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1 /*
2  * MPEG-1/2 decoder
3  * Copyright (c) 2000, 2001 Fabrice Bellard
4  * Copyright (c) 2002-2013 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22
23 /**
24  * @file
25  * MPEG-1/2 decoder
26  */
27
28 #define UNCHECKED_BITSTREAM_READER 1
29 #include <inttypes.h>
30
31 #include "libavutil/attributes.h"
32 #include "libavutil/imgutils.h"
33 #include "libavutil/internal.h"
34 #include "libavutil/stereo3d.h"
35
36 #include "avcodec.h"
37 #include "bytestream.h"
38 #include "error_resilience.h"
39 #include "hwaccel.h"
40 #include "idctdsp.h"
41 #include "internal.h"
42 #include "mpeg_er.h"
43 #include "mpeg12.h"
44 #include "mpeg12data.h"
45 #include "mpegutils.h"
46 #include "mpegvideo.h"
47 #include "mpegvideodata.h"
48 #include "profiles.h"
49 #include "thread.h"
50 #include "version.h"
51 #include "xvmc_internal.h"
52
53 typedef struct Mpeg1Context {
54     MpegEncContext mpeg_enc_ctx;
55     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
56     int repeat_field;           /* true if we must repeat the field */
57     AVPanScan pan_scan;         /* some temporary storage for the panscan */
58     AVStereo3D stereo3d;
59     int has_stereo3d;
60     uint8_t *a53_caption;
61     int a53_caption_size;
62     uint8_t afd;
63     int has_afd;
64     int slice_count;
65     AVRational save_aspect;
66     int save_width, save_height, save_progressive_seq;
67     AVRational frame_rate_ext;  /* MPEG-2 specific framerate modificator */
68     int sync;                   /* Did we reach a sync point like a GOP/SEQ/KEYFrame? */
69     int tmpgexs;
70     int first_slice;
71     int extradata_decoded;
72 } Mpeg1Context;
73
74 #define MB_TYPE_ZERO_MV   0x20000000
75
76 static const uint32_t ptype2mb_type[7] = {
77                     MB_TYPE_INTRA,
78                     MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_ZERO_MV | MB_TYPE_16x16,
79                     MB_TYPE_L0,
80                     MB_TYPE_L0 | MB_TYPE_CBP,
81     MB_TYPE_QUANT | MB_TYPE_INTRA,
82     MB_TYPE_QUANT | MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_ZERO_MV | MB_TYPE_16x16,
83     MB_TYPE_QUANT | MB_TYPE_L0 | MB_TYPE_CBP,
84 };
85
86 static const uint32_t btype2mb_type[11] = {
87                     MB_TYPE_INTRA,
88                     MB_TYPE_L1,
89                     MB_TYPE_L1   | MB_TYPE_CBP,
90                     MB_TYPE_L0,
91                     MB_TYPE_L0   | MB_TYPE_CBP,
92                     MB_TYPE_L0L1,
93                     MB_TYPE_L0L1 | MB_TYPE_CBP,
94     MB_TYPE_QUANT | MB_TYPE_INTRA,
95     MB_TYPE_QUANT | MB_TYPE_L1   | MB_TYPE_CBP,
96     MB_TYPE_QUANT | MB_TYPE_L0   | MB_TYPE_CBP,
97     MB_TYPE_QUANT | MB_TYPE_L0L1 | MB_TYPE_CBP,
98 };
99
100 /* as H.263, but only 17 codes */
101 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
102 {
103     int code, sign, val, shift;
104
105     code = get_vlc2(&s->gb, ff_mv_vlc.table, MV_VLC_BITS, 2);
106     if (code == 0)
107         return pred;
108     if (code < 0)
109         return 0xffff;
110
111     sign  = get_bits1(&s->gb);
112     shift = fcode - 1;
113     val   = code;
114     if (shift) {
115         val  = (val - 1) << shift;
116         val |= get_bits(&s->gb, shift);
117         val++;
118     }
119     if (sign)
120         val = -val;
121     val += pred;
122
123     /* modulo decoding */
124     return sign_extend(val, 5 + shift);
125 }
126
127 #define MAX_INDEX (64 - 1)
128 #define check_scantable_index(ctx, x)                                         \
129     do {                                                                      \
130         if ((x) > MAX_INDEX) {                                                \
131             av_log(ctx->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n",     \
132                    ctx->mb_x, ctx->mb_y);                                     \
133             return AVERROR_INVALIDDATA;                                       \
134         }                                                                     \
135     } while (0)
136
137 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
138                                            int16_t *block, int n)
139 {
140     int level, i, j, run;
141     RLTable *rl                  = &ff_rl_mpeg1;
142     uint8_t *const scantable     = s->intra_scantable.permutated;
143     const uint16_t *quant_matrix = s->inter_matrix;
144     const int qscale             = s->qscale;
145
146     {
147         OPEN_READER(re, &s->gb);
148         i = -1;
149         // special case for first coefficient, no need to add second VLC table
150         UPDATE_CACHE(re, &s->gb);
151         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
152             level = (3 * qscale * quant_matrix[0]) >> 5;
153             level = (level - 1) | 1;
154             if (GET_CACHE(re, &s->gb) & 0x40000000)
155                 level = -level;
156             block[0] = level;
157             i++;
158             SKIP_BITS(re, &s->gb, 2);
159             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
160                 goto end;
161         }
162         /* now quantify & encode AC coefficients */
163         for (;;) {
164             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
165                        TEX_VLC_BITS, 2, 0);
166
167             if (level != 0) {
168                 i += run;
169                 if (i > MAX_INDEX)
170                     break;
171                 j = scantable[i];
172                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
173                 level = (level - 1) | 1;
174                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
175                         SHOW_SBITS(re, &s->gb, 1);
176                 SKIP_BITS(re, &s->gb, 1);
177             } else {
178                 /* escape */
179                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
180                 LAST_SKIP_BITS(re, &s->gb, 6);
181                 UPDATE_CACHE(re, &s->gb);
182                 level = SHOW_SBITS(re, &s->gb, 8);
183                 SKIP_BITS(re, &s->gb, 8);
184                 if (level == -128) {
185                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
186                     SKIP_BITS(re, &s->gb, 8);
187                 } else if (level == 0) {
188                     level = SHOW_UBITS(re, &s->gb, 8);
189                     SKIP_BITS(re, &s->gb, 8);
190                 }
191                 i += run;
192                 if (i > MAX_INDEX)
193                     break;
194                 j = scantable[i];
195                 if (level < 0) {
196                     level = -level;
197                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
198                     level = (level - 1) | 1;
199                     level = -level;
200                 } else {
201                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
202                     level = (level - 1) | 1;
203                 }
204             }
205
206             block[j] = level;
207             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
208                 break;
209             UPDATE_CACHE(re, &s->gb);
210         }
211 end:
212         LAST_SKIP_BITS(re, &s->gb, 2);
213         CLOSE_READER(re, &s->gb);
214     }
215
216     check_scantable_index(s, i);
217
218     s->block_last_index[n] = i;
219     return 0;
220 }
221
222 /**
223  * Note: this function can read out of range and crash for corrupt streams.
224  * Changing this would eat up any speed benefits it has.
225  * Do not use "fast" flag if you need the code to be robust.
226  */
227 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s,
228                                                 int16_t *block, int n)
229 {
230     int level, i, j, run;
231     RLTable *rl              = &ff_rl_mpeg1;
232     uint8_t *const scantable = s->intra_scantable.permutated;
233     const int qscale         = s->qscale;
234
235     {
236         OPEN_READER(re, &s->gb);
237         i = -1;
238         // Special case for first coefficient, no need to add second VLC table.
239         UPDATE_CACHE(re, &s->gb);
240         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
241             level = (3 * qscale) >> 1;
242             level = (level - 1) | 1;
243             if (GET_CACHE(re, &s->gb) & 0x40000000)
244                 level = -level;
245             block[0] = level;
246             i++;
247             SKIP_BITS(re, &s->gb, 2);
248             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
249                 goto end;
250         }
251
252         /* now quantify & encode AC coefficients */
253         for (;;) {
254             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
255                        TEX_VLC_BITS, 2, 0);
256
257             if (level != 0) {
258                 i += run;
259                 if (i > MAX_INDEX)
260                     break;
261                 j = scantable[i];
262                 level = ((level * 2 + 1) * qscale) >> 1;
263                 level = (level - 1) | 1;
264                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
265                         SHOW_SBITS(re, &s->gb, 1);
266                 SKIP_BITS(re, &s->gb, 1);
267             } else {
268                 /* escape */
269                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
270                 LAST_SKIP_BITS(re, &s->gb, 6);
271                 UPDATE_CACHE(re, &s->gb);
272                 level = SHOW_SBITS(re, &s->gb, 8);
273                 SKIP_BITS(re, &s->gb, 8);
274                 if (level == -128) {
275                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
276                     SKIP_BITS(re, &s->gb, 8);
277                 } else if (level == 0) {
278                     level = SHOW_UBITS(re, &s->gb, 8);
279                     SKIP_BITS(re, &s->gb, 8);
280                 }
281                 i += run;
282                 if (i > MAX_INDEX)
283                     break;
284                 j = scantable[i];
285                 if (level < 0) {
286                     level = -level;
287                     level = ((level * 2 + 1) * qscale) >> 1;
288                     level = (level - 1) | 1;
289                     level = -level;
290                 } else {
291                     level = ((level * 2 + 1) * qscale) >> 1;
292                     level = (level - 1) | 1;
293                 }
294             }
295
296             block[j] = level;
297             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
298                 break;
299             UPDATE_CACHE(re, &s->gb);
300         }
301 end:
302         LAST_SKIP_BITS(re, &s->gb, 2);
303         CLOSE_READER(re, &s->gb);
304     }
305
306     check_scantable_index(s, i);
307
308     s->block_last_index[n] = i;
309     return 0;
310 }
311
312 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
313                                                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],
349                        TEX_VLC_BITS, 2, 0);
350
351             if (level != 0) {
352                 i += run;
353                 if (i > MAX_INDEX)
354                     break;
355                 j = scantable[i];
356                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
357                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
358                         SHOW_SBITS(re, &s->gb, 1);
359                 SKIP_BITS(re, &s->gb, 1);
360             } else {
361                 /* escape */
362                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
363                 LAST_SKIP_BITS(re, &s->gb, 6);
364                 UPDATE_CACHE(re, &s->gb);
365                 level = SHOW_SBITS(re, &s->gb, 12);
366                 SKIP_BITS(re, &s->gb, 12);
367
368                 i += run;
369                 if (i > MAX_INDEX)
370                     break;
371                 j = scantable[i];
372                 if (level < 0) {
373                     level = ((-level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
374                     level = -level;
375                 } else {
376                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
377                 }
378             }
379
380             mismatch ^= level;
381             block[j]  = level;
382             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
383                 break;
384             UPDATE_CACHE(re, &s->gb);
385         }
386 end:
387         LAST_SKIP_BITS(re, &s->gb, 2);
388         CLOSE_READER(re, &s->gb);
389     }
390     block[63] ^= (mismatch & 1);
391
392     check_scantable_index(s, i);
393
394     s->block_last_index[n] = i;
395     return 0;
396 }
397
398 /**
399  * Note: this function can read out of range and crash for corrupt streams.
400  * Changing this would eat up any speed benefits it has.
401  * Do not use "fast" flag if you need the code to be robust.
402  */
403 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
404                                                     int16_t *block, int n)
405 {
406     int level, i, j, run;
407     RLTable *rl              = &ff_rl_mpeg1;
408     uint8_t *const scantable = s->intra_scantable.permutated;
409     const int qscale         = s->qscale;
410     OPEN_READER(re, &s->gb);
411     i = -1;
412
413     // special case for first coefficient, no need to add second VLC table
414     UPDATE_CACHE(re, &s->gb);
415     if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
416         level = (3 * qscale) >> 1;
417         if (GET_CACHE(re, &s->gb) & 0x40000000)
418             level = -level;
419         block[0] = level;
420         i++;
421         SKIP_BITS(re, &s->gb, 2);
422         if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
423             goto end;
424     }
425
426     /* now quantify & encode AC coefficients */
427     for (;;) {
428         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
429
430         if (level != 0) {
431             i += run;
432             if (i > MAX_INDEX)
433                 break;
434             j = scantable[i];
435             level = ((level * 2 + 1) * qscale) >> 1;
436             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
437                     SHOW_SBITS(re, &s->gb, 1);
438             SKIP_BITS(re, &s->gb, 1);
439         } else {
440             /* escape */
441             run = SHOW_UBITS(re, &s->gb, 6) + 1;
442             LAST_SKIP_BITS(re, &s->gb, 6);
443             UPDATE_CACHE(re, &s->gb);
444             level = SHOW_SBITS(re, &s->gb, 12);
445             SKIP_BITS(re, &s->gb, 12);
446
447             i += run;
448             if (i > MAX_INDEX)
449                 break;
450             j = scantable[i];
451             if (level < 0) {
452                 level = ((-level * 2 + 1) * qscale) >> 1;
453                 level = -level;
454             } else {
455                 level = ((level * 2 + 1) * qscale) >> 1;
456             }
457         }
458
459         block[j] = level;
460         if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF || i > 63)
461             break;
462
463         UPDATE_CACHE(re, &s->gb);
464     }
465 end:
466     LAST_SKIP_BITS(re, &s->gb, 2);
467     CLOSE_READER(re, &s->gb);
468
469     check_scantable_index(s, i);
470
471     s->block_last_index[n] = i;
472     return 0;
473 }
474
475 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
476                                            int16_t *block, int n)
477 {
478     int level, dc, diff, i, j, run;
479     int component;
480     RLTable *rl;
481     uint8_t *const scantable = s->intra_scantable.permutated;
482     const uint16_t *quant_matrix;
483     const int qscale = s->qscale;
484     int mismatch;
485
486     /* DC coefficient */
487     if (n < 4) {
488         quant_matrix = s->intra_matrix;
489         component    = 0;
490     } else {
491         quant_matrix = s->chroma_intra_matrix;
492         component    = (n & 1) + 1;
493     }
494     diff = decode_dc(&s->gb, component);
495     if (diff >= 0xffff)
496         return AVERROR_INVALIDDATA;
497     dc  = s->last_dc[component];
498     dc += diff;
499     s->last_dc[component] = dc;
500     block[0] = dc * (1 << (3 - s->intra_dc_precision));
501     ff_tlog(s->avctx, "dc=%d\n", block[0]);
502     mismatch = block[0] ^ 1;
503     i = 0;
504     if (s->intra_vlc_format)
505         rl = &ff_rl_mpeg2;
506     else
507         rl = &ff_rl_mpeg1;
508
509     {
510         OPEN_READER(re, &s->gb);
511         /* now quantify & encode AC coefficients */
512         for (;;) {
513             UPDATE_CACHE(re, &s->gb);
514             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
515                        TEX_VLC_BITS, 2, 0);
516
517             if (level == 127) {
518                 break;
519             } else if (level != 0) {
520                 i += run;
521                 if (i > MAX_INDEX)
522                     break;
523                 j = scantable[i];
524                 level = (level * qscale * quant_matrix[j]) >> 4;
525                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
526                         SHOW_SBITS(re, &s->gb, 1);
527                 LAST_SKIP_BITS(re, &s->gb, 1);
528             } else {
529                 /* escape */
530                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
531                 LAST_SKIP_BITS(re, &s->gb, 6);
532                 UPDATE_CACHE(re, &s->gb);
533                 level = SHOW_SBITS(re, &s->gb, 12);
534                 SKIP_BITS(re, &s->gb, 12);
535                 i += run;
536                 if (i > MAX_INDEX)
537                     break;
538                 j = scantable[i];
539                 if (level < 0) {
540                     level = (-level * qscale * quant_matrix[j]) >> 4;
541                     level = -level;
542                 } else {
543                     level = (level * qscale * quant_matrix[j]) >> 4;
544                 }
545             }
546
547             mismatch ^= level;
548             block[j]  = level;
549         }
550         CLOSE_READER(re, &s->gb);
551     }
552     block[63] ^= mismatch & 1;
553
554     check_scantable_index(s, i);
555
556     s->block_last_index[n] = i;
557     return 0;
558 }
559
560 /**
561  * Note: this function can read out of range and crash for corrupt streams.
