f5f2c696c05c59aba9e7528831ca5b1c14f39263
[ffmpeg.git] / libavcodec / mpeg12dec.c
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 static inline int get_qscale(MpegEncContext *s)
653 {
654     int qscale = get_bits(&s->gb, 5);
655     if (s->q_scale_type)
656         return ff_mpeg2_non_linear_qscale[qscale];
657     else
658         return qscale << 1;
659 }
660
661
662 /* motion type (for MPEG-2) */
663 #define MT_FIELD 1
664 #define MT_FRAME 2
665 #define MT_16X8  2
666 #define MT_DMV   3
667
668 static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
669 {
670     int i, j, k, cbp, val, mb_type, motion_type;
671     const int mb_block_count = 4 + (1 << s->chroma_format);
672     int ret;
673
674     ff_tlog(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
675
676     av_assert2(s->mb_skipped == 0);
677
678     if (s->mb_skip_run-- != 0) {
679         if (s->pict_type == AV_PICTURE_TYPE_P) {
680             s->mb_skipped = 1;
681             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
682                 MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
683         } else {
684             int mb_type;
685
686             if (s->mb_x)
687                 mb_type = s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride - 1];
688             else
689                 // FIXME not sure if this is allowed in MPEG at all
690                 mb_type = s->current_picture.mb_type[s->mb_width + (s->mb_y - 1) * s->mb_stride - 1];
691             if (IS_INTRA(mb_type)) {
692                 av_log(s->avctx, AV_LOG_ERROR, "skip with previntra\n");
693                 return AVERROR_INVALIDDATA;
694             }
695             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
696                 mb_type | MB_TYPE_SKIP;
697
698             if ((s->mv[0][0][0] | s->mv[0][0][1] | s->mv[1][0][0] | s->mv[1][0][1]) == 0)
699                 s->mb_skipped = 1;
700         }
701
702         return 0;
703     }
704
705     switch (s->pict_type) {
706     default:
707     case AV_PICTURE_TYPE_I:
708         if (get_bits1(&s->gb) == 0) {
709             if (get_bits1(&s->gb) == 0) {
710                 av_log(s->avctx, AV_LOG_ERROR,
711                        "Invalid mb type in I-frame at %d %d\n",
712                        s->mb_x, s->mb_y);
713                 return AVERROR_INVALIDDATA;
714             }
715             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
716         } else {
717             mb_type = MB_TYPE_INTRA;
718         }
719         break;
720     case AV_PICTURE_TYPE_P:
721         mb_type = get_vlc2(&s->gb, ff_mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
722         if (mb_type < 0) {
723             av_log(s->avctx, AV_LOG_ERROR,
724                    "Invalid mb type in P-frame at %d %d\n", s->mb_x, s->mb_y);
725             return AVERROR_INVALIDDATA;
726         }
727         mb_type = ptype2mb_type[mb_type];
728         break;
729     case AV_PICTURE_TYPE_B:
730         mb_type = get_vlc2(&s->gb, ff_mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
731         if (mb_type < 0) {
732             av_log(s->avctx, AV_LOG_ERROR,
733                    "Invalid mb type in B-frame at %d %d\n", s->mb_x, s->mb_y);
734             return AVERROR_INVALIDDATA;
735         }
736         mb_type = btype2mb_type[mb_type];
737         break;
738     }
739     ff_tlog(s->avctx, "mb_type=%x\n", mb_type);
740 //    motion_type = 0; /* avoid warning */
741     if (IS_INTRA(mb_type)) {
742         s->bdsp.clear_blocks(s->block[0]);
743
744         if (!s->chroma_y_shift)
745             s->bdsp.clear_blocks(s->block[6]);
746
747         /* compute DCT type */
748         // FIXME: add an interlaced_dct coded var?
749         if (s->picture_structure == PICT_FRAME &&
750             !s->frame_pred_frame_dct)
751             s->interlaced_dct = get_bits1(&s->gb);
752
753         if (IS_QUANT(mb_type))
754             s->qscale = get_qscale(s);
755
756         if (s->concealment_motion_vectors) {
757             /* just parse them */
758             if (s->picture_structure != PICT_FRAME)
759                 skip_bits1(&s->gb);  /* field select */
760
761             s->mv[0][0][0]      =
762             s->last_mv[0][0][0] =
763             s->last_mv[0][1][0] = mpeg_decode_motion(s, s->mpeg_f_code[0][0],
764                                                      s->last_mv[0][0][0]);
765             s->mv[0][0][1]      =
766             s->last_mv[0][0][1] =
767             s->last_mv[0][1][1] = mpeg_decode_motion(s, s->mpeg_f_code[0][1],
768                                                      s->last_mv[0][0][1]);
769
770             check_marker(s->avctx, &s->gb, "after concealment_motion_vectors");
771         } else {
772             /* reset mv prediction */
773             memset(s->last_mv, 0, sizeof(s->last_mv));
774         }
775         s->mb_intra = 1;
776         // if 1, we memcpy blocks in xvmcvideo
777         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
778             ff_xvmc_pack_pblocks(s, -1); // inter are always full blocks
779
780         if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
781             if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
782                 for (i = 0; i < 6; i++)
783                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
784             } else {
785                 for (i = 0; i < mb_block_count; i++)
786                     if ((ret = mpeg2_decode_block_intra(s, *s->pblocks[i], i)) < 0)
787                         return ret;
788             }
789         } else {
790             for (i = 0; i < 6; i++) {
791                 ret = ff_mpeg1_decode_block_intra(&s->gb,
792                                                   s->intra_matrix,
793                                                   s->intra_scantable.permutated,
794                                                   s->last_dc, *s->pblocks[i],
795                                                   i, s->qscale);
796                 if (ret < 0) {
797                     av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n",
798                            s->mb_x, s->mb_y);
799                     return ret;
800                 }
801
802                 s->block_last_index[i] = ret;
803             }
804         }
805     } else {
806         if (mb_type & MB_TYPE_ZERO_MV) {
807             av_assert2(mb_type & MB_TYPE_CBP);
808
809             s->mv_dir = MV_DIR_FORWARD;
810             if (s->picture_structure == PICT_FRAME) {
811                 if (s->picture_structure == PICT_FRAME
812                     && !s->frame_pred_frame_dct)
813                     s->interlaced_dct = get_bits1(&s->gb);
814                 s->mv_type = MV_TYPE_16X16;
815             } else {
816                 s->mv_type            = MV_TYPE_FIELD;
817                 mb_type              |= MB_TYPE_INTERLACED;
818                 s->field_select[0][0] = s->picture_structure - 1;
819             }
820
821             if (IS_QUANT(mb_type))
822                 s->qscale = get_qscale(s);
823
824             s->last_mv[0][0][0] = 0;
825             s->last_mv[0][0][1] = 0;
826             s->last_mv[0][1][0] = 0;
827             s->last_mv[0][1][1] = 0;
828             s->mv[0][0][0]      = 0;
829             s->mv[0][0][1]      = 0;
830         } else {
831             av_assert2(mb_type & MB_TYPE_L0L1);
832             // FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
833             /* get additional motion vector type */
834             if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) {
835                 motion_type = MT_FRAME;
836             } else {
837                 motion_type = get_bits(&s->gb, 2);
838                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
839                     s->interlaced_dct = get_bits1(&s->gb);
840             }
841
842             if (IS_QUANT(mb_type))
843                 s->qscale = get_qscale(s);
844
845             /* motion vectors */
846             s->mv_dir = (mb_type >> 13) & 3;
847             ff_tlog(s->avctx, "motion_type=%d\n", motion_type);
848             switch (motion_type) {
849             case MT_FRAME: /* or MT_16X8 */
850                 if (s->picture_structure == PICT_FRAME) {
851                     mb_type   |= MB_TYPE_16x16;
852                     s->mv_type = MV_TYPE_16X16;
853                     for (i = 0; i < 2; i++) {
854                         if (USES_LIST(mb_type, i)) {
855                             /* MT_FRAME */
856                             s->mv[i][0][0]      =
857                             s->last_mv[i][0][0] =
858                             s->last_mv[i][1][0] =
859                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0],
860                                                    s->last_mv[i][0][0]);
861                             s->mv[i][0][1]      =
862                             s->last_mv[i][0][1] =
863                             s->last_mv[i][1][1] =
864                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1],
865                                                    s->last_mv[i][0][1]);
866                             /* full_pel: only for MPEG-1 */
867                             if (s->full_pel[i]) {
868                                 s->mv[i][0][0] *= 2;
869                                 s->mv[i][0][1] *= 2;
870                             }
871                         }
872                     }
873                 } else {
874                     mb_type   |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
875                     s->mv_type = MV_TYPE_16X8;
876                     for (i = 0; i < 2; i++) {
877                         if (USES_LIST(mb_type, i)) {
878                             /* MT_16X8 */
879                             for (j = 0; j < 2; j++) {
880                                 s->field_select[i][j] = get_bits1(&s->gb);
881                                 for (k = 0; k < 2; k++) {
882                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
883                                                              s->last_mv[i][j][k]);
884                                     s->last_mv[i][j][k] = val;
885                                     s->mv[i][j][k]      = val;
886                                 }
887                             }
888                         }
889                     }
890                 }
891                 break;
892             case MT_FIELD:
893                 s->mv_type = MV_TYPE_FIELD;
894                 if (s->picture_structure == PICT_FRAME) {
895                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
896                     for (i = 0; i < 2; i++) {
897                         if (USES_LIST(mb_type, i)) {
898                             for (j = 0; j < 2; j++) {
899                                 s->field_select[i][j] = get_bits1(&s->gb);
900                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
901                                                          s->last_mv[i][j][0]);
902                                 s->last_mv[i][j][0] = val;
903                                 s->mv[i][j][0]      = val;
904                                 ff_tlog(s->avctx, "fmx=%d\n", val);
905                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
906                                                          s->last_mv[i][j][1] >> 1);
907                                 s->last_mv[i][j][1] = 2 * val;
908                                 s->mv[i][j][1]      = val;
909                                 ff_tlog(s->avctx, "fmy=%d\n", val);
910                             }
911                         }
912                     }
913                 } else {
914                     av_assert0(!s->progressive_sequence);
915                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
916                     for (i = 0; i < 2; i++) {
917                         if (USES_LIST(mb_type, i)) {
918                             s->field_select[i][0] = get_bits1(&s->gb);
919                             for (k = 0; k < 2; k++) {
920                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
921                                                          s->last_mv[i][0][k]);
922                                 s->last_mv[i][0][k] = val;
923                                 s->last_mv[i][1][k] = val;
924                                 s->mv[i][0][k]      = val;
