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nutdec.c
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1 /*
2  * "NUT" Container Format demuxer
3  * Copyright (c) 2004-2006 Michael Niedermayer
4  * Copyright (c) 2003 Alex Beregszaszi
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 #include "libavutil/avstring.h"
24 #include "libavutil/avassert.h"
25 #include "libavutil/bswap.h"
26 #include "libavutil/dict.h"
27 #include "libavutil/mathematics.h"
28 #include "libavutil/tree.h"
29 #include "avio_internal.h"
30 #include "nut.h"
31 #include "riff.h"
32 
33 #define NUT_MAX_STREAMS 256 /* arbitrary sanity check value */
34 
35 static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index,
36  int64_t *pos_arg, int64_t pos_limit);
37 
38 static int get_str(AVIOContext *bc, char *string, unsigned int maxlen)
39 {
40  unsigned int len = ffio_read_varlen(bc);
41 
42  if (len && maxlen)
43  avio_read(bc, string, FFMIN(len, maxlen));
44  while (len > maxlen) {
45  avio_r8(bc);
46  len--;
47  }
48 
49  if (maxlen)
50  string[FFMIN(len, maxlen - 1)] = 0;
51 
52  if (maxlen == len)
53  return -1;
54  else
55  return 0;
56 }
57 
58 static int64_t get_s(AVIOContext *bc)
59 {
60  int64_t v = ffio_read_varlen(bc) + 1;
61 
62  if (v & 1)
63  return -(v >> 1);
64  else
65  return (v >> 1);
66 }
67 
68 static uint64_t get_fourcc(AVIOContext *bc)
69 {
70  unsigned int len = ffio_read_varlen(bc);
71 
72  if (len == 2)
73  return avio_rl16(bc);
74  else if (len == 4)
75  return avio_rl32(bc);
76  else {
77  av_log(NULL, AV_LOG_ERROR, "Unsupported fourcc length %d\n", len);
78  return -1;
79  }
80 }
81 
82 #ifdef TRACE
83 static inline uint64_t get_v_trace(AVIOContext *bc, const char *file,
84  const char *func, int line)
85 {
86  uint64_t v = ffio_read_varlen(bc);
87 
88  av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n",
89  v, v, file, func, line);
90  return v;
91 }
92 
93 static inline int64_t get_s_trace(AVIOContext *bc, const char *file,
94  const char *func, int line)
95 {
96  int64_t v = get_s(bc);
97 
98  av_log(NULL, AV_LOG_DEBUG, "get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n",
99  v, v, file, func, line);
100  return v;
101 }
102 
103 static inline uint64_t get_4cc_trace(AVIOContext *bc, char *file,
104  char *func, int line)
105 {
106  uint64_t v = get_fourcc(bc);
107 
108  av_log(NULL, AV_LOG_DEBUG, "get_fourcc %5"PRId64" / %"PRIX64" in %s %s:%d\n",
109  v, v, file, func, line);
110  return v;
111 }
112 #define ffio_read_varlen(bc) get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
113 #define get_s(bc) get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
114 #define get_fourcc(bc) get_4cc_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
115 #endif
116 
118  int calculate_checksum, uint64_t startcode)
119 {
120  int64_t size;
121 // start = avio_tell(bc) - 8;
122 
123  startcode = av_be2ne64(startcode);
124  startcode = ff_crc04C11DB7_update(0, (uint8_t*) &startcode, 8);
125 
127  size = ffio_read_varlen(bc);
128  if (size > 4096)
129  avio_rb32(bc);
130  if (ffio_get_checksum(bc) && size > 4096)
131  return -1;
132 
133  ffio_init_checksum(bc, calculate_checksum ? ff_crc04C11DB7_update : NULL, 0);
134 
135  return size;
136 }
137 
138 static uint64_t find_any_startcode(AVIOContext *bc, int64_t pos)
139 {
140  uint64_t state = 0;
141 
142  if (pos >= 0)
143  /* Note, this may fail if the stream is not seekable, but that should
144  * not matter, as in this case we simply start where we currently are */
145  avio_seek(bc, pos, SEEK_SET);
146  while (!url_feof(bc)) {
147  state = (state << 8) | avio_r8(bc);
148  if ((state >> 56) != 'N')
149  continue;
150  switch (state) {
151  case MAIN_STARTCODE:
152  case STREAM_STARTCODE:
153  case SYNCPOINT_STARTCODE:
154  case INFO_STARTCODE:
155  case INDEX_STARTCODE:
156  return state;
157  }
158  }
159 
160  return 0;
161 }
162 
163 /**
164  * Find the given startcode.