562  * Changing this would eat up any speed benefits it has.
563  * Do not use "fast" flag if you need the code to be robust.
564  */
565 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
566                                                 int16_t *block, int n)
567 {
568     int level, dc, diff, i, j, run;
569     int component;
570     RLTable *rl;
571     uint8_t *const scantable = s->intra_scantable.permutated;
572     const uint16_t *quant_matrix;
573     const int qscale = s->qscale;
574
575     /* DC coefficient */
576     if (n < 4) {
577         quant_matrix = s->intra_matrix;
578         component    = 0;
579     } else {
580         quant_matrix = s->chroma_intra_matrix;
581         component    = (n & 1) + 1;
582     }
583     diff = decode_dc(&s->gb, component);
584     if (diff >= 0xffff)
585         return AVERROR_INVALIDDATA;
586     dc = s->last_dc[component];
587     dc += diff;
588     s->last_dc[component] = dc;
589     block[0] = dc << (3 - s->intra_dc_precision);
590     i = 0;
591     if (s->intra_vlc_format)
592         rl = &ff_rl_mpeg2;
593     else
594         rl = &ff_rl_mpeg1;
595
596     {
597         OPEN_READER(re, &s->gb);
598         /* now quantify & encode AC coefficients */
599         for (;;) {
600             UPDATE_CACHE(re, &s->gb);
601             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
602                        TEX_VLC_BITS, 2, 0);
603
604             if (level >= 64 || i > 63) {
605                 break;
606             } else if (level != 0) {
607                 i += run;
608                 j = scantable[i];
609                 level = (level * qscale * quant_matrix[j]) >> 4;
610                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
611                         SHOW_SBITS(re, &s->gb, 1);
612                 LAST_SKIP_BITS(re, &s->gb, 1);
613             } else {
614                 /* escape */
615                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
616                 LAST_SKIP_BITS(re, &s->gb, 6);
617                 UPDATE_CACHE(re, &s->gb);
618                 level = SHOW_SBITS(re, &s->gb, 12);
619                 SKIP_BITS(re, &s->gb, 12);
620                 i += run;
621                 j = scantable[i];
622                 if (level < 0) {
623                     level = (-level * qscale * quant_matrix[j]) >> 4;
624                     level = -level;
625                 } else {
626                     level = (level * qscale * quant_matrix[j]) >> 4;
627                 }
628             }
629
630             block[j] = level;
631         }
632         CLOSE_READER(re, &s->gb);
633     }
634
635     check_scantable_index(s, i);
636
637     s->block_last_index[n] = i;
638     return 0;
639 }
640
641 /******************************************/
642 /* decoding */
643
644 static inline int get_dmv(MpegEncContext *s)
645 {
646     if (get_bits1(&s->gb))
647         return 1 - (get_bits1(&s->gb) << 1);
648     else
649         return 0;
650 }
651
652 /* motion type (for MPEG-2) */
653 #define MT_FIELD 1
654 #define MT_FRAME 2
655 #define MT_16X8  2
656 #define MT_DMV   3
657
658 static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
659 {
660     int i, j, k, cbp, val, mb_type, motion_type;
661     const int mb_block_count = 4 + (1 << s->chroma_format);
662     int ret;
663
664     ff_tlog(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
665
666     av_assert2(s->mb_skipped == 0);
667
668     if (s->mb_skip_run-- != 0) {
669         if (s->pict_type == AV_PICTURE_TYPE_P) {
670             s->mb_skipped = 1;
671             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
672                 MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
673         } else {
674             int mb_type;
675
676             if (s->mb_x)
677                 mb_type = s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride - 1];
678             else
679                 // FIXME not sure if this is allowed in MPEG at all
680                 mb_type = s->current_picture.mb_type[s->mb_width + (s->mb_y - 1) * s->mb_stride - 1];
681             if (IS_INTRA(mb_type)) {
682                 av_log(s->avctx, AV_LOG_ERROR, "skip with previntra\n");
683                 return AVERROR_INVALIDDATA;
684             }
685             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
686                 mb_type | MB_TYPE_SKIP;
687
688             if ((s->mv[0][0][0] | s->mv[0][0][1] | s->mv[1][0][0] | s->mv[1][0][1]) == 0)
689                 s->mb_skipped = 1;
690         }
691
692         return 0;
693     }
694
695     switch (s->pict_type) {
696     default:
697     case AV_PICTURE_TYPE_I:
698         if (get_bits1(&s->gb) == 0) {
699             if (get_bits1(&s->gb) == 0) {
700                 av_log(s->avctx, AV_LOG_ERROR,
701                        "Invalid mb type in I-frame at %d %d\n",
702                        s->mb_x, s->mb_y);
703                 return AVERROR_INVALIDDATA;
704             }
705             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
706         } else {
707             mb_type = MB_TYPE_INTRA;
708         }
709         break;
710     case AV_PICTURE_TYPE_P:
711         mb_type = get_vlc2(&s->gb, ff_mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
712         if (mb_type < 0) {
713             av_log(s->avctx, AV_LOG_ERROR,
714                    "Invalid mb type in P-frame at %d %d\n", s->mb_x, s->mb_y);
715             return AVERROR_INVALIDDATA;
716         }
717         mb_type = ptype2mb_type[mb_type];
718         break;
719     case AV_PICTURE_TYPE_B:
720         mb_type = get_vlc2(&s->gb, ff_mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
721         if (mb_type < 0) {
722             av_log(s->avctx, AV_LOG_ERROR,
723                    "Invalid mb type in B-frame at %d %d\n", s->mb_x, s->mb_y);
724             return AVERROR_INVALIDDATA;
725         }
726         mb_type = btype2mb_type[mb_type];
727         break;
728     }
729     ff_tlog(s->avctx, "mb_type=%x\n", mb_type);
730 //    motion_type = 0; /* avoid warning */
731     if (IS_INTRA(mb_type)) {
732         s->bdsp.clear_blocks(s->block[0]);
733
734         if (!s->chroma_y_shift)
735             s->bdsp.clear_blocks(s->block[6]);
736
737         /* compute DCT type */
738         // FIXME: add an interlaced_dct coded var?
739         if (s->picture_structure == PICT_FRAME &&
740             !s->frame_pred_frame_dct)
741             s->interlaced_dct = get_bits1(&s->gb);
742
743         if (IS_QUANT(mb_type))
744             s->qscale = mpeg_get_qscale(s);
745
746         if (s->concealment_motion_vectors) {
747             /* just parse them */
748             if (s->picture_structure != PICT_FRAME)
749                 skip_bits1(&s->gb);  /* field select */
750
751             s->mv[0][0][0]      =
752             s->last_mv[0][0][0] =
753             s->last_mv[0][1][0] = mpeg_decode_motion(s, s->mpeg_f_code[0][0],
754                                                      s->last_mv[0][0][0]);
755             s->mv[0][0][1]      =
756             s->last_mv[0][0][1] =
757             s->last_mv[0][1][1] = mpeg_decode_motion(s, s->mpeg_f_code[0][1],
758                                                      s->last_mv[0][0][1]);
759
760             check_marker(s->avctx, &s->gb, "after concealment_motion_vectors");
761         } else {
762             /* reset mv prediction */
763             memset(s->last_mv, 0, sizeof(s->last_mv));
764         }
765         s->mb_intra = 1;
766         // if 1, we memcpy blocks in xvmcvideo
767         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
768             ff_xvmc_pack_pblocks(s, -1); // inter are always full blocks
769
770         if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
771             if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
772                 for (i = 0; i < 6; i++)
773                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
774             } else {
775                 for (i = 0; i < mb_block_count; i++)
776                     if ((ret = mpeg2_decode_block_intra(s, *s->pblocks[i], i)) < 0)
777                         return ret;
778             }
779         } else {
780             for (i = 0; i < 6; i++) {
781                 ret = ff_mpeg1_decode_block_intra(&s->gb,
782                                                   s->intra_matrix,
783                                                   s->intra_scantable.permutated,
784                                                   s->last_dc, *s->pblocks[i],
785                                                   i, s->qscale);
786                 if (ret < 0) {
787                     av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n",
788                            s->mb_x, s->mb_y);
789                     return ret;
790                 }
791
792                 s->block_last_index[i] = ret;
793             }
794         }
795     } else {
796         if (mb_type & MB_TYPE_ZERO_MV) {
797             av_assert2(mb_type & MB_TYPE_CBP);
798
799             s->mv_dir = MV_DIR_FORWARD;
800             if (s->picture_structure == PICT_FRAME) {
801                 if (s->picture_structure == PICT_FRAME
802                     && !s->frame_pred_frame_dct)
803                     s->interlaced_dct = get_bits1(&s->gb);
804                 s->mv_type = MV_TYPE_16X16;
805             } else {
806                 s->mv_type            = MV_TYPE_FIELD;
807                 mb_type              |= MB_TYPE_INTERLACED;
808                 s->field_select[0][0] = s->picture_structure - 1;
809             }
810
811             if (IS_QUANT(mb_type))
812                 s->qscale = mpeg_get_qscale(s);
813
814             s->last_mv[0][0][0] = 0;
815             s->last_mv[0][0][1] = 0;
816             s->last_mv[0][1][0] = 0;
817             s->last_mv[0][1][1] = 0;
818             s->mv[0][0][0]      = 0;
819             s->mv[0][0][1]      = 0;
820         } else {
821             av_assert2(mb_type & MB_TYPE_L0L1);
822             // FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
823             /* get additional motion vector type */
824             if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) {
825                 motion_type = MT_FRAME;
826             } else {
827                 motion_type = get_bits(&s->gb, 2);
828                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
829                     s->interlaced_dct = get_bits1(&s->gb);
830             }
831
832             if (IS_QUANT(mb_type))
833                 s->qscale = mpeg_get_qscale(s);
834
835             /* motion vectors */
836             s->mv_dir = (mb_type >> 13) & 3;
837             ff_tlog(s->avctx, "motion_type=%d\n", motion_type);
838             switch (motion_type) {
839             case MT_FRAME: /* or MT_16X8 */
840                 if (s->picture_structure == PICT_FRAME) {
841                     mb_type   |= MB_TYPE_16x16;
842                     s->mv_type = MV_TYPE_16X16;
843                     for (i = 0; i < 2; i++) {
844                         if (USES_LIST(mb_type, i)) {
845                             /* MT_FRAME */
846                             s->mv[i][0][0]      =
847                             s->last_mv[i][0][0] =
848                             s->last_mv[i][1][0] =
849                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0],
850                                                    s->last_mv[i][0][0]);
851                             s->mv[i][0][1]      =
852                             s->last_mv[i][0][1] =
853                             s->last_mv[i][1][1] =
854                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1],
855                                                    s->last_mv[i][0][1]);
856                             /* full_pel: only for MPEG-1 */
857                             if (s->full_pel[i]) {
858                                 s->mv[i][0][0] *= 2;
859                                 s->mv[i][0][1] *= 2;
860                             }
861                         }
862                     }
863                 } else {
864                     mb_type   |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
865                     s->mv_type = MV_TYPE_16X8;
866                     for (i = 0; i < 2; i++) {
867                         if (USES_LIST(mb_type, i)) {
868                             /* MT_16X8 */
869                             for (j = 0; j < 2; j++) {
870                                 s->field_select[i][j] = get_bits1(&s->gb);
871                                 for (k = 0; k < 2; k++) {
872                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
873                                                              s->last_mv[i][j][k]);
874                                     s->last_mv[i][j][k] = val;
875                                     s->mv[i][j][k]      = val;
876                                 }
877                             }
878                         }
879                     }
880                 }
881                 break;
882             case MT_FIELD:
883                 s->mv_type = MV_TYPE_FIELD;
884                 if (s->picture_structure == PICT_FRAME) {
885                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
886                     for (i = 0; i < 2; i++) {
887                         if (USES_LIST(mb_type, i)) {
888                             for (j = 0; j < 2; j++) {
889                                 s->field_select[i][j] = get_bits1(&s->gb);
890                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
891                                                          s->last_mv[i][j][0]);
892                                 s->last_mv[i][j][0] = val;