925                             }
926                         }
927                     }
928                 }
929                 break;
930             case MT_DMV:
931                 if (s->progressive_sequence){
932                     av_log(s->avctx, AV_LOG_ERROR, "MT_DMV in progressive_sequence\n");
933                     return AVERROR_INVALIDDATA;
934                 }
935                 s->mv_type = MV_TYPE_DMV;
936                 for (i = 0; i < 2; i++) {
937                     if (USES_LIST(mb_type, i)) {
938                         int dmx, dmy, mx, my, m;
939                         const int my_shift = s->picture_structure == PICT_FRAME;
940
941                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
942                                                 s->last_mv[i][0][0]);
943                         s->last_mv[i][0][0] = mx;
944                         s->last_mv[i][1][0] = mx;
945                         dmx = get_dmv(s);
946                         my  = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
947                                                  s->last_mv[i][0][1] >> my_shift);
948                         dmy = get_dmv(s);
949
950
951                         s->last_mv[i][0][1] = my * (1 << my_shift);
952                         s->last_mv[i][1][1] = my * (1 << my_shift);
953
954                         s->mv[i][0][0] = mx;
955                         s->mv[i][0][1] = my;
956                         s->mv[i][1][0] = mx; // not used
957                         s->mv[i][1][1] = my; // not used
958
959                         if (s->picture_structure == PICT_FRAME) {
960                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
961
962                             // m = 1 + 2 * s->top_field_first;
963                             m = s->top_field_first ? 1 : 3;
964
965                             /* top -> top pred */
966                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
967                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
968                             m = 4 - m;
969                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
970                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
971                         } else {
972                             mb_type |= MB_TYPE_16x16;
973
974                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
975                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
976                             if (s->picture_structure == PICT_TOP_FIELD)
977                                 s->mv[i][2][1]--;
978                             else
979                                 s->mv[i][2][1]++;
980                         }
981                     }
982                 }
983                 break;
984             default:
985                 av_log(s->avctx, AV_LOG_ERROR,
986                        "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
987                 return AVERROR_INVALIDDATA;
988             }
989         }
990
991         s->mb_intra = 0;
992         if (HAS_CBP(mb_type)) {
993             s->bdsp.clear_blocks(s->block[0]);
994
995             cbp = get_vlc2(&s->gb, ff_mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
996             if (mb_block_count > 6) {
997                 cbp *= 1 << mb_block_count - 6;
998                 cbp  |= get_bits(&s->gb, mb_block_count - 6);
999                 s->bdsp.clear_blocks(s->block[6]);
1000             }
1001             if (cbp <= 0) {
1002                 av_log(s->avctx, AV_LOG_ERROR,
1003                        "invalid cbp %d at %d %d\n", cbp, s->mb_x, s->mb_y);
1004                 return AVERROR_INVALIDDATA;
1005             }
1006
1007             // if 1, we memcpy blocks in xvmcvideo
1008             if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1009                 ff_xvmc_pack_pblocks(s, cbp);
1010
1011             if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
1012                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1013                     for (i = 0; i < 6; i++) {
1014                         if (cbp & 32)
1015                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
1016                         else
1017                             s->block_last_index[i] = -1;
1018                         cbp += cbp;
1019                     }
1020                 } else {
1021                     cbp <<= 12 - mb_block_count;
1022
1023                     for (i = 0; i < mb_block_count; i++) {
1024                         if (cbp & (1 << 11)) {
1025                             if ((ret = mpeg2_decode_block_non_intra(s, *s->pblocks[i], i)) < 0)
1026                                 return ret;
1027                         } else {
1028                             s->block_last_index[i] = -1;
1029                         }
1030                         cbp += cbp;
1031                     }
1032                 }
1033             } else {
1034                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1035                     for (i = 0; i < 6; i++) {
1036                         if (cbp & 32)
1037                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
1038                         else
1039                             s->block_last_index[i] = -1;
1040                         cbp += cbp;
1041                     }
1042                 } else {
1043                     for (i = 0; i < 6; i++) {
1044                         if (cbp & 32) {
1045                             if ((ret = mpeg1_decode_block_inter(s, *s->pblocks[i], i)) < 0)
1046                                 return ret;
1047                         } else {
1048                             s->block_last_index[i] = -1;
1049                         }
1050                         cbp += cbp;
1051                     }
1052                 }
1053             }
1054         } else {
1055             for (i = 0; i < 12; i++)
1056                 s->block_last_index[i] = -1;
1057         }
1058     }
1059
1060     s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] = mb_type;
1061
1062     return 0;
1063 }
1064
1065 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1066 {
1067     Mpeg1Context *s    = avctx->priv_data;
1068     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1069
1070     ff_mpv_decode_defaults(s2);
1071
1072     if (   avctx->codec_tag != AV_RL32("VCR2")
1073         && avctx->codec_tag != AV_RL32("BW10"))
1074         avctx->coded_width = avctx->coded_height = 0; // do not trust dimensions from input
1075     ff_mpv_decode_init(s2, avctx);
1076
1077     s->mpeg_enc_ctx.avctx  = avctx;
1078
1079     /* we need some permutation to store matrices,
1080      * until the decoder sets the real permutation. */
1081     ff_mpv_idct_init(s2);
1082     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1083     ff_mpeg12_init_vlcs();
1084
1085     s2->chroma_format              = 1;
1086     s->mpeg_enc_ctx_allocated      = 0;
1087     s->mpeg_enc_ctx.picture_number = 0;
1088     s->repeat_field                = 0;
1089     s->mpeg_enc_ctx.codec_id       = avctx->codec->id;
1090     avctx->color_range             = AVCOL_RANGE_MPEG;
1091     return 0;
1092 }
1093
1094 #if HAVE_THREADS
1095 static int mpeg_decode_update_thread_context(AVCodecContext *avctx,
1096                                              const AVCodecContext *avctx_from)
1097 {
1098     Mpeg1Context *ctx = avctx->priv_data, *ctx_from = avctx_from->priv_data;
1099     MpegEncContext *s = &ctx->mpeg_enc_ctx, *s1 = &ctx_from->mpeg_enc_ctx;
1100     int err;
1101
1102     if (avctx == avctx_from               ||
1103         !ctx_from->mpeg_enc_ctx_allocated ||
1104         !s1->context_initialized)
1105         return 0;
1106
1107     err = ff_mpeg_update_thread_context(avctx, avctx_from);
1108     if (err)
1109         return err;
1110
1111     if (!ctx->mpeg_enc_ctx_allocated)
1112         memcpy(s + 1, s1 + 1, sizeof(Mpeg1Context) - sizeof(MpegEncContext));
1113
1114     if (!(s->pict_type == AV_PICTURE_TYPE_B || s->low_delay))
1115         s->picture_number++;
1116
1117     return 0;
1118 }
1119 #endif
1120
1121 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1122                                  const uint8_t *new_perm)
1123 {
1124     uint16_t temp_matrix[64];
1125     int i;
1126
1127     memcpy(temp_matrix, matrix, 64 * sizeof(uint16_t));
1128
1129     for (i = 0; i < 64; i++)
1130         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1131 }
1132
1133 static const enum AVPixelFormat mpeg1_hwaccel_pixfmt_list_420[] = {
1134 #if CONFIG_MPEG1_NVDEC_HWACCEL
1135     AV_PIX_FMT_CUDA,
1136 #endif
1137 #if CONFIG_MPEG1_XVMC_HWACCEL
1138     AV_PIX_FMT_XVMC,
1139 #endif
1140 #if CONFIG_MPEG1_VDPAU_HWACCEL
1141     AV_PIX_FMT_VDPAU,
1142 #endif
1143     AV_PIX_FMT_YUV420P,
1144     AV_PIX_FMT_NONE
1145 };
1146
1147 static const enum AVPixelFormat mpeg2_hwaccel_pixfmt_list_420[] = {
1148 #if CONFIG_MPEG2_NVDEC_HWACCEL
1149     AV_PIX_FMT_CUDA,
1150 #endif
1151 #if CONFIG_MPEG2_XVMC_HWACCEL
1152     AV_PIX_FMT_XVMC,
1153 #endif
1154 #if CONFIG_MPEG2_VDPAU_HWACCEL
1155     AV_PIX_FMT_VDPAU,
1156 #endif
1157 #if CONFIG_MPEG2_DXVA2_HWACCEL
1158     AV_PIX_FMT_DXVA2_VLD,
1159 #endif
1160 #if CONFIG_MPEG2_D3D11VA_HWACCEL
1161     AV_PIX_FMT_D3D11VA_VLD,
1162     AV_PIX_FMT_D3D11,
1163 #endif
1164 #if CONFIG_MPEG2_VAAPI_HWACCEL
1165     AV_PIX_FMT_VAAPI,
1166 #endif
1167 #if CONFIG_MPEG2_VIDEOTOOLBOX_HWACCEL
1168     AV_PIX_FMT_VIDEOTOOLBOX,
1169 #endif
1170     AV_PIX_FMT_YUV420P,
1171     AV_PIX_FMT_NONE
1172 };
1173
1174 static const enum AVPixelFormat mpeg12_pixfmt_list_422[] = {
1175     AV_PIX_FMT_YUV422P,
1176     AV_PIX_FMT_NONE
1177 };
1178
1179 static const enum AVPixelFormat mpeg12_pixfmt_list_444[] = {
1180     AV_PIX_FMT_YUV444P,
1181     AV_PIX_FMT_NONE
1182 };
1183
1184 static enum AVPixelFormat mpeg_get_pixelformat(AVCodecContext *avctx)
1185 {
1186     Mpeg1Context *s1  = avctx->priv_data;
1187     MpegEncContext *s = &s1->mpeg_enc_ctx;
1188     const enum AVPixelFormat *pix_fmts;
1189
1190     if (CONFIG_GRAY && (avctx->flags & AV_CODEC_FLAG_GRAY))
1191         return AV_PIX_FMT_GRAY8;
1192
1193     if (s->chroma_format < 2)
1194         pix_fmts = avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO ?
1195                                 mpeg1_hwaccel_pixfmt_list_420 :
1196                                 mpeg2_hwaccel_pixfmt_list_420;
1197     else if (s->chroma_format == 2)
1198         pix_fmts = mpeg12_pixfmt_list_422;
1199     else
1200         pix_fmts = mpeg12_pixfmt_list_444;
1201
1202     return ff_thread_get_format(avctx, pix_fmts);
1203 }
1204
1205 static void setup_hwaccel_for_pixfmt(AVCodecContext *avctx)
1206 {
1207     // until then pix_fmt may be changed right after codec init
1208     if (avctx->hwaccel)
1209         if (avctx->idct_algo == FF_IDCT_AUTO)
1210             avctx->idct_algo = FF_IDCT_NONE;
1211
1212     if (avctx->hwaccel && avctx->pix_fmt == AV_PIX_FMT_XVMC) {
1213         Mpeg1Context *s1 = avctx->priv_data;
1214         MpegEncContext *s = &s1->mpeg_enc_ctx;
1215
1216         s->pack_pblocks = 1;
1217     }
1218 }
1219
1220 /* Call this function when we know all parameters.
1221  * It may be called in different places for MPEG-1 and MPEG-2. */
1222 static int mpeg_decode_postinit(AVCodecContext *avctx)
1223 {
1224     Mpeg1Context *s1  = avctx->priv_data;
1225     MpegEncContext *s = &s1->mpeg_enc_ctx;
1226     uint8_t old_permutation[64];
1227     int ret;
1228
1229     if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1230         // MPEG-1 aspect
1231         AVRational aspect_inv = av_d2q(ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1232         avctx->sample_aspect_ratio = (AVRational) { aspect_inv.den, aspect_inv.num };
1233     } else { // MPEG-2
1234         // MPEG-2 aspect
1235         if (s->aspect_ratio_info > 1) {
1236             AVRational dar =
1237                 av_mul_q(av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1238                                   (AVRational) { s1->pan_scan.width,
1239                                                  s1->pan_scan.height }),
1240                          (AVRational) { s->width, s->height });
1241
1242             /* We ignore the spec here and guess a bit as reality does not
1243              * match the spec, see for example res_change_ffmpeg_aspect.ts
1244              * and sequence-display-aspect.mpg.
