d5bc5f21b2ade337ff2be6a517e6808bcf3e3e2c
[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 "idctdsp.h"
40 #include "internal.h"
41 #include "mpeg_er.h"
42 #include "mpeg12.h"
43 #include "mpeg12data.h"
44 #include "mpegutils.h"
45 #include "mpegvideo.h"
46 #include "mpegvideodata.h"
47 #include "profiles.h"
48 #include "thread.h"
49 #include "version.h"
50 #include "xvmc_internal.h"
51
52 typedef struct Mpeg1Context {
53     MpegEncContext mpeg_enc_ctx;
54     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
55     int repeat_field;           /* true if we must repeat the field */
56     AVPanScan pan_scan;         /* some temporary storage for the panscan */
57     AVStereo3D stereo3d;
58     int has_stereo3d;
59     uint8_t *a53_caption;
60     int a53_caption_size;
61     uint8_t afd;
62     int has_afd;
63     int slice_count;
64     AVRational save_aspect;
65     int save_width, save_height, save_progressive_seq;
66     AVRational frame_rate_ext;  /* MPEG-2 specific framerate modificator */
67     int sync;                   /* Did we reach a sync point like a GOP/SEQ/KEYFrame? */
68     int tmpgexs;
69     int first_slice;
70     int extradata_decoded;
71 } Mpeg1Context;
72
73 #define MB_TYPE_ZERO_MV   0x20000000
74
75 static const uint32_t ptype2mb_type[7] = {
76                     MB_TYPE_INTRA,
77                     MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_ZERO_MV | MB_TYPE_16x16,
78                     MB_TYPE_L0,
79                     MB_TYPE_L0 | MB_TYPE_CBP,
80     MB_TYPE_QUANT | MB_TYPE_INTRA,
81     MB_TYPE_QUANT | MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_ZERO_MV | MB_TYPE_16x16,
82     MB_TYPE_QUANT | MB_TYPE_L0 | MB_TYPE_CBP,
83 };
84
85 static const uint32_t btype2mb_type[11] = {
86                     MB_TYPE_INTRA,
87                     MB_TYPE_L1,
88                     MB_TYPE_L1   | MB_TYPE_CBP,
89                     MB_TYPE_L0,
90                     MB_TYPE_L0   | MB_TYPE_CBP,
91                     MB_TYPE_L0L1,
92                     MB_TYPE_L0L1 | MB_TYPE_CBP,
93     MB_TYPE_QUANT | MB_TYPE_INTRA,
94     MB_TYPE_QUANT | MB_TYPE_L1   | MB_TYPE_CBP,
95     MB_TYPE_QUANT | MB_TYPE_L0   | MB_TYPE_CBP,
96     MB_TYPE_QUANT | MB_TYPE_L0L1 | MB_TYPE_CBP,
97 };
98
99 /* as H.263, but only 17 codes */
100 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
101 {
102     int code, sign, val, shift;
103
104     code = get_vlc2(&s->gb, ff_mv_vlc.table, MV_VLC_BITS, 2);
105     if (code == 0)
106         return pred;
107     if (code < 0)
108         return 0xffff;
109
110     sign  = get_bits1(&s->gb);
111     shift = fcode - 1;
112     val   = code;
113     if (shift) {
114         val  = (val - 1) << shift;
115         val |= get_bits(&s->gb, shift);
116         val++;
117     }
118     if (sign)
119         val = -val;
120     val += pred;
121
122     /* modulo decoding */
123     return sign_extend(val, 5 + shift);
124 }
125
126 #define MAX_INDEX (64 - 1)
127 #define check_scantable_index(ctx, x)                                         \
128     do {                                                                      \
129         if ((x) > MAX_INDEX) {                                                \
130             av_log(ctx->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n",     \
131                    ctx->mb_x, ctx->mb_y);                                     \
132             return AVERROR_INVALIDDATA;                                       \
133         }                                                                     \
134     } while (0)
135
136 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
137                                            int16_t *block, int n)
138 {
139     int level, i, j, run;
140     RLTable *rl                  = &ff_rl_mpeg1;
141     uint8_t *const scantable     = s->intra_scantable.permutated;
142     const uint16_t *quant_matrix = s->inter_matrix;
143     const int qscale             = s->qscale;
144
145     {
146         OPEN_READER(re, &s->gb);
147         i = -1;
148         // special case for first coefficient, no need to add second VLC table
149         UPDATE_CACHE(re, &s->gb);
150         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
151             level = (3 * qscale * quant_matrix[0]) >> 5;
152             level = (level - 1) | 1;
153             if (GET_CACHE(re, &s->gb) & 0x40000000)
154                 level = -level;
155             block[0] = level;
156             i++;
157             SKIP_BITS(re, &s->gb, 2);
158             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
159                 goto end;
160         }
161         /* now quantify & encode AC coefficients */
162         for (;;) {
163             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
164                        TEX_VLC_BITS, 2, 0);
165
166             if (level != 0) {
167                 i += run;
168                 if (i > MAX_INDEX)
169                     break;
170                 j = scantable[i];
171                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
172                 level = (level - 1) | 1;
173                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
174                         SHOW_SBITS(re, &s->gb, 1);
175                 SKIP_BITS(re, &s->gb, 1);
176             } else {
177                 /* escape */
178                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
179                 LAST_SKIP_BITS(re, &s->gb, 6);
180                 UPDATE_CACHE(re, &s->gb);
181                 level = SHOW_SBITS(re, &s->gb, 8);
182                 SKIP_BITS(re, &s->gb, 8);
183                 if (level == -128) {
184                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
185                     SKIP_BITS(re, &s->gb, 8);
186                 } else if (level == 0) {
187                     level = SHOW_UBITS(re, &s->gb, 8);
188                     SKIP_BITS(re, &s->gb, 8);
189                 }
190                 i += run;
191                 if (i > MAX_INDEX)
192                     break;
193                 j = scantable[i];
194                 if (level < 0) {
195                     level = -level;
196                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
197                     level = (level - 1) | 1;
198                     level = -level;
199                 } else {
200                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
201                     level = (level - 1) | 1;
202                 }
203             }
204
205             block[j] = level;
206             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
207                 break;
208             UPDATE_CACHE(re, &s->gb);
209         }
210 end:
211         LAST_SKIP_BITS(re, &s->gb, 2);
212         CLOSE_READER(re, &s->gb);
213     }
214
215     check_scantable_index(s, i);
216
217     s->block_last_index[n] = i;
218     return 0;
219 }
220
221 /**
222  * Note: this function can read out of range and crash for corrupt streams.
223  * Changing this would eat up any speed benefits it has.
224  * Do not use "fast" flag if you need the code to be robust.
225  */
226 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s,
227                                                 int16_t *block, int n)
228 {
229     int level, i, j, run;
230     RLTable *rl              = &ff_rl_mpeg1;
231     uint8_t *const scantable = s->intra_scantable.permutated;
232     const int qscale         = s->qscale;
233
234     {
235         OPEN_READER(re, &s->gb);
236         i = -1;
237         // Special case for first coefficient, no need to add second VLC table.
238         UPDATE_CACHE(re, &s->gb);
239         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
240             level = (3 * qscale) >> 1;
241             level = (level - 1) | 1;
242             if (GET_CACHE(re, &s->gb) & 0x40000000)
243                 level = -level;
244             block[0] = level;
245             i++;
246             SKIP_BITS(re, &s->gb, 2);
247             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
248                 goto end;
249         }
250
251         /* now quantify & encode AC coefficients */
252         for (;;) {
253             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
254                        TEX_VLC_BITS, 2, 0);
255
256             if (level != 0) {
257                 i += run;
258                 if (i > MAX_INDEX)
259                     break;
260                 j = scantable[i];
261                 level = ((level * 2 + 1) * qscale) >> 1;
262                 level = (level - 1) | 1;
263                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
264                         SHOW_SBITS(re, &s->gb, 1);
265                 SKIP_BITS(re, &s->gb, 1);
266             } else {
267                 /* escape */
268                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
269                 LAST_SKIP_BITS(re, &s->gb, 6);
270                 UPDATE_CACHE(re, &s->gb);
271                 level = SHOW_SBITS(re, &s->gb, 8);
272                 SKIP_BITS(re, &s->gb, 8);
273                 if (level == -128) {
274                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
275                     SKIP_BITS(re, &s->gb, 8);
276                 } else if (level == 0) {
277                     level = SHOW_UBITS(re, &s->gb, 8);
278                     SKIP_BITS(re, &s->gb, 8);
279                 }
280                 i += run;
281                 if (i > MAX_INDEX)
282                     break;
283                 j = scantable[i];
284                 if (level < 0) {
285                     level = -level;
286                     level = ((level * 2 + 1) * qscale) >> 1;
287                     level = (level - 1) | 1;
288                     level = -level;
289                 } else {
290                     level = ((level * 2 + 1) * qscale) >> 1;
291                     level = (level - 1) | 1;
292                 }
293             }
294
295             block[j] = level;
296             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
297                 break;
298             UPDATE_CACHE(re, &s->gb);
299         }
300 end:
301         LAST_SKIP_BITS(re, &s->gb, 2);
302         CLOSE_READER(re, &s->gb);
303     }
304
305     check_scantable_index(s, i);
306
307     s->block_last_index[n] = i;
308     return 0;
309 }
310
311 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
312                                                int16_t *block, int n)
313 {
314     int level, i, j, run;
315     RLTable *rl = &ff_rl_mpeg1;
316     uint8_t *const scantable = s->intra_scantable.permutated;
317     const uint16_t *quant_matrix;
318     const int qscale = s->qscale;
319     int mismatch;
320
321     mismatch = 1;
322
323     {
324         OPEN_READER(re, &s->gb);
325         i = -1;
326         if (n < 4)
327             quant_matrix = s->inter_matrix;
328         else
329             quant_matrix = s->chroma_inter_matrix;
330
331         // Special case for first coefficient, no need to add second VLC table.
332         UPDATE_CACHE(re, &s->gb);
333         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
334             level = (3 * qscale * quant_matrix[0]) >> 5;
335             if (GET_CACHE(re, &s->gb) & 0x40000000)
336                 level = -level;
337             block[0]  = level;
338             mismatch ^= level;
339             i++;
340             SKIP_BITS(re, &s->gb, 2);
341             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
342                 goto end;
343         }
344
345         /* now quantify & encode AC coefficients */
346         for (;;) {
347             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
348                        TEX_VLC_BITS, 2, 0);
349
350             if (level != 0) {
351                 i += run;
352                 if (i > MAX_INDEX)
353                     break;
354                 j = scantable[i];
355                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
356                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
357                         SHOW_SBITS(re, &s->gb, 1);
358                 SKIP_BITS(re, &s->gb, 1);
359             } else {
360                 /* escape */
361                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
362                 LAST_SKIP_BITS(re, &s->gb, 6);
363                 UPDATE_CACHE(re, &s->gb);
364                 level = SHOW_SBITS(re, &s->gb, 12);
365                 SKIP_BITS(re, &s->gb, 12);
366
367                 i += run;
368                 if (i > MAX_INDEX)
369                     break;
370                 j = scantable[i];
371                 if (level < 0) {
372                     level = ((-level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
373                     level = -level;
374                 } else {
375                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
376                 }
377             }
378
379             mismatch ^= level;
380             block[j]  = level;
381             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
382                 break;
383             UPDATE_CACHE(re, &s->gb);
384         }
385 end:
386         LAST_SKIP_BITS(re, &s->gb, 2);
387         CLOSE_READER(re, &s->gb);
388     }
389     block[63] ^= (mismatch & 1);
390
391     check_scantable_index(s, i);
392
393     s->block_last_index[n] = i;
394     return 0;
395 }
396
397 /**
398  * Note: this function can read out of range and crash for corrupt streams.
399  * Changing this would eat up any speed benefits it has.
400  * Do not use "fast" flag if you need the code to be robust.