893                                 s->mv[i][j][0]      = val;
894                                 ff_tlog(s->avctx, "fmx=%d\n", val);
895                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
896                                                          s->last_mv[i][j][1] >> 1);
897                                 s->last_mv[i][j][1] = 2 * val;
898                                 s->mv[i][j][1]      = val;
899                                 ff_tlog(s->avctx, "fmy=%d\n", val);
900                             }
901                         }
902                     }
903                 } else {
904                     av_assert0(!s->progressive_sequence);
905                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
906                     for (i = 0; i < 2; i++) {
907                         if (USES_LIST(mb_type, i)) {
908                             s->field_select[i][0] = get_bits1(&s->gb);
909                             for (k = 0; k < 2; k++) {
910                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
911                                                          s->last_mv[i][0][k]);
912                                 s->last_mv[i][0][k] = val;
913                                 s->last_mv[i][1][k] = val;
914                                 s->mv[i][0][k]      = val;
915                             }
916                         }
917                     }
918                 }
919                 break;
920             case MT_DMV:
921                 if (s->progressive_sequence){
922                     av_log(s->avctx, AV_LOG_ERROR, "MT_DMV in progressive_sequence\n");
923                     return AVERROR_INVALIDDATA;
924                 }
925                 s->mv_type = MV_TYPE_DMV;
926                 for (i = 0; i < 2; i++) {
927                     if (USES_LIST(mb_type, i)) {
928                         int dmx, dmy, mx, my, m;
929                         const int my_shift = s->picture_structure == PICT_FRAME;
930
931                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
932                                                 s->last_mv[i][0][0]);
933                         s->last_mv[i][0][0] = mx;
934                         s->last_mv[i][1][0] = mx;
935                         dmx = get_dmv(s);
936                         my  = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
937                                                  s->last_mv[i][0][1] >> my_shift);
938                         dmy = get_dmv(s);
939
940
941                         s->last_mv[i][0][1] = my * (1 << my_shift);
942                         s->last_mv[i][1][1] = my * (1 << my_shift);
943
944                         s->mv[i][0][0] = mx;
945                         s->mv[i][0][1] = my;
946                         s->mv[i][1][0] = mx; // not used
947                         s->mv[i][1][1] = my; // not used
948
949                         if (s->picture_structure == PICT_FRAME) {
950                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
951
952                             // m = 1 + 2 * s->top_field_first;
953                             m = s->top_field_first ? 1 : 3;
954
955                             /* top -> top pred */
956                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
957                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
958                             m = 4 - m;
959                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
960                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
961                         } else {
962                             mb_type |= MB_TYPE_16x16;
963
964                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
965                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
966                             if (s->picture_structure == PICT_TOP_FIELD)
967                                 s->mv[i][2][1]--;
968                             else
969                                 s->mv[i][2][1]++;
970                         }
971                     }
972                 }
973                 break;
974             default:
975                 av_log(s->avctx, AV_LOG_ERROR,
976                        "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
977                 return AVERROR_INVALIDDATA;
978             }
979         }
980
981         s->mb_intra = 0;
982         if (HAS_CBP(mb_type)) {
983             s->bdsp.clear_blocks(s->block[0]);
984
985             cbp = get_vlc2(&s->gb, ff_mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
986             if (mb_block_count > 6) {
987                 cbp *= 1 << mb_block_count - 6;
988                 cbp  |= get_bits(&s->gb, mb_block_count - 6);
989                 s->bdsp.clear_blocks(s->block[6]);
990             }
991             if (cbp <= 0) {
992                 av_log(s->avctx, AV_LOG_ERROR,
993                        "invalid cbp %d at %d %d\n", cbp, s->mb_x, s->mb_y);
994                 return AVERROR_INVALIDDATA;
995             }
996
997             // if 1, we memcpy blocks in xvmcvideo
998             if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
999                 ff_xvmc_pack_pblocks(s, cbp);
1000
1001             if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
1002                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1003                     for (i = 0; i < 6; i++) {
1004                         if (cbp & 32)
1005                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
1006                         else
1007                             s->block_last_index[i] = -1;
1008                         cbp += cbp;
1009                     }
1010                 } else {
1011                     cbp <<= 12 - mb_block_count;
1012
1013                     for (i = 0; i < mb_block_count; i++) {
1014                         if (cbp & (1 << 11)) {
1015                             if ((ret = mpeg2_decode_block_non_intra(s, *s->pblocks[i], i)) < 0)
1016                                 return ret;
1017                         } else {
1018                             s->block_last_index[i] = -1;
1019                         }
1020                         cbp += cbp;
1021                     }
1022                 }
1023             } else {
1024                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1025                     for (i = 0; i < 6; i++) {
1026                         if (cbp & 32)
1027                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
1028                         else
1029                             s->block_last_index[i] = -1;
1030                         cbp += cbp;
1031                     }
1032                 } else {
1033                     for (i = 0; i < 6; i++) {
1034                         if (cbp & 32) {
1035                             if ((ret = mpeg1_decode_block_inter(s, *s->pblocks[i], i)) < 0)
1036                                 return ret;
1037                         } else {
1038                             s->block_last_index[i] = -1;
1039                         }
1040                         cbp += cbp;
1041                     }
1042                 }
1043             }
1044         } else {
1045             for (i = 0; i < 12; i++)
1046                 s->block_last_index[i] = -1;
1047         }
1048     }
1049
1050     s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] = mb_type;
1051
1052     return 0;
1053 }
1054
1055 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1056 {
1057     Mpeg1Context *s    = avctx->priv_data;
1058     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1059
1060     ff_mpv_decode_defaults(s2);
1061
1062     if (   avctx->codec_tag != AV_RL32("VCR2")
1063         && avctx->codec_tag != AV_RL32("BW10"))
1064         avctx->coded_width = avctx->coded_height = 0; // do not trust dimensions from input
1065     ff_mpv_decode_init(s2, avctx);
1066
1067     s->mpeg_enc_ctx.avctx  = avctx;
1068
1069     /* we need some permutation to store matrices,
1070      * until the decoder sets the real permutation. */
1071     ff_mpv_idct_init(s2);
1072     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1073     ff_mpeg12_init_vlcs();
1074
1075     s2->chroma_format              = 1;
1076     s->mpeg_enc_ctx_allocated      = 0;
1077     s->mpeg_enc_ctx.picture_number = 0;
1078     s->repeat_field                = 0;
1079     s->mpeg_enc_ctx.codec_id       = avctx->codec->id;
1080     avctx->color_range             = AVCOL_RANGE_MPEG;
1081     return 0;
1082 }
1083
1084 #if HAVE_THREADS
1085 static int mpeg_decode_update_thread_context(AVCodecContext *avctx,
1086                                              const AVCodecContext *avctx_from)
1087 {
1088     Mpeg1Context *ctx = avctx->priv_data, *ctx_from = avctx_from->priv_data;
1089     MpegEncContext *s = &ctx->mpeg_enc_ctx, *s1 = &ctx_from->mpeg_enc_ctx;
1090     int err;
1091
1092     if (avctx == avctx_from               ||
1093         !ctx_from->mpeg_enc_ctx_allocated ||
1094         !s1->context_initialized)
1095         return 0;
1096
1097     err = ff_mpeg_update_thread_context(avctx, avctx_from);
1098     if (err)
1099         return err;
1100
1101     if (!ctx->mpeg_enc_ctx_allocated)
1102         memcpy(s + 1, s1 + 1, sizeof(Mpeg1Context) - sizeof(MpegEncContext));
1103
1104     if (!(s->pict_type == AV_PICTURE_TYPE_B || s->low_delay))
1105         s->picture_number++;
1106
1107     return 0;
1108 }
1109 #endif
1110
1111 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1112                                  const uint8_t *new_perm)
1113 {
1114     uint16_t temp_matrix[64];
1115     int i;
1116
1117     memcpy(temp_matrix, matrix, 64 * sizeof(uint16_t));
1118
1119     for (i = 0; i < 64; i++)
1120         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1121 }
1122
1123 static const enum AVPixelFormat mpeg1_hwaccel_pixfmt_list_420[] = {
1124 #if CONFIG_MPEG1_NVDEC_HWACCEL
1125     AV_PIX_FMT_CUDA,
1126 #endif
1127 #if CONFIG_MPEG1_XVMC_HWACCEL
1128     AV_PIX_FMT_XVMC,
1129 #endif
1130 #if CONFIG_MPEG1_VDPAU_HWACCEL
1131     AV_PIX_FMT_VDPAU,
1132 #endif
1133     AV_PIX_FMT_YUV420P,
1134     AV_PIX_FMT_NONE
1135 };
1136
1137 static const enum AVPixelFormat mpeg2_hwaccel_pixfmt_list_420[] = {
1138 #if CONFIG_MPEG2_NVDEC_HWACCEL
1139     AV_PIX_FMT_CUDA,
1140 #endif
1141 #if CONFIG_MPEG2_XVMC_HWACCEL
1142     AV_PIX_FMT_XVMC,
1143 #endif
1144 #if CONFIG_MPEG2_VDPAU_HWACCEL
1145     AV_PIX_FMT_VDPAU,
1146 #endif
1147 #if CONFIG_MPEG2_DXVA2_HWACCEL
1148     AV_PIX_FMT_DXVA2_VLD,
1149 #endif
1150 #if CONFIG_MPEG2_D3D11VA_HWACCEL
1151     AV_PIX_FMT_D3D11VA_VLD,
1152     AV_PIX_FMT_D3D11,
1153 #endif
1154 #if CONFIG_MPEG2_VAAPI_HWACCEL
1155     AV_PIX_FMT_VAAPI,
1156 #endif
1157 #if CONFIG_MPEG2_VIDEOTOOLBOX_HWACCEL
1158     AV_PIX_FMT_VIDEOTOOLBOX,
1159 #endif
1160     AV_PIX_FMT_YUV420P,
1161     AV_PIX_FMT_NONE
1162 };
1163
1164 static const enum AVPixelFormat mpeg12_pixfmt_list_422[] = {
1165     AV_PIX_FMT_YUV422P,
1166     AV_PIX_FMT_NONE
1167 };
1168
1169 static const enum AVPixelFormat mpeg12_pixfmt_list_444[] = {
1170     AV_PIX_FMT_YUV444P,
1171     AV_PIX_FMT_NONE
1172 };
1173
1174 static enum AVPixelFormat mpeg_get_pixelformat(AVCodecContext *avctx)
1175 {
1176     Mpeg1Context *s1  = avctx->priv_data;
1177     MpegEncContext *s = &s1->mpeg_enc_ctx;
1178     const enum AVPixelFormat *pix_fmts;
1179
1180     if (CONFIG_GRAY && (avctx->flags & AV_CODEC_FLAG_GRAY))
1181         return AV_PIX_FMT_GRAY8;
1182
1183     if (s->chroma_format < 2)
1184         pix_fmts = avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO ?
1185                                 mpeg1_hwaccel_pixfmt_list_420 :
1186                                 mpeg2_hwaccel_pixfmt_list_420;
1187     else if (s->chroma_format == 2)
1188         pix_fmts = mpeg12_pixfmt_list_422;
1189     else
1190         pix_fmts = mpeg12_pixfmt_list_444;
1191
1192     return ff_thread_get_format(avctx, pix_fmts);
1193 }
1194
1195 static void setup_hwaccel_for_pixfmt(AVCodecContext *avctx)
1196 {
1197     // until then pix_fmt may be changed right after codec init
1198     if (avctx->hwaccel)
1199         if (avctx->idct_algo == FF_IDCT_AUTO)
1200             avctx->idct_algo = FF_IDCT_NONE;
1201
1202     if (avctx->hwaccel && avctx->pix_fmt == AV_PIX_FMT_XVMC) {
1203         Mpeg1Context *s1 = avctx->priv_data;
1204         MpegEncContext *s = &s1->mpeg_enc_ctx;
1205
1206         s->pack_pblocks = 1;
1207     }
1208 }
1209
1210 /* Call this function when we know all parameters.
1211  * It may be called in different places for MPEG-1 and MPEG-2. */
1212 static int mpeg_decode_postinit(AVCodecContext *avctx)
1213 {
1214     Mpeg1Context *s1  = avctx->priv_data;
1215     MpegEncContext *s = &s1->mpeg_enc_ctx;
1216     uint8_t old_permutation[64];
1217     int ret;
1218
1219     if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1220         // MPEG-1 aspect
1221         AVRational aspect_inv = av_d2q(ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1222         avctx->sample_aspect_ratio = (AVRational) { aspect_inv.den, aspect_inv.num };
1223     } else { // MPEG-2
1224         // MPEG-2 aspect
1225         if (s->aspect_ratio_info > 1) {
1226             AVRational dar =
1227                 av_mul_q(av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1228                                   (AVRational) { s1->pan_scan.width,
1229                                                  s1->pan_scan.height }),
1230                          (AVRational) { s->width, s->height });
1231
1232             /* We ignore the spec here and guess a bit as reality does not
1233              * match the spec, see for example res_change_ffmpeg_aspect.ts
1234              * and sequence-display-aspect.mpg.