1245              * issue1613, 621, 562 */
1246             if ((s1->pan_scan.width == 0) || (s1->pan_scan.height == 0) ||
1247                 (av_cmp_q(dar, (AVRational) { 4, 3 }) &&
1248                  av_cmp_q(dar, (AVRational) { 16, 9 }))) {
1249                 s->avctx->sample_aspect_ratio =
1250                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1251                              (AVRational) { s->width, s->height });
1252             } else {
1253                 s->avctx->sample_aspect_ratio =
1254                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1255                              (AVRational) { s1->pan_scan.width, s1->pan_scan.height });
1256 // issue1613 4/3 16/9 -> 16/9
1257 // res_change_ffmpeg_aspect.ts 4/3 225/44 ->4/3
1258 // widescreen-issue562.mpg 4/3 16/9 -> 16/9
1259 //                s->avctx->sample_aspect_ratio = av_mul_q(s->avctx->sample_aspect_ratio, (AVRational) {s->width, s->height});
1260                 ff_dlog(avctx, "aspect A %d/%d\n",
1261                         ff_mpeg2_aspect[s->aspect_ratio_info].num,
1262                         ff_mpeg2_aspect[s->aspect_ratio_info].den);
1263                 ff_dlog(avctx, "aspect B %d/%d\n", s->avctx->sample_aspect_ratio.num,
1264                         s->avctx->sample_aspect_ratio.den);
1265             }
1266         } else {
1267             s->avctx->sample_aspect_ratio =
1268                 ff_mpeg2_aspect[s->aspect_ratio_info];
1269         }
1270     } // MPEG-2
1271
1272     if (av_image_check_sar(s->width, s->height,
1273                            avctx->sample_aspect_ratio) < 0) {
1274         av_log(avctx, AV_LOG_WARNING, "ignoring invalid SAR: %u/%u\n",
1275                 avctx->sample_aspect_ratio.num,
1276                 avctx->sample_aspect_ratio.den);
1277         avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
1278     }
1279
1280     if ((s1->mpeg_enc_ctx_allocated == 0)                   ||
1281         avctx->coded_width       != s->width                ||
1282         avctx->coded_height      != s->height               ||
1283         s1->save_width           != s->width                ||
1284         s1->save_height          != s->height               ||
1285         av_cmp_q(s1->save_aspect, s->avctx->sample_aspect_ratio) ||
1286         (s1->save_progressive_seq != s->progressive_sequence && FFALIGN(s->height, 16) != FFALIGN(s->height, 32)) ||
1287         0) {
1288         if (s1->mpeg_enc_ctx_allocated) {
1289             ParseContext pc = s->parse_context;
1290             s->parse_context.buffer = 0;
1291             ff_mpv_common_end(s);
1292             s->parse_context = pc;
1293             s1->mpeg_enc_ctx_allocated = 0;
1294         }
1295
1296         ret = ff_set_dimensions(avctx, s->width, s->height);
1297         if (ret < 0)
1298             return ret;
1299
1300         if (avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO && s->bit_rate) {
1301             avctx->rc_max_rate = s->bit_rate;
1302         } else if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO && s->bit_rate &&
1303                    (s->bit_rate != 0x3FFFF*400 || s->vbv_delay != 0xFFFF)) {
1304             avctx->bit_rate = s->bit_rate;
1305         }
1306         s1->save_aspect          = s->avctx->sample_aspect_ratio;
1307         s1->save_width           = s->width;
1308         s1->save_height          = s->height;
1309         s1->save_progressive_seq = s->progressive_sequence;
1310
1311         /* low_delay may be forced, in this case we will have B-frames
1312          * that behave like P-frames. */
1313         avctx->has_b_frames = !s->low_delay;
1314
1315         if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1316             // MPEG-1 fps
1317             avctx->framerate = ff_mpeg12_frame_rate_tab[s->frame_rate_index];
1318             avctx->ticks_per_frame     = 1;
1319
1320             avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1321         } else { // MPEG-2
1322             // MPEG-2 fps
1323             av_reduce(&s->avctx->framerate.num,
1324                       &s->avctx->framerate.den,
1325                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1326                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1327                       1 << 30);
1328             avctx->ticks_per_frame = 2;
1329
1330             switch (s->chroma_format) {
1331             case 1: avctx->chroma_sample_location = AVCHROMA_LOC_LEFT; break;
1332             case 2:
1333             case 3: avctx->chroma_sample_location = AVCHROMA_LOC_TOPLEFT; break;
1334             default: av_assert0(0);
1335             }
1336         } // MPEG-2
1337
1338         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1339         setup_hwaccel_for_pixfmt(avctx);
1340
1341         /* Quantization matrices may need reordering
1342          * if DCT permutation is changed. */
1343         memcpy(old_permutation, s->idsp.idct_permutation, 64 * sizeof(uint8_t));
1344
1345         ff_mpv_idct_init(s);
1346         if ((ret = ff_mpv_common_init(s)) < 0)
1347             return ret;
1348
1349         quant_matrix_rebuild(s->intra_matrix,        old_permutation, s->idsp.idct_permutation);
1350         quant_matrix_rebuild(s->inter_matrix,        old_permutation, s->idsp.idct_permutation);
1351         quant_matrix_rebuild(s->chroma_intra_matrix, old_permutation, s->idsp.idct_permutation);
1352         quant_matrix_rebuild(s->chroma_inter_matrix, old_permutation, s->idsp.idct_permutation);
1353
1354         s1->mpeg_enc_ctx_allocated = 1;
1355     }
1356     return 0;
1357 }
1358
1359 static int mpeg1_decode_picture(AVCodecContext *avctx, const uint8_t *buf,
1360                                 int buf_size)
1361 {
1362     Mpeg1Context *s1  = avctx->priv_data;
1363     MpegEncContext *s = &s1->mpeg_enc_ctx;
1364     int ref, f_code, vbv_delay;
1365
1366     init_get_bits(&s->gb, buf, buf_size * 8);
1367
1368     ref = get_bits(&s->gb, 10); /* temporal ref */
1369     s->pict_type = get_bits(&s->gb, 3);
1370     if (s->pict_type == 0 || s->pict_type > 3)
1371         return AVERROR_INVALIDDATA;
1372
1373     vbv_delay = get_bits(&s->gb, 16);
1374     s->vbv_delay = vbv_delay;
1375     if (s->pict_type == AV_PICTURE_TYPE_P ||
1376         s->pict_type == AV_PICTURE_TYPE_B) {
1377         s->full_pel[0] = get_bits1(&s->gb);
1378         f_code = get_bits(&s->gb, 3);
1379         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1380             return AVERROR_INVALIDDATA;
1381         f_code += !f_code;
1382         s->mpeg_f_code[0][0] = f_code;
1383         s->mpeg_f_code[0][1] = f_code;
1384     }
1385     if (s->pict_type == AV_PICTURE_TYPE_B) {
1386         s->full_pel[1] = get_bits1(&s->gb);
1387         f_code = get_bits(&s->gb, 3);
1388         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1389             return AVERROR_INVALIDDATA;
1390         f_code += !f_code;
1391         s->mpeg_f_code[1][0] = f_code;
1392         s->mpeg_f_code[1][1] = f_code;
1393     }
1394     s->current_picture.f->pict_type = s->pict_type;
1395     s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1396
1397     if (avctx->debug & FF_DEBUG_PICT_INFO)
1398         av_log(avctx, AV_LOG_DEBUG,
1399                "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1400
1401     s->y_dc_scale = 8;
1402     s->c_dc_scale = 8;
1403     return 0;
1404 }
1405
1406 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1407 {
1408     MpegEncContext *s = &s1->mpeg_enc_ctx;
1409     int horiz_size_ext, vert_size_ext;
1410     int bit_rate_ext;
1411
1412     skip_bits(&s->gb, 1); /* profile and level esc*/
1413     s->avctx->profile       = get_bits(&s->gb, 3);
1414     s->avctx->level         = get_bits(&s->gb, 4);
1415     s->progressive_sequence = get_bits1(&s->gb);   /* progressive_sequence */
1416     s->chroma_format        = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1417
1418     if (!s->chroma_format) {
1419         s->chroma_format = 1;
1420         av_log(s->avctx, AV_LOG_WARNING, "Chroma format invalid\n");
1421     }
1422
1423     horiz_size_ext          = get_bits(&s->gb, 2);
1424     vert_size_ext           = get_bits(&s->gb, 2);
1425     s->width  |= (horiz_size_ext << 12);
1426     s->height |= (vert_size_ext  << 12);
1427     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1428     s->bit_rate += (bit_rate_ext << 18) * 400LL;
1429     check_marker(s->avctx, &s->gb, "after bit rate extension");
1430     s->avctx->rc_buffer_size += get_bits(&s->gb, 8) * 1024 * 16 << 10;
1431
1432     s->low_delay = get_bits1(&s->gb);
1433     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
1434         s->low_delay = 1;
1435
1436     s1->frame_rate_ext.num = get_bits(&s->gb, 2) + 1;
1437     s1->frame_rate_ext.den = get_bits(&s->gb, 5) + 1;
1438
1439     ff_dlog(s->avctx, "sequence extension\n");
1440     s->codec_id = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
1441
1442     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1443         av_log(s->avctx, AV_LOG_DEBUG,
1444                "profile: %d, level: %d ps: %d cf:%d vbv buffer: %d, bitrate:%"PRId64"\n",
1445                s->avctx->profile, s->avctx->level, s->progressive_sequence, s->chroma_format,
1446                s->avctx->rc_buffer_size, s->bit_rate);
1447 }
1448
1449 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1450 {
1451     MpegEncContext *s = &s1->mpeg_enc_ctx;
1452     int color_description, w, h;
1453
1454     skip_bits(&s->gb, 3); /* video format */
1455     color_description = get_bits1(&s->gb);
1456     if (color_description) {
1457         s->avctx->color_primaries = get_bits(&s->gb, 8);
1458         s->avctx->color_trc       = get_bits(&s->gb, 8);
1459         s->avctx->colorspace      = get_bits(&s->gb, 8);
1460     }
1461     w = get_bits(&s->gb, 14);
1462     skip_bits(&s->gb, 1); // marker
1463     h = get_bits(&s->gb, 14);
1464     // remaining 3 bits are zero padding
1465
1466     s1->pan_scan.width  = 16 * w;
1467     s1->pan_scan.height = 16 * h;
1468
1469     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1470         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1471 }
1472
1473 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1474 {
1475     MpegEncContext *s = &s1->mpeg_enc_ctx;
1476     int i, nofco;
1477
1478     nofco = 1;
1479     if (s->progressive_sequence) {
1480         if (s->repeat_first_field) {
1481             nofco++;
1482             if (s->top_field_first)
1483                 nofco++;
1484         }
1485     } else {
1486         if (s->picture_structure == PICT_FRAME) {
1487             nofco++;
1488             if (s->repeat_first_field)
1489                 nofco++;
1490         }
1491     }
1492     for (i = 0; i < nofco; i++) {
1493         s1->pan_scan.position[i][0] = get_sbits(&s->gb, 16);
1494         skip_bits(&s->gb, 1); // marker
1495         s1->pan_scan.position[i][1] = get_sbits(&s->gb, 16);
1496         skip_bits(&s->gb, 1); // marker
1497     }
1498
1499     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1500         av_log(s->avctx, AV_LOG_DEBUG,
1501                "pde (%"PRId16",%"PRId16") (%"PRId16",%"PRId16") (%"PRId16",%"PRId16")\n",
1502                s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1503                s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1504                s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]);
1505 }
1506
1507 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64],
1508                        uint16_t matrix1[64], int intra)
1509 {
1510     int i;
1511
1512     for (i = 0; i < 64; i++) {
1513         int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1514         int v = get_bits(&s->gb, 8);
1515         if (v == 0) {
1516             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1517             return AVERROR_INVALIDDATA;
1518         }
1519         if (intra && i == 0 && v != 8) {
1520             av_log(s->avctx, AV_LOG_DEBUG, "intra matrix specifies invalid DC quantizer %d, ignoring\n", v);
