mpeg12: Move Mpeg1Context declaration to the only place it is used
[ffmpeg.git] / libavcodec / mpeg12dec.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 Libav.
7  *
8  * Libav 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  * Libav 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 Libav; 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
25  * MPEG-1/2 decoder
26  */
27
28 //#define DEBUG
29 #include "libavutil/internal.h"
30 #include "internal.h"
31 #include "avcodec.h"
32 #include "dsputil.h"
33 #include "mpegvideo.h"
34 #include "error_resilience.h"
35 #include "mpeg12.h"
36 #include "mpeg12data.h"
37 #include "mpeg12decdata.h"
38 #include "bytestream.h"
39 #include "vdpau_internal.h"
40 #include "xvmc_internal.h"
41 #include "thread.h"
42
43 //#undef NDEBUG
44 //#include <assert.h>
45
46 typedef struct Mpeg1Context {
47     MpegEncContext mpeg_enc_ctx;
48     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
49     int repeat_field; /* true if we must repeat the field */
50     AVPanScan pan_scan;              /**< some temporary storage for the panscan */
51     int slice_count;
52     int swap_uv;//indicate VCR2
53     int save_aspect_info;
54     int save_width, save_height, save_progressive_seq;
55     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
56     int sync;                        ///< Did we reach a sync point like a GOP/SEQ/KEYFrame?
57     int closed_gop;                  ///< GOP is closed
58     int extradata_decoded;
59 } Mpeg1Context;
60
61 /* as H.263, but only 17 codes */
62 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
63 {
64     int code, sign, val, shift;
65
66     code = get_vlc2(&s->gb, ff_mv_vlc.table, MV_VLC_BITS, 2);
67     if (code == 0) {
68         return pred;
69     }
70     if (code < 0) {
71         return 0xffff;
72     }
73
74     sign  = get_bits1(&s->gb);
75     shift = fcode - 1;
76     val   = code;
77     if (shift) {
78         val  = (val - 1) << shift;
79         val |= get_bits(&s->gb, shift);
80         val++;
81     }
82     if (sign)
83         val = -val;
84     val += pred;
85
86     /* modulo decoding */
87     return sign_extend(val, 5 + shift);
88 }
89
90 static inline int mpeg1_decode_block_intra(MpegEncContext *s, int16_t *block, int n)
91 {
92     int level, dc, diff, i, j, run;
93     int component;
94     RLTable *rl = &ff_rl_mpeg1;
95     uint8_t * const scantable    = s->intra_scantable.permutated;
96     const uint16_t *quant_matrix = s->intra_matrix;
97     const int qscale             = s->qscale;
98
99     /* DC coefficient */
100     component = (n <= 3 ? 0 : n - 4 + 1);
101     diff = decode_dc(&s->gb, component);
102     if (diff >= 0xffff)
103         return -1;
104     dc  = s->last_dc[component];
105     dc += diff;
106     s->last_dc[component] = dc;
107     block[0] = dc * quant_matrix[0];
108     av_dlog(s->avctx, "dc=%d diff=%d\n", dc, diff);
109     i = 0;
110     {
111         OPEN_READER(re, &s->gb);
112         /* now quantify & encode AC coefficients */
113         for (;;) {
114             UPDATE_CACHE(re, &s->gb);
115             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
116
117             if (level == 127) {
118                 break;
119             } else if (level != 0) {
120                 i += run;
121                 j = scantable[i];
122                 level = (level * qscale * quant_matrix[j]) >> 4;
123                 level = (level - 1) | 1;
124                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
125                 LAST_SKIP_BITS(re, &s->gb, 1);
126             } else {
127                 /* escape */
128                 run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
129                 UPDATE_CACHE(re, &s->gb);
130                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
131                 if (level == -128) {
132                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
133                 } else if (level == 0) {
134                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
135                 }
136                 i += run;
137                 j = scantable[i];
138                 if (level < 0) {
139                     level = -level;
140                     level = (level * qscale * quant_matrix[j]) >> 4;
141                     level = (level - 1) | 1;
142                     level = -level;
143                 } else {
144                     level = (level * qscale * quant_matrix[j]) >> 4;
145                     level = (level - 1) | 1;
146                 }
147             }
148             if (i > 63) {
149                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
150                 return -1;
151             }
152
153             block[j] = level;
154         }
155         CLOSE_READER(re, &s->gb);
156     }
157     s->block_last_index[n] = i;
158    return 0;
159 }
160
161 int ff_mpeg1_decode_block_intra(MpegEncContext *s, int16_t *block, int n)
162 {
163     return mpeg1_decode_block_intra(s, block, n);
164 }
165
166 static inline int mpeg1_decode_block_inter(MpegEncContext *s, int16_t *block, int n)
167 {
168     int level, i, j, run;
169     RLTable *rl = &ff_rl_mpeg1;
170     uint8_t * const scantable    = s->intra_scantable.permutated;
171     const uint16_t *quant_matrix = s->inter_matrix;
172     const int qscale             = s->qscale;
173
174     {
175         OPEN_READER(re, &s->gb);
176         i = -1;
177         // special case for first coefficient, no need to add second VLC table
178         UPDATE_CACHE(re, &s->gb);
179         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
180             level = (3 * qscale * quant_matrix[0]) >> 5;
181             level = (level - 1) | 1;
182             if (GET_CACHE(re, &s->gb) & 0x40000000)
183                 level = -level;
184             block[0] = level;
185             i++;
186             SKIP_BITS(re, &s->gb, 2);
187             if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
188                 goto end;
189         }
190         /* now quantify & encode AC coefficients */
191         for (;;) {
192             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
193
194             if (level != 0) {
195                 i += run;
196                 j = scantable[i];
197                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
198                 level = (level - 1) | 1;
199                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
200                 SKIP_BITS(re, &s->gb, 1);
201             } else {
202                 /* escape */
203                 run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
204                 UPDATE_CACHE(re, &s->gb);
205                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
206                 if (level == -128) {
207                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
208                 } else if (level == 0) {
209                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
210                 }
211                 i += run;
212                 j = scantable[i];
213                 if (level < 0) {
214                     level = -level;
215                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
216                     level = (level - 1) | 1;
217                     level = -level;
218                 } else {
219                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
220                     level = (level - 1) | 1;
221                 }
222             }
223             if (i > 63) {
224                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
225                 return -1;
226             }
227
228             block[j] = level;
229             if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
230                 break;
231             UPDATE_CACHE(re, &s->gb);
232         }
233 end:
234         LAST_SKIP_BITS(re, &s->gb, 2);
235         CLOSE_READER(re, &s->gb);
236     }
237     s->block_last_index[n] = i;
238     return 0;
239 }
240
241 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, int16_t *block, int n)
242 {
243     int level, i, j, run;
244     RLTable *rl = &ff_rl_mpeg1;
245     uint8_t * const scantable = s->intra_scantable.permutated;
246     const int qscale          = s->qscale;
247
248     {
249         OPEN_READER(re, &s->gb);
250         i = -1;
251         // special case for first coefficient, no need to add second VLC table
252         UPDATE_CACHE(re, &s->gb);
253         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
254             level = (3 * qscale) >> 1;
255             level = (level - 1) | 1;
256             if (GET_CACHE(re, &s->gb) & 0x40000000)
257                 level = -level;
258             block[0] = level;
259             i++;
260             SKIP_BITS(re, &s->gb, 2);
261             if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
262                 goto end;
263         }
264
265         /* now quantify & encode AC coefficients */
266         for (;;) {
267             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
268
269             if (level != 0) {
270                 i += run;
271                 j = scantable[i];
272                 level = ((level * 2 + 1) * qscale) >> 1;
273                 level = (level - 1) | 1;
274                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
275                 SKIP_BITS(re, &s->gb, 1);
276             } else {
277                 /* escape */
278                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
279                 UPDATE_CACHE(re, &s->gb);
280                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
281                 if (level == -128) {
282                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
283                 } else if (level == 0) {
284                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
285                 }
286                 i += run;
287                 j = scantable[i];
288                 if (level < 0) {
289                     level = -level;
290                     level = ((level * 2 + 1) * qscale) >> 1;
291                     level = (level - 1) | 1;
292                     level = -level;
293                 } else {
294                     level = ((level * 2 + 1) * qscale) >> 1;
295                     level = (level - 1) | 1;
296                 }
297             }
298
299             block[j] = level;
300             if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
301                 break;
302             UPDATE_CACHE(re, &s->gb);
303         }
304 end:
305         LAST_SKIP_BITS(re, &s->gb, 2);
306         CLOSE_READER(re, &s->gb);
307     }
308     s->block_last_index[n] = i;
309     return 0;
310 }
311
312
313 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s, int16_t *block, int n)
314 {
315     int level, i, j, run;
316     RLTable *rl = &ff_rl_mpeg1;
317     uint8_t * const scantable = s->intra_scantable.permutated;
318     const uint16_t *quant_matrix;
319     const int qscale = s->qscale;
320     int mismatch;
321
322     mismatch = 1;
323
324     {
325         OPEN_READER(re, &s->gb);
326         i = -1;
327         if (n < 4)
328             quant_matrix = s->inter_matrix;
329         else
330             quant_matrix = s->chroma_inter_matrix;
331
332         // special case for first coefficient, no need to add second VLC table
333         UPDATE_CACHE(re, &s->gb);
334         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
335             level= (3 * qscale * quant_matrix[0]) >> 5;
336             if (GET_CACHE(re, &s->gb) & 0x40000000)
337                 level = -level;
338             block[0]  = level;
339             mismatch ^= level;
340             i++;
341             SKIP_BITS(re, &s->gb, 2);
342             if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
343                 goto end;
344         }
345
346         /* now quantify & encode AC coefficients */
347         for (;;) {
348             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
349
350             if (level != 0) {
351                 i += run;
352                 j = scantable[i];
