Making it easier to send arbitrary structures as work orders to MT workers
[ffmpeg.git] / libavcodec / mpeg12.c
1 /*
2  * MPEG-1/2 decoder
3  * Copyright (c) 2000,2001 Fabrice Bellard.
4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22
23 /**
24  * @file mpeg12.c
25  * MPEG-1/2 decoder
26  */
27
28 //#define DEBUG
29 #include "avcodec.h"
30 #include "dsputil.h"
31 #include "mpegvideo.h"
32
33 #include "mpeg12.h"
34 #include "mpeg12data.h"
35 #include "mpeg12decdata.h"
36 #include "bytestream.h"
37
38 //#undef NDEBUG
39 //#include <assert.h>
40
41
42 #define MV_VLC_BITS 9
43 #define MBINCR_VLC_BITS 9
44 #define MB_PAT_VLC_BITS 9
45 #define MB_PTYPE_VLC_BITS 6
46 #define MB_BTYPE_VLC_BITS 6
47
48 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
49                               DCTELEM *block,
50                               int n);
51 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
52                               DCTELEM *block,
53                               int n);
54 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n);
55 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
56                                         DCTELEM *block,
57                                         int n);
58 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
59                                     DCTELEM *block,
60                                     int n);
61 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, DCTELEM *block, int n);
62 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
63 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
64 static void exchange_uv(MpegEncContext *s);
65
66 extern int XVMC_field_start(MpegEncContext *s, AVCodecContext *avctx);
67 extern int XVMC_field_end(MpegEncContext *s);
68 extern void XVMC_pack_pblocks(MpegEncContext *s,int cbp);
69 extern void XVMC_init_block(MpegEncContext *s);//set s->block
70
71 static const enum PixelFormat pixfmt_xvmc_mpg2_420[] = {
72                                            PIX_FMT_XVMC_MPEG2_IDCT,
73                                            PIX_FMT_XVMC_MPEG2_MC,
74                                            PIX_FMT_NONE};
75
76 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
77
78
79 #define INIT_2D_VLC_RL(rl, static_size)\
80 {\
81     static RL_VLC_ELEM rl_vlc_table[static_size];\
82     INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\
83              &rl.table_vlc[0][1], 4, 2,\
84              &rl.table_vlc[0][0], 4, 2, static_size);\
85 \
86     rl.rl_vlc[0]= rl_vlc_table;\
87     init_2d_vlc_rl(&rl);\
88 }
89
90 static void init_2d_vlc_rl(RLTable *rl)
91 {
92     int i;
93
94     for(i=0; i<rl->vlc.table_size; i++){
95         int code= rl->vlc.table[i][0];
96         int len = rl->vlc.table[i][1];
97         int level, run;
98
99         if(len==0){ // illegal code
100             run= 65;
101             level= MAX_LEVEL;
102         }else if(len<0){ //more bits needed
103             run= 0;
104             level= code;
105         }else{
106             if(code==rl->n){ //esc
107                 run= 65;
108                 level= 0;
109             }else if(code==rl->n+1){ //eob
110                 run= 0;
111                 level= 127;
112             }else{
113                 run=   rl->table_run  [code] + 1;
114                 level= rl->table_level[code];
115             }
116         }
117         rl->rl_vlc[0][i].len= len;
118         rl->rl_vlc[0][i].level= level;
119         rl->rl_vlc[0][i].run= run;
120     }
121 }
122
123 void ff_mpeg12_common_init(MpegEncContext *s)
124 {
125
126     s->y_dc_scale_table=
127     s->c_dc_scale_table= mpeg2_dc_scale_table[s->intra_dc_precision];
128
129 }
130
131 void ff_mpeg1_clean_buffers(MpegEncContext *s){
132     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
133     s->last_dc[1] = s->last_dc[0];
134     s->last_dc[2] = s->last_dc[0];
135     memset(s->last_mv, 0, sizeof(s->last_mv));
136 }
137
138
139 /******************************************/
140 /* decoding */
141
142 static VLC mv_vlc;
143 static VLC mbincr_vlc;
144 static VLC mb_ptype_vlc;
145 static VLC mb_btype_vlc;
146 static VLC mb_pat_vlc;
147
148 av_cold void ff_mpeg12_init_vlcs(void)
149 {
150     static int done = 0;
151
152     if (!done) {
153         done = 1;
154
155         INIT_VLC_STATIC(&dc_lum_vlc, DC_VLC_BITS, 12,
156                  ff_mpeg12_vlc_dc_lum_bits, 1, 1,
157                  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
158         INIT_VLC_STATIC(&dc_chroma_vlc,  DC_VLC_BITS, 12,
159                  ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
160                  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
161         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 17,
162                  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
163                  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
164         INIT_VLC_STATIC(&mbincr_vlc, MBINCR_VLC_BITS, 36,
165                  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
166                  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
167         INIT_VLC_STATIC(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
168                  &ff_mpeg12_mbPatTable[0][1], 2, 1,
169                  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
170
171         INIT_VLC_STATIC(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
172                  &table_mb_ptype[0][1], 2, 1,
173                  &table_mb_ptype[0][0], 2, 1, 64);
174         INIT_VLC_STATIC(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
175                  &table_mb_btype[0][1], 2, 1,
176                  &table_mb_btype[0][0], 2, 1, 64);
177         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
178         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
179
180         INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
181         INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
182     }
183 }
184
185 static inline int get_dmv(MpegEncContext *s)
186 {
187     if(get_bits1(&s->gb))
188         return 1 - (get_bits1(&s->gb) << 1);
189     else
190         return 0;
191 }
192
193 static inline int get_qscale(MpegEncContext *s)
194 {
195     int qscale = get_bits(&s->gb, 5);
196     if (s->q_scale_type) {
197         return non_linear_qscale[qscale];
198     } else {
199         return qscale << 1;
200     }
201 }
202
203 /* motion type (for MPEG-2) */
204 #define MT_FIELD 1
205 #define MT_FRAME 2
206 #define MT_16X8  2
207 #define MT_DMV   3
208
209 static int mpeg_decode_mb(MpegEncContext *s,
210                           DCTELEM block[12][64])
211 {
212     int i, j, k, cbp, val, mb_type, motion_type;
213     const int mb_block_count = 4 + (1<< s->chroma_format);
214
215     dprintf(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
216
217     assert(s->mb_skipped==0);
218
219     if (s->mb_skip_run-- != 0) {
220         if (s->pict_type == FF_P_TYPE) {
221             s->mb_skipped = 1;
222             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
223         } else {
224             int mb_type;
225
226             if(s->mb_x)
227                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
228             else
229                 mb_type= s->current_picture.mb_type[ s->mb_width + (s->mb_y-1)*s->mb_stride - 1]; // FIXME not sure if this is allowed in MPEG at all
230             if(IS_INTRA(mb_type))
231                 return -1;
232
233             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
234                 mb_type | MB_TYPE_SKIP;
235 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
236
237             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
238                 s->mb_skipped = 1;
239         }
240
241         return 0;
242     }
243
244     switch(s->pict_type) {
245     default:
246     case FF_I_TYPE:
247         if (get_bits1(&s->gb) == 0) {
248             if (get_bits1(&s->gb) == 0){
249                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
250                 return -1;
251             }
252             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
253         } else {
254             mb_type = MB_TYPE_INTRA;
255         }
256         break;
257     case FF_P_TYPE:
258         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
259         if (mb_type < 0){
260             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
261             return -1;
262         }
263         mb_type = ptype2mb_type[ mb_type ];
264         break;
265     case FF_B_TYPE:
266         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
267         if (mb_type < 0){
268             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
269             return -1;
270         }
271         mb_type = btype2mb_type[ mb_type ];
272         break;
273     }
274     dprintf(s->avctx, "mb_type=%x\n", mb_type);
275 //    motion_type = 0; /* avoid warning */
276     if (IS_INTRA(mb_type)) {
277         s->dsp.clear_blocks(s->block[0]);
278
279         if(!s->chroma_y_shift){
280             s->dsp.clear_blocks(s->block[6]);
281         }
282
283         /* compute DCT type */
284         if (s->picture_structure == PICT_FRAME && //FIXME add an interlaced_dct coded var?