401  */
402 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
403                                                     int16_t *block, int n)
404 {
405     int level, i, j, run;
406     RLTable *rl              = &ff_rl_mpeg1;
407     uint8_t *const scantable = s->intra_scantable.permutated;
408     const int qscale         = s->qscale;
409     OPEN_READER(re, &s->gb);
410     i = -1;
411
412     // special case for first coefficient, no need to add second VLC table
413     UPDATE_CACHE(re, &s->gb);
414     if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
415         level = (3 * qscale) >> 1;
416         if (GET_CACHE(re, &s->gb) & 0x40000000)
417             level = -level;
418         block[0] = level;
419         i++;
420         SKIP_BITS(re, &s->gb, 2);
421         if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
422             goto end;
423     }
424
425     /* now quantify & encode AC coefficients */
426     for (;;) {
427         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
428
429         if (level != 0) {
430             i += run;
431             if (i > MAX_INDEX)
432                 break;
433             j = scantable[i];
434             level = ((level * 2 + 1) * qscale) >> 1;
435             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
436                     SHOW_SBITS(re, &s->gb, 1);
437             SKIP_BITS(re, &s->gb, 1);
438         } else {
439             /* escape */
440             run = SHOW_UBITS(re, &s->gb, 6) + 1;
441             LAST_SKIP_BITS(re, &s->gb, 6);
442             UPDATE_CACHE(re, &s->gb);
443             level = SHOW_SBITS(re, &s->gb, 12);
444             SKIP_BITS(re, &s->gb, 12);
445
446             i += run;
447             if (i > MAX_INDEX)
448                 break;
449             j = scantable[i];
450             if (level < 0) {
451                 level = ((-level * 2 + 1) * qscale) >> 1;
452                 level = -level;
453             } else {
454                 level = ((level * 2 + 1) * qscale) >> 1;
455             }
456         }
457
458         block[j] = level;
459         if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF || i > 63)
460             break;
461
462         UPDATE_CACHE(re, &s->gb);
463     }
464 end:
465     LAST_SKIP_BITS(re, &s->gb, 2);
466     CLOSE_READER(re, &s->gb);
467
468     check_scantable_index(s, i);
469
470     s->block_last_index[n] = i;
471     return 0;
472 }
473
474 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
475                                            int16_t *block, int n)
476 {
477     int level, dc, diff, i, j, run;
478     int component;
479     RLTable *rl;
480     uint8_t *const scantable = s->intra_scantable.permutated;
481     const uint16_t *quant_matrix;
482     const int qscale = s->qscale;
483     int mismatch;
484
485     /* DC coefficient */
486     if (n < 4) {
487         quant_matrix = s->intra_matrix;
488         component    = 0;
489     } else {
490         quant_matrix = s->chroma_intra_matrix;
491         component    = (n & 1) + 1;
492     }
493     diff = decode_dc(&s->gb, component);
494     if (diff >= 0xffff)
495         return AVERROR_INVALIDDATA;
496     dc  = s->last_dc[component];
497     dc += diff;
498     s->last_dc[component] = dc;
499     block[0] = dc * (1 << (3 - s->intra_dc_precision));
500     ff_tlog(s->avctx, "dc=%d\n", block[0]);
501     mismatch = block[0] ^ 1;
502     i = 0;
503     if (s->intra_vlc_format)
504         rl = &ff_rl_mpeg2;
505     else
506         rl = &ff_rl_mpeg1;
507
508     {
509         OPEN_READER(re, &s->gb);
510         /* now quantify & encode AC coefficients */
511         for (;;) {
512             UPDATE_CACHE(re, &s->gb);
513             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
514                        TEX_VLC_BITS, 2, 0);
515
516             if (level == 127) {
517                 break;
518             } else if (level != 0) {
519                 i += run;
520                 if (i > MAX_INDEX)
521                     break;
522                 j = scantable[i];
523                 level = (level * qscale * quant_matrix[j]) >> 4;
524                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
525                         SHOW_SBITS(re, &s->gb, 1);
526                 LAST_SKIP_BITS(re, &s->gb, 1);
527             } else {
528                 /* escape */
529                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
530                 LAST_SKIP_BITS(re, &s->gb, 6);
531                 UPDATE_CACHE(re, &s->gb);
532                 level = SHOW_SBITS(re, &s->gb, 12);
533                 SKIP_BITS(re, &s->gb, 12);
534                 i += run;
535                 if (i > MAX_INDEX)
536                     break;
537                 j = scantable[i];
538                 if (level < 0) {
539                     level = (-level * qscale * quant_matrix[j]) >> 4;
540                     level = -level;
541                 } else {
542                     level = (level * qscale * quant_matrix[j]) >> 4;
543                 }
544             }
545
546             mismatch ^= level;
547             block[j]  = level;
548         }
549         CLOSE_READER(re, &s->gb);
550     }
551     block[63] ^= mismatch & 1;
552
553     check_scantable_index(s, i);
554
555     s->block_last_index[n] = i;
556     return 0;
557 }
558
559 /**
560  * Note: this function can read out of range and crash for corrupt streams.
561  * Changing this would eat up any speed benefits it has.
562  * Do not use "fast" flag if you need the code to be robust.
563  */
564 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
565                                                 int16_t *block, int n)
566 {
567     int level, dc, diff, i, j, run;
568     int component;
569     RLTable *rl;
570     uint8_t *const scantable = s->intra_scantable.permutated;
571     const uint16_t *quant_matrix;
572     const int qscale = s->qscale;
573
574     /* DC coefficient */
575     if (n < 4) {
576         quant_matrix = s->intra_matrix;
577         component    = 0;
578     } else {
579         quant_matrix = s->chroma_intra_matrix;
580         component    = (n & 1) + 1;
581     }
582     diff = decode_dc(&s->gb, component);
583     if (diff >= 0xffff)
584         return AVERROR_INVALIDDATA;
585     dc = s->last_dc[component];
586     dc += diff;
587     s->last_dc[component] = dc;
588     block[0] = dc << (3 - s->intra_dc_precision);
589     i = 0;
590     if (s->intra_vlc_format)
591         rl = &ff_rl_mpeg2;
592     else
593         rl = &ff_rl_mpeg1;
594
595     {
596         OPEN_READER(re, &s->gb);
597         /* now quantify & encode AC coefficients */
598         for (;;) {
599             UPDATE_CACHE(re, &s->gb);
600             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
601                        TEX_VLC_BITS, 2, 0);
602
603             if (level >= 64 || i > 63) {
604                 break;
605             } else if (level != 0) {
606                 i += run;
607                 j = scantable[i];
608                 level = (level * qscale * quant_matrix[j]) >> 4;
609                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
610                         SHOW_SBITS(re, &s->gb, 1);
611                 LAST_SKIP_BITS(re, &s->gb, 1);
612             } else {
613                 /* escape */
614                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
615                 LAST_SKIP_BITS(re, &s->gb, 6);
616                 UPDATE_CACHE(re, &s->gb);
617                 level = SHOW_SBITS(re, &s->gb, 12);
618                 SKIP_BITS(re, &s->gb, 12);
619                 i += run;
620                 j = scantable[i];
621                 if (level < 0) {
622                     level = (-level * qscale * quant_matrix[j]) >> 4;
623                     level = -level;
624                 } else {
625                     level = (level * qscale * quant_matrix[j]) >> 4;
626                 }
627             }
628
629             block[j] = level;
630         }
631         CLOSE_READER(re, &s->gb);
632     }
633
634     check_scantable_index(s, i);
635
636     s->block_last_index[n] = i;
637     return 0;
638 }
639
640 /******************************************/
641 /* decoding */
642
643 static inline int get_dmv(MpegEncContext *s)
644 {
645     if (get_bits1(&s->gb))
646         return 1 - (get_bits1(&s->gb) << 1);
647     else
648         return 0;
649 }
650
651 static inline int get_qscale(MpegEncContext *s)
652 {
653     int qscale = get_bits(&s->gb, 5);
654     if (s->q_scale_type)
655         return ff_mpeg2_non_linear_qscale[qscale];
656     else
657         return qscale << 1;
658 }
659
660
661 /* motion type (for MPEG-2) */
662 #define MT_FIELD 1
663 #define MT_FRAME 2
664 #define MT_16X8  2
665 #define MT_DMV   3
666
667 static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
668 {
669     int i, j, k, cbp, val, mb_type, motion_type;
670     const int mb_block_count = 4 + (1 << s->chroma_format);
671     int ret;
672
673     ff_tlog(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
674
675     av_assert2(s->mb_skipped == 0);
676
677     if (s->mb_skip_run-- != 0) {
678         if (s->pict_type == AV_PICTURE_TYPE_P) {
679             s->mb_skipped = 1;
680             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
681                 MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
682         } else {
683             int mb_type;
684
685             if (s->mb_x)
686                 mb_type = s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride - 1];
687             else
688                 // FIXME not sure if this is allowed in MPEG at all
689                 mb_type = s->current_picture.mb_type[s->mb_width + (s->mb_y - 1) * s->mb_stride - 1];
690             if (IS_INTRA(mb_type)) {
691                 av_log(s->avctx, AV_LOG_ERROR, "skip with previntra\n");
692                 return AVERROR_INVALIDDATA;
693             }
694             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
695                 mb_type | MB_TYPE_SKIP;
696
697             if ((s->mv[0][0][0] | s->mv[0][0][1] | s->mv[1][0][0] | s->mv[1][0][1]) == 0)
698                 s->mb_skipped = 1;
699         }
700
701         return 0;
702     }
703
704     switch (s->pict_type) {
705     default:
706     case AV_PICTURE_TYPE_I:
707         if (get_bits1(&s->gb) == 0) {
708             if (get_bits1(&s->gb) == 0) {
709                 av_log(s->avctx, AV_LOG_ERROR,
710                        "Invalid mb type in I-frame at %d %d\n",
711                        s->mb_x, s->mb_y);
712                 return AVERROR_INVALIDDATA;
713             }
714             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
715         } else {
716             mb_type = MB_TYPE_INTRA;
717         }
718         break;
719     case AV_PICTURE_TYPE_P:
720         mb_type = get_vlc2(&s->gb, ff_mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
721         if (mb_type < 0) {
722             av_log(s->avctx, AV_LOG_ERROR,
723                    "Invalid mb type in P-frame at %d %d\n", s->mb_x, s->mb_y);
724             return AVERROR_INVALIDDATA;
725         }
726         mb_type = ptype2mb_type[mb_type];
727         break;
728     case AV_PICTURE_TYPE_B:
729         mb_type = get_vlc2(&s->gb, ff_mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
730         if (mb_type < 0) {
731             av_log(s->avctx, AV_LOG_ERROR,
732                    "Invalid mb type in B-frame at %d %d\n", s->mb_x, s->mb_y);
733             return AVERROR_INVALIDDATA;
734         }
735         mb_type = btype2mb_type[mb_type];
736         break;
737     }
738     ff_tlog(s->avctx, "mb_type=%x\n", mb_type);
739 //    motion_type = 0; /* avoid warning */
740     if (IS_INTRA(mb_type)) {
741         s->bdsp.clear_blocks(s->block[0]);
742
743         if (!s->chroma_y_shift)
744             s->bdsp.clear_blocks(s->block[6]);
745
746         /* compute DCT type */
747         // FIXME: add an interlaced_dct coded var?
748         if (s->picture_structure == PICT_FRAME &&
749             !s->frame_pred_frame_dct)
750             s->interlaced_dct = get_bits1(&s->gb);
751
752         if (IS_QUANT(mb_type))
753             s->qscale = get_qscale(s);
754
755         if (s->concealment_motion_vectors) {
756             /* just parse them */
757             if (s->picture_structure != PICT_FRAME)
758                 skip_bits1(&s->gb);  /* field select */
759
760             s->mv[0][0][0]      =
761             s->last_mv[0][0][0] =
762             s->last_mv[0][1][0] = mpeg_decode_motion(s, s->mpeg_f_code[0][0],
763                                                      s->last_mv[0][0][0]);
764             s->mv[0][0][1]      =
765             s->last_mv[0][0][1] =
766             s->last_mv[0][1][1] = mpeg_decode_motion(s, s->mpeg_f_code[0][1],
767                                                      s->last_mv[0][0][1]);
768
769             check_marker(s->avctx, &s->gb, "after concealment_motion_vectors");
770         } else {
771             /* reset mv prediction */
772             memset(s->last_mv, 0, sizeof(s->last_mv));
773         }
774         s->mb_intra = 1;
775         // if 1, we memcpy blocks in xvmcvideo
776         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
777             ff_xvmc_pack_pblocks(s, -1); // inter are always full blocks
778
779         if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
780             if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
781                 for (i = 0; i < 6; i++)
782                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
783             } else {
784                 for (i = 0; i < mb_block_count; i++)
785                     if ((ret = mpeg2_decode_block_intra(s, *s->pblocks[i], i)) < 0)
786                         return ret;
787             }
788         } else {
789             for (i = 0; i < 6; i++) {
790                 ret = ff_mpeg1_decode_block_intra(&s->gb,
791                                                   s->intra_matrix,
792                                                   s->intra_scantable.permutated,
793                                                   s->last_dc, *s->pblocks[i],
794                                                   i, s->qscale);
795                 if (ret < 0) {
796                     av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n",
797                            s->mb_x, s->mb_y);
798                     return ret;
799                 }
800
801                 s->block_last_index[i] = ret;
802             }
803         }
804     } else {
805         if (mb_type & MB_TYPE_ZERO_MV) {
806             av_assert2(mb_type & MB_TYPE_CBP);
807
808             s->mv_dir = MV_DIR_FORWARD;
809             if (s->picture_structure == PICT_FRAME) {
810                 if (s->picture_structure == PICT_FRAME
811                     && !s->frame_pred_frame_dct)
812                     s->interlaced_dct = get_bits1(&s->gb);
813                 s->mv_type = MV_TYPE_16X16;
814             } else {
815                 s->mv_type            = MV_TYPE_FIELD;
816                 mb_type              |= MB_TYPE_INTERLACED;
817                 s->field_select[0][0] = s->picture_structure - 1;
818             }
819
820             if (IS_QUANT(mb_type))
821                 s->qscale = get_qscale(s);
822
823             s->last_mv[0][0][0] = 0;
824             s->last_mv[0][0][1] = 0;
825             s->last_mv[0][1][0] = 0;
826             s->last_mv[0][1][1] = 0;
827             s->mv[0][0][0]      = 0;
828             s->mv[0][0][1]      = 0;
829         } else {
830             av_assert2(mb_type & MB_TYPE_L0L1);
831             // FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
832             /* get additional motion vector type */
833             if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) {
834                 motion_type = MT_FRAME;