353                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
354                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
355                 SKIP_BITS(re, &s->gb, 1);
356             } else {
357                 /* escape */
358                 run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
359                 UPDATE_CACHE(re, &s->gb);
360                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
361
362                 i += run;
363                 j = scantable[i];
364                 if (level < 0) {
365                     level = ((-level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
366                     level = -level;
367                 } else {
368                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
369                 }
370             }
371             if (i > 63) {
372                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
373                 return -1;
374             }
375
376             mismatch ^= level;
377             block[j]  = level;
378             if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
379                 break;
380             UPDATE_CACHE(re, &s->gb);
381         }
382 end:
383         LAST_SKIP_BITS(re, &s->gb, 2);
384         CLOSE_READER(re, &s->gb);
385     }
386     block[63] ^= (mismatch & 1);
387
388     s->block_last_index[n] = i;
389     return 0;
390 }
391
392 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
393                                                     int16_t *block, int n)
394 {
395     int level, i, j, run;
396     RLTable *rl = &ff_rl_mpeg1;
397     uint8_t * const scantable = s->intra_scantable.permutated;
398     const int qscale          = s->qscale;
399     OPEN_READER(re, &s->gb);
400     i = -1;
401
402     // special case for first coefficient, no need to add second VLC table
403     UPDATE_CACHE(re, &s->gb);
404     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
405         level = (3 * qscale) >> 1;
406         if (GET_CACHE(re, &s->gb) & 0x40000000)
407             level = -level;
408         block[0] = level;
409         i++;
410         SKIP_BITS(re, &s->gb, 2);
411         if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
412             goto end;
413     }
414
415     /* now quantify & encode AC coefficients */
416     for (;;) {
417         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
418
419         if (level != 0) {
420             i += run;
421             j  = scantable[i];
422             level = ((level * 2 + 1) * qscale) >> 1;
423             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
424             SKIP_BITS(re, &s->gb, 1);
425         } else {
426             /* escape */
427             run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
428             UPDATE_CACHE(re, &s->gb);
429             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
430
431             i += run;
432             j  = scantable[i];
433             if (level < 0) {
434                 level = ((-level * 2 + 1) * qscale) >> 1;
435                 level = -level;
436             } else {
437                 level = ((level * 2 + 1) * qscale) >> 1;
438             }
439         }
440
441         block[j] = level;
442         if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
443             break;
444         UPDATE_CACHE(re, &s->gb);
445     }
446 end:
447     LAST_SKIP_BITS(re, &s->gb, 2);
448     CLOSE_READER(re, &s->gb);
449     s->block_last_index[n] = i;
450     return 0;
451 }
452
453
454 static inline int mpeg2_decode_block_intra(MpegEncContext *s, int16_t *block, int n)
455 {
456     int level, dc, diff, i, j, run;
457     int component;
458     RLTable *rl;
459     uint8_t * const scantable = s->intra_scantable.permutated;
460     const uint16_t *quant_matrix;
461     const int qscale = s->qscale;
462     int mismatch;
463
464     /* DC coefficient */
465     if (n < 4) {
466         quant_matrix = s->intra_matrix;
467         component = 0;
468     } else {
469         quant_matrix = s->chroma_intra_matrix;
470         component = (n & 1) + 1;
471     }
472     diff = decode_dc(&s->gb, component);
473     if (diff >= 0xffff)
474         return -1;
475     dc  = s->last_dc[component];
476     dc += diff;
477     s->last_dc[component] = dc;
478     block[0] = dc << (3 - s->intra_dc_precision);
479     av_dlog(s->avctx, "dc=%d\n", block[0]);
480     mismatch = block[0] ^ 1;
481     i = 0;
482     if (s->intra_vlc_format)
483         rl = &ff_rl_mpeg2;
484     else
485         rl = &ff_rl_mpeg1;
486
487     {
488         OPEN_READER(re, &s->gb);
489         /* now quantify & encode AC coefficients */
490         for (;;) {
491             UPDATE_CACHE(re, &s->gb);
492             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
493
494             if (level == 127) {
495                 break;
496             } else if (level != 0) {
497                 i += run;
498                 j  = scantable[i];
499                 level = (level * qscale * quant_matrix[j]) >> 4;
500                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
501                 LAST_SKIP_BITS(re, &s->gb, 1);
502             } else {
503                 /* escape */
504                 run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
505                 UPDATE_CACHE(re, &s->gb);
506                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
507                 i += run;
508                 j  = scantable[i];
509                 if (level < 0) {
510                     level = (-level * qscale * quant_matrix[j]) >> 4;
511                     level = -level;
512                 } else {
513                     level = (level * qscale * quant_matrix[j]) >> 4;
514                 }
515             }
516             if (i > 63) {
517                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
518                 return -1;
519             }
520
521             mismatch ^= level;
522             block[j]  = level;
523         }
524         CLOSE_READER(re, &s->gb);
525     }
526     block[63] ^= mismatch & 1;
527
528     s->block_last_index[n] = i;
529     return 0;
530 }
531
532 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, int16_t *block, int n)
533 {
534     int level, dc, diff, j, run;
535     int component;
536     RLTable *rl;
537     uint8_t * scantable = s->intra_scantable.permutated;
538     const uint16_t *quant_matrix;
539     const int qscale = s->qscale;
540
541     /* DC coefficient */
542     if (n < 4) {
543         quant_matrix = s->intra_matrix;
544         component = 0;
545     } else {
546         quant_matrix = s->chroma_intra_matrix;
547         component = (n & 1) + 1;
548     }
549     diff = decode_dc(&s->gb, component);
550     if (diff >= 0xffff)
551         return -1;
552     dc = s->last_dc[component];
553     dc += diff;
554     s->last_dc[component] = dc;
555     block[0] = dc << (3 - s->intra_dc_precision);
556     if (s->intra_vlc_format)
557         rl = &ff_rl_mpeg2;
558     else
559         rl = &ff_rl_mpeg1;
560
561     {
562         OPEN_READER(re, &s->gb);
563         /* now quantify & encode AC coefficients */
564         for (;;) {
565             UPDATE_CACHE(re, &s->gb);
566             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
567
568             if (level == 127) {
569                 break;
570             } else if (level != 0) {
571                 scantable += run;
572                 j = *scantable;
573                 level = (level * qscale * quant_matrix[j]) >> 4;
574                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
575                 LAST_SKIP_BITS(re, &s->gb, 1);
576             } else {
577                 /* escape */
578                 run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
579                 UPDATE_CACHE(re, &s->gb);
580                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
581                 scantable += run;
582                 j = *scantable;
583                 if (level < 0) {
584                     level = (-level * qscale * quant_matrix[j]) >> 4;
585                     level = -level;
586                 } else {
587                     level = (level * qscale * quant_matrix[j]) >> 4;
588                 }
589             }
590
591             block[j] = level;
592         }
593         CLOSE_READER(re, &s->gb);
594     }
595
596     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
597     return 0;
598 }
599
600 /******************************************/
601 /* decoding */
602
603 static inline int get_dmv(MpegEncContext *s)
604 {
605     if (get_bits1(&s->gb))
606         return 1 - (get_bits1(&s->gb) << 1);
607     else
608         return 0;
609 }
610
611 static inline int get_qscale(MpegEncContext *s)
612 {
613     int qscale = get_bits(&s->gb, 5);
614     if (s->q_scale_type) {
615         return non_linear_qscale[qscale];
616     } else {
617         return qscale << 1;
618     }
619 }
620
621 static void exchange_uv(MpegEncContext *s)
622 {
623     int16_t (*tmp)[64];
624
625     tmp           = s->pblocks[4];
626     s->pblocks[4] = s->pblocks[5];
627     s->pblocks[5] = tmp;
628 }
629
630 /* motion type (for MPEG-2) */
631 #define MT_FIELD 1
632 #define MT_FRAME 2
633 #define MT_16X8  2
634 #define MT_DMV   3
635
636 static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
637 {
638     int i, j, k, cbp, val, mb_type, motion_type;
639     const int mb_block_count = 4 + (1 << s->chroma_format);
640
641     av_dlog(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
642
643     assert(s->mb_skipped == 0);
644
645     if (s->mb_skip_run-- != 0) {
646         if (s->pict_type == AV_PICTURE_TYPE_P) {
647             s->mb_skipped = 1;
648             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] = MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
649         } else {
650             int mb_type;
651
652             if (s->mb_x)
653                 mb_type = s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride - 1];
654             else
655                 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
656             if (IS_INTRA(mb_type))
657                 return -1;
658             s->current_picture.mb_type[s->mb_x + s->mb_y*s->mb_stride] =
659                 mb_type | MB_TYPE_SKIP;
660 //            assert(s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride - 1] & (MB_TYPE_16x16 | MB_TYPE_16x8));
661
662             if ((s->mv[0][0][0] | s->mv[0][0][1] | s->mv[1][0][0] | s->mv[1][0][1]) == 0)
663                 s->mb_skipped = 1;
664         }
665
666         return 0;
667     }
668
669     switch (s->pict_type) {
670     default:
671     case AV_PICTURE_TYPE_I:
672         if (get_bits1(&s->gb) == 0) {
673             if (get_bits1(&s->gb) == 0) {
674                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
675                 return -1;
676             }
677             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
678         } else {
679             mb_type = MB_TYPE_INTRA;
680         }
681         break;
682     case AV_PICTURE_TYPE_P:
683         mb_type = get_vlc2(&s->gb, ff_mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
684         if (mb_type < 0) {
685             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
686             return -1;
687         }
688         mb_type = ptype2mb_type[mb_type];
689         break;
690     case AV_PICTURE_TYPE_B:
691         mb_type = get_vlc2(&s->gb, ff_mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
692         if (mb_type < 0) {
693             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
694             return -1;
695         }
696         mb_type = btype2mb_type[mb_type];
697         break;
698     }
699     av_dlog(s->avctx, "mb_type=%x\n", mb_type);
700 //    motion_type = 0; /* avoid warning */
701     if (IS_INTRA(mb_type)) {
702         s->dsp.clear_blocks(s->block[0]);
703
704         if (!s->chroma_y_shift) {
705             s->dsp.clear_blocks(s->block[6]);
706         }
707
708         /* compute DCT type */
709         if (s->picture_structure == PICT_FRAME && // FIXME add an interlaced_dct coded var?