285             !s->frame_pred_frame_dct) {
286             s->interlaced_dct = get_bits1(&s->gb);
287         }
288
289         if (IS_QUANT(mb_type))
290             s->qscale = get_qscale(s);
291
292         if (s->concealment_motion_vectors) {
293             /* just parse them */
294             if (s->picture_structure != PICT_FRAME)
295                 skip_bits1(&s->gb); /* field select */
296
297             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
298                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
299             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
300                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
301
302             skip_bits1(&s->gb); /* marker */
303         }else
304             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
305         s->mb_intra = 1;
306 #ifdef HAVE_XVMC
307         //if 1, we memcpy blocks in xvmcvideo
308         if(s->avctx->xvmc_acceleration > 1){
309             XVMC_pack_pblocks(s,-1);//inter are always full blocks
310             if(s->swap_uv){
311                 exchange_uv(s);
312             }
313         }
314 #endif
315
316         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
317             if(s->flags2 & CODEC_FLAG2_FAST){
318                 for(i=0;i<6;i++) {
319                     mpeg2_fast_decode_block_intra(s, s->pblocks[i], i);
320                 }
321             }else{
322                 for(i=0;i<mb_block_count;i++) {
323                     if (mpeg2_decode_block_intra(s, s->pblocks[i], i) < 0)
324                         return -1;
325                 }
326             }
327         } else {
328             for(i=0;i<6;i++) {
329                 if (mpeg1_decode_block_intra(s, s->pblocks[i], i) < 0)
330                     return -1;
331             }
332         }
333     } else {
334         if (mb_type & MB_TYPE_ZERO_MV){
335             assert(mb_type & MB_TYPE_CBP);
336
337             s->mv_dir = MV_DIR_FORWARD;
338             if(s->picture_structure == PICT_FRAME){
339                 if(!s->frame_pred_frame_dct)
340                     s->interlaced_dct = get_bits1(&s->gb);
341                 s->mv_type = MV_TYPE_16X16;
342             }else{
343                 s->mv_type = MV_TYPE_FIELD;
344                 mb_type |= MB_TYPE_INTERLACED;
345                 s->field_select[0][0]= s->picture_structure - 1;
346             }
347
348             if (IS_QUANT(mb_type))
349                 s->qscale = get_qscale(s);
350
351             s->last_mv[0][0][0] = 0;
352             s->last_mv[0][0][1] = 0;
353             s->last_mv[0][1][0] = 0;
354             s->last_mv[0][1][1] = 0;
355             s->mv[0][0][0] = 0;
356             s->mv[0][0][1] = 0;
357         }else{
358             assert(mb_type & MB_TYPE_L0L1);
359 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
360             /* get additional motion vector type */
361             if (s->frame_pred_frame_dct)
362                 motion_type = MT_FRAME;
363             else{
364                 motion_type = get_bits(&s->gb, 2);
365                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
366                     s->interlaced_dct = get_bits1(&s->gb);
367             }
368
369             if (IS_QUANT(mb_type))
370                 s->qscale = get_qscale(s);
371
372             /* motion vectors */
373             s->mv_dir= (mb_type>>13)&3;
374             dprintf(s->avctx, "motion_type=%d\n", motion_type);
375             switch(motion_type) {
376             case MT_FRAME: /* or MT_16X8 */
377                 if (s->picture_structure == PICT_FRAME) {
378                     mb_type |= MB_TYPE_16x16;
379                     s->mv_type = MV_TYPE_16X16;
380                     for(i=0;i<2;i++) {
381                         if (USES_LIST(mb_type, i)) {
382                             /* MT_FRAME */
383                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
384                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
385                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
386                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
387                             /* full_pel: only for MPEG-1 */
388                             if (s->full_pel[i]){
389                                 s->mv[i][0][0] <<= 1;
390                                 s->mv[i][0][1] <<= 1;
391                             }
392                         }
393                     }
394                 } else {
395                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
396                     s->mv_type = MV_TYPE_16X8;
397                     for(i=0;i<2;i++) {
398                         if (USES_LIST(mb_type, i)) {
399                             /* MT_16X8 */
400                             for(j=0;j<2;j++) {
401                                 s->field_select[i][j] = get_bits1(&s->gb);
402                                 for(k=0;k<2;k++) {
403                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
404                                                              s->last_mv[i][j][k]);
405                                     s->last_mv[i][j][k] = val;
406                                     s->mv[i][j][k] = val;
407                                 }
408                             }
409                         }
410                     }
411                 }
412                 break;
413             case MT_FIELD:
414                 s->mv_type = MV_TYPE_FIELD;
415                 if (s->picture_structure == PICT_FRAME) {
416                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
417                     for(i=0;i<2;i++) {
418                         if (USES_LIST(mb_type, i)) {
419                             for(j=0;j<2;j++) {
420                                 s->field_select[i][j] = get_bits1(&s->gb);
421                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
422                                                          s->last_mv[i][j][0]);
423                                 s->last_mv[i][j][0] = val;
424                                 s->mv[i][j][0] = val;
425                                 dprintf(s->avctx, "fmx=%d\n", val);
426                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
427                                                          s->last_mv[i][j][1] >> 1);
428                                 s->last_mv[i][j][1] = val << 1;
429                                 s->mv[i][j][1] = val;
430                                 dprintf(s->avctx, "fmy=%d\n", val);
431                             }
432                         }
433                     }
434                 } else {
435                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
436                     for(i=0;i<2;i++) {
437                         if (USES_LIST(mb_type, i)) {
438                             s->field_select[i][0] = get_bits1(&s->gb);
439                             for(k=0;k<2;k++) {
440                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
441                                                          s->last_mv[i][0][k]);
442                                 s->last_mv[i][0][k] = val;
443                                 s->last_mv[i][1][k] = val;
444                                 s->mv[i][0][k] = val;
445                             }
446                         }
447                     }
448                 }
449                 break;
450             case MT_DMV:
451                 s->mv_type = MV_TYPE_DMV;
452                 for(i=0;i<2;i++) {
453                     if (USES_LIST(mb_type, i)) {
454                         int dmx, dmy, mx, my, m;
455                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
456                                                 s->last_mv[i][0][0]);
457                         s->last_mv[i][0][0] = mx;
458                         s->last_mv[i][1][0] = mx;
459                         dmx = get_dmv(s);
460                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
461                                                 s->last_mv[i][0][1] >> 1);
462                         dmy = get_dmv(s);
463
464
465                         s->last_mv[i][0][1] = my<<1;
466                         s->last_mv[i][1][1] = my<<1;
467
468                         s->mv[i][0][0] = mx;
469                         s->mv[i][0][1] = my;
470                         s->mv[i][1][0] = mx;//not used
471                         s->mv[i][1][1] = my;//not used
472
473                         if (s->picture_structure == PICT_FRAME) {
474                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
475
476                             //m = 1 + 2 * s->top_field_first;
477                             m = s->top_field_first ? 1 : 3;
478
479                             /* top -> top pred */
480                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
481                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
482                             m = 4 - m;
483                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
484                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
485                         } else {
486                             mb_type |= MB_TYPE_16x16;
487
488                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
489                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
490                             if(s->picture_structure == PICT_TOP_FIELD)
491                                 s->mv[i][2][1]--;
492                             else
493                                 s->mv[i][2][1]++;
494                         }
495                     }
496                 }
497                 break;
498             default:
499                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
500                 return -1;
501             }
502         }
503
504         s->mb_intra = 0;
505         if (HAS_CBP(mb_type)) {
506             s->dsp.clear_blocks(s->block[0]);
507
508             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
509             if(mb_block_count > 6){
510                  cbp<<= mb_block_count-6;
511                  cbp |= get_bits(&s->gb, mb_block_count-6);
512                  s->dsp.clear_blocks(s->block[6]);
513             }
514             if (cbp <= 0){
515                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
516                 return -1;
517             }
518
519 #ifdef HAVE_XVMC
520             //if 1, we memcpy blocks in xvmcvideo
521             if(s->avctx->xvmc_acceleration > 1){
522                 XVMC_pack_pblocks(s,cbp);
523                 if(s->swap_uv){
524                     exchange_uv(s);
525                 }
526             }
527 #endif
528
529             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
530                 if(s->flags2 & CODEC_FLAG2_FAST){
531                     for(i=0;i<6;i++) {
532                         if(cbp & 32) {
533                             mpeg2_fast_decode_block_non_intra(s, s->pblocks[i], i);
534                         } else {
535                             s->block_last_index[i] = -1;
536                         }
537                         cbp+=cbp;
538                     }
539                 }else{
540                     cbp<<= 12-mb_block_count;
541
542                     for(i=0;i<mb_block_count;i++) {
543                         if ( cbp & (1<<11) ) {
544                             if (mpeg2_decode_block_non_intra(s, s->pblocks[i], i) < 0)
545                                 return -1;
546                         } else {
547                             s->block_last_index[i] = -1;
548                         }
549                         cbp+=cbp;
550                     }
551                 }
552             } else {
553                 if(s->flags2 & CODEC_FLAG2_FAST){
554                     for(i=0;i<6;i++) {
555                         if (cbp & 32) {
556                             mpeg1_fast_decode_block_inter(s, s->pblocks[i], i);
557                         } else {
558                             s->block_last_index[i] = -1;
559                         }
560                         cbp+=cbp;
561                     }
