81c7342cfe60fa9654c951a90a0961b4a4a2a953
[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 libavcodec/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 #include "vdpau_internal.h"
38 #include "xvmc_internal.h"
39
40 //#undef NDEBUG
41 //#include <assert.h>
42
43
44 #define MV_VLC_BITS 9
45 #define MBINCR_VLC_BITS 9
46 #define MB_PAT_VLC_BITS 9
47 #define MB_PTYPE_VLC_BITS 6
48 #define MB_BTYPE_VLC_BITS 6
49
50 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
51                               DCTELEM *block,
52                               int n);
53 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n);
54 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
55                                         DCTELEM *block,
56                                         int n);
57 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
58                                     DCTELEM *block,
59                                     int n);
60 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, DCTELEM *block, int n);
61 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
62 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
63 static void exchange_uv(MpegEncContext *s);
64
65 static const enum PixelFormat pixfmt_xvmc_mpg2_420[] = {
66                                            PIX_FMT_XVMC_MPEG2_IDCT,
67                                            PIX_FMT_XVMC_MPEG2_MC,
68                                            PIX_FMT_NONE};
69
70 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
71
72
73 #define INIT_2D_VLC_RL(rl, static_size)\
74 {\
75     static RL_VLC_ELEM rl_vlc_table[static_size];\
76     INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\
77              &rl.table_vlc[0][1], 4, 2,\
78              &rl.table_vlc[0][0], 4, 2, static_size);\
79 \
80     rl.rl_vlc[0]= rl_vlc_table;\
81     init_2d_vlc_rl(&rl);\
82 }
83
84 static void init_2d_vlc_rl(RLTable *rl)
85 {
86     int i;
87
88     for(i=0; i<rl->vlc.table_size; i++){
89         int code= rl->vlc.table[i][0];
90         int len = rl->vlc.table[i][1];
91         int level, run;
92
93         if(len==0){ // illegal code
94             run= 65;
95             level= MAX_LEVEL;
96         }else if(len<0){ //more bits needed
97             run= 0;
98             level= code;
99         }else{
100             if(code==rl->n){ //esc
101                 run= 65;
102                 level= 0;
103             }else if(code==rl->n+1){ //eob
104                 run= 0;
105                 level= 127;
106             }else{
107                 run=   rl->table_run  [code] + 1;
108                 level= rl->table_level[code];
109             }
110         }
111         rl->rl_vlc[0][i].len= len;
112         rl->rl_vlc[0][i].level= level;
113         rl->rl_vlc[0][i].run= run;
114     }
115 }
116
117 void ff_mpeg12_common_init(MpegEncContext *s)
118 {
119
120     s->y_dc_scale_table=
121     s->c_dc_scale_table= mpeg2_dc_scale_table[s->intra_dc_precision];
122
123 }
124
125 void ff_mpeg1_clean_buffers(MpegEncContext *s){
126     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
127     s->last_dc[1] = s->last_dc[0];
128     s->last_dc[2] = s->last_dc[0];
129     memset(s->last_mv, 0, sizeof(s->last_mv));
130 }
131
132
133 /******************************************/
134 /* decoding */
135
136 static VLC mv_vlc;
137 static VLC mbincr_vlc;
138 static VLC mb_ptype_vlc;
139 static VLC mb_btype_vlc;
140 static VLC mb_pat_vlc;
141
142 av_cold void ff_mpeg12_init_vlcs(void)
143 {
144     static int done = 0;
145
146     if (!done) {
147         done = 1;
148
149         INIT_VLC_STATIC(&dc_lum_vlc, DC_VLC_BITS, 12,
150                  ff_mpeg12_vlc_dc_lum_bits, 1, 1,
151                  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
152         INIT_VLC_STATIC(&dc_chroma_vlc,  DC_VLC_BITS, 12,
153                  ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
154                  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
155         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 17,
156                  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
157                  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
158         INIT_VLC_STATIC(&mbincr_vlc, MBINCR_VLC_BITS, 36,
159                  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
160                  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
161         INIT_VLC_STATIC(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
162                  &ff_mpeg12_mbPatTable[0][1], 2, 1,
163                  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
164
165         INIT_VLC_STATIC(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
166                  &table_mb_ptype[0][1], 2, 1,
167                  &table_mb_ptype[0][0], 2, 1, 64);
168         INIT_VLC_STATIC(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
169                  &table_mb_btype[0][1], 2, 1,
170                  &table_mb_btype[0][0], 2, 1, 64);
171         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
172         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
173
174         INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
175         INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
176     }
177 }
178
179 static inline int get_dmv(MpegEncContext *s)
180 {
181     if(get_bits1(&s->gb))
182         return 1 - (get_bits1(&s->gb) << 1);
183     else
184         return 0;
185 }
186
187 static inline int get_qscale(MpegEncContext *s)
188 {
189     int qscale = get_bits(&s->gb, 5);
190     if (s->q_scale_type) {
191         return non_linear_qscale[qscale];
192     } else {
193         return qscale << 1;
194     }
195 }
196
197 /* motion type (for MPEG-2) */
198 #define MT_FIELD 1
199 #define MT_FRAME 2
200 #define MT_16X8  2
201 #define MT_DMV   3
202
203 static int mpeg_decode_mb(MpegEncContext *s,
204                           DCTELEM block[12][64])
205 {
206     int i, j, k, cbp, val, mb_type, motion_type;
207     const int mb_block_count = 4 + (1<< s->chroma_format);
208
209     dprintf(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
210
211     assert(s->mb_skipped==0);
212
213     if (s->mb_skip_run-- != 0) {
214         if (s->pict_type == FF_P_TYPE) {
215             s->mb_skipped = 1;
216             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
217         } else {
218             int mb_type;
219
220             if(s->mb_x)
221                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
222             else
223                 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
224             if(IS_INTRA(mb_type))
225                 return -1;
226
227             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
228                 mb_type | MB_TYPE_SKIP;
229 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
230
231             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
232                 s->mb_skipped = 1;
233         }
234
235         return 0;
236     }
237
238     switch(s->pict_type) {
239     default:
240     case FF_I_TYPE:
241         if (get_bits1(&s->gb) == 0) {
242             if (get_bits1(&s->gb) == 0){
243                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
244                 return -1;
245             }
246             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
247         } else {
248             mb_type = MB_TYPE_INTRA;
249         }
250         break;
251     case FF_P_TYPE:
252         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
253         if (mb_type < 0){
254             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
255             return -1;
256         }
257         mb_type = ptype2mb_type[ mb_type ];
258         break;
259     case FF_B_TYPE:
260         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
261         if (mb_type < 0){
262             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
263             return -1;
264         }
265         mb_type = btype2mb_type[ mb_type ];
266         break;
267     }
268     dprintf(s->avctx, "mb_type=%x\n", mb_type);
269 //    motion_type = 0; /* avoid warning */
270     if (IS_INTRA(mb_type)) {
271         s->dsp.clear_blocks(s->block[0]);
272
273         if(!s->chroma_y_shift){
274             s->dsp.clear_blocks(s->block[6]);
275         }
276
277         /* compute DCT type */
278         if (s->picture_structure == PICT_FRAME && //FIXME add an interlaced_dct coded var?