1521             v = 8; // needed by pink.mpg / issue1046
1522         }
1523         matrix0[j] = v;
1524         if (matrix1)
1525             matrix1[j] = v;
1526     }
1527     return 0;
1528 }
1529
1530 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1531 {
1532     ff_dlog(s->avctx, "matrix extension\n");
1533
1534     if (get_bits1(&s->gb))
1535         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1536     if (get_bits1(&s->gb))
1537         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1538     if (get_bits1(&s->gb))
1539         load_matrix(s, s->chroma_intra_matrix, NULL, 1);
1540     if (get_bits1(&s->gb))
1541         load_matrix(s, s->chroma_inter_matrix, NULL, 0);
1542 }
1543
1544 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1545 {
1546     MpegEncContext *s = &s1->mpeg_enc_ctx;
1547
1548     s->full_pel[0]       = s->full_pel[1] = 0;
1549     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1550     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1551     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1552     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1553     if (!s->pict_type && s1->mpeg_enc_ctx_allocated) {
1554         av_log(s->avctx, AV_LOG_ERROR,
1555                "Missing picture start code, guessing missing values\n");
1556         if (s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1] == 15) {
1557             if (s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1558                 s->pict_type = AV_PICTURE_TYPE_I;
1559             else
1560                 s->pict_type = AV_PICTURE_TYPE_P;
1561         } else
1562             s->pict_type = AV_PICTURE_TYPE_B;
1563         s->current_picture.f->pict_type = s->pict_type;
1564         s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1565     }
1566     s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0];
1567     s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1];
1568     s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0];
1569     s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1];
1570
1571     s->intra_dc_precision         = get_bits(&s->gb, 2);
1572     s->picture_structure          = get_bits(&s->gb, 2);
1573     s->top_field_first            = get_bits1(&s->gb);
1574     s->frame_pred_frame_dct       = get_bits1(&s->gb);
1575     s->concealment_motion_vectors = get_bits1(&s->gb);
1576     s->q_scale_type               = get_bits1(&s->gb);
1577     s->intra_vlc_format           = get_bits1(&s->gb);
1578     s->alternate_scan             = get_bits1(&s->gb);
1579     s->repeat_first_field         = get_bits1(&s->gb);
1580     s->chroma_420_type            = get_bits1(&s->gb);
1581     s->progressive_frame          = get_bits1(&s->gb);
1582
1583     if (s->alternate_scan) {
1584         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
1585         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
1586     } else {
1587         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
1588         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
1589     }
1590
1591     /* composite display not parsed */
1592     ff_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1593     ff_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
1594     ff_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
1595     ff_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1596     ff_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1597     ff_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1598     ff_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1599     ff_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1600     ff_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1601 }
1602
1603 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size)
1604 {
1605     AVCodecContext *avctx = s->avctx;
1606     Mpeg1Context *s1      = (Mpeg1Context *) s;
1607     int ret;
1608
1609     /* start frame decoding */
1610     if (s->first_field || s->picture_structure == PICT_FRAME) {
1611         AVFrameSideData *pan_scan;
1612
1613         if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
1614             return ret;
1615
1616         ff_mpeg_er_frame_start(s);
1617
1618         /* first check if we must repeat the frame */
1619         s->current_picture_ptr->f->repeat_pict = 0;
1620         if (s->repeat_first_field) {
1621             if (s->progressive_sequence) {
1622                 if (s->top_field_first)
1623                     s->current_picture_ptr->f->repeat_pict = 4;
1624                 else
1625                     s->current_picture_ptr->f->repeat_pict = 2;
1626             } else if (s->progressive_frame) {
1627                 s->current_picture_ptr->f->repeat_pict = 1;
1628             }
1629         }
1630
1631         pan_scan = av_frame_new_side_data(s->current_picture_ptr->f,
1632                                           AV_FRAME_DATA_PANSCAN,
1633                                           sizeof(s1->pan_scan));
1634         if (!pan_scan)
1635             return AVERROR(ENOMEM);
1636         memcpy(pan_scan->data, &s1->pan_scan, sizeof(s1->pan_scan));
1637
1638         if (s1->a53_caption) {
1639             AVFrameSideData *sd = av_frame_new_side_data(
1640                 s->current_picture_ptr->f, AV_FRAME_DATA_A53_CC,
1641                 s1->a53_caption_size);
1642             if (sd)
1643                 memcpy(sd->data, s1->a53_caption, s1->a53_caption_size);
1644             av_freep(&s1->a53_caption);
1645         }
1646
1647         if (s1->has_stereo3d) {
1648             AVStereo3D *stereo = av_stereo3d_create_side_data(s->current_picture_ptr->f);
1649             if (!stereo)
1650                 return AVERROR(ENOMEM);
1651
1652             *stereo = s1->stereo3d;
1653             s1->has_stereo3d = 0;
1654         }
1655
1656         if (s1->has_afd) {
1657             AVFrameSideData *sd =
1658                 av_frame_new_side_data(s->current_picture_ptr->f,
1659                                        AV_FRAME_DATA_AFD, 1);
1660             if (!sd)
1661                 return AVERROR(ENOMEM);
1662
1663             *sd->data   = s1->afd;
1664             s1->has_afd = 0;
1665         }
1666
1667         if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_FRAME))
1668             ff_thread_finish_setup(avctx);
1669     } else { // second field
1670         int i;
1671
1672         if (!s->current_picture_ptr) {
1673             av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1674             return AVERROR_INVALIDDATA;
1675         }
1676
1677         if (s->avctx->hwaccel &&
1678             (s->avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
1679             if ((ret = s->avctx->hwaccel->end_frame(s->avctx)) < 0) {
1680                 av_log(avctx, AV_LOG_ERROR,
1681                        "hardware accelerator failed to decode first field\n");
1682                 return ret;
1683             }
1684         }
1685
1686         for (i = 0; i < 4; i++) {
1687             s->current_picture.f->data[i] = s->current_picture_ptr->f->data[i];
1688             if (s->picture_structure == PICT_BOTTOM_FIELD)
1689                 s->current_picture.f->data[i] +=
1690                     s->current_picture_ptr->f->linesize[i];
1691         }
1692     }
1693
1694     if (avctx->hwaccel) {
1695         if ((ret = avctx->hwaccel->start_frame(avctx, buf, buf_size)) < 0)
1696             return ret;
1697     }
1698
1699     return 0;
1700 }
1701
1702 #define DECODE_SLICE_ERROR -1
1703 #define DECODE_SLICE_OK     0
1704
1705 /**
1706  * Decode a slice.
1707  * MpegEncContext.mb_y must be set to the MB row from the startcode.
1708  * @return DECODE_SLICE_ERROR if the slice is damaged,
1709  *         DECODE_SLICE_OK if this slice is OK
1710  */
1711 static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
1712                              const uint8_t **buf, int buf_size)
1713 {
1714     AVCodecContext *avctx = s->avctx;
1715     const int lowres      = s->avctx->lowres;
1716     const int field_pic   = s->picture_structure != PICT_FRAME;
1717     int ret;
1718
1719     s->resync_mb_x =
1720     s->resync_mb_y = -1;
1721
1722     av_assert0(mb_y < s->mb_height);
1723
1724     init_get_bits(&s->gb, *buf, buf_size * 8);
1725     if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
1726         skip_bits(&s->gb, 3);
1727
1728     ff_mpeg1_clean_buffers(s);
1729     s->interlaced_dct = 0;
1730
1731     s->qscale = get_qscale(s);
1732
1733     if (s->qscale == 0) {
1734         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1735         return AVERROR_INVALIDDATA;
1736     }
1737
1738     /* extra slice info */
1739     if (skip_1stop_8data_bits(&s->gb) < 0)
1740         return AVERROR_INVALIDDATA;
1741
1742     s->mb_x = 0;
1743
1744     if (mb_y == 0 && s->codec_tag == AV_RL32("SLIF")) {
1745         skip_bits1(&s->gb);
1746     } else {
1747         while (get_bits_left(&s->gb) > 0) {
1748             int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1749                                 MBINCR_VLC_BITS, 2);
1750             if (code < 0) {
1751                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1752                 return AVERROR_INVALIDDATA;
1753             }
1754             if (code >= 33) {
1755                 if (code == 33)
1756                     s->mb_x += 33;
1757                 /* otherwise, stuffing, nothing to do */
1758             } else {
1759                 s->mb_x += code;
1760                 break;
1761             }
1762         }
1763     }
1764
1765     if (s->mb_x >= (unsigned) s->mb_width) {
1766         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1767         return AVERROR_INVALIDDATA;
1768     }
1769
1770     if (avctx->hwaccel && avctx->hwaccel->decode_slice) {
1771         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1772         int start_code = -1;
1773         buf_end = avpriv_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1774         if (buf_end < *buf + buf_size)
1775             buf_end -= 4;
1776         s->mb_y = mb_y;
1777         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1778             return DECODE_SLICE_ERROR;
1779         *buf = buf_end;
1780         return DECODE_SLICE_OK;
1781     }
1782
1783     s->resync_mb_x = s->mb_x;
1784     s->resync_mb_y = s->mb_y = mb_y;
1785     s->mb_skip_run = 0;
1786     ff_init_block_index(s);
1787
1788     if (s->mb_y == 0 && s->mb_x == 0 && (s->first_field || s->picture_structure == PICT_FRAME)) {
1789         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
1790             av_log(s->avctx, AV_LOG_DEBUG,
1791                    "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",
1792                    s->qscale,
1793                    s->mpeg_f_code[0][0], s->mpeg_f_code[0][1],
1794                    s->mpeg_f_code[1][0], s->mpeg_f_code[1][1],
1795                    s->pict_type  == AV_PICTURE_TYPE_I ? "I" :
1796                    (s->pict_type == AV_PICTURE_TYPE_P ? "P" :
1797                    (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
1798                    s->progressive_sequence ? "ps"  : "",
1799                    s->progressive_frame    ? "pf"  : "",
1800                    s->alternate_scan       ? "alt" : "",
1801                    s->top_field_first      ? "top" : "",
1802                    s->intra_dc_precision, s->picture_structure,
1803                    s->frame_pred_frame_dct, s->concealment_motion_vectors,
1804                    s->q_scale_type, s->intra_vlc_format,
1805                    s->repeat_first_field, s->chroma_420_type ? "420" : "");
1806         }
1807     }
1808
1809     for (;;) {
1810         // If 1, we memcpy blocks in xvmcvideo.
1811         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1812             ff_xvmc_init_block(s); // set s->block
1813
1814         if ((ret = mpeg_decode_mb(s, s->block)) < 0)
1815             return ret;
1816
1817         // Note motion_val is normally NULL unless we want to extract the MVs.