562                 }else{
563                     for(i=0;i<6;i++) {
564                         if (cbp & 32) {
565                             if (mpeg1_decode_block_inter(s, s->pblocks[i], i) < 0)
566                                 return -1;
567                         } else {
568                             s->block_last_index[i] = -1;
569                         }
570                         cbp+=cbp;
571                     }
572                 }
573             }
574         }else{
575             for(i=0;i<12;i++)
576                 s->block_last_index[i] = -1;
577         }
578     }
579
580     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
581
582     return 0;
583 }
584
585 /* as H.263, but only 17 codes */
586 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
587 {
588     int code, sign, val, l, shift;
589
590     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
591     if (code == 0) {
592         return pred;
593     }
594     if (code < 0) {
595         return 0xffff;
596     }
597
598     sign = get_bits1(&s->gb);
599     shift = fcode - 1;
600     val = code;
601     if (shift) {
602         val = (val - 1) << shift;
603         val |= get_bits(&s->gb, shift);
604         val++;
605     }
606     if (sign)
607         val = -val;
608     val += pred;
609
610     /* modulo decoding */
611     l= INT_BIT - 5 - shift;
612     val = (val<<l)>>l;
613     return val;
614 }
615
616 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
617                                DCTELEM *block,
618                                int n)
619 {
620     int level, dc, diff, i, j, run;
621     int component;
622     RLTable *rl = &ff_rl_mpeg1;
623     uint8_t * const scantable= s->intra_scantable.permutated;
624     const uint16_t *quant_matrix= s->intra_matrix;
625     const int qscale= s->qscale;
626
627     /* DC coefficient */
628     component = (n <= 3 ? 0 : n - 4 + 1);
629     diff = decode_dc(&s->gb, component);
630     if (diff >= 0xffff)
631         return -1;
632     dc = s->last_dc[component];
633     dc += diff;
634     s->last_dc[component] = dc;
635     block[0] = dc<<3;
636     dprintf(s->avctx, "dc=%d diff=%d\n", dc, diff);
637     i = 0;
638     {
639         OPEN_READER(re, &s->gb);
640         /* now quantify & encode AC coefficients */
641         for(;;) {
642             UPDATE_CACHE(re, &s->gb);
643             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
644
645             if(level == 127){
646                 break;
647             } else if(level != 0) {
648                 i += run;
649                 j = scantable[i];
650                 level= (level*qscale*quant_matrix[j])>>4;
651                 level= (level-1)|1;
652                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
653                 LAST_SKIP_BITS(re, &s->gb, 1);
654             } else {
655                 /* escape */
656                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
657                 UPDATE_CACHE(re, &s->gb);
658                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
659                 if (level == -128) {
660                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
661                 } else if (level == 0) {
662                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
663                 }
664                 i += run;
665                 j = scantable[i];
666                 if(level<0){
667                     level= -level;
668                     level= (level*qscale*quant_matrix[j])>>4;
669                     level= (level-1)|1;
670                     level= -level;
671                 }else{
672                     level= (level*qscale*quant_matrix[j])>>4;
673                     level= (level-1)|1;
674                 }
675             }
676             if (i > 63){
677                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
678                 return -1;
679             }
680
681             block[j] = level;
682         }
683         CLOSE_READER(re, &s->gb);
684     }
685     s->block_last_index[n] = i;
686    return 0;
687 }
688
689 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
690                                DCTELEM *block,
691                                int n)
692 {
693     int level, i, j, run;
694     RLTable *rl = &ff_rl_mpeg1;
695     uint8_t * const scantable= s->intra_scantable.permutated;
696     const uint16_t *quant_matrix= s->inter_matrix;
697     const int qscale= s->qscale;
698
699     {
700         OPEN_READER(re, &s->gb);
701         i = -1;
702         // special case for first coefficient, no need to add second VLC table
703         UPDATE_CACHE(re, &s->gb);
704         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
705             level= (3*qscale*quant_matrix[0])>>5;
706             level= (level-1)|1;
707             if(GET_CACHE(re, &s->gb)&0x40000000)
708                 level= -level;
709             block[0] = level;
710             i++;
711             SKIP_BITS(re, &s->gb, 2);
712             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
713                 goto end;
714         }
715 #if MIN_CACHE_BITS < 19
716         UPDATE_CACHE(re, &s->gb);
717 #endif
718         /* now quantify & encode AC coefficients */
719         for(;;) {
720             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
721
722             if(level != 0) {
723                 i += run;
724                 j = scantable[i];
725                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
726                 level= (level-1)|1;
727                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
728                 SKIP_BITS(re, &s->gb, 1);
729             } else {
730                 /* escape */
731                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
732                 UPDATE_CACHE(re, &s->gb);
733                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
734                 if (level == -128) {
735                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
736                 } else if (level == 0) {
737                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
738                 }
739                 i += run;
740                 j = scantable[i];
741                 if(level<0){
742                     level= -level;
743                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
744                     level= (level-1)|1;
745                     level= -level;
746                 }else{
747                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
748                     level= (level-1)|1;
749                 }
750             }
751             if (i > 63){
752                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
753                 return -1;
754             }
755
756             block[j] = level;
757 #if MIN_CACHE_BITS < 19
758             UPDATE_CACHE(re, &s->gb);
759 #endif
760             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
761                 break;
762 #if MIN_CACHE_BITS >= 19
763             UPDATE_CACHE(re, &s->gb);
764 #endif
765         }
766 end:
767         LAST_SKIP_BITS(re, &s->gb, 2);
768         CLOSE_READER(re, &s->gb);
769     }
770     s->block_last_index[n] = i;
771     return 0;
772 }
773
774 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
775 {
776     int level, i, j, run;
777     RLTable *rl = &ff_rl_mpeg1;
778     uint8_t * const scantable= s->intra_scantable.permutated;
779     const int qscale= s->qscale;
780
781     {
782         OPEN_READER(re, &s->gb);
783         i = -1;
784         // special case for first coefficient, no need to add second VLC table
785         UPDATE_CACHE(re, &s->gb);
786         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
787             level= (3*qscale)>>1;
788             level= (level-1)|1;
789             if(GET_CACHE(re, &s->gb)&0x40000000)
790                 level= -level;
791             block[0] = level;
792             i++;
793             SKIP_BITS(re, &s->gb, 2);
794             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
795                 goto end;
796         }
797 #if MIN_CACHE_BITS < 19
798         UPDATE_CACHE(re, &s->gb);
799 #endif
800
801         /* now quantify & encode AC coefficients */
802         for(;;) {
803             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
804
805             if(level != 0) {
806                 i += run;
807                 j = scantable[i];
808                 level= ((level*2+1)*qscale)>>1;
809                 level= (level-1)|1;
810                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
811                 SKIP_BITS(re, &s->gb, 1);
812             } else {
813                 /* escape */
814                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
815                 UPDATE_CACHE(re, &s->gb);
816                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
817                 if (level == -128) {
818                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
819                 } else if (level == 0) {
820                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
821                 }
822                 i += run;
823                 j = scantable[i];
824                 if(level<0){
825                     level= -level;
826                     level= ((level*2+1)*qscale)>>1;
827                     level= (level-1)|1;
828                     level= -level;
829                 }else{
830                     level= ((level*2+1)*qscale)>>1;
831                     level= (level-1)|1;
832                 }
833             }
834
835             block[j] = level;
836 #if MIN_CACHE_BITS < 19
837             UPDATE_CACHE(re, &s->gb);
838 #endif
839             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
840                 break;
841 #if MIN_CACHE_BITS >= 19
842             UPDATE_CACHE(re, &s->gb);
843 #endif
844         }
845 end:
846         LAST_SKIP_BITS(re, &s->gb, 2);
847         CLOSE_READER(re, &s->gb);
848     }
849     s->block_last_index[n] = i;
850     return 0;
851 }
852
853
854 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
855                                DCTELEM *block,
856                                int n)
857 {
858     int level, i, j, run;
859     RLTable *rl = &ff_rl_mpeg1;
860     uint8_t * const scantable= s->intra_scantable.permutated;
861     const uint16_t *quant_matrix;
862     const int qscale= s->qscale;
863     int mismatch;
864
865     mismatch = 1;
866
867     {
868         OPEN_READER(re, &s->gb);
869         i = -1;
870         if (n < 4)
871             quant_matrix = s->inter_matrix;
872         else
873             quant_matrix = s->chroma_inter_matrix;
874
875         // special case for first coefficient, no need to add second VLC table
876         UPDATE_CACHE(re, &s->gb);
877         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
878             level= (3*qscale*quant_matrix[0])>>5;
879             if(GET_CACHE(re, &s->gb)&0x40000000)
880                 level= -level;
881             block[0] = level;
882             mismatch ^= level;
883             i++;
884             SKIP_BITS(re, &s->gb, 2);
885             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
886                 goto end;
887         }
888 #if MIN_CACHE_BITS < 19
889         UPDATE_CACHE(re, &s->gb);
890 #endif
891
892         /* now quantify & encode AC coefficients */
893         for(;;) {
894             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
895
896             if(level != 0) {
897                 i += run;
898                 j = scantable[i];
899                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
900                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
901                 SKIP_BITS(re, &s->gb, 1);
902             } else {
903                 /* escape */
904                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
905                 UPDATE_CACHE(re, &s->gb);
906                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
907
908                 i += run;
909                 j = scantable[i];
910                 if(level<0){
911                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