279             !s->frame_pred_frame_dct) {
280             s->interlaced_dct = get_bits1(&s->gb);
281         }
282
283         if (IS_QUANT(mb_type))
284             s->qscale = get_qscale(s);
285
286         if (s->concealment_motion_vectors) {
287             /* just parse them */
288             if (s->picture_structure != PICT_FRAME)
289                 skip_bits1(&s->gb); /* field select */
290
291             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
292                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
293             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
294                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
295
296             skip_bits1(&s->gb); /* marker */
297         }else
298             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
299         s->mb_intra = 1;
300 #if CONFIG_MPEG_XVMC_DECODER
301         //if 1, we memcpy blocks in xvmcvideo
302         if(s->avctx->xvmc_acceleration > 1){
303             ff_xvmc_pack_pblocks(s,-1);//inter are always full blocks
304             if(s->swap_uv){
305                 exchange_uv(s);
306             }
307         }
308 #endif
309
310         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
311             if(s->flags2 & CODEC_FLAG2_FAST){
312                 for(i=0;i<6;i++) {
313                     mpeg2_fast_decode_block_intra(s, s->pblocks[i], i);
314                 }
315             }else{
316                 for(i=0;i<mb_block_count;i++) {
317                     if (mpeg2_decode_block_intra(s, s->pblocks[i], i) < 0)
318                         return -1;
319                 }
320             }
321         } else {
322             for(i=0;i<6;i++) {
323                 if (ff_mpeg1_decode_block_intra(s, s->pblocks[i], i) < 0)
324                     return -1;
325             }
326         }
327     } else {
328         if (mb_type & MB_TYPE_ZERO_MV){
329             assert(mb_type & MB_TYPE_CBP);
330
331             s->mv_dir = MV_DIR_FORWARD;
332             if(s->picture_structure == PICT_FRAME){
333                 if(!s->frame_pred_frame_dct)
334                     s->interlaced_dct = get_bits1(&s->gb);
335                 s->mv_type = MV_TYPE_16X16;
336             }else{
337                 s->mv_type = MV_TYPE_FIELD;
338                 mb_type |= MB_TYPE_INTERLACED;
339                 s->field_select[0][0]= s->picture_structure - 1;
340             }
341
342             if (IS_QUANT(mb_type))
343                 s->qscale = get_qscale(s);
344
345             s->last_mv[0][0][0] = 0;
346             s->last_mv[0][0][1] = 0;
347             s->last_mv[0][1][0] = 0;
348             s->last_mv[0][1][1] = 0;
349             s->mv[0][0][0] = 0;
350             s->mv[0][0][1] = 0;
351         }else{
352             assert(mb_type & MB_TYPE_L0L1);
353 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
354             /* get additional motion vector type */
355             if (s->frame_pred_frame_dct)
356                 motion_type = MT_FRAME;
357             else{
358                 motion_type = get_bits(&s->gb, 2);
359                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
360                     s->interlaced_dct = get_bits1(&s->gb);
361             }
362
363             if (IS_QUANT(mb_type))
364                 s->qscale = get_qscale(s);
365
366             /* motion vectors */
367             s->mv_dir= (mb_type>>13)&3;
368             dprintf(s->avctx, "motion_type=%d\n", motion_type);
369             switch(motion_type) {
370             case MT_FRAME: /* or MT_16X8 */
371                 if (s->picture_structure == PICT_FRAME) {
372                     mb_type |= MB_TYPE_16x16;
373                     s->mv_type = MV_TYPE_16X16;
374                     for(i=0;i<2;i++) {
375                         if (USES_LIST(mb_type, i)) {
376                             /* MT_FRAME */
377                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
378                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
379                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
380                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
381                             /* full_pel: only for MPEG-1 */
382                             if (s->full_pel[i]){
383                                 s->mv[i][0][0] <<= 1;
384                                 s->mv[i][0][1] <<= 1;
385                             }
386                         }
387                     }
388                 } else {
389                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
390                     s->mv_type = MV_TYPE_16X8;
391                     for(i=0;i<2;i++) {
392                         if (USES_LIST(mb_type, i)) {
393                             /* MT_16X8 */
394                             for(j=0;j<2;j++) {
395                                 s->field_select[i][j] = get_bits1(&s->gb);
396                                 for(k=0;k<2;k++) {
397                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
398                                                              s->last_mv[i][j][k]);
399                                     s->last_mv[i][j][k] = val;
400                                     s->mv[i][j][k] = val;
401                                 }
402                             }
403                         }
404                     }
405                 }
406                 break;
407             case MT_FIELD:
408                 s->mv_type = MV_TYPE_FIELD;
409                 if (s->picture_structure == PICT_FRAME) {
410                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
411                     for(i=0;i<2;i++) {
412                         if (USES_LIST(mb_type, i)) {
413                             for(j=0;j<2;j++) {
414                                 s->field_select[i][j] = get_bits1(&s->gb);
415                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
416                                                          s->last_mv[i][j][0]);
417                                 s->last_mv[i][j][0] = val;
418                                 s->mv[i][j][0] = val;
419                                 dprintf(s->avctx, "fmx=%d\n", val);
420                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
421                                                          s->last_mv[i][j][1] >> 1);
422                                 s->last_mv[i][j][1] = val << 1;
423                                 s->mv[i][j][1] = val;
424                                 dprintf(s->avctx, "fmy=%d\n", val);
425                             }
426                         }
427                     }
428                 } else {
429                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
430                     for(i=0;i<2;i++) {
431                         if (USES_LIST(mb_type, i)) {
432                             s->field_select[i][0] = get_bits1(&s->gb);
433                             for(k=0;k<2;k++) {
434                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
435                                                          s->last_mv[i][0][k]);
436                                 s->last_mv[i][0][k] = val;
437                                 s->last_mv[i][1][k] = val;
438                                 s->mv[i][0][k] = val;
439                             }
440                         }
441                     }
442                 }
443                 break;
444             case MT_DMV:
445                 s->mv_type = MV_TYPE_DMV;
446                 for(i=0;i<2;i++) {
447                     if (USES_LIST(mb_type, i)) {
448                         int dmx, dmy, mx, my, m;
449                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
450                                                 s->last_mv[i][0][0]);
451                         s->last_mv[i][0][0] = mx;
452                         s->last_mv[i][1][0] = mx;
453                         dmx = get_dmv(s);
454                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
455                                                 s->last_mv[i][0][1] >> 1);
456                         dmy = get_dmv(s);
457
458
459                         s->last_mv[i][0][1] = my<<1;
460                         s->last_mv[i][1][1] = my<<1;
461
462                         s->mv[i][0][0] = mx;
463                         s->mv[i][0][1] = my;
464                         s->mv[i][1][0] = mx;//not used
465                         s->mv[i][1][1] = my;//not used
466
467                         if (s->picture_structure == PICT_FRAME) {
468                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
469
470                             //m = 1 + 2 * s->top_field_first;
471                             m = s->top_field_first ? 1 : 3;
472
473                             /* top -> top pred */
474                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
475                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
476                             m = 4 - m;
477                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
478                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
479                         } else {
480                             mb_type |= MB_TYPE_16x16;
481
482                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
483                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
484                             if(s->picture_structure == PICT_TOP_FIELD)
485                                 s->mv[i][2][1]--;
486                             else
487                                 s->mv[i][2][1]++;
488                         }
489                     }
490                 }
491                 break;
492             default:
493                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
494                 return -1;
495             }
496         }
497
498         s->mb_intra = 0;
499         if (HAS_CBP(mb_type)) {
500             s->dsp.clear_blocks(s->block[0]);
501
502             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
503             if(mb_block_count > 6){
504                  cbp<<= mb_block_count-6;
505                  cbp |= get_bits(&s->gb, mb_block_count-6);
506                  s->dsp.clear_blocks(s->block[6]);
507             }
508             if (cbp <= 0){
509                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
510                 return -1;
511             }
512
513 #if CONFIG_MPEG_XVMC_DECODER
514             //if 1, we memcpy blocks in xvmcvideo
515             if(s->avctx->xvmc_acceleration > 1){
516                 ff_xvmc_pack_pblocks(s,cbp);
517                 if(s->swap_uv){
518                     exchange_uv(s);
519                 }
520             }
521 #endif
522
523             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
524                 if(s->flags2 & CODEC_FLAG2_FAST){
525                     for(i=0;i<6;i++) {
526                         if(cbp & 32) {
527                             mpeg2_fast_decode_block_non_intra(s, s->pblocks[i], i);
528                         } else {
529                             s->block_last_index[i] = -1;
530                         }
531                         cbp+=cbp;
532                     }
533                 }else{
534                     cbp<<= 12-mb_block_count;
535
536                     for(i=0;i<mb_block_count;i++) {
537                         if ( cbp & (1<<11) ) {
538                             if (mpeg2_decode_block_non_intra(s, s->pblocks[i], i) < 0)
539                                 return -1;
540                         } else {
541                             s->block_last_index[i] = -1;
542                         }
543                         cbp+=cbp;
544                     }
545                 }
546             } else {
547                 if(s->flags2 & CODEC_FLAG2_FAST){
548                     for(i=0;i<6;i++) {
549                         if (cbp & 32) {
550                             mpeg1_fast_decode_block_inter(s, s->pblocks[i], i);
551                         } else {
552                             s->block_last_index[i] = -1;
553                         }
554                         cbp+=cbp;
555                     }
556                 }else{
557                     for(i=0;i<6;i++) {
558                         if (cbp & 32) {
559                             if (mpeg1_decode_block_inter(s, s->pblocks[i], i) < 0)
560                                 return -1;
561                         } else {
562                             s->block_last_index[i] = -1;
563                         }
564                         cbp+=cbp;
565                     }
566                 }
567             }
568         }else{
569             for(i=0;i<12;i++)
570                 s->block_last_index[i] = -1;
571         }
572     }
573
574     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
575
576     return 0;
577 }
578
579 /* as H.263, but only 17 codes */
580 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
581 {
582     int code, sign, val, l, shift;
583
584     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
585     if (code == 0) {
586         return pred;
587     }
588     if (code < 0) {
589         return 0xffff;
590     }
591
592     sign = get_bits1(&s->gb);
593     shift = fcode - 1;
594     val = code;
595     if (shift) {
596         val = (val - 1) << shift;
597         val |= get_bits(&s->gb, shift);
598         val++;
599     }
600     if (sign)
601         val = -val;
602     val += pred;
603
604     /* modulo decoding */
605     l= INT_BIT - 5 - shift;
