rl_vlc[0][i].level= level;
128         rl->rl_vlc[0][i].run= run;
129     }
130 }
131
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         
195         if(aspect_ratio==0.0) aspect_ratio= s->width / (float)s->height; //pixel aspect 1:1 (VGA)
196         
197         if (s->current_picture.key_frame) {
198             /* mpeg1 header repeated every gop */
199             put_header(s, SEQ_START_CODE);
200             
201             /* search closest frame rate */
202             {
203                 int i, dmin, d;
204                 s->frame_rate_index = 0;
205                 dmin = 0x7fffffff;
206                 for(i=1;i<14;i++) {
207                     if(s->avctx->strict_std_compliance >= 0 && i>=9) break;
208                      
209                     d = abs(MPEG1_FRAME_RATE_BASE*(int64_t)s->avctx->frame_rate/s->avctx->frame_rate_base - frame_rate_tab[i]);
210                     if (d < dmin) {
211                         dmin = d;
212                         s->frame_rate_index = i;
213                     }
214                 }
215             }
216  
217             put_bits(&s->pb, 12, s->width);
218             put_bits(&s->pb, 12, s->height);
219             
220             for(i=1; i<15; i++){
221                 float error= mpeg1_aspect[i] - s->width/(s->height*aspect_ratio);
222                 error= ABS(error);
223                 
224                 if(error < best_aspect_error){
225                     best_aspect_error= error;
226                     s->aspect_ratio_info= i;
227                 }
228             }
229             
230             put_bits(&s->pb, 4, s->aspect_ratio_info);
231             put_bits(&s->pb, 4, s->frame_rate_index);
232             v = (s->bit_rate + 399) / 400;
233             if (v > 0x3ffff)
234                 v = 0x3ffff;
235             put_bits(&s->pb, 18, v);
236             put_bits(&s->pb, 1, 1); /* marker */
237
238             if(s->avctx->rc_buffer_size)
239                 vbv_buffer_size = s->avctx->rc_buffer_size;
240             else
241                 /* VBV calculation: Scaled so that a VCD has the proper VBV size of 40 kilobytes */
242                 vbv_buffer_size = (( 20 * s->bit_rate) / (1151929 / 2)) * 8 * 1024;      
243             put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384); 
244             put_bits(&s->pb, 1, 1); /* constrained parameter flag */
245             put_bits(&s->pb, 1, 0); /* no custom intra matrix */
246             put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
247
248             put_header(s, GOP_START_CODE);
249             put_bits(&s->pb, 1, 0); /* do drop frame */
250             /* time code : we must convert from the real frame rate to a
251                fake mpeg frame rate in case of low frame rate */
252             fps = frame_rate_tab[s->frame_rate_index];
253             time_code = (int64_t)s->fake_picture_number * MPEG1_FRAME_RATE_BASE;
254             s->gop_picture_number = s->fake_picture_number;
255             put_bits(&s->pb, 5, (uint32_t)((time_code / (fps * 3600)) % 24));
256             put_bits(&s->pb, 6, (uint32_t)((time_code / (fps * 60)) % 60));
257             put_bits(&s->pb, 1, 1);
258             put_bits(&s->pb, 6, (uint32_t)((time_code / fps) % 60));
259             put_bits(&s->pb, 6, (uint32_t)((time_code % fps) / MPEG1_FRAME_RATE_BASE));
260             put_bits(&s->pb, 1, 1); /* closed gop */
261             put_bits(&s->pb, 1, 0); /* broken link */
262         }
263
264         if (s->avctx->frame_rate < (24 * s->avctx->frame_rate_base) && s->picture_number > 0) {
265             /* insert empty P pictures to slow down to the desired
266                frame rate. Each fake pictures takes about 20 bytes */
267             fps = frame_rate_tab[s->frame_rate_index];
268             n = av_rescale((int64_t)s->picture_number * s->avctx->frame_rate_base, fps, s->avctx->frame_rate) / MPEG1_FRAME_RATE_BASE - 1;
269             while (s->fake_picture_number < n) {
270                 mpeg1_skip_picture(s, s->fake_picture_number - 
271                                    s->gop_picture_number); 
272                 s->fake_picture_number++;
273             }
274
275         }
276 }
277
278
279 /* insert a fake P picture */
280 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
281 {
282     unsigned int mb_incr;
283
284     /* mpeg1 picture header */
285     put_header(s, PICTURE_START_CODE);
286     /* temporal reference */
287     put_bits(&s->pb, 10, pict_num & 0x3ff); 
288     
289     put_bits(&s->pb, 3, P_TYPE);
290     put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
291     
292     put_bits(&s->pb, 1, 1); /* integer coordinates */
293     put_bits(&s->pb, 3, 1); /* forward_f_code */
294     
295     put_bits(&s->pb, 1, 0); /* extra bit picture */
296     
297     /* only one slice */
298     put_header(s, SLICE_MIN_START_CODE);
299     put_bits(&s->pb, 5, 1); /* quantizer scale */
300     put_bits(&s->pb, 1, 0); /* slice extra information */
301     
302     mb_incr = 1;
303     put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
304              mbAddrIncrTable[mb_incr - 1][0]);
305     
306     /* empty macroblock */
307     put_bits(&s->pb, 3, 1); /* motion only */
308     
309     /* zero motion x & y */
310     put_bits(&s->pb, 1, 1); 
311     put_bits(&s->pb, 1, 1); 
312
313     /* output a number of empty slice */
314     mb_incr = s->mb_width * s->mb_height - 1;
315     while (mb_incr > 33) {
316         put_bits(&s->pb, 11, 0x008);
317         mb_incr -= 33;
318     }
319     put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
320              mbAddrIncrTable[mb_incr - 1][0]);
321     
322     /* empty macroblock */
323     put_bits(&s->pb, 3, 1); /* motion only */
324     
325     /* zero motion x & y */
326     put_bits(&s->pb, 1, 1); 
327     put_bits(&s->pb, 1, 1); 
328 }
329
330 static void common_init(MpegEncContext *s)
331 {
332     s->y_dc_scale_table=
333     s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
334 }
335
336 #ifdef CONFIG_ENCODERS
337 void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
338 {
339     mpeg1_encode_sequence_header(s);
340
341     /* mpeg1 picture header */
342     put_header(s, PICTURE_START_CODE);
343     /* temporal reference */
344
345     // RAL: s->picture_number instead of s->fake_picture_number
346     put_bits(&s->pb, 10, (s->picture_number - 
347                           s->gop_picture_number) & 0x3ff); 
348     s->fake_picture_number++;
349     
350     put_bits(&s->pb, 3, s->pict_type);
351     put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
352     
353     // RAL: Forward f_code also needed for B frames
354     if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
355         put_bits(&s->pb, 1, 0); /* half pel coordinates */
356         put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
357     }
358     
359     // RAL: Backward f_code necessary for B frames
360     if (s->pict_type == B_TYPE) {
361         put_bits(&s->pb, 1, 0); /* half pel coordinates */
362         put_bits(&s->pb, 3, s->b_code); /* backward_f_code */
363         }
364
365     put_bits(&s->pb, 1, 0); /* extra bit picture */
366     
367     /* only one slice */
368     put_header(s, SLICE_MIN_START_CODE);
369     put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
370     put_bits(&s->pb, 1, 0); /* slice extra information */
371 }
372
373 void mpeg1_encode_mb(MpegEncContext *s,
374                      DCTELEM block[6][64],
375                      int motion_x, int motion_y)
376 {
377     int mb_incr, i, cbp, mb_x, mb_y;
378
379     mb_x = s->mb_x;
380     mb_y = s->mb_y;
381
382     /* compute cbp */
383     cbp = 0;
384     for(i=0;i<6;i++) {
385         if (s->block_last_index[i] >= 0)
386             cbp |= 1 << (5 - i);
387     }
388
389     // RAL: Skipped macroblocks for B frames...