912                     level= -level;
913                 }else{
914                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
915                 }
916             }
917             if (i > 63){
918                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
919                 return -1;
920             }
921
922             mismatch ^= level;
923             block[j] = level;
924 #if MIN_CACHE_BITS < 19
925             UPDATE_CACHE(re, &s->gb);
926 #endif
927             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
928                 break;
929 #if MIN_CACHE_BITS >= 19
930             UPDATE_CACHE(re, &s->gb);
931 #endif
932         }
933 end:
934         LAST_SKIP_BITS(re, &s->gb, 2);
935         CLOSE_READER(re, &s->gb);
936     }
937     block[63] ^= (mismatch & 1);
938
939     s->block_last_index[n] = i;
940     return 0;
941 }
942
943 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
944                                DCTELEM *block,
945                                int n)
946 {
947     int level, i, j, run;
948     RLTable *rl = &ff_rl_mpeg1;
949     uint8_t * const scantable= s->intra_scantable.permutated;
950     const int qscale= s->qscale;
951     OPEN_READER(re, &s->gb);
952     i = -1;
953
954     // special case for first coefficient, no need to add second VLC table
955     UPDATE_CACHE(re, &s->gb);
956     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
957         level= (3*qscale)>>1;
958         if(GET_CACHE(re, &s->gb)&0x40000000)
959             level= -level;
960         block[0] = level;
961         i++;
962         SKIP_BITS(re, &s->gb, 2);
963         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
964             goto end;
965     }
966 #if MIN_CACHE_BITS < 19
967     UPDATE_CACHE(re, &s->gb);
968 #endif
969
970     /* now quantify & encode AC coefficients */
971     for(;;) {
972         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
973
974         if(level != 0) {
975             i += run;
976             j = scantable[i];
977             level= ((level*2+1)*qscale)>>1;
978             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
979             SKIP_BITS(re, &s->gb, 1);
980         } else {
981             /* escape */
982             run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
983             UPDATE_CACHE(re, &s->gb);
984             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
985
986             i += run;
987             j = scantable[i];
988             if(level<0){
989                 level= ((-level*2+1)*qscale)>>1;
990                 level= -level;
991             }else{
992                 level= ((level*2+1)*qscale)>>1;
993             }
994         }
995
996         block[j] = level;
997 #if MIN_CACHE_BITS < 19
998         UPDATE_CACHE(re, &s->gb);
999 #endif
1000         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
1001             break;
1002 #if MIN_CACHE_BITS >=19
1003         UPDATE_CACHE(re, &s->gb);
1004 #endif
1005     }
1006 end:
1007     LAST_SKIP_BITS(re, &s->gb, 2);
1008     CLOSE_READER(re, &s->gb);
1009     s->block_last_index[n] = i;
1010     return 0;
1011 }
1012
1013
1014 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1015                                DCTELEM *block,
1016                                int n)
1017 {
1018     int level, dc, diff, i, j, run;
1019     int component;
1020     RLTable *rl;
1021     uint8_t * const scantable= s->intra_scantable.permutated;
1022     const uint16_t *quant_matrix;
1023     const int qscale= s->qscale;
1024     int mismatch;
1025
1026     /* DC coefficient */
1027     if (n < 4){
1028         quant_matrix = s->intra_matrix;
1029         component = 0;
1030     }else{
1031         quant_matrix = s->chroma_intra_matrix;
1032         component = (n&1) + 1;
1033     }
1034     diff = decode_dc(&s->gb, component);
1035     if (diff >= 0xffff)
1036         return -1;
1037     dc = s->last_dc[component];
1038     dc += diff;
1039     s->last_dc[component] = dc;
1040     block[0] = dc << (3 - s->intra_dc_precision);
1041     dprintf(s->avctx, "dc=%d\n", block[0]);
1042     mismatch = block[0] ^ 1;
1043     i = 0;
1044     if (s->intra_vlc_format)
1045         rl = &ff_rl_mpeg2;
1046     else
1047         rl = &ff_rl_mpeg1;
1048
1049     {
1050         OPEN_READER(re, &s->gb);
1051         /* now quantify & encode AC coefficients */
1052         for(;;) {
1053             UPDATE_CACHE(re, &s->gb);
1054             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1055
1056             if(level == 127){
1057                 break;
1058             } else if(level != 0) {
1059                 i += run;
1060                 j = scantable[i];
1061                 level= (level*qscale*quant_matrix[j])>>4;
1062                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1063                 LAST_SKIP_BITS(re, &s->gb, 1);
1064             } else {
1065                 /* escape */
1066                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1067                 UPDATE_CACHE(re, &s->gb);
1068                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1069                 i += run;
1070                 j = scantable[i];
1071                 if(level<0){
1072                     level= (-level*qscale*quant_matrix[j])>>4;
1073                     level= -level;
1074                 }else{
1075                     level= (level*qscale*quant_matrix[j])>>4;
1076                 }
1077             }
1078             if (i > 63){
1079                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1080                 return -1;
1081             }
1082
1083             mismatch^= level;
1084             block[j] = level;
1085         }
1086         CLOSE_READER(re, &s->gb);
1087     }
1088     block[63]^= mismatch&1;
1089
1090     s->block_last_index[n] = i;
1091     return 0;
1092 }
1093
1094 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
1095                                DCTELEM *block,
1096                                int n)
1097 {
1098     int level, dc, diff, j, run;
1099     int component;
1100     RLTable *rl;
1101     uint8_t * scantable= s->intra_scantable.permutated;
1102     const uint16_t *quant_matrix;
1103     const int qscale= s->qscale;
1104
1105     /* DC coefficient */
1106     if (n < 4){
1107         quant_matrix = s->intra_matrix;
1108         component = 0;
1109     }else{
1110         quant_matrix = s->chroma_intra_matrix;
1111         component = (n&1) + 1;
1112     }
1113     diff = decode_dc(&s->gb, component);
1114     if (diff >= 0xffff)
1115         return -1;
1116     dc = s->last_dc[component];
1117     dc += diff;
1118     s->last_dc[component] = dc;
1119     block[0] = dc << (3 - s->intra_dc_precision);
1120     if (s->intra_vlc_format)
1121         rl = &ff_rl_mpeg2;
1122     else
1123         rl = &ff_rl_mpeg1;
1124
1125     {
1126         OPEN_READER(re, &s->gb);
1127         /* now quantify & encode AC coefficients */
1128         for(;;) {
1129             UPDATE_CACHE(re, &s->gb);
1130             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1131
1132             if(level == 127){
1133                 break;
1134             } else if(level != 0) {
1135                 scantable += run;
1136                 j = *scantable;
1137                 level= (level*qscale*quant_matrix[j])>>4;
1138                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1139                 LAST_SKIP_BITS(re, &s->gb, 1);
1140             } else {
1141                 /* escape */
1142                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1143                 UPDATE_CACHE(re, &s->gb);
1144                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1145                 scantable += run;
1146                 j = *scantable;
1147                 if(level<0){
1148                     level= (-level*qscale*quant_matrix[j])>>4;
1149                     level= -level;
1150                 }else{
1151                     level= (level*qscale*quant_matrix[j])>>4;
1152                 }
1153             }
1154
1155             block[j] = level;
1156         }
1157         CLOSE_READER(re, &s->gb);
1158     }
1159
1160     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
1161     return 0;
1162 }
1163
1164 typedef struct Mpeg1Context {
1165     MpegEncContext mpeg_enc_ctx;
1166     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1167     int repeat_field; /* true if we must repeat the field */
1168     AVPanScan pan_scan; /** some temporary storage for the panscan */
1169     int slice_count;
1170     int swap_uv;//indicate VCR2
1171     int save_aspect_info;
1172     int save_width, save_height;
1173     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1174
1175 } Mpeg1Context;
1176
1177 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1178 {
1179     Mpeg1Context *s = avctx->priv_data;
1180     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1181     int i;
1182
1183     /* we need some permutation to store matrices,
1184      * until MPV_common_init() sets the real permutation. */
1185     for(i=0;i<64;i++)
1186        s2->dsp.idct_permutation[i]=i;
1187
1188     MPV_decode_defaults(s2);
1189
1190     s->mpeg_enc_ctx.avctx= avctx;
1191     s->mpeg_enc_ctx.flags= avctx->flags;
1192     s->mpeg_enc_ctx.flags2= avctx->flags2;
1193     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1194     ff_mpeg12_init_vlcs();
1195
1196     s->mpeg_enc_ctx_allocated = 0;
1197     s->mpeg_enc_ctx.picture_number = 0;
1198     s->repeat_field = 0;
1199     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1200     return 0;
1201 }
1202
1203 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1204                                      const uint8_t *new_perm){
1205     uint16_t temp_matrix[64];
1206     int i;
1207
1208     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1209
1210     for(i=0;i<64;i++){
1211         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1212     }
1213 }
1214
1215 /* Call this function when we know all parameters.
1216  * It may be called in different places for MPEG-1 and MPEG-2. */
1217 static int mpeg_decode_postinit(AVCodecContext *avctx){
1218     Mpeg1Context *s1 = avctx->priv_data;
1219     MpegEncContext *s = &s1->mpeg_enc_ctx;
1220     uint8_t old_permutation[64];
1221
1222     if (
1223         (s1->mpeg_enc_ctx_allocated == 0)||
1224         avctx->coded_width  != s->width ||
1225         avctx->coded_height != s->height||
1226         s1->save_width != s->width ||
1227         s1->save_height != s->height ||
1228         s1->save_aspect_info != s->aspect_ratio_info||
1229         0)
1230     {
1231
1232         if (s1->mpeg_enc_ctx_allocated) {
1233             ParseContext pc= s->parse_context;
1234             s->parse_context.buffer=0;
1235             MPV_common_end(s);
1236             s->parse_context= pc;
1237         }
1238
1239         if( (s->width == 0 )||(s->height == 0))
1240             return -2;
1241
1242         avcodec_set_dimensions(avctx, s->width, s->height);
1243         avctx->bit_rate = s->bit_rate;
1244         s1->save_aspect_info = s->aspect_ratio_info;
1245         s1->save_width = s->width;
1246         s1->save_height = s->height;
1247
1248         /* low_delay may be forced, in this case we will have B-frames
1249          * that behave like P-frames. */
1250         avctx->has_b_frames = !(s->low_delay);
1251
1252         if(avctx->sub_id==1){//s->codec_id==avctx->codec_id==CODEC_ID
1253             //MPEG-1 fps
1254             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1255             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1256             //MPEG-1 aspect
1257             avctx->sample_aspect_ratio= av_d2q(
1258                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1259
1260         }else{//MPEG-2
1261         //MPEG-2 fps
1262             av_reduce(
1263                 &s->avctx->time_base.den,
1264                 &s->avctx->time_base.num,
1265                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1266                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1267                 1<<30);
1268         //MPEG-2 aspect
1269             if(s->aspect_ratio_info > 1){