710             !s->frame_pred_frame_dct) {
711             s->interlaced_dct = get_bits1(&s->gb);
712         }
713
714         if (IS_QUANT(mb_type))
715             s->qscale = get_qscale(s);
716
717         if (s->concealment_motion_vectors) {
718             /* just parse them */
719             if (s->picture_structure != PICT_FRAME)
720                 skip_bits1(&s->gb); /* field select */
721
722             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
723                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
724             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
725                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
726
727             skip_bits1(&s->gb); /* marker */
728         } else
729             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
730         s->mb_intra = 1;
731         // if 1, we memcpy blocks in xvmcvideo
732         if (CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1) {
733             ff_xvmc_pack_pblocks(s, -1); // inter are always full blocks
734             if (s->swap_uv) {
735                 exchange_uv(s);
736             }
737         }
738
739         if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
740             if (s->flags2 & CODEC_FLAG2_FAST) {
741                 for (i = 0; i < 6; i++) {
742                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
743                 }
744             } else {
745                 for (i = 0; i < mb_block_count; i++) {
746                     if (mpeg2_decode_block_intra(s, *s->pblocks[i], i) < 0)
747                         return -1;
748                 }
749             }
750         } else {
751             for (i = 0; i < 6; i++) {
752                 if (mpeg1_decode_block_intra(s, *s->pblocks[i], i) < 0)
753                     return -1;
754             }
755         }
756     } else {
757         if (mb_type & MB_TYPE_ZERO_MV) {
758             assert(mb_type & MB_TYPE_CBP);
759
760             s->mv_dir = MV_DIR_FORWARD;
761             if (s->picture_structure == PICT_FRAME) {
762                 if (!s->frame_pred_frame_dct)
763                     s->interlaced_dct = get_bits1(&s->gb);
764                 s->mv_type = MV_TYPE_16X16;
765             } else {
766                 s->mv_type = MV_TYPE_FIELD;
767                 mb_type |= MB_TYPE_INTERLACED;
768                 s->field_select[0][0] = s->picture_structure - 1;
769             }
770
771             if (IS_QUANT(mb_type))
772                 s->qscale = get_qscale(s);
773
774             s->last_mv[0][0][0] = 0;
775             s->last_mv[0][0][1] = 0;
776             s->last_mv[0][1][0] = 0;
777             s->last_mv[0][1][1] = 0;
778             s->mv[0][0][0] = 0;
779             s->mv[0][0][1] = 0;
780         } else {
781             assert(mb_type & MB_TYPE_L0L1);
782             // FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
783             /* get additional motion vector type */
784             if (s->frame_pred_frame_dct)
785                 motion_type = MT_FRAME;
786             else {
787                 motion_type = get_bits(&s->gb, 2);
788                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
789                     s->interlaced_dct = get_bits1(&s->gb);
790             }
791
792             if (IS_QUANT(mb_type))
793                 s->qscale = get_qscale(s);
794
795             /* motion vectors */
796             s->mv_dir = (mb_type >> 13) & 3;
797             av_dlog(s->avctx, "motion_type=%d\n", motion_type);
798             switch (motion_type) {
799             case MT_FRAME: /* or MT_16X8 */
800                 if (s->picture_structure == PICT_FRAME) {
801                     mb_type |= MB_TYPE_16x16;
802                     s->mv_type = MV_TYPE_16X16;
803                     for (i = 0; i < 2; i++) {
804                         if (USES_LIST(mb_type, i)) {
805                             /* MT_FRAME */
806                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
807                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
808                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
809                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
810                             /* full_pel: only for MPEG-1 */
811                             if (s->full_pel[i]) {
812                                 s->mv[i][0][0] <<= 1;
813                                 s->mv[i][0][1] <<= 1;
814                             }
815                         }
816                     }
817                 } else {
818                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
819                     s->mv_type = MV_TYPE_16X8;
820                     for (i = 0; i < 2; i++) {
821                         if (USES_LIST(mb_type, i)) {
822                             /* MT_16X8 */
823                             for (j = 0; j < 2; j++) {
824                                 s->field_select[i][j] = get_bits1(&s->gb);
825                                 for (k = 0; k < 2; k++) {
826                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
827                                                              s->last_mv[i][j][k]);
828                                     s->last_mv[i][j][k] = val;
829                                     s->mv[i][j][k]      = val;
830                                 }
831                             }
832                         }
833                     }
834                 }
835                 break;
836             case MT_FIELD:
837                 s->mv_type = MV_TYPE_FIELD;
838                 if (s->picture_structure == PICT_FRAME) {
839                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
840                     for (i = 0; i < 2; i++) {
841                         if (USES_LIST(mb_type, i)) {
842                             for (j = 0; j < 2; j++) {
843                                 s->field_select[i][j] = get_bits1(&s->gb);
844                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
845                                                          s->last_mv[i][j][0]);
846                                 s->last_mv[i][j][0] = val;
847                                 s->mv[i][j][0]      = val;
848                                 av_dlog(s->avctx, "fmx=%d\n", val);
849                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
850                                                          s->last_mv[i][j][1] >> 1);
851                                 s->last_mv[i][j][1] = val << 1;
852                                 s->mv[i][j][1]      = val;
853                                 av_dlog(s->avctx, "fmy=%d\n", val);
854                             }
855                         }
856                     }
857                 } else {
858                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
859                     for (i = 0; i < 2; i++) {
860                         if (USES_LIST(mb_type, i)) {
861                             s->field_select[i][0] = get_bits1(&s->gb);
862                             for (k = 0; k < 2; k++) {
863                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
864                                                          s->last_mv[i][0][k]);
865                                 s->last_mv[i][0][k] = val;
866                                 s->last_mv[i][1][k] = val;
867                                 s->mv[i][0][k]      = val;
868                             }
869                         }
870                     }
871                 }
872                 break;
873             case MT_DMV:
874                 s->mv_type = MV_TYPE_DMV;
875                 for (i = 0; i < 2; i++) {
876                     if (USES_LIST(mb_type, i)) {
877                         int dmx, dmy, mx, my, m;
878                         const int my_shift = s->picture_structure == PICT_FRAME;
879
880                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
881                                                 s->last_mv[i][0][0]);
882                         s->last_mv[i][0][0] = mx;
883                         s->last_mv[i][1][0] = mx;
884                         dmx = get_dmv(s);
885                         my  = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
886                                                  s->last_mv[i][0][1] >> my_shift);
887                         dmy = get_dmv(s);
888
889
890                         s->last_mv[i][0][1] = my << my_shift;
891                         s->last_mv[i][1][1] = my << my_shift;
892
893                         s->mv[i][0][0] = mx;
894                         s->mv[i][0][1] = my;
895                         s->mv[i][1][0] = mx; // not used
896                         s->mv[i][1][1] = my; // not used
897
898                         if (s->picture_structure == PICT_FRAME) {
899                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
900
901                             // m = 1 + 2 * s->top_field_first;
902                             m = s->top_field_first ? 1 : 3;
903
904                             /* top -> top pred */
905                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
906                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
907                             m = 4 - m;
908                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
909                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
910                         } else {
911                             mb_type |= MB_TYPE_16x16;
912
913                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
914                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
915                             if (s->picture_structure == PICT_TOP_FIELD)
916                                 s->mv[i][2][1]--;
917                             else
918                                 s->mv[i][2][1]++;
919                         }
920                     }
921                 }
922                 break;
923             default:
924                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
925                 return -1;
926             }
927         }
928
929         s->mb_intra = 0;
930         if (HAS_CBP(mb_type)) {
931             s->dsp.clear_blocks(s->block[0]);
932
933             cbp = get_vlc2(&s->gb, ff_mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
934             if (mb_block_count > 6) {
935                  cbp <<= mb_block_count - 6;
936                  cbp  |= get_bits(&s->gb, mb_block_count - 6);
937                  s->dsp.clear_blocks(s->block[6]);
938             }
939             if (cbp <= 0) {
940                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
941                 return -1;
942             }
943
944             //if 1, we memcpy blocks in xvmcvideo
945             if (CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1) {
946                 ff_xvmc_pack_pblocks(s, cbp);
947                 if (s->swap_uv) {
948                     exchange_uv(s);
949                 }
950             }
951
952             if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
953                 if (s->flags2 & CODEC_FLAG2_FAST) {
954                     for (i = 0; i < 6; i++) {
955                         if (cbp & 32) {
956                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
957                         } else {
958                             s->block_last_index[i] = -1;
959                         }
960                         cbp += cbp;
961                     }
962                 } else {
963                     cbp <<= 12-mb_block_count;
964
965                     for (i = 0; i < mb_block_count; i++) {
966                         if (cbp & (1 << 11)) {
967                             if (mpeg2_decode_block_non_intra(s, *s->pblocks[i], i) < 0)
968                                 return -1;
969                         } else {
970                             s->block_last_index[i] = -1;
971                         }
972                         cbp += cbp;
973                     }
974                 }
975             } else {
976                 if (s->flags2 & CODEC_FLAG2_FAST) {
977                     for (i = 0; i < 6; i++) {
978                         if (cbp & 32) {
979                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
980                         } else {
981                             s->block_last_index[i] = -1;
982                         }
983                         cbp += cbp;
984                     }
985                 } else {
986                     for (i = 0; i < 6; i++) {
987                         if (cbp & 32) {
988                             if (mpeg1_decode_block_inter(s, *s->pblocks[i], i) < 0)
989                                 return -1;
990                         } else {
991                             s->block_last_index[i] = -1;
992                         }
993                         cbp += cbp;
994                     }
995                 }
996             }
997         } else {
998             for (i = 0; i < 12; i++)
999                 s->block_last_index[i] = -1;
1000         }
1001     }
1002
1003     s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] = mb_type;
1004
1005     return 0;
1006 }
1007
1008 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1009 {
1010     Mpeg1Context *s = avctx->priv_data;
1011     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1012     int i;
1013
1014     /* we need some permutation to store matrices,
1015      * until MPV_common_init() sets the real permutation. */
1016     for (i = 0; i < 64; i++)
1017        s2->dsp.idct_permutation[i]=i;
1018
1019     ff_MPV_decode_defaults(s2);
1020
1021     s->mpeg_enc_ctx.avctx  = avctx;
1022     s->mpeg_enc_ctx.flags  = avctx->flags;
1023     s->mpeg_enc_ctx.flags2 = avctx->flags2;
1024     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1025     ff_mpeg12_init_vlcs();
1026
1027     s->mpeg_enc_ctx_allocated      = 0;
1028     s->mpeg_enc_ctx.picture_number = 0;
1029     s->repeat_field                = 0;
1030     s->mpeg_enc_ctx.codec_id       = avctx->codec->id;
1031     avctx->color_range = AVCOL_RANGE_MPEG;
1032     if (avctx->codec->id == AV_CODEC_ID_MPEG1VIDEO)
1033         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1034     else
1035         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
1036     return 0;
1037 }
1038
1039 static int mpeg_decode_update_thread_context(AVCodecContext *avctx, const AVCodecContext *avctx_from)
1040 {
1041     Mpeg1Context *ctx = avctx->priv_data, *ctx_from = avctx_from->priv_data;
1042     MpegEncContext *s = &ctx->mpeg_enc_ctx, *s1 = &ctx_from->mpeg_enc_ctx;
1043     int err;
1044
1045     if (avctx == avctx_from || !ctx_from->mpeg_enc_ctx_allocated || !s1->context_initialized)
1046         return 0;
1047
1048     err = ff_mpeg_update_thread_context(avctx, avctx_from);
1049     if (err) return err;
1050
1051     if (!ctx->mpeg_enc_ctx_allocated)
1052         memcpy(s + 1, s1 + 1, sizeof(Mpeg1Context) - sizeof(MpegEncContext));
1053
1054     if (!(s->pict_type == AV_PICTURE_TYPE_B || s->low_delay))
1055         s->picture_number++;
1056
1057     return 0;
1058 }
1059
1060 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1061                                  const uint8_t *new_perm)
1062 {
1063     uint16_t temp_matrix[64];
1064     int i;
1065
1066     memcpy(temp_matrix, matrix, 64 * sizeof(uint16_t));
1067
1068     for (i = 0; i < 64; i++) {
1069         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1070     }
1071 }
1072
1073 static const enum AVPixelFormat pixfmt_xvmc_mpg2_420[] = {
1074     AV_PIX_FMT_XVMC_MPEG2_IDCT,
1075     AV_PIX_FMT_XVMC_MPEG2_MC,
1076     AV_PIX_FMT_NONE };
1077
1078 static const enum AVPixelFormat mpeg12_hwaccel_pixfmt_list_420[] = {
1079 #if CONFIG_MPEG2_DXVA2_HWACCEL
1080     AV_PIX_FMT_DXVA2_VLD,
1081 #endif
1082 #if CONFIG_MPEG2_VAAPI_HWACCEL
1083     AV_PIX_FMT_VAAPI_VLD,
1084 #endif
1085 #if CONFIG_MPEG1_VDPAU_HWACCEL | CONFIG_MPEG2_VDPAU_HWACCEL
1086     AV_PIX_FMT_VDPAU,
1087 #endif
1088     AV_PIX_FMT_YUV420P,
1089     AV_PIX_FMT_NONE
1090 };
1091
1092 static enum AVPixelFormat mpeg_get_pixelformat(AVCodecContext *avctx)
1093 {
1094     Mpeg1Context *s1 = avctx->priv_data;
1095     MpegEncContext *s = &s1->mpeg_enc_ctx;
1096
1097     if (avctx->xvmc_acceleration)
1098         return avctx->get_format(avctx, pixfmt_xvmc_mpg2_420);
1099     else if (avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU) {
1100         if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO)
1101             return AV_PIX_FMT_VDPAU_MPEG1;
1102         else
1103             return AV_PIX_FMT_VDPAU_MPEG2;
1104     } else {
1105         if (s->chroma_format <  2)
1106             return avctx->get_format(avctx, mpeg12_hwaccel_pixfmt_list_420);
1107         else if (s->chroma_format == 2)
1108             return AV_PIX_FMT_YUV422P;
1109         else
1110             return AV_PIX_FMT_YUV444P;
1111     }
1112 }
1113
1114 /* Call this function when we know all parameters.