390     if (cbp == 0 && (!((mb_x | mb_y) == 0 || (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1))) && 
391         ((s->pict_type == P_TYPE && (motion_x | motion_y) == 0) ||
392         (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) |
393         ((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))) {
394         s->mb_incr++;
395         s->qscale -= s->dquant;
396         s->skip_count++;
397         s->misc_bits++;
398         s->last_bits++;
399     } else {
400         /* output mb incr */
401         mb_incr = s->mb_incr;
402
403         while (mb_incr > 33) {
404             put_bits(&s->pb, 11, 0x008);
405             mb_incr -= 33;
406         }
407         put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1], 
408                  mbAddrIncrTable[mb_incr - 1][0]);
409         
410         if (s->pict_type == I_TYPE) {
411             if(s->dquant && cbp){
412                 put_bits(&s->pb, 2, 1); /* macroblock_type : macroblock_quant = 1 */
413                 put_bits(&s->pb, 5, s->qscale);
414             }else{
415                 put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
416                 s->qscale -= s->dquant;
417             }
418             s->misc_bits+= get_bits_diff(s);
419             s->i_count++;
420         } else if (s->mb_intra) {
421             if(s->dquant && cbp){
422                 put_bits(&s->pb, 6, 0x01);
423                 put_bits(&s->pb, 5, s->qscale);
424             }else{
425                 put_bits(&s->pb, 5, 0x03);
426                 s->qscale -= s->dquant;
427             }
428             s->misc_bits+= get_bits_diff(s);
429             s->i_count++;
430             s->last_mv[0][0][0] = 
431             s->last_mv[0][0][1] = 0;
432         } else if (s->pict_type == P_TYPE) { 
433                 if (cbp != 0) {
434                     if (motion_x == 0 && motion_y == 0) {
435                         if(s->dquant){
436                             put_bits(&s->pb, 5, 1); /* macroblock_pattern & quant */
437                             put_bits(&s->pb, 5, s->qscale);
438                         }else{
439                             put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
440                         }
441                         s->misc_bits+= get_bits_diff(s);
442                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
443                     } else {
444                         if(s->dquant){
445                             put_bits(&s->pb, 5, 2); /* motion + cbp */
446                             put_bits(&s->pb, 5, s->qscale);
447                         }else{
448                             put_bits(&s->pb, 1, 1); /* motion + cbp */
449                         }
450                         s->misc_bits+= get_bits_diff(s);
451                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);    // RAL: f_code parameter added
452                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);    // RAL: f_code parameter added
453                         s->mv_bits+= get_bits_diff(s);
454                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
455                     }
456                 } else {
457                     put_bits(&s->pb, 3, 1); /* motion only */
458                     mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);    // RAL: f_code parameter added
459                     mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);    // RAL: f_code parameter added
460                     s->qscale -= s->dquant;
461                     s->mv_bits+= get_bits_diff(s);
462                 }
463                 s->f_count++;
464         } else
465             {    // RAL: All the following bloc added for B frames:
466                 if (cbp != 0)
467                     {    // With coded bloc pattern
468                     if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
469                         {    // Bi-directional motion
470                         if (s->dquant)
471                             {    // With QScale
472                             put_bits(&s->pb, 5, 2);
473                             put_bits(&s->pb, 5, s->qscale);
474                             }
475                         else    // Without QScale
476                             put_bits(&s->pb, 2, 3);
477                         s->misc_bits += get_bits_diff(s);
478                         mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
479                         mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
480                         mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
481                         mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
482                         s->b_count++;
483                         s->f_count++;
484                         s->mv_bits += get_bits_diff(s);
485                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
486                         }
487                     else if (s->mv_dir == MV_DIR_BACKWARD)
488                         {    // Backward motion
489                         if (s->dquant)
490                             {    // With QScale
491                             put_bits(&s->pb, 6, 2);
492                             put_bits(&s->pb, 5, s->qscale);
493                             }
494                         else    // Without QScale
495                             put_bits(&s->pb, 3, 3);
496                         s->misc_bits += get_bits_diff(s);
497                         mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code); 
498                         mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code); 
499                         s->b_count++;
500                         s->mv_bits += get_bits_diff(s);
501                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
502                         }
503                     else if (s->mv_dir == MV_DIR_FORWARD)
504                         {    // Forward motion
505                         if (s->dquant)
506                             {    // With QScale
507                             put_bits(&s->pb, 6, 3);
508                             put_bits(&s->pb, 5, s->qscale);
509                             }
510                         else    // Without QScale
511                             put_bits(&s->pb, 4, 3);
512                         s->misc_bits += get_bits_diff(s);
513                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code); 
514                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code); 
515                         s->f_count++;
516                         s->mv_bits += get_bits_diff(s);
517                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
518                         }
519                     }
520                 else
521                     {    // No coded bloc pattern
522                     if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
523                         {    // Bi-directional motion 
524                         put_bits(&s->pb, 2, 2); /* backward & forward motion */
525                         mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
526                         mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
527                         mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
528                         mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
529                         s->b_count++;
530                         s->f_count++;
531                         }
532                     else if (s->mv_dir == MV_DIR_BACKWARD)
533                         {    // Backward motion
534                         put_bits(&s->pb, 3, 2); /* backward motion only */
535                         mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code); 
536                         mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code); 
537                         s->b_count++;
538                         }
539                     else if (s->mv_dir == MV_DIR_FORWARD)
540                         {    // Forward motion
541                         put_bits(&s->pb, 4, 2); /* forward motion only */
542                         mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code); 
543                         mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code); 
544                         s->f_count++;
545                         }
546                     s->qscale -= s->dquant;
547                     s->mv_bits += get_bits_diff(s);
548                     }
549             // End of bloc from RAL
550             }
551         for(i=0;i<6;i++) {
552             if (cbp & (1 << (5 - i))) {
553                 mpeg1_encode_block(s, block[i], i);
554             }
555         }
556         s->mb_incr = 1;
557         if(s->mb_intra)
558             s->i_tex_bits+= get_bits_diff(s);
559         else
560             s->p_tex_bits+= get_bits_diff(s);
561     }
562
563     // RAL: By this:
564     if (s->mv_dir & MV_DIR_FORWARD)
565         {
566         s->last_mv[0][0][0]= s->mv[0][0][0];
567         s->last_mv[0][0][1]= s->mv[0][0][1];
568         }
569     if (s->mv_dir & MV_DIR_BACKWARD)
570         {
571         s->last_mv[1][0][0]= s->mv[1][0][0];
572         s->last_mv[1][0][1]= s->mv[1][0][1];
573         }
574 }
575
576 // RAL: Parameter added: f_or_b_code
577 static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code)
578 {
579     int code, bit_size, l, m, bits, range, sign;
580
581     if (val == 0) {
582         /* zero vector */
583         code = 0;
584         put_bits(&s->pb,
585                  mbMotionVectorTable[0][1], 
586                  mbMotionVectorTable[0][0]); 
587     } else {
588         bit_size = f_or_b_code - 1;
589         range = 1 << bit_size;
590         /* modulo encoding */
591         l = 16 * range;
592         m = 2 * l;
593         if (val < -l) {
594             val += m;
595         } else if (val >= l) {
596             val -= m;
597         }
598
599         if (val >= 0) {
600             val--;
601             code = (val >> bit_size) + 1;
602             bits = val & (range - 1);
603             sign = 0;
604         } else {
605             val = -val;
606             val--;
607             code = (val >> bit_size) + 1;
608             bits = val & (range - 1);
609             sign = 1;
610         }
611
612         assert(code > 0 && code <= 16);
613
614         put_bits(&s->pb,
615                  mbMotionVectorTable[code][1], 
616                  mbMotionVectorTable[code][0]); 
617
618         put_bits(&s->pb, 1, sign);
619         if (bit_size > 0) {