835             } else {
836                 motion_type = get_bits(&s->gb, 2);
837                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
838                     s->interlaced_dct = get_bits1(&s->gb);
839             }
840
841             if (IS_QUANT(mb_type))
842                 s->qscale = get_qscale(s);
843
844             /* motion vectors */
845             s->mv_dir = (mb_type >> 13) & 3;
846             ff_tlog(s->avctx, "motion_type=%d\n", motion_type);
847             switch (motion_type) {
848             case MT_FRAME: /* or MT_16X8 */
849                 if (s->picture_structure == PICT_FRAME) {
850                     mb_type   |= MB_TYPE_16x16;
851                     s->mv_type = MV_TYPE_16X16;
852                     for (i = 0; i < 2; i++) {
853                         if (USES_LIST(mb_type, i)) {
854                             /* MT_FRAME */
855                             s->mv[i][0][0]      =
856                             s->last_mv[i][0][0] =
857                             s->last_mv[i][1][0] =
858                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0],
859                                                    s->last_mv[i][0][0]);
860                             s->mv[i][0][1]      =
861                             s->last_mv[i][0][1] =
862                             s->last_mv[i][1][1] =
863                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1],
864                                                    s->last_mv[i][0][1]);
865                             /* full_pel: only for MPEG-1 */
866                             if (s->full_pel[i]) {
867                                 s->mv[i][0][0] *= 2;
868                                 s->mv[i][0][1] *= 2;
869                             }
870                         }
871                     }
872                 } else {
873                     mb_type   |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
874                     s->mv_type = MV_TYPE_16X8;
875                     for (i = 0; i < 2; i++) {
876                         if (USES_LIST(mb_type, i)) {
877                             /* MT_16X8 */
878                             for (j = 0; j < 2; j++) {
879                                 s->field_select[i][j] = get_bits1(&s->gb);
880                                 for (k = 0; k < 2; k++) {
881                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
882                                                              s->last_mv[i][j][k]);
883                                     s->last_mv[i][j][k] = val;
884                                     s->mv[i][j][k]      = val;
885                                 }
886                             }
887                         }
888                     }
889                 }
890                 break;
891             case MT_FIELD:
892                 s->mv_type = MV_TYPE_FIELD;
893                 if (s->picture_structure == PICT_FRAME) {
894                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
895                     for (i = 0; i < 2; i++) {
896                         if (USES_LIST(mb_type, i)) {
897                             for (j = 0; j < 2; j++) {
898                                 s->field_select[i][j] = get_bits1(&s->gb);
899                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
900                                                          s->last_mv[i][j][0]);
901                                 s->last_mv[i][j][0] = val;
902                                 s->mv[i][j][0]      = val;
903                                 ff_tlog(s->avctx, "fmx=%d\n", val);
904                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
905                                                          s->last_mv[i][j][1] >> 1);
906                                 s->last_mv[i][j][1] = 2 * val;
907                                 s->mv[i][j][1]      = val;
908                                 ff_tlog(s->avctx, "fmy=%d\n", val);
909                             }
910                         }
911                     }
912                 } else {
913                     av_assert0(!s->progressive_sequence);
914                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
915                     for (i = 0; i < 2; i++) {
916                         if (USES_LIST(mb_type, i)) {
917                             s->field_select[i][0] = get_bits1(&s->gb);
918                             for (k = 0; k < 2; k++) {
919                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
920                                                          s->last_mv[i][0][k]);
921                                 s->last_mv[i][0][k] = val;
922                                 s->last_mv[i][1][k] = val;
923                                 s->mv[i][0][k]      = val;
924                             }
925                         }
926                     }
927                 }
928                 break;
929             case MT_DMV:
930                 if (s->progressive_sequence){
931                     av_log(s->avctx, AV_LOG_ERROR, "MT_DMV in progressive_sequence\n");
932                     return AVERROR_INVALIDDATA;
933                 }
934                 s->mv_type = MV_TYPE_DMV;
935                 for (i = 0; i < 2; i++) {
936                     if (USES_LIST(mb_type, i)) {
937                         int dmx, dmy, mx, my, m;
938                         const int my_shift = s->picture_structure == PICT_FRAME;
939
940                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
941                                                 s->last_mv[i][0][0]);
942                         s->last_mv[i][0][0] = mx;
943                         s->last_mv[i][1][0] = mx;
944                         dmx = get_dmv(s);
945                         my  = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
946                                                  s->last_mv[i][0][1] >> my_shift);
947                         dmy = get_dmv(s);
948
949
950                         s->last_mv[i][0][1] = my * (1 << my_shift);
951                         s->last_mv[i][1][1] = my * (1 << my_shift);
952
953                         s->mv[i][0][0] = mx;
954                         s->mv[i][0][1] = my;
955                         s->mv[i][1][0] = mx; // not used
956                         s->mv[i][1][1] = my; // not used
957
958                         if (s->picture_structure == PICT_FRAME) {
959                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
960
961                             // m = 1 + 2 * s->top_field_first;
962                             m = s->top_field_first ? 1 : 3;
963
964                             /* top -> top pred */
965                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
966                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
967                             m = 4 - m;
968                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
969                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
970                         } else {
971                             mb_type |= MB_TYPE_16x16;
972
973                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
974                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
975                             if (s->picture_structure == PICT_TOP_FIELD)
976                                 s->mv[i][2][1]--;
977                             else
978                                 s->mv[i][2][1]++;
979                         }
980                     }
981                 }
982                 break;
983             default:
984                 av_log(s->avctx, AV_LOG_ERROR,
985                        "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
986                 return AVERROR_INVALIDDATA;
987             }
988         }
989
990         s->mb_intra = 0;
991         if (HAS_CBP(mb_type)) {
992             s->bdsp.clear_blocks(s->block[0]);
993
994             cbp = get_vlc2(&s->gb, ff_mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
995             if (mb_block_count > 6) {
996                 cbp *= 1 << mb_block_count - 6;
997                 cbp  |= get_bits(&s->gb, mb_block_count - 6);
998                 s->bdsp.clear_blocks(s->block[6]);
999             }
1000             if (cbp <= 0) {
1001                 av_log(s->avctx, AV_LOG_ERROR,
1002                        "invalid cbp %d at %d %d\n", cbp, s->mb_x, s->mb_y);
1003                 return AVERROR_INVALIDDATA;
1004             }
1005
1006             // if 1, we memcpy blocks in xvmcvideo
1007             if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1008                 ff_xvmc_pack_pblocks(s, cbp);
1009
1010             if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
1011                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1012                     for (i = 0; i < 6; i++) {
1013                         if (cbp & 32)
1014                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
1015                         else
1016                             s->block_last_index[i] = -1;
1017                         cbp += cbp;
1018                     }
1019                 } else {
1020                     cbp <<= 12 - mb_block_count;
1021
1022                     for (i = 0; i < mb_block_count; i++) {
1023                         if (cbp & (1 << 11)) {
1024                             if ((ret = mpeg2_decode_block_non_intra(s, *s->pblocks[i], i)) < 0)
1025                                 return ret;
1026                         } else {
1027                             s->block_last_index[i] = -1;
1028                         }
1029                         cbp += cbp;
1030                     }
1031                 }
1032             } else {
1033                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1034                     for (i = 0; i < 6; i++) {
1035                         if (cbp & 32)
1036                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
1037                         else
1038                             s->block_last_index[i] = -1;
1039                         cbp += cbp;
1040                     }
1041                 } else {
1042                     for (i = 0; i < 6; i++) {
1043                         if (cbp & 32) {
1044                             if ((ret = mpeg1_decode_block_inter(s, *s->pblocks[i], i)) < 0)
1045                                 return ret;
1046                         } else {
1047                             s->block_last_index[i] = -1;
1048                         }
1049                         cbp += cbp;
1050                     }
1051                 }
1052             }
1053         } else {
1054             for (i = 0; i < 12; i++)
1055                 s->block_last_index[i] = -1;
1056         }
1057     }
1058
1059     s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] = mb_type;
1060
1061     return 0;
1062 }
1063
1064 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1065 {
1066     Mpeg1Context *s    = avctx->priv_data;
1067     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1068
1069     ff_mpv_decode_defaults(s2);
1070
1071     if (   avctx->codec_tag != AV_RL32("VCR2")
1072         && avctx->codec_tag != AV_RL32("BW10"))
1073         avctx->coded_width = avctx->coded_height = 0; // do not trust dimensions from input
1074     ff_mpv_decode_init(s2, avctx);
1075
1076     s->mpeg_enc_ctx.avctx  = avctx;
1077
1078     /* we need some permutation to store matrices,
1079      * until the decoder sets the real permutation. */
1080     ff_mpv_idct_init(s2);
1081     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1082     ff_mpeg12_init_vlcs();
1083
1084     s2->chroma_format              = 1;
1085     s->mpeg_enc_ctx_allocated      = 0;
1086     s->mpeg_enc_ctx.picture_number = 0;
1087     s->repeat_field                = 0;
1088     s->mpeg_enc_ctx.codec_id       = avctx->codec->id;
1089     avctx->color_range             = AVCOL_RANGE_MPEG;
1090     return 0;
1091 }
1092
1093 #if HAVE_THREADS
1094 static int mpeg_decode_update_thread_context(AVCodecContext *avctx,
1095                                              const AVCodecContext *avctx_from)
1096 {
1097     Mpeg1Context *ctx = avctx->priv_data, *ctx_from = avctx_from->priv_data;
1098     MpegEncContext *s = &ctx->mpeg_enc_ctx, *s1 = &ctx_from->mpeg_enc_ctx;
1099     int err;
1100
1101     if (avctx == avctx_from               ||
1102         !ctx_from->mpeg_enc_ctx_allocated ||
1103         !s1->context_initialized)
1104         return 0;
1105
1106     err = ff_mpeg_update_thread_context(avctx, avctx_from);
1107     if (err)
1108         return err;
1109
1110     if (!ctx->mpeg_enc_ctx_allocated)
1111         memcpy(s + 1, s1 + 1, sizeof(Mpeg1Context) - sizeof(MpegEncContext));
1112
1113     if (!(s->pict_type == AV_PICTURE_TYPE_B || s->low_delay))
1114         s->picture_number++;
1115
1116     return 0;
1117 }
1118 #endif
1119
1120 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1121                                  const uint8_t *new_perm)
1122 {
1123     uint16_t temp_matrix[64];
1124     int i;
1125
1126     memcpy(temp_matrix, matrix, 64 * sizeof(uint16_t));
1127
1128     for (i = 0; i < 64; i++)
1129         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1130 }
1131
1132 static const enum AVPixelFormat mpeg1_hwaccel_pixfmt_list_420[] = {
1133 #if CONFIG_MPEG1_XVMC_HWACCEL
1134     AV_PIX_FMT_XVMC,
1135 #endif
1136 #if CONFIG_MPEG1_VDPAU_HWACCEL
1137     AV_PIX_FMT_VDPAU,
1138 #endif
1139     AV_PIX_FMT_YUV420P,
1140     AV_PIX_FMT_NONE
1141 };
1142
1143 static const enum AVPixelFormat mpeg2_hwaccel_pixfmt_list_420[] = {
1144 #if CONFIG_MPEG2_XVMC_HWACCEL
1145     AV_PIX_FMT_XVMC,
1146 #endif
1147 #if CONFIG_MPEG2_VDPAU_HWACCEL
1148     AV_PIX_FMT_VDPAU,
1149 #endif
1150 #if CONFIG_MPEG2_DXVA2_HWACCEL
1151     AV_PIX_FMT_DXVA2_VLD,
1152 #endif
1153 #if CONFIG_MPEG2_D3D11VA_HWACCEL
1154     AV_PIX_FMT_D3D11VA_VLD,
1155     AV_PIX_FMT_D3D11,
1156 #endif
1157 #if CONFIG_MPEG2_VAAPI_HWACCEL
1158     AV_PIX_FMT_VAAPI,
1159 #endif
1160 #if CONFIG_MPEG2_VIDEOTOOLBOX_HWACCEL
1161     AV_PIX_FMT_VIDEOTOOLBOX,
1162 #endif
1163     AV_PIX_FMT_YUV420P,
1164     AV_PIX_FMT_NONE
1165 };
1166
1167 static const enum AVPixelFormat mpeg12_pixfmt_list_422[] = {
1168     AV_PIX_FMT_YUV422P,
1169     AV_PIX_FMT_NONE
1170 };
1171
1172 static const enum AVPixelFormat mpeg12_pixfmt_list_444[] = {
1173     AV_PIX_FMT_YUV444P,
1174     AV_PIX_FMT_NONE
1175 };
1176
1177 static enum AVPixelFormat mpeg_get_pixelformat(AVCodecContext *avctx)
1178 {
1179     Mpeg1Context *s1  = avctx->priv_data;
1180     MpegEncContext *s = &s1->mpeg_enc_ctx;
1181     const enum AVPixelFormat *pix_fmts;
1182
1183     if (CONFIG_GRAY && (avctx->flags & AV_CODEC_FLAG_GRAY))
1184         return AV_PIX_FMT_GRAY8;
1185
1186     if (s->chroma_format < 2)
1187         pix_fmts = avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO ?
1188                                 mpeg1_hwaccel_pixfmt_list_420 :
1189                                 mpeg2_hwaccel_pixfmt_list_420;
1190     else if (s->chroma_format == 2)
1191         pix_fmts = mpeg12_pixfmt_list_422;
1192     else
1193         pix_fmts = mpeg12_pixfmt_list_444;
1194
1195     return ff_thread_get_format(avctx, pix_fmts);
1196 }
1197
1198 static void setup_hwaccel_for_pixfmt(AVCodecContext *avctx)
1199 {
1200     // until then pix_fmt may be changed right after codec init
1201     if (avctx->hwaccel)
1202         if (avctx->idct_algo == FF_IDCT_AUTO)
1203             avctx->idct_algo = FF_IDCT_NONE;
1204
1205     if (avctx->hwaccel && avctx->pix_fmt == AV_PIX_FMT_XVMC) {
1206         Mpeg1Context *s1 = avctx->priv_data;
1207         MpegEncContext *s = &s1->mpeg_enc_ctx;
1208
1209         s->pack_pblocks = 1;
1210     }
1211 }
1212
1213 /* Call this function when we know all parameters.