1115  * It may be called in different places for MPEG-1 and MPEG-2. */
1116 static int mpeg_decode_postinit(AVCodecContext *avctx)
1117 {
1118     Mpeg1Context *s1 = avctx->priv_data;
1119     MpegEncContext *s = &s1->mpeg_enc_ctx;
1120     uint8_t old_permutation[64];
1121
1122     if ((s1->mpeg_enc_ctx_allocated == 0) ||
1123         avctx->coded_width  != s->width   ||
1124         avctx->coded_height != s->height  ||
1125         s1->save_width           != s->width                ||
1126         s1->save_height          != s->height               ||
1127         s1->save_aspect_info     != s->aspect_ratio_info    ||
1128         s1->save_progressive_seq != s->progressive_sequence ||
1129         0)
1130     {
1131
1132         if (s1->mpeg_enc_ctx_allocated) {
1133             ParseContext pc = s->parse_context;
1134             s->parse_context.buffer = 0;
1135             ff_MPV_common_end(s);
1136             s->parse_context = pc;
1137         }
1138
1139         if ((s->width == 0) || (s->height == 0))
1140             return -2;
1141
1142         avcodec_set_dimensions(avctx, s->width, s->height);
1143         avctx->bit_rate          = s->bit_rate;
1144         s1->save_aspect_info     = s->aspect_ratio_info;
1145         s1->save_width           = s->width;
1146         s1->save_height          = s->height;
1147         s1->save_progressive_seq = s->progressive_sequence;
1148
1149         /* low_delay may be forced, in this case we will have B-frames
1150          * that behave like P-frames. */
1151         avctx->has_b_frames = !s->low_delay;
1152
1153         if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1154             //MPEG-1 fps
1155             avctx->time_base.den = ff_mpeg12_frame_rate_tab[s->frame_rate_index].num;
1156             avctx->time_base.num = ff_mpeg12_frame_rate_tab[s->frame_rate_index].den;
1157             //MPEG-1 aspect
1158             avctx->sample_aspect_ratio = av_d2q(1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1159             avctx->ticks_per_frame=1;
1160         } else {//MPEG-2
1161         //MPEG-2 fps
1162             av_reduce(&s->avctx->time_base.den,
1163                       &s->avctx->time_base.num,
1164                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num*2,
1165                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1166                       1 << 30);
1167             avctx->ticks_per_frame = 2;
1168             //MPEG-2 aspect
1169             if (s->aspect_ratio_info > 1) {
1170                 AVRational dar =
1171                     av_mul_q(av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1172                                       (AVRational) {s1->pan_scan.width, s1->pan_scan.height}),
1173                              (AVRational) {s->width, s->height});
1174
1175                 // we ignore the spec here and guess a bit as reality does not match the spec, see for example
1176                 // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
1177                 // issue1613, 621, 562
1178                 if ((s1->pan_scan.width == 0) || (s1->pan_scan.height == 0) ||
1179                    (av_cmp_q(dar, (AVRational) {4, 3}) && av_cmp_q(dar, (AVRational) {16, 9}))) {
1180                     s->avctx->sample_aspect_ratio =
1181                         av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1182                                  (AVRational) {s->width, s->height});
1183                 } else {
1184                     s->avctx->sample_aspect_ratio =
1185                         av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1186                                  (AVRational) {s1->pan_scan.width, s1->pan_scan.height});
1187 //issue1613 4/3 16/9 -> 16/9
1188 //res_change_ffmpeg_aspect.ts 4/3 225/44 ->4/3
1189 //widescreen-issue562.mpg 4/3 16/9 -> 16/9
1190 //                    s->avctx->sample_aspect_ratio = av_mul_q(s->avctx->sample_aspect_ratio, (AVRational) {s->width, s->height});
1191                     av_dlog(avctx, "A %d/%d\n",
1192                             ff_mpeg2_aspect[s->aspect_ratio_info].num, ff_mpeg2_aspect[s->aspect_ratio_info].den);
1193                     av_dlog(avctx, "B %d/%d\n", s->avctx->sample_aspect_ratio.num,
1194                             s->avctx->sample_aspect_ratio.den);
1195                 }
1196             } else {
1197                 s->avctx->sample_aspect_ratio =
1198                     ff_mpeg2_aspect[s->aspect_ratio_info];
1199             }
1200         } // MPEG-2
1201
1202         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1203         avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
1204         // until then pix_fmt may be changed right after codec init
1205         if (avctx->pix_fmt == AV_PIX_FMT_XVMC_MPEG2_IDCT ||
1206             avctx->hwaccel                            ||
1207             s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)
1208             if (avctx->idct_algo == FF_IDCT_AUTO)
1209                 avctx->idct_algo = FF_IDCT_SIMPLE;
1210
1211         /* Quantization matrices may need reordering
1212          * if DCT permutation is changed. */
1213         memcpy(old_permutation, s->dsp.idct_permutation, 64 * sizeof(uint8_t));
1214
1215         if (ff_MPV_common_init(s) < 0)
1216             return -2;
1217
1218         quant_matrix_rebuild(s->intra_matrix,        old_permutation, s->dsp.idct_permutation);
1219         quant_matrix_rebuild(s->inter_matrix,        old_permutation, s->dsp.idct_permutation);
1220         quant_matrix_rebuild(s->chroma_intra_matrix, old_permutation, s->dsp.idct_permutation);
1221         quant_matrix_rebuild(s->chroma_inter_matrix, old_permutation, s->dsp.idct_permutation);
1222
1223         s1->mpeg_enc_ctx_allocated = 1;
1224     }
1225     return 0;
1226 }
1227
1228 static int mpeg1_decode_picture(AVCodecContext *avctx,
1229                                 const uint8_t *buf, int buf_size)
1230 {
1231     Mpeg1Context *s1 = avctx->priv_data;
1232     MpegEncContext *s = &s1->mpeg_enc_ctx;
1233     int ref, f_code, vbv_delay;
1234
1235     init_get_bits(&s->gb, buf, buf_size*8);
1236
1237     ref = get_bits(&s->gb, 10); /* temporal ref */
1238     s->pict_type = get_bits(&s->gb, 3);
1239     if (s->pict_type == 0 || s->pict_type > 3)
1240         return -1;
1241
1242     vbv_delay = get_bits(&s->gb, 16);
1243     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type == AV_PICTURE_TYPE_B) {
1244         s->full_pel[0] = get_bits1(&s->gb);
1245         f_code = get_bits(&s->gb, 3);
1246         if (f_code == 0 && (avctx->err_recognition & AV_EF_BITSTREAM))
1247             return -1;
1248         s->mpeg_f_code[0][0] = f_code;
1249         s->mpeg_f_code[0][1] = f_code;
1250     }
1251     if (s->pict_type == AV_PICTURE_TYPE_B) {
1252         s->full_pel[1] = get_bits1(&s->gb);
1253         f_code = get_bits(&s->gb, 3);
1254         if (f_code == 0 && (avctx->err_recognition & AV_EF_BITSTREAM))
1255             return -1;
1256         s->mpeg_f_code[1][0] = f_code;
1257         s->mpeg_f_code[1][1] = f_code;
1258     }
1259     s->current_picture.f.pict_type = s->pict_type;
1260     s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1261
1262     if (avctx->debug & FF_DEBUG_PICT_INFO)
1263         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1264
1265     s->y_dc_scale = 8;
1266     s->c_dc_scale = 8;
1267     return 0;
1268 }
1269
1270 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1271 {
1272     MpegEncContext *s= &s1->mpeg_enc_ctx;
1273     int horiz_size_ext, vert_size_ext;
1274     int bit_rate_ext;
1275
1276     skip_bits(&s->gb, 1); /* profile and level esc*/
1277     s->avctx->profile       = get_bits(&s->gb, 3);
1278     s->avctx->level         = get_bits(&s->gb, 4);
1279     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1280     s->chroma_format        = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1281     horiz_size_ext          = get_bits(&s->gb, 2);
1282     vert_size_ext           = get_bits(&s->gb, 2);
1283     s->width  |= (horiz_size_ext << 12);
1284     s->height |= (vert_size_ext  << 12);
1285     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1286     s->bit_rate += (bit_rate_ext << 18) * 400;
1287     skip_bits1(&s->gb); /* marker */
1288     s->avctx->rc_buffer_size += get_bits(&s->gb, 8) * 1024 * 16 << 10;
1289
1290     s->low_delay = get_bits1(&s->gb);
1291     if (s->flags & CODEC_FLAG_LOW_DELAY)
1292         s->low_delay = 1;
1293
1294     s1->frame_rate_ext.num = get_bits(&s->gb, 2) + 1;
1295     s1->frame_rate_ext.den = get_bits(&s->gb, 5) + 1;
1296
1297     av_dlog(s->avctx, "sequence extension\n");
1298     s->codec_id      = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
1299
1300     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1301         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1302                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1303
1304 }
1305
1306 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1307 {
1308     MpegEncContext *s = &s1->mpeg_enc_ctx;
1309     int color_description, w, h;
1310
1311     skip_bits(&s->gb, 3); /* video format */
1312     color_description = get_bits1(&s->gb);
1313     if (color_description) {
1314         s->avctx->color_primaries = get_bits(&s->gb, 8);
1315         s->avctx->color_trc       = get_bits(&s->gb, 8);
1316         s->avctx->colorspace      = get_bits(&s->gb, 8);
1317     }
1318     w = get_bits(&s->gb, 14);
1319     skip_bits(&s->gb, 1); //marker
1320     h = get_bits(&s->gb, 14);
1321     // remaining 3 bits are zero padding
1322
1323     s1->pan_scan.width  = 16 * w;
1324     s1->pan_scan.height = 16 * h;
1325
1326     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1327         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1328 }
1329
1330 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1331 {
1332     MpegEncContext *s = &s1->mpeg_enc_ctx;
1333     int i, nofco;
1334
1335     nofco = 1;
1336     if (s->progressive_sequence) {
1337         if (s->repeat_first_field) {
1338             nofco++;
1339             if (s->top_field_first)
1340                 nofco++;
1341         }
1342     } else {
1343         if (s->picture_structure == PICT_FRAME) {
1344             nofco++;
1345             if (s->repeat_first_field)
1346                 nofco++;
1347         }
1348     }
1349     for (i = 0; i < nofco; i++) {
1350         s1->pan_scan.position[i][0] = get_sbits(&s->gb, 16);
1351         skip_bits(&s->gb, 1); // marker
1352         s1->pan_scan.position[i][1] = get_sbits(&s->gb, 16);
1353         skip_bits(&s->gb, 1); // marker
1354     }
1355
1356     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1357         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1358                s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1359                s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1360                s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]);
1361 }
1362
1363 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64], uint16_t matrix1[64], int intra)