620             put_bits(&s->pb, bit_size, bits);
621         }
622     }
623 }
624
625 void ff_mpeg1_encode_init(MpegEncContext *s)
626 {
627     static int done=0;
628
629     common_init(s);
630
631     if(!done){
632         int f_code;
633         int mv;
634         int i;
635
636         done=1;
637         init_rl(&rl_mpeg1);
638
639         for(i=0; i<64; i++)
640         {
641                 mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
642                 mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
643         }
644         
645         init_uni_ac_vlc(&rl_mpeg1, uni_mpeg1_ac_vlc_bits, uni_mpeg1_ac_vlc_len);
646
647         /* build unified dc encoding tables */
648         for(i=-255; i<256; i++)
649         {
650                 int adiff, index;
651                 int bits, code;
652                 int diff=i;
653
654                 adiff = ABS(diff);
655                 if(diff<0) diff--;
656                 index = vlc_dc_table[adiff];
657
658                 bits= vlc_dc_lum_bits[index] + index;
659                 code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
660                 mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
661                 
662                 bits= vlc_dc_chroma_bits[index] + index;
663                 code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
664                 mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
665         }
666
667         for(f_code=1; f_code<=MAX_FCODE; f_code++){
668             for(mv=-MAX_MV; mv<=MAX_MV; mv++){
669                 int len;
670
671                 if(mv==0) len= mbMotionVectorTable[0][1];
672                 else{
673                     int val, bit_size, range, code;
674
675                     bit_size = s->f_code - 1;
676                     range = 1 << bit_size;
677
678                     val=mv;
679                     if (val < 0) 
680                         val = -val;
681                     val--;
682                     code = (val >> bit_size) + 1;
683                     if(code<17){
684                         len= mbMotionVectorTable[code][1] + 1 + bit_size;
685                     }else{
686                         len= mbMotionVectorTable[16][1] + 2 + bit_size;
687                     }
688                 }
689
690                 mv_penalty[f_code][mv+MAX_MV]= len;
691             }
692         }
693         
694
695         for(f_code=MAX_FCODE; f_code>0; f_code--){
696             for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
697                 fcode_tab[mv+MAX_MV]= f_code;
698             }
699         }
700     }
701     s->me.mv_penalty= mv_penalty;
702     s->fcode_tab= fcode_tab;
703     s->min_qcoeff=-255;
704     s->max_qcoeff= 255;
705     s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
706     s->inter_quant_bias= 0;
707     s->intra_ac_vlc_length=
708     s->inter_ac_vlc_length= uni_mpeg1_ac_vlc_len;
709 }
710
711 static inline void encode_dc(MpegEncContext *s, int diff, int component)
712 {
713     if (component == 0) {
714         put_bits(
715             &s->pb, 
716             mpeg1_lum_dc_uni[diff+255]&0xFF,
717             mpeg1_lum_dc_uni[diff+255]>>8);
718     } else {
719         put_bits(
720             &s->pb, 
721             mpeg1_chr_dc_uni[diff+255]&0xFF,
722             mpeg1_chr_dc_uni[diff+255]>>8);
723     }
724 }
725
726 static void mpeg1_encode_block(MpegEncContext *s, 
727                                DCTELEM *block, 
728                                int n)
729 {
730     int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
731     int code, component;
732 //    RLTable *rl = &rl_mpeg1;
733
734     last_index = s->block_last_index[n];
735
736     /* DC coef */
737     if (s->mb_intra) {
738         component = (n <= 3 ? 0 : n - 4 + 1);
739         dc = block[0]; /* overflow is impossible */
740         diff = dc - s->last_dc[component];
741         encode_dc(s, diff, component);
742         s->last_dc[component] = dc;
743         i = 1;
744     } else {
745         /* encode the first coefficient : needs to be done here because
746            it is handled slightly differently */
747         level = block[0];
748         if (abs(level) == 1) {
749                 code = ((uint32_t)level >> 31); /* the sign bit */
750                 put_bits(&s->pb, 2, code | 0x02);
751                 i = 1;
752         } else {
753             i = 0;
754             last_non_zero = -1;
755             goto next_coef;
756         }
757     }
758
759     /* now quantify & encode AC coefs */
760     last_non_zero = i - 1;
761
762     for(;i<=last_index;i++) {
763         j = s->intra_scantable.permutated[i];
764         level = block[j];
765     next_coef:
766 #if 0
767         if (level != 0)
768             dprintf("level[%d]=%d\n", i, level);
769 #endif            
770         /* encode using VLC */
771         if (level != 0) {
772             run = i - last_non_zero - 1;
773             
774             alevel= level;
775             MASK_ABS(sign, alevel)
776             sign&=1;
777
778 //            code = get_rl_index(rl, 0, run, alevel);
779             if (alevel <= mpeg1_max_level[0][run]){
780                 code= mpeg1_index_run[0][run] + alevel - 1;
781                 /* store the vlc & sign at once */
782                 put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
783             } else {
784                 /* escape seems to be pretty rare <5% so i dont optimize it */
785                 put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
786                 /* escape: only clip in this case */
787                 put_bits(&s->pb, 6, run);
788                 if (alevel < 128) {
789                     put_bits(&s->pb, 8, level & 0xff);
790                 } else {
791                     if (level < 0) {
792                         put_bits(&s->pb, 16, 0x8001 + level + 255);
793                     } else {
794                         put_bits(&s->pb, 16, level & 0xffff);
795                     }
796                 }
797             }
798             last_non_zero = i;
799         }
800     }
801     /* end of block */
802     put_bits(&s->pb, 2, 0x2);
803 }
804 #endif //CONFIG_ENCODERS
805
806 /******************************************/
807 /* decoding */
808
809 static VLC dc_lum_vlc;
810 static VLC dc_chroma_vlc;
811 static VLC mv_vlc;
812 static VLC mbincr_vlc;
813 static VLC mb_ptype_vlc;
814 static VLC mb_btype_vlc;
815 static VLC mb_pat_vlc;
816
817 static void init_vlcs(MpegEncContext *s)
818 {
819     static int done = 0;
820
821     if (!done) {
822         done = 1;
823
824         init_vlc(&dc_lum_vlc, DC_VLC_BITS, 12, 
825                  vlc_dc_lum_bits, 1, 1,
826                  vlc_dc_lum_code, 2, 2);
827         init_vlc(&dc_chroma_vlc,  DC_VLC_BITS, 12, 
828                  vlc_dc_chroma_bits, 1, 1,
829                  vlc_dc_chroma_code, 2, 2);
830         init_vlc(&mv_vlc, MV_VLC_BITS, 17, 
831                  &mbMotionVectorTable[0][1], 2, 1,
832                  &mbMotionVectorTable[0][0], 2, 1);
833         init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 35, 
834                  &mbAddrIncrTable[0][1], 2, 1,
835                  &mbAddrIncrTable[0][0], 2, 1);
836         init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 63, 
837                  &mbPatTable[0][1], 2, 1,
838                  &mbPatTable[0][0], 2, 1);
839         
840         init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 32, 
841                  &table_mb_ptype[0][1], 2, 1,
842                  &table_mb_ptype[0][0], 2, 1);
843         init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 32, 
844                  &table_mb_btype[0][1], 2, 1,
845                  &table_mb_btype[0][0], 2, 1);
846         init_rl(&rl_mpeg1);
847         init_rl(&rl_mpeg2);
848
849         init_2d_vlc_rl(&rl_mpeg1);
850         init_2d_vlc_rl(&rl_mpeg2);
851     }
852 }
853
854 static inline int get_dmv(MpegEncContext *s)
855 {
856     if(get_bits1(&s->gb)) 
857         return 1 - (get_bits1(&s->gb) << 1);
858     else
859         return 0;
860 }
861
862 static inline int get_qscale(MpegEncContext *s)
863 {
864     int qscale;
865     if (s->mpeg2) {
866         if (s->q_scale_type) {
867             qscale = non_linear_qscale[get_bits(&s->gb, 5)];
868         } else {
869             qscale = get_bits(&s->gb, 5) << 1;
870         }
871     } else {
872         /* for mpeg1, we use the generic unquant code */
873         qscale = get_bits(&s->gb, 5);
874     }
875     return qscale;
876 }
877
878 /* motion type (for mpeg2) */
879 #define MT_FIELD 1
880 #define MT_FRAME 2
881 #define MT_16X8  2
882 #define MT_DMV   3
883
884 static int mpeg_decode_mb(MpegEncContext *s,
885                           DCTELEM block[6][64])
886 {
887     int i, j, k, cbp, val, mb_type, motion_type;
888     
889     dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
890
891     assert(s->mb_skiped==0);
892
893     if (--s->mb_incr != 0) {
894         /* skip mb */
895         s->mb_intra = 0;
896         for(i=0;i<6;i++)
897             s->block_last_index[i] = -1;
898         s->mv_type = MV_TYPE_16X16;
899         if (s->pict_type == P_TYPE) {
900             /* if P type, zero motion vector is implied */
901             s->mv_dir = MV_DIR_FORWARD;
902             s->mv[0][0][0] = s->mv[0][0][1] = 0;
903             s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
904             s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
905             s->mb_skiped = 1;
906         } else {
907             /* if B type, reuse previous vectors and directions */
908             s->mv[0][0][0] = s->last_mv[0][0][0];
909             s->mv[0][0][1] = s->last_mv[0][0][1];
910             s->mv[1][0][0] = s->last_mv[1][0][0];
911             s->mv[1][0][1] = s->last_mv[1][0][1];
912
913             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0) 
914                 s->mb_skiped = 1;
915         }
916
917         return 0;
918     }
919
920     switch(s->pict_type) {
921     default:
922     case I_TYPE:
923         if (get_bits1(&s->gb) == 0) {
924             if (get_bits1(&s->gb) == 0)
925                 return -1;
926             mb_type = MB_QUANT | MB_INTRA;
927         } else {
928             mb_type = MB_INTRA;
929         }
930         break;
931     case P_TYPE:
932         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
933         if (mb_type < 0){
934             fprintf(stderr, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
935             return -1;
936         }
937         break;
938     case B_TYPE:
939         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
940         if (mb_type < 0){
941             fprintf(stderr, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
942             return -1;
943         }
944         break;
945     }
946     dprintf("mb_type=%x\n", mb_type);
947     motion_type = 0; /* avoid warning */
948     if (mb_type & (MB_FOR|MB_BACK)) {
949         /* get additionnal motion vector type */
950         if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) 
951             motion_type = MT_FRAME;
952         else
953             motion_type = get_bits(&s->gb, 2);
954     }
955     /* compute dct type */
956     if (s->picture_structure == PICT_FRAME && 
957         !s->frame_pred_frame_dct &&
958         (mb_type & (MB_PAT | MB_INTRA))) {
959         s->interlaced_dct = get_bits1(&s->gb);
960 #ifdef DEBUG
961         if (s->interlaced_dct)
962             printf("interlaced_dct\n");
963 #endif
964     } else {
965         s->interlaced_dct = 0; /* frame based */
966     }
967
968     if (mb_type & MB_QUANT) {
969         s->qscale = get_qscale(s);
970     }
971     if (mb_type & MB_INTRA) {
972         if (s->concealment_motion_vectors) {
973             /* just parse them */
974             if (s->picture_structure != PICT_FRAME) 
975                 skip_bits1(&s->gb); /* field select */
976             mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
977             mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
978         }
979         s->mb_intra = 1;
980         cbp = 0x3f;
981         memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
982     } else {
983         s->mb_intra = 0;
984         cbp = 0;
985     }
986     /* special case of implicit zero motion vector */
987     if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
988         s->mv_dir = MV_DIR_FORWARD;
989         s->mv_type = MV_TYPE_16X16;
990         s->last_mv[0][0][0] = 0;
991         s->last_mv[0][0][1] = 0;
992         s->last_mv[0][1][0] = 0;
993         s->last_mv[0][1][1] = 0;
994         s->mv[0][0][0] = 0;
995         s->mv[0][0][1] = 0;
996     } else if (mb_type & (MB_FOR | MB_BACK)) {
997         /* motion vectors */
998         s->mv_dir = 0;
999         for(i=0;i<2;i++) {
1000             if (mb_type & (MB_FOR >> i)) {
1001                 s->mv_dir |= (MV_DIR_FORWARD >> i);
1002                 dprintf("motion_type=%d\n", motion_type);
1003                 switch(motion_type) {
1004                 case MT_FRAME: /* or MT_16X8 */
1005                     if (s->picture_structure == PICT_FRAME) {
1006                         /* MT_FRAME */
1007                         s->mv_type = MV_TYPE_16X16;
1008                         for(k=0;k<2;k++) {
1009                             val = mpeg_decode_motion(s, s->mpeg_f_code[i][k], 
1010                                                      s->last_mv[i][0][k]);
1011                             s->last_mv[i][0][k] = val;
1012                             s->last_mv[i][1][k] = val;
1013                             /* full_pel: only for mpeg1 */
1014                             if (s->full_pel[i])
1015                                 val = val << 1;
1016                             s->mv[i][0][k] = val;
1017                             dprintf("mv%d: %d\n", k, val);
1018                         }
1019                     } else {
1020                         /* MT_16X8 */
1021                         s->mv_type = MV_TYPE_16X8;
1022                         for(j=0;j<2;j++) {
1023                             s->field_select[i][j] = get_bits1(&s->gb);
1024                             for(k=0;k<2;k++) {
1025                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
1026                                                          s->last_mv[i][j][k]);
1027                                 s->last_mv[i][j][k] = val;
1028                                 s->mv[i][j][k] = val;
1029                             }
1030                         }
1031                     }
1032                     break;
1033                 case MT_FIELD:
1034                     s->mv_type = MV_TYPE_FIELD;
1035                     if (s->picture_structure == PICT_FRAME) {
1036                         for(j=0;j<2;j++) {
1037                             s->field_select[i][j] = get_bits1(&s->gb);
1038                             val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
1039                                                      s->last_mv[i][j][0]);
1040                             s->last_mv[i][j][0] = val;
1041                             s->mv[i][j][0] = val;
1042                             dprintf("fmx=%d\n", val);
1043                             val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
1044                                                      s->last_mv[i][j][1] >> 1);
1045                             s->last_mv[i][j][1] = val << 1;
1046                             s->mv[i][j][1] = val;
1047                             dprintf("fmy=%d\n", val);
1048                         }
1049                     } else {
1050                         s->field_select[i][0] = get_bits1(&s->gb);
1051                         for(k=0;k<2;k++) {
1052                             val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
1053                                                      s->last_mv[i][0][k]);
1054                             s->last_mv[i][0][k] = val;
1055                             s->last_mv[i][1][k] = val;
1056                             s->mv[i][0][k] = val;
1057                         }
1058                     }
1059                     break;
1060                 case MT_DMV:
1061                     {
1062                         int dmx, dmy, mx, my, m;
1063
1064                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0], 
1065                                                 s->last_mv[i][0][0]);
1066                         s->last_mv[i][0][0] = mx;
1067                         s->last_mv[i][1][0] = mx;
1068                         dmx = get_dmv(s);
1069                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1], 
1070                                                 s->last_mv[i][0][1] >> 1);
1071                         dmy = get_dmv(s);
1072                         s->mv_type = MV_TYPE_DMV;
1073                         /* XXX: totally broken */
1074                         if (s->picture_structure == PICT_FRAME) {
1075                             s->last_mv[i][0][1] = my << 1;
1076                             s->last_mv[i][1][1] = my << 1;
1077
1078                             m = s->top_field_first ? 1 : 3;
1079                             /* top -> top pred */
1080                             s->mv[i][0][0] = mx; 
1081                             s->mv[i][0][1] = my << 1;
1082                             s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1083                             s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
1084                             m = 4 - m;
1085                             s->mv[i][2][0] = mx;
1086                             s->mv[i][2][1] = my << 1;
1087                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1088                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
1089                         } else {
1090                             s->last_mv[i][0][1] = my;
1091                             s->last_mv[i][1][1] = my;
1092                             s->mv[i][0][0] = mx;
1093                             s->mv[i][0][1] = my;
1094                             s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
1095                             s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1 
1096                                 /* + 2 * cur_field */;
1097                         }
1098                     }
1099                     break;
1100                 }
1101             }
1102         }
1103     }
1104
1105     if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
1106         skip_bits1(&s->gb); /* marker */
1107     }
1108     
1109     if (mb_type & MB_PAT) {
1110         cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
1111         if (cbp < 0){
1112             fprintf(stderr, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
1113             return -1;
1114         }
1115         cbp++;
1116     }
1117     dprintf("cbp=%x\n", cbp);
1118
1119     if (s->mpeg2) {
1120         if (s->mb_intra) {
1121             for(i=0;i<6;i++) {
1122                 if (mpeg2_decode_block_intra(s, block[i], i) < 0)
1123                     return -1;
1124             }
1125         } else {
1126             for(i=0;i<6;i++) {
1127                 if (cbp & 32) {
1128                     if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
1129                         return -1;
1130                 } else {
1131                     s->block_last_index[i] = -1;
1132                 }
1133                 cbp+=cbp;
1134             }
1135         }
1136     } else {
1137         if (s->mb_intra) {
1138             for(i=0;i<6;i++) {
1139                 if (mpeg1_decode_block_intra(s, block[i], i) < 0)
1140                     return -1;
1141             }
1142         }else{
1143             for(i=0;i<6;i++) {
1144                 if (cbp & 32) {
1145                     if (mpeg1_decode_block_inter(s, block[i], i) < 0)
1146                         return -1;
1147                 } else {
1148                     s->block_last_index[i] = -1;
1149                 }
1150                 cbp+=cbp;
1151             }
1152         }
1153     }
1154     return 0;
1155 }
1156
1157 /* as h263, but only 17 codes */
1158 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
1159 {
1160     int code, sign, val, m, l, shift;
1161
1162     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
1163     if (code < 0) {
1164         return 0xffff;
1165     }
1166     if (code == 0) {
1167         return pred;
1168     }
1169     sign = get_bits1(&s->gb);
1170     shift = fcode - 1;
1171     val = (code - 1) << shift;
1172     if (shift > 0)
1173         val |= get_bits(&s->gb, shift);
1174     val++;
1175     if (sign)
1176         val = -val;
1177     val += pred;
1178     
1179     /* modulo decoding */
1180     l = (1 << shift) * 16;
1181     m = 2 * l;
1182     if (val < -l) {
1183         val += m;
1184     } else if (val >= l) {
1185         val -= m;
1186     }
1187     return val;
1188 }
1189
1190 static inline int decode_dc(MpegEncContext *s, int component)
1191 {
1192     int code, diff;
1193
1194     if (component == 0) {
1195         code = get_vlc2(&s->gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