1818         if (s->current_picture.motion_val[0] && !s->encoding) {
1819             const int wrap = s->b8_stride;
1820             int xy         = s->mb_x * 2 + s->mb_y * 2 * wrap;
1821             int b8_xy      = 4 * (s->mb_x + s->mb_y * s->mb_stride);
1822             int motion_x, motion_y, dir, i;
1823
1824             for (i = 0; i < 2; i++) {
1825                 for (dir = 0; dir < 2; dir++) {
1826                     if (s->mb_intra ||
1827                         (dir == 1 && s->pict_type != AV_PICTURE_TYPE_B)) {
1828                         motion_x = motion_y = 0;
1829                     } else if (s->mv_type == MV_TYPE_16X16 ||
1830                                (s->mv_type == MV_TYPE_FIELD && field_pic)) {
1831                         motion_x = s->mv[dir][0][0];
1832                         motion_y = s->mv[dir][0][1];
1833                     } else { /* if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8)) */
1834                         motion_x = s->mv[dir][i][0];
1835                         motion_y = s->mv[dir][i][1];
1836                     }
1837
1838                     s->current_picture.motion_val[dir][xy][0]     = motion_x;
1839                     s->current_picture.motion_val[dir][xy][1]     = motion_y;
1840                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1841                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1842                     s->current_picture.ref_index [dir][b8_xy]     =
1843                     s->current_picture.ref_index [dir][b8_xy + 1] = s->field_select[dir][i];
1844                     av_assert2(s->field_select[dir][i] == 0 ||
1845                                s->field_select[dir][i] == 1);
1846                 }
1847                 xy    += wrap;
1848                 b8_xy += 2;
1849             }
1850         }
1851
1852         s->dest[0] += 16 >> lowres;
1853         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1854         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1855
1856         ff_mpv_reconstruct_mb(s, s->block);
1857
1858         if (++s->mb_x >= s->mb_width) {
1859             const int mb_size = 16 >> s->avctx->lowres;
1860             int left;
1861
1862             ff_mpeg_draw_horiz_band(s, mb_size * (s->mb_y >> field_pic), mb_size);
1863             ff_mpv_report_decode_progress(s);
1864
1865             s->mb_x  = 0;
1866             s->mb_y += 1 << field_pic;
1867
1868             if (s->mb_y >= s->mb_height) {
1869                 int left   = get_bits_left(&s->gb);
1870                 int is_d10 = s->chroma_format == 2 &&
1871                              s->pict_type == AV_PICTURE_TYPE_I &&
1872                              avctx->profile == 0 && avctx->level == 5 &&
1873                              s->intra_dc_precision == 2 &&
1874                              s->q_scale_type == 1 && s->alternate_scan == 0 &&
1875                              s->progressive_frame == 0
1876                              /* vbv_delay == 0xBBB || 0xE10 */;
1877
1878                 if (left >= 32 && !is_d10) {
1879                     GetBitContext gb = s->gb;
1880                     align_get_bits(&gb);
1881                     if (show_bits(&gb, 24) == 0x060E2B) {
1882                         av_log(avctx, AV_LOG_DEBUG, "Invalid MXF data found in video stream\n");
1883                         is_d10 = 1;
1884                     }
1885                     if (left > 32 && show_bits_long(&gb, 32) == 0x201) {
1886                         av_log(avctx, AV_LOG_DEBUG, "skipping m704 alpha (unsupported)\n");
1887                         goto eos;
1888                     }
1889                 }
1890
1891                 if (left < 0 ||
1892                     (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10) ||
1893                     ((avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE)) && left > 8)) {
1894                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X at %d %d\n",
1895                            left, left>0 ? show_bits(&s->gb, FFMIN(left, 23)) : 0, s->mb_x, s->mb_y);
1896                     return AVERROR_INVALIDDATA;
1897                 } else
1898                     goto eos;
1899             }
1900             // There are some files out there which are missing the last slice
1901             // in cases where the slice is completely outside the visible
1902             // area, we detect this here instead of running into the end expecting
1903             // more data
1904             left = get_bits_left(&s->gb);
1905             if (s->mb_y >= ((s->height + 15) >> 4) &&
1906                 !s->progressive_sequence &&
1907                 left <= 25 &&
1908                 left >= 0 &&
1909                 s->mb_skip_run == -1 &&
1910                 (!left || show_bits(&s->gb, left) == 0))
1911                 goto eos;
1912
1913             ff_init_block_index(s);
1914         }
1915
1916         /* skip mb handling */
1917         if (s->mb_skip_run == -1) {
1918             /* read increment again */
1919             s->mb_skip_run = 0;
1920             for (;;) {
1921                 int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1922                                     MBINCR_VLC_BITS, 2);
1923                 if (code < 0) {
1924                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1925                     return AVERROR_INVALIDDATA;
1926                 }
1927                 if (code >= 33) {
1928                     if (code == 33) {
1929                         s->mb_skip_run += 33;
1930                     } else if (code == 35) {
1931                         if (s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0) {
1932                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1933                             return AVERROR_INVALIDDATA;
1934                         }
1935                         goto eos; /* end of slice */
1936                     }
1937                     /* otherwise, stuffing, nothing to do */
1938                 } else {
1939                     s->mb_skip_run += code;
1940                     break;
1941                 }
1942             }
1943             if (s->mb_skip_run) {
1944                 int i;
1945                 if (s->pict_type == AV_PICTURE_TYPE_I) {
1946                     av_log(s->avctx, AV_LOG_ERROR,
1947                            "skipped MB in I-frame at %d %d\n", s->mb_x, s->mb_y);
1948                     return AVERROR_INVALIDDATA;
1949                 }
1950
1951                 /* skip mb */
1952                 s->mb_intra = 0;
1953                 for (i = 0; i < 12; i++)
1954                     s->block_last_index[i] = -1;
1955                 if (s->picture_structure == PICT_FRAME)
1956                     s->mv_type = MV_TYPE_16X16;
1957                 else
1958                     s->mv_type = MV_TYPE_FIELD;
1959                 if (s->pict_type == AV_PICTURE_TYPE_P) {
1960                     /* if P type, zero motion vector is implied */
1961                     s->mv_dir             = MV_DIR_FORWARD;
1962                     s->mv[0][0][0]        = s->mv[0][0][1]      = 0;
1963                     s->last_mv[0][0][0]   = s->last_mv[0][0][1] = 0;
1964                     s->last_mv[0][1][0]   = s->last_mv[0][1][1] = 0;
1965                     s->field_select[0][0] = (s->picture_structure - 1) & 1;
1966                 } else {
1967                     /* if B type, reuse previous vectors and directions */
1968                     s->mv[0][0][0] = s->last_mv[0][0][0];
1969                     s->mv[0][0][1] = s->last_mv[0][0][1];
1970                     s->mv[1][0][0] = s->last_mv[1][0][0];
1971                     s->mv[1][0][1] = s->last_mv[1][0][1];
1972                 }
1973             }
1974         }
1975     }
1976 eos: // end of slice
1977     if (get_bits_left(&s->gb) < 0) {
1978         av_log(s, AV_LOG_ERROR, "overread %d\n", -get_bits_left(&s->gb));
1979         return AVERROR_INVALIDDATA;
1980     }
1981     *buf += (get_bits_count(&s->gb) - 1) / 8;
1982     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);
1983     return 0;
1984 }
1985
1986 static int slice_decode_thread(AVCodecContext *c, void *arg)
1987 {
1988     MpegEncContext *s   = *(void **) arg;
1989     const uint8_t *buf  = s->gb.buffer;
1990     int mb_y            = s->start_mb_y;
1991     const int field_pic = s->picture_structure != PICT_FRAME;
1992
1993     s->er.error_count = (3 * (s->end_mb_y - s->start_mb_y) * s->mb_width) >> field_pic;
1994
1995     for (;;) {
1996         uint32_t start_code;
1997         int ret;
1998
1999         ret = mpeg_decode_slice(s, mb_y, &buf, s->gb.buffer_end - buf);
2000         emms_c();
2001         ff_dlog(c, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
2002                 ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y,
2003                 s->start_mb_y, s->end_mb_y, s->er.error_count);
2004         if (ret < 0) {
2005             if (c->err_recognition & AV_EF_EXPLODE)
2006                 return ret;
2007             if (s->resync_mb_x >= 0 && s->resync_mb_y >= 0)
2008                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2009                                 s->mb_x, s->mb_y,
2010                                 ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2011         } else {
2012             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2013                             s->mb_x - 1, s->mb_y,
2014                             ER_AC_END | ER_DC_END | ER_MV_END);
2015         }
2016
2017         if (s->mb_y == s->end_mb_y)
2018             return 0;
2019
2020         start_code = -1;
2021         buf        = avpriv_find_start_code(buf, s->gb.buffer_end, &start_code);
2022         mb_y       = start_code - SLICE_MIN_START_CODE;
2023         if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
2024             mb_y += (*buf&0xE0)<<2;
2025         mb_y <<= field_pic;
2026         if (s->picture_structure == PICT_BOTTOM_FIELD)
2027             mb_y++;
2028         if (mb_y < 0 || mb_y >= s->end_mb_y)
2029             return AVERROR_INVALIDDATA;
2030     }
2031 }
2032
2033 /**
2034  * Handle slice ends.
2035  * @return 1 if it seems to be the last slice
2036  */
2037 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
2038 {
2039     Mpeg1Context *s1  = avctx->priv_data;
2040     MpegEncContext *s = &s1->mpeg_enc_ctx;
2041
2042     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
2043         return 0;
2044
2045     if (s->avctx->hwaccel) {
2046         int ret = s->avctx->hwaccel->end_frame(s->avctx);
2047         if (ret < 0) {
2048             av_log(avctx, AV_LOG_ERROR,
2049                    "hardware accelerator failed to decode picture\n");
2050             return ret;
2051         }
2052     }
2053
2054     /* end of slice reached */
2055     if (/* s->mb_y << field_pic == s->mb_height && */ !s->first_field && !s1->first_slice) {
2056         /* end of image */
2057
2058         ff_er_frame_end(&s->er);
2059
2060         ff_mpv_frame_end(s);
2061
2062         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
2063             int ret = av_frame_ref(pict, s->current_picture_ptr->f);
2064             if (ret < 0)
2065                 return ret;
2066             ff_print_debug_info(s, s->current_picture_ptr, pict);
2067             ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2068         } else {
2069             if (avctx->active_thread_type & FF_THREAD_FRAME)
2070                 s->picture_number++;
2071             /* latency of 1 frame for I- and P-frames */
2072             /* XXX: use another variable than picture_number */
2073             if (s->last_picture_ptr) {
2074                 int ret = av_frame_ref(pict, s->last_picture_ptr->f);
2075                 if (ret < 0)
2076                     return ret;
2077                 ff_print_debug_info(s, s->last_picture_ptr, pict);
2078                 ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2079             }
2080         }
2081
2082         return 1;
2083     } else {
2084         return 0;
2085     }
2086 }
2087
2088 static int mpeg1_decode_sequence(AVCodecContext *avctx,
2089                                  const uint8_t *buf, int buf_size)
2090 {
2091     Mpeg1Context *s1  = avctx->priv_data;
2092     MpegEncContext *s = &s1->mpeg_enc_ctx;
2093     int width, height;
2094     int i, v, j;
2095
2096     init_get_bits(&s->gb, buf, buf_size * 8);
2097
2098     width  = get_bits(&s->gb, 12);
2099     height = get_bits(&s->gb, 12);
2100     if (width == 0 || height == 0) {
2101         av_log(avctx, AV_LOG_WARNING,
2102                "Invalid horizontal or vertical size value.\n");
2103         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2104             return AVERROR_INVALIDDATA;
2105     }
2106     s->aspect_ratio_info = get_bits(&s->gb, 4);
2107     if (s->aspect_ratio_info == 0) {
2108         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
2109         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2110             return AVERROR_INVALIDDATA;
2111     }
2112     s->frame_rate_index = get_bits(&s->gb, 4);
2113     if (s->frame_rate_index == 0 || s->frame_rate_index > 13) {
2114         av_log(avctx, AV_LOG_WARNING,
2115                "frame_rate_index %d is invalid\n", s->frame_rate_index);
2116         s->frame_rate_index = 1;
2117     }
2118     s->bit_rate = get_bits(&s->gb, 18) * 400LL;
2119     if (check_marker(s->avctx, &s->gb, "in sequence header") == 0) {
2120         return AVERROR_INVALIDDATA;
2121     }
2122
2123     s->avctx->rc_buffer_size = get_bits(&s->gb, 10) * 1024 * 16;
2124     skip_bits(&s->gb, 1);
2125
2126     /* get matrix */
2127     if (get_bits1(&s->gb)) {
2128         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2129     } else {
2130         for (i = 0; i < 64; i++) {
2131             j = s->idsp.idct_permutation[i];
2132             v = ff_mpeg1_default_intra_matrix[i];
2133             s->intra_matrix[j]        = v;
2134             s->chroma_intra_matrix[j] = v;
2135         }
2136     }
2137     if (get_bits1(&s->gb)) {
2138         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2139     } else {
2140         for (i = 0; i < 64; i++) {
2141             int j = s->idsp.idct_permutation[i];
2142             v = ff_mpeg1_default_non_intra_matrix[i];
2143             s->inter_matrix[j]        = v;
2144             s->chroma_inter_matrix[j] = v;
2145         }
2146     }
2147
2148     if (show_bits(&s->gb, 23) != 0) {
2149         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2150         return AVERROR_INVALIDDATA;
2151     }
2152
2153     s->width  = width;
2154     s->height = height;
2155
2156     /* We set MPEG-2 parameters so that it emulates MPEG-1. */
2157     s->progressive_sequence = 1;
2158     s->progressive_frame    = 1;
2159     s->picture_structure    = PICT_FRAME;
2160     s->first_field          = 0;
2161     s->frame_pred_frame_dct = 1;
2162     s->chroma_format        = 1;
2163     s->codec_id             =
2164     s->avctx->codec_id      = AV_CODEC_ID_MPEG1VIDEO;
2165     s->out_format           = FMT_MPEG1;
2166     s->swap_uv              = 0; // AFAIK VCR2 does not have SEQ_HEADER
2167     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
2168         s->low_delay = 1;
2169
2170     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2171         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%"PRId64", aspect_ratio_info: %d \n",
2172                s->avctx->rc_buffer_size, s->bit_rate, s->aspect_ratio_info);
2173
2174     return 0;
2175 }
2176
2177 static int vcr2_init_sequence(AVCodecContext *avctx)
2178 {
2179     Mpeg1Context *s1  = avctx->priv_data;
2180     MpegEncContext *s = &s1->mpeg_enc_ctx;
2181     int i, v, ret;
2182
2183     /* start new MPEG-1 context decoding */
2184     s->out_format = FMT_MPEG1;
2185     if (s1->mpeg_enc_ctx_allocated) {
2186         ff_mpv_common_end(s);
2187         s1->mpeg_enc_ctx_allocated = 0;
2188     }
2189     s->width            = avctx->coded_width;
2190     s->height           = avctx->coded_height;
2191     avctx->has_b_frames = 0; // true?