606     val = (val<<l)>>l;
607     return val;
608 }
609
610 inline int ff_mpeg1_decode_block_intra(MpegEncContext *s,
611                                DCTELEM *block,
612                                int n)
613 {
614     int level, dc, diff, i, j, run;
615     int component;
616     RLTable *rl = &ff_rl_mpeg1;
617     uint8_t * const scantable= s->intra_scantable.permutated;
618     const uint16_t *quant_matrix= s->intra_matrix;
619     const int qscale= s->qscale;
620
621     /* DC coefficient */
622     component = (n <= 3 ? 0 : n - 4 + 1);
623     diff = decode_dc(&s->gb, component);
624     if (diff >= 0xffff)
625         return -1;
626     dc = s->last_dc[component];
627     dc += diff;
628     s->last_dc[component] = dc;
629     block[0] = dc*quant_matrix[0];
630     dprintf(s->avctx, "dc=%d diff=%d\n", dc, diff);
631     i = 0;
632     {
633         OPEN_READER(re, &s->gb);
634         /* now quantify & encode AC coefficients */
635         for(;;) {
636             UPDATE_CACHE(re, &s->gb);
637             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
638
639             if(level == 127){
640                 break;
641             } else if(level != 0) {
642                 i += run;
643                 j = scantable[i];
644                 level= (level*qscale*quant_matrix[j])>>4;
645                 level= (level-1)|1;
646                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
647                 LAST_SKIP_BITS(re, &s->gb, 1);
648             } else {
649                 /* escape */
650                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
651                 UPDATE_CACHE(re, &s->gb);
652                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
653                 if (level == -128) {
654                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
655                 } else if (level == 0) {
656                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
657                 }
658                 i += run;
659                 j = scantable[i];
660                 if(level<0){
661                     level= -level;
662                     level= (level*qscale*quant_matrix[j])>>4;
663                     level= (level-1)|1;
664                     level= -level;
665                 }else{
666                     level= (level*qscale*quant_matrix[j])>>4;
667                     level= (level-1)|1;
668                 }
669             }
670             if (i > 63){
671                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
672                 return -1;
673             }
674
675             block[j] = level;
676         }
677         CLOSE_READER(re, &s->gb);
678     }
679     s->block_last_index[n] = i;
680    return 0;
681 }
682
683 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
684                                DCTELEM *block,
685                                int n)
686 {
687     int level, i, j, run;
688     RLTable *rl = &ff_rl_mpeg1;
689     uint8_t * const scantable= s->intra_scantable.permutated;
690     const uint16_t *quant_matrix= s->inter_matrix;
691     const int qscale= s->qscale;
692
693     {
694         OPEN_READER(re, &s->gb);
695         i = -1;
696         // special case for first coefficient, no need to add second VLC table
697         UPDATE_CACHE(re, &s->gb);
698         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
699             level= (3*qscale*quant_matrix[0])>>5;
700             level= (level-1)|1;
701             if(GET_CACHE(re, &s->gb)&0x40000000)
702                 level= -level;
703             block[0] = level;
704             i++;
705             SKIP_BITS(re, &s->gb, 2);
706             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
707                 goto end;
708         }
709 #if MIN_CACHE_BITS < 19
710         UPDATE_CACHE(re, &s->gb);
711 #endif
712         /* now quantify & encode AC coefficients */
713         for(;;) {
714             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
715
716             if(level != 0) {
717                 i += run;
718                 j = scantable[i];
719                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
720                 level= (level-1)|1;
721                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
722                 SKIP_BITS(re, &s->gb, 1);
723             } else {
724                 /* escape */
725                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
726                 UPDATE_CACHE(re, &s->gb);
727                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
728                 if (level == -128) {
729                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
730                 } else if (level == 0) {
731                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
732                 }
733                 i += run;
734                 j = scantable[i];
735                 if(level<0){
736                     level= -level;
737                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
738                     level= (level-1)|1;
739                     level= -level;
740                 }else{
741                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
742                     level= (level-1)|1;
743                 }
744             }
745             if (i > 63){
746                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
747                 return -1;
748             }
749
750             block[j] = level;
751 #if MIN_CACHE_BITS < 19
752             UPDATE_CACHE(re, &s->gb);
753 #endif
754             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
755                 break;
756 #if MIN_CACHE_BITS >= 19
757             UPDATE_CACHE(re, &s->gb);
758 #endif
759         }
760 end:
761         LAST_SKIP_BITS(re, &s->gb, 2);
762         CLOSE_READER(re, &s->gb);
763     }
764     s->block_last_index[n] = i;
765     return 0;
766 }
767
768 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
769 {
770     int level, i, j, run;
771     RLTable *rl = &ff_rl_mpeg1;
772     uint8_t * const scantable= s->intra_scantable.permutated;
773     const int qscale= s->qscale;
774
775     {
776         OPEN_READER(re, &s->gb);
777         i = -1;
778         // special case for first coefficient, no need to add second VLC table
779         UPDATE_CACHE(re, &s->gb);
780         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
781             level= (3*qscale)>>1;
782             level= (level-1)|1;
783             if(GET_CACHE(re, &s->gb)&0x40000000)
784                 level= -level;
785             block[0] = level;
786             i++;
787             SKIP_BITS(re, &s->gb, 2);
788             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
789                 goto end;
790         }
791 #if MIN_CACHE_BITS < 19
792         UPDATE_CACHE(re, &s->gb);
793 #endif
794
795         /* now quantify & encode AC coefficients */
796         for(;;) {
797             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
798
799             if(level != 0) {
800                 i += run;
801                 j = scantable[i];
802                 level= ((level*2+1)*qscale)>>1;
803                 level= (level-1)|1;
804                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
805                 SKIP_BITS(re, &s->gb, 1);
806             } else {
807                 /* escape */
808                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
809                 UPDATE_CACHE(re, &s->gb);
810                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
811                 if (level == -128) {
812                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
813                 } else if (level == 0) {
814                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
815                 }
816                 i += run;
817                 j = scantable[i];
818                 if(level<0){
819                     level= -level;
820                     level= ((level*2+1)*qscale)>>1;
821                     level= (level-1)|1;
822                     level= -level;
823                 }else{
824                     level= ((level*2+1)*qscale)>>1;
825                     level= (level-1)|1;
826                 }
827             }
828
829             block[j] = level;
830 #if MIN_CACHE_BITS < 19
831             UPDATE_CACHE(re, &s->gb);
832 #endif
833             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
834                 break;
835 #if MIN_CACHE_BITS >= 19
836             UPDATE_CACHE(re, &s->gb);
837 #endif
838         }
839 end:
840         LAST_SKIP_BITS(re, &s->gb, 2);
841         CLOSE_READER(re, &s->gb);
842     }
843     s->block_last_index[n] = i;
844     return 0;
845 }
846
847
848 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
849                                DCTELEM *block,
850                                int n)
851 {
852     int level, i, j, run;
853     RLTable *rl = &ff_rl_mpeg1;
854     uint8_t * const scantable= s->intra_scantable.permutated;
855     const uint16_t *quant_matrix;
856     const int qscale= s->qscale;
857     int mismatch;
858
859     mismatch = 1;
860
861     {
862         OPEN_READER(re, &s->gb);
863         i = -1;
864         if (n < 4)
865             quant_matrix = s->inter_matrix;
866         else
867             quant_matrix = s->chroma_inter_matrix;
868
869         // special case for first coefficient, no need to add second VLC table
870         UPDATE_CACHE(re, &s->gb);
871         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
872             level= (3*qscale*quant_matrix[0])>>5;
873             if(GET_CACHE(re, &s->gb)&0x40000000)
874                 level= -level;
875             block[0] = level;
876             mismatch ^= level;
877             i++;
878             SKIP_BITS(re, &s->gb, 2);
879             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
880                 goto end;
881         }
882 #if MIN_CACHE_BITS < 19
883         UPDATE_CACHE(re, &s->gb);
884 #endif
885
886         /* now quantify & encode AC coefficients */
887         for(;;) {
888             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
889
890             if(level != 0) {
891                 i += run;
892                 j = scantable[i];
893                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
894                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
895                 SKIP_BITS(re, &s->gb, 1);
896             } else {
897                 /* escape */
898                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
899                 UPDATE_CACHE(re, &s->gb);
900                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
901
902                 i += run;
903                 j = scantable[i];
904                 if(level<0){
905                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
906                     level= -level;
907                 }else{
908                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
909                 }
910             }
911             if (i > 63){
912                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
913                 return -1;
914             }
915
916             mismatch ^= level;
917             block[j] = level;
918 #if MIN_CACHE_BITS < 19
919             UPDATE_CACHE(re, &s->gb);
920 #endif
921             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
922                 break;
923 #if MIN_CACHE_BITS >= 19
924             UPDATE_CACHE(re, &s->gb);
925 #endif
926         }
927 end:
928         LAST_SKIP_BITS(re, &s->gb, 2);
929         CLOSE_READER(re, &s->gb);
930     }
931     block[63] ^= (mismatch & 1);
932
933     s->block_last_index[n] = i;
934     return 0;
935 }
936
937 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
938                                DCTELEM *block,
939                                int n)
940 {
941     int level, i, j, run;
942     RLTable *rl = &ff_rl_mpeg1;
943     uint8_t * const scantable= s->intra_scantable.permutated;
944     const int qscale= s->qscale;
945     OPEN_READER(re, &s->gb);
946     i = -1;
947
948     // special case for first coefficient, no need to add second VLC table
949     UPDATE_CACHE(re, &s->gb);
950     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
951         level= (3*qscale)>>1;
952         if(GET_CACHE(re, &s->gb)&0x40000000)
953             level= -level;
954         block[0] = level;
955         i++;
956         SKIP_BITS(re, &s->gb, 2);
957         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
958             goto end;
959     }
960 #if MIN_CACHE_BITS < 19
961     UPDATE_CACHE(re, &s->gb);
962 #endif
963
964     /* now quantify & encode AC coefficients */
965     for(;;) {
966         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
967
968         if(level != 0) {
969             i += run;
970             j = scantable[i];
971             level= ((level*2+1)*qscale)>>1;
972             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
973             SKIP_BITS(re, &s->gb, 1);
974         } else {
975             /* escape */
976             run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
977             UPDATE_CACHE(re, &s->gb);
978             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
979
980             i += run;
981             j = scantable[i];
982             if(level<0){
983                 level= ((-level*2+1)*qscale)>>1;
984                 level= -level;
985             }else{
986                 level= ((level*2+1)*qscale)>>1;
987             }
988         }
989
990         block[j] = level;