1196     } else {
1197         code = get_vlc2(&s->gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
1198     }
1199     if (code < 0){
1200         fprintf(stderr, "invalid dc code at %d %d\n", s->mb_x, s->mb_y);
1201         return 0xffff;
1202     }
1203     if (code == 0) {
1204         diff = 0;
1205     } else {
1206         diff = get_bits(&s->gb, code);
1207         if ((diff & (1 << (code - 1))) == 0) 
1208             diff = (-1 << code) | (diff + 1);
1209     }
1210     return diff;
1211 }
1212
1213 static inline int mpeg1_decode_block_intra(MpegEncContext *s, 
1214                                DCTELEM *block, 
1215                                int n)
1216 {
1217     int level, dc, diff, i, j, run;
1218     int component;
1219     RLTable *rl = &rl_mpeg1;
1220     uint8_t * const scantable= s->intra_scantable.permutated;
1221     const uint16_t *quant_matrix= s->intra_matrix;
1222     const int qscale= s->qscale;
1223
1224     /* DC coef */
1225     component = (n <= 3 ? 0 : n - 4 + 1);
1226     diff = decode_dc(s, component);
1227     if (diff >= 0xffff)
1228         return -1;
1229     dc = s->last_dc[component];
1230     dc += diff;
1231     s->last_dc[component] = dc;
1232     block[0] = dc<<3;
1233     dprintf("dc=%d diff=%d\n", dc, diff);
1234     i = 0;
1235     {
1236         OPEN_READER(re, &s->gb);    
1237         /* now quantify & encode AC coefs */
1238         for(;;) {
1239             UPDATE_CACHE(re, &s->gb);
1240             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1241             
1242             if(level == 127){
1243                 break;
1244             } else if(level != 0) {
1245                 i += run;
1246                 j = scantable[i];
1247                 level= (level*qscale*quant_matrix[j])>>3;
1248                 level= (level-1)|1;
1249                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1250                 LAST_SKIP_BITS(re, &s->gb, 1);
1251             } else {
1252                 /* escape */
1253                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1254                 UPDATE_CACHE(re, &s->gb);
1255                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
1256                 if (level == -128) {
1257                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
1258                 } else if (level == 0) {
1259                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
1260                 }
1261                 i += run;
1262                 j = scantable[i];
1263                 if(level<0){
1264                     level= -level;
1265                     level= (level*qscale*quant_matrix[j])>>3;
1266                     level= (level-1)|1;
1267                     level= -level;
1268                 }else{
1269                     level= (level*qscale*quant_matrix[j])>>3;
1270                     level= (level-1)|1;
1271                 }
1272             }
1273             if (i > 63){
1274                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1275                 return -1;
1276             }
1277
1278             block[j] = level;
1279         }
1280         CLOSE_READER(re, &s->gb);
1281     }
1282     s->block_last_index[n] = i;
1283    return 0;
1284 }
1285
1286 static inline int mpeg1_decode_block_inter(MpegEncContext *s, 
1287                                DCTELEM *block, 
1288                                int n)
1289 {
1290     int level, i, j, run;
1291     RLTable *rl = &rl_mpeg1;
1292     uint8_t * const scantable= s->intra_scantable.permutated;
1293     const uint16_t *quant_matrix= s->inter_matrix;
1294     const int qscale= s->qscale;
1295
1296     {
1297         int v;
1298         OPEN_READER(re, &s->gb);
1299         i = -1;
1300         /* special case for the first coef. no need to add a second vlc table */
1301         UPDATE_CACHE(re, &s->gb);
1302         v= SHOW_UBITS(re, &s->gb, 2);
1303         if (v & 2) {
1304             LAST_SKIP_BITS(re, &s->gb, 2);
1305             level= (3*qscale*quant_matrix[0])>>4;
1306             level= (level-1)|1;
1307             if(v&1)
1308                 level= -level;
1309             block[0] = level;
1310             i++;
1311         }
1312
1313         /* now quantify & encode AC coefs */
1314         for(;;) {
1315             UPDATE_CACHE(re, &s->gb);
1316             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1317             
1318             if(level == 127){
1319                 break;
1320             } else if(level != 0) {
1321                 i += run;
1322                 j = scantable[i];
1323                 level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1324                 level= (level-1)|1;
1325                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1326                 LAST_SKIP_BITS(re, &s->gb, 1);
1327             } else {
1328                 /* escape */
1329                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1330                 UPDATE_CACHE(re, &s->gb);
1331                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
1332                 if (level == -128) {
1333                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
1334                 } else if (level == 0) {
1335                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
1336                 }
1337                 i += run;
1338                 j = scantable[i];
1339                 if(level<0){
1340                     level= -level;
1341                     level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1342                     level= (level-1)|1;
1343                     level= -level;
1344                 }else{
1345                     level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1346                     level= (level-1)|1;
1347                 }
1348             }
1349             if (i > 63){
1350                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1351                 return -1;
1352             }
1353
1354             block[j] = level;
1355         }
1356         CLOSE_READER(re, &s->gb);
1357     }
1358     s->block_last_index[n] = i;
1359     return 0;
1360 }
1361
1362 /* Also does unquantization here, since I will never support mpeg2
1363    encoding */
1364 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s, 
1365                                DCTELEM *block, 
1366                                int n)
1367 {
1368     int level, i, j, run;
1369     RLTable *rl = &rl_mpeg1;
1370     uint8_t * const scantable= s->intra_scantable.permutated;
1371     const uint16_t *quant_matrix;
1372     const int qscale= s->qscale;
1373     int mismatch;
1374
1375     mismatch = 1;
1376
1377     {
1378         int v;
1379         OPEN_READER(re, &s->gb);
1380         i = -1;
1381         if (n < 4)
1382             quant_matrix = s->inter_matrix;
1383         else
1384             quant_matrix = s->chroma_inter_matrix;
1385
1386         /* special case for the first coef. no need to add a second vlc table */
1387         UPDATE_CACHE(re, &s->gb);
1388         v= SHOW_UBITS(re, &s->gb, 2);
1389         if (v & 2) {
1390             LAST_SKIP_BITS(re, &s->gb, 2);
1391             level= (3*qscale*quant_matrix[0])>>5;
1392             if(v&1)
1393                 level= -level;
1394             block[0] = level;
1395             mismatch ^= level;
1396             i++;
1397         }
1398
1399         /* now quantify & encode AC coefs */
1400         for(;;) {
1401             UPDATE_CACHE(re, &s->gb);
1402             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1403             
1404             if(level == 127){
1405                 break;
1406             } else if(level != 0) {
1407                 i += run;
1408                 j = scantable[i];
1409                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
1410                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1411                 LAST_SKIP_BITS(re, &s->gb, 1);
1412             } else {
1413                 /* escape */
1414                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1415                 UPDATE_CACHE(re, &s->gb);
1416                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1417
1418                 i += run;
1419                 j = scantable[i];
1420                 if(level<0){
1421                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
1422                     level= -level;
1423                 }else{
1424                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
1425                 }
1426             }
1427             if (i > 63){
1428                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1429                 return -1;
1430             }
1431             
1432             mismatch ^= level;
1433             block[j] = level;
1434         }
1435         CLOSE_READER(re, &s->gb);
1436     }
1437     block[63] ^= (mismatch & 1);
1438     
1439     s->block_last_index[n] = i;
1440     return 0;
1441 }
1442
1443 static inline int mpeg2_decode_block_intra(MpegEncContext *s, 
1444                                DCTELEM *block, 
1445                                int n)
1446 {
1447     int level, dc, diff, i, j, run;
1448     int component;
1449     RLTable *rl;
1450     uint8_t * const scantable= s->intra_scantable.permutated;
1451     const uint16_t *quant_matrix;
1452     const int qscale= s->qscale;
1453     int mismatch;
1454
1455     /* DC coef */
1456     if (n < 4){
1457         quant_matrix = s->intra_matrix;
1458         component = 0; 
1459     }else{
1460         quant_matrix = s->chroma_intra_matrix;
1461         component = n - 3;
1462     }
1463     diff = decode_dc(s, component);
1464     if (diff >= 0xffff)
1465         return -1;
1466     dc = s->last_dc[component];
1467     dc += diff;
1468     s->last_dc[component] = dc;
1469     block[0] = dc << (3 - s->intra_dc_precision);
1470     dprintf("dc=%d\n", block[0]);
1471     mismatch = block[0] ^ 1;
1472     i = 0;
1473     if (s->intra_vlc_format)
1474         rl = &rl_mpeg2;
1475     else
1476         rl = &rl_mpeg1;
1477
1478     {
1479         OPEN_READER(re, &s->gb);    
1480         /* now quantify & encode AC coefs */
1481         for(;;) {
1482             UPDATE_CACHE(re, &s->gb);
1483             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1484             
1485             if(level == 127){
1486                 break;
1487             } else if(level != 0) {
1488                 i += run;
1489                 j = scantable[i];
1490                 level= (level*qscale*quant_matrix[j])>>4;