1364 {
1365     int i;
1366
1367     for (i = 0; i < 64; i++) {
1368         int j = s->dsp.idct_permutation[ff_zigzag_direct[i]];
1369         int v = get_bits(&s->gb, 8);
1370         if (v == 0) {
1371             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1372             return -1;
1373         }
1374         if (intra && i == 0 && v != 8) {
1375             av_log(s->avctx, AV_LOG_ERROR, "intra matrix invalid, ignoring\n");
1376             v = 8; // needed by pink.mpg / issue1046
1377         }
1378         matrix0[j] = v;
1379         if (matrix1)
1380             matrix1[j] = v;
1381     }
1382     return 0;
1383 }
1384
1385 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1386 {
1387     av_dlog(s->avctx, "matrix extension\n");
1388
1389     if (get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1390     if (get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1391     if (get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, NULL           , 1);
1392     if (get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, NULL           , 0);
1393 }
1394
1395 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1396 {
1397     MpegEncContext *s = &s1->mpeg_enc_ctx;
1398
1399     s->full_pel[0] = s->full_pel[1] = 0;
1400     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1401     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1402     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1403     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1404     if (!s->pict_type && s1->mpeg_enc_ctx_allocated) {
1405         av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
1406         if (s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1] == 15) {
1407             if (s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1408                 s->pict_type = AV_PICTURE_TYPE_I;
1409             else
1410                 s->pict_type = AV_PICTURE_TYPE_P;
1411         } else
1412             s->pict_type = AV_PICTURE_TYPE_B;
1413         s->current_picture.f.pict_type = s->pict_type;
1414         s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1415     }
1416     s->intra_dc_precision         = get_bits(&s->gb, 2);
1417     s->picture_structure          = get_bits(&s->gb, 2);
1418     s->top_field_first            = get_bits1(&s->gb);
1419     s->frame_pred_frame_dct       = get_bits1(&s->gb);
1420     s->concealment_motion_vectors = get_bits1(&s->gb);
1421     s->q_scale_type               = get_bits1(&s->gb);
1422     s->intra_vlc_format           = get_bits1(&s->gb);
1423     s->alternate_scan             = get_bits1(&s->gb);
1424     s->repeat_first_field         = get_bits1(&s->gb);
1425     s->chroma_420_type            = get_bits1(&s->gb);
1426     s->progressive_frame          = get_bits1(&s->gb);
1427
1428     if (s->progressive_sequence && !s->progressive_frame) {
1429         s->progressive_frame = 1;
1430         av_log(s->avctx, AV_LOG_ERROR, "interlaced frame in progressive sequence, ignoring\n");
1431     }
1432
1433     if (s->picture_structure == 0 || (s->progressive_frame && s->picture_structure != PICT_FRAME)) {
1434         av_log(s->avctx, AV_LOG_ERROR, "picture_structure %d invalid, ignoring\n", s->picture_structure);
1435         s->picture_structure = PICT_FRAME;
1436     }
1437
1438     if (s->progressive_sequence && !s->frame_pred_frame_dct) {
1439         av_log(s->avctx, AV_LOG_WARNING, "invalid frame_pred_frame_dct\n");
1440     }
1441
1442     if (s->picture_structure == PICT_FRAME) {
1443         s->first_field = 0;
1444         s->v_edge_pos  = 16 * s->mb_height;
1445     } else {
1446         s->first_field ^= 1;
1447         s->v_edge_pos   = 8 * s->mb_height;
1448         memset(s->mbskip_table, 0, s->mb_stride * s->mb_height);
1449     }
1450
1451     if (s->alternate_scan) {
1452         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
1453         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
1454     } else {
1455         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
1456         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
1457     }
1458
1459     /* composite display not parsed */
1460     av_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1461     av_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
1462     av_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
1463     av_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1464     av_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1465     av_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1466     av_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1467     av_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1468     av_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1469 }
1470
1471 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size)
1472 {
1473     AVCodecContext *avctx = s->avctx;
1474     Mpeg1Context *s1 = (Mpeg1Context*)s;
1475
1476     /* start frame decoding */
1477     if (s->first_field || s->picture_structure == PICT_FRAME) {
1478         AVFrameSideData *pan_scan;
1479
1480         if (ff_MPV_frame_start(s, avctx) < 0)
1481             return -1;
1482
1483         ff_mpeg_er_frame_start(s);
1484
1485         /* first check if we must repeat the frame */
1486         s->current_picture_ptr->f.repeat_pict = 0;
1487         if (s->repeat_first_field) {
1488             if (s->progressive_sequence) {
1489                 if (s->top_field_first)
1490                     s->current_picture_ptr->f.repeat_pict = 4;
1491                 else
1492                     s->current_picture_ptr->f.repeat_pict = 2;
1493             } else if (s->progressive_frame) {
1494                 s->current_picture_ptr->f.repeat_pict = 1;
1495             }
1496         }
1497
1498         pan_scan = av_frame_new_side_data(&s->current_picture_ptr->f,
1499                                           AV_FRAME_DATA_PANSCAN,
1500                                           sizeof(s1->pan_scan));
1501         if (!pan_scan)
1502             return AVERROR(ENOMEM);
1503         memcpy(pan_scan->data, &s1->pan_scan, sizeof(s1->pan_scan));
1504
1505         if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_FRAME))
1506             ff_thread_finish_setup(avctx);
1507     } else { // second field
1508         int i;
1509
1510         if (!s->current_picture_ptr) {
1511             av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1512             return -1;
1513         }
1514
1515         if (s->avctx->hwaccel &&
1516             (s->avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
1517             if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
1518                 av_log(avctx, AV_LOG_ERROR, "hardware accelerator failed to decode first field\n");
1519         }
1520
1521         for (i = 0; i < 4; i++) {
1522             s->current_picture.f.data[i] = s->current_picture_ptr->f.data[i];
1523             if (s->picture_structure == PICT_BOTTOM_FIELD) {
1524                 s->current_picture.f.data[i] += s->current_picture_ptr->f.linesize[i];
1525             }
1526         }
1527     }
1528
1529     if (avctx->hwaccel) {
1530         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
1531             return -1;
1532     }
1533
1534 // MPV_frame_start will call this function too,
1535 // but we need to call it on every field
1536     if (CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1537         if (ff_xvmc_field_start(s, avctx) < 0)
1538             return -1;
1539
1540     return 0;
1541 }
1542
1543 #define DECODE_SLICE_ERROR -1
1544 #define DECODE_SLICE_OK     0
1545
1546 /**
1547  * Decode a slice.
1548  * MpegEncContext.mb_y must be set to the MB row from the startcode.
1549  * @return DECODE_SLICE_ERROR if the slice is damaged,
1550  *         DECODE_SLICE_OK if this slice is OK
1551  */
1552 static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
1553                              const uint8_t **buf, int buf_size)
1554 {
1555     AVCodecContext *avctx = s->avctx;
1556     const int field_pic   = s->picture_structure != PICT_FRAME;
1557
1558     s->resync_mb_x =
1559     s->resync_mb_y = -1;
1560
1561     assert(mb_y < s->mb_height);
1562
1563     init_get_bits(&s->gb, *buf, buf_size * 8);
1564
1565     ff_mpeg1_clean_buffers(s);
1566     s->interlaced_dct = 0;
1567
1568     s->qscale = get_qscale(s);
1569
1570     if (s->qscale == 0) {
1571         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1572         return -1;
1573     }
1574
1575     /* extra slice info */
1576     while (get_bits1(&s->gb) != 0) {
1577         skip_bits(&s->gb, 8);
1578     }
1579
1580     s->mb_x = 0;
1581
1582     if (mb_y == 0 && s->codec_tag == AV_RL32("SLIF")) {
1583         skip_bits1(&s->gb);
1584     } else {
1585         while (get_bits_left(&s->gb) > 0) {
1586             int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1587                                 MBINCR_VLC_BITS, 2);
1588             if (code < 0) {
1589                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1590                 return -1;
1591             }
1592             if (code >= 33) {
1593                 if (code == 33) {
1594                     s->mb_x += 33;
1595                 }
1596                 /* otherwise, stuffing, nothing to do */
1597             } else {
1598                 s->mb_x += code;
1599                 break;
1600             }
1601         }
1602     }
1603
1604     if (s->mb_x >= (unsigned)s->mb_width) {
1605         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1606         return -1;
1607     }
1608
1609     if (avctx->hwaccel) {
1610         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1611         int start_code = -1;
1612         buf_end = avpriv_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1613         if (buf_end < *buf + buf_size)
1614             buf_end -= 4;
1615         s->mb_y = mb_y;
1616         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1617             return DECODE_SLICE_ERROR;
1618         *buf = buf_end;
1619         return DECODE_SLICE_OK;
1620     }
1621
1622     s->resync_mb_x = s->mb_x;
1623     s->resync_mb_y = s->mb_y = mb_y;
1624     s->mb_skip_run = 0;
1625     ff_init_block_index(s);
1626
1627     if (s->mb_y == 0 && s->mb_x == 0 && (s->first_field || s->picture_structure == PICT_FRAME)) {
1628         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
1629              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",
1630                     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],
1631                     s->pict_type == AV_PICTURE_TYPE_I ? "I" : (s->pict_type == AV_PICTURE_TYPE_P ? "P" : (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
1632                     s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1633                     s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1634                     s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1635         }
1636     }
1637
1638     for (;;) {
1639         // If 1, we memcpy blocks in xvmcvideo.