1235              * issue1613, 621, 562 */
1236             if ((s1->pan_scan.width == 0) || (s1->pan_scan.height == 0) ||
1237                 (av_cmp_q(dar, (AVRational) { 4, 3 }) &&
1238                  av_cmp_q(dar, (AVRational) { 16, 9 }))) {
1239                 s->avctx->sample_aspect_ratio =
1240                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1241                              (AVRational) { s->width, s->height });
1242             } else {
1243                 s->avctx->sample_aspect_ratio =
1244                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1245                              (AVRational) { s1->pan_scan.width, s1->pan_scan.height });
1246 // issue1613 4/3 16/9 -> 16/9
1247 // res_change_ffmpeg_aspect.ts 4/3 225/44 ->4/3
1248 // widescreen-issue562.mpg 4/3 16/9 -> 16/9
1249 //                s->avctx->sample_aspect_ratio = av_mul_q(s->avctx->sample_aspect_ratio, (AVRational) {s->width, s->height});
1250                 ff_dlog(avctx, "aspect A %d/%d\n",
1251                         ff_mpeg2_aspect[s->aspect_ratio_info].num,
1252                         ff_mpeg2_aspect[s->aspect_ratio_info].den);
1253                 ff_dlog(avctx, "aspect B %d/%d\n", s->avctx->sample_aspect_ratio.num,
1254                         s->avctx->sample_aspect_ratio.den);
1255             }
1256         } else {
1257             s->avctx->sample_aspect_ratio =
1258                 ff_mpeg2_aspect[s->aspect_ratio_info];
1259         }
1260     } // MPEG-2
1261
1262     if (av_image_check_sar(s->width, s->height,
1263                            avctx->sample_aspect_ratio) < 0) {
1264         av_log(avctx, AV_LOG_WARNING, "ignoring invalid SAR: %u/%u\n",
1265                 avctx->sample_aspect_ratio.num,
1266                 avctx->sample_aspect_ratio.den);
1267         avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
1268     }
1269
1270     if ((s1->mpeg_enc_ctx_allocated == 0)                   ||
1271         avctx->coded_width       != s->width                ||
1272         avctx->coded_height      != s->height               ||
1273         s1->save_width           != s->width                ||
1274         s1->save_height          != s->height               ||
1275         av_cmp_q(s1->save_aspect, s->avctx->sample_aspect_ratio) ||
1276         (s1->save_progressive_seq != s->progressive_sequence && FFALIGN(s->height, 16) != FFALIGN(s->height, 32)) ||
1277         0) {
1278         if (s1->mpeg_enc_ctx_allocated) {
1279             ParseContext pc = s->parse_context;
1280             s->parse_context.buffer = 0;
1281             ff_mpv_common_end(s);
1282             s->parse_context = pc;
1283             s1->mpeg_enc_ctx_allocated = 0;
1284         }
1285
1286         ret = ff_set_dimensions(avctx, s->width, s->height);
1287         if (ret < 0)
1288             return ret;
1289
1290         if (avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO && s->bit_rate) {
1291             avctx->rc_max_rate = s->bit_rate;
1292         } else if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO && s->bit_rate &&
1293                    (s->bit_rate != 0x3FFFF*400 || s->vbv_delay != 0xFFFF)) {
1294             avctx->bit_rate = s->bit_rate;
1295         }
1296         s1->save_aspect          = s->avctx->sample_aspect_ratio;
1297         s1->save_width           = s->width;
1298         s1->save_height          = s->height;
1299         s1->save_progressive_seq = s->progressive_sequence;
1300
1301         /* low_delay may be forced, in this case we will have B-frames
1302          * that behave like P-frames. */
1303         avctx->has_b_frames = !s->low_delay;
1304
1305         if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1306             // MPEG-1 fps
1307             avctx->framerate = ff_mpeg12_frame_rate_tab[s->frame_rate_index];
1308             avctx->ticks_per_frame     = 1;
1309
1310             avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1311         } else { // MPEG-2
1312             // MPEG-2 fps
1313             av_reduce(&s->avctx->framerate.num,
1314                       &s->avctx->framerate.den,
1315                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1316                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1317                       1 << 30);
1318             avctx->ticks_per_frame = 2;
1319
1320             switch (s->chroma_format) {
1321             case 1: avctx->chroma_sample_location = AVCHROMA_LOC_LEFT; break;
1322             case 2:
1323             case 3: avctx->chroma_sample_location = AVCHROMA_LOC_TOPLEFT; break;
1324             default: av_assert0(0);
1325             }
1326         } // MPEG-2
1327
1328         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1329         setup_hwaccel_for_pixfmt(avctx);
1330
1331         /* Quantization matrices may need reordering
1332          * if DCT permutation is changed. */
1333         memcpy(old_permutation, s->idsp.idct_permutation, 64 * sizeof(uint8_t));
1334
1335         ff_mpv_idct_init(s);
1336         if ((ret = ff_mpv_common_init(s)) < 0)
1337             return ret;
1338
1339         quant_matrix_rebuild(s->intra_matrix,        old_permutation, s->idsp.idct_permutation);
1340         quant_matrix_rebuild(s->inter_matrix,        old_permutation, s->idsp.idct_permutation);
1341         quant_matrix_rebuild(s->chroma_intra_matrix, old_permutation, s->idsp.idct_permutation);
1342         quant_matrix_rebuild(s->chroma_inter_matrix, old_permutation, s->idsp.idct_permutation);
1343
1344         s1->mpeg_enc_ctx_allocated = 1;
1345     }
1346     return 0;
1347 }
1348
1349 static int mpeg1_decode_picture(AVCodecContext *avctx, const uint8_t *buf,
1350                                 int buf_size)
1351 {
1352     Mpeg1Context *s1  = avctx->priv_data;
1353     MpegEncContext *s = &s1->mpeg_enc_ctx;
1354     int ref, f_code, vbv_delay;
1355
1356     init_get_bits(&s->gb, buf, buf_size * 8);
1357
1358     ref = get_bits(&s->gb, 10); /* temporal ref */
1359     s->pict_type = get_bits(&s->gb, 3);
1360     if (s->pict_type == 0 || s->pict_type > 3)
1361         return AVERROR_INVALIDDATA;
1362
1363     vbv_delay = get_bits(&s->gb, 16);
1364     s->vbv_delay = vbv_delay;
1365     if (s->pict_type == AV_PICTURE_TYPE_P ||
1366         s->pict_type == AV_PICTURE_TYPE_B) {
1367         s->full_pel[0] = get_bits1(&s->gb);
1368         f_code = get_bits(&s->gb, 3);
1369         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1370             return AVERROR_INVALIDDATA;
1371         f_code += !f_code;
1372         s->mpeg_f_code[0][0] = f_code;
1373         s->mpeg_f_code[0][1] = f_code;
1374     }
1375     if (s->pict_type == AV_PICTURE_TYPE_B) {
1376         s->full_pel[1] = get_bits1(&s->gb);
1377         f_code = get_bits(&s->gb, 3);
1378         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1379             return AVERROR_INVALIDDATA;
1380         f_code += !f_code;
1381         s->mpeg_f_code[1][0] = f_code;
1382         s->mpeg_f_code[1][1] = f_code;
1383     }
1384     s->current_picture.f->pict_type = s->pict_type;
1385     s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1386
1387     if (avctx->debug & FF_DEBUG_PICT_INFO)
1388         av_log(avctx, AV_LOG_DEBUG,
1389                "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1390
1391     s->y_dc_scale = 8;
1392     s->c_dc_scale = 8;
1393     return 0;
1394 }
1395
1396 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1397 {
1398     MpegEncContext *s = &s1->mpeg_enc_ctx;
1399     int horiz_size_ext, vert_size_ext;
1400     int bit_rate_ext;
1401
1402     skip_bits(&s->gb, 1); /* profile and level esc*/
1403     s->avctx->profile       = get_bits(&s->gb, 3);
1404     s->avctx->level         = get_bits(&s->gb, 4);
1405     s->progressive_sequence = get_bits1(&s->gb);   /* progressive_sequence */
1406     s->chroma_format        = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1407
1408     if (!s->chroma_format) {
1409         s->chroma_format = 1;
1410         av_log(s->avctx, AV_LOG_WARNING, "Chroma format invalid\n");
1411     }
1412
1413     horiz_size_ext          = get_bits(&s->gb, 2);
1414     vert_size_ext           = get_bits(&s->gb, 2);
1415     s->width  |= (horiz_size_ext << 12);
1416     s->height |= (vert_size_ext  << 12);
1417     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1418     s->bit_rate += (bit_rate_ext << 18) * 400LL;
1419     check_marker(s->avctx, &s->gb, "after bit rate extension");
1420     s->avctx->rc_buffer_size += get_bits(&s->gb, 8) * 1024 * 16 << 10;
1421
1422     s->low_delay = get_bits1(&s->gb);
1423     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
1424         s->low_delay = 1;
1425
1426     s1->frame_rate_ext.num = get_bits(&s->gb, 2) + 1;
1427     s1->frame_rate_ext.den = get_bits(&s->gb, 5) + 1;
1428
1429     ff_dlog(s->avctx, "sequence extension\n");
1430     s->codec_id = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
1431
1432     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1433         av_log(s->avctx, AV_LOG_DEBUG,
1434                "profile: %d, level: %d ps: %d cf:%d vbv buffer: %d, bitrate:%"PRId64"\n",
1435                s->avctx->profile, s->avctx->level, s->progressive_sequence, s->chroma_format,
1436                s->avctx->rc_buffer_size, s->bit_rate);
1437 }
1438
1439 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1440 {
1441     MpegEncContext *s = &s1->mpeg_enc_ctx;
1442     int color_description, w, h;
1443
1444     skip_bits(&s->gb, 3); /* video format */
1445     color_description = get_bits1(&s->gb);
1446     if (color_description) {
1447         s->avctx->color_primaries = get_bits(&s->gb, 8);
1448         s->avctx->color_trc       = get_bits(&s->gb, 8);
1449         s->avctx->colorspace      = get_bits(&s->gb, 8);
1450     }
1451     w = get_bits(&s->gb, 14);
1452     skip_bits(&s->gb, 1); // marker
1453     h = get_bits(&s->gb, 14);
1454     // remaining 3 bits are zero padding
1455
1456     s1->pan_scan.width  = 16 * w;
1457     s1->pan_scan.height = 16 * h;
1458
1459     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1460         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1461 }
1462
1463 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1464 {
1465     MpegEncContext *s = &s1->mpeg_enc_ctx;
1466     int i, nofco;
1467
1468     nofco = 1;
1469     if (s->progressive_sequence) {
1470         if (s->repeat_first_field) {
1471             nofco++;
1472             if (s->top_field_first)
1473                 nofco++;
1474         }
1475     } else {
1476         if (s->picture_structure == PICT_FRAME) {
1477             nofco++;
1478             if (s->repeat_first_field)
1479                 nofco++;
1480         }
1481     }
1482     for (i = 0; i < nofco; i++) {
1483         s1->pan_scan.position[i][0] = get_sbits(&s->gb, 16);
1484         skip_bits(&s->gb, 1); // marker
1485         s1->pan_scan.position[i][1] = get_sbits(&s->gb, 16);
1486         skip_bits(&s->gb, 1); // marker
1487     }
1488
1489     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1490         av_log(s->avctx, AV_LOG_DEBUG,
1491                "pde (%"PRId16",%"PRId16") (%"PRId16",%"PRId16") (%"PRId16",%"PRId16")\n",
1492                s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1493                s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1494                s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]);
1495 }
1496
1497 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64],
1498                        uint16_t matrix1[64], int intra)
1499 {
1500     int i;
1501
1502     for (i = 0; i < 64; i++) {
1503         int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1504         int v = get_bits(&s->gb, 8);
1505         if (v == 0) {
1506             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1507             return AVERROR_INVALIDDATA;
1508         }
1509         if (intra && i == 0 && v != 8) {
1510             av_log(s->avctx, AV_LOG_DEBUG, "intra matrix specifies invalid DC quantizer %d, ignoring\n", v);
1511             v = 8; // needed by pink.mpg / issue1046
1512         }
1513         matrix0[j] = v;
1514         if (matrix1)
1515             matrix1[j] = v;
1516     }
1517     return 0;
1518 }
1519
1520 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1521 {
1522     ff_dlog(s->avctx, "matrix extension\n");
1523
1524     if (get_bits1(&s->gb))
1525         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1526     if (get_bits1(&s->gb))
1527         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1528     if (get_bits1(&s->gb))
1529         load_matrix(s, s->chroma_intra_matrix, NULL, 1);
1530     if (get_bits1(&s->gb))
1531         load_matrix(s, s->chroma_inter_matrix, NULL, 0);
1532 }
1533
1534 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1535 {
1536     MpegEncContext *s = &s1->mpeg_enc_ctx;
1537
1538     s->full_pel[0]       = s->full_pel[1] = 0;
1539     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1540     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1541     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1542     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1543     if (!s->pict_type && s1->mpeg_enc_ctx_allocated) {
1544         av_log(s->avctx, AV_LOG_ERROR,
1545                "Missing picture start code, guessing missing values\n");
1546         if (s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1] == 15) {
1547             if (s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1548                 s->pict_type = AV_PICTURE_TYPE_I;
1549             else
1550                 s->pict_type = AV_PICTURE_TYPE_P;
1551         } else
1552             s->pict_type = AV_PICTURE_TYPE_B;
1553         s->current_picture.f->pict_type = s->pict_type;
1554         s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1555     }
1556     s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0];
1557     s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1];
1558     s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0];
1559     s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1];
1560
1561     s->intra_dc_precision         = get_bits(&s->gb, 2);
1562     s->picture_structure          = get_bits(&s->gb, 2);
1563     s->top_field_first            = get_bits1(&s->gb);
1564     s->frame_pred_frame_dct       = get_bits1(&s->gb);
1565     s->concealment_motion_vectors = get_bits1(&s->gb);
1566     s->q_scale_type               = get_bits1(&s->gb);
1567     s->intra_vlc_format           = get_bits1(&s->gb);
1568     s->alternate_scan             = get_bits1(&s->gb);
1569     s->repeat_first_field         = get_bits1(&s->gb);
1570     s->chroma_420_type            = get_bits1(&s->gb);
1571     s->progressive_frame          = get_bits1(&s->gb);
1572
1573     if (s->alternate_scan) {
1574         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
1575         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
1576     } else {
1577         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
1578         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
1579     }
1580
1581     /* composite display not parsed */
1582     ff_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1583     ff_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
1584     ff_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
1585     ff_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1586     ff_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1587     ff_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1588     ff_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1589     ff_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1590     ff_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1591 }
1592
1593 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size)
1594 {
1595     AVCodecContext *avctx = s->avctx;
1596     Mpeg1Context *s1      = (Mpeg1Context *) s;
1597     int ret;
1598
1599     /* start frame decoding */
1600     if (s->first_field || s->picture_structure == PICT_FRAME) {
1601         AVFrameSideData *pan_scan;
1602
1603         if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
1604             return ret;
1605
1606         ff_mpeg_er_frame_start(s);
1607
1608         /* first check if we must repeat the frame */
1609         s->current_picture_ptr->f->repeat_pict = 0;
1610         if (s->repeat_first_field) {
1611             if (s->progressive_sequence) {
1612                 if (s->top_field_first)
1613                     s->current_picture_ptr->f->repeat_pict = 4;
1614                 else
1615                     s->current_picture_ptr->f->repeat_pict = 2;
1616             } else if (s->progressive_frame) {
1617                 s->current_picture_ptr->f->repeat_pict = 1;
1618             }
1619         }
1620
1621         pan_scan = av_frame_new_side_data(s->current_picture_ptr->f,
1622                                           AV_FRAME_DATA_PANSCAN,
1623                                           sizeof(s1->pan_scan));
1624         if (!pan_scan)
1625             return AVERROR(ENOMEM);
1626         memcpy(pan_scan->data, &s1->pan_scan, sizeof(s1->pan_scan));
1627
1628         if (s1->a53_caption) {
1629             AVFrameSideData *sd = av_frame_new_side_data(
1630                 s->current_picture_ptr->f, AV_FRAME_DATA_A53_CC,
1631                 s1->a53_caption_size);
1632             if (sd)
1633                 memcpy(sd->data, s1->a53_caption, s1->a53_caption_size);
1634             av_freep(&s1->a53_caption);
1635         }
1636
1637         if (s1->has_stereo3d) {
1638             AVStereo3D *stereo = av_stereo3d_create_side_data(s->current_picture_ptr->f);
1639             if (!stereo)
1640                 return AVERROR(ENOMEM);
1641
1642             *stereo = s1->stereo3d;
1643             s1->has_stereo3d = 0;
1644         }
1645
1646         if (s1->has_afd) {
1647             AVFrameSideData *sd =
1648                 av_frame_new_side_data(s->current_picture_ptr->f,
1649                                        AV_FRAME_DATA_AFD, 1);
1650             if (!sd)
1651                 return AVERROR(ENOMEM);
1652
1653             *sd->data   = s1->afd;
1654             s1->has_afd = 0;
1655         }
1656
1657         if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_FRAME))
1658             ff_thread_finish_setup(avctx);
1659     } else { // second field
1660         int i;
1661
1662         if (!s->current_picture_ptr) {
1663             av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1664             return AVERROR_INVALIDDATA;
1665         }
1666
1667         if (s->avctx->hwaccel &&
1668             (s->avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
1669             if ((ret = s->avctx->hwaccel->end_frame(s->avctx)) < 0) {
1670                 av_log(avctx, AV_LOG_ERROR,
1671                        "hardware accelerator failed to decode first field\n");
1672                 return ret;
1673             }
1674         }
1675
1676         for (i = 0; i < 4; i++) {
1677             s->current_picture.f->data[i] = s->current_picture_ptr->f->data[i];
1678             if (s->picture_structure == PICT_BOTTOM_FIELD)
1679                 s->current_picture.f->data[i] +=
1680                     s->current_picture_ptr->f->linesize[i];
1681         }
1682     }
1683
1684     if (avctx->hwaccel) {
1685         if ((ret = avctx->hwaccel->start_frame(avctx, buf, buf_size)) < 0)
1686             return ret;
1687     }
1688
1689     return 0;
1690 }
1691
1692 #define DECODE_SLICE_ERROR -1
1693 #define DECODE_SLICE_OK     0
1694
1695 /**
1696  * Decode a slice.