1270                 //we ignore the spec here as reality does not match the spec, see for example
1271                 // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
1272                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) || 1){
1273                     s->avctx->sample_aspect_ratio=
1274                         av_div_q(
1275                          ff_mpeg2_aspect[s->aspect_ratio_info],
1276                          (AVRational){s->width, s->height}
1277                          );
1278                 }else{
1279                     s->avctx->sample_aspect_ratio=
1280                         av_div_q(
1281                          ff_mpeg2_aspect[s->aspect_ratio_info],
1282                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1283                         );
1284                 }
1285             }else{
1286                 s->avctx->sample_aspect_ratio=
1287                     ff_mpeg2_aspect[s->aspect_ratio_info];
1288             }
1289         }//MPEG-2
1290
1291         if(avctx->xvmc_acceleration){
1292             avctx->pix_fmt = avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1293         }else{
1294             if(s->chroma_format <  2){
1295                 avctx->pix_fmt = PIX_FMT_YUV420P;
1296             }else
1297             if(s->chroma_format == 2){
1298                 avctx->pix_fmt = PIX_FMT_YUV422P;
1299             }else
1300             if(s->chroma_format >  2){
1301                 avctx->pix_fmt = PIX_FMT_YUV444P;
1302             }
1303         }
1304         //until then pix_fmt may be changed right after codec init
1305         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT )
1306             if( avctx->idct_algo == FF_IDCT_AUTO )
1307                 avctx->idct_algo = FF_IDCT_SIMPLE;
1308
1309         /* Quantization matrices may need reordering
1310          * if DCT permutation is changed. */
1311         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1312
1313         if (MPV_common_init(s) < 0)
1314             return -2;
1315
1316         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1317         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1318         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1319         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1320
1321         s1->mpeg_enc_ctx_allocated = 1;
1322     }
1323     return 0;
1324 }
1325
1326 static int mpeg1_decode_picture(AVCodecContext *avctx,
1327                                 const uint8_t *buf, int buf_size)
1328 {
1329     Mpeg1Context *s1 = avctx->priv_data;
1330     MpegEncContext *s = &s1->mpeg_enc_ctx;
1331     int ref, f_code, vbv_delay;
1332
1333     if(mpeg_decode_postinit(s->avctx) < 0)
1334        return -2;
1335
1336     init_get_bits(&s->gb, buf, buf_size*8);
1337
1338     ref = get_bits(&s->gb, 10); /* temporal ref */
1339     s->pict_type = get_bits(&s->gb, 3);
1340     if(s->pict_type == 0 || s->pict_type > 3)
1341         return -1;
1342
1343     vbv_delay= get_bits(&s->gb, 16);
1344     if (s->pict_type == FF_P_TYPE || s->pict_type == FF_B_TYPE) {
1345         s->full_pel[0] = get_bits1(&s->gb);
1346         f_code = get_bits(&s->gb, 3);
1347         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1348             return -1;
1349         s->mpeg_f_code[0][0] = f_code;
1350         s->mpeg_f_code[0][1] = f_code;
1351     }
1352     if (s->pict_type == FF_B_TYPE) {
1353         s->full_pel[1] = get_bits1(&s->gb);
1354         f_code = get_bits(&s->gb, 3);
1355         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1356             return -1;
1357         s->mpeg_f_code[1][0] = f_code;
1358         s->mpeg_f_code[1][1] = f_code;
1359     }
1360     s->current_picture.pict_type= s->pict_type;
1361     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1362
1363     if(avctx->debug & FF_DEBUG_PICT_INFO)
1364         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1365
1366     s->y_dc_scale = 8;
1367     s->c_dc_scale = 8;
1368     s->first_slice = 1;
1369     return 0;
1370 }
1371
1372 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1373 {
1374     MpegEncContext *s= &s1->mpeg_enc_ctx;
1375     int horiz_size_ext, vert_size_ext;
1376     int bit_rate_ext;
1377
1378     skip_bits(&s->gb, 1); /* profile and level esc*/
1379     s->avctx->profile= get_bits(&s->gb, 3);
1380     s->avctx->level= get_bits(&s->gb, 4);
1381     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1382     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1383     horiz_size_ext = get_bits(&s->gb, 2);
1384     vert_size_ext = get_bits(&s->gb, 2);
1385     s->width |= (horiz_size_ext << 12);
1386     s->height |= (vert_size_ext << 12);
1387     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1388     s->bit_rate += (bit_rate_ext << 18) * 400;
1389     skip_bits1(&s->gb); /* marker */
1390     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1391
1392     s->low_delay = get_bits1(&s->gb);
1393     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1394
1395     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1396     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1397
1398     dprintf(s->avctx, "sequence extension\n");
1399     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1400     s->avctx->sub_id = 2; /* indicates MPEG-2 found */
1401
1402     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1403         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1404                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1405
1406 }
1407
1408 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1409 {
1410     MpegEncContext *s= &s1->mpeg_enc_ctx;
1411     int color_description, w, h;
1412
1413     skip_bits(&s->gb, 3); /* video format */
1414     color_description= get_bits1(&s->gb);
1415     if(color_description){
1416         skip_bits(&s->gb, 8); /* color primaries */
1417         skip_bits(&s->gb, 8); /* transfer_characteristics */
1418         skip_bits(&s->gb, 8); /* matrix_coefficients */
1419     }
1420     w= get_bits(&s->gb, 14);
1421     skip_bits(&s->gb, 1); //marker
1422     h= get_bits(&s->gb, 14);
1423     skip_bits(&s->gb, 1); //marker
1424
1425     s1->pan_scan.width= 16*w;
1426     s1->pan_scan.height=16*h;
1427
1428     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1429         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1430 }
1431
1432 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1433 {
1434     MpegEncContext *s= &s1->mpeg_enc_ctx;
1435     int i,nofco;
1436
1437     nofco = 1;
1438     if(s->progressive_sequence){
1439         if(s->repeat_first_field){
1440             nofco++;
1441             if(s->top_field_first)
1442                 nofco++;
1443         }
1444     }else{
1445         if(s->picture_structure == PICT_FRAME){
1446             nofco++;
1447             if(s->repeat_first_field)
1448                 nofco++;
1449         }
1450     }
1451     for(i=0; i<nofco; i++){
1452         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1453         skip_bits(&s->gb, 1); //marker
1454         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1455         skip_bits(&s->gb, 1); //marker
1456     }
1457
1458     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1459         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1460             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1461             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1462             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1463         );
1464 }
1465
1466 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1467 {
1468     int i, v, j;
1469
1470     dprintf(s->avctx, "matrix extension\n");
1471
1472     if (get_bits1(&s->gb)) {
1473         for(i=0;i<64;i++) {
1474             v = get_bits(&s->gb, 8);
1475             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1476             s->intra_matrix[j] = v;
1477             s->chroma_intra_matrix[j] = v;
1478         }
1479     }
1480     if (get_bits1(&s->gb)) {
1481         for(i=0;i<64;i++) {
1482             v = get_bits(&s->gb, 8);
1483             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1484             s->inter_matrix[j] = v;
1485             s->chroma_inter_matrix[j] = v;
1486         }
1487     }
1488     if (get_bits1(&s->gb)) {
1489         for(i=0;i<64;i++) {
1490             v = get_bits(&s->gb, 8);
1491             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1492             s->chroma_intra_matrix[j] = v;
1493         }
1494     }
1495     if (get_bits1(&s->gb)) {
1496         for(i=0;i<64;i++) {
1497             v = get_bits(&s->gb, 8);
1498             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1499             s->chroma_inter_matrix[j] = v;
1500         }
1501     }
1502 }
1503
1504 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1505 {
1506     MpegEncContext *s= &s1->mpeg_enc_ctx;
1507
1508     s->full_pel[0] = s->full_pel[1] = 0;
1509     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1510     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1511     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1512     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1513     if(!s->pict_type && s1->mpeg_enc_ctx_allocated){
1514         av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
1515         if(s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1]==15){
1516             if(s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1517                 s->pict_type= FF_I_TYPE;
1518             else
1519                 s->pict_type= FF_P_TYPE;
1520         }else
1521             s->pict_type= FF_B_TYPE;
1522         s->current_picture.pict_type= s->pict_type;
1523         s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1524         s->first_slice= 1;
1525     }
1526     s->intra_dc_precision = get_bits(&s->gb, 2);
1527     s->picture_structure = get_bits(&s->gb, 2);
1528     s->top_field_first = get_bits1(&s->gb);
1529     s->frame_pred_frame_dct = get_bits1(&s->gb);
1530     s->concealment_motion_vectors = get_bits1(&s->gb);
1531     s->q_scale_type = get_bits1(&s->gb);
1532     s->intra_vlc_format = get_bits1(&s->gb);
1533     s->alternate_scan = get_bits1(&s->gb);
1534     s->repeat_first_field = get_bits1(&s->gb);
1535     s->chroma_420_type = get_bits1(&s->gb);
1536     s->progressive_frame = get_bits1(&s->gb);
1537
1538     if(s->picture_structure == PICT_FRAME){
1539         s->first_field=0;
1540         s->v_edge_pos= 16*s->mb_height;
1541     }else{
1542         s->first_field ^= 1;
1543         s->v_edge_pos=  8*s->mb_height;
1544         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1545     }
1546
1547     if(s->alternate_scan){
1548         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1549         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1550     }else{
1551         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1552         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1553     }
1554
1555     /* composite display not parsed */
1556     dprintf(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1557     dprintf(s->avctx, "picture_structure=%d\n", s->picture_structure);
1558     dprintf(s->avctx, "top field first=%d\n", s->top_field_first);
1559     dprintf(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1560     dprintf(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1561     dprintf(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1562     dprintf(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1563     dprintf(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1564     dprintf(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1565 }
1566
1567 static void mpeg_decode_extension(AVCodecContext *avctx,
1568                                   const uint8_t *buf, int buf_size)
1569 {
1570     Mpeg1Context *s1 = avctx->priv_data;
1571     MpegEncContext *s = &s1->mpeg_enc_ctx;
1572     int ext_type;
1573
1574     init_get_bits(&s->gb, buf, buf_size*8);
1575
1576     ext_type = get_bits(&s->gb, 4);
1577     switch(ext_type) {
1578     case 0x1:
1579         mpeg_decode_sequence_extension(s1);
1580         break;
1581     case 0x2:
1582         mpeg_decode_sequence_display_extension(s1);
1583         break;