1640         if (CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1)
1641             ff_xvmc_init_block(s); // set s->block
1642
1643         if (mpeg_decode_mb(s, s->block) < 0)
1644             return -1;
1645
1646         if (s->current_picture.motion_val[0] && !s->encoding) { // note motion_val is normally NULL unless we want to extract the MVs
1647             const int wrap = s->b8_stride;
1648             int xy         = s->mb_x * 2 + s->mb_y * 2 * wrap;
1649             int b8_xy      = 4 * (s->mb_x + s->mb_y * s->mb_stride);
1650             int motion_x, motion_y, dir, i;
1651
1652             for (i = 0; i < 2; i++) {
1653                 for (dir = 0; dir < 2; dir++) {
1654                     if (s->mb_intra || (dir == 1 && s->pict_type != AV_PICTURE_TYPE_B)) {
1655                         motion_x = motion_y = 0;
1656                     } else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)) {
1657                         motion_x = s->mv[dir][0][0];
1658                         motion_y = s->mv[dir][0][1];
1659                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1660                         motion_x = s->mv[dir][i][0];
1661                         motion_y = s->mv[dir][i][1];
1662                     }
1663
1664                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1665                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1666                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1667                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1668                     s->current_picture.ref_index [dir][b8_xy    ] =
1669                     s->current_picture.ref_index [dir][b8_xy + 1] = s->field_select[dir][i];
1670                     assert(s->field_select[dir][i] == 0 || s->field_select[dir][i] == 1);
1671                 }
1672                 xy += wrap;
1673                 b8_xy +=2;
1674             }
1675         }
1676
1677         s->dest[0] += 16;
1678         s->dest[1] += 16 >> s->chroma_x_shift;
1679         s->dest[2] += 16 >> s->chroma_x_shift;
1680
1681         ff_MPV_decode_mb(s, s->block);
1682
1683         if (++s->mb_x >= s->mb_width) {
1684             const int mb_size = 16;
1685
1686             ff_mpeg_draw_horiz_band(s, mb_size*(s->mb_y >> field_pic), mb_size);
1687             ff_MPV_report_decode_progress(s);
1688
1689             s->mb_x = 0;
1690             s->mb_y += 1 << field_pic;
1691
1692             if (s->mb_y >= s->mb_height) {
1693                 int left   = get_bits_left(&s->gb);
1694                 int is_d10 = s->chroma_format == 2 && s->pict_type == AV_PICTURE_TYPE_I && avctx->profile == 0 && avctx->level == 5
1695                              && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1696                              && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1697
1698                 if (left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1699                     || ((avctx->err_recognition & AV_EF_BUFFER) && left > 8)) {
1700                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1701                     return -1;
1702                 } else
1703                     goto eos;
1704             }
1705
1706             ff_init_block_index(s);
1707         }
1708
1709         /* skip mb handling */
1710         if (s->mb_skip_run == -1) {
1711             /* read increment again */
1712             s->mb_skip_run = 0;
1713             for (;;) {
1714                 int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1715                                     MBINCR_VLC_BITS, 2);
1716                 if (code < 0) {
1717                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1718                     return -1;
1719                 }
1720                 if (code >= 33) {
1721                     if (code == 33) {
1722                         s->mb_skip_run += 33;
1723                     } else if (code == 35) {
1724                         if (s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0) {
1725                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1726                             return -1;
1727                         }
1728                         goto eos; /* end of slice */
1729                     }
1730                     /* otherwise, stuffing, nothing to do */
1731                 } else {
1732                     s->mb_skip_run += code;
1733                     break;
1734                 }
1735             }
1736             if (s->mb_skip_run) {
1737                 int i;
1738                 if (s->pict_type == AV_PICTURE_TYPE_I) {
1739                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1740                     return -1;
1741                 }
1742
1743                 /* skip mb */
1744                 s->mb_intra = 0;
1745                 for (i = 0; i < 12; i++)
1746                     s->block_last_index[i] = -1;
1747                 if (s->picture_structure == PICT_FRAME)
1748                     s->mv_type = MV_TYPE_16X16;
1749                 else
1750                     s->mv_type = MV_TYPE_FIELD;
1751                 if (s->pict_type == AV_PICTURE_TYPE_P) {
1752                     /* if P type, zero motion vector is implied */
1753                     s->mv_dir             = MV_DIR_FORWARD;
1754                     s->mv[0][0][0]        = s->mv[0][0][1]      = 0;
1755                     s->last_mv[0][0][0]   = s->last_mv[0][0][1] = 0;
1756                     s->last_mv[0][1][0]   = s->last_mv[0][1][1] = 0;
1757                     s->field_select[0][0] = (s->picture_structure - 1) & 1;
1758                 } else {
1759                     /* if B type, reuse previous vectors and directions */
1760                     s->mv[0][0][0] = s->last_mv[0][0][0];
1761                     s->mv[0][0][1] = s->last_mv[0][0][1];
1762                     s->mv[1][0][0] = s->last_mv[1][0][0];
1763                     s->mv[1][0][1] = s->last_mv[1][0][1];
1764                 }
1765             }
1766         }
1767     }
1768 eos: // end of slice
1769     *buf += (get_bits_count(&s->gb)-1)/8;
1770     av_dlog(s, "y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1771     return 0;
1772 }
1773
1774 static int slice_decode_thread(AVCodecContext *c, void *arg)
1775 {
1776     MpegEncContext *s   = *(void**)arg;
1777     const uint8_t *buf  = s->gb.buffer;
1778     int mb_y            = s->start_mb_y;
1779     const int field_pic = s->picture_structure != PICT_FRAME;
1780
1781     s->er.error_count = (3 * (s->end_mb_y - s->start_mb_y) * s->mb_width) >> field_pic;
1782
1783     for (;;) {
1784         uint32_t start_code;
1785         int ret;
1786
1787         ret = mpeg_decode_slice(s, mb_y, &buf, s->gb.buffer_end - buf);
1788         emms_c();
1789         av_dlog(c, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1790                 ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y,
1791                 s->start_mb_y, s->end_mb_y, s->er.error_count);
1792         if (ret < 0) {
1793             if (c->err_recognition & AV_EF_EXPLODE)
1794                 return ret;
1795             if (s->resync_mb_x >= 0 && s->resync_mb_y >= 0)
1796                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
1797         } else {
1798             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_AC_END | ER_DC_END | ER_MV_END);
1799         }
1800
1801         if (s->mb_y == s->end_mb_y)
1802             return 0;
1803
1804         start_code = -1;
1805         buf = avpriv_find_start_code(buf, s->gb.buffer_end, &start_code);
1806         mb_y= (start_code - SLICE_MIN_START_CODE) << field_pic;
1807         if (s->picture_structure == PICT_BOTTOM_FIELD)
1808             mb_y++;
1809         if (mb_y < 0 || mb_y >= s->end_mb_y)
1810             return -1;
1811     }
1812 }
1813
1814 /**
1815  * Handle slice ends.
1816  * @return 1 if it seems to be the last slice
1817  */
1818 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1819 {
1820     Mpeg1Context *s1 = avctx->priv_data;
1821     MpegEncContext *s = &s1->mpeg_enc_ctx;
1822
1823     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1824         return 0;
1825
1826     if (s->avctx->hwaccel) {
1827         if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
1828             av_log(avctx, AV_LOG_ERROR, "hardware accelerator failed to decode picture\n");
1829     }
1830
1831     if (CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1832         ff_xvmc_field_end(s);
1833
1834     /* end of slice reached */
1835     if (/*s->mb_y << field_pic == s->mb_height &&*/ !s->first_field) {
1836         /* end of image */
1837
1838         ff_er_frame_end(&s->er);
1839
1840         ff_MPV_frame_end(s);
1841
1842         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
1843             int ret = av_frame_ref(pict, &s->current_picture_ptr->f);
1844             if (ret < 0)
1845                 return ret;
1846             ff_print_debug_info(s, s->current_picture_ptr);
1847         } else {
1848             if (avctx->active_thread_type & FF_THREAD_FRAME)
1849                 s->picture_number++;
1850             /* latency of 1 frame for I- and P-frames */
1851             /* XXX: use another variable than picture_number */
1852             if (s->last_picture_ptr != NULL) {
1853                 int ret = av_frame_ref(pict, &s->last_picture_ptr->f);
1854                 if (ret < 0)
1855                     return ret;
1856                 ff_print_debug_info(s, s->last_picture_ptr);
1857             }
1858         }
1859
1860         return 1;
1861     } else {
1862         return 0;
1863     }
1864 }
1865
1866 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1867                                  const uint8_t *buf, int buf_size)
1868 {
1869     Mpeg1Context *s1 = avctx->priv_data;
1870     MpegEncContext *s = &s1->mpeg_enc_ctx;
1871     int width, height;
1872     int i, v, j;
1873
1874     init_get_bits(&s->gb, buf, buf_size*8);
1875
1876     width  = get_bits(&s->gb, 12);
1877     height = get_bits(&s->gb, 12);
1878     if (width == 0 || height == 0) {
1879         av_log(avctx, AV_LOG_WARNING, "Invalid horizontal or vertical size "
1880                "value.\n");
1881         if (avctx->err_recognition & AV_EF_BITSTREAM)
1882             return AVERROR_INVALIDDATA;
1883     }
1884     s->aspect_ratio_info = get_bits(&s->gb, 4);
1885     if (s->aspect_ratio_info == 0) {
1886         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
1887         if (avctx->err_recognition & AV_EF_BITSTREAM)
1888             return -1;
1889     }
1890     s->frame_rate_index = get_bits(&s->gb, 4);
1891     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
1892         return -1;
1893     s->bit_rate = get_bits(&s->gb, 18) * 400;
1894     if (get_bits1(&s->gb) == 0) /* marker */
1895         return -1;
1896     s->width  = width;
1897     s->height = height;
1898
1899     s->avctx->rc_buffer_size = get_bits(&s->gb, 10) * 1024 * 16;
1900     skip_bits(&s->gb, 1);
1901
1902     /* get matrix */
1903     if (get_bits1(&s->gb)) {
1904         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1905     } else {
1906         for (i = 0; i < 64; i++) {
1907             j = s->dsp.idct_permutation[i];
1908             v = ff_mpeg1_default_intra_matrix[i];
1909             s->intra_matrix[j]        = v;
1910             s->chroma_intra_matrix[j] = v;
1911         }
1912     }
1913     if (get_bits1(&s->gb)) {
1914         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1915     } else {
1916         for (i = 0; i < 64; i++) {
1917             int j = s->dsp.idct_permutation[i];
1918             v = ff_mpeg1_default_non_intra_matrix[i];
1919             s->inter_matrix[j]        = v;
1920             s->chroma_inter_matrix[j] = v;
1921         }
1922     }
1923
1924     if (show_bits(&s->gb, 23) != 0) {
1925         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
1926         return -1;
1927     }
1928
1929     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
1930     s->progressive_sequence = 1;
1931     s->progressive_frame    = 1;
1932     s->picture_structure    = PICT_FRAME;
1933     s->frame_pred_frame_dct = 1;
1934     s->chroma_format        = 1;
1935     s->codec_id             = s->avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
1936     s->out_format           = FMT_MPEG1;
1937     s->swap_uv              = 0; // AFAIK VCR2 does not have SEQ_HEADER
1938     if (s->flags & CODEC_FLAG_LOW_DELAY)
1939         s->low_delay = 1;
1940
1941     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1942         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
1943                s->avctx->rc_buffer_size, s->bit_rate);
1944
1945     return 0;
1946 }
1947
1948 static int vcr2_init_sequence(AVCodecContext *avctx)
1949 {
1950     Mpeg1Context *s1 = avctx->priv_data;
1951     MpegEncContext *s = &s1->mpeg_enc_ctx;
1952     int i, v;
1953
1954     /* start new MPEG-1 context decoding */
1955     s->out_format = FMT_MPEG1;
1956     if (s1->mpeg_enc_ctx_allocated) {
1957         ff_MPV_common_end(s);
1958     }
1959     s->width  = avctx->coded_width;
1960     s->height = avctx->coded_height;
1961     avctx->has_b_frames = 0; // true?