1491                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1492                 LAST_SKIP_BITS(re, &s->gb, 1);
1493             } else {
1494                 /* escape */
1495                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1496                 UPDATE_CACHE(re, &s->gb);
1497                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1498                 i += run;
1499                 j = scantable[i];
1500                 if(level<0){
1501                     level= (-level*qscale*quant_matrix[j])>>4;
1502                     level= -level;
1503                 }else{
1504                     level= (level*qscale*quant_matrix[j])>>4;
1505                 }
1506             }
1507             if (i > 63){
1508                 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1509                 return -1;
1510             }
1511             
1512             mismatch^= level;
1513             block[j] = level;
1514         }
1515         CLOSE_READER(re, &s->gb);
1516     }
1517     block[63]^= mismatch&1;
1518     
1519     s->block_last_index[n] = i;
1520     return 0;
1521 }
1522
1523 /* compressed picture size */
1524 #define PICTURE_BUFFER_SIZE 100000
1525
1526 typedef struct Mpeg1Context {
1527     MpegEncContext mpeg_enc_ctx;
1528     uint32_t header_state;
1529     int start_code; /* current start code */
1530     uint8_t buffer[PICTURE_BUFFER_SIZE]; 
1531     uint8_t *buf_ptr;
1532     int buffer_size;
1533     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1534     int repeat_field; /* true if we must repeat the field */
1535 } Mpeg1Context;
1536
1537 static int mpeg_decode_init(AVCodecContext *avctx)
1538 {
1539     Mpeg1Context *s = avctx->priv_data;
1540     
1541     s->mpeg_enc_ctx.flags= avctx->flags;
1542     common_init(&s->mpeg_enc_ctx);
1543     init_vlcs(&s->mpeg_enc_ctx);
1544
1545     s->header_state = 0xff;
1546     s->mpeg_enc_ctx_allocated = 0;
1547     s->buffer_size = PICTURE_BUFFER_SIZE;
1548     s->start_code = -1;
1549     s->buf_ptr = s->buffer;
1550     s->mpeg_enc_ctx.picture_number = 0;
1551     s->repeat_field = 0;
1552     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1553     return 0;
1554 }
1555
1556 /* return the 8 bit start code value and update the search
1557    state. Return -1 if no start code found */
1558 static int find_start_code(uint8_t **pbuf_ptr, uint8_t *buf_end, 
1559                            uint32_t *header_state)
1560 {
1561     uint8_t *buf_ptr;
1562     unsigned int state, v;
1563     int val;
1564
1565     state = *header_state;
1566     buf_ptr = *pbuf_ptr;
1567     while (buf_ptr < buf_end) {
1568         v = *buf_ptr++;
1569         if (state == 0x000001) {
1570             state = ((state << 8) | v) & 0xffffff;
1571             val = state;
1572             goto found;
1573         }
1574         state = ((state << 8) | v) & 0xffffff;
1575     }
1576     val = -1;
1577  found:
1578     *pbuf_ptr = buf_ptr;
1579     *header_state = state;
1580     return val;
1581 }
1582
1583 static int mpeg1_decode_picture(AVCodecContext *avctx, 
1584                                 uint8_t *buf, int buf_size)
1585 {
1586     Mpeg1Context *s1 = avctx->priv_data;
1587     MpegEncContext *s = &s1->mpeg_enc_ctx;
1588     int ref, f_code;
1589
1590     init_get_bits(&s->gb, buf, buf_size*8);
1591
1592     ref = get_bits(&s->gb, 10); /* temporal ref */
1593     s->pict_type = get_bits(&s->gb, 3);
1594     dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1595
1596     skip_bits(&s->gb, 16);
1597     if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1598         s->full_pel[0] = get_bits1(&s->gb);
1599         f_code = get_bits(&s->gb, 3);
1600         if (f_code == 0)
1601             return -1;
1602         s->mpeg_f_code[0][0] = f_code;
1603         s->mpeg_f_code[0][1] = f_code;
1604     }
1605     if (s->pict_type == B_TYPE) {
1606         s->full_pel[1] = get_bits1(&s->gb);
1607         f_code = get_bits(&s->gb, 3);
1608         if (f_code == 0)
1609             return -1;
1610         s->mpeg_f_code[1][0] = f_code;
1611         s->mpeg_f_code[1][1] = f_code;
1612     }
1613     s->current_picture.pict_type= s->pict_type;
1614     s->current_picture.key_frame= s->pict_type == I_TYPE;
1615     
1616     s->y_dc_scale = 8;
1617     s->c_dc_scale = 8;
1618     s->first_slice = 1;
1619     return 0;
1620 }
1621
1622 static void mpeg_decode_sequence_extension(MpegEncContext *s)
1623 {
1624     int horiz_size_ext, vert_size_ext;
1625     int bit_rate_ext, vbv_buf_ext;
1626     int frame_rate_ext_n, frame_rate_ext_d;
1627     float aspect;
1628
1629     skip_bits(&s->gb, 8); /* profil and level */
1630     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1631     skip_bits(&s->gb, 2); /* chroma_format */
1632     horiz_size_ext = get_bits(&s->gb, 2);
1633     vert_size_ext = get_bits(&s->gb, 2);
1634     s->width |= (horiz_size_ext << 12);
1635     s->height |= (vert_size_ext << 12);
1636     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1637     s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1638     skip_bits1(&s->gb); /* marker */
1639     vbv_buf_ext = get_bits(&s->gb, 8);
1640     s->low_delay = get_bits1(&s->gb);
1641     frame_rate_ext_n = get_bits(&s->gb, 2);
1642     frame_rate_ext_d = get_bits(&s->gb, 5);
1643     av_reduce(
1644         &s->avctx->frame_rate, 
1645         &s->avctx->frame_rate_base, 
1646         frame_rate_tab[s->frame_rate_index] * (frame_rate_ext_n+1),
1647         MPEG1_FRAME_RATE_BASE * (frame_rate_ext_d+1),
1648         1<<30);
1649
1650     dprintf("sequence extension\n");
1651     s->mpeg2 = 1;
1652     s->avctx->sub_id = 2; /* indicates mpeg2 found */
1653
1654     aspect= mpeg2_aspect[s->aspect_ratio_info];
1655     if(aspect>0.0)      s->avctx->aspect_ratio= s->width/(aspect*s->height);
1656     else if(aspect<0.0) s->avctx->aspect_ratio= -1.0/aspect;
1657 }
1658
1659 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1660 {
1661     int i, v, j;
1662
1663     dprintf("matrix extension\n");
1664
1665     if (get_bits1(&s->gb)) {
1666         for(i=0;i<64;i++) {
1667             v = get_bits(&s->gb, 8);
1668             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1669             s->intra_matrix[j] = v;
1670             s->chroma_intra_matrix[j] = v;
1671         }
1672     }
1673     if (get_bits1(&s->gb)) {
1674         for(i=0;i<64;i++) {
1675             v = get_bits(&s->gb, 8);
1676             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1677             s->inter_matrix[j] = v;
1678             s->chroma_inter_matrix[j] = v;
1679         }
1680     }
1681     if (get_bits1(&s->gb)) {
1682         for(i=0;i<64;i++) {
1683             v = get_bits(&s->gb, 8);
1684             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1685             s->chroma_intra_matrix[j] = v;
1686         }
1687     }
1688     if (get_bits1(&s->gb)) {
1689         for(i=0;i<64;i++) {
1690             v = get_bits(&s->gb, 8);
1691             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1692             s->chroma_inter_matrix[j] = v;
1693         }
1694     }
1695 }
1696
1697 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1698 {
1699     s->full_pel[0] = s->full_pel[1] = 0;
1700     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1701     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1702     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1703     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1704     s->intra_dc_precision = get_bits(&s->gb, 2);
1705     s->picture_structure = get_bits(&s->gb, 2);
1706     s->top_field_first = get_bits1(&s->gb);
1707     s->frame_pred_frame_dct = get_bits1(&s->gb);
1708     s->concealment_motion_vectors = get_bits1(&s->gb);
1709     s->q_scale_type = get_bits1(&s->gb);
1710     s->intra_vlc_format = get_bits1(&s->gb);
1711     s->alternate_scan = get_bits1(&s->gb);
1712     s->repeat_first_field = get_bits1(&s->gb);
1713     s->chroma_420_type = get_bits1(&s->gb);
1714     s->progressive_frame = get_bits1(&s->gb);
1715     
1716     if(s->picture_structure == PICT_FRAME)
1717         s->first_field=0;
1718     else{
1719         s->first_field ^= 1;
1720         memset(s->mbskip_table, 0, s->mb_width*s->mb_height);
1721     }
1722     
1723     if(s->alternate_scan){
1724         ff_init_scantable(s, &s->inter_scantable  , ff_alternate_vertical_scan);
1725         ff_init_scantable(s, &s->intra_scantable  , ff_alternate_vertical_scan);
1726         ff_init_scantable(s, &s->intra_h_scantable, ff_alternate_vertical_scan);
1727         ff_init_scantable(s, &s->intra_v_scantable, ff_alternate_vertical_scan);
1728     }else{
1729         ff_init_scantable(s, &s->inter_scantable  , ff_zigzag_direct);
1730         ff_init_scantable(s, &s->intra_scantable  , ff_zigzag_direct);
1731         ff_init_scantable(s, &s->intra_h_scantable, ff_alternate_horizontal_scan);
1732         ff_init_scantable(s, &s->intra_v_scantable, ff_alternate_vertical_scan);
1733     }
1734     
1735     /* composite display not parsed */
1736     dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1737     dprintf("picture_structure=%d\n", s->picture_structure);
1738     dprintf("top field first=%d\n", s->top_field_first);
1739     dprintf("repeat first field=%d\n", s->repeat_first_field);
1740     dprintf("conceal=%d\n", s->concealment_motion_vectors);
1741     dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1742     dprintf("alternate_scan=%d\n", s->alternate_scan);
1743     dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1744     dprintf("progressive_frame=%d\n", s->progressive_frame);
1745 }
1746
1747 static void mpeg_decode_extension(AVCodecContext *avctx, 
1748                                   uint8_t *buf, int buf_size)
1749 {
1750     Mpeg1Context *s1 = avctx->priv_data;
1751     MpegEncContext *s = &s1->mpeg_enc_ctx;
1752     int ext_type;
1753
1754     init_get_bits(&s->gb, buf, buf_size*8);
1755     
1756     ext_type = get_bits(&s->gb, 4);
1757     switch(ext_type) {
1758     case 0x1:
1759         /* sequence ext */
1760         mpeg_decode_sequence_extension(s);
1761         break;
1762     case 0x3:
1763         /* quant matrix extension */
1764         mpeg_decode_quant_matrix_extension(s);
1765         break;
1766     case 0x8:
1767         /* picture extension */
1768         mpeg_decode_picture_coding_extension(s);
1769         break;
1770     }
1771 }
1772
1773 #define DECODE_SLICE_FATAL_ERROR -2
1774 #define DECODE_SLICE_ERROR -1
1775 #define DECODE_SLICE_OK 0
1776 #define DECODE_SLICE_EOP 1
1777
1778 /**
1779  * decodes a slice.