1584     case 0x3:
1585         mpeg_decode_quant_matrix_extension(s);
1586         break;
1587     case 0x7:
1588         mpeg_decode_picture_display_extension(s1);
1589         break;
1590     case 0x8:
1591         mpeg_decode_picture_coding_extension(s1);
1592         break;
1593     }
1594 }
1595
1596 static void exchange_uv(MpegEncContext *s){
1597     short * tmp = s->pblocks[4];
1598     s->pblocks[4] = s->pblocks[5];
1599     s->pblocks[5] = tmp;
1600 }
1601
1602 static int mpeg_field_start(MpegEncContext *s){
1603     AVCodecContext *avctx= s->avctx;
1604     Mpeg1Context *s1 = (Mpeg1Context*)s;
1605
1606     /* start frame decoding */
1607     if(s->first_field || s->picture_structure==PICT_FRAME){
1608         if(MPV_frame_start(s, avctx) < 0)
1609             return -1;
1610
1611         ff_er_frame_start(s);
1612
1613         /* first check if we must repeat the frame */
1614         s->current_picture_ptr->repeat_pict = 0;
1615         if (s->repeat_first_field) {
1616             if (s->progressive_sequence) {
1617                 if (s->top_field_first)
1618                     s->current_picture_ptr->repeat_pict = 4;
1619                 else
1620                     s->current_picture_ptr->repeat_pict = 2;
1621             } else if (s->progressive_frame) {
1622                 s->current_picture_ptr->repeat_pict = 1;
1623             }
1624         }
1625
1626         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1627     }else{ //second field
1628             int i;
1629
1630             if(!s->current_picture_ptr){
1631                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1632                 return -1;
1633             }
1634
1635             for(i=0; i<4; i++){
1636                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1637                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1638                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1639                 }
1640             }
1641     }
1642 #ifdef HAVE_XVMC
1643 // MPV_frame_start will call this function too,
1644 // but we need to call it on every field
1645     if(s->avctx->xvmc_acceleration)
1646          XVMC_field_start(s,avctx);
1647 #endif
1648
1649     return 0;
1650 }
1651
1652 #define DECODE_SLICE_ERROR -1
1653 #define DECODE_SLICE_OK 0
1654
1655 /**
1656  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1657  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1658  *         DECODE_SLICE_OK if this slice is ok<br>
1659  */
1660 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1661                              const uint8_t **buf, int buf_size)
1662 {
1663     MpegEncContext *s = &s1->mpeg_enc_ctx;
1664     AVCodecContext *avctx= s->avctx;
1665     const int field_pic= s->picture_structure != PICT_FRAME;
1666     const int lowres= s->avctx->lowres;
1667
1668     s->resync_mb_x=
1669     s->resync_mb_y= -1;
1670
1671     if (mb_y<<field_pic >= s->mb_height){
1672         av_log(s->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s->mb_height);
1673         return -1;
1674     }
1675
1676     init_get_bits(&s->gb, *buf, buf_size*8);
1677
1678     ff_mpeg1_clean_buffers(s);
1679     s->interlaced_dct = 0;
1680
1681     s->qscale = get_qscale(s);
1682
1683     if(s->qscale == 0){
1684         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1685         return -1;
1686     }
1687
1688     /* extra slice info */
1689     while (get_bits1(&s->gb) != 0) {
1690         skip_bits(&s->gb, 8);
1691     }
1692
1693     s->mb_x=0;
1694
1695     for(;;) {
1696         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1697         if (code < 0){
1698             av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1699             return -1;
1700         }
1701         if (code >= 33) {
1702             if (code == 33) {
1703                 s->mb_x += 33;
1704             }
1705             /* otherwise, stuffing, nothing to do */
1706         } else {
1707             s->mb_x += code;
1708             break;
1709         }
1710     }
1711     if(s->mb_x >= (unsigned)s->mb_width){
1712         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1713         return -1;
1714     }
1715
1716     s->resync_mb_x= s->mb_x;
1717     s->resync_mb_y= s->mb_y= mb_y;
1718     s->mb_skip_run= 0;
1719     ff_init_block_index(s);
1720
1721     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1722         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1723              av_log(s->avctx, AV_LOG_DEBUG, "qp:%d fc:%2d%2d%2d%2d %s %s %s %s %s dc:%d pstruct:%d fdct:%d cmv:%d qtype:%d ivlc:%d rff:%d %s\n",
1724                  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],
1725                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
1726                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1727                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1728                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1729         }
1730     }
1731
1732     for(;;) {
1733 #ifdef HAVE_XVMC
1734         //If 1, we memcpy blocks in xvmcvideo.
1735         if(s->avctx->xvmc_acceleration > 1)
1736             XVMC_init_block(s);//set s->block
1737 #endif
1738
1739         if(mpeg_decode_mb(s, s->block) < 0)
1740             return -1;
1741
1742         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1743             const int wrap = field_pic ? 2*s->b8_stride : s->b8_stride;
1744             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1745             int motion_x, motion_y, dir, i;
1746             if(field_pic && !s->first_field)
1747                 xy += wrap/2;
1748
1749             for(i=0; i<2; i++){
1750                 for(dir=0; dir<2; dir++){
1751                     if (s->mb_intra || (dir==1 && s->pict_type != FF_B_TYPE)) {
1752                         motion_x = motion_y = 0;
1753                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1754                         motion_x = s->mv[dir][0][0];
1755                         motion_y = s->mv[dir][0][1];
1756                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1757                         motion_x = s->mv[dir][i][0];
1758                         motion_y = s->mv[dir][i][1];
1759                     }
1760
1761                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1762                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1763                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1764                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1765                     s->current_picture.ref_index [dir][xy    ]=
1766                     s->current_picture.ref_index [dir][xy + 1]= s->field_select[dir][i];
1767                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1768                 }
1769                 xy += wrap;
1770             }
1771         }
1772
1773         s->dest[0] += 16 >> lowres;
1774         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1775         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1776
1777         MPV_decode_mb(s, s->block);
1778
1779         if (++s->mb_x >= s->mb_width) {
1780             const int mb_size= 16>>s->avctx->lowres;
1781
1782             ff_draw_horiz_band(s, mb_size*s->mb_y, mb_size);
1783
1784             s->mb_x = 0;
1785             s->mb_y++;
1786
1787             if(s->mb_y<<field_pic >= s->mb_height){
1788                 int left= s->gb.size_in_bits - get_bits_count(&s->gb);
1789                 int is_d10= s->chroma_format==2 && s->pict_type==FF_I_TYPE && avctx->profile==0 && avctx->level==5
1790                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1791                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1792
1793                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1794                    || (avctx->error_recognition >= FF_ER_AGGRESSIVE && left>8)){
1795                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1796                     return -1;
1797                 }else
1798                     goto eos;
1799             }
1800
1801             ff_init_block_index(s);
1802         }
1803
1804         /* skip mb handling */
1805         if (s->mb_skip_run == -1) {
1806             /* read increment again */
1807             s->mb_skip_run = 0;
1808             for(;;) {
1809                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1810                 if (code < 0){
1811                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1812                     return -1;
1813                 }
1814                 if (code >= 33) {
1815                     if (code == 33) {
1816                         s->mb_skip_run += 33;
1817                     }else if(code == 35){
1818                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1819                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1820                             return -1;
1821                         }
1822                         goto eos; /* end of slice */
1823                     }
1824                     /* otherwise, stuffing, nothing to do */
1825                 } else {
1826                     s->mb_skip_run += code;
1827                     break;
1828                 }
1829             }
1830             if(s->mb_skip_run){
1831                 int i;
1832                 if(s->pict_type == FF_I_TYPE){
1833                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1834                     return -1;
1835                 }
1836
1837                 /* skip mb */
1838                 s->mb_intra = 0;
1839                 for(i=0;i<12;i++)
1840                     s->block_last_index[i] = -1;
1841                 if(s->picture_structure == PICT_FRAME)
1842                     s->mv_type = MV_TYPE_16X16;
1843                 else
1844                     s->mv_type = MV_TYPE_FIELD;
1845                 if (s->pict_type == FF_P_TYPE) {
1846                     /* if P type, zero motion vector is implied */
1847                     s->mv_dir = MV_DIR_FORWARD;
1848                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1849                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1850                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1851                     s->field_select[0][0]= s->picture_structure - 1;
1852                 } else {
1853                     /* if B type, reuse previous vectors and directions */
1854                     s->mv[0][0][0] = s->last_mv[0][0][0];
1855                     s->mv[0][0][1] = s->last_mv[0][0][1];
1856                     s->mv[1][0][0] = s->last_mv[1][0][0];
1857                     s->mv[1][0][1] = s->last_mv[1][0][1];
1858                 }
1859             }
1860         }
1861     }
1862 eos: // end of slice
1863     *buf += (get_bits_count(&s->gb)-1)/8;
1864 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1865     return 0;
1866 }
1867
1868 static int slice_decode_thread(AVCodecContext *c, void *arg){
1869     MpegEncContext *s= *(void**)arg;
1870     const uint8_t *buf= s->gb.buffer;
1871     int mb_y= s->start_mb_y;
1872
1873     s->error_count= 3*(s->end_mb_y - s->start_mb_y)*s->mb_width;
1874
1875     for(;;){
1876         uint32_t start_code;
1877         int ret;
1878
1879         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1880         emms_c();
1881 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1882 //ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, s->start_mb_y, s->end_mb_y, s->error_count);
1883         if(ret < 0){
1884             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1885                 ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, AC_ERROR|DC_ERROR|MV_ERROR);
1886         }else{
1887             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
1888         }
1889
1890         if(s->mb_y == s->end_mb_y)
1891             return 0;
1892
1893         start_code= -1;
1894         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1895         mb_y= start_code - SLICE_MIN_START_CODE;
1896         if(mb_y < 0 || mb_y >= s->end_mb_y)
1897             return -1;
1898     }
1899
1900     return 0; //not reached
1901 }
1902
1903 /**
1904  * Handles slice ends.