1697  * MpegEncContext.mb_y must be set to the MB row from the startcode.
1698  * @return DECODE_SLICE_ERROR if the slice is damaged,
1699  *         DECODE_SLICE_OK if this slice is OK
1700  */
1701 static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
1702                              const uint8_t **buf, int buf_size)
1703 {
1704     AVCodecContext *avctx = s->avctx;
1705     const int lowres      = s->avctx->lowres;
1706     const int field_pic   = s->picture_structure != PICT_FRAME;
1707     int ret;
1708
1709     s->resync_mb_x =
1710     s->resync_mb_y = -1;
1711
1712     av_assert0(mb_y < s->mb_height);
1713
1714     init_get_bits(&s->gb, *buf, buf_size * 8);
1715     if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
1716         skip_bits(&s->gb, 3);
1717
1718     ff_mpeg1_clean_buffers(s);
1719     s->interlaced_dct = 0;
1720
1721     s->qscale = mpeg_get_qscale(s);
1722
1723     if (s->qscale == 0) {
1724         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1725         return AVERROR_INVALIDDATA;
1726     }
1727
1728     /* extra slice info */
1729     if (skip_1stop_8data_bits(&s->gb) < 0)
1730         return AVERROR_INVALIDDATA;
1731
1732     s->mb_x = 0;
1733
1734     if (mb_y == 0 && s->codec_tag == AV_RL32("SLIF")) {
1735         skip_bits1(&s->gb);
1736     } else {
1737         while (get_bits_left(&s->gb) > 0) {
1738             int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1739                                 MBINCR_VLC_BITS, 2);
1740             if (code < 0) {
1741                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1742                 return AVERROR_INVALIDDATA;
1743             }
1744             if (code >= 33) {
1745                 if (code == 33)
1746                     s->mb_x += 33;
1747                 /* otherwise, stuffing, nothing to do */
1748             } else {
1749                 s->mb_x += code;
1750                 break;
1751             }
1752         }
1753     }
1754
1755     if (s->mb_x >= (unsigned) s->mb_width) {
1756         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1757         return AVERROR_INVALIDDATA;
1758     }
1759
1760     if (avctx->hwaccel && avctx->hwaccel->decode_slice) {
1761         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1762         int start_code = -1;
1763         buf_end = avpriv_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1764         if (buf_end < *buf + buf_size)
1765             buf_end -= 4;
1766         s->mb_y = mb_y;
1767         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1768             return DECODE_SLICE_ERROR;
1769         *buf = buf_end;
1770         return DECODE_SLICE_OK;
1771     }
1772
1773     s->resync_mb_x = s->mb_x;
1774     s->resync_mb_y = s->mb_y = mb_y;
1775     s->mb_skip_run = 0;
1776     ff_init_block_index(s);
1777
1778     if (s->mb_y == 0 && s->mb_x == 0 && (s->first_field || s->picture_structure == PICT_FRAME)) {
1779         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
1780             av_log(s->avctx, AV_LOG_DEBUG,
1781                    "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",
1782                    s->qscale,
1783                    s->mpeg_f_code[0][0], s->mpeg_f_code[0][1],
1784                    s->mpeg_f_code[1][0], s->mpeg_f_code[1][1],
1785                    s->pict_type  == AV_PICTURE_TYPE_I ? "I" :
1786                    (s->pict_type == AV_PICTURE_TYPE_P ? "P" :
1787                    (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
1788                    s->progressive_sequence ? "ps"  : "",
1789                    s->progressive_frame    ? "pf"  : "",
1790                    s->alternate_scan       ? "alt" : "",
1791                    s->top_field_first      ? "top" : "",
1792                    s->intra_dc_precision, s->picture_structure,
1793                    s->frame_pred_frame_dct, s->concealment_motion_vectors,
1794                    s->q_scale_type, s->intra_vlc_format,
1795                    s->repeat_first_field, s->chroma_420_type ? "420" : "");
1796         }
1797     }
1798
1799     for (;;) {
1800         // If 1, we memcpy blocks in xvmcvideo.
1801         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1802             ff_xvmc_init_block(s); // set s->block
1803
1804         if ((ret = mpeg_decode_mb(s, s->block)) < 0)
1805             return ret;
1806
1807         // Note motion_val is normally NULL unless we want to extract the MVs.
1808         if (s->current_picture.motion_val[0] && !s->encoding) {
1809             const int wrap = s->b8_stride;
1810             int xy         = s->mb_x * 2 + s->mb_y * 2 * wrap;
1811             int b8_xy      = 4 * (s->mb_x + s->mb_y * s->mb_stride);
1812             int motion_x, motion_y, dir, i;
1813
1814             for (i = 0; i < 2; i++) {
1815                 for (dir = 0; dir < 2; dir++) {
1816                     if (s->mb_intra ||
1817                         (dir == 1 && s->pict_type != AV_PICTURE_TYPE_B)) {
1818                         motion_x = motion_y = 0;
1819                     } else if (s->mv_type == MV_TYPE_16X16 ||
1820                                (s->mv_type == MV_TYPE_FIELD && field_pic)) {
1821                         motion_x = s->mv[dir][0][0];
1822                         motion_y = s->mv[dir][0][1];
1823                     } else { /* if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8)) */
1824                         motion_x = s->mv[dir][i][0];
1825                         motion_y = s->mv[dir][i][1];
1826                     }
1827
1828                     s->current_picture.motion_val[dir][xy][0]     = motion_x;
1829                     s->current_picture.motion_val[dir][xy][1]     = motion_y;
1830                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1831                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1832                     s->current_picture.ref_index [dir][b8_xy]     =
1833                     s->current_picture.ref_index [dir][b8_xy + 1] = s->field_select[dir][i];
1834                     av_assert2(s->field_select[dir][i] == 0 ||
1835                                s->field_select[dir][i] == 1);
1836                 }
1837                 xy    += wrap;
1838                 b8_xy += 2;
1839             }
1840         }
1841
1842         s->dest[0] += 16 >> lowres;
1843         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1844         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1845
1846         ff_mpv_reconstruct_mb(s, s->block);
1847
1848         if (++s->mb_x >= s->mb_width) {
1849             const int mb_size = 16 >> s->avctx->lowres;
1850             int left;
1851
1852             ff_mpeg_draw_horiz_band(s, mb_size * (s->mb_y >> field_pic), mb_size);
1853             ff_mpv_report_decode_progress(s);
1854
1855             s->mb_x  = 0;
1856             s->mb_y += 1 << field_pic;
1857
1858             if (s->mb_y >= s->mb_height) {
1859                 int left   = get_bits_left(&s->gb);
1860                 int is_d10 = s->chroma_format == 2 &&
1861                              s->pict_type == AV_PICTURE_TYPE_I &&
1862                              avctx->profile == 0 && avctx->level == 5 &&
1863                              s->intra_dc_precision == 2 &&
1864                              s->q_scale_type == 1 && s->alternate_scan == 0 &&
1865                              s->progressive_frame == 0
1866                              /* vbv_delay == 0xBBB || 0xE10 */;
1867
1868                 if (left >= 32 && !is_d10) {
1869                     GetBitContext gb = s->gb;
1870                     align_get_bits(&gb);
1871                     if (show_bits(&gb, 24) == 0x060E2B) {
1872                         av_log(avctx, AV_LOG_DEBUG, "Invalid MXF data found in video stream\n");
1873                         is_d10 = 1;
1874                     }
1875                     if (left > 32 && show_bits_long(&gb, 32) == 0x201) {
1876                         av_log(avctx, AV_LOG_DEBUG, "skipping m704 alpha (unsupported)\n");
1877                         goto eos;
1878                     }
1879                 }
1880
1881                 if (left < 0 ||
1882                     (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10) ||
1883                     ((avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE)) && left > 8)) {
1884                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X at %d %d\n",
1885                            left, left>0 ? show_bits(&s->gb, FFMIN(left, 23)) : 0, s->mb_x, s->mb_y);
1886                     return AVERROR_INVALIDDATA;
1887                 } else
1888                     goto eos;
1889             }
1890             // There are some files out there which are missing the last slice
1891             // in cases where the slice is completely outside the visible
1892             // area, we detect this here instead of running into the end expecting
1893             // more data
1894             left = get_bits_left(&s->gb);
1895             if (s->mb_y >= ((s->height + 15) >> 4) &&
1896                 !s->progressive_sequence &&
1897                 left <= 25 &&
1898                 left >= 0 &&
1899                 s->mb_skip_run == -1 &&
1900                 (!left || show_bits(&s->gb, left) == 0))
1901                 goto eos;
1902
1903             ff_init_block_index(s);
1904         }
1905
1906         /* skip mb handling */
1907         if (s->mb_skip_run == -1) {
1908             /* read increment again */
1909             s->mb_skip_run = 0;
1910             for (;;) {
1911                 int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1912                                     MBINCR_VLC_BITS, 2);
1913                 if (code < 0) {
1914                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1915                     return AVERROR_INVALIDDATA;
1916                 }
1917                 if (code >= 33) {
1918                     if (code == 33) {
1919                         s->mb_skip_run += 33;
1920                     } else if (code == 35) {
1921                         if (s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0) {
1922                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1923                             return AVERROR_INVALIDDATA;
1924                         }
1925                         goto eos; /* end of slice */
1926                     }
1927                     /* otherwise, stuffing, nothing to do */
1928                 } else {
1929                     s->mb_skip_run += code;
1930                     break;
1931                 }
1932             }
1933             if (s->mb_skip_run) {
1934                 int i;
1935                 if (s->pict_type == AV_PICTURE_TYPE_I) {
1936                     av_log(s->avctx, AV_LOG_ERROR,
1937                            "skipped MB in I-frame at %d %d\n", s->mb_x, s->mb_y);
1938                     return AVERROR_INVALIDDATA;
1939                 }
1940
1941                 /* skip mb */
1942                 s->mb_intra = 0;
1943                 for (i = 0; i < 12; i++)
1944                     s->block_last_index[i] = -1;
1945                 if (s->picture_structure == PICT_FRAME)
1946                     s->mv_type = MV_TYPE_16X16;
1947                 else
1948                     s->mv_type = MV_TYPE_FIELD;
1949                 if (s->pict_type == AV_PICTURE_TYPE_P) {
1950                     /* if P type, zero motion vector is implied */
1951                     s->mv_dir             = MV_DIR_FORWARD;
1952                     s->mv[0][0][0]        = s->mv[0][0][1]      = 0;
1953                     s->last_mv[0][0][0]   = s->last_mv[0][0][1] = 0;
1954                     s->last_mv[0][1][0]   = s->last_mv[0][1][1] = 0;
1955                     s->field_select[0][0] = (s->picture_structure - 1) & 1;
1956                 } else {
1957                     /* if B type, reuse previous vectors and directions */
1958                     s->mv[0][0][0] = s->last_mv[0][0][0];
1959                     s->mv[0][0][1] = s->last_mv[0][0][1];
1960                     s->mv[1][0][0] = s->last_mv[1][0][0];
1961                     s->mv[1][0][1] = s->last_mv[1][0][1];
1962                     s->field_select[0][0] = (s->picture_structure - 1) & 1;
1963                     s->field_select[1][0] = (s->picture_structure - 1) & 1;
1964                 }
1965             }
1966         }
1967     }
1968 eos: // end of slice
1969     if (get_bits_left(&s->gb) < 0) {
1970         av_log(s, AV_LOG_ERROR, "overread %d\n", -get_bits_left(&s->gb));
1971         return AVERROR_INVALIDDATA;
1972     }
1973     *buf += (get_bits_count(&s->gb) - 1) / 8;
1974     ff_dlog(s, "Slice start:%d %d  end:%d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1975     return 0;
1976 }
1977
1978 static int slice_decode_thread(AVCodecContext *c, void *arg)
1979 {
1980     MpegEncContext *s   = *(void **) arg;
1981     const uint8_t *buf  = s->gb.buffer;
1982     int mb_y            = s->start_mb_y;
1983     const int field_pic = s->picture_structure != PICT_FRAME;
1984
1985     s->er.error_count = (3 * (s->end_mb_y - s->start_mb_y) * s->mb_width) >> field_pic;
1986
1987     for (;;) {
1988         uint32_t start_code;
1989         int ret;
1990
1991         ret = mpeg_decode_slice(s, mb_y, &buf, s->gb.buffer_end - buf);
1992         emms_c();
1993         ff_dlog(c, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1994                 ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y,
1995                 s->start_mb_y, s->end_mb_y, s->er.error_count);
1996         if (ret < 0) {
1997             if (c->err_recognition & AV_EF_EXPLODE)
1998                 return ret;
1999             if (s->resync_mb_x >= 0 && s->resync_mb_y >= 0)
2000                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2001                                 s->mb_x, s->mb_y,
2002                                 ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2003         } else {
2004             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2005                             s->mb_x - 1, s->mb_y,
2006                             ER_AC_END | ER_DC_END | ER_MV_END);
2007         }
2008
2009         if (s->mb_y == s->end_mb_y)
2010             return 0;
2011
2012         start_code = -1;
2013         buf        = avpriv_find_start_code(buf, s->gb.buffer_end, &start_code);
2014         mb_y       = start_code - SLICE_MIN_START_CODE;
2015         if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
2016             mb_y += (*buf&0xE0)<<2;
2017         mb_y <<= field_pic;
2018         if (s->picture_structure == PICT_BOTTOM_FIELD)
2019             mb_y++;
2020         if (mb_y < 0 || mb_y >= s->end_mb_y)
2021             return AVERROR_INVALIDDATA;
2022     }
2023 }
2024
2025 /**
2026  * Handle slice ends.