1962     s->low_delay = 1;
1963
1964     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1965     avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
1966
1967     if (avctx->pix_fmt == AV_PIX_FMT_XVMC_MPEG2_IDCT || avctx->hwaccel ||
1968         s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)
1969         if (avctx->idct_algo == FF_IDCT_AUTO)
1970             avctx->idct_algo = FF_IDCT_SIMPLE;
1971
1972     if (ff_MPV_common_init(s) < 0)
1973         return -1;
1974     exchange_uv(s); // common init reset pblocks, so we swap them here
1975     s->swap_uv = 1; // in case of xvmc we need to swap uv for each MB
1976     s1->mpeg_enc_ctx_allocated = 1;
1977
1978     for (i = 0; i < 64; i++) {
1979         int j = s->dsp.idct_permutation[i];
1980         v = ff_mpeg1_default_intra_matrix[i];
1981         s->intra_matrix[j]        = v;
1982         s->chroma_intra_matrix[j] = v;
1983
1984         v = ff_mpeg1_default_non_intra_matrix[i];
1985         s->inter_matrix[j]        = v;
1986         s->chroma_inter_matrix[j] = v;
1987     }
1988
1989     s->progressive_sequence  = 1;
1990     s->progressive_frame     = 1;
1991     s->picture_structure     = PICT_FRAME;
1992     s->frame_pred_frame_dct  = 1;
1993     s->chroma_format         = 1;
1994     s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
1995     s1->save_width           = s->width;
1996     s1->save_height          = s->height;
1997     s1->save_progressive_seq = s->progressive_sequence;
1998     return 0;
1999 }
2000
2001
2002 static void mpeg_decode_user_data(AVCodecContext *avctx,
2003                                   const uint8_t *p, int buf_size)
2004 {
2005     const uint8_t *buf_end = p + buf_size;
2006
2007     /* we parse the DTG active format information */
2008     if (buf_end - p >= 5 &&
2009         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2010         int flags = p[4];
2011         p += 5;
2012         if (flags & 0x80) {
2013             /* skip event id */
2014             p += 2;
2015         }
2016         if (flags & 0x40) {
2017             if (buf_end - p < 1)
2018                 return;
2019             avctx->dtg_active_format = p[0] & 0x0f;
2020         }
2021     }
2022 }
2023
2024 static void mpeg_decode_gop(AVCodecContext *avctx,
2025                             const uint8_t *buf, int buf_size)
2026 {
2027     Mpeg1Context *s1  = avctx->priv_data;
2028     MpegEncContext *s = &s1->mpeg_enc_ctx;
2029
2030     int time_code_hours, time_code_minutes;
2031     int time_code_seconds, time_code_pictures;
2032     int broken_link;
2033
2034     init_get_bits(&s->gb, buf, buf_size*8);
2035
2036     skip_bits1(&s->gb); /* drop_frame_flag */
2037
2038     time_code_hours   = get_bits(&s->gb, 5);
2039     time_code_minutes = get_bits(&s->gb, 6);
2040     skip_bits1(&s->gb); // marker bit
2041     time_code_seconds  = get_bits(&s->gb, 6);
2042     time_code_pictures = get_bits(&s->gb, 6);
2043
2044     s1->closed_gop = get_bits1(&s->gb);
2045     /*broken_link indicate that after editing the
2046       reference frames of the first B-Frames after GOP I-Frame
2047       are missing (open gop)*/
2048     broken_link = get_bits1(&s->gb);
2049
2050     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2051         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2052                time_code_hours, time_code_minutes, time_code_seconds,
2053                time_code_pictures, s1->closed_gop, broken_link);
2054 }
2055
2056 static int decode_chunks(AVCodecContext *avctx,
2057                          AVFrame *picture, int *got_output,
2058                          const uint8_t *buf, int buf_size)
2059 {
2060     Mpeg1Context *s = avctx->priv_data;
2061     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2062     const uint8_t *buf_ptr = buf;
2063     const uint8_t *buf_end = buf + buf_size;
2064     int ret, input_size;
2065     int last_code = 0;
2066
2067     for (;;) {
2068         /* find next start code */
2069         uint32_t start_code = -1;
2070         buf_ptr = avpriv_find_start_code(buf_ptr, buf_end, &start_code);
2071         if (start_code > 0x1ff) {
2072             if (s2->pict_type != AV_PICTURE_TYPE_B || avctx->skip_frame <= AVDISCARD_DEFAULT) {
2073                 if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE)) {
2074                     int i;
2075
2076                     avctx->execute(avctx, slice_decode_thread,  &s2->thread_context[0], NULL, s->slice_count, sizeof(void*));
2077                     for (i = 0; i < s->slice_count; i++)
2078                         s2->er.error_count += s2->thread_context[i]->er.error_count;
2079                 }
2080
2081                 if ((CONFIG_MPEG_VDPAU_DECODER || CONFIG_MPEG1_VDPAU_DECODER)
2082                     && avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)
2083                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2084
2085                 ret = slice_end(avctx, picture);
2086                 if (ret < 0)
2087                     return ret;
2088                 else if (ret) {
2089                     if (s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2090                         *got_output = 1;
2091                 }
2092             }
2093             s2->pict_type = 0;
2094             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2095         }
2096
2097         input_size = buf_end - buf_ptr;
2098
2099         if (avctx->debug & FF_DEBUG_STARTCODE) {
2100             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2101         }
2102
2103         /* prepare data for next start code */
2104         switch (start_code) {
2105         case SEQ_START_CODE:
2106             if (last_code == 0) {
2107                 mpeg1_decode_sequence(avctx, buf_ptr, input_size);
2108                 s->sync=1;
2109             } else {
2110                 av_log(avctx, AV_LOG_ERROR, "ignoring SEQ_START_CODE after %X\n", last_code);
2111                 if (avctx->err_recognition & AV_EF_EXPLODE)
2112                     return AVERROR_INVALIDDATA;
2113             }
2114             break;
2115
2116         case PICTURE_START_CODE:
2117             if (s2->width <= 0 || s2->height <= 0) {
2118                 av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d.\n",
2119                        s2->width, s2->height);
2120                 return AVERROR_INVALIDDATA;
2121             }
2122
2123             if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) && s->slice_count) {
2124                 int i;
2125
2126                 avctx->execute(avctx, slice_decode_thread,
2127                                s2->thread_context, NULL,
2128                                s->slice_count, sizeof(void*));
2129                 for (i = 0; i < s->slice_count; i++)
2130                     s2->er.error_count += s2->thread_context[i]->er.error_count;
2131                 s->slice_count = 0;
2132             }
2133             if (last_code == 0 || last_code == SLICE_MIN_START_CODE) {
2134                 ret = mpeg_decode_postinit(avctx);
2135                 if (ret < 0) {
2136                     av_log(avctx, AV_LOG_ERROR, "mpeg_decode_postinit() failure\n");
2137                     return ret;
2138                 }
2139
2140                 /* we have a complete image: we try to decompress it */
2141                 if (mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0)
2142                     s2->pict_type = 0;
2143                 s2->first_slice = 1;
2144                 last_code = PICTURE_START_CODE;
2145             } else {
2146                 av_log(avctx, AV_LOG_ERROR, "ignoring pic after %X\n", last_code);
2147                 if (avctx->err_recognition & AV_EF_EXPLODE)
2148                     return AVERROR_INVALIDDATA;
2149             }
2150             break;
2151         case EXT_START_CODE:
2152             init_get_bits(&s2->gb, buf_ptr, input_size*8);
2153
2154             switch (get_bits(&s2->gb, 4)) {
2155             case 0x1:
2156                 if (last_code == 0) {
2157                 mpeg_decode_sequence_extension(s);
2158                 } else {
2159                     av_log(avctx, AV_LOG_ERROR, "ignoring seq ext after %X\n", last_code);
2160                     if (avctx->err_recognition & AV_EF_EXPLODE)
2161                         return AVERROR_INVALIDDATA;
2162                 }
2163                 break;
2164             case 0x2:
2165                 mpeg_decode_sequence_display_extension(s);
2166                 break;
2167             case 0x3:
2168                 mpeg_decode_quant_matrix_extension(s2);
2169                 break;
2170             case 0x7:
2171                 mpeg_decode_picture_display_extension(s);
2172                 break;
2173             case 0x8:
2174                 if (last_code == PICTURE_START_CODE) {
2175                     mpeg_decode_picture_coding_extension(s);
2176                 } else {
2177                     av_log(avctx, AV_LOG_ERROR, "ignoring pic cod ext after %X\n", last_code);
2178                     if (avctx->err_recognition & AV_EF_EXPLODE)
2179                         return AVERROR_INVALIDDATA;
2180                 }
2181                 break;
2182             }
2183             break;
2184         case USER_START_CODE:
2185             mpeg_decode_user_data(avctx, buf_ptr, input_size);
2186             break;
2187         case GOP_START_CODE:
2188             if (last_code == 0) {
2189                 s2->first_field=0;
2190                 mpeg_decode_gop(avctx, buf_ptr, input_size);
2191                 s->sync=1;
2192             } else {
2193                 av_log(avctx, AV_LOG_ERROR, "ignoring GOP_START_CODE after %X\n", last_code);
2194                 if (avctx->err_recognition & AV_EF_EXPLODE)
2195                     return AVERROR_INVALIDDATA;
2196             }
2197             break;
2198         default:
2199             if (start_code >= SLICE_MIN_START_CODE &&
2200                 start_code <= SLICE_MAX_START_CODE && last_code != 0) {
2201                 const int field_pic = s2->picture_structure != PICT_FRAME;
2202                 int mb_y = (start_code - SLICE_MIN_START_CODE) << field_pic;
2203                 last_code = SLICE_MIN_START_CODE;
2204
2205                 if (s2->picture_structure == PICT_BOTTOM_FIELD)
2206                     mb_y++;
2207
2208                 if (mb_y >= s2->mb_height) {
2209                     av_log(s2->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2210                     return -1;
2211                 }
2212
2213                 if (s2->last_picture_ptr == NULL) {
2214                 /* Skip B-frames if we do not have reference frames and gop is not closed */
2215                     if (s2->pict_type == AV_PICTURE_TYPE_B) {
2216                         if (!s->closed_gop)
2217                             break;
2218                     }
2219                 }