1905  * @return 1 if it seems to be the last slice
1906  */
1907 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1908 {
1909     Mpeg1Context *s1 = avctx->priv_data;
1910     MpegEncContext *s = &s1->mpeg_enc_ctx;
1911
1912     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1913         return 0;
1914
1915 #ifdef HAVE_XVMC
1916     if(s->avctx->xvmc_acceleration)
1917         XVMC_field_end(s);
1918 #endif
1919     /* end of slice reached */
1920     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1921         /* end of image */
1922
1923         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1924
1925         ff_er_frame_end(s);
1926
1927         MPV_frame_end(s);
1928
1929         if (s->pict_type == FF_B_TYPE || s->low_delay) {
1930             *pict= *(AVFrame*)s->current_picture_ptr;
1931             ff_print_debug_info(s, pict);
1932         } else {
1933             s->picture_number++;
1934             /* latency of 1 frame for I- and P-frames */
1935             /* XXX: use another variable than picture_number */
1936             if (s->last_picture_ptr != NULL) {
1937                 *pict= *(AVFrame*)s->last_picture_ptr;
1938                  ff_print_debug_info(s, pict);
1939             }
1940         }
1941
1942         return 1;
1943     } else {
1944         return 0;
1945     }
1946 }
1947
1948 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1949                                  const uint8_t *buf, int buf_size)
1950 {
1951     Mpeg1Context *s1 = avctx->priv_data;
1952     MpegEncContext *s = &s1->mpeg_enc_ctx;
1953     int width,height;
1954     int i, v, j;
1955
1956     init_get_bits(&s->gb, buf, buf_size*8);
1957
1958     width = get_bits(&s->gb, 12);
1959     height = get_bits(&s->gb, 12);
1960     if (width <= 0 || height <= 0)
1961         return -1;
1962     s->aspect_ratio_info= get_bits(&s->gb, 4);
1963     if (s->aspect_ratio_info == 0) {
1964         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
1965         if (avctx->error_recognition >= FF_ER_COMPLIANT)
1966             return -1;
1967     }
1968     s->frame_rate_index = get_bits(&s->gb, 4);
1969     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
1970         return -1;
1971     s->bit_rate = get_bits(&s->gb, 18) * 400;
1972     if (get_bits1(&s->gb) == 0) /* marker */
1973         return -1;
1974     s->width = width;
1975     s->height = height;
1976
1977     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
1978     skip_bits(&s->gb, 1);
1979
1980     /* get matrix */
1981     if (get_bits1(&s->gb)) {
1982         for(i=0;i<64;i++) {
1983             v = get_bits(&s->gb, 8);
1984             if(v==0){
1985                 av_log(s->avctx, AV_LOG_ERROR, "intra matrix damaged\n");
1986                 return -1;
1987             }
1988             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1989             s->intra_matrix[j] = v;
1990             s->chroma_intra_matrix[j] = v;
1991         }
1992 #ifdef DEBUG
1993         dprintf(s->avctx, "intra matrix present\n");
1994         for(i=0;i<64;i++)
1995             dprintf(s->avctx, " %d", s->intra_matrix[s->dsp.idct_permutation[i]]);
1996         dprintf(s->avctx, "\n");
1997 #endif
1998     } else {
1999         for(i=0;i<64;i++) {
2000             j = s->dsp.idct_permutation[i];
2001             v = ff_mpeg1_default_intra_matrix[i];
2002             s->intra_matrix[j] = v;
2003             s->chroma_intra_matrix[j] = v;
2004         }
2005     }
2006     if (get_bits1(&s->gb)) {
2007         for(i=0;i<64;i++) {
2008             v = get_bits(&s->gb, 8);
2009             if(v==0){
2010                 av_log(s->avctx, AV_LOG_ERROR, "inter matrix damaged\n");
2011                 return -1;
2012             }
2013             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
2014             s->inter_matrix[j] = v;
2015             s->chroma_inter_matrix[j] = v;
2016         }
2017 #ifdef DEBUG
2018         dprintf(s->avctx, "non-intra matrix present\n");
2019         for(i=0;i<64;i++)
2020             dprintf(s->avctx, " %d", s->inter_matrix[s->dsp.idct_permutation[i]]);
2021         dprintf(s->avctx, "\n");
2022 #endif
2023     } else {
2024         for(i=0;i<64;i++) {
2025             int j= s->dsp.idct_permutation[i];
2026             v = ff_mpeg1_default_non_intra_matrix[i];
2027             s->inter_matrix[j] = v;
2028             s->chroma_inter_matrix[j] = v;
2029         }
2030     }
2031
2032     if(show_bits(&s->gb, 23) != 0){
2033         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2034         return -1;
2035     }
2036
2037     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
2038     s->progressive_sequence = 1;
2039     s->progressive_frame = 1;
2040     s->picture_structure = PICT_FRAME;
2041     s->frame_pred_frame_dct = 1;
2042     s->chroma_format = 1;
2043     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2044     avctx->sub_id = 1; /* indicates MPEG-1 */
2045     s->out_format = FMT_MPEG1;
2046     s->swap_uv = 0;//AFAIK VCR2 does not have SEQ_HEADER
2047     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2048
2049     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2050         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2051                s->avctx->rc_buffer_size, s->bit_rate);
2052
2053     return 0;
2054 }
2055
2056 static int vcr2_init_sequence(AVCodecContext *avctx)
2057 {
2058     Mpeg1Context *s1 = avctx->priv_data;
2059     MpegEncContext *s = &s1->mpeg_enc_ctx;
2060     int i, v;
2061
2062     /* start new MPEG-1 context decoding */
2063     s->out_format = FMT_MPEG1;
2064     if (s1->mpeg_enc_ctx_allocated) {
2065         MPV_common_end(s);
2066     }
2067     s->width  = avctx->coded_width;
2068     s->height = avctx->coded_height;
2069     avctx->has_b_frames= 0; //true?
2070     s->low_delay= 1;
2071
2072     if(avctx->xvmc_acceleration){
2073         avctx->pix_fmt = avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
2074     }else{
2075         avctx->pix_fmt = PIX_FMT_YUV420P;
2076     }
2077
2078     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT )
2079         if( avctx->idct_algo == FF_IDCT_AUTO )
2080             avctx->idct_algo = FF_IDCT_SIMPLE;
2081
2082     if (MPV_common_init(s) < 0)
2083         return -1;
2084     exchange_uv(s);//common init reset pblocks, so we swap them here
2085     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2086     s1->mpeg_enc_ctx_allocated = 1;
2087
2088     for(i=0;i<64;i++) {
2089         int j= s->dsp.idct_permutation[i];
2090         v = ff_mpeg1_default_intra_matrix[i];
2091         s->intra_matrix[j] = v;
2092         s->chroma_intra_matrix[j] = v;
2093
2094         v = ff_mpeg1_default_non_intra_matrix[i];
2095         s->inter_matrix[j] = v;
2096         s->chroma_inter_matrix[j] = v;
2097     }
2098
2099     s->progressive_sequence = 1;
2100     s->progressive_frame = 1;
2101     s->picture_structure = PICT_FRAME;
2102     s->frame_pred_frame_dct = 1;
2103     s->chroma_format = 1;
2104     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2105     avctx->sub_id = 2; /* indicates MPEG-2 */
2106     return 0;
2107 }
2108
2109
2110 static void mpeg_decode_user_data(AVCodecContext *avctx,
2111                                   const uint8_t *buf, int buf_size)
2112 {
2113     const uint8_t *p;
2114     int len, flags;
2115     p = buf;
2116     len = buf_size;
2117
2118     /* we parse the DTG active format information */
2119     if (len >= 5 &&
2120         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2121         flags = p[4];
2122         p += 5;
2123         len -= 5;
2124         if (flags & 0x80) {
2125             /* skip event id */
2126             if (len < 2)
2127                 return;
2128             p += 2;
2129             len -= 2;
2130         }
2131         if (flags & 0x40) {
2132             if (len < 1)
2133                 return;
2134             avctx->dtg_active_format = p[0] & 0x0f;
2135         }
2136     }
2137 }
2138
2139 static void mpeg_decode_gop(AVCodecContext *avctx,
2140                             const uint8_t *buf, int buf_size){
2141     Mpeg1Context *s1 = avctx->priv_data;
2142     MpegEncContext *s = &s1->mpeg_enc_ctx;
2143
2144     int drop_frame_flag;
2145     int time_code_hours, time_code_minutes;
2146     int time_code_seconds, time_code_pictures;
2147     int closed_gop, broken_link;
2148
2149     init_get_bits(&s->gb, buf, buf_size*8);
2150
2151     drop_frame_flag = get_bits1(&s->gb);
2152
2153     time_code_hours=get_bits(&s->gb,5);
2154     time_code_minutes = get_bits(&s->gb,6);
2155     skip_bits1(&s->gb);//marker bit
2156     time_code_seconds = get_bits(&s->gb,6);
2157     time_code_pictures = get_bits(&s->gb,6);
2158
2159     closed_gop  = get_bits1(&s->gb);
2160     /*broken_link indicate that after editing the
2161       reference frames of the first B-Frames after GOP I-Frame
2162       are missing (open gop)*/
2163     broken_link = get_bits1(&s->gb);
2164
2165     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2166         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2167             time_code_hours, time_code_minutes, time_code_seconds,
2168             time_code_pictures, closed_gop, broken_link);
2169 }
2170 /**
2171  * Finds the end of the current frame in the bitstream.