165  * @param code the startcode
166  * @param pos the start position of the search, or -1 if the current position
167  * @return the position of the startcode or -1 if not found
168  */
169 static int64_t find_startcode(AVIOContext *bc, uint64_t code, int64_t pos)
170 {
171  for (;;) {
172  uint64_t startcode = find_any_startcode(bc, pos);
173  if (startcode == code)
174  return avio_tell(bc) - 8;
175  else if (startcode == 0)
176  return -1;
177  pos = -1;
178  }
179 }
180 
181 static int nut_probe(AVProbeData *p)
182 {
183  int i;
184  uint64_t code = 0;
185 
186  for (i = 0; i < p->buf_size; i++) {
187  code = (code << 8) | p->buf[i];
188  if (code == MAIN_STARTCODE)
189  return AVPROBE_SCORE_MAX;
190  }
191  return 0;
192 }
193 
194 #define GET_V(dst, check) \
195  do { \
196  tmp = ffio_read_varlen(bc); \
197  if (!(check)) { \
198  av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp); \
199  return AVERROR_INVALIDDATA; \
200  } \
201  dst = tmp; \
202  } while (0)
203 
204 static int skip_reserved(AVIOContext *bc, int64_t pos)
205 {
206  pos -= avio_tell(bc);
207  if (pos < 0) {
208  avio_seek(bc, pos, SEEK_CUR);
209  return AVERROR_INVALIDDATA;
210  } else {
211  while (pos--)
212  avio_r8(bc);
213  return 0;
214  }
215 }
216 
218 {
219  AVFormatContext *s = nut->avf;
220  AVIOContext *bc = s->pb;
221  uint64_t tmp, end;
222  unsigned int stream_count;
223  int i, j, count;
224  int tmp_stream, tmp_mul, tmp_pts, tmp_size, tmp_res, tmp_head_idx;
225 
226  end = get_packetheader(nut, bc, 1, MAIN_STARTCODE);
227  end += avio_tell(bc);
228 
229  tmp = ffio_read_varlen(bc);
230  if (tmp < 2 && tmp > NUT_VERSION) {
231  av_log(s, AV_LOG_ERROR, "Version %"PRId64" not supported.\n",
232  tmp);
233  return AVERROR(ENOSYS);
234  }
235 
236  GET_V(stream_count, tmp > 0 && tmp <= NUT_MAX_STREAMS);
237 
238  nut->max_distance = ffio_read_varlen(bc);
239  if (nut->max_distance > 65536) {
240  av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
241  nut->max_distance = 65536;
242  }
243 
244  GET_V(nut->time_base_count, tmp > 0 && tmp < INT_MAX / sizeof(AVRational));
245  nut->time_base = av_malloc(nut->time_base_count * sizeof(AVRational));
246 
247  for (i = 0; i < nut->time_base_count; i++) {
248  GET_V(nut->time_base[i].num, tmp > 0 && tmp < (1ULL << 31));
249  GET_V(nut->time_base[i].den, tmp > 0 && tmp < (1ULL << 31));
250  if (av_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1) {
251  av_log(s, AV_LOG_ERROR, "time base invalid\n");
252  return AVERROR_INVALIDDATA;
253  }
254  }
255  tmp_pts = 0;
256  tmp_mul = 1;
257  tmp_stream = 0;
258  tmp_head_idx = 0;
259  for (i = 0; i < 256;) {
260  int tmp_flags = ffio_read_varlen(bc);
261  int tmp_fields = ffio_read_varlen(bc);
262 
263  if (tmp_fields > 0)
264  tmp_pts = get_s(bc);
265  if (tmp_fields > 1)
266  tmp_mul = ffio_read_varlen(bc);
267  if (tmp_fields > 2)
268  tmp_stream = ffio_read_varlen(bc);
269  if (tmp_fields > 3)
270  tmp_size = ffio_read_varlen(bc);
271  else
272  tmp_size = 0;