1214  * It may be called in different places for MPEG-1 and MPEG-2. */
1215 static int mpeg_decode_postinit(AVCodecContext *avctx)
1216 {
1217     Mpeg1Context *s1  = avctx->priv_data;
1218     MpegEncContext *s = &s1->mpeg_enc_ctx;
1219     uint8_t old_permutation[64];
1220     int ret;
1221
1222     if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1223         // MPEG-1 aspect
1224         AVRational aspect_inv = av_d2q(ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1225         avctx->sample_aspect_ratio = (AVRational) { aspect_inv.den, aspect_inv.num };
1226     } else { // MPEG-2
1227         // MPEG-2 aspect
1228         if (s->aspect_ratio_info > 1) {
1229             AVRational dar =
1230                 av_mul_q(av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1231                                   (AVRational) { s1->pan_scan.width,
1232                                                  s1->pan_scan.height }),
1233                          (AVRational) { s->width, s->height });
1234
1235             /* We ignore the spec here and guess a bit as reality does not
1236              * match the spec, see for example res_change_ffmpeg_aspect.ts
1237              * and sequence-display-aspect.mpg.
1238              * issue1613, 621, 562 */
1239             if ((s1->pan_scan.width == 0) || (s1->pan_scan.height == 0) ||
1240                 (av_cmp_q(dar, (AVRational) { 4, 3 }) &&
1241                  av_cmp_q(dar, (AVRational) { 16, 9 }))) {
1242                 s->avctx->sample_aspect_ratio =
1243                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1244                              (AVRational) { s->width, s->height });
1245             } else {
1246                 s->avctx->sample_aspect_ratio =
1247                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1248                              (AVRational) { s1->pan_scan.width, s1->pan_scan.height });
1249 // issue1613 4/3 16/9 -> 16/9
1250 // res_change_ffmpeg_aspect.ts 4/3 225/44 ->4/3
1251 // widescreen-issue562.mpg 4/3 16/9 -> 16/9
1252 //                s->avctx->sample_aspect_ratio = av_mul_q(s->avctx->sample_aspect_ratio, (AVRational) {s->width, s->height});
1253                 ff_dlog(avctx, "aspect A %d/%d\n",
1254                         ff_mpeg2_aspect[s->aspect_ratio_info].num,
1255                         ff_mpeg2_aspect[s->aspect_ratio_info].den);
1256                 ff_dlog(avctx, "aspect B %d/%d\n", s->avctx->sample_aspect_ratio.num,
1257                         s->avctx->sample_aspect_ratio.den);
1258             }
1259         } else {
1260             s->avctx->sample_aspect_ratio =
1261                 ff_mpeg2_aspect[s->aspect_ratio_info];
1262         }
1263     } // MPEG-2
1264
1265     if (av_image_check_sar(s->width, s->height,
1266                            avctx->sample_aspect_ratio) < 0) {
1267         av_log(avctx, AV_LOG_WARNING, "ignoring invalid SAR: %u/%u\n",
1268                 avctx->sample_aspect_ratio.num,
1269                 avctx->sample_aspect_ratio.den);
1270         avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
1271     }
1272
1273     if ((s1->mpeg_enc_ctx_allocated == 0)                   ||
1274         avctx->coded_width       != s->width                ||
1275         avctx->coded_height      != s->height               ||
1276         s1->save_width           != s->width                ||
1277         s1->save_height          != s->height               ||
1278         av_cmp_q(s1->save_aspect, s->avctx->sample_aspect_ratio) ||
1279         (s1->save_progressive_seq != s->progressive_sequence && FFALIGN(s->height, 16) != FFALIGN(s->height, 32)) ||
1280         0) {
1281         if (s1->mpeg_enc_ctx_allocated) {
1282             ParseContext pc = s->parse_context;
1283             s->parse_context.buffer = 0;
1284             ff_mpv_common_end(s);
1285             s->parse_context = pc;
1286             s1->mpeg_enc_ctx_allocated = 0;
1287         }
1288
1289         ret = ff_set_dimensions(avctx, s->width, s->height);
1290         if (ret < 0)
1291             return ret;
1292
1293         if (avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO && s->bit_rate) {
1294             avctx->rc_max_rate = s->bit_rate;
1295         } else if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO && s->bit_rate &&
1296                    (s->bit_rate != 0x3FFFF*400 || s->vbv_delay != 0xFFFF)) {
1297             avctx->bit_rate = s->bit_rate;
1298         }
1299         s1->save_aspect          = s->avctx->sample_aspect_ratio;
1300         s1->save_width           = s->width;
1301         s1->save_height          = s->height;
1302         s1->save_progressive_seq = s->progressive_sequence;
1303
1304         /* low_delay may be forced, in this case we will have B-frames
1305          * that behave like P-frames. */
1306         avctx->has_b_frames = !s->low_delay;
1307
1308         if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1309             // MPEG-1 fps
1310             avctx->framerate = ff_mpeg12_frame_rate_tab[s->frame_rate_index];
1311             avctx->ticks_per_frame     = 1;
1312
1313             avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1314         } else { // MPEG-2
1315             // MPEG-2 fps
1316             av_reduce(&s->avctx->framerate.num,
1317                       &s->avctx->framerate.den,
1318                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1319                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1320                       1 << 30);
1321             avctx->ticks_per_frame = 2;
1322
1323             switch (s->chroma_format) {
1324             case 1: avctx->chroma_sample_location = AVCHROMA_LOC_LEFT; break;
1325             case 2:
1326             case 3: avctx->chroma_sample_location = AVCHROMA_LOC_TOPLEFT; break;
1327             default: av_assert0(0);
1328             }
1329         } // MPEG-2
1330
1331         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1332         setup_hwaccel_for_pixfmt(avctx);
1333
1334         /* Quantization matrices may need reordering
1335          * if DCT permutation is changed. */
1336         memcpy(old_permutation, s->idsp.idct_permutation, 64 * sizeof(uint8_t));
1337
1338         ff_mpv_idct_init(s);
1339         if ((ret = ff_mpv_common_init(s)) < 0)
1340             return ret;
1341
1342         quant_matrix_rebuild(s->intra_matrix,        old_permutation, s->idsp.idct_permutation);
1343         quant_matrix_rebuild(s->inter_matrix,        old_permutation, s->idsp.idct_permutation);
1344         quant_matrix_rebuild(s->chroma_intra_matrix, old_permutation, s->idsp.idct_permutation);
1345         quant_matrix_rebuild(s->chroma_inter_matrix, old_permutation, s->idsp.idct_permutation);
1346
1347         s1->mpeg_enc_ctx_allocated = 1;
1348     }
1349     return 0;
1350 }
1351
1352 static int mpeg1_decode_picture(AVCodecContext *avctx, const uint8_t *buf,
1353                                 int buf_size)
1354 {
1355     Mpeg1Context *s1  = avctx->priv_data;
1356     MpegEncContext *s = &s1->mpeg_enc_ctx;
1357     int ref, f_code, vbv_delay;
1358
1359     init_get_bits(&s->gb, buf, buf_size * 8);
1360
1361     ref = get_bits(&s->gb, 10); /* temporal ref */
1362     s->pict_type = get_bits(&s->gb, 3);
1363     if (s->pict_type == 0 || s->pict_type > 3)
1364         return AVERROR_INVALIDDATA;
1365
1366     vbv_delay = get_bits(&s->gb, 16);
1367     s->vbv_delay = vbv_delay;
1368     if (s->pict_type == AV_PICTURE_TYPE_P ||
1369         s->pict_type == AV_PICTURE_TYPE_B) {
1370         s->full_pel[0] = get_bits1(&s->gb);
1371         f_code = get_bits(&s->gb, 3);
1372         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1373             return AVERROR_INVALIDDATA;
1374         f_code += !f_code;
1375         s->mpeg_f_code[0][0] = f_code;
1376         s->mpeg_f_code[0][1] = f_code;
1377     }
1378     if (s->pict_type == AV_PICTURE_TYPE_B) {
1379         s->full_pel[1] = get_bits1(&s->gb);
1380         f_code = get_bits(&s->gb, 3);
1381         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1382             return AVERROR_INVALIDDATA;
1383         f_code += !f_code;
1384         s->mpeg_f_code[1][0] = f_code;
1385         s->mpeg_f_code[1][1] = f_code;
1386     }
1387     s->current_picture.f->pict_type = s->pict_type;
1388     s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1389
1390     if (avctx->debug & FF_DEBUG_PICT_INFO)
1391         av_log(avctx, AV_LOG_DEBUG,
1392                "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1393
1394     s->y_dc_scale = 8;
1395     s->c_dc_scale = 8;
1396     return 0;
1397 }
1398
1399 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1400 {
1401     MpegEncContext *s = &s1->mpeg_enc_ctx;
1402     int horiz_size_ext, vert_size_ext;
1403     int bit_rate_ext;
1404
1405     skip_bits(&s->gb, 1); /* profile and level esc*/
1406     s->avctx->profile       = get_bits(&s->gb, 3);
1407     s->avctx->level         = get_bits(&s->gb, 4);
1408     s->progressive_sequence = get_bits1(&s->gb);   /* progressive_sequence */
1409     s->chroma_format        = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1410
1411     if (!s->chroma_format) {
1412         s->chroma_format = 1;
1413         av_log(s->avctx, AV_LOG_WARNING, "Chroma format invalid\n");
1414     }
1415
1416     horiz_size_ext          = get_bits(&s->gb, 2);
1417     vert_size_ext           = get_bits(&s->gb, 2);
1418     s->width  |= (horiz_size_ext << 12);
1419     s->height |= (vert_size_ext  << 12);
1420     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1421     s->bit_rate += (bit_rate_ext << 18) * 400LL;
1422     check_marker(s->avctx, &s->gb, "after bit rate extension");
1423     s->avctx->rc_buffer_size += get_bits(&s->gb, 8) * 1024 * 16 << 10;
1424
1425     s->low_delay = get_bits1(&s->gb);
1426     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
1427         s->low_delay = 1;
1428
1429     s1->frame_rate_ext.num = get_bits(&s->gb, 2) + 1;
1430     s1->frame_rate_ext.den = get_bits(&s->gb, 5) + 1;
1431
1432     ff_dlog(s->avctx, "sequence extension\n");
1433     s->codec_id = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
1434
1435     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1436         av_log(s->avctx, AV_LOG_DEBUG,
1437                "profile: %d, level: %d ps: %d cf:%d vbv buffer: %d, bitrate:%"PRId64"\n",
1438                s->avctx->profile, s->avctx->level, s->progressive_sequence, s->chroma_format,
1439                s->avctx->rc_buffer_size, s->bit_rate);
1440 }
1441
1442 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1443 {
1444     MpegEncContext *s = &s1->mpeg_enc_ctx;
1445     int color_description, w, h;
1446
1447     skip_bits(&s->gb, 3); /* video format */
1448     color_description = get_bits1(&s->gb);
1449     if (color_description) {
1450         s->avctx->color_primaries = get_bits(&s->gb, 8);
1451         s->avctx->color_trc       = get_bits(&s->gb, 8);
1452         s->avctx->colorspace      = get_bits(&s->gb, 8);
1453     }
1454     w = get_bits(&s->gb, 14);
1455     skip_bits(&s->gb, 1); // marker
1456     h = get_bits(&s->gb, 14);
1457     // remaining 3 bits are zero padding
1458
1459     s1->pan_scan.width  = 16 * w;
1460     s1->pan_scan.height = 16 * h;
1461
1462     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1463         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1464 }
1465
1466 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1467 {
1468     MpegEncContext *s = &s1->mpeg_enc_ctx;
1469     int i, nofco;
1470
1471     nofco = 1;
1472     if (s->progressive_sequence) {
1473         if (s->repeat_first_field) {
1474             nofco++;
1475             if (s->top_field_first)
1476                 nofco++;
1477         }
1478     } else {
1479         if (s->picture_structure == PICT_FRAME) {
1480             nofco++;
1481             if (s->repeat_first_field)
1482                 nofco++;
1483         }
1484     }
1485     for (i = 0; i < nofco; i++) {
1486         s1->pan_scan.position[i][0] = get_sbits(&s->gb, 16);
1487         skip_bits(&s->gb, 1); // marker
1488         s1->pan_scan.position[i][1] = get_sbits(&s->gb, 16);
1489         skip_bits(&s->gb, 1); // marker
1490     }
1491
1492     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1493         av_log(s->avctx, AV_LOG_DEBUG,
1494                "pde (%"PRId16",%"PRId16") (%"PRId16",%"PRId16") (%"PRId16",%"PRId16")\n",
1495                s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1496                s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1497                s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]);
1498 }
1499
1500 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64],
1501                        uint16_t matrix1[64], int intra)
1502 {
1503     int i;
1504
1505     for (i = 0; i < 64; i++) {
1506         int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1507         int v = get_bits(&s->gb, 8);
1508         if (v == 0) {
1509             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1510             return AVERROR_INVALIDDATA;
1511         }
1512         if (intra && i == 0 && v != 8) {
1513             av_log(s->avctx, AV_LOG_DEBUG, "intra matrix specifies invalid DC quantizer %d, ignoring\n", v);
1514             v = 8; // needed by pink.mpg / issue1046
1515         }
1516         matrix0[j] = v;
1517         if (matrix1)
1518             matrix1[j] = v;
1519     }
1520     return 0;
1521 }
1522
1523 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1524 {
1525     ff_dlog(s->avctx, "matrix extension\n");
1526
1527     if (get_bits1(&s->gb))
1528         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1529     if (get_bits1(&s->gb))
1530         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1531     if (get_bits1(&s->gb))
1532         load_matrix(s, s->chroma_intra_matrix, NULL, 1);
1533     if (get_bits1(&s->gb))
1534         load_matrix(s, s->chroma_inter_matrix, NULL, 0);
1535 }
1536
1537 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1538 {
1539     MpegEncContext *s = &s1->mpeg_enc_ctx;
1540
1541     s->full_pel[0]       = s->full_pel[1] = 0;
1542     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1543     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1544     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1545     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1546     if (!s->pict_type && s1->mpeg_enc_ctx_allocated) {
1547         av_log(s->avctx, AV_LOG_ERROR,
1548                "Missing picture start code, guessing missing values\n");
1549         if (s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1] == 15) {
1550             if (s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1551                 s->pict_type = AV_PICTURE_TYPE_I;
1552             else
1553                 s->pict_type = AV_PICTURE_TYPE_P;
1554         } else
1555             s->pict_type = AV_PICTURE_TYPE_B;
1556         s->current_picture.f->pict_type = s->pict_type;
1557         s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1558     }
1559     s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0];
1560     s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1];
1561     s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0];
1562     s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1];
1563
1564     s->intra_dc_precision         = get_bits(&s->gb, 2);
1565     s->picture_structure          = get_bits(&s->gb, 2);