991 #if MIN_CACHE_BITS < 19
992         UPDATE_CACHE(re, &s->gb);
993 #endif
994         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
995             break;
996 #if MIN_CACHE_BITS >=19
997         UPDATE_CACHE(re, &s->gb);
998 #endif
999     }
1000 end:
1001     LAST_SKIP_BITS(re, &s->gb, 2);
1002     CLOSE_READER(re, &s->gb);
1003     s->block_last_index[n] = i;
1004     return 0;
1005 }
1006
1007
1008 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1009                                DCTELEM *block,
1010                                int n)
1011 {
1012     int level, dc, diff, i, j, run;
1013     int component;
1014     RLTable *rl;
1015     uint8_t * const scantable= s->intra_scantable.permutated;
1016     const uint16_t *quant_matrix;
1017     const int qscale= s->qscale;
1018     int mismatch;
1019
1020     /* DC coefficient */
1021     if (n < 4){
1022         quant_matrix = s->intra_matrix;
1023         component = 0;
1024     }else{
1025         quant_matrix = s->chroma_intra_matrix;
1026         component = (n&1) + 1;
1027     }
1028     diff = decode_dc(&s->gb, component);
1029     if (diff >= 0xffff)
1030         return -1;
1031     dc = s->last_dc[component];
1032     dc += diff;
1033     s->last_dc[component] = dc;
1034     block[0] = dc << (3 - s->intra_dc_precision);
1035     dprintf(s->avctx, "dc=%d\n", block[0]);
1036     mismatch = block[0] ^ 1;
1037     i = 0;
1038     if (s->intra_vlc_format)
1039         rl = &ff_rl_mpeg2;
1040     else
1041         rl = &ff_rl_mpeg1;
1042
1043     {
1044         OPEN_READER(re, &s->gb);
1045         /* now quantify & encode AC coefficients */
1046         for(;;) {
1047             UPDATE_CACHE(re, &s->gb);
1048             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1049
1050             if(level == 127){
1051                 break;
1052             } else if(level != 0) {
1053                 i += run;
1054                 j = scantable[i];
1055                 level= (level*qscale*quant_matrix[j])>>4;
1056                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1057                 LAST_SKIP_BITS(re, &s->gb, 1);
1058             } else {
1059                 /* escape */
1060                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1061                 UPDATE_CACHE(re, &s->gb);
1062                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1063                 i += run;
1064                 j = scantable[i];
1065                 if(level<0){
1066                     level= (-level*qscale*quant_matrix[j])>>4;
1067                     level= -level;
1068                 }else{
1069                     level= (level*qscale*quant_matrix[j])>>4;
1070                 }
1071             }
1072             if (i > 63){
1073                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1074                 return -1;
1075             }
1076
1077             mismatch^= level;
1078             block[j] = level;
1079         }
1080         CLOSE_READER(re, &s->gb);
1081     }
1082     block[63]^= mismatch&1;
1083
1084     s->block_last_index[n] = i;
1085     return 0;
1086 }
1087
1088 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
1089                                DCTELEM *block,
1090                                int n)
1091 {
1092     int level, dc, diff, j, run;
1093     int component;
1094     RLTable *rl;
1095     uint8_t * scantable= s->intra_scantable.permutated;
1096     const uint16_t *quant_matrix;
1097     const int qscale= s->qscale;
1098
1099     /* DC coefficient */
1100     if (n < 4){
1101         quant_matrix = s->intra_matrix;
1102         component = 0;
1103     }else{
1104         quant_matrix = s->chroma_intra_matrix;
1105         component = (n&1) + 1;
1106     }
1107     diff = decode_dc(&s->gb, component);
1108     if (diff >= 0xffff)
1109         return -1;
1110     dc = s->last_dc[component];
1111     dc += diff;
1112     s->last_dc[component] = dc;
1113     block[0] = dc << (3 - s->intra_dc_precision);
1114     if (s->intra_vlc_format)
1115         rl = &ff_rl_mpeg2;
1116     else
1117         rl = &ff_rl_mpeg1;
1118
1119     {
1120         OPEN_READER(re, &s->gb);
1121         /* now quantify & encode AC coefficients */
1122         for(;;) {
1123             UPDATE_CACHE(re, &s->gb);
1124             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1125
1126             if(level == 127){
1127                 break;
1128             } else if(level != 0) {
1129                 scantable += run;
1130                 j = *scantable;
1131                 level= (level*qscale*quant_matrix[j])>>4;
1132                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1133                 LAST_SKIP_BITS(re, &s->gb, 1);
1134             } else {
1135                 /* escape */
1136                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1137                 UPDATE_CACHE(re, &s->gb);
1138                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1139                 scantable += run;
1140                 j = *scantable;
1141                 if(level<0){
1142                     level= (-level*qscale*quant_matrix[j])>>4;
1143                     level= -level;
1144                 }else{
1145                     level= (level*qscale*quant_matrix[j])>>4;
1146                 }
1147             }
1148
1149             block[j] = level;
1150         }
1151         CLOSE_READER(re, &s->gb);
1152     }
1153
1154     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
1155     return 0;
1156 }
1157
1158 typedef struct Mpeg1Context {
1159     MpegEncContext mpeg_enc_ctx;
1160     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1161     int repeat_field; /* true if we must repeat the field */
1162     AVPanScan pan_scan; /** some temporary storage for the panscan */
1163     int slice_count;
1164     int swap_uv;//indicate VCR2
1165     int save_aspect_info;
1166     int save_width, save_height;
1167     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1168
1169 } Mpeg1Context;
1170
1171 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1172 {
1173     Mpeg1Context *s = avctx->priv_data;
1174     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1175     int i;
1176
1177     /* we need some permutation to store matrices,
1178      * until MPV_common_init() sets the real permutation. */
1179     for(i=0;i<64;i++)
1180        s2->dsp.idct_permutation[i]=i;
1181
1182     MPV_decode_defaults(s2);
1183
1184     s->mpeg_enc_ctx.avctx= avctx;
1185     s->mpeg_enc_ctx.flags= avctx->flags;
1186     s->mpeg_enc_ctx.flags2= avctx->flags2;
1187     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1188     ff_mpeg12_init_vlcs();
1189
1190     s->mpeg_enc_ctx_allocated = 0;
1191     s->mpeg_enc_ctx.picture_number = 0;
1192     s->repeat_field = 0;
1193     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1194     return 0;
1195 }
1196
1197 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1198                                      const uint8_t *new_perm){
1199     uint16_t temp_matrix[64];
1200     int i;
1201
1202     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1203
1204     for(i=0;i<64;i++){
1205         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1206     }
1207 }
1208
1209 static enum PixelFormat mpeg_get_pixelformat(AVCodecContext *avctx){
1210     Mpeg1Context *s1 = avctx->priv_data;
1211     MpegEncContext *s = &s1->mpeg_enc_ctx;
1212
1213     if(avctx->xvmc_acceleration)
1214         return avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1215     else if(avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU){
1216         if(avctx->codec_id == CODEC_ID_MPEG1VIDEO)
1217             return PIX_FMT_VDPAU_MPEG1;
1218         else
1219             return PIX_FMT_VDPAU_MPEG2;
1220     }else{
1221         if(s->chroma_format <  2)
1222             return PIX_FMT_YUV420P;
1223         else if(s->chroma_format == 2)
1224             return PIX_FMT_YUV422P;
1225         else
1226             return PIX_FMT_YUV444P;
1227     }
1228 }
1229
1230 /* Call this function when we know all parameters.
1231  * It may be called in different places for MPEG-1 and MPEG-2. */
1232 static int mpeg_decode_postinit(AVCodecContext *avctx){
1233     Mpeg1Context *s1 = avctx->priv_data;
1234     MpegEncContext *s = &s1->mpeg_enc_ctx;
1235     uint8_t old_permutation[64];
1236
1237     if (
1238         (s1->mpeg_enc_ctx_allocated == 0)||
1239         avctx->coded_width  != s->width ||
1240         avctx->coded_height != s->height||
1241         s1->save_width != s->width ||
1242         s1->save_height != s->height ||
1243         s1->save_aspect_info != s->aspect_ratio_info||
1244         0)
1245     {
1246
1247         if (s1->mpeg_enc_ctx_allocated) {
1248             ParseContext pc= s->parse_context;
1249             s->parse_context.buffer=0;
1250             MPV_common_end(s);
1251             s->parse_context= pc;
1252         }
1253
1254         if( (s->width == 0 )||(s->height == 0))
1255             return -2;
1256
1257         avcodec_set_dimensions(avctx, s->width, s->height);
1258         avctx->bit_rate = s->bit_rate;
1259         s1->save_aspect_info = s->aspect_ratio_info;
1260         s1->save_width = s->width;
1261         s1->save_height = s->height;
1262
1263         /* low_delay may be forced, in this case we will have B-frames
1264          * that behave like P-frames. */
1265         avctx->has_b_frames = !(s->low_delay);
1266
1267         assert((avctx->sub_id==1) == (avctx->codec_id==CODEC_ID_MPEG1VIDEO));
1268         if(avctx->codec_id==CODEC_ID_MPEG1VIDEO){
1269             //MPEG-1 fps
1270             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1271             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1272             //MPEG-1 aspect
1273             avctx->sample_aspect_ratio= av_d2q(
1274                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1275
1276         }else{//MPEG-2
1277         //MPEG-2 fps
1278             av_reduce(
1279                 &s->avctx->time_base.den,
1280                 &s->avctx->time_base.num,
1281                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1282                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1283                 1<<30);
1284         //MPEG-2 aspect
1285             if(s->aspect_ratio_info > 1){
1286                 //we ignore the spec here as reality does not match the spec, see for example
1287                 // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
1288                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) || 1){
1289                     s->avctx->sample_aspect_ratio=
1290                         av_div_q(
1291                          ff_mpeg2_aspect[s->aspect_ratio_info],
1292                          (AVRational){s->width, s->height}
1293                          );
1294                 }else{
1295                     s->avctx->sample_aspect_ratio=
1296                         av_div_q(
1297                          ff_mpeg2_aspect[s->aspect_ratio_info],
1298                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1299                         );
1300                 }
1301             }else{
1302                 s->avctx->sample_aspect_ratio=
1303                     ff_mpeg2_aspect[s->aspect_ratio_info];
1304             }
1305         }//MPEG-2
1306
1307         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1308         //until then pix_fmt may be changed right after codec init
1309         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT ||
1310             s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
1311             if( avctx->idct_algo == FF_IDCT_AUTO )
1312                 avctx->idct_algo = FF_IDCT_SIMPLE;
1313
1314         /* Quantization matrices may need reordering
1315          * if DCT permutation is changed. */
1316         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1317
1318         if (MPV_common_init(s) < 0)
1319             return -2;
1320
1321         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1322         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1323         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1324         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1325
1326         s1->mpeg_enc_ctx_allocated = 1;
1327     }
1328     return 0;
1329 }
1330
1331 static int mpeg1_decode_picture(AVCodecContext *avctx,
1332                                 const uint8_t *buf, int buf_size)
1333 {
1334     Mpeg1Context *s1 = avctx->priv_data;
1335     MpegEncContext *s = &s1->mpeg_enc_ctx;
1336     int ref, f_code, vbv_delay;
1337
1338     if(mpeg_decode_postinit(s->avctx) < 0)
1339        return -2;
1340
1341     init_get_bits(&s->gb, buf, buf_size*8);
1342
1343     ref = get_bits(&s->gb, 10); /* temporal ref */
1344     s->pict_type = get_bits(&s->gb, 3);
1345     if(s->pict_type == 0 || s->pict_type > 3)
1346         return -1;
1347
1348     vbv_delay= get_bits(&s->gb, 16);
1349     if (s->pict_type == FF_P_TYPE || s->pict_type == FF_B_TYPE) {
1350         s->full_pel[0] = get_bits1(&s->gb);
1351         f_code = get_bits(&s->gb, 3);
1352         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1353             return -1;
1354         s->mpeg_f_code[0][0] = f_code;
1355         s->mpeg_f_code[0][1] = f_code;
1356     }
1357     if (s->pict_type == FF_B_TYPE) {
1358         s->full_pel[1] = get_bits1(&s->gb);
1359         f_code = get_bits(&s->gb, 3);
1360         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1361             return -1;
1362         s->mpeg_f_code[1][0] = f_code;
1363         s->mpeg_f_code[1][1] = f_code;