2172  * @return the position of the first byte of the next frame, or -1
2173  */
2174 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
2175 {
2176     int i;
2177     uint32_t state= pc->state;
2178
2179     /* EOF considered as end of frame */
2180     if (buf_size == 0)
2181         return 0;
2182
2183 /*
2184  0  frame start         -> 1/4
2185  1  first_SEQEXT        -> 0/2
2186  2  first field start   -> 3/0
2187  3  second_SEQEXT       -> 2/0
2188  4  searching end
2189 */
2190
2191     for(i=0; i<buf_size; i++){
2192         assert(pc->frame_start_found>=0 && pc->frame_start_found<=4);
2193         if(pc->frame_start_found&1){
2194             if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80)
2195                 pc->frame_start_found--;
2196             else if(state == EXT_START_CODE+2){
2197                 if((buf[i]&3) == 3) pc->frame_start_found= 0;
2198                 else                pc->frame_start_found= (pc->frame_start_found+1)&3;
2199             }
2200             state++;
2201         }else{
2202             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2203             if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2204                 i++;
2205                 pc->frame_start_found=4;
2206             }
2207             if(state == SEQ_END_CODE){
2208                 pc->state=-1;
2209                 return i+1;
2210             }
2211             if(pc->frame_start_found==2 && state == SEQ_START_CODE)
2212                 pc->frame_start_found= 0;
2213             if(pc->frame_start_found<4 && state == EXT_START_CODE)
2214                 pc->frame_start_found++;
2215             if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){
2216                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2217                     pc->frame_start_found=0;
2218                     pc->state=-1;
2219                     return i-3;
2220                 }
2221             }
2222         }
2223     }
2224     pc->state= state;
2225     return END_NOT_FOUND;
2226 }
2227
2228 static int decode_chunks(AVCodecContext *avctx,
2229                              AVFrame *picture, int *data_size,
2230                              const uint8_t *buf, int buf_size);
2231
2232 /* handle buffering and image synchronisation */
2233 static int mpeg_decode_frame(AVCodecContext *avctx,
2234                              void *data, int *data_size,
2235                              const uint8_t *buf, int buf_size)
2236 {
2237     Mpeg1Context *s = avctx->priv_data;
2238     AVFrame *picture = data;
2239     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2240     dprintf(avctx, "fill_buffer\n");
2241
2242     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2243         /* special case for last picture */
2244         if (s2->low_delay==0 && s2->next_picture_ptr) {
2245             *picture= *(AVFrame*)s2->next_picture_ptr;
2246             s2->next_picture_ptr= NULL;
2247
2248             *data_size = sizeof(AVFrame);
2249         }
2250         return buf_size;
2251     }
2252
2253     if(s2->flags&CODEC_FLAG_TRUNCATED){
2254         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size);
2255
2256         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2257             return buf_size;
2258     }
2259
2260 #if 0
2261     if (s->repeat_field % 2 == 1) {
2262         s->repeat_field++;
2263         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2264         //        s2->picture_number, s->repeat_field);
2265         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2266             *data_size = sizeof(AVPicture);
2267             goto the_end;
2268         }
2269     }
2270 #endif
2271
2272     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == ff_get_fourcc("VCR2"))
2273         vcr2_init_sequence(avctx);
2274
2275     s->slice_count= 0;
2276
2277     if(avctx->extradata && !avctx->frame_number)
2278         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
2279
2280     return decode_chunks(avctx, picture, data_size, buf, buf_size);
2281 }
2282
2283 static int decode_chunks(AVCodecContext *avctx,
2284                              AVFrame *picture, int *data_size,
2285                              const uint8_t *buf, int buf_size)
2286 {
2287     Mpeg1Context *s = avctx->priv_data;
2288     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2289     const uint8_t *buf_ptr = buf;
2290     const uint8_t *buf_end = buf + buf_size;
2291     int ret, input_size;
2292
2293     for(;;) {
2294         /* find next start code */
2295         uint32_t start_code = -1;
2296         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2297         if (start_code > 0x1ff){
2298             if(s2->pict_type != FF_B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2299                 if(avctx->thread_count > 1){
2300                     int i;
2301
2302                     avctx->execute(avctx, slice_decode_thread,  (void**)&(s2->thread_context[0]), NULL, s->slice_count, sizeof(void*));
2303                     for(i=0; i<s->slice_count; i++)
2304                         s2->error_count += s2->thread_context[i]->error_count;
2305                 }
2306                 if (slice_end(avctx, picture)) {
2307                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2308                         *data_size = sizeof(AVPicture);
2309                 }
2310             }
2311             s2->pict_type= 0;
2312             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2313         }
2314
2315         input_size = buf_end - buf_ptr;
2316
2317         if(avctx->debug & FF_DEBUG_STARTCODE){
2318             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2319         }
2320
2321         /* prepare data for next start code */
2322         switch(start_code) {
2323         case SEQ_START_CODE:
2324             mpeg1_decode_sequence(avctx, buf_ptr,
2325                                     input_size);
2326             break;
2327
2328         case PICTURE_START_CODE:
2329             /* we have a complete image: we try to decompress it */
2330             if(mpeg1_decode_picture(avctx,
2331                                     buf_ptr, input_size) < 0)
2332                 s2->pict_type=0;
2333             break;
2334         case EXT_START_CODE:
2335             mpeg_decode_extension(avctx,
2336                                     buf_ptr, input_size);
2337             break;
2338         case USER_START_CODE:
2339             mpeg_decode_user_data(avctx,
2340                                     buf_ptr, input_size);
2341             break;
2342         case GOP_START_CODE:
2343             s2->first_field=0;
2344             mpeg_decode_gop(avctx,
2345                                     buf_ptr, input_size);
2346             break;
2347         default:
2348             if (start_code >= SLICE_MIN_START_CODE &&
2349                 start_code <= SLICE_MAX_START_CODE) {
2350                 int mb_y= start_code - SLICE_MIN_START_CODE;
2351
2352                 if(s2->last_picture_ptr==NULL){
2353                 /* Skip B-frames if we do not have reference frames. */
2354                     if(s2->pict_type==FF_B_TYPE) break;
2355                 }
2356                 if(s2->next_picture_ptr==NULL){
2357                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2358                     if(s2->pict_type==FF_P_TYPE && (s2->first_field || s2->picture_structure==PICT_FRAME)) break;
2359                 }
2360                 /* Skip B-frames if we are in a hurry. */
2361                 if(avctx->hurry_up && s2->pict_type==FF_B_TYPE) break;
2362                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==FF_B_TYPE)
2363                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=FF_I_TYPE)
2364                     || avctx->skip_frame >= AVDISCARD_ALL)
2365                     break;
2366                 /* Skip everything if we are in a hurry>=5. */
2367                 if(avctx->hurry_up>=5) break;
2368
2369                 if (!s->mpeg_enc_ctx_allocated) break;
2370
2371                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2372                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2373                         break;
2374                 }
2375
2376                 if(!s2->pict_type){
2377                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2378                     break;
2379                 }
2380
2381                 if(s2->first_slice){
2382                     s2->first_slice=0;
2383                             if(mpeg_field_start(s2) < 0)
2384                         return -1;
2385                     }
2386                 if(!s2->current_picture_ptr){
2387                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2388                     return -1;
2389                 }
2390
2391                 if(avctx->thread_count > 1){
2392                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2393                     if(threshold <= mb_y){
2394                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2395
2396                         thread_context->start_mb_y= mb_y;
2397                         thread_context->end_mb_y  = s2->mb_height;
2398                         if(s->slice_count){
2399                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2400                             ff_update_duplicate_context(thread_context, s2);
2401                         }
2402                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2403                         s->slice_count++;
2404                     }
2405                     buf_ptr += 2; //FIXME add minimum number of bytes per slice
2406                 }else{
2407                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2408                     emms_c();
2409
2410                     if(ret < 0){
2411                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2412                             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);
2413                     }else{
2414                         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);
2415                     }
2416                 }
2417             }
2418             break;
2419         }
2420     }
2421 }
2422
2423 static int mpeg_decode_end(AVCodecContext *avctx)
2424 {
2425     Mpeg1Context *s = avctx->priv_data;
2426
2427     if (s->mpeg_enc_ctx_allocated)
2428         MPV_common_end(&s->mpeg_enc_ctx);
2429     return 0;
2430 }
2431
2432 AVCodec mpeg1video_decoder = {
2433     "mpeg1video",
2434     CODEC_TYPE_VIDEO,
2435     CODEC_ID_MPEG1VIDEO,
2436     sizeof(Mpeg1Context),
2437     mpeg_decode_init,
2438     NULL,
2439     mpeg_decode_end,
2440     mpeg_decode_frame,
2441     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2442     .flush= ff_mpeg_flush,
2443     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2444 };
2445
2446 AVCodec mpeg2video_decoder = {
2447     "mpeg2video",
2448     CODEC_TYPE_VIDEO,
2449     CODEC_ID_MPEG2VIDEO,
2450     sizeof(Mpeg1Context),
2451     mpeg_decode_init,
2452     NULL,
2453     mpeg_decode_end,
2454     mpeg_decode_frame,
2455     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2456     .flush= ff_mpeg_flush,
2457     .long_name= NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2458 };
2459
2460 //legacy decoder
2461 AVCodec mpegvideo_decoder = {
2462     "mpegvideo",
2463     CODEC_TYPE_VIDEO,
2464     CODEC_ID_MPEG2VIDEO,
2465     sizeof(Mpeg1Context),
2466     mpeg_decode_init,
2467     NULL,
2468     mpeg_decode_end,
2469     mpeg_decode_frame,
2470     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2471     .flush= ff_mpeg_flush,
2472     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2473 };
2474
2475 #ifdef HAVE_XVMC
2476 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx){
2477     Mpeg1Context *s;
2478
2479     if( avctx->thread_count > 1)
2480         return -1;
2481     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2482         return -1;
2483     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2484         dprintf(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2485     }
2486     mpeg_decode_init(avctx);
2487     s = avctx->priv_data;
2488
2489     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2490     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2491
2492     return 0;
2493 }
2494
2495 AVCodec mpeg_xvmc_decoder = {
2496     "mpegvideo_xvmc",
2497     CODEC_TYPE_VIDEO,
2498     CODEC_ID_MPEG2VIDEO_XVMC,
2499     sizeof(Mpeg1Context),
2500     mpeg_mc_decode_init,
2501     NULL,
2502     mpeg_decode_end,
2503     mpeg_decode_frame,
2504     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2505     .flush= ff_mpeg_flush,
2506     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video XvMC (X-Video Motion Compensation)"),
2507 };
2508
2509 #endif