1566     s->top_field_first            = get_bits1(&s->gb);
1567     s->frame_pred_frame_dct       = get_bits1(&s->gb);
1568     s->concealment_motion_vectors = get_bits1(&s->gb);
1569     s->q_scale_type               = get_bits1(&s->gb);
1570     s->intra_vlc_format           = get_bits1(&s->gb);
1571     s->alternate_scan             = get_bits1(&s->gb);
1572     s->repeat_first_field         = get_bits1(&s->gb);
1573     s->chroma_420_type            = get_bits1(&s->gb);
1574     s->progressive_frame          = get_bits1(&s->gb);
1575
1576     if (s->alternate_scan) {
1577         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
1578         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
1579     } else {
1580         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
1581         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
1582     }
1583
1584     /* composite display not parsed */
1585     ff_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1586     ff_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
1587     ff_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
1588     ff_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1589     ff_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1590     ff_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1591     ff_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1592     ff_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1593     ff_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1594 }
1595
1596 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size)
1597 {
1598     AVCodecContext *avctx = s->avctx;
1599     Mpeg1Context *s1      = (Mpeg1Context *) s;
1600     int ret;
1601
1602     /* start frame decoding */
1603     if (s->first_field || s->picture_structure == PICT_FRAME) {
1604         AVFrameSideData *pan_scan;
1605
1606         if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
1607             return ret;
1608
1609         ff_mpeg_er_frame_start(s);
1610
1611         /* first check if we must repeat the frame */
1612         s->current_picture_ptr->f->repeat_pict = 0;
1613         if (s->repeat_first_field) {
1614             if (s->progressive_sequence) {
1615                 if (s->top_field_first)
1616                     s->current_picture_ptr->f->repeat_pict = 4;
1617                 else
1618                     s->current_picture_ptr->f->repeat_pict = 2;
1619             } else if (s->progressive_frame) {
1620                 s->current_picture_ptr->f->repeat_pict = 1;
1621             }
1622         }
1623
1624         pan_scan = av_frame_new_side_data(s->current_picture_ptr->f,
1625                                           AV_FRAME_DATA_PANSCAN,
1626                                           sizeof(s1->pan_scan));
1627         if (!pan_scan)
1628             return AVERROR(ENOMEM);
1629         memcpy(pan_scan->data, &s1->pan_scan, sizeof(s1->pan_scan));
1630
1631         if (s1->a53_caption) {
1632             AVFrameSideData *sd = av_frame_new_side_data(
1633                 s->current_picture_ptr->f, AV_FRAME_DATA_A53_CC,
1634                 s1->a53_caption_size);
1635             if (sd)
1636                 memcpy(sd->data, s1->a53_caption, s1->a53_caption_size);
1637             av_freep(&s1->a53_caption);
1638         }
1639
1640         if (s1->has_stereo3d) {
1641             AVStereo3D *stereo = av_stereo3d_create_side_data(s->current_picture_ptr->f);
1642             if (!stereo)
1643                 return AVERROR(ENOMEM);
1644
1645             *stereo = s1->stereo3d;
1646             s1->has_stereo3d = 0;
1647         }
1648
1649         if (s1->has_afd) {
1650             AVFrameSideData *sd =
1651                 av_frame_new_side_data(s->current_picture_ptr->f,
1652                                        AV_FRAME_DATA_AFD, 1);
1653             if (!sd)
1654                 return AVERROR(ENOMEM);
1655
1656             *sd->data   = s1->afd;
1657             s1->has_afd = 0;
1658         }
1659
1660         if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_FRAME))
1661             ff_thread_finish_setup(avctx);
1662     } else { // second field
1663         int i;
1664
1665         if (!s->current_picture_ptr) {
1666             av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1667             return AVERROR_INVALIDDATA;
1668         }
1669
1670         if (s->avctx->hwaccel &&
1671             (s->avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
1672             if ((ret = s->avctx->hwaccel->end_frame(s->avctx)) < 0) {
1673                 av_log(avctx, AV_LOG_ERROR,
1674                        "hardware accelerator failed to decode first field\n");
1675                 return ret;
1676             }
1677         }
1678
1679         for (i = 0; i < 4; i++) {
1680             s->current_picture.f->data[i] = s->current_picture_ptr->f->data[i];
1681             if (s->picture_structure == PICT_BOTTOM_FIELD)
1682                 s->current_picture.f->data[i] +=
1683                     s->current_picture_ptr->f->linesize[i];
1684         }
1685     }
1686
1687     if (avctx->hwaccel) {
1688         if ((ret = avctx->hwaccel->start_frame(avctx, buf, buf_size)) < 0)
1689             return ret;
1690     }
1691
1692     return 0;
1693 }
1694
1695 #define DECODE_SLICE_ERROR -1
1696 #define DECODE_SLICE_OK     0
1697
1698 /**
1699  * Decode a slice.
1700  * MpegEncContext.mb_y must be set to the MB row from the startcode.
1701  * @return DECODE_SLICE_ERROR if the slice is damaged,
1702  *         DECODE_SLICE_OK if this slice is OK
1703  */
1704 static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
1705                              const uint8_t **buf, int buf_size)
1706 {
1707     AVCodecContext *avctx = s->avctx;
1708     const int lowres      = s->avctx->lowres;
1709     const int field_pic   = s->picture_structure != PICT_FRAME;
1710     int ret;
1711
1712     s->resync_mb_x =
1713     s->resync_mb_y = -1;
1714
1715     av_assert0(mb_y < s->mb_height);
1716
1717     init_get_bits(&s->gb, *buf, buf_size * 8);
1718     if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
1719         skip_bits(&s->gb, 3);
1720
1721     ff_mpeg1_clean_buffers(s);
1722     s->interlaced_dct = 0;
1723
1724     s->qscale = get_qscale(s);
1725
1726     if (s->qscale == 0) {
1727         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1728         return AVERROR_INVALIDDATA;
1729     }
1730
1731     /* extra slice info */
1732     if (skip_1stop_8data_bits(&s->gb) < 0)
1733         return AVERROR_INVALIDDATA;
1734
1735     s->mb_x = 0;
1736
1737     if (mb_y == 0 && s->codec_tag == AV_RL32("SLIF")) {
1738         skip_bits1(&s->gb);
1739     } else {
1740         while (get_bits_left(&s->gb) > 0) {
1741             int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1742                                 MBINCR_VLC_BITS, 2);
1743             if (code < 0) {
1744                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1745                 return AVERROR_INVALIDDATA;
1746             }
1747             if (code >= 33) {
1748                 if (code == 33)
1749                     s->mb_x += 33;
1750                 /* otherwise, stuffing, nothing to do */
1751             } else {
1752                 s->mb_x += code;
1753                 break;
1754             }
1755         }
1756     }
1757
1758     if (s->mb_x >= (unsigned) s->mb_width) {
1759         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1760         return AVERROR_INVALIDDATA;
1761     }
1762
1763     if (avctx->hwaccel && avctx->hwaccel->decode_slice) {
1764         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1765         int start_code = -1;
1766         buf_end = avpriv_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1767         if (buf_end < *buf + buf_size)
1768             buf_end -= 4;
1769         s->mb_y = mb_y;
1770         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1771             return DECODE_SLICE_ERROR;
1772         *buf = buf_end;
1773         return DECODE_SLICE_OK;
1774     }
1775
1776     s->resync_mb_x = s->mb_x;
1777     s->resync_mb_y = s->mb_y = mb_y;
1778     s->mb_skip_run = 0;
1779     ff_init_block_index(s);
1780
1781     if (s->mb_y == 0 && s->mb_x == 0 && (s->first_field || s->picture_structure == PICT_FRAME)) {
1782         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
1783             av_log(s->avctx, AV_LOG_DEBUG,
1784                    "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",
1785                    s->qscale,
1786                    s->mpeg_f_code[0][0], s->mpeg_f_code[0][1],
1787                    s->mpeg_f_code[1][0], s->mpeg_f_code[1][1],
1788                    s->pict_type  == AV_PICTURE_TYPE_I ? "I" :
1789                    (s->pict_type == AV_PICTURE_TYPE_P ? "P" :
1790                    (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
1791                    s->progressive_sequence ? "ps"  : "",
1792                    s->progressive_frame    ? "pf"  : "",
1793                    s->alternate_scan       ? "alt" : "",
1794                    s->top_field_first      ? "top" : "",
1795                    s->intra_dc_precision, s->picture_structure,
1796                    s->frame_pred_frame_dct, s->concealment_motion_vectors,
1797                    s->q_scale_type, s->intra_vlc_format,
1798                    s->repeat_first_field, s->chroma_420_type ? "420" : "");
1799         }
1800     }
1801
1802     for (;;) {
1803         // If 1, we memcpy blocks in xvmcvideo.
1804         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1805             ff_xvmc_init_block(s); // set s->block
1806
1807         if ((ret = mpeg_decode_mb(s, s->block)) < 0)
1808             return ret;
1809
1810         // Note motion_val is normally NULL unless we want to extract the MVs.
1811         if (s->current_picture.motion_val[0] && !s->encoding) {
1812             const int wrap = s->b8_stride;
1813             int xy         = s->mb_x * 2 + s->mb_y * 2 * wrap;
1814             int b8_xy      = 4 * (s->mb_x + s->mb_y * s->mb_stride);
1815             int motion_x, motion_y, dir, i;
1816
1817             for (i = 0; i < 2; i++) {
1818                 for (dir = 0; dir < 2; dir++) {
1819                     if (s->mb_intra ||
1820                         (dir == 1 && s->pict_type != AV_PICTURE_TYPE_B)) {
1821                         motion_x = motion_y = 0;
1822                     } else if (s->mv_type == MV_TYPE_16X16 ||
1823                                (s->mv_type == MV_TYPE_FIELD && field_pic)) {
1824                         motion_x = s->mv[dir][0][0];
1825                         motion_y = s->mv[dir][0][1];
1826                     } else { /* if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8)) */
1827                         motion_x = s->mv[dir][i][0];
1828                         motion_y = s->mv[dir][i][1];
1829                     }
1830
1831                     s->current_picture.motion_val[dir][xy][0]     = motion_x;
1832                     s->current_picture.motion_val[dir][xy][1]     = motion_y;
1833                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1834                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1835                     s->current_picture.ref_index [dir][b8_xy]     =
1836                     s->current_picture.ref_index [dir][b8_xy + 1] = s->field_select[dir][i];
1837                     av_assert2(s->field_select[dir][i] == 0 ||
1838                                s->field_select[dir][i] == 1);
1839                 }
1840                 xy    += wrap;
1841                 b8_xy += 2;
1842             }
1843         }
1844
1845         s->dest[0] += 16 >> lowres;
1846         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1847         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1848
1849         ff_mpv_reconstruct_mb(s, s->block);
1850
1851         if (++s->mb_x >= s->mb_width) {
1852             const int mb_size = 16 >> s->avctx->lowres;
1853             int left;
1854
1855             ff_mpeg_draw_horiz_band(s, mb_size * (s->mb_y >> field_pic), mb_size);
1856             ff_mpv_report_decode_progress(s);
1857
1858             s->mb_x  = 0;
1859             s->mb_y += 1 << field_pic;
1860
1861             if (s->mb_y >= s->mb_height) {
1862                 int left   = get_bits_left(&s->gb);
1863                 int is_d10 = s->chroma_format == 2 &&
1864                              s->pict_type == AV_PICTURE_TYPE_I &&
1865                              avctx->profile == 0 && avctx->level == 5 &&
1866                              s->intra_dc_precision == 2 &&
1867                              s->q_scale_type == 1 && s->alternate_scan == 0 &&
1868                              s->progressive_frame == 0
1869                              /* vbv_delay == 0xBBB || 0xE10 */;
1870
1871                 if (left >= 32 && !is_d10) {
1872                     GetBitContext gb = s->gb;
1873                     align_get_bits(&gb);
1874                     if (show_bits(&gb, 24) == 0x060E2B) {
1875                         av_log(avctx, AV_LOG_DEBUG, "Invalid MXF data found in video stream\n");
1876                         is_d10 = 1;
1877                     }
1878                     if (left > 32 && show_bits_long(&gb, 32) == 0x201) {
1879                         av_log(avctx, AV_LOG_DEBUG, "skipping m704 alpha (unsupported)\n");
1880                         goto eos;
1881                     }
1882                 }
1883
1884                 if (left < 0 ||
1885                     (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10) ||
1886                     ((avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE)) && left > 8)) {
1887                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X at %d %d\n",
1888                            left, left>0 ? show_bits(&s->gb, FFMIN(left, 23)) : 0, s->mb_x, s->mb_y);
1889                     return AVERROR_INVALIDDATA;
1890                 } else
1891                     goto eos;
1892             }
1893             // There are some files out there which are missing the last slice
1894             // in cases where the slice is completely outside the visible
1895             // area, we detect this here instead of running into the end expecting
1896             // more data
1897             left = get_bits_left(&s->gb);
1898             if (s->mb_y >= ((s->height + 15) >> 4) &&
1899                 !s->progressive_sequence &&
1900                 left <= 25 &&
1901                 left >= 0 &&
1902                 s->mb_skip_run == -1 &&
1903                 (!left || show_bits(&s->gb, left) == 0))
1904                 goto eos;
1905
1906             ff_init_block_index(s);
1907         }
1908
1909         /* skip mb handling */
1910         if (s->mb_skip_run == -1) {
1911             /* read increment again */
1912             s->mb_skip_run = 0;
1913             for (;;) {
1914                 int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1915                                     MBINCR_VLC_BITS, 2);
1916                 if (code < 0) {
1917                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1918                     return AVERROR_INVALIDDATA;
1919                 }
1920                 if (code >= 33) {
1921                     if (code == 33) {
1922                         s->mb_skip_run += 33;
1923                     } else if (code == 35) {