2192     s->low_delay        = 1;
2193
2194     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2195     setup_hwaccel_for_pixfmt(avctx);
2196
2197     ff_mpv_idct_init(s);
2198     if ((ret = ff_mpv_common_init(s)) < 0)
2199         return ret;
2200     s1->mpeg_enc_ctx_allocated = 1;
2201
2202     for (i = 0; i < 64; i++) {
2203         int j = s->idsp.idct_permutation[i];
2204         v = ff_mpeg1_default_intra_matrix[i];
2205         s->intra_matrix[j]        = v;
2206         s->chroma_intra_matrix[j] = v;
2207
2208         v = ff_mpeg1_default_non_intra_matrix[i];
2209         s->inter_matrix[j]        = v;
2210         s->chroma_inter_matrix[j] = v;
2211     }
2212
2213     s->progressive_sequence  = 1;
2214     s->progressive_frame     = 1;
2215     s->picture_structure     = PICT_FRAME;
2216     s->first_field           = 0;
2217     s->frame_pred_frame_dct  = 1;
2218     s->chroma_format         = 1;
2219     if (s->codec_tag == AV_RL32("BW10")) {
2220         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
2221     } else {
2222         s->swap_uv = 1; // in case of xvmc we need to swap uv for each MB
2223         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
2224     }
2225     s1->save_width           = s->width;
2226     s1->save_height          = s->height;
2227     s1->save_progressive_seq = s->progressive_sequence;
2228     return 0;
2229 }
2230
2231 static int mpeg_decode_a53_cc(AVCodecContext *avctx,
2232                               const uint8_t *p, int buf_size)
2233 {
2234     Mpeg1Context *s1 = avctx->priv_data;
2235
2236     if (buf_size >= 6 &&
2237         p[0] == 'G' && p[1] == 'A' && p[2] == '9' && p[3] == '4' &&
2238         p[4] == 3 && (p[5] & 0x40)) {
2239         /* extract A53 Part 4 CC data */
2240         int cc_count = p[5] & 0x1f;
2241         if (cc_count > 0 && buf_size >= 7 + cc_count * 3) {
2242             av_freep(&s1->a53_caption);
2243             s1->a53_caption_size = cc_count * 3;
2244             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2245             if (!s1->a53_caption) {
2246                 s1->a53_caption_size = 0;
2247             } else {
2248                 memcpy(s1->a53_caption, p + 7, s1->a53_caption_size);
2249             }
2250             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
2251         }
2252         return 1;
2253     } else if (buf_size >= 2 &&
2254                p[0] == 0x03 && (p[1]&0x7f) == 0x01) {
2255         /* extract SCTE-20 CC data */
2256         GetBitContext gb;
2257         int cc_count = 0;
2258         int i;
2259
2260         init_get_bits(&gb, p + 2, buf_size - 2);
2261         cc_count = get_bits(&gb, 5);
2262         if (cc_count > 0) {
2263             av_freep(&s1->a53_caption);
2264             s1->a53_caption_size = cc_count * 3;
2265             s1->a53_caption      = av_mallocz(s1->a53_caption_size);
2266             if (!s1->a53_caption) {
2267                 s1->a53_caption_size = 0;
2268             } else {
2269                 uint8_t field, cc1, cc2;
2270                 uint8_t *cap = s1->a53_caption;
2271                 for (i = 0; i < cc_count && get_bits_left(&gb) >= 26; i++) {
2272                     skip_bits(&gb, 2); // priority
2273                     field = get_bits(&gb, 2);
2274                     skip_bits(&gb, 5); // line_offset
2275                     cc1 = get_bits(&gb, 8);
2276                     cc2 = get_bits(&gb, 8);
2277                     skip_bits(&gb, 1); // marker
2278
2279                     if (!field) { // forbidden
2280                         cap[0] = cap[1] = cap[2] = 0x00;
2281                     } else {
2282                         field = (field == 2 ? 1 : 0);
2283                         if (!s1->mpeg_enc_ctx.top_field_first) field = !field;
2284                         cap[0] = 0x04 | field;
2285                         cap[1] = ff_reverse[cc1];
2286                         cap[2] = ff_reverse[cc2];
2287                     }
2288                     cap += 3;
2289                 }
2290             }
2291             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
2292         }
2293         return 1;
2294     } else if (buf_size >= 11 &&
2295                p[0] == 'C' && p[1] == 'C' && p[2] == 0x01 && p[3] == 0xf8) {
2296         /* extract DVD CC data
2297          *
2298          * uint32_t   user_data_start_code        0x000001B2    (big endian)
2299          * uint16_t   user_identifier             0x4343 "CC"
2300          * uint8_t    user_data_type_code         0x01
2301          * uint8_t    caption_block_size          0xF8
2302          * uint8_t
2303          *   bit 7    caption_odd_field_first     1=odd field (CC1/CC2) first  0=even field (CC3/CC4) first
2304          *   bit 6    caption_filler              0
2305          *   bit 5:1  caption_block_count         number of caption blocks (pairs of caption words = frames). Most DVDs use 15 per start of GOP.
2306          *   bit 0    caption_extra_field_added   1=one additional caption word
2307          *
2308          * struct caption_field_block {
2309          *   uint8_t
2310          *     bit 7:1 caption_filler             0x7F (all 1s)
2311          *     bit 0   caption_field_odd          1=odd field (this is CC1/CC2)  0=even field (this is CC3/CC4)
2312          *   uint8_t   caption_first_byte
2313          *   uint8_t   caption_second_byte
2314          * } caption_block[(caption_block_count * 2) + caption_extra_field_added];
2315          *
2316          * Some DVDs encode caption data for both fields with caption_field_odd=1. The only way to decode the fields
2317          * correctly is to start on the field indicated by caption_odd_field_first and count between odd/even fields.
2318          * Don't assume that the first caption word is the odd field. There do exist MPEG files in the wild that start
2319          * on the even field. There also exist DVDs in the wild that encode an odd field count and the
2320          * caption_extra_field_added/caption_odd_field_first bits change per packet to allow that. */
2321         int cc_count = 0;
2322         int i;
2323         // There is a caption count field in the data, but it is often
2324         // incorrect.  So count the number of captions present.