2027  * @return 1 if it seems to be the last slice
2028  */
2029 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
2030 {
2031     Mpeg1Context *s1  = avctx->priv_data;
2032     MpegEncContext *s = &s1->mpeg_enc_ctx;
2033
2034     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
2035         return 0;
2036
2037     if (s->avctx->hwaccel) {
2038         int ret = s->avctx->hwaccel->end_frame(s->avctx);
2039         if (ret < 0) {
2040             av_log(avctx, AV_LOG_ERROR,
2041                    "hardware accelerator failed to decode picture\n");
2042             return ret;
2043         }
2044     }
2045
2046     /* end of slice reached */
2047     if (/* s->mb_y << field_pic == s->mb_height && */ !s->first_field && !s1->first_slice) {
2048         /* end of image */
2049
2050         ff_er_frame_end(&s->er);
2051
2052         ff_mpv_frame_end(s);
2053
2054         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
2055             int ret = av_frame_ref(pict, s->current_picture_ptr->f);
2056             if (ret < 0)
2057                 return ret;
2058             ff_print_debug_info(s, s->current_picture_ptr, pict);
2059             ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2060         } else {
2061             if (avctx->active_thread_type & FF_THREAD_FRAME)
2062                 s->picture_number++;
2063             /* latency of 1 frame for I- and P-frames */
2064             /* XXX: use another variable than picture_number */
2065             if (s->last_picture_ptr) {
2066                 int ret = av_frame_ref(pict, s->last_picture_ptr->f);
2067                 if (ret < 0)
2068                     return ret;
2069                 ff_print_debug_info(s, s->last_picture_ptr, pict);
2070                 ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2071             }
2072         }
2073
2074         return 1;
2075     } else {
2076         return 0;
2077     }
2078 }
2079
2080 static int mpeg1_decode_sequence(AVCodecContext *avctx,
2081                                  const uint8_t *buf, int buf_size)
2082 {
2083     Mpeg1Context *s1  = avctx->priv_data;
2084     MpegEncContext *s = &s1->mpeg_enc_ctx;
2085     int width, height;
2086     int i, v, j;
2087
2088     init_get_bits(&s->gb, buf, buf_size * 8);
2089
2090     width  = get_bits(&s->gb, 12);
2091     height = get_bits(&s->gb, 12);
2092     if (width == 0 || height == 0) {
2093         av_log(avctx, AV_LOG_WARNING,
2094                "Invalid horizontal or vertical size value.\n");
2095         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2096             return AVERROR_INVALIDDATA;
2097     }
2098     s->aspect_ratio_info = get_bits(&s->gb, 4);
2099     if (s->aspect_ratio_info == 0) {
2100         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
2101         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2102             return AVERROR_INVALIDDATA;
2103     }
2104     s->frame_rate_index = get_bits(&s->gb, 4);
2105     if (s->frame_rate_index == 0 || s->frame_rate_index > 13) {
2106         av_log(avctx, AV_LOG_WARNING,
2107                "frame_rate_index %d is invalid\n", s->frame_rate_index);
2108         s->frame_rate_index = 1;
2109     }
2110     s->bit_rate = get_bits(&s->gb, 18) * 400LL;
2111     if (check_marker(s->avctx, &s->gb, "in sequence header") == 0) {
2112         return AVERROR_INVALIDDATA;
2113     }
2114
2115     s->avctx->rc_buffer_size = get_bits(&s->gb, 10) * 1024 * 16;
2116     skip_bits(&s->gb, 1);
2117
2118     /* get matrix */
2119     if (get_bits1(&s->gb)) {
2120         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2121     } else {
2122         for (i = 0; i < 64; i++) {
2123             j = s->idsp.idct_permutation[i];
2124             v = ff_mpeg1_default_intra_matrix[i];
2125             s->intra_matrix[j]        = v;
2126             s->chroma_intra_matrix[j] = v;
2127         }
2128     }
2129     if (get_bits1(&s->gb)) {
2130         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2131     } else {
2132         for (i = 0; i < 64; i++) {
2133             int j = s->idsp.idct_permutation[i];
2134             v = ff_mpeg1_default_non_intra_matrix[i];
2135             s->inter_matrix[j]        = v;
2136             s->chroma_inter_matrix[j] = v;
2137         }
2138     }
2139
2140     if (show_bits(&s->gb, 23) != 0) {
2141         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2142         return AVERROR_INVALIDDATA;
2143     }
2144
2145     s->width  = width;
2146     s->height = height;
2147
2148     /* We set MPEG-2 parameters so that it emulates MPEG-1. */
2149     s->progressive_sequence = 1;
2150     s->progressive_frame    = 1;
2151     s->picture_structure    = PICT_FRAME;
2152     s->first_field          = 0;
2153     s->frame_pred_frame_dct = 1;
2154     s->chroma_format        = 1;
2155     s->codec_id             =
2156     s->avctx->codec_id      = AV_CODEC_ID_MPEG1VIDEO;
2157     s->out_format           = FMT_MPEG1;
2158     s->swap_uv              = 0; // AFAIK VCR2 does not have SEQ_HEADER
2159     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
2160         s->low_delay = 1;
2161
2162     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2163         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%"PRId64", aspect_ratio_info: %d \n",
2164                s->avctx->rc_buffer_size, s->bit_rate, s->aspect_ratio_info);
2165
2166     return 0;
2167 }
2168
2169 static int vcr2_init_sequence(AVCodecContext *avctx)
2170 {
2171     Mpeg1Context *s1  = avctx->priv_data;
2172     MpegEncContext *s = &s1->mpeg_enc_ctx;
2173     int i, v, ret;
2174
2175     /* start new MPEG-1 context decoding */
2176     s->out_format = FMT_MPEG1;
2177     if (s1->mpeg_enc_ctx_allocated) {
2178         ff_mpv_common_end(s);
2179         s1->mpeg_enc_ctx_allocated = 0;
2180     }
2181     s->width            = avctx->coded_width;
2182     s->height           = avctx->coded_height;
2183     avctx->has_b_frames = 0; // true?
2184     s->low_delay        = 1;
2185
2186     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2187     setup_hwaccel_for_pixfmt(avctx);
2188
2189     ff_mpv_idct_init(s);
2190     if ((ret = ff_mpv_common_init(s)) < 0)
2191         return ret;
2192     s1->mpeg_enc_ctx_allocated = 1;
2193
2194     for (i = 0; i < 64; i++) {
2195         int j = s->idsp.idct_permutation[i];
2196         v = ff_mpeg1_default_intra_matrix[i];
2197         s->intra_matrix[j]        = v;
2198         s->chroma_intra_matrix[j] = v;
2199
2200         v = ff_mpeg1_default_non_intra_matrix[i];
2201         s->inter_matrix[j]        = v;
2202         s->chroma_inter_matrix[j] = v;
2203     }
2204
2205     s->progressive_sequence  = 1;
2206     s->progressive_frame     = 1;
2207     s->picture_structure     = PICT_FRAME;
2208     s->first_field           = 0;
2209     s->frame_pred_frame_dct  = 1;
2210     s->chroma_format         = 1;
2211     if (s->codec_tag == AV_RL32("BW10")) {
2212         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
2213     } else {
2214         s->swap_uv = 1; // in case of xvmc we need to swap uv for each MB
2215         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
2216     }
2217     s1->save_width           = s->width;
2218     s1->save_height          = s->height;
2219     s1->save_progressive_seq = s->progressive_sequence;
2220     return 0;
2221 }
2222
2223 static int mpeg_decode_a53_cc(AVCodecContext *avctx,
2224                               const uint8_t *p, int buf_size)
2225 {
2226     Mpeg1Context *s1 = avctx->priv_data;
2227
2228     if (buf_size >= 6 &&
2229         p[0] == 'G' && p[1] == 'A' && p[2] == '9' && p[3] == '4' &&
2230         p[4] == 3 && (p[5] & 0x40)) {
2231         /* extract A53 Part 4 CC data */
2232         int cc_count = p[5] & 0x1f;
2233         if (cc_count > 0 && buf_size >= 7 + cc_count * 3) {
2234             av_freep(&s1->a53_caption);
2235             s1->a53_caption_size = cc_count * 3;
2236             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2237             if (!s1->a53_caption) {
2238                 s1->a53_caption_size = 0;
2239             } else {
2240                 memcpy(s1->a53_caption, p + 7, s1->a53_caption_size);
2241             }
2242             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
2243         }
2244         return 1;
2245     } else if (buf_size >= 2 &&
2246                p[0] == 0x03 && (p[1]&0x7f) == 0x01) {
2247         /* extract SCTE-20 CC data */
2248         GetBitContext gb;
2249         int cc_count = 0;
2250         int i;
2251
2252         init_get_bits(&gb, p + 2, buf_size - 2);
2253         cc_count = get_bits(&gb, 5);
2254         if (cc_count > 0) {
2255             av_freep(&s1->a53_caption);
2256             s1->a53_caption_size = cc_count * 3;
2257             s1->a53_caption      = av_mallocz(s1->a53_caption_size);
2258             if (!s1->a53_caption) {
2259                 s1->a53_caption_size = 0;
2260             } else {
2261                 uint8_t field, cc1, cc2;
2262                 uint8_t *cap = s1->a53_caption;
2263                 for (i = 0; i < cc_count && get_bits_left(&gb) >= 26; i++) {
2264                     skip_bits(&gb, 2); // priority
2265                     field = get_bits(&gb, 2);
2266                     skip_bits(&gb, 5); // line_offset
2267                     cc1 = get_bits(&gb, 8);
2268                     cc2 = get_bits(&gb, 8);
2269                     skip_bits(&gb, 1); // marker
2270
2271                     if (!field) { // forbidden
2272                         cap[0] = cap[1] = cap[2] = 0x00;
2273                     } else {
2274                         field = (field == 2 ? 1 : 0);
2275                         if (!s1->mpeg_enc_ctx.top_field_first) field = !field;
2276                         cap[0] = 0x04 | field;
2277                         cap[1] = ff_reverse[cc1];
2278                         cap[2] = ff_reverse[cc2];
2279                     }
2280                     cap += 3;
2281                 }
2282             }
2283             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
2284         }
2285         return 1;
2286     } else if (buf_size >= 11 &&
2287                p[0] == 'C' && p[1] == 'C' && p[2] == 0x01 && p[3] == 0xf8) {
2288         /* extract DVD CC data
2289          *
2290          * uint32_t   user_data_start_code        0x000001B2    (big endian)
2291          * uint16_t   user_identifier             0x4343 "CC"
2292          * uint8_t    user_data_type_code         0x01
2293          * uint8_t    caption_block_size          0xF8
2294          * uint8_t
2295          *   bit 7    caption_odd_field_first     1=odd field (CC1/CC2) first  0=even field (CC3/CC4) first
2296          *   bit 6    caption_filler              0
2297          *   bit 5:1  caption_block_count         number of caption blocks (pairs of caption words = frames). Most DVDs use 15 per start of GOP.