1364     }
1365     s->current_picture.pict_type= s->pict_type;
1366     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1367
1368     if(avctx->debug & FF_DEBUG_PICT_INFO)
1369         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1370
1371     s->y_dc_scale = 8;
1372     s->c_dc_scale = 8;
1373     s->first_slice = 1;
1374     return 0;
1375 }
1376
1377 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1378 {
1379     MpegEncContext *s= &s1->mpeg_enc_ctx;
1380     int horiz_size_ext, vert_size_ext;
1381     int bit_rate_ext;
1382
1383     skip_bits(&s->gb, 1); /* profile and level esc*/
1384     s->avctx->profile= get_bits(&s->gb, 3);
1385     s->avctx->level= get_bits(&s->gb, 4);
1386     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1387     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1388     horiz_size_ext = get_bits(&s->gb, 2);
1389     vert_size_ext = get_bits(&s->gb, 2);
1390     s->width |= (horiz_size_ext << 12);
1391     s->height |= (vert_size_ext << 12);
1392     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1393     s->bit_rate += (bit_rate_ext << 18) * 400;
1394     skip_bits1(&s->gb); /* marker */
1395     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1396
1397     s->low_delay = get_bits1(&s->gb);
1398     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1399
1400     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1401     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1402
1403     dprintf(s->avctx, "sequence extension\n");
1404     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1405     s->avctx->sub_id = 2; /* indicates MPEG-2 found */
1406
1407     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1408         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1409                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1410
1411 }
1412
1413 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1414 {
1415     MpegEncContext *s= &s1->mpeg_enc_ctx;
1416     int color_description, w, h;
1417
1418     skip_bits(&s->gb, 3); /* video format */
1419     color_description= get_bits1(&s->gb);
1420     if(color_description){
1421         skip_bits(&s->gb, 8); /* color primaries */
1422         skip_bits(&s->gb, 8); /* transfer_characteristics */
1423         skip_bits(&s->gb, 8); /* matrix_coefficients */
1424     }
1425     w= get_bits(&s->gb, 14);
1426     skip_bits(&s->gb, 1); //marker
1427     h= get_bits(&s->gb, 14);
1428     skip_bits(&s->gb, 1); //marker
1429
1430     s1->pan_scan.width= 16*w;
1431     s1->pan_scan.height=16*h;
1432
1433     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1434         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1435 }
1436
1437 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1438 {
1439     MpegEncContext *s= &s1->mpeg_enc_ctx;
1440     int i,nofco;
1441
1442     nofco = 1;
1443     if(s->progressive_sequence){
1444         if(s->repeat_first_field){
1445             nofco++;
1446             if(s->top_field_first)
1447                 nofco++;
1448         }
1449     }else{
1450         if(s->picture_structure == PICT_FRAME){
1451             nofco++;
1452             if(s->repeat_first_field)
1453                 nofco++;
1454         }
1455     }
1456     for(i=0; i<nofco; i++){
1457         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1458         skip_bits(&s->gb, 1); //marker
1459         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1460         skip_bits(&s->gb, 1); //marker
1461     }
1462
1463     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1464         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1465             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1466             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1467             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1468         );
1469 }
1470
1471 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1472 {
1473     int i, v, j;
1474
1475     dprintf(s->avctx, "matrix extension\n");
1476
1477     if (get_bits1(&s->gb)) {
1478         for(i=0;i<64;i++) {
1479             v = get_bits(&s->gb, 8);
1480             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1481             s->intra_matrix[j] = v;
1482             s->chroma_intra_matrix[j] = v;
1483         }
1484     }
1485     if (get_bits1(&s->gb)) {
1486         for(i=0;i<64;i++) {
1487             v = get_bits(&s->gb, 8);
1488             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1489             s->inter_matrix[j] = v;
1490             s->chroma_inter_matrix[j] = v;
1491         }
1492     }
1493     if (get_bits1(&s->gb)) {
1494         for(i=0;i<64;i++) {
1495             v = get_bits(&s->gb, 8);
1496             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1497             s->chroma_intra_matrix[j] = v;
1498         }
1499     }
1500     if (get_bits1(&s->gb)) {
1501         for(i=0;i<64;i++) {
1502             v = get_bits(&s->gb, 8);
1503             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1504             s->chroma_inter_matrix[j] = v;
1505         }
1506     }
1507 }
1508
1509 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1510 {
1511     MpegEncContext *s= &s1->mpeg_enc_ctx;
1512
1513     s->full_pel[0] = s->full_pel[1] = 0;
1514     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1515     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1516     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1517     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1518     if(!s->pict_type && s1->mpeg_enc_ctx_allocated){
1519         av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
1520         if(s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1]==15){
1521             if(s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1522                 s->pict_type= FF_I_TYPE;
1523             else
1524                 s->pict_type= FF_P_TYPE;
1525         }else
1526             s->pict_type= FF_B_TYPE;
1527         s->current_picture.pict_type= s->pict_type;
1528         s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1529         s->first_slice= 1;
1530     }
1531     s->intra_dc_precision = get_bits(&s->gb, 2);
1532     s->picture_structure = get_bits(&s->gb, 2);
1533     s->top_field_first = get_bits1(&s->gb);
1534     s->frame_pred_frame_dct = get_bits1(&s->gb);
1535     s->concealment_motion_vectors = get_bits1(&s->gb);
1536     s->q_scale_type = get_bits1(&s->gb);
1537     s->intra_vlc_format = get_bits1(&s->gb);
1538     s->alternate_scan = get_bits1(&s->gb);
1539     s->repeat_first_field = get_bits1(&s->gb);
1540     s->chroma_420_type = get_bits1(&s->gb);
1541     s->progressive_frame = get_bits1(&s->gb);
1542
1543     if(s->picture_structure == PICT_FRAME){
1544         s->first_field=0;
1545         s->v_edge_pos= 16*s->mb_height;
1546     }else{
1547         s->first_field ^= 1;
1548         s->v_edge_pos=  8*s->mb_height;
1549         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1550     }
1551
1552     if(s->alternate_scan){
1553         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1554         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1555     }else{
1556         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1557         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1558     }
1559
1560     /* composite display not parsed */
1561     dprintf(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1562     dprintf(s->avctx, "picture_structure=%d\n", s->picture_structure);
1563     dprintf(s->avctx, "top field first=%d\n", s->top_field_first);
1564     dprintf(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1565     dprintf(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1566     dprintf(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1567     dprintf(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1568     dprintf(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1569     dprintf(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1570 }
1571
1572 static void mpeg_decode_extension(AVCodecContext *avctx,
1573                                   const uint8_t *buf, int buf_size)
1574 {
1575     Mpeg1Context *s1 = avctx->priv_data;
1576     MpegEncContext *s = &s1->mpeg_enc_ctx;
1577     int ext_type;
1578
1579     init_get_bits(&s->gb, buf, buf_size*8);
1580
1581     ext_type = get_bits(&s->gb, 4);
1582     switch(ext_type) {
1583     case 0x1:
1584         mpeg_decode_sequence_extension(s1);
1585         break;
1586     case 0x2:
1587         mpeg_decode_sequence_display_extension(s1);
1588         break;
1589     case 0x3:
1590         mpeg_decode_quant_matrix_extension(s);
1591         break;
1592     case 0x7:
1593         mpeg_decode_picture_display_extension(s1);
1594         break;
1595     case 0x8:
1596         mpeg_decode_picture_coding_extension(s1);
1597         break;
1598     }
1599 }
1600
1601 static void exchange_uv(MpegEncContext *s){
1602     short * tmp = s->pblocks[4];
1603     s->pblocks[4] = s->pblocks[5];
1604     s->pblocks[5] = tmp;
1605 }
1606
1607 static int mpeg_field_start(MpegEncContext *s){
1608     AVCodecContext *avctx= s->avctx;
1609     Mpeg1Context *s1 = (Mpeg1Context*)s;
1610
1611     /* start frame decoding */
1612     if(s->first_field || s->picture_structure==PICT_FRAME){
1613         if(MPV_frame_start(s, avctx) < 0)
1614             return -1;
1615
1616         ff_er_frame_start(s);
1617
1618         /* first check if we must repeat the frame */
1619         s->current_picture_ptr->repeat_pict = 0;
1620         if (s->repeat_first_field) {
1621             if (s->progressive_sequence) {
1622                 if (s->top_field_first)
1623                     s->current_picture_ptr->repeat_pict = 4;
1624                 else
1625                     s->current_picture_ptr->repeat_pict = 2;
1626             } else if (s->progressive_frame) {
1627                 s->current_picture_ptr->repeat_pict = 1;
1628             }
1629         }
1630
1631         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1632     }else{ //second field
1633             int i;
1634
1635             if(!s->current_picture_ptr){
1636                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1637                 return -1;
1638             }
1639
1640             for(i=0; i<4; i++){
1641                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1642                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1643                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1644                 }
1645             }
1646     }
1647 #if CONFIG_MPEG_XVMC_DECODER
1648 // MPV_frame_start will call this function too,
1649 // but we need to call it on every field
1650     if(s->avctx->xvmc_acceleration)
1651          ff_xvmc_field_start(s,avctx);
1652 #endif
1653
1654     return 0;
1655 }
1656
1657 #define DECODE_SLICE_ERROR -1
1658 #define DECODE_SLICE_OK 0
1659
1660 /**
1661  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1662  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1663  *         DECODE_SLICE_OK if this slice is ok<br>
1664  */
1665 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1666                              const uint8_t **buf, int buf_size)
1667 {
1668     MpegEncContext *s = &s1->mpeg_enc_ctx;
1669     AVCodecContext *avctx= s->avctx;
1670     const int field_pic= s->picture_structure != PICT_FRAME;
1671     const int lowres= s->avctx->lowres;
1672
1673     s->resync_mb_x=
1674     s->resync_mb_y= -1;
1675
1676     if (mb_y<<field_pic >= s->mb_height){
1677         av_log(s->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s->mb_height);
1678         return -1;
1679     }
1680
1681     init_get_bits(&s->gb, *buf, buf_size*8);
1682
1683     ff_mpeg1_clean_buffers(s);
1684     s->interlaced_dct = 0;
1685
1686     s->qscale = get_qscale(s);
1687
1688     if(s->qscale == 0){
1689         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1690         return -1;
1691     }
1692
1693     /* extra slice info */
1694     while (get_bits1(&s->gb) != 0) {
1695         skip_bits(&s->gb, 8);
1696     }
1697
1698     s->mb_x=0;
1699
1700     for(;;) {
1701         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1702         if (code < 0){
1703             av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1704             return -1;
1705         }
1706         if (code >= 33) {
1707             if (code == 33) {
1708                 s->mb_x += 33;
1709             }
1710             /* otherwise, stuffing, nothing to do */
1711         } else {
1712             s->mb_x += code;
1713             break;
1714         }
1715     }
1716     if(s->mb_x >= (unsigned)s->mb_width){
1717         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1718         return -1;
1719     }
1720
1721     s->resync_mb_x= s->mb_x;
1722     s->resync_mb_y= s->mb_y= mb_y;
1723     s->mb_skip_run= 0;
1724     ff_init_block_index(s);
1725
1726     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1727         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1728              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",
1729                  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],
1730                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
1731                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1732                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1733                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1734         }
1735     }
1736
1737     for(;;) {
1738 #if CONFIG_MPEG_XVMC_DECODER
1739         //If 1, we memcpy blocks in xvmcvideo.