2325         for (i = 5; i + 6 <= buf_size && ((p[i] & 0xfe) == 0xfe); i += 6)
2326             cc_count++;
2327         // Transform the DVD format into A53 Part 4 format
2328         if (cc_count > 0) {
2329             av_freep(&s1->a53_caption);
2330             s1->a53_caption_size = cc_count * 6;
2331             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2332             if (!s1->a53_caption) {
2333                 s1->a53_caption_size = 0;
2334             } else {
2335                 uint8_t field1 = !!(p[4] & 0x80);
2336                 uint8_t *cap = s1->a53_caption;
2337                 p += 5;
2338                 for (i = 0; i < cc_count; i++) {
2339                     cap[0] = (p[0] == 0xff && field1) ? 0xfc : 0xfd;
2340                     cap[1] = p[1];
2341                     cap[2] = p[2];
2342                     cap[3] = (p[3] == 0xff && !field1) ? 0xfc : 0xfd;
2343                     cap[4] = p[4];
2344                     cap[5] = p[5];
2345                     cap += 6;
2346                     p += 6;
2347                 }
2348             }
2349             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
2350         }
2351         return 1;
2352     }
2353     return 0;
2354 }
2355
2356 static void mpeg_decode_user_data(AVCodecContext *avctx,
2357                                   const uint8_t *p, int buf_size)
2358 {
2359     Mpeg1Context *s = avctx->priv_data;
2360     const uint8_t *buf_end = p + buf_size;
2361     Mpeg1Context *s1 = avctx->priv_data;
2362
2363 #if 0
2364     int i;
2365     for(i=0; !(!p[i-2] && !p[i-1] && p[i]==1) && i<buf_size; i++){
2366         av_log(avctx, AV_LOG_ERROR, "%c", p[i]);
2367     }
2368     av_log(avctx, AV_LOG_ERROR, "\n");
2369 #endif
2370
2371     if (buf_size > 29){
2372         int i;
2373         for(i=0; i<20; i++)
2374             if (!memcmp(p+i, "\0TMPGEXS\0", 9)){
2375                 s->tmpgexs= 1;
2376             }
2377     }
2378     /* we parse the DTG active format information */
2379     if (buf_end - p >= 5 &&
2380         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2381         int flags = p[4];
2382         p += 5;
2383         if (flags & 0x80) {
2384             /* skip event id */
2385             p += 2;
2386         }
2387         if (flags & 0x40) {
2388             if (buf_end - p < 1)
2389                 return;
2390             s1->has_afd = 1;
2391             s1->afd     = p[0] & 0x0f;
2392         }
2393     } else if (buf_end - p >= 6 &&
2394                p[0] == 'J' && p[1] == 'P' && p[2] == '3' && p[3] == 'D' &&
2395                p[4] == 0x03) { // S3D_video_format_length
2396         // the 0x7F mask ignores the reserved_bit value
2397         const uint8_t S3D_video_format_type = p[5] & 0x7F;
2398
2399         if (S3D_video_format_type == 0x03 ||
2400             S3D_video_format_type == 0x04 ||
2401             S3D_video_format_type == 0x08 ||
2402             S3D_video_format_type == 0x23) {
2403
2404             s1->has_stereo3d = 1;
2405
2406             switch (S3D_video_format_type) {
2407             case 0x03:
2408                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE;
2409                 break;
2410             case 0x04:
2411                 s1->stereo3d.type = AV_STEREO3D_TOPBOTTOM;
2412                 break;
2413             case 0x08:
2414                 s1->stereo3d.type = AV_STEREO3D_2D;
2415                 break;
2416             case 0x23:
2417                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
2418                 break;
2419             }
2420         }
2421     } else if (mpeg_decode_a53_cc(avctx, p, buf_size)) {
2422         return;
2423     }
2424 }
2425
2426 static void mpeg_decode_gop(AVCodecContext *avctx,
2427                             const uint8_t *buf, int buf_size)
2428 {
2429     Mpeg1Context *s1  = avctx->priv_data;
2430     MpegEncContext *s = &s1->mpeg_enc_ctx;
2431     int broken_link;
2432     int64_t tc;
2433
2434     init_get_bits(&s->gb, buf, buf_size * 8);
2435
2436     tc = s-> timecode_frame_start = get_bits(&s->gb, 25);
2437
2438 #if FF_API_PRIVATE_OPT
2439 FF_DISABLE_DEPRECATION_WARNINGS
2440     avctx->timecode_frame_start = tc;
2441 FF_ENABLE_DEPRECATION_WARNINGS
2442 #endif
2443
2444     s->closed_gop = get_bits1(&s->gb);
2445     /* broken_link indicates that after editing the
2446      * reference frames of the first B-Frames after GOP I-Frame
2447      * are missing (open gop) */
2448     broken_link = get_bits1(&s->gb);
2449
2450     if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2451         char tcbuf[AV_TIMECODE_STR_SIZE];
2452         av_timecode_make_mpeg_tc_string(tcbuf, tc);
2453         av_log(s->avctx, AV_LOG_DEBUG,
2454                "GOP (%s) closed_gop=%d broken_link=%d\n",
2455                tcbuf, s->closed_gop, broken_link);
2456     }
2457 }
2458
2459 static int decode_chunks(AVCodecContext *avctx, AVFrame *picture,
2460                          int *got_output, const uint8_t *buf, int buf_size)
2461 {
2462     Mpeg1Context *s = avctx->priv_data;
2463     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2464     const uint8_t *buf_ptr = buf;
2465     const uint8_t *buf_end = buf + buf_size;
2466     int ret, input_size;
2467     int last_code = 0, skip_frame = 0;
2468     int picture_start_code_seen = 0;
2469
2470     for (;;) {
2471         /* find next start code */
2472         uint32_t start_code = -1;
2473         buf_ptr = avpriv_find_start_code(buf_ptr, buf_end, &start_code);
2474         if (start_code > 0x1ff) {
2475             if (!skip_frame) {
2476                 if (HAVE_THREADS &&
2477                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2478                     !avctx->hwaccel) {
2479                     int i;
2480                     av_assert0(avctx->thread_count > 1);
2481
2482                     avctx->execute(avctx, slice_decode_thread,
2483                                    &s2->thread_context[0], NULL,
2484                                    s->slice_count, sizeof(void *));
2485                     for (i = 0; i < s->slice_count; i++)
2486                         s2->er.error_count += s2->thread_context[i]->er.error_count;
2487                 }
2488
2489                 ret = slice_end(avctx, picture);
2490                 if (ret < 0)
2491                     return ret;
2492                 else if (ret) {
2493                     // FIXME: merge with the stuff in mpeg_decode_slice
2494                     if (s2->last_picture_ptr || s2->low_delay)
2495                         *got_output = 1;
2496                 }
2497             }
2498             s2->pict_type = 0;
2499
2500             if (avctx->err_recognition & AV_EF_EXPLODE && s2->er.error_count)
2501                 return AVERROR_INVALIDDATA;
2502
2503             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2504         }
2505
2506         input_size = buf_end - buf_ptr;
2507
2508         if (avctx->debug & FF_DEBUG_STARTCODE)
2509             av_log(avctx, AV_LOG_DEBUG, "%3"PRIX32" at %"PTRDIFF_SPECIFIER" left %d\n",
2510                    start_code, buf_ptr - buf, input_size);
2511
2512         /* prepare data for next start code */
2513         switch (start_code) {
2514         case SEQ_START_CODE:
2515             if (last_code == 0) {
2516                 mpeg1_decode_sequence(avctx, buf_ptr, input_size);
2517                 if (buf != avctx->extradata)
2518                     s->sync = 1;
2519             } else {
2520                 av_log(avctx, AV_LOG_ERROR,
2521                        "ignoring SEQ_START_CODE after %X\n", last_code);
2522                 if (avctx->err_recognition & AV_EF_EXPLODE)
2523                     return AVERROR_INVALIDDATA;
2524             }
2525             break;
2526
2527         case PICTURE_START_CODE:
2528             if (picture_start_code_seen && s2->picture_structure == PICT_FRAME) {
2529                /* If it's a frame picture, there can't be more than one picture header.
2530                   Yet, it does happen and we need to handle it. */
2531                av_log(avctx, AV_LOG_WARNING, "ignoring extra picture following a frame-picture\n");
2532                break;
2533             }
2534             picture_start_code_seen = 1;
2535
2536             if (s2->width <= 0 || s2->height <= 0) {
2537                 av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d.\n",
2538                        s2->width, s2->height);
2539                 return AVERROR_INVALIDDATA;
2540             }
2541
2542             if (s->tmpgexs){
2543                 s2->intra_dc_precision= 3;
2544                 s2->intra_matrix[0]= 1;
2545             }
2546             if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) &&
2547                 !avctx->hwaccel && s->slice_count) {
2548                 int i;
2549
2550                 avctx->execute(avctx, slice_decode_thread,
2551                                s2->thread_context, NULL,
2552                                s->slice_count, sizeof(void *));
2553                 for (i = 0; i < s->slice_count; i++)
2554                     s2->er.error_count += s2->thread_context[i]->er.error_count;
2555                 s->slice_count = 0;
2556             }
2557             if (last_code == 0 || last_code == SLICE_MIN_START_CODE) {
2558                 ret = mpeg_decode_postinit(avctx);
2559                 if (ret < 0) {
2560                     av_log(avctx, AV_LOG_ERROR,
2561                            "mpeg_decode_postinit() failure\n");
2562                     return ret;
2563                 }
2564
2565                 /* We have a complete image: we try to decompress it. */
2566                 if (mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0)
2567                     s2->pict_type = 0;
2568                 s->first_slice = 1;
2569                 last_code      = PICTURE_START_CODE;
2570             } else {
2571                 av_log(avctx, AV_LOG_ERROR,
2572                        "ignoring pic after %X\n", last_code);
2573                 if (avctx->err_recognition & AV_EF_EXPLODE)
2574                     return AVERROR_INVALIDDATA;
2575             }
2576             break;
2577         case EXT_START_CODE:
2578             init_get_bits(&s2->gb, buf_ptr, input_size * 8);
2579
2580             switch (get_bits(&s2->gb, 4)) {
2581             case 0x1:
2582                 if (last_code == 0) {
2583                     mpeg_decode_sequence_extension(s);
2584                 } else {
2585                     av_log(avctx, AV_LOG_ERROR,
2586                            "ignoring seq ext after %X\n", last_code);
2587                     if (avctx->err_recognition & AV_EF_EXPLODE)
2588                         return AVERROR_INVALIDDATA;
2589                 }
2590                 break;
2591             case 0x2:
2592                 mpeg_decode_sequence_display_extension(s);
2593                 break;
2594             case 0x3:
2595                 mpeg_decode_quant_matrix_extension(s2);
2596                 break;
2597             case 0x7:
2598                 mpeg_decode_picture_display_extension(s);
2599                 break;
2600             case 0x8:
2601                 if (last_code == PICTURE_START_CODE) {
2602                     mpeg_decode_picture_coding_extension(s);
2603                 } else {
2604                     av_log(avctx, AV_LOG_ERROR,
2605                            "ignoring pic cod ext after %X\n", last_code);
2606                     if (avctx->err_recognition & AV_EF_EXPLODE)
2607                         return AVERROR_INVALIDDATA;
2608                 }
2609                 break;
2610             }
2611             break;
2612         case USER_START_CODE:
2613             mpeg_decode_user_data(avctx, buf_ptr, input_size);
2614             break;
2615         case GOP_START_CODE:
2616             if (last_code == 0) {
2617                 s2->first_field = 0;
2618                 mpeg_decode_gop(avctx, buf_ptr, input_size);
2619                 s->sync = 1;
2620             } else {
2621                 av_log(avctx, AV_LOG_ERROR,
2622                        "ignoring GOP_START_CODE after %X\n", last_code);
2623                 if (avctx->err_recognition & AV_EF_EXPLODE)
2624                     return AVERROR_INVALIDDATA;
2625             }
2626             break;
2627         default:
2628             if (start_code >= SLICE_MIN_START_CODE &&
2629                 start_code <= SLICE_MAX_START_CODE && last_code == PICTURE_START_CODE) {
2630                 if (s2->progressive_sequence && !s2->progressive_frame) {
2631                     s2->progressive_frame = 1;
2632                     av_log(s2->avctx, AV_LOG_ERROR,
2633                            "interlaced frame in progressive sequence, ignoring\n");
2634                 }
2635
2636                 if (s2->picture_structure == 0 ||
2637                     (s2->progressive_frame && s2->picture_structure != PICT_FRAME)) {
2638                     av_log(s2->avctx, AV_LOG_ERROR,
2639                            "picture_structure %d invalid, ignoring\n",
2640                            s2->picture_structure);
2641                     s2->picture_structure = PICT_FRAME;
2642                 }
2643
2644                 if (s2->progressive_sequence && !s2->frame_pred_frame_dct)
2645                     av_log(s2->avctx, AV_LOG_WARNING, "invalid frame_pred_frame_dct\n");
2646
2647                 if (s2->picture_structure == PICT_FRAME) {
2648                     s2->first_field = 0;
2649                     s2->v_edge_pos  = 16 * s2->mb_height;
2650                 } else {
2651                     s2->first_field ^= 1;
2652                     s2->v_edge_pos   = 8 * s2->mb_height;
2653                     memset(s2->mbskip_table, 0, s2->mb_stride * s2->mb_height);
