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