1740         if(s->avctx->xvmc_acceleration > 1)
1741             ff_xvmc_init_block(s);//set s->block
1742 #endif
1743
1744         if(mpeg_decode_mb(s, s->block) < 0)
1745             return -1;
1746
1747         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1748             const int wrap = field_pic ? 2*s->b8_stride : s->b8_stride;
1749             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1750             int motion_x, motion_y, dir, i;
1751             if(field_pic && !s->first_field)
1752                 xy += wrap/2;
1753
1754             for(i=0; i<2; i++){
1755                 for(dir=0; dir<2; dir++){
1756                     if (s->mb_intra || (dir==1 && s->pict_type != FF_B_TYPE)) {
1757                         motion_x = motion_y = 0;
1758                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1759                         motion_x = s->mv[dir][0][0];
1760                         motion_y = s->mv[dir][0][1];
1761                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1762                         motion_x = s->mv[dir][i][0];
1763                         motion_y = s->mv[dir][i][1];
1764                     }
1765
1766                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1767                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1768                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1769                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1770                     s->current_picture.ref_index [dir][xy    ]=
1771                     s->current_picture.ref_index [dir][xy + 1]= s->field_select[dir][i];
1772                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1773                 }
1774                 xy += wrap;
1775             }
1776         }
1777
1778         s->dest[0] += 16 >> lowres;
1779         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1780         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1781
1782         MPV_decode_mb(s, s->block);
1783
1784         if (++s->mb_x >= s->mb_width) {
1785             const int mb_size= 16>>s->avctx->lowres;
1786
1787             ff_draw_horiz_band(s, mb_size*s->mb_y, mb_size);
1788
1789             s->mb_x = 0;
1790             s->mb_y++;
1791
1792             if(s->mb_y<<field_pic >= s->mb_height){
1793                 int left= s->gb.size_in_bits - get_bits_count(&s->gb);
1794                 int is_d10= s->chroma_format==2 && s->pict_type==FF_I_TYPE && avctx->profile==0 && avctx->level==5
1795                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1796                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1797
1798                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1799                    || (avctx->error_recognition >= FF_ER_AGGRESSIVE && left>8)){
1800                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1801                     return -1;
1802                 }else
1803                     goto eos;
1804             }
1805
1806             ff_init_block_index(s);
1807         }
1808
1809         /* skip mb handling */
1810         if (s->mb_skip_run == -1) {
1811             /* read increment again */
1812             s->mb_skip_run = 0;
1813             for(;;) {
1814                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1815                 if (code < 0){
1816                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1817                     return -1;
1818                 }
1819                 if (code >= 33) {
1820                     if (code == 33) {
1821                         s->mb_skip_run += 33;
1822                     }else if(code == 35){
1823                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1824                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1825                             return -1;
1826                         }
1827                         goto eos; /* end of slice */
1828                     }
1829                     /* otherwise, stuffing, nothing to do */
1830                 } else {
1831                     s->mb_skip_run += code;
1832                     break;
1833                 }
1834             }
1835             if(s->mb_skip_run){
1836                 int i;
1837                 if(s->pict_type == FF_I_TYPE){
1838                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1839                     return -1;
1840                 }
1841
1842                 /* skip mb */
1843                 s->mb_intra = 0;
1844                 for(i=0;i<12;i++)
1845                     s->block_last_index[i] = -1;
1846                 if(s->picture_structure == PICT_FRAME)
1847                     s->mv_type = MV_TYPE_16X16;
1848                 else
1849                     s->mv_type = MV_TYPE_FIELD;
1850                 if (s->pict_type == FF_P_TYPE) {
1851                     /* if P type, zero motion vector is implied */
1852                     s->mv_dir = MV_DIR_FORWARD;
1853                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1854                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1855                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1856                     s->field_select[0][0]= s->picture_structure - 1;
1857                 } else {
1858                     /* if B type, reuse previous vectors and directions */
1859                     s->mv[0][0][0] = s->last_mv[0][0][0];
1860                     s->mv[0][0][1] = s->last_mv[0][0][1];
1861                     s->mv[1][0][0] = s->last_mv[1][0][0];
1862                     s->mv[1][0][1] = s->last_mv[1][0][1];
1863                 }
1864             }
1865         }
1866     }
1867 eos: // end of slice
1868     *buf += (get_bits_count(&s->gb)-1)/8;
1869 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1870     return 0;
1871 }
1872
1873 static int slice_decode_thread(AVCodecContext *c, void *arg){
1874     MpegEncContext *s= *(void**)arg;
1875     const uint8_t *buf= s->gb.buffer;
1876     int mb_y= s->start_mb_y;
1877
1878     s->error_count= 3*(s->end_mb_y - s->start_mb_y)*s->mb_width;
1879
1880     for(;;){
1881         uint32_t start_code;
1882         int ret;
1883
1884         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1885         emms_c();
1886 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1887 //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);
1888         if(ret < 0){
1889             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1890                 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);
1891         }else{
1892             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);
1893         }
1894
1895         if(s->mb_y == s->end_mb_y)
1896             return 0;
1897
1898         start_code= -1;
1899         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1900         mb_y= start_code - SLICE_MIN_START_CODE;
1901         if(mb_y < 0 || mb_y >= s->end_mb_y)
1902             return -1;
1903     }
1904
1905     return 0; //not reached
1906 }
1907
1908 /**
1909  * Handles slice ends.