2654                 }
2655             }
2656             if (start_code >= SLICE_MIN_START_CODE &&
2657                 start_code <= SLICE_MAX_START_CODE && last_code != 0) {
2658                 const int field_pic = s2->picture_structure != PICT_FRAME;
2659                 int mb_y = start_code - SLICE_MIN_START_CODE;
2660                 last_code = SLICE_MIN_START_CODE;
2661                 if (s2->codec_id != AV_CODEC_ID_MPEG1VIDEO && s2->mb_height > 2800/16)
2662                     mb_y += (*buf_ptr&0xE0)<<2;
2663
2664                 mb_y <<= field_pic;
2665                 if (s2->picture_structure == PICT_BOTTOM_FIELD)
2666                     mb_y++;
2667
2668                 if (buf_end - buf_ptr < 2) {
2669                     av_log(s2->avctx, AV_LOG_ERROR, "slice too small\n");
2670                     return AVERROR_INVALIDDATA;
2671                 }
2672
2673                 if (mb_y >= s2->mb_height) {
2674                     av_log(s2->avctx, AV_LOG_ERROR,
2675                            "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2676                     return AVERROR_INVALIDDATA;
2677                 }
2678
2679                 if (!s2->last_picture_ptr) {
2680                     /* Skip B-frames if we do not have reference frames and
2681                      * GOP is not closed. */
2682                     if (s2->pict_type == AV_PICTURE_TYPE_B) {
2683                         if (!s2->closed_gop) {
2684                             skip_frame = 1;
2685                             av_log(s2->avctx, AV_LOG_DEBUG,
2686                                    "Skipping B slice due to open GOP\n");
2687                             break;
2688                         }
2689                     }
2690                 }
2691                 if (s2->pict_type == AV_PICTURE_TYPE_I || (s2->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL))
2692                     s->sync = 1;
2693                 if (!s2->next_picture_ptr) {
2694                     /* Skip P-frames if we do not have a reference frame or
2695                      * we have an invalid header. */
2696                     if (s2->pict_type == AV_PICTURE_TYPE_P && !s->sync) {
2697                         skip_frame = 1;
2698                         av_log(s2->avctx, AV_LOG_DEBUG,
2699                                "Skipping P slice due to !sync\n");
2700                         break;
2701                     }
2702                 }
2703                 if ((avctx->skip_frame >= AVDISCARD_NONREF &&
2704                      s2->pict_type == AV_PICTURE_TYPE_B) ||
2705                     (avctx->skip_frame >= AVDISCARD_NONKEY &&
2706                      s2->pict_type != AV_PICTURE_TYPE_I) ||
2707                     avctx->skip_frame >= AVDISCARD_ALL) {
2708                     skip_frame = 1;
2709                     break;
2710                 }
2711
2712                 if (!s->mpeg_enc_ctx_allocated)
2713                     break;
2714
2715                 if (s2->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
2716                     if (mb_y < avctx->skip_top ||
2717                         mb_y >= s2->mb_height - avctx->skip_bottom)
2718                         break;
2719                 }
2720
2721                 if (!s2->pict_type) {
2722                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2723                     if (avctx->err_recognition & AV_EF_EXPLODE)
2724                         return AVERROR_INVALIDDATA;
2725                     break;
2726                 }
2727
2728                 if (s->first_slice) {
2729                     skip_frame     = 0;
2730                     s->first_slice = 0;
2731                     if ((ret = mpeg_field_start(s2, buf, buf_size)) < 0)
2732                         return ret;
2733                 }
2734                 if (!s2->current_picture_ptr) {
2735                     av_log(avctx, AV_LOG_ERROR,
2736                            "current_picture not initialized\n");
2737                     return AVERROR_INVALIDDATA;
2738                 }
2739
2740                 if (HAVE_THREADS &&
2741                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2742                     !avctx->hwaccel) {
2743                     int threshold = (s2->mb_height * s->slice_count +
2744                                      s2->slice_context_count / 2) /
2745                                     s2->slice_context_count;
2746                     av_assert0(avctx->thread_count > 1);
2747                     if (threshold <= mb_y) {
2748                         MpegEncContext *thread_context = s2->thread_context[s->slice_count];
2749
2750                         thread_context->start_mb_y = mb_y;
2751                         thread_context->end_mb_y   = s2->mb_height;
2752                         if (s->slice_count) {
2753                             s2->thread_context[s->slice_count - 1]->end_mb_y = mb_y;
2754                             ret = ff_update_duplicate_context(thread_context, s2);
2755                             if (ret < 0)
2756                                 return ret;
2757                         }
2758                         init_get_bits(&thread_context->gb, buf_ptr, input_size * 8);
2759                         s->slice_count++;
2760                     }
2761                     buf_ptr += 2; // FIXME add minimum number of bytes per slice
2762                 } else {
2763                     ret = mpeg_decode_slice(s2, mb_y, &buf_ptr, input_size);
2764                     emms_c();
2765
2766                     if (ret < 0) {
2767                         if (avctx->err_recognition & AV_EF_EXPLODE)
2768                             return ret;
2769                         if (s2->resync_mb_x >= 0 && s2->resync_mb_y >= 0)
2770                             ff_er_add_slice(&s2->er, s2->resync_mb_x,
2771                                             s2->resync_mb_y, s2->mb_x, s2->mb_y,
2772                                             ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2773                     } else {
2774                         ff_er_add_slice(&s2->er, s2->resync_mb_x,
2775                                         s2->resync_mb_y, s2->mb_x - 1, s2->mb_y,
2776                                         ER_AC_END | ER_DC_END | ER_MV_END);
2777                     }
2778                 }
2779             }
2780             break;
2781         }
2782     }
2783 }
2784
2785 static int mpeg_decode_frame(AVCodecContext *avctx, void *data,
2786                              int *got_output, AVPacket *avpkt)
2787 {
2788     const uint8_t *buf = avpkt->data;
2789     int ret;
2790     int buf_size = avpkt->size;
2791     Mpeg1Context *s = avctx->priv_data;
2792     AVFrame *picture = data;
2793     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2794
2795     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2796         /* special case for last picture */
2797         if (s2->low_delay == 0 && s2->next_picture_ptr) {
2798             int ret = av_frame_ref(picture, s2->next_picture_ptr->f);
2799             if (ret < 0)
2800                 return ret;
2801
2802             s2->next_picture_ptr = NULL;
2803
2804             *got_output = 1;
2805         }
2806         return buf_size;
2807     }
2808
2809     if (s2->avctx->flags & AV_CODEC_FLAG_TRUNCATED) {
2810         int next = ff_mpeg1_find_frame_end(&s2->parse_context, buf,
2811                                            buf_size, NULL);
2812
2813         if (ff_combine_frame(&s2->parse_context, next,
2814                              (const uint8_t **) &buf, &buf_size) < 0)
2815             return buf_size;
2816     }
2817
2818     s2->codec_tag = avpriv_toupper4(avctx->codec_tag);
2819     if (s->mpeg_enc_ctx_allocated == 0 && (   s2->codec_tag == AV_RL32("VCR2")
2820                                            || s2->codec_tag == AV_RL32("BW10")
2821                                           ))
2822         vcr2_init_sequence(avctx);
2823
2824     s->slice_count = 0;
2825
2826     if (avctx->extradata && !s->extradata_decoded) {
2827         ret = decode_chunks(avctx, picture, got_output,
2828                             avctx->extradata, avctx->extradata_size);
2829         if (*got_output) {
2830             av_log(avctx, AV_LOG_ERROR, "picture in extradata\n");
2831             av_frame_unref(picture);
2832             *got_output = 0;
2833         }
2834         s->extradata_decoded = 1;
2835         if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) {
2836             s2->current_picture_ptr = NULL;
2837             return ret;
2838         }
2839     }
2840
2841     ret = decode_chunks(avctx, picture, got_output, buf, buf_size);
2842     if (ret<0 || *got_output) {
2843         s2->current_picture_ptr = NULL;
2844
2845         if (s2->timecode_frame_start != -1 && *got_output) {
2846             AVFrameSideData *tcside = av_frame_new_side_data(picture,
2847                                                              AV_FRAME_DATA_GOP_TIMECODE,
2848                                                              sizeof(int64_t));
2849             if (!tcside)
2850                 return AVERROR(ENOMEM);
2851             memcpy(tcside->data, &s2->timecode_frame_start, sizeof(int64_t));
2852
2853             s2->timecode_frame_start = -1;
2854         }
2855     }
2856
2857     return ret;
2858 }
2859
2860 static void flush(AVCodecContext *avctx)
2861 {
2862     Mpeg1Context *s = avctx->priv_data;
2863
2864     s->sync       = 0;
2865
2866     ff_mpeg_flush(avctx);
2867 }
2868
2869 static av_cold int mpeg_decode_end(AVCodecContext *avctx)
2870 {
2871     Mpeg1Context *s = avctx->priv_data;
2872
2873     if (s->mpeg_enc_ctx_allocated)
2874         ff_mpv_common_end(&s->mpeg_enc_ctx);
2875     av_freep(&s->a53_caption);
2876     return 0;
2877 }
2878
2879 AVCodec ff_mpeg1video_decoder = {
2880     .name                  = "mpeg1video",
2881     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2882     .type                  = AVMEDIA_TYPE_VIDEO,
2883     .id                    = AV_CODEC_ID_MPEG1VIDEO,
2884     .priv_data_size        = sizeof(Mpeg1Context),
2885     .init                  = mpeg_decode_init,
2886     .close                 = mpeg_decode_end,
2887     .decode                = mpeg_decode_frame,
2888     .capabilities          = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2889                              AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2890                              AV_CODEC_CAP_SLICE_THREADS,
2891     .caps_internal         = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
2892     .flush                 = flush,
2893     .max_lowres            = 3,
2894     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context),
2895     .hw_configs            = (const AVCodecHWConfigInternal*[]) {
2896 #if CONFIG_MPEG1_NVDEC_HWACCEL
2897                                HWACCEL_NVDEC(mpeg1),
2898 #endif
2899 #if CONFIG_MPEG1_VDPAU_HWACCEL
2900                                HWACCEL_VDPAU(mpeg1),
2901 #endif
2902 #if CONFIG_MPEG1_VIDEOTOOLBOX_HWACCEL
2903                                HWACCEL_VIDEOTOOLBOX(mpeg1),
2904 #endif
2905 #if CONFIG_MPEG1_XVMC_HWACCEL
2906                                HWACCEL_XVMC(mpeg1),
2907 #endif
2908                                NULL
2909                            },
2910 };
2911
2912 AVCodec ff_mpeg2video_decoder = {
2913     .name           = "mpeg2video",
2914     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2915     .type           = AVMEDIA_TYPE_VIDEO,
2916     .id             = AV_CODEC_ID_MPEG2VIDEO,
2917     .priv_data_size = sizeof(Mpeg1Context),
2918     .init           = mpeg_decode_init,
2919     .close          = mpeg_decode_end,
2920     .decode         = mpeg_decode_frame,
2921     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2922                       AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2923                       AV_CODEC_CAP_SLICE_THREADS,
2924     .caps_internal  = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
2925     .flush          = flush,
2926     .max_lowres     = 3,
2927     .profiles       = NULL_IF_CONFIG_SMALL(ff_mpeg2_video_profiles),
2928     .hw_configs     = (const AVCodecHWConfigInternal*[]) {
2929 #if CONFIG_MPEG2_DXVA2_HWACCEL
2930                         HWACCEL_DXVA2(mpeg2),
2931 #endif
2932 #if CONFIG_MPEG2_D3D11VA_HWACCEL
2933                         HWACCEL_D3D11VA(mpeg2),
2934 #endif
2935 #if CONFIG_MPEG2_D3D11VA2_HWACCEL
2936                         HWACCEL_D3D11VA2(mpeg2),
2937 #endif
2938 #if CONFIG_MPEG2_NVDEC_HWACCEL
2939                         HWACCEL_NVDEC(mpeg2),
2940 #endif
2941 #if CONFIG_MPEG2_VAAPI_HWACCEL
2942                         HWACCEL_VAAPI(mpeg2),
2943 #endif
2944 #if CONFIG_MPEG2_VDPAU_HWACCEL
2945                         HWACCEL_VDPAU(mpeg2),
2946 #endif
2947 #if CONFIG_MPEG2_VIDEOTOOLBOX_HWACCEL
2948                         HWACCEL_VIDEOTOOLBOX(mpeg2),
2949 #endif
2950 #if CONFIG_MPEG2_XVMC_HWACCEL
2951                         HWACCEL_XVMC(mpeg2),
2952 #endif
2953                         NULL
2954                     },
2955 };
2956
2957 //legacy decoder
2958 AVCodec ff_mpegvideo_decoder = {
2959     .name           = "mpegvideo",
2960     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2961     .type           = AVMEDIA_TYPE_VIDEO,
2962     .id             = AV_CODEC_ID_MPEG2VIDEO,
2963     .priv_data_size = sizeof(Mpeg1Context),
2964     .init           = mpeg_decode_init,
2965     .close          = mpeg_decode_end,
2966     .decode         = mpeg_decode_frame,
2967     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS,
2968     .caps_internal  = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
2969     .flush          = flush,
2970     .max_lowres     = 3,
2971 };