1924                         if (s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0) {
1925                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1926                             return AVERROR_INVALIDDATA;
1927                         }
1928                         goto eos; /* end of slice */
1929                     }
1930                     /* otherwise, stuffing, nothing to do */
1931                 } else {
1932                     s->mb_skip_run += code;
1933                     break;
1934                 }
1935             }
1936             if (s->mb_skip_run) {
1937                 int i;
1938                 if (s->pict_type == AV_PICTURE_TYPE_I) {
1939                     av_log(s->avctx, AV_LOG_ERROR,
1940                            "skipped MB in I-frame at %d %d\n", s->mb_x, s->mb_y);
1941                     return AVERROR_INVALIDDATA;
1942                 }
1943
1944                 /* skip mb */
1945                 s->mb_intra = 0;
1946                 for (i = 0; i < 12; i++)
1947                     s->block_last_index[i] = -1;
1948                 if (s->picture_structure == PICT_FRAME)
1949                     s->mv_type = MV_TYPE_16X16;
1950                 else
1951                     s->mv_type = MV_TYPE_FIELD;
1952                 if (s->pict_type == AV_PICTURE_TYPE_P) {
1953                     /* if P type, zero motion vector is implied */
1954                     s->mv_dir             = MV_DIR_FORWARD;
1955                     s->mv[0][0][0]        = s->mv[0][0][1]      = 0;
1956                     s->last_mv[0][0][0]   = s->last_mv[0][0][1] = 0;
1957                     s->last_mv[0][1][0]   = s->last_mv[0][1][1] = 0;
1958                     s->field_select[0][0] = (s->picture_structure - 1) & 1;
1959                 } else {
1960                     /* if B type, reuse previous vectors and directions */
1961                     s->mv[0][0][0] = s->last_mv[0][0][0];
1962                     s->mv[0][0][1] = s->last_mv[0][0][1];
1963                     s->mv[1][0][0] = s->last_mv[1][0][0];
1964                     s->mv[1][0][1] = s->last_mv[1][0][1];
1965                 }
1966             }
1967         }
1968     }
1969 eos: // end of slice
1970     if (get_bits_left(&s->gb) < 0) {
1971         av_log(s, AV_LOG_ERROR, "overread %d\n", -get_bits_left(&s->gb));
1972         return AVERROR_INVALIDDATA;
1973     }
1974     *buf += (get_bits_count(&s->gb) - 1) / 8;
1975     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);
1976     return 0;
1977 }
1978
1979 static int slice_decode_thread(AVCodecContext *c, void *arg)
1980 {
1981     MpegEncContext *s   = *(void **) arg;
1982     const uint8_t *buf  = s->gb.buffer;
1983     int mb_y            = s->start_mb_y;
1984     const int field_pic = s->picture_structure != PICT_FRAME;
1985
1986     s->er.error_count = (3 * (s->end_mb_y - s->start_mb_y) * s->mb_width) >> field_pic;
1987
1988     for (;;) {
1989         uint32_t start_code;
1990         int ret;
1991
1992         ret = mpeg_decode_slice(s, mb_y, &buf, s->gb.buffer_end - buf);
1993         emms_c();
1994         ff_dlog(c, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1995                 ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y,
1996                 s->start_mb_y, s->end_mb_y, s->er.error_count);
1997         if (ret < 0) {
1998             if (c->err_recognition & AV_EF_EXPLODE)
1999                 return ret;
2000             if (s->resync_mb_x >= 0 && s->resync_mb_y >= 0)
2001                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2002                                 s->mb_x, s->mb_y,
2003                                 ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2004         } else {
2005             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2006                             s->mb_x - 1, s->mb_y,
2007                             ER_AC_END | ER_DC_END | ER_MV_END);
2008         }
2009
2010         if (s->mb_y == s->end_mb_y)
2011             return 0;
2012
2013         start_code = -1;
2014         buf        = avpriv_find_start_code(buf, s->gb.buffer_end, &start_code);
2015         mb_y       = start_code - SLICE_MIN_START_CODE;
2016         if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
2017             mb_y += (*buf&0xE0)<<2;
2018         mb_y <<= field_pic;
2019         if (s->picture_structure == PICT_BOTTOM_FIELD)
2020             mb_y++;
2021         if (mb_y < 0 || mb_y >= s->end_mb_y)
2022             return AVERROR_INVALIDDATA;
2023     }
2024 }
2025
2026 /**
2027  * Handle slice ends.
2028  * @return 1 if it seems to be the last slice
2029  */
2030 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
2031 {
2032     Mpeg1Context *s1  = avctx->priv_data;
2033     MpegEncContext *s = &s1->mpeg_enc_ctx;
2034
2035     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
2036         return 0;
2037
2038     if (s->avctx->hwaccel) {
2039         int ret = s->avctx->hwaccel->end_frame(s->avctx);
2040         if (ret < 0) {
2041             av_log(avctx, AV_LOG_ERROR,
2042                    "hardware accelerator failed to decode picture\n");
2043             return ret;
2044         }
2045     }
2046
2047     /* end of slice reached */
2048     if (/* s->mb_y << field_pic == s->mb_height && */ !s->first_field && !s1->first_slice) {
2049         /* end of image */
2050
2051         ff_er_frame_end(&s->er);
2052
2053         ff_mpv_frame_end(s);
2054
2055         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
2056             int ret = av_frame_ref(pict, s->current_picture_ptr->f);
2057             if (ret < 0)
2058                 return ret;
2059             ff_print_debug_info(s, s->current_picture_ptr, pict);
2060             ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2061         } else {
2062             if (avctx->active_thread_type & FF_THREAD_FRAME)
2063                 s->picture_number++;
2064             /* latency of 1 frame for I- and P-frames */
2065             /* XXX: use another variable than picture_number */
2066             if (s->last_picture_ptr) {
2067                 int ret = av_frame_ref(pict, s->last_picture_ptr->f);
2068                 if (ret < 0)
2069                     return ret;
2070                 ff_print_debug_info(s, s->last_picture_ptr, pict);
2071                 ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2072             }
2073         }
2074
2075         return 1;
2076     } else {
2077         return 0;
2078     }
2079 }
2080
2081 static int mpeg1_decode_sequence(AVCodecContext *avctx,
2082                                  const uint8_t *buf, int buf_size)
2083 {
2084     Mpeg1Context *s1  = avctx->priv_data;
2085     MpegEncContext *s = &s1->mpeg_enc_ctx;
2086     int width, height;
2087     int i, v, j;
2088
2089     init_get_bits(&s->gb, buf, buf_size * 8);
2090
2091     width  = get_bits(&s->gb, 12);
2092     height = get_bits(&s->gb, 12);
2093     if (width == 0 || height == 0) {
2094         av_log(avctx, AV_LOG_WARNING,
2095                "Invalid horizontal or vertical size value.\n");
2096         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2097             return AVERROR_INVALIDDATA;
2098     }
2099     s->aspect_ratio_info = get_bits(&s->gb, 4);
2100     if (s->aspect_ratio_info == 0) {
2101         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
2102         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2103             return AVERROR_INVALIDDATA;
2104     }
2105     s->frame_rate_index = get_bits(&s->gb, 4);
2106     if (s->frame_rate_index == 0 || s->frame_rate_index > 13) {
2107         av_log(avctx, AV_LOG_WARNING,
2108                "frame_rate_index %d is invalid\n", s->frame_rate_index);
2109         s->frame_rate_index = 1;
2110     }
2111     s->bit_rate = get_bits(&s->gb, 18) * 400LL;
2112     if (check_marker(s->avctx, &s->gb, "in sequence header") == 0) {
2113         return AVERROR_INVALIDDATA;
2114     }
2115
2116     s->avctx->rc_buffer_size = get_bits(&s->gb, 10) * 1024 * 16;
2117     skip_bits(&s->gb, 1);
2118
2119     /* get matrix */
2120     if (get_bits1(&s->gb)) {
2121         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2122     } else {
2123         for (i = 0; i < 64; i++) {
2124             j = s->idsp.idct_permutation[i];
2125             v = ff_mpeg1_default_intra_matrix[i];
2126             s->intra_matrix[j]        = v;
2127             s->chroma_intra_matrix[j] = v;
2128         }
2129     }
2130     if (get_bits1(&s->gb)) {
2131         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2132     } else {
2133         for (i = 0; i < 64; i++) {
2134             int j = s->idsp.idct_permutation[i];
2135             v = ff_mpeg1_default_non_intra_matrix[i];
2136             s->inter_matrix[j]        = v;
2137             s->chroma_inter_matrix[j] = v;
2138         }
2139     }
2140
2141     if (show_bits(&s->gb, 23) != 0) {
2142         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2143         return AVERROR_INVALIDDATA;
2144     }
2145
2146     s->width  = width;
2147     s->height = height;
2148
2149     /* We set MPEG-2 parameters so that it emulates MPEG-1. */
2150     s->progressive_sequence = 1;
2151     s->progressive_frame    = 1;
2152     s->picture_structure    = PICT_FRAME;
2153     s->first_field          = 0;
2154     s->frame_pred_frame_dct = 1;
2155     s->chroma_format        = 1;
2156     s->codec_id             =
2157     s->avctx->codec_id      = AV_CODEC_ID_MPEG1VIDEO;
2158     s->out_format           = FMT_MPEG1;
2159     s->swap_uv              = 0; // AFAIK VCR2 does not have SEQ_HEADER
2160     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
2161         s->low_delay = 1;
2162
2163     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2164         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%"PRId64", aspect_ratio_info: %d \n",
2165                s->avctx->rc_buffer_size, s->bit_rate, s->aspect_ratio_info);
2166
2167     return 0;
2168 }
2169
2170 static int vcr2_init_sequence(AVCodecContext *avctx)
2171 {
2172     Mpeg1Context *s1  = avctx->priv_data;
2173     MpegEncContext *s = &s1->mpeg_enc_ctx;
2174     int i, v, ret;
2175
2176     /* start new MPEG-1 context decoding */
2177     s->out_format = FMT_MPEG1;
2178     if (s1->mpeg_enc_ctx_allocated) {
2179         ff_mpv_common_end(s);
2180         s1->mpeg_enc_ctx_allocated = 0;
2181     }
2182     s->width            = avctx->coded_width;
2183     s->height           = avctx->coded_height;
2184     avctx->has_b_frames = 0; // true?
2185     s->low_delay        = 1;
2186
2187     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2188     setup_hwaccel_for_pixfmt(avctx);
2189
2190     ff_mpv_idct_init(s);
2191     if ((ret = ff_mpv_common_init(s)) < 0)
2192         return ret;
2193     s1->mpeg_enc_ctx_allocated = 1;
2194
2195     for (i = 0; i < 64; i++) {
2196         int j = s->idsp.idct_permutation[i];
2197         v = ff_mpeg1_default_intra_matrix[i];
2198         s->intra_matrix[j]        = v;
2199         s->chroma_intra_matrix[j] = v;
2200
2201         v = ff_mpeg1_default_non_intra_matrix[i];
2202         s->inter_matrix[j]        = v;
2203         s->chroma_inter_matrix[j] = v;
2204     }
2205
2206     s->progressive_sequence  = 1;
2207     s->progressive_frame     = 1;
2208     s->picture_structure     = PICT_FRAME;
2209     s->first_field           = 0;
2210     s->frame_pred_frame_dct  = 1;
2211     s->chroma_format         = 1;
2212     if (s->codec_tag == AV_RL32("BW10")) {
2213         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
2214     } else {
2215         s->swap_uv = 1; // in case of xvmc we need to swap uv for each MB
2216         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
2217     }
2218     s1->save_width           = s->width;
2219     s1->save_height          = s->height;
2220     s1->save_progressive_seq = s->progressive_sequence;
2221     return 0;
2222 }
2223
2224 static int mpeg_decode_a53_cc(AVCodecContext *avctx,
2225                               const uint8_t *p, int buf_size)
2226 {
2227     Mpeg1Context *s1 = avctx->priv_data;
2228
2229     if (buf_size >= 6 &&
2230         p[0] == 'G' && p[1] == 'A' && p[2] == '9' && p[3] == '4' &&
2231         p[4] == 3 && (p[5] & 0x40)) {
2232         /* extract A53 Part 4 CC data */
2233         int cc_count = p[5] & 0x1f;
2234         if (cc_count > 0 && buf_size >= 7 + cc_count * 3) {
2235             av_freep(&s1->a53_caption);
2236             s1->a53_caption_size = cc_count * 3;
2237             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2238             if (!s1->a53_caption) {
2239                 s1->a53_caption_size = 0;
2240             } else {
2241                 memcpy(s1->a53_caption, p + 7, s1->a53_caption_size);
2242             }
2243             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
2244         }
2245         return 1;
2246     } else if (buf_size >= 2 &&
2247                p[0] == 0x03 && (p[1]&0x7f) == 0x01) {
2248         /* extract SCTE-20 CC data */
2249         GetBitContext gb;
2250         int cc_count = 0;
2251         int i;
2252
2253         init_get_bits(&gb, p + 2, buf_size - 2);
2254         cc_count = get_bits(&gb, 5);
2255         if (cc_count > 0) {
2256             av_freep(&s1->a53_caption);
2257             s1->a53_caption_size = cc_count * 3;
2258             s1->a53_caption      = av_mallocz(s1->a53_caption_size);
2259             if (!s1->a53_caption) {
2260                 s1->a53_caption_size = 0;
2261             } else {
2262                 uint8_t field, cc1, cc2;
2263                 uint8_t *cap = s1->a53_caption;
2264                 for (i = 0; i < cc_count && get_bits_left(&gb) >= 26; i++) {
2265                     skip_bits(&gb, 2); // priority
2266                     field = get_bits(&gb, 2);
2267                     skip_bits(&gb, 5); // line_offset
2268                     cc1 = get_bits(&gb, 8);
2269                     cc2 = get_bits(&gb, 8);
2270                     skip_bits(&gb, 1); // marker
2271
2272                     if (!field) { // forbidden
2273                         cap[0] = cap[1] = cap[2] = 0x00;
2274                     } else {
2275                         field = (field == 2 ? 1 : 0);
2276                         if (!s1->mpeg_enc_ctx.top_field_first) field = !field;
2277                         cap[0] = 0x04 | field;
2278                         cap[1] = ff_reverse[cc1];
2279                         cap[2] = ff_reverse[cc2];
2280                     }
2281                     cap += 3;
2282                 }
2283             }
2284             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
2285         }
2286         return 1;
2287     } else if (buf_size >= 11 &&
2288                p[0] == 'C' && p[1] == 'C' && p[2] == 0x01 && p[3] == 0xf8) {
2289         /* extract DVD CC data
2290          *
2291          * uint32_t   user_data_start_code        0x000001B2    (big endian)
2292          * uint16_t   user_identifier             0x4343 "CC"
2293          * uint8_t    user_data_type_code         0x01
2294          * uint8_t    caption_block_size          0xF8
2295          * uint8_t
2296          *   bit 7    caption_odd_field_first     1=odd field (CC1/CC2) first  0=even field (CC3/CC4) first
2297          *   bit 6    caption_filler              0
2298          *   bit 5:1  caption_block_count         number of caption blocks (pairs of caption words = frames). Most DVDs use 15 per start of GOP.