2220                 if (s2->pict_type == AV_PICTURE_TYPE_I)
2221                     s->sync=1;
2222                 if (s2->next_picture_ptr == NULL) {
2223                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2224                     if (s2->pict_type == AV_PICTURE_TYPE_P && !s->sync) break;
2225                 }
2226                 if ((avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type == AV_PICTURE_TYPE_B) ||
2227                     (avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type != AV_PICTURE_TYPE_I) ||
2228                      avctx->skip_frame >= AVDISCARD_ALL)
2229                     break;
2230
2231                 if (!s->mpeg_enc_ctx_allocated)
2232                     break;
2233
2234                 if (s2->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
2235                     if (mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2236                         break;
2237                 }
2238
2239                 if (!s2->pict_type) {
2240                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2241                     if (avctx->err_recognition & AV_EF_EXPLODE)
2242                         return AVERROR_INVALIDDATA;
2243                     break;
2244                 }
2245
2246                 if (s2->first_slice) {
2247                     s2->first_slice = 0;
2248                     if (mpeg_field_start(s2, buf, buf_size) < 0)
2249                         return -1;
2250                 }
2251                 if (!s2->current_picture_ptr) {
2252                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2253                     return AVERROR_INVALIDDATA;
2254                 }
2255
2256                 if (avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU) {
2257                     s->slice_count++;
2258                     break;
2259                 }
2260
2261                 if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE)) {
2262                     int threshold = (s2->mb_height * s->slice_count +
2263                                      s2->slice_context_count / 2) /
2264                                     s2->slice_context_count;
2265                     if (threshold <= mb_y) {
2266                         MpegEncContext *thread_context = s2->thread_context[s->slice_count];
2267
2268                         thread_context->start_mb_y = mb_y;
2269                         thread_context->end_mb_y   = s2->mb_height;
2270                         if (s->slice_count) {
2271                             s2->thread_context[s->slice_count-1]->end_mb_y = mb_y;
2272                             ret = ff_update_duplicate_context(thread_context,
2273                                                               s2);
2274                             if (ret < 0)
2275                                 return ret;
2276                         }
2277                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2278                         s->slice_count++;
2279                     }
2280                     buf_ptr += 2; // FIXME add minimum number of bytes per slice
2281                 } else {
2282                     ret = mpeg_decode_slice(s2, mb_y, &buf_ptr, input_size);
2283                     emms_c();
2284
2285                     if (ret < 0) {
2286                         if (avctx->err_recognition & AV_EF_EXPLODE)
2287                             return ret;
2288                         if (s2->resync_mb_x >= 0 && s2->resync_mb_y >= 0)
2289                             ff_er_add_slice(&s2->er, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x, s2->mb_y, ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2290                     } else {
2291                         ff_er_add_slice(&s2->er, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x-1, s2->mb_y, ER_AC_END | ER_DC_END | ER_MV_END);
2292                     }
2293                 }
2294             }
2295             break;
2296         }
2297     }
2298 }
2299
2300 static int mpeg_decode_frame(AVCodecContext *avctx,
2301                              void *data, int *got_output,
2302                              AVPacket *avpkt)
2303 {
2304     const uint8_t *buf = avpkt->data;
2305     int buf_size = avpkt->size;
2306     Mpeg1Context *s = avctx->priv_data;
2307     AVFrame *picture = data;
2308     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2309     av_dlog(avctx, "fill_buffer\n");
2310
2311     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2312         /* special case for last picture */
2313         if (s2->low_delay == 0 && s2->next_picture_ptr) {
2314             int ret = av_frame_ref(picture, &s2->next_picture_ptr->f);
2315             if (ret < 0)
2316                 return ret;
2317
2318             s2->next_picture_ptr = NULL;
2319
2320             *got_output = 1;
2321         }
2322         return buf_size;
2323     }
2324
2325     if (s2->flags & CODEC_FLAG_TRUNCATED) {
2326         int next = ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size, NULL);
2327
2328         if (ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0)
2329             return buf_size;
2330     }
2331
2332     if (s->mpeg_enc_ctx_allocated == 0 && avctx->codec_tag == AV_RL32("VCR2"))
2333         vcr2_init_sequence(avctx);
2334
2335     s->slice_count = 0;
2336
2337     if (avctx->extradata && !s->extradata_decoded) {
2338         int ret = decode_chunks(avctx, picture, got_output, avctx->extradata, avctx->extradata_size);
2339         s->extradata_decoded = 1;
2340         if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
2341             return ret;
2342     }
2343
2344     return decode_chunks(avctx, picture, got_output, buf, buf_size);
2345 }
2346
2347
2348 static void flush(AVCodecContext *avctx)
2349 {
2350     Mpeg1Context *s = avctx->priv_data;
2351
2352     s->sync=0;
2353     s->closed_gop = 0;
2354
2355     ff_mpeg_flush(avctx);
2356 }
2357
2358 static int mpeg_decode_end(AVCodecContext *avctx)
2359 {
2360     Mpeg1Context *s = avctx->priv_data;
2361
2362     if (s->mpeg_enc_ctx_allocated)
2363         ff_MPV_common_end(&s->mpeg_enc_ctx);
2364     return 0;
2365 }
2366
2367 static const AVProfile mpeg2_video_profiles[] = {
2368     { FF_PROFILE_MPEG2_422,          "4:2:2"              },
2369     { FF_PROFILE_MPEG2_HIGH,         "High"               },
2370     { FF_PROFILE_MPEG2_SS,           "Spatially Scalable" },
2371     { FF_PROFILE_MPEG2_SNR_SCALABLE, "SNR Scalable"       },
2372     { FF_PROFILE_MPEG2_MAIN,         "Main"               },
2373     { FF_PROFILE_MPEG2_SIMPLE,       "Simple"             },
2374     { FF_PROFILE_RESERVED,           "Reserved"           },
2375     { FF_PROFILE_RESERVED,           "Reserved"           },
2376     { FF_PROFILE_UNKNOWN },
2377 };
2378
2379
2380 AVCodec ff_mpeg1video_decoder = {
2381     .name                  = "mpeg1video",
2382     .type                  = AVMEDIA_TYPE_VIDEO,
2383     .id                    = AV_CODEC_ID_MPEG1VIDEO,
2384     .priv_data_size        = sizeof(Mpeg1Context),
2385     .init                  = mpeg_decode_init,
2386     .close                 = mpeg_decode_end,
2387     .decode                = mpeg_decode_frame,
2388     .capabilities          = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
2389                              CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2390                              CODEC_CAP_SLICE_THREADS,
2391     .flush                 = flush,
2392     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2393     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context)
2394 };
2395
2396 AVCodec ff_mpeg2video_decoder = {
2397     .name           = "mpeg2video",
2398     .type           = AVMEDIA_TYPE_VIDEO,
2399     .id             = AV_CODEC_ID_MPEG2VIDEO,
2400     .priv_data_size = sizeof(Mpeg1Context),
2401     .init           = mpeg_decode_init,
2402     .close          = mpeg_decode_end,
2403     .decode         = mpeg_decode_frame,
2404     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
2405                       CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2406                       CODEC_CAP_SLICE_THREADS,
2407     .flush          = flush,
2408     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2409     .profiles       = NULL_IF_CONFIG_SMALL(mpeg2_video_profiles),
2410 };
2411
2412 #if CONFIG_MPEG_XVMC_DECODER
2413 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx)
2414 {
2415     if (avctx->active_thread_type & FF_THREAD_SLICE)
2416         return -1;
2417     if (!(avctx->slice_flags & SLICE_FLAG_CODED_ORDER))
2418         return -1;
2419     if (!(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
2420         av_dlog(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2421     }
2422     mpeg_decode_init(avctx);
2423
2424     avctx->pix_fmt           = AV_PIX_FMT_XVMC_MPEG2_IDCT;
2425     avctx->xvmc_acceleration = 2; // 2 - the blocks are packed!
2426
2427     return 0;
2428 }
2429
2430 AVCodec ff_mpeg_xvmc_decoder = {
2431     .name           = "mpegvideo_xvmc",
2432     .type           = AVMEDIA_TYPE_VIDEO,
2433     .id             = AV_CODEC_ID_MPEG2VIDEO_XVMC,
2434     .priv_data_size = sizeof(Mpeg1Context),
2435     .init           = mpeg_mc_decode_init,
2436     .close          = mpeg_decode_end,
2437     .decode         = mpeg_decode_frame,
2438     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
2439                       CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2440     .flush          = flush,
2441     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2442 };
2443
2444 #endif
2445
2446 #if CONFIG_MPEG_VDPAU_DECODER
2447 AVCodec ff_mpeg_vdpau_decoder = {
2448     .name           = "mpegvideo_vdpau",
2449     .type           = AVMEDIA_TYPE_VIDEO,
2450     .id             = AV_CODEC_ID_MPEG2VIDEO,
2451     .priv_data_size = sizeof(Mpeg1Context),
2452     .init           = mpeg_decode_init,
2453     .close          = mpeg_decode_end,
2454     .decode         = mpeg_decode_frame,
2455     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED |
2456                       CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2457     .flush          = flush,
2458     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2459 };
2460 #endif
2461
2462 #if CONFIG_MPEG1_VDPAU_DECODER
2463 AVCodec ff_mpeg1_vdpau_decoder = {
2464     .name           = "mpeg1video_vdpau",
2465     .type           = AVMEDIA_TYPE_VIDEO,
2466     .id             = AV_CODEC_ID_MPEG1VIDEO,
2467     .priv_data_size = sizeof(Mpeg1Context),
2468     .init           = mpeg_decode_init,
2469     .close          = mpeg_decode_end,
2470     .decode         = mpeg_decode_frame,
2471     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED |
2472                       CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2473     .flush          = flush,
2474     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2475 };
2476 #endif