1910  * @return 1 if it seems to be the last slice
1911  */
1912 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1913 {
1914     Mpeg1Context *s1 = avctx->priv_data;
1915     MpegEncContext *s = &s1->mpeg_enc_ctx;
1916
1917     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1918         return 0;
1919
1920 #if CONFIG_MPEG_XVMC_DECODER
1921     if(s->avctx->xvmc_acceleration)
1922         ff_xvmc_field_end(s);
1923 #endif
1924     /* end of slice reached */
1925     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1926         /* end of image */
1927
1928         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1929
1930         ff_er_frame_end(s);
1931
1932         MPV_frame_end(s);
1933
1934         if (s->pict_type == FF_B_TYPE || s->low_delay) {
1935             *pict= *(AVFrame*)s->current_picture_ptr;
1936             ff_print_debug_info(s, pict);
1937         } else {
1938             s->picture_number++;
1939             /* latency of 1 frame for I- and P-frames */
1940             /* XXX: use another variable than picture_number */
1941             if (s->last_picture_ptr != NULL) {
1942                 *pict= *(AVFrame*)s->last_picture_ptr;
1943                  ff_print_debug_info(s, pict);
1944             }
1945         }
1946
1947         return 1;
1948     } else {
1949         return 0;
1950     }
1951 }
1952
1953 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1954                                  const uint8_t *buf, int buf_size)
1955 {
1956     Mpeg1Context *s1 = avctx->priv_data;
1957     MpegEncContext *s = &s1->mpeg_enc_ctx;
1958     int width,height;
1959     int i, v, j;
1960
1961     init_get_bits(&s->gb, buf, buf_size*8);
1962
1963     width = get_bits(&s->gb, 12);
1964     height = get_bits(&s->gb, 12);
1965     if (width <= 0 || height <= 0)
1966         return -1;
1967     s->aspect_ratio_info= get_bits(&s->gb, 4);
1968     if (s->aspect_ratio_info == 0) {
1969         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
1970         if (avctx->error_recognition >= FF_ER_COMPLIANT)
1971             return -1;
1972     }
1973     s->frame_rate_index = get_bits(&s->gb, 4);
1974     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
1975         return -1;
1976     s->bit_rate = get_bits(&s->gb, 18) * 400;
1977     if (get_bits1(&s->gb) == 0) /* marker */
1978         return -1;
1979     s->width = width;
1980     s->height = height;
1981
1982     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
1983     skip_bits(&s->gb, 1);
1984
1985     /* get matrix */
1986     if (get_bits1(&s->gb)) {
1987         for(i=0;i<64;i++) {
1988             v = get_bits(&s->gb, 8);
1989             if(v==0){
1990                 av_log(s->avctx, AV_LOG_ERROR, "intra matrix damaged\n");
1991                 return -1;
1992             }
1993             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1994             s->intra_matrix[j] = v;
1995             s->chroma_intra_matrix[j] = v;
1996         }
1997 #ifdef DEBUG
1998         dprintf(s->avctx, "intra matrix present\n");
1999         for(i=0;i<64;i++)
2000             dprintf(s->avctx, " %d", s->intra_matrix[s->dsp.idct_permutation[i]]);
2001         dprintf(s->avctx, "\n");
2002 #endif
2003     } else {
2004         for(i=0;i<64;i++) {
2005             j = s->dsp.idct_permutation[i];
2006             v = ff_mpeg1_default_intra_matrix[i];
2007             s->intra_matrix[j] = v;
2008             s->chroma_intra_matrix[j] = v;
2009         }
2010     }
2011     if (get_bits1(&s->gb)) {
2012         for(i=0;i<64;i++) {
2013             v = get_bits(&s->gb, 8);
2014             if(v==0){
2015                 av_log(s->avctx, AV_LOG_ERROR, "inter matrix damaged\n");
2016                 return -1;
2017             }
2018             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
2019             s->inter_matrix[j] = v;
2020             s->chroma_inter_matrix[j] = v;
2021         }
2022 #ifdef DEBUG
2023         dprintf(s->avctx, "non-intra matrix present\n");
2024         for(i=0;i<64;i++)
2025             dprintf(s->avctx, " %d", s->inter_matrix[s->dsp.idct_permutation[i]]);
2026         dprintf(s->avctx, "\n");
2027 #endif
2028     } else {
2029         for(i=0;i<64;i++) {
2030             int j= s->dsp.idct_permutation[i];
2031             v = ff_mpeg1_default_non_intra_matrix[i];
2032             s->inter_matrix[j] = v;
2033             s->chroma_inter_matrix[j] = v;
2034         }
2035     }
2036
2037     if(show_bits(&s->gb, 23) != 0){
2038         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2039         return -1;
2040     }
2041
2042     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
2043     s->progressive_sequence = 1;
2044     s->progressive_frame = 1;
2045     s->picture_structure = PICT_FRAME;
2046     s->frame_pred_frame_dct = 1;
2047     s->chroma_format = 1;
2048     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2049     avctx->sub_id = 1; /* indicates MPEG-1 */
2050     s->out_format = FMT_MPEG1;
2051     s->swap_uv = 0;//AFAIK VCR2 does not have SEQ_HEADER
2052     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2053
2054     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2055         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2056                s->avctx->rc_buffer_size, s->bit_rate);
2057
2058     return 0;
2059 }
2060
2061 static int vcr2_init_sequence(AVCodecContext *avctx)
2062 {
2063     Mpeg1Context *s1 = avctx->priv_data;
2064     MpegEncContext *s = &s1->mpeg_enc_ctx;
2065     int i, v;
2066
2067     /* start new MPEG-1 context decoding */
2068     s->out_format = FMT_MPEG1;
2069     if (s1->mpeg_enc_ctx_allocated) {
2070         MPV_common_end(s);
2071     }
2072     s->width  = avctx->coded_width;
2073     s->height = avctx->coded_height;
2074     avctx->has_b_frames= 0; //true?
2075     s->low_delay= 1;
2076
2077     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2078
2079     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT ||
2080         s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
2081         if( avctx->idct_algo == FF_IDCT_AUTO )
2082             avctx->idct_algo = FF_IDCT_SIMPLE;
2083
2084     if (MPV_common_init(s) < 0)
2085         return -1;
2086     exchange_uv(s);//common init reset pblocks, so we swap them here
2087     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2088     s1->mpeg_enc_ctx_allocated = 1;
2089
2090     for(i=0;i<64;i++) {
2091         int j= s->dsp.idct_permutation[i];
2092         v = ff_mpeg1_default_intra_matrix[i];
2093         s->intra_matrix[j] = v;
2094         s->chroma_intra_matrix[j] = v;
2095
2096         v = ff_mpeg1_default_non_intra_matrix[i];
2097         s->inter_matrix[j] = v;
2098         s->chroma_inter_matrix[j] = v;
2099     }
2100
2101     s->progressive_sequence = 1;
2102     s->progressive_frame = 1;
2103     s->picture_structure = PICT_FRAME;
2104     s->frame_pred_frame_dct = 1;
2105     s->chroma_format = 1;
2106     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2107     avctx->sub_id = 2; /* indicates MPEG-2 */
2108     return 0;
2109 }
2110
2111
2112 static void mpeg_decode_user_data(AVCodecContext *avctx,
2113                                   const uint8_t *buf, int buf_size)
2114 {
2115     const uint8_t *p;
2116     int len, flags;
2117     p = buf;
2118     len = buf_size;
2119
2120     /* we parse the DTG active format information */
2121     if (len >= 5 &&
2122         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2123         flags = p[4];
2124         p += 5;
2125         len -= 5;
2126         if (flags & 0x80) {
2127             /* skip event id */
2128             if (len < 2)
2129                 return;
2130             p += 2;
2131             len -= 2;
2132         }
2133         if (flags & 0x40) {
2134             if (len < 1)
2135                 return;
2136             avctx->dtg_active_format = p[0] & 0x0f;
2137         }
2138     }
2139 }
2140
2141 static void mpeg_decode_gop(AVCodecContext *avctx,
2142                             const uint8_t *buf, int buf_size){
2143     Mpeg1Context *s1 = avctx->priv_data;
2144     MpegEncContext *s = &s1->mpeg_enc_ctx;
2145
2146     int drop_frame_flag;
2147     int time_code_hours, time_code_minutes;
2148     int time_code_seconds, time_code_pictures;
2149     int closed_gop, broken_link;
2150
2151     init_get_bits(&s->gb, buf, buf_size*8);
2152
2153     drop_frame_flag = get_bits1(&s->gb);
2154
2155     time_code_hours=get_bits(&s->gb,5);
2156     time_code_minutes = get_bits(&s->gb,6);
2157     skip_bits1(&s->gb);//marker bit
2158     time_code_seconds = get_bits(&s->gb,6);
2159     time_code_pictures = get_bits(&s->gb,6);
2160
2161     closed_gop  = get_bits1(&s->gb);
2162     /*broken_link indicate that after editing the
2163       reference frames of the first B-Frames after GOP I-Frame
2164       are missing (open gop)*/
2165     broken_link = get_bits1(&s->gb);
2166
2167     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2168         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2169             time_code_hours, time_code_minutes, time_code_seconds,
2170             time_code_pictures, closed_gop, broken_link);
2171 }
2172 /**
2173  * Finds the end of the current frame in the bitstream.