2298          *   bit 0    caption_extra_field_added   1=one additional caption word
2299          *
2300          * struct caption_field_block {
2301          *   uint8_t
2302          *     bit 7:1 caption_filler             0x7F (all 1s)
2303          *     bit 0   caption_field_odd          1=odd field (this is CC1/CC2)  0=even field (this is CC3/CC4)
2304          *   uint8_t   caption_first_byte
2305          *   uint8_t   caption_second_byte
2306          * } caption_block[(caption_block_count * 2) + caption_extra_field_added];
2307          *
2308          * Some DVDs encode caption data for both fields with caption_field_odd=1. The only way to decode the fields
2309          * correctly is to start on the field indicated by caption_odd_field_first and count between odd/even fields.
2310          * Don't assume that the first caption word is the odd field. There do exist MPEG files in the wild that start
2311          * on the even field. There also exist DVDs in the wild that encode an odd field count and the
2312          * caption_extra_field_added/caption_odd_field_first bits change per packet to allow that. */
2313         int cc_count = 0;
2314         int i;
2315         // There is a caption count field in the data, but it is often
2316         // incorrect.  So count the number of captions present.
2317         for (i = 5; i + 6 <= buf_size && ((p[i] & 0xfe) == 0xfe); i += 6)
2318             cc_count++;
2319         // Transform the DVD format into A53 Part 4 format
2320         if (cc_count > 0) {
2321             av_freep(&s1->a53_caption);
2322             s1->a53_caption_size = cc_count * 6;
2323             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2324             if (!s1->a53_caption) {
2325                 s1->a53_caption_size = 0;
2326             } else {
2327                 uint8_t field1 = !!(p[4] & 0x80);
2328                 uint8_t *cap = s1->a53_caption;
2329                 p += 5;
2330                 for (i = 0; i < cc_count; i++) {
2331                     cap[0] = (p[0] == 0xff && field1) ? 0xfc : 0xfd;
2332                     cap[1] = p[1];
2333                     cap[2] = p[2];
2334                     cap[3] = (p[3] == 0xff && !field1) ? 0xfc : 0xfd;
2335                     cap[4] = p[4];
2336                     cap[5] = p[5];
2337                     cap += 6;
2338                     p += 6;
2339                 }
2340             }
2341             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
2342         }
2343         return 1;
2344     }
2345     return 0;
2346 }
2347
2348 static void mpeg_decode_user_data(AVCodecContext *avctx,
2349                                   const uint8_t *p, int buf_size)
2350 {
2351     Mpeg1Context *s = avctx->priv_data;
2352     const uint8_t *buf_end = p + buf_size;
2353     Mpeg1Context *s1 = avctx->priv_data;
2354
2355 #if 0
2356     int i;
2357     for(i=0; !(!p[i-2] && !p[i-1] && p[i]==1) && i<buf_size; i++){
2358         av_log(avctx, AV_LOG_ERROR, "%c", p[i]);
2359     }
2360     av_log(avctx, AV_LOG_ERROR, "\n");
2361 #endif
2362
2363     if (buf_size > 29){
2364         int i;
2365         for(i=0; i<20; i++)
2366             if (!memcmp(p+i, "\0TMPGEXS\0", 9)){
2367                 s->tmpgexs= 1;
2368             }
2369     }
2370     /* we parse the DTG active format information */
2371     if (buf_end - p >= 5 &&
2372         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2373         int flags = p[4];
2374         p += 5;
2375         if (flags & 0x80) {
2376             /* skip event id */
2377             p += 2;
2378         }
2379         if (flags & 0x40) {
2380             if (buf_end - p < 1)
2381                 return;
2382             s1->has_afd = 1;
2383             s1->afd     = p[0] & 0x0f;
2384         }
2385     } else if (buf_end - p >= 6 &&
2386                p[0] == 'J' && p[1] == 'P' && p[2] == '3' && p[3] == 'D' &&
2387                p[4] == 0x03) { // S3D_video_format_length
2388         // the 0x7F mask ignores the reserved_bit value
2389         const uint8_t S3D_video_format_type = p[5] & 0x7F;
2390
2391         if (S3D_video_format_type == 0x03 ||
2392             S3D_video_format_type == 0x04 ||
2393             S3D_video_format_type == 0x08 ||
2394             S3D_video_format_type == 0x23) {
2395
2396             s1->has_stereo3d = 1;
2397
2398             switch (S3D_video_format_type) {
2399             case 0x03:
2400                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE;
2401                 break;
2402             case 0x04:
2403                 s1->stereo3d.type = AV_STEREO3D_TOPBOTTOM;
2404                 break;
2405             case 0x08:
2406                 s1->stereo3d.type = AV_STEREO3D_2D;
2407                 break;
2408             case 0x23:
2409                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
2410                 break;
2411             }
2412         }
2413     } else if (mpeg_decode_a53_cc(avctx, p, buf_size)) {
2414         return;
2415     }
2416 }
2417
2418 static void mpeg_decode_gop(AVCodecContext *avctx,
2419                             const uint8_t *buf, int buf_size)
2420 {
2421     Mpeg1Context *s1  = avctx->priv_data;
2422     MpegEncContext *s = &s1->mpeg_enc_ctx;
2423     int broken_link;
2424     int64_t tc;
2425
2426     init_get_bits(&s->gb, buf, buf_size * 8);
2427
2428     tc = s-> timecode_frame_start = get_bits(&s->gb, 25);
2429
2430 #if FF_API_PRIVATE_OPT
2431 FF_DISABLE_DEPRECATION_WARNINGS
2432     avctx->timecode_frame_start = tc;
2433 FF_ENABLE_DEPRECATION_WARNINGS
2434 #endif
2435
2436     s->closed_gop = get_bits1(&s->gb);
2437     /* broken_link indicates that after editing the
2438      * reference frames of the first B-Frames after GOP I-Frame
2439      * are missing (open gop) */
2440     broken_link = get_bits1(&s->gb);
2441
2442     if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2443         char tcbuf[AV_TIMECODE_STR_SIZE];
2444         av_timecode_make_mpeg_tc_string(tcbuf, tc);
2445         av_log(s->avctx, AV_LOG_DEBUG,
2446                "GOP (%s) closed_gop=%d broken_link=%d\n",
2447                tcbuf, s->closed_gop, broken_link);
2448     }
2449 }
2450
2451 static int decode_chunks(AVCodecContext *avctx, AVFrame *picture,
2452                          int *got_output, const uint8_t *buf, int buf_size)
2453 {
2454     Mpeg1Context *s = avctx->priv_data;
2455     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2456     const uint8_t *buf_ptr = buf;
2457     const uint8_t *buf_end = buf + buf_size;
2458     int ret, input_size;
2459     int last_code = 0, skip_frame = 0;
2460     int picture_start_code_seen = 0;
2461
2462     for (;;) {
2463         /* find next start code */
2464         uint32_t start_code = -1;
2465         buf_ptr = avpriv_find_start_code(buf_ptr, buf_end, &start_code);
2466         if (start_code > 0x1ff) {
2467             if (!skip_frame) {
2468                 if (HAVE_THREADS &&
2469                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2470                     !avctx->hwaccel) {
2471                     int i;
2472                     av_assert0(avctx->thread_count > 1);
2473
2474                     avctx->execute(avctx, slice_decode_thread,
2475                                    &s2->thread_context[0], NULL,
2476                                    s->slice_count, sizeof(void *));
2477                     for (i = 0; i < s->slice_count; i++)
2478                         s2->er.error_count += s2->thread_context[i]->er.error_count;
2479                 }
2480
2481                 ret = slice_end(avctx, picture);
2482                 if (ret < 0)
2483                     return ret;
2484                 else if (ret) {
2485                     // FIXME: merge with the stuff in mpeg_decode_slice
2486                     if (s2->last_picture_ptr || s2->low_delay)
2487                         *got_output = 1;
2488                 }
2489             }
2490             s2->pict_type = 0;
2491
2492             if (avctx->err_recognition & AV_EF_EXPLODE && s2->er.error_count)
2493                 return AVERROR_INVALIDDATA;
2494
2495             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2496         }
2497
2498         input_size = buf_end - buf_ptr;
2499
2500         if (avctx->debug & FF_DEBUG_STARTCODE)
2501             av_log(avctx, AV_LOG_DEBUG, "%3"PRIX32" at %"PTRDIFF_SPECIFIER" left %d\n",
2502                    start_code, buf_ptr - buf, input_size);
2503
2504         /* prepare data for next start code */
2505         switch (start_code) {
2506         case SEQ_START_CODE:
2507             if (last_code == 0) {
2508                 mpeg1_decode_sequence(avctx, buf_ptr, input_size);
2509                 if (buf != avctx->extradata)
2510                     s->sync = 1;
2511             } else {
2512                 av_log(avctx, AV_LOG_ERROR,
2513                        "ignoring SEQ_START_CODE after %X\n", last_code);
2514                 if (avctx->err_recognition & AV_EF_EXPLODE)
2515                     return AVERROR_INVALIDDATA;
2516             }
2517             break;
2518
2519         case PICTURE_START_CODE:
2520             if (picture_start_code_seen && s2->picture_structure == PICT_FRAME) {
2521                /* If it's a frame picture, there can't be more than one picture header.
2522                   Yet, it does happen and we need to handle it. */
2523                av_log(avctx, AV_LOG_WARNING, "ignoring extra picture following a frame-picture\n");
2524                break;
2525             }
2526             picture_start_code_seen = 1;
2527
2528             if (s2->width <= 0 || s2->height <= 0) {
2529                 av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d.\n",
2530                        s2->width, s2->height);
2531                 return AVERROR_INVALIDDATA;
2532             }
2533
2534             if (s->tmpgexs){
2535                 s2->intra_dc_precision= 3;
2536                 s2->intra_matrix[0]= 1;
2537             }
2538             if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) &&
2539                 !avctx->hwaccel && s->slice_count) {
2540                 int i;
2541
2542                 avctx->execute(avctx, slice_decode_thread,
2543                                s2->thread_context, NULL,
2544                                s->slice_count, sizeof(void *));
2545                 for (i = 0; i < s->slice_count; i++)
2546                     s2->er.error_count += s2->thread_context[i]->er.error_count;
2547                 s->slice_count = 0;
2548             }
2549             if (last_code == 0 || last_code == SLICE_MIN_START_CODE) {
2550                 ret = mpeg_decode_postinit(avctx);
2551                 if (ret < 0) {
2552                     av_log(avctx, AV_LOG_ERROR,
2553                            "mpeg_decode_postinit() failure\n");
2554                     return ret;
2555                 }
2556
2557                 /* We have a complete image: we try to decompress it. */
2558                 if (mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0)
2559                     s2->pict_type = 0;
2560                 s->first_slice = 1;
2561                 last_code      = PICTURE_START_CODE;
2562             } else {
2563                 av_log(avctx, AV_LOG_ERROR,
2564                        "ignoring pic after %X\n", last_code);
2565                 if (avctx->err_recognition & AV_EF_EXPLODE)
2566                     return AVERROR_INVALIDDATA;
2567             }
2568             break;
2569         case EXT_START_CODE:
2570             init_get_bits(&s2->gb, buf_ptr, input_size * 8);
2571
2572             switch (get_bits(&s2->gb, 4)) {
2573             case 0x1:
2574                 if (last_code == 0) {
2575                     mpeg_decode_sequence_extension(s);
2576                 } else {
2577                     av_log(avctx, AV_LOG_ERROR,
2578                            "ignoring seq ext after %X\n", last_code);
2579                     if (avctx->err_recognition & AV_EF_EXPLODE)
2580                         return AVERROR_INVALIDDATA;
2581                 }
2582                 break;
2583             case 0x2:
2584                 mpeg_decode_sequence_display_extension(s);
2585                 break;
2586             case 0x3:
2587                 mpeg_decode_quant_matrix_extension(s2);
2588                 break;
2589             case 0x7:
2590                 mpeg_decode_picture_display_extension(s);
2591                 break;
2592             case 0x8:
2593                 if (last_code == PICTURE_START_CODE) {
2594                     mpeg_decode_picture_coding_extension(s);
2595                 } else {
2596                     av_log(avctx, AV_LOG_ERROR,
2597                            "ignoring pic cod ext after %X\n", last_code);
2598                     if (avctx->err_recognition & AV_EF_EXPLODE)
2599                         return AVERROR_INVALIDDATA;
2600                 }
2601                 break;
2602             }
2603             break;
2604         case USER_START_CODE:
2605             mpeg_decode_user_data(avctx, buf_ptr, input_size);
2606             break;
2607         case GOP_START_CODE:
2608             if (last_code == 0) {
2609                 s2->first_field = 0;
2610                 mpeg_decode_gop(avctx, buf_ptr, input_size);
2611                 s->sync = 1;
2612             } else {
2613                 av_log(avctx, AV_LOG_ERROR,
2614                        "ignoring GOP_START_CODE after %X\n", last_code);
2615                 if (avctx->err_recognition & AV_EF_EXPLODE)
2616                     return AVERROR_INVALIDDATA;
2617             }
2618             break;
2619         default:
2620             if (start_code >= SLICE_MIN_START_CODE &&
2621                 start_code <= SLICE_MAX_START_CODE && last_code == PICTURE_START_CODE) {
2622                 if (s2->progressive_sequence && !s2->progressive_frame) {
2623                     s2->progressive_frame = 1;
2624                     av_log(s2->avctx, AV_LOG_ERROR,
2625                            "interlaced frame in progressive sequence, ignoring\n");
2626                 }
2627
2628                 if (s2->picture_structure == 0 ||
2629                     (s2->progressive_frame && s2->picture_structure != PICT_FRAME)) {
2630                     av_log(s2->avctx, AV_LOG_ERROR,
2631                            "picture_structure %d invalid, ignoring\n",
2632                            s2->picture_structure);