2299          *   bit 0    caption_extra_field_added   1=one additional caption word
2300          *
2301          * struct caption_field_block {
2302          *   uint8_t
2303          *     bit 7:1 caption_filler             0x7F (all 1s)
2304          *     bit 0   caption_field_odd          1=odd field (this is CC1/CC2)  0=even field (this is CC3/CC4)
2305          *   uint8_t   caption_first_byte
2306          *   uint8_t   caption_second_byte
2307          * } caption_block[(caption_block_count * 2) + caption_extra_field_added];
2308          *
2309          * Some DVDs encode caption data for both fields with caption_field_odd=1. The only way to decode the fields
2310          * correctly is to start on the field indicated by caption_odd_field_first and count between odd/even fields.
2311          * Don't assume that the first caption word is the odd field. There do exist MPEG files in the wild that start
2312          * on the even field. There also exist DVDs in the wild that encode an odd field count and the
2313          * caption_extra_field_added/caption_odd_field_first bits change per packet to allow that. */
2314         int cc_count = 0;
2315         int i;
2316         // There is a caption count field in the data, but it is often
2317         // incorrect.  So count the number of captions present.
2318         for (i = 5; i + 6 <= buf_size && ((p[i] & 0xfe) == 0xfe); i += 6)
2319             cc_count++;
2320         // Transform the DVD format into A53 Part 4 format
2321         if (cc_count > 0) {
2322             av_freep(&s1->a53_caption);
2323             s1->a53_caption_size = cc_count * 6;
2324             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2325             if (!s1->a53_caption) {
2326                 s1->a53_caption_size = 0;
2327             } else {
2328                 uint8_t field1 = !!(p[4] & 0x80);
2329                 uint8_t *cap = s1->a53_caption;
2330                 p += 5;
2331                 for (i = 0; i < cc_count; i++) {
2332                     cap[0] = (p[0] == 0xff && field1) ? 0xfc : 0xfd;
2333                     cap[1] = p[1];
2334                     cap[2] = p[2];
2335                     cap[3] = (p[3] == 0xff && !field1) ? 0xfc : 0xfd;
2336                     cap[4] = p[4];
2337                     cap[5] = p[5];
2338                     cap += 6;
2339                     p += 6;
2340                 }
2341             }
2342             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
2343         }
2344         return 1;
2345     }
2346     return 0;
2347 }
2348
2349 static void mpeg_decode_user_data(AVCodecContext *avctx,
2350                                   const uint8_t *p, int buf_size)
2351 {
2352     Mpeg1Context *s = avctx->priv_data;
2353     const uint8_t *buf_end = p + buf_size;
2354     Mpeg1Context *s1 = avctx->priv_data;
2355
2356 #if 0
2357     int i;
2358     for(i=0; !(!p[i-2] && !p[i-1] && p[i]==1) && i<buf_size; i++){
2359         av_log(avctx, AV_LOG_ERROR, "%c", p[i]);
2360     }
2361     av_log(avctx, AV_LOG_ERROR, "\n");
2362 #endif
2363
2364     if (buf_size > 29){
2365         int i;
2366         for(i=0; i<20; i++)
2367             if (!memcmp(p+i, "\0TMPGEXS\0", 9)){
2368                 s->tmpgexs= 1;
2369             }
2370     }
2371     /* we parse the DTG active format information */
2372     if (buf_end - p >= 5 &&
2373         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2374         int flags = p[4];
2375         p += 5;
2376         if (flags & 0x80) {
2377             /* skip event id */
2378             p += 2;
2379         }
2380         if (flags & 0x40) {
2381             if (buf_end - p < 1)
2382                 return;
2383             s1->has_afd = 1;
2384             s1->afd     = p[0] & 0x0f;
2385         }
2386     } else if (buf_end - p >= 6 &&
2387                p[0] == 'J' && p[1] == 'P' && p[2] == '3' && p[3] == 'D' &&
2388                p[4] == 0x03) { // S3D_video_format_length
2389         // the 0x7F mask ignores the reserved_bit value
2390         const uint8_t S3D_video_format_type = p[5] & 0x7F;
2391
2392         if (S3D_video_format_type == 0x03 ||
2393             S3D_video_format_type == 0x04 ||
2394             S3D_video_format_type == 0x08 ||
2395             S3D_video_format_type == 0x23) {
2396
2397             s1->has_stereo3d = 1;
2398
2399             switch (S3D_video_format_type) {
2400             case 0x03:
2401                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE;
2402                 break;
2403             case 0x04:
2404                 s1->stereo3d.type = AV_STEREO3D_TOPBOTTOM;
2405                 break;
2406             case 0x08:
2407                 s1->stereo3d.type = AV_STEREO3D_2D;
2408                 break;
2409             case 0x23:
2410                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
2411                 break;
2412             }
2413         }
2414     } else if (mpeg_decode_a53_cc(avctx, p, buf_size)) {
2415         return;
2416     }
2417 }
2418
2419 static void mpeg_decode_gop(AVCodecContext *avctx,
2420                             const uint8_t *buf, int buf_size)
2421 {
2422     Mpeg1Context *s1  = avctx->priv_data;
2423     MpegEncContext *s = &s1->mpeg_enc_ctx;
2424     int broken_link;
2425     int64_t tc;
2426
2427     init_get_bits(&s->gb, buf, buf_size * 8);
2428
2429     tc = s-> timecode_frame_start = get_bits(&s->gb, 25);
2430
2431 #if FF_API_PRIVATE_OPT
2432 FF_DISABLE_DEPRECATION_WARNINGS
2433     avctx->timecode_frame_start = tc;
2434 FF_ENABLE_DEPRECATION_WARNINGS
2435 #endif
2436
2437     s->closed_gop = get_bits1(&s->gb);
2438     /* broken_link indicates that after editing the
2439      * reference frames of the first B-Frames after GOP I-Frame
2440      * are missing (open gop) */
2441     broken_link = get_bits1(&s->gb);
2442
2443     if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2444         char tcbuf[AV_TIMECODE_STR_SIZE];
2445         av_timecode_make_mpeg_tc_string(tcbuf, tc);
2446         av_log(s->avctx, AV_LOG_DEBUG,
2447                "GOP (%s) closed_gop=%d broken_link=%d\n",
2448                tcbuf, s->closed_gop, broken_link);
2449     }
2450 }
2451
2452 static int decode_chunks(AVCodecContext *avctx, AVFrame *picture,
2453                          int *got_output, const uint8_t *buf, int buf_size)
2454 {
2455     Mpeg1Context *s = avctx->priv_data;
2456     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2457     const uint8_t *buf_ptr = buf;
2458     const uint8_t *buf_end = buf + buf_size;
2459     int ret, input_size;
2460     int last_code = 0, skip_frame = 0;
2461     int picture_start_code_seen = 0;
2462
2463     for (;;) {
2464         /* find next start code */
2465         uint32_t start_code = -1;
2466         buf_ptr = avpriv_find_start_code(buf_ptr, buf_end, &start_code);
2467         if (start_code > 0x1ff) {
2468             if (!skip_frame) {
2469                 if (HAVE_THREADS &&
2470                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2471                     !avctx->hwaccel) {
2472                     int i;
2473                     av_assert0(avctx->thread_count > 1);
2474
2475                     avctx->execute(avctx, slice_decode_thread,
2476                                    &s2->thread_context[0], NULL,
2477                                    s->slice_count, sizeof(void *));
2478                     for (i = 0; i < s->slice_count; i++)
2479                         s2->er.error_count += s2->thread_context[i]->er.error_count;
2480                 }
2481
2482                 ret = slice_end(avctx, picture);
2483                 if (ret < 0)
2484                     return ret;
2485                 else if (ret) {
2486                     // FIXME: merge with the stuff in mpeg_decode_slice
2487                     if (s2->last_picture_ptr || s2->low_delay)
2488                         *got_output = 1;
2489                 }
2490             }
2491             s2->pict_type = 0;
2492
2493             if (avctx->err_recognition & AV_EF_EXPLODE && s2->er.error_count)
2494                 return AVERROR_INVALIDDATA;
2495
2496             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2497         }
2498
2499         input_size = buf_end - buf_ptr;
2500
2501         if (avctx->debug & FF_DEBUG_STARTCODE)
2502             av_log(avctx, AV_LOG_DEBUG, "%3"PRIX32" at %"PTRDIFF_SPECIFIER" left %d\n",
2503                    start_code, buf_ptr - buf, input_size);
2504
2505         /* prepare data for next start code */
2506         switch (start_code) {
2507         case SEQ_START_CODE:
2508             if (last_code == 0) {
2509                 mpeg1_decode_sequence(avctx, buf_ptr, input_size);
2510                 if (buf != avctx->extradata)
2511                     s->sync = 1;
2512             } else {
2513                 av_log(avctx, AV_LOG_ERROR,
2514                        "ignoring SEQ_START_CODE after %X\n", last_code);
2515                 if (avctx->err_recognition & AV_EF_EXPLODE)
2516                     return AVERROR_INVALIDDATA;
2517             }
2518             break;
2519
2520         case PICTURE_START_CODE:
2521             if (picture_start_code_seen && s2->picture_structure == PICT_FRAME) {
2522                /* If it's a frame picture, there can't be more than one picture header.