1780  * @return DECODE_SLICE_FATAL_ERROR if a non recoverable error occured<br>
1781  *         DECODE_SLICE_ERROR if the slice is damaged<br>
1782  *         DECODE_SLICE_OK if this slice is ok<br>
1783  *         DECODE_SLICE_EOP if the end of the picture is reached
1784  */
1785 static int mpeg_decode_slice(AVCodecContext *avctx, 
1786                               AVFrame *pict,
1787                               int start_code,
1788                               uint8_t *buf, int buf_size)
1789 {
1790     Mpeg1Context *s1 = avctx->priv_data;
1791     MpegEncContext *s = &s1->mpeg_enc_ctx;
1792     int ret;
1793     const int field_pic= s->picture_structure != PICT_FRAME;
1794
1795     start_code = (start_code - 1) & 0xff;
1796     if (start_code >= s->mb_height){
1797         fprintf(stderr, "slice below image (%d >= %d)\n", start_code, s->mb_height);
1798         return DECODE_SLICE_ERROR;
1799     }
1800     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1801     s->last_dc[1] = s->last_dc[0];
1802     s->last_dc[2] = s->last_dc[0];
1803     memset(s->last_mv, 0, sizeof(s->last_mv));
1804         
1805     /* start frame decoding */
1806     if (s->first_slice) {
1807       if(s->first_field || s->picture_structure==PICT_FRAME){
1808         if(MPV_frame_start(s, avctx) < 0)
1809             return DECODE_SLICE_FATAL_ERROR;
1810         /* first check if we must repeat the frame */
1811         s->current_picture.repeat_pict = 0;
1812
1813         if (s->repeat_first_field) {
1814             if (s->progressive_sequence) {
1815                 if (s->top_field_first)
1816                     s->current_picture.repeat_pict = 4;
1817                 else
1818                     s->current_picture.repeat_pict = 2;
1819             } else if (s->progressive_frame) {
1820                 s->current_picture.repeat_pict = 1;
1821             }
1822         }         
1823 //        printf("%d \n", s->current_picture.repeat_pict);
1824
1825         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1826              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", 
1827                  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],
1828                  s->pict_type == I_TYPE ? "I" : (s->pict_type == P_TYPE ? "P" : (s->pict_type == B_TYPE ? "B" : "S")), 
1829                  s->progressive_sequence ? "pro" :"", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"", 
1830                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1831                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1832         }
1833       }else{ //second field
1834             int i;
1835             for(i=0; i<4; i++){
1836                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1837                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1838                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1839                 } 
1840             }
1841       }
1842     }
1843     s->first_slice = 0;
1844
1845     init_get_bits(&s->gb, buf, buf_size*8);
1846
1847     s->qscale = get_qscale(s);
1848     /* extra slice info */
1849     while (get_bits1(&s->gb) != 0) {
1850         skip_bits(&s->gb, 8);
1851     }
1852
1853     s->mb_x=0;
1854     for(;;) {
1855         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1856         if (code < 0)
1857             return -1; /* error = end of slice, but empty slice is bad or?*/
1858         if (code >= 33) {
1859             if (code == 33) {
1860                 s->mb_x += 33;
1861             }
1862             /* otherwise, stuffing, nothing to do */
1863         } else {
1864             s->mb_x += code;
1865             break;
1866         }
1867     }
1868     s->mb_y = start_code;
1869     s->mb_incr= 1;
1870
1871     for(;;) {
1872         s->dsp.clear_blocks(s->block[0]);
1873         
1874         ret = mpeg_decode_mb(s, s->block);
1875         dprintf("ret=%d\n", ret);
1876         if (ret < 0)
1877             return -1;
1878         
1879         MPV_decode_mb(s, s->block);
1880
1881         if (++s->mb_x >= s->mb_width) {
1882             if(s->picture_structure==PICT_FRAME){
1883                 ff_draw_horiz_band(s, 16*s->mb_y, 16);
1884             }else{
1885                 if(!s->first_field){
1886                     ff_draw_horiz_band(s, 32*s->mb_y, 32);
1887                 }
1888             }
1889
1890             s->mb_x = 0;
1891             s->mb_y++;
1892             PRINT_QP("%s", "\n");
1893         }
1894         PRINT_QP("%2d", s->qscale);
1895
1896         /* skip mb handling */
1897         if (s->mb_incr == 0) {
1898             /* read again increment */
1899             s->mb_incr = 1;
1900             for(;;) {
1901                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1902                 if (code < 0)
1903                     goto eos; /* error = end of slice */
1904                 if (code >= 33) {
1905                     if (code == 33) {
1906                         s->mb_incr += 33;
1907                     }
1908                     /* otherwise, stuffing, nothing to do */
1909                 } else {
1910                     s->mb_incr += code;
1911                     break;
1912                 }
1913             }
1914         }
1915         if(s->mb_y<<field_pic >= s->mb_height){
1916             fprintf(stderr, "slice too long\n");
1917             return DECODE_SLICE_ERROR;
1918         }
1919     }
1920 eos: //end of slice
1921     
1922     emms_c();
1923 //intf("%d %d %d %d\n", s->mb_y, s->mb_height, s->pict_type, s->picture_number);
1924     /* end of slice reached */
1925     if (s->mb_y<<field_pic == s->mb_height && !s->first_field) {
1926         /* end of image */
1927
1928         if(s->mpeg2)
1929             s->qscale >>=1;
1930
1931         MPV_frame_end(s);
1932
1933         if (s->pict_type == B_TYPE || s->low_delay) {
1934             *pict= *(AVFrame*)&s->current_picture;
1935         } else {
1936             s->picture_number++;
1937             /* latency of 1 frame for I and P frames */
1938             /* XXX: use another variable than picture_number */
1939             if (s->last_picture_ptr == NULL) {
1940                 return DECODE_SLICE_OK;
1941             } else {
1942                 *pict= *(AVFrame*)&s->last_picture;
1943             }
1944         }
1945         return DECODE_SLICE_EOP;
1946     } else {
1947         return DECODE_SLICE_OK;
1948     }
1949 }
1950
1951 static int mpeg1_decode_sequence(AVCodecContext *avctx, 
1952                                  uint8_t *buf, int buf_size)
1953 {
1954     Mpeg1Context *s1 = avctx->priv_data;
1955     MpegEncContext *s = &s1->mpeg_enc_ctx;
1956     int width, height, i, v, j;
1957     float aspect;
1958
1959     init_get_bits(&s->gb, buf, buf_size*8);
1960
1961     width = get_bits(&s->gb, 12);
1962     height = get_bits(&s->gb, 12);
1963     s->aspect_ratio_info= get_bits(&s->gb, 4);
1964     if(!s->mpeg2){
1965         aspect= mpeg1_aspect[s->aspect_ratio_info];
1966         if(aspect!=0.0) avctx->aspect_ratio= width/(aspect*height);
1967     }
1968
1969     s->frame_rate_index = get_bits(&s->gb, 4);
1970     if (s->frame_rate_index == 0)
1971         return -1;
1972     s->bit_rate = get_bits(&s->gb, 18) * 400;
1973     if (get_bits1(&s->gb) == 0) /* marker */
1974         return -1;
1975     if (width <= 0 || height <= 0 ||
1976         (width % 2) != 0 || (height % 2) != 0)
1977         return -1;
1978     if (width != s->width ||
1979         height != s->height) {
1980         /* start new mpeg1 context decoding */
1981         s->out_format = FMT_MPEG1;
1982         if (s1->mpeg_enc_ctx_allocated) {
1983             MPV_common_end(s);
1984         }
1985         s->width = width;
1986         s->height = height;
1987         avctx->has_b_frames= 1;
1988         s->avctx = avctx;
1989         avctx->width = width;
1990         avctx->height = height;
1991         av_reduce(
1992             &avctx->frame_rate, 
1993             &avctx->frame_rate_base,
1994             frame_rate_tab[s->frame_rate_index],
1995             MPEG1_FRAME_RATE_BASE, //FIXME store in allready reduced form 
1996             1<<30
1997             );
1998         avctx->bit_rate = s->bit_rate;
1999         
2000         if (MPV_common_init(s) < 0)
2001             return -1;
2002         s1->mpeg_enc_ctx_allocated = 1;
2003     }
2004
2005     skip_bits(&s->gb, 10); /* vbv_buffer_size */
2006     skip_bits(&s->gb, 1);