2633                     s2->picture_structure = PICT_FRAME;
2634                 }
2635
2636                 if (s2->progressive_sequence && !s2->frame_pred_frame_dct)
2637                     av_log(s2->avctx, AV_LOG_WARNING, "invalid frame_pred_frame_dct\n");
2638
2639                 if (s2->picture_structure == PICT_FRAME) {
2640                     s2->first_field = 0;
2641                     s2->v_edge_pos  = 16 * s2->mb_height;
2642                 } else {
2643                     s2->first_field ^= 1;
2644                     s2->v_edge_pos   = 8 * s2->mb_height;
2645                     memset(s2->mbskip_table, 0, s2->mb_stride * s2->mb_height);
2646                 }
2647             }
2648             if (start_code >= SLICE_MIN_START_CODE &&
2649                 start_code <= SLICE_MAX_START_CODE && last_code != 0) {
2650                 const int field_pic = s2->picture_structure != PICT_FRAME;
2651                 int mb_y = start_code - SLICE_MIN_START_CODE;
2652                 last_code = SLICE_MIN_START_CODE;
2653                 if (s2->codec_id != AV_CODEC_ID_MPEG1VIDEO && s2->mb_height > 2800/16)
2654                     mb_y += (*buf_ptr&0xE0)<<2;
2655
2656                 mb_y <<= field_pic;
2657                 if (s2->picture_structure == PICT_BOTTOM_FIELD)
2658                     mb_y++;
2659
2660                 if (buf_end - buf_ptr < 2) {
2661                     av_log(s2->avctx, AV_LOG_ERROR, "slice too small\n");
2662                     return AVERROR_INVALIDDATA;
2663                 }
2664
2665                 if (mb_y >= s2->mb_height) {
2666                     av_log(s2->avctx, AV_LOG_ERROR,
2667                            "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2668                     return AVERROR_INVALIDDATA;
2669                 }
2670
2671                 if (!s2->last_picture_ptr) {
2672                     /* Skip B-frames if we do not have reference frames and
2673                      * GOP is not closed. */
2674                     if (s2->pict_type == AV_PICTURE_TYPE_B) {
2675                         if (!s2->closed_gop) {
2676                             skip_frame = 1;
2677                             av_log(s2->avctx, AV_LOG_DEBUG,
2678                                    "Skipping B slice due to open GOP\n");
2679                             break;
2680                         }
2681                     }
2682                 }
2683                 if (s2->pict_type == AV_PICTURE_TYPE_I || (s2->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL))
2684                     s->sync = 1;
2685                 if (!s2->next_picture_ptr) {
2686                     /* Skip P-frames if we do not have a reference frame or
2687                      * we have an invalid header. */
2688                     if (s2->pict_type == AV_PICTURE_TYPE_P && !s->sync) {
2689                         skip_frame = 1;
2690                         av_log(s2->avctx, AV_LOG_DEBUG,
2691                                "Skipping P slice due to !sync\n");
2692                         break;
2693                     }
2694                 }
2695                 if ((avctx->skip_frame >= AVDISCARD_NONREF &&
2696                      s2->pict_type == AV_PICTURE_TYPE_B) ||
2697                     (avctx->skip_frame >= AVDISCARD_NONKEY &&
2698                      s2->pict_type != AV_PICTURE_TYPE_I) ||
2699                     avctx->skip_frame >= AVDISCARD_ALL) {
2700                     skip_frame = 1;
2701                     break;
2702                 }
2703
2704                 if (!s->mpeg_enc_ctx_allocated)
2705                     break;
2706
2707                 if (s2->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
2708                     if (mb_y < avctx->skip_top ||
2709                         mb_y >= s2->mb_height - avctx->skip_bottom)
2710                         break;
2711                 }
2712
2713                 if (!s2->pict_type) {
2714                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2715                     if (avctx->err_recognition & AV_EF_EXPLODE)
2716                         return AVERROR_INVALIDDATA;
2717                     break;
2718                 }
2719
2720                 if (s->first_slice) {
2721                     skip_frame     = 0;
2722                     s->first_slice = 0;
2723                     if ((ret = mpeg_field_start(s2, buf, buf_size)) < 0)
2724                         return ret;
2725                 }
2726                 if (!s2->current_picture_ptr) {
2727                     av_log(avctx, AV_LOG_ERROR,
2728                            "current_picture not initialized\n");
2729                     return AVERROR_INVALIDDATA;
2730                 }
2731
2732                 if (HAVE_THREADS &&
2733                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2734                     !avctx->hwaccel) {
2735                     int threshold = (s2->mb_height * s->slice_count +
2736                                      s2->slice_context_count / 2) /
2737                                     s2->slice_context_count;
2738                     av_assert0(avctx->thread_count > 1);
2739                     if (threshold <= mb_y) {
2740                         MpegEncContext *thread_context = s2->thread_context[s->slice_count];
2741
2742                         thread_context->start_mb_y = mb_y;
2743                         thread_context->end_mb_y   = s2->mb_height;
2744                         if (s->slice_count) {
2745                             s2->thread_context[s->slice_count - 1]->end_mb_y = mb_y;
2746                             ret = ff_update_duplicate_context(thread_context, s2);
2747                             if (ret < 0)
2748                                 return ret;
2749                         }
2750                         init_get_bits(&thread_context->gb, buf_ptr, input_size * 8);
2751                         s->slice_count++;
2752                     }
2753                     buf_ptr += 2; // FIXME add minimum number of bytes per slice
2754                 } else {
2755                     ret = mpeg_decode_slice(s2, mb_y, &buf_ptr, input_size);
2756                     emms_c();
2757
2758                     if (ret < 0) {
2759                         if (avctx->err_recognition & AV_EF_EXPLODE)
2760                             return ret;
2761                         if (s2->resync_mb_x >= 0 && s2->resync_mb_y >= 0)
2762                             ff_er_add_slice(&s2->er, s2->resync_mb_x,
2763                                             s2->resync_mb_y, s2->mb_x, s2->mb_y,
2764                                             ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2765                     } else {
2766                         ff_er_add_slice(&s2->er, s2->resync_mb_x,
2767                                         s2->resync_mb_y, s2->mb_x - 1, s2->mb_y,
2768                                         ER_AC_END | ER_DC_END | ER_MV_END);
2769                     }
2770                 }
2771             }
2772             break;
2773         }
2774     }
2775 }
2776
2777 static int mpeg_decode_frame(AVCodecContext *avctx, void *data,
2778                              int *got_output, AVPacket *avpkt)
2779 {
2780     const uint8_t *buf = avpkt->data;
2781     int ret;
2782     int buf_size = avpkt->size;
2783     Mpeg1Context *s = avctx->priv_data;
2784     AVFrame *picture = data;
2785     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2786
2787     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2788         /* special case for last picture */
2789         if (s2->low_delay == 0 && s2->next_picture_ptr) {
2790             int ret = av_frame_ref(picture, s2->next_picture_ptr->f);
2791             if (ret < 0)
2792                 return ret;
2793
2794             s2->next_picture_ptr = NULL;
2795
2796             *got_output = 1;
2797         }
2798         return buf_size;
2799     }
2800
2801     if (s2->avctx->flags & AV_CODEC_FLAG_TRUNCATED) {
2802         int next = ff_mpeg1_find_frame_end(&s2->parse_context, buf,
2803                                            buf_size, NULL);
2804
2805         if (ff_combine_frame(&s2->parse_context, next,
2806                              (const uint8_t **) &buf, &buf_size) < 0)
2807             return buf_size;
2808     }
2809
2810     s2->codec_tag = avpriv_toupper4(avctx->codec_tag);
2811     if (s->mpeg_enc_ctx_allocated == 0 && (   s2->codec_tag == AV_RL32("VCR2")
2812                                            || s2->codec_tag == AV_RL32("BW10")
2813                                           ))
2814         vcr2_init_sequence(avctx);
2815
2816     s->slice_count = 0;
2817
2818     if (avctx->extradata && !s->extradata_decoded) {
2819         ret = decode_chunks(avctx, picture, got_output,
2820                             avctx->extradata, avctx->extradata_size);
2821         if (*got_output) {
2822             av_log(avctx, AV_LOG_ERROR, "picture in extradata\n");
2823             av_frame_unref(picture);
2824             *got_output = 0;
2825         }
2826         s->extradata_decoded = 1;
2827         if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) {
2828             s2->current_picture_ptr = NULL;
2829             return ret;
2830         }
2831     }
2832
2833     ret = decode_chunks(avctx, picture, got_output, buf, buf_size);
2834     if (ret<0 || *got_output) {
2835         s2->current_picture_ptr = NULL;
2836
2837         if (s2->timecode_frame_start != -1 && *got_output) {
2838             AVFrameSideData *tcside = av_frame_new_side_data(picture,
2839                                                              AV_FRAME_DATA_GOP_TIMECODE,
2840                                                              sizeof(int64_t));
2841             if (!tcside)
2842                 return AVERROR(ENOMEM);
2843             memcpy(tcside->data, &s2->timecode_frame_start, sizeof(int64_t));
2844
2845             s2->timecode_frame_start = -1;
2846         }
2847     }
2848
2849     return ret;
2850 }
2851
2852 static void flush(AVCodecContext *avctx)
2853 {
2854     Mpeg1Context *s = avctx->priv_data;
2855
2856     s->sync       = 0;
2857
2858     ff_mpeg_flush(avctx);
2859 }
2860
2861 static av_cold int mpeg_decode_end(AVCodecContext *avctx)
2862 {
2863     Mpeg1Context *s = avctx->priv_data;
2864
2865     if (s->mpeg_enc_ctx_allocated)
2866         ff_mpv_common_end(&s->mpeg_enc_ctx);
2867     av_freep(&s->a53_caption);
2868     return 0;
2869 }
2870
2871 AVCodec ff_mpeg1video_decoder = {
2872     .name                  = "mpeg1video",
2873     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2874     .type                  = AVMEDIA_TYPE_VIDEO,
2875     .id                    = AV_CODEC_ID_MPEG1VIDEO,
2876     .priv_data_size        = sizeof(Mpeg1Context),
2877     .init                  = mpeg_decode_init,
2878     .close                 = mpeg_decode_end,
2879     .decode                = mpeg_decode_frame,
2880     .capabilities          = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2881                              AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2882                              AV_CODEC_CAP_SLICE_THREADS,
2883     .caps_internal         = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
2884     .flush                 = flush,
2885     .max_lowres            = 3,
2886     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context),
2887     .hw_configs            = (const AVCodecHWConfigInternal*[]) {
2888 #if CONFIG_MPEG1_NVDEC_HWACCEL
2889                                HWACCEL_NVDEC(mpeg1),
2890 #endif
2891 #if CONFIG_MPEG1_VDPAU_HWACCEL
2892                                HWACCEL_VDPAU(mpeg1),
2893 #endif
2894 #if CONFIG_MPEG1_VIDEOTOOLBOX_HWACCEL
2895                                HWACCEL_VIDEOTOOLBOX(mpeg1),
2896 #endif
2897 #if CONFIG_MPEG1_XVMC_HWACCEL
2898                                HWACCEL_XVMC(mpeg1),
2899 #endif
2900                                NULL
2901                            },
2902 };
2903
2904 AVCodec ff_mpeg2video_decoder = {
2905     .name           = "mpeg2video",
2906     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2907     .type           = AVMEDIA_TYPE_VIDEO,
2908     .id             = AV_CODEC_ID_MPEG2VIDEO,
2909     .priv_data_size = sizeof(Mpeg1Context),
2910     .init           = mpeg_decode_init,
2911     .close          = mpeg_decode_end,
2912     .decode         = mpeg_decode_frame,
2913     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2914                       AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2915                       AV_CODEC_CAP_SLICE_THREADS,
2916     .caps_internal  = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
2917     .flush          = flush,
2918     .max_lowres     = 3,
2919     .profiles       = NULL_IF_CONFIG_SMALL(ff_mpeg2_video_profiles),
2920     .hw_configs     = (const AVCodecHWConfigInternal*[]) {
2921 #if CONFIG_MPEG2_DXVA2_HWACCEL
2922                         HWACCEL_DXVA2(mpeg2),
2923 #endif
2924 #if CONFIG_MPEG2_D3D11VA_HWACCEL
2925                         HWACCEL_D3D11VA(mpeg2),
2926 #endif
2927 #if CONFIG_MPEG2_D3D11VA2_HWACCEL
2928                         HWACCEL_D3D11VA2(mpeg2),
2929 #endif
2930 #if CONFIG_MPEG2_NVDEC_HWACCEL
2931                         HWACCEL_NVDEC(mpeg2),
2932 #endif
2933 #if CONFIG_MPEG2_VAAPI_HWACCEL
2934                         HWACCEL_VAAPI(mpeg2),
2935 #endif
2936 #if CONFIG_MPEG2_VDPAU_HWACCEL
2937                         HWACCEL_VDPAU(mpeg2),
2938 #endif
2939 #if CONFIG_MPEG2_VIDEOTOOLBOX_HWACCEL
2940                         HWACCEL_VIDEOTOOLBOX(mpeg2),
2941 #endif
2942 #if CONFIG_MPEG2_XVMC_HWACCEL
2943                         HWACCEL_XVMC(mpeg2),
2944 #endif
2945                         NULL
2946                     },
2947 };
2948
2949 //legacy decoder
2950 AVCodec ff_mpegvideo_decoder = {
2951     .name           = "mpegvideo",
2952     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2953     .type           = AVMEDIA_TYPE_VIDEO,
2954     .id             = AV_CODEC_ID_MPEG2VIDEO,
2955     .priv_data_size = sizeof(Mpeg1Context),
2956     .init           = mpeg_decode_init,
2957     .close          = mpeg_decode_end,
2958     .decode         = mpeg_decode_frame,
2959     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS,
2960     .caps_internal  = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
2961     .flush          = flush,
2962     .max_lowres     = 3,
2963 };