2523                   Yet, it does happen and we need to handle it. */
2524                av_log(avctx, AV_LOG_WARNING, "ignoring extra picture following a frame-picture\n");
2525                break;
2526             }
2527             picture_start_code_seen = 1;
2528
2529             if (s2->width <= 0 || s2->height <= 0) {
2530                 av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d.\n",
2531                        s2->width, s2->height);
2532                 return AVERROR_INVALIDDATA;
2533             }
2534
2535             if (s->tmpgexs){
2536                 s2->intra_dc_precision= 3;
2537                 s2->intra_matrix[0]= 1;
2538             }
2539             if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) &&
2540                 !avctx->hwaccel && s->slice_count) {
2541                 int i;
2542
2543                 avctx->execute(avctx, slice_decode_thread,
2544                                s2->thread_context, NULL,
2545                                s->slice_count, sizeof(void *));
2546                 for (i = 0; i < s->slice_count; i++)
2547                     s2->er.error_count += s2->thread_context[i]->er.error_count;
2548                 s->slice_count = 0;
2549             }
2550             if (last_code == 0 || last_code == SLICE_MIN_START_CODE) {
2551                 ret = mpeg_decode_postinit(avctx);
2552                 if (ret < 0) {
2553                     av_log(avctx, AV_LOG_ERROR,
2554                            "mpeg_decode_postinit() failure\n");
2555                     return ret;
2556                 }
2557
2558                 /* We have a complete image: we try to decompress it. */
2559                 if (mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0)
2560                     s2->pict_type = 0;
2561                 s->first_slice = 1;
2562                 last_code      = PICTURE_START_CODE;
2563             } else {
2564                 av_log(avctx, AV_LOG_ERROR,
2565                        "ignoring pic after %X\n", last_code);
2566                 if (avctx->err_recognition & AV_EF_EXPLODE)
2567                     return AVERROR_INVALIDDATA;
2568             }
2569             break;
2570         case EXT_START_CODE:
2571             init_get_bits(&s2->gb, buf_ptr, input_size * 8);
2572
2573             switch (get_bits(&s2->gb, 4)) {
2574             case 0x1:
2575                 if (last_code == 0) {
2576                     mpeg_decode_sequence_extension(s);
2577                 } else {
2578                     av_log(avctx, AV_LOG_ERROR,
2579                            "ignoring seq ext after %X\n", last_code);
2580                     if (avctx->err_recognition & AV_EF_EXPLODE)
2581                         return AVERROR_INVALIDDATA;
2582                 }
2583                 break;
2584             case 0x2:
2585                 mpeg_decode_sequence_display_extension(s);
2586                 break;
2587             case 0x3:
2588                 mpeg_decode_quant_matrix_extension(s2);
2589                 break;
2590             case 0x7:
2591                 mpeg_decode_picture_display_extension(s);
2592                 break;
2593             case 0x8:
2594                 if (last_code == PICTURE_START_CODE) {
2595                     mpeg_decode_picture_coding_extension(s);
2596                 } else {
2597                     av_log(avctx, AV_LOG_ERROR,
2598                            "ignoring pic cod ext after %X\n", last_code);
2599                     if (avctx->err_recognition & AV_EF_EXPLODE)
2600                         return AVERROR_INVALIDDATA;
2601                 }
2602                 break;
2603             }
2604             break;
2605         case USER_START_CODE:
2606             mpeg_decode_user_data(avctx, buf_ptr, input_size);
2607             break;
2608         case GOP_START_CODE:
2609             if (last_code == 0) {
2610                 s2->first_field = 0;
2611                 mpeg_decode_gop(avctx, buf_ptr, input_size);
2612                 s->sync = 1;
2613             } else {
2614                 av_log(avctx, AV_LOG_ERROR,
2615                        "ignoring GOP_START_CODE after %X\n", last_code);
2616                 if (avctx->err_recognition & AV_EF_EXPLODE)
2617                     return AVERROR_INVALIDDATA;
2618             }
2619             break;
2620         default:
2621             if (start_code >= SLICE_MIN_START_CODE &&
2622                 start_code <= SLICE_MAX_START_CODE && last_code == PICTURE_START_CODE) {
2623                 if (s2->progressive_sequence && !s2->progressive_frame) {
2624                     s2->progressive_frame = 1;
2625                     av_log(s2->avctx, AV_LOG_ERROR,
2626                            "interlaced frame in progressive sequence, ignoring\n");
2627                 }
2628
2629                 if (s2->picture_structure == 0 ||
2630                     (s2->progressive_frame && s2->picture_structure != PICT_FRAME)) {
2631                     av_log(s2->avctx, AV_LOG_ERROR,
2632                            "picture_structure %d invalid, ignoring\n",
2633                            s2->picture_structure);
2634                     s2->picture_structure = PICT_FRAME;
2635                 }
2636
2637                 if (s2->progressive_sequence && !s2->frame_pred_frame_dct)
2638                     av_log(s2->avctx, AV_LOG_WARNING, "invalid frame_pred_frame_dct\n");
2639
2640                 if (s2->picture_structure == PICT_FRAME) {
2641                     s2->first_field = 0;
2642                     s2->v_edge_pos  = 16 * s2->mb_height;
2643                 } else {
2644                     s2->first_field ^= 1;
2645                     s2->v_edge_pos   = 8 * s2->mb_height;
2646                     memset(s2->mbskip_table, 0, s2->mb_stride * s2->mb_height);
2647                 }
2648             }
2649             if (start_code >= SLICE_MIN_START_CODE &&
2650                 start_code <= SLICE_MAX_START_CODE && last_code != 0) {
2651                 const int field_pic = s2->picture_structure != PICT_FRAME;
2652                 int mb_y = start_code - SLICE_MIN_START_CODE;
2653                 last_code = SLICE_MIN_START_CODE;
2654                 if (s2->codec_id != AV_CODEC_ID_MPEG1VIDEO && s2->mb_height > 2800/16)
2655                     mb_y += (*buf_ptr&0xE0)<<2;
2656
2657                 mb_y <<= field_pic;
2658                 if (s2->picture_structure == PICT_BOTTOM_FIELD)
2659                     mb_y++;
2660
2661                 if (buf_end - buf_ptr < 2) {
2662                     av_log(s2->avctx, AV_LOG_ERROR, "slice too small\n");
2663                     return AVERROR_INVALIDDATA;
2664                 }
2665
2666                 if (mb_y >= s2->mb_height) {
2667                     av_log(s2->avctx, AV_LOG_ERROR,
2668                            "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2669                     return AVERROR_INVALIDDATA;
2670                 }
2671
2672                 if (!s2->last_picture_ptr) {
2673                     /* Skip B-frames if we do not have reference frames and
2674                      * GOP is not closed. */
2675                     if (s2->pict_type == AV_PICTURE_TYPE_B) {
2676                         if (!s2->closed_gop) {
2677                             skip_frame = 1;
2678                             av_log(s2->avctx, AV_LOG_DEBUG,
2679                                    "Skipping B slice due to open GOP\n");
2680                             break;
2681                         }
2682                     }
2683                 }
2684                 if (s2->pict_type == AV_PICTURE_TYPE_I || (s2->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL))
2685                     s->sync = 1;
2686                 if (!s2->next_picture_ptr) {
2687                     /* Skip P-frames if we do not have a reference frame or
2688                      * we have an invalid header. */
2689                     if (s2->pict_type == AV_PICTURE_TYPE_P && !s->sync) {
2690                         skip_frame = 1;
2691                         av_log(s2->avctx, AV_LOG_DEBUG,
2692                                "Skipping P slice due to !sync\n");
2693                         break;
2694                     }
2695                 }
2696                 if ((avctx->skip_frame >= AVDISCARD_NONREF &&
2697                      s2->pict_type == AV_PICTURE_TYPE_B) ||
2698                     (avctx->skip_frame >= AVDISCARD_NONKEY &&
2699                      s2->pict_type != AV_PICTURE_TYPE_I) ||
2700                     avctx->skip_frame >= AVDISCARD_ALL) {
2701                     skip_frame = 1;
2702                     break;
2703                 }
2704
2705                 if (!s->mpeg_enc_ctx_allocated)
2706                     break;
2707
2708                 if (s2->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
2709                     if (mb_y < avctx->skip_top ||
2710                         mb_y >= s2->mb_height - avctx->skip_bottom)
2711                         break;
2712                 }
2713
2714                 if (!s2->pict_type) {
2715                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2716                     if (avctx->err_recognition & AV_EF_EXPLODE)
2717                         return AVERROR_INVALIDDATA;
2718                     break;
2719                 }
2720
2721                 if (s->first_slice) {
2722                     skip_frame     = 0;
2723                     s->first_slice = 0;
2724                     if ((ret = mpeg_field_start(s2, buf, buf_size)) < 0)
2725                         return ret;
2726                 }
2727                 if (!s2->current_picture_ptr) {
2728                     av_log(avctx, AV_LOG_ERROR,
2729                            "current_picture not initialized\n");
2730                     return AVERROR_INVALIDDATA;
2731                 }
2732
2733                 if (HAVE_THREADS &&
2734                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2735                     !avctx->hwaccel) {
2736                     int threshold = (s2->mb_height * s->slice_count +
2737                                      s2->slice_context_count / 2) /
2738                                     s2->slice_context_count;
2739                     av_assert0(avctx->thread_count > 1);
2740                     if (threshold <= mb_y) {
2741                         MpegEncContext *thread_context = s2->thread_context[s->slice_count];
2742
2743                         thread_context->start_mb_y = mb_y;
2744                         thread_context->end_mb_y   = s2->mb_height;
2745                         if (s->slice_count) {
2746                             s2->thread_context[s->slice_count - 1]->end_mb_y = mb_y;
2747                             ret = ff_update_duplicate_context(thread_context, s2);
2748                             if (ret < 0)
2749                                 return ret;
2750                         }
2751                         init_get_bits(&thread_context->gb, buf_ptr, input_size * 8);
2752                         s->slice_count++;
2753                     }
2754                     buf_ptr += 2; // FIXME add minimum number of bytes per slice
2755                 } else {
2756                     ret = mpeg_decode_slice(s2, mb_y, &buf_ptr, input_size);
2757                     emms_c();
2758
2759                     if (ret < 0) {
2760                         if (avctx->err_recognition & AV_EF_EXPLODE)
2761                             return ret;
2762                         if (s2->resync_mb_x >= 0 && s2->resync_mb_y >= 0)
2763                             ff_er_add_slice(&s2->er, s2->resync_mb_x,
2764                                             s2->resync_mb_y, s2->mb_x, s2->mb_y,
2765                                             ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2766                     } else {
2767                         ff_er_add_slice(&s2->er, s2->resync_mb_x,
2768                                         s2->resync_mb_y, s2->mb_x - 1, s2->mb_y,
2769                                         ER_AC_END | ER_DC_END | ER_MV_END);
2770                     }
2771                 }
2772             }
2773             break;
2774         }
2775     }
2776 }
2777
2778 static int mpeg_decode_frame(AVCodecContext *avctx, void *data,
2779                              int *got_output, AVPacket *avpkt)
2780 {
2781     const uint8_t *buf = avpkt->data;
2782     int ret;
2783     int buf_size = avpkt->size;
2784     Mpeg1Context *s = avctx->priv_data;
2785     AVFrame *picture = data;
2786     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2787
2788     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2789         /* special case for last picture */
2790         if (s2->low_delay == 0 && s2->next_picture_ptr) {
2791             int ret = av_frame_ref(picture, s2->next_picture_ptr->f);
2792             if (ret < 0)
2793                 return ret;
2794
2795             s2->next_picture_ptr = NULL;
2796
2797             *got_output = 1;
2798         }
2799         return buf_size;
2800     }
2801
2802     if (s2->avctx->flags & AV_CODEC_FLAG_TRUNCATED) {
2803         int next = ff_mpeg1_find_frame_end(&s2->parse_context, buf,
2804                                            buf_size, NULL);
2805
2806         if (ff_combine_frame(&s2->parse_context, next,
2807                              (const uint8_t **) &buf, &buf_size) < 0)
2808             return buf_size;
2809     }
2810
2811     s2->codec_tag = avpriv_toupper4(avctx->codec_tag);
2812     if (s->mpeg_enc_ctx_allocated == 0 && (   s2->codec_tag == AV_RL32("VCR2")
2813                                            || s2->codec_tag == AV_RL32("BW10")
2814                                           ))
2815         vcr2_init_sequence(avctx);
2816
2817     s->slice_count = 0;
2818
2819     if (avctx->extradata && !s->extradata_decoded) {
2820         ret = decode_chunks(avctx, picture, got_output,
2821                             avctx->extradata, avctx->extradata_size);
2822         if (*got_output) {
2823             av_log(avctx, AV_LOG_ERROR, "picture in extradata\n");
2824             av_frame_unref(picture);
2825             *got_output = 0;
2826         }
2827         s->extradata_decoded = 1;
2828         if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) {
2829             s2->current_picture_ptr = NULL;
2830             return ret;
2831         }
2832     }
2833
2834     ret = decode_chunks(avctx, picture, got_output, buf, buf_size);
2835     if (ret<0 || *got_output) {
2836         s2->current_picture_ptr = NULL;
2837
2838         if (s2->timecode_frame_start != -1 && *got_output) {
2839             AVFrameSideData *tcside = av_frame_new_side_data(picture,
2840                                                              AV_FRAME_DATA_GOP_TIMECODE,
2841                                                              sizeof(int64_t));
2842             if (!tcside)
2843                 return AVERROR(ENOMEM);
2844             memcpy(tcside->data, &s2->timecode_frame_start, sizeof(int64_t));
2845
2846             s2->timecode_frame_start = -1;
2847         }
2848     }
2849
2850     return ret;
2851 }
2852
2853 static void flush(AVCodecContext *avctx)
2854 {
2855     Mpeg1Context *s = avctx->priv_data;
2856
2857     s->sync       = 0;
2858
2859     ff_mpeg_flush(avctx);
2860 }
2861
2862 static av_cold int mpeg_decode_end(AVCodecContext *avctx)
2863 {
2864     Mpeg1Context *s = avctx->priv_data;
2865
2866     if (s->mpeg_enc_ctx_allocated)
2867         ff_mpv_common_end(&s->mpeg_enc_ctx);
2868     av_freep(&s->a53_caption);
2869     return 0;
2870 }
2871
2872 AVCodec ff_mpeg1video_decoder = {
2873     .name                  = "mpeg1video",
2874     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2875     .type                  = AVMEDIA_TYPE_VIDEO,
2876     .id                    = AV_CODEC_ID_MPEG1VIDEO,
2877     .priv_data_size        = sizeof(Mpeg1Context),
2878     .init                  = mpeg_decode_init,
2879     .close                 = mpeg_decode_end,
2880     .decode                = mpeg_decode_frame,
2881     .capabilities          = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2882                              AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2883                              AV_CODEC_CAP_SLICE_THREADS,
2884     .caps_internal         = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
2885     .flush                 = flush,
2886     .max_lowres            = 3,
2887     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context)
2888 };
2889
2890 AVCodec ff_mpeg2video_decoder = {
2891     .name           = "mpeg2video",
2892     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2893     .type           = AVMEDIA_TYPE_VIDEO,
2894     .id             = AV_CODEC_ID_MPEG2VIDEO,
2895     .priv_data_size = sizeof(Mpeg1Context),
2896     .init           = mpeg_decode_init,
2897     .close          = mpeg_decode_end,
2898     .decode         = mpeg_decode_frame,
2899     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2900                       AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2901                       AV_CODEC_CAP_SLICE_THREADS,
2902     .caps_internal  = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
2903     .flush          = flush,
2904     .max_lowres     = 3,
2905     .profiles       = NULL_IF_CONFIG_SMALL(ff_mpeg2_video_profiles),
2906 };
2907
2908 //legacy decoder
2909 AVCodec ff_mpegvideo_decoder = {
2910     .name           = "mpegvideo",
2911     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2912     .type           = AVMEDIA_TYPE_VIDEO,
2913     .id             = AV_CODEC_ID_MPEG2VIDEO,
2914     .priv_data_size = sizeof(Mpeg1Context),
2915     .init           = mpeg_decode_init,
2916     .close          = mpeg_decode_end,
2917     .decode         = mpeg_decode_frame,
2918     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS,
2919     .caps_internal  = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
2920     .flush          = flush,
2921     .max_lowres     = 3,
2922 };