2007
2008     /* get matrix */
2009     if (get_bits1(&s->gb)) {
2010         for(i=0;i<64;i++) {
2011             v = get_bits(&s->gb, 8);
2012             j = s->intra_scantable.permutated[i];
2013             s->intra_matrix[j] = v;
2014             s->chroma_intra_matrix[j] = v;
2015         }
2016 #ifdef DEBUG
2017         dprintf("intra matrix present\n");
2018         for(i=0;i<64;i++)
2019             dprintf(" %d", s->intra_matrix[s->intra_scantable.permutated[i]]);
2020         printf("\n");
2021 #endif
2022     } else {
2023         for(i=0;i<64;i++) {
2024             int j= s->dsp.idct_permutation[i];
2025             v = ff_mpeg1_default_intra_matrix[i];
2026             s->intra_matrix[j] = v;
2027             s->chroma_intra_matrix[j] = v;
2028         }
2029     }
2030     if (get_bits1(&s->gb)) {
2031         for(i=0;i<64;i++) {
2032             v = get_bits(&s->gb, 8);
2033             j = s->intra_scantable.permutated[i];
2034             s->inter_matrix[j] = v;
2035             s->chroma_inter_matrix[j] = v;
2036         }
2037 #ifdef DEBUG
2038         dprintf("non intra matrix present\n");
2039         for(i=0;i<64;i++)
2040             dprintf(" %d", s->inter_matrix[s->intra_scantable.permutated[i]]);
2041         printf("\n");
2042 #endif
2043     } else {
2044         for(i=0;i<64;i++) {
2045             int j= s->dsp.idct_permutation[i];
2046             v = ff_mpeg1_default_non_intra_matrix[i];
2047             s->inter_matrix[j] = v;
2048             s->chroma_inter_matrix[j] = v;
2049         }
2050     }
2051
2052     /* we set mpeg2 parameters so that it emulates mpeg1 */
2053     s->progressive_sequence = 1;
2054     s->progressive_frame = 1;
2055     s->picture_structure = PICT_FRAME;
2056     s->frame_pred_frame_dct = 1;
2057     s->mpeg2 = 0;
2058     avctx->sub_id = 1; /* indicates mpeg1 */
2059     return 0;
2060 }
2061
2062 static void mpeg_decode_user_data(AVCodecContext *avctx, 
2063                                   const uint8_t *buf, int buf_size)
2064 {
2065     const uint8_t *p;
2066     int len, flags;
2067     p = buf;
2068     len = buf_size;
2069
2070     /* we parse the DTG active format information */
2071     if (len >= 5 &&
2072         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2073         flags = p[4];
2074         p += 5;
2075         len -= 5;
2076         if (flags & 0x80) {
2077             /* skip event id */
2078             if (len < 2)
2079                 return;
2080             p += 2;
2081             len -= 2;
2082         }
2083         if (flags & 0x40) {
2084             if (len < 1)
2085                 return;
2086             avctx->dtg_active_format = p[0] & 0x0f;
2087         }
2088     }
2089 }
2090
2091 /* handle buffering and image synchronisation */
2092 static int mpeg_decode_frame(AVCodecContext *avctx, 
2093                              void *data, int *data_size,
2094                              uint8_t *buf, int buf_size)
2095 {
2096     Mpeg1Context *s = avctx->priv_data;
2097     uint8_t *buf_end, *buf_ptr, *buf_start;
2098     int len, start_code_found, ret, code, start_code, input_size;
2099     AVFrame *picture = data;
2100     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2101             
2102     dprintf("fill_buffer\n");
2103
2104     *data_size = 0;
2105
2106     /* special case for last picture */
2107     if (buf_size == 0) {
2108         if (s2->picture_number > 0) {
2109             *picture= *(AVFrame*)&s2->next_picture;
2110
2111             *data_size = sizeof(AVFrame);
2112         }
2113         return 0;
2114     }
2115
2116     buf_ptr = buf;
2117     buf_end = buf + buf_size;
2118
2119 #if 0    
2120     if (s->repeat_field % 2 == 1) { 
2121         s->repeat_field++;
2122         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2123         //        s2->picture_number, s->repeat_field);
2124         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2125             *data_size = sizeof(AVPicture);
2126             goto the_end;
2127         }
2128     }
2129 #endif
2130     while (buf_ptr < buf_end) {
2131         buf_start = buf_ptr;
2132         /* find start next code */
2133         code = find_start_code(&buf_ptr, buf_end, &s->header_state);
2134         if (code >= 0) {
2135             start_code_found = 1;
2136         } else {
2137             start_code_found = 0;
2138         }
2139         /* copy to buffer */
2140         len = buf_ptr - buf_start;
2141         if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
2142             /* data too big : flush */
2143             s->buf_ptr = s->buffer;
2144             if (start_code_found)
2145                 s->start_code = code;
2146         } else {
2147             memcpy(s->buf_ptr, buf_start, len);
2148             s->buf_ptr += len;
2149             if(   (!(s2->flags&CODEC_FLAG_TRUNCATED)) && (!start_code_found) 
2150                && s->buf_ptr+4<s->buffer+s->buffer_size){
2151                 start_code_found= 1;
2152                 code= 0x1FF;
2153                 s->header_state=0xFF;
2154                 s->buf_ptr[0]=0;
2155                 s->buf_ptr[1]=0;
2156                 s->buf_ptr[2]=1;
2157                 s->buf_ptr[3]=0xFF;
2158                 s->buf_ptr+=4;
2159             }
2160             if (start_code_found) {
2161                 /* prepare data for next start code */
2162                 input_size = s->buf_ptr - s->buffer;
2163                 start_code = s->start_code;
2164                 s->buf_ptr = s->buffer;
2165                 s->start_code = code;
2166                 switch(start_code) {
2167                 case SEQ_START_CODE:
2168                     mpeg1_decode_sequence(avctx, s->buffer, 
2169                                           input_size);
2170                     break;
2171                             
2172                 case PICTURE_START_CODE:
2173                     /* we have a complete image : we try to decompress it */
2174                     mpeg1_decode_picture(avctx, 
2175                                          s->buffer, input_size);
2176                     break;
2177                 case EXT_START_CODE:
2178                     mpeg_decode_extension(avctx,
2179                                           s->buffer, input_size);
2180                     break;
2181                 case USER_START_CODE:
2182                     mpeg_decode_user_data(avctx, 
2183                                           s->buffer, input_size);
2184                     break;
2185                 default:
2186                     if (start_code >= SLICE_MIN_START_CODE &&
2187                         start_code <= SLICE_MAX_START_CODE) {
2188                         
2189                         /* skip b frames if we dont have reference frames */
2190                         if(s2->last_picture_ptr==NULL && s2->pict_type==B_TYPE) break;
2191                         /* skip b frames if we are in a hurry */
2192                         if(avctx->hurry_up && s2->pict_type==B_TYPE) break;
2193                         /* skip everything if we are in a hurry>=5 */
2194                         if(avctx->hurry_up>=5) break;
2195
2196                         ret = mpeg_decode_slice(avctx, picture,
2197                                                 start_code, s->buffer, input_size);
2198
2199                         if (ret == DECODE_SLICE_EOP) {
2200                             *data_size = sizeof(AVPicture);
2201                             goto the_end;
2202                         }else if(ret<0){
2203                             fprintf(stderr,"Error while decoding slice\n");
2204                             if(ret==DECODE_SLICE_FATAL_ERROR) return -1;
2205                         }
2206                     }
2207                     break;
2208                 }
2209             }
2210         }
2211     }
2212  the_end:
2213     return buf_ptr - buf;
2214 }
2215
2216 static int mpeg_decode_end(AVCodecContext *avctx)
2217 {
2218     Mpeg1Context *s = avctx->priv_data;
2219
2220     if (s->mpeg_enc_ctx_allocated)
2221         MPV_common_end(&s->mpeg_enc_ctx);
2222     return 0;
2223 }
2224
2225 AVCodec mpeg_decoder = {
2226     "mpegvideo",
2227     CODEC_TYPE_VIDEO,
2228     CODEC_ID_MPEG1VIDEO,
2229     sizeof(Mpeg1Context),
2230     mpeg_decode_init,
2231     NULL,
2232     mpeg_decode_end,
2233     mpeg_decode_frame,
2234     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
2235 };