2174  * @return the position of the first byte of the next frame, or -1
2175  */
2176 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
2177 {
2178     int i;
2179     uint32_t state= pc->state;
2180
2181     /* EOF considered as end of frame */
2182     if (buf_size == 0)
2183         return 0;
2184
2185 /*
2186  0  frame start         -> 1/4
2187  1  first_SEQEXT        -> 0/2
2188  2  first field start   -> 3/0
2189  3  second_SEQEXT       -> 2/0
2190  4  searching end
2191 */
2192
2193     for(i=0; i<buf_size; i++){
2194         assert(pc->frame_start_found>=0 && pc->frame_start_found<=4);
2195         if(pc->frame_start_found&1){
2196             if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80)
2197                 pc->frame_start_found--;
2198             else if(state == EXT_START_CODE+2){
2199                 if((buf[i]&3) == 3) pc->frame_start_found= 0;
2200                 else                pc->frame_start_found= (pc->frame_start_found+1)&3;
2201             }
2202             state++;
2203         }else{
2204             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2205             if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2206                 i++;
2207                 pc->frame_start_found=4;
2208             }
2209             if(state == SEQ_END_CODE){
2210                 pc->state=-1;
2211                 return i+1;
2212             }
2213             if(pc->frame_start_found==2 && state == SEQ_START_CODE)
2214                 pc->frame_start_found= 0;
2215             if(pc->frame_start_found<4 && state == EXT_START_CODE)
2216                 pc->frame_start_found++;
2217             if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){
2218                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2219                     pc->frame_start_found=0;
2220                     pc->state=-1;
2221                     return i-3;
2222                 }
2223             }
2224         }
2225     }
2226     pc->state= state;
2227     return END_NOT_FOUND;
2228 }
2229
2230 static int decode_chunks(AVCodecContext *avctx,
2231                              AVFrame *picture, int *data_size,
2232                              const uint8_t *buf, int buf_size);
2233
2234 /* handle buffering and image synchronisation */
2235 static int mpeg_decode_frame(AVCodecContext *avctx,
2236                              void *data, int *data_size,
2237                              const uint8_t *buf, int buf_size)
2238 {
2239     Mpeg1Context *s = avctx->priv_data;
2240     AVFrame *picture = data;
2241     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2242     dprintf(avctx, "fill_buffer\n");
2243
2244     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2245         /* special case for last picture */
2246         if (s2->low_delay==0 && s2->next_picture_ptr) {
2247             *picture= *(AVFrame*)s2->next_picture_ptr;
2248             s2->next_picture_ptr= NULL;
2249
2250             *data_size = sizeof(AVFrame);
2251         }
2252         return buf_size;
2253     }
2254
2255     if(s2->flags&CODEC_FLAG_TRUNCATED){
2256         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size);
2257
2258         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2259             return buf_size;
2260     }
2261
2262 #if 0
2263     if (s->repeat_field % 2 == 1) {
2264         s->repeat_field++;
2265         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2266         //        s2->picture_number, s->repeat_field);
2267         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2268             *data_size = sizeof(AVPicture);
2269             goto the_end;
2270         }
2271     }
2272 #endif
2273
2274     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == AV_RL32("VCR2"))
2275         vcr2_init_sequence(avctx);
2276
2277     s->slice_count= 0;
2278
2279     if(avctx->extradata && !avctx->frame_number)
2280         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
2281
2282     return decode_chunks(avctx, picture, data_size, buf, buf_size);
2283 }
2284
2285 static int decode_chunks(AVCodecContext *avctx,
2286                              AVFrame *picture, int *data_size,
2287                              const uint8_t *buf, int buf_size)
2288 {
2289     Mpeg1Context *s = avctx->priv_data;
2290     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2291     const uint8_t *buf_ptr = buf;
2292     const uint8_t *buf_end = buf + buf_size;
2293     int ret, input_size;
2294
2295     for(;;) {
2296         /* find next start code */
2297         uint32_t start_code = -1;
2298         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2299         if (start_code > 0x1ff){
2300             if(s2->pict_type != FF_B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2301                 if(avctx->thread_count > 1){
2302                     int i;
2303
2304                     avctx->execute(avctx, slice_decode_thread,  (void**)&(s2->thread_context[0]), NULL, s->slice_count, sizeof(void*));
2305                     for(i=0; i<s->slice_count; i++)
2306                         s2->error_count += s2->thread_context[i]->error_count;
2307                 }
2308
2309                 if (CONFIG_MPEG_VDPAU_DECODER && avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
2310                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2311
2312                 if (slice_end(avctx, picture)) {
2313                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2314                         *data_size = sizeof(AVPicture);
2315                 }
2316             }
2317             s2->pict_type= 0;
2318             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2319         }
2320
2321         input_size = buf_end - buf_ptr;
2322
2323         if(avctx->debug & FF_DEBUG_STARTCODE){
2324             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2325         }
2326
2327         /* prepare data for next start code */
2328         switch(start_code) {
2329         case SEQ_START_CODE:
2330             mpeg1_decode_sequence(avctx, buf_ptr,
2331                                     input_size);
2332             break;
2333
2334         case PICTURE_START_CODE:
2335             /* we have a complete image: we try to decompress it */
2336             if(mpeg1_decode_picture(avctx,
2337                                     buf_ptr, input_size) < 0)
2338                 s2->pict_type=0;
2339             break;
2340         case EXT_START_CODE:
2341             mpeg_decode_extension(avctx,
2342                                     buf_ptr, input_size);
2343             break;
2344         case USER_START_CODE:
2345             mpeg_decode_user_data(avctx,
2346                                     buf_ptr, input_size);
2347             break;
2348         case GOP_START_CODE:
2349             s2->first_field=0;
2350             mpeg_decode_gop(avctx,
2351                                     buf_ptr, input_size);
2352             break;
2353         default:
2354             if (start_code >= SLICE_MIN_START_CODE &&
2355                 start_code <= SLICE_MAX_START_CODE) {
2356                 int mb_y= start_code - SLICE_MIN_START_CODE;
2357
2358                 if(s2->last_picture_ptr==NULL){
2359                 /* Skip B-frames if we do not have reference frames. */
2360                     if(s2->pict_type==FF_B_TYPE) break;
2361                 }
2362                 if(s2->next_picture_ptr==NULL){
2363                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2364                     if(s2->pict_type==FF_P_TYPE && (s2->first_field || s2->picture_structure==PICT_FRAME)) break;
2365                 }
2366                 /* Skip B-frames if we are in a hurry. */
2367                 if(avctx->hurry_up && s2->pict_type==FF_B_TYPE) break;
2368                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==FF_B_TYPE)
2369                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=FF_I_TYPE)
2370                     || avctx->skip_frame >= AVDISCARD_ALL)
2371                     break;
2372                 /* Skip everything if we are in a hurry>=5. */
2373                 if(avctx->hurry_up>=5) break;
2374
2375                 if (!s->mpeg_enc_ctx_allocated) break;
2376
2377                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2378                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2379                         break;
2380                 }
2381
2382                 if(!s2->pict_type){
2383                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2384                     break;
2385                 }
2386
2387                 if(s2->first_slice){
2388                     s2->first_slice=0;
2389                             if(mpeg_field_start(s2) < 0)
2390                         return -1;
2391                     }
2392                 if(!s2->current_picture_ptr){
2393                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2394                     return -1;
2395                 }
2396
2397                 if (avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU) {
2398                     s->slice_count++;
2399                     break;
2400                 }
2401
2402                 if(avctx->thread_count > 1){
2403                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2404                     if(threshold <= mb_y){
2405                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2406
2407                         thread_context->start_mb_y= mb_y;
2408                         thread_context->end_mb_y  = s2->mb_height;
2409                         if(s->slice_count){
2410                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2411                             ff_update_duplicate_context(thread_context, s2);
2412                         }
2413                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2414                         s->slice_count++;
2415                     }
2416                     buf_ptr += 2; //FIXME add minimum number of bytes per slice
2417                 }else{
2418                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2419                     emms_c();
2420
2421                     if(ret < 0){
2422                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2423                             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);
2424                     }else{
2425                         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);
2426                     }
2427                 }
2428             }
2429             break;
2430         }
2431     }
2432 }
2433
2434 static int mpeg_decode_end(AVCodecContext *avctx)
2435 {
2436     Mpeg1Context *s = avctx->priv_data;
2437
2438     if (s->mpeg_enc_ctx_allocated)
2439         MPV_common_end(&s->mpeg_enc_ctx);
2440     return 0;
2441 }
2442
2443 AVCodec mpeg1video_decoder = {
2444     "mpeg1video",
2445     CODEC_TYPE_VIDEO,
2446     CODEC_ID_MPEG1VIDEO,
2447     sizeof(Mpeg1Context),
2448     mpeg_decode_init,
2449     NULL,
2450     mpeg_decode_end,
2451     mpeg_decode_frame,
2452     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2453     .flush= ff_mpeg_flush,
2454     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2455 };
2456
2457 AVCodec mpeg2video_decoder = {
2458     "mpeg2video",
2459     CODEC_TYPE_VIDEO,
2460     CODEC_ID_MPEG2VIDEO,
2461     sizeof(Mpeg1Context),
2462     mpeg_decode_init,
2463     NULL,
2464     mpeg_decode_end,
2465     mpeg_decode_frame,
2466     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2467     .flush= ff_mpeg_flush,
2468     .long_name= NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2469 };
2470
2471 //legacy decoder
2472 AVCodec mpegvideo_decoder = {
2473     "mpegvideo",
2474     CODEC_TYPE_VIDEO,
2475     CODEC_ID_MPEG2VIDEO,
2476     sizeof(Mpeg1Context),
2477     mpeg_decode_init,
2478     NULL,
2479     mpeg_decode_end,
2480     mpeg_decode_frame,
2481     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2482     .flush= ff_mpeg_flush,
2483     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2484 };
2485
2486 #if CONFIG_MPEG_XVMC_DECODER
2487 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx){
2488     Mpeg1Context *s;
2489
2490     if( avctx->thread_count > 1)
2491         return -1;
2492     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2493         return -1;
2494     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2495         dprintf(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2496     }
2497     mpeg_decode_init(avctx);
2498     s = avctx->priv_data;
2499
2500     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2501     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2502
2503     return 0;
2504 }
2505
2506 AVCodec mpeg_xvmc_decoder = {
2507     "mpegvideo_xvmc",
2508     CODEC_TYPE_VIDEO,
2509     CODEC_ID_MPEG2VIDEO_XVMC,
2510     sizeof(Mpeg1Context),
2511     mpeg_mc_decode_init,
2512     NULL,
2513     mpeg_decode_end,
2514     mpeg_decode_frame,
2515     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2516     .flush= ff_mpeg_flush,
2517     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video XvMC (X-Video Motion Compensation)"),
2518 };
2519
2520 #endif
2521
2522 #if CONFIG_MPEG_VDPAU_DECODER
2523 AVCodec mpeg_vdpau_decoder = {
2524     "mpegvideo_vdpau",
2525     CODEC_TYPE_VIDEO,
2526     CODEC_ID_MPEG2VIDEO,
2527     sizeof(Mpeg1Context),
2528     mpeg_decode_init,
2529     NULL,
2530     mpeg_decode_end,
2531     mpeg_decode_frame,
2532     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2533     .flush= ff_mpeg_flush,
2534     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2535 };
2536 #endif
2537
2538 #if CONFIG_MPEG1_VDPAU_DECODER
2539 AVCodec mpeg1_vdpau_decoder = {
2540     "mpeg1video_vdpau",
2541     CODEC_TYPE_VIDEO,
2542     CODEC_ID_MPEG1VIDEO,
2543     sizeof(Mpeg1Context),
2544     mpeg_decode_init,
2545     NULL,
2546     mpeg_decode_end,
2547     mpeg_decode_frame,
2548     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2549     .flush= ff_mpeg_flush,
2550     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2551 };
2552 #endif
2553