273  if (tmp_fields > 4)
274  tmp_res = ffio_read_varlen(bc);
275  else
276  tmp_res = 0;
277  if (tmp_fields > 5)
278  count = ffio_read_varlen(bc);
279  else
280  count = tmp_mul - tmp_size;
281  if (tmp_fields > 6)
282  get_s(bc);
283  if (tmp_fields > 7)
284  tmp_head_idx = ffio_read_varlen(bc);
285 
286  while (tmp_fields-- > 8)
287  ffio_read_varlen(bc);
288 
289  if (count == 0 || i + count > 256) {
290  av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
291  return AVERROR_INVALIDDATA;
292  }
293  if (tmp_stream >= stream_count) {
294  av_log(s, AV_LOG_ERROR, "illegal stream number\n");
295  return AVERROR_INVALIDDATA;
296  }
297 
298  for (j = 0; j < count; j++, i++) {
299  if (i == 'N') {
300  nut->frame_code[i].flags = FLAG_INVALID;
301  j--;
302  continue;
303  }
304  nut->frame_code[i].flags = tmp_flags;
305  nut->frame_code[i].pts_delta = tmp_pts;
306  nut->frame_code[i].stream_id = tmp_stream;
307  nut->frame_code[i].size_mul = tmp_mul;
308  nut->frame_code[i].size_lsb = tmp_size + j;
309  nut->frame_code[i].reserved_count = tmp_res;
310  nut->frame_code[i].header_idx = tmp_head_idx;
311  }
312  }
313  av_assert0(nut->frame_code['N'].flags == FLAG_INVALID);
314 
315  if (end > avio_tell(bc) + 4) {
316  int rem = 1024;
317  GET_V(nut->header_count, tmp < 128U);
318  nut->header_count++;
319  for (i = 1; i < nut->header_count; i++) {
320  uint8_t *hdr;
321  GET_V(nut->header_len[i], tmp > 0 && tmp < 256);
322  rem -= nut->header_len[i];
323  if (rem < 0) {
324  av_log(s, AV_LOG_ERROR, "invalid elision header\n");
325  return AVERROR_INVALIDDATA;
326  }
327  hdr = av_malloc(nut->header_len[i]);
328  if (!hdr)
329  return AVERROR(ENOMEM);
330  avio_read(bc, hdr, nut->header_len[i]);
331  nut->header[i] = hdr;
332  }
333  av_assert0(nut->header_len[0] == 0);
334  }
335 
336  if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
337  av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
338  return AVERROR_INVALIDDATA;
339  }
340 
341  nut->stream = av_mallocz(sizeof(StreamContext) * stream_count);
342  for (i = 0; i < stream_count; i++)
343  avformat_new_stream(s, NULL);
344 
345  return 0;
346 }
347 
349 {
350  AVFormatContext *s = nut->avf;
351  AVIOContext *bc = s->pb;
352  StreamContext *stc;
353  int class, stream_id;
354  uint64_t tmp, end;
355  AVStream *st;
356 
357  end = get_packetheader(nut, bc, 1, STREAM_STARTCODE);
358  end += avio_tell(bc);
359 
360  GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
361  stc = &nut->stream[stream_id];
362  st = s->streams[stream_id];
363  if (!st)
364  return AVERROR(ENOMEM);
365 
366  class = ffio_read_varlen(bc);
367  tmp = get_fourcc(bc);
368  st->codec->codec_tag = tmp;
369  switch (class) {
370  case 0:
372  st->codec->codec_id = av_codec_get_id((const AVCodecTag * const []) {
375  0
376  },
377  tmp);
378  break;
379  case 1:
381  st->codec->codec_id = av_codec_get_id((const AVCodecTag * const []) {
384  0
385  },
386  tmp);
387  break;
388  case 2:
391  break;
392  case 3:
395  break;
396  default:
397  av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
398  return AVERROR(ENOSYS);
399  }
400  if (class < 3 && st->codec->codec_id == AV_CODEC_ID_NONE)
401  av_log(s, AV_LOG_ERROR,
402  "Unknown codec tag '0x%04x' for stream number %d\n",
403  (unsigned int) tmp, stream_id);
404 
405  GET_V(stc->time_base_id, tmp < nut->time_base_count);
406  GET_V(stc->msb_pts_shift, tmp < 16);
408  GET_V(stc->decode_delay, tmp < 1000); // sanity limit, raise this if Moore's law is true
409  st->codec->has_b_frames = stc->decode_delay;
410  ffio_read_varlen(bc); // stream flags
411 
412  GET_V(st->codec->extradata_size, tmp < (1 << 30));
413  if (st->codec->extradata_size) {
416  avio_read(bc, st->codec->extradata, st->codec->extradata_size);
417  }
418 
419  if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
420  GET_V(st->codec->width, tmp > 0);
421  GET_V(st->codec->height, tmp > 0);
424  if ((!st->sample_aspect_ratio.num) != (!st->sample_aspect_ratio.den)) {
425  av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n",
427  return AVERROR_INVALIDDATA;
428  }
429  ffio_read_varlen(bc); /* csp type */
430  } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
431  GET_V(st->codec->sample_rate, tmp > 0);
432  ffio_read_varlen(bc); // samplerate_den
433  GET_V(st->codec->channels, tmp > 0);
434  }
435  if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
436  av_log(s, AV_LOG_ERROR,
437  "stream header %d checksum mismatch\n", stream_id);
438  return AVERROR_INVALIDDATA;
439  }
440  stc->time_base = &nut->time_base[stc->time_base_id];
441  avpriv_set_pts_info(s->streams[stream_id], 63, stc->time_base->num,
442  stc->time_base->den);
443  return 0;
444 }
445 
447  int stream_id)
448 {
449  int flag = 0, i;
450 
451  for (i = 0; ff_nut_dispositions[i].flag; ++i)
452  if (!strcmp(ff_nut_dispositions[i].str, value))
453  flag = ff_nut_dispositions[i].flag;
454  if (!flag)
455  av_log(avf, AV_LOG_INFO, "unknown disposition type '%s'\n", value);
456  for (i = 0; i < avf->nb_streams; ++i)
457  if (stream_id == i || stream_id == -1)
458  avf->streams[i]->disposition |= flag;
459 }
460 
462 {
463  AVFormatContext *s = nut->avf;
464  AVIOContext *bc = s->pb;
465  uint64_t tmp, chapter_start, chapter_len;
466  unsigned int stream_id_plus1, count;
467  int chapter_id, i;
468  int64_t value, end;
469  char name[256], str_value[1024], type_str[256];
470  const char *type;
471  AVChapter *chapter = NULL;
472  AVStream *st = NULL;
473  AVDictionary **metadata = NULL;
474 
475  end = get_packetheader(nut, bc, 1, INFO_STARTCODE);
476  end += avio_tell(bc);
477 
478  GET_V(stream_id_plus1, tmp <= s->nb_streams);
479  chapter_id = get_s(bc);
480  chapter_start = ffio_read_varlen(bc);
481  chapter_len = ffio_read_varlen(bc);
482  count = ffio_read_varlen(bc);
483 
484  if (chapter_id && !stream_id_plus1) {
485  int64_t start = chapter_start / nut->time_base_count;
486  chapter = avpriv_new_chapter(s, chapter_id,
487  nut->time_base[chapter_start %
488  nut->time_base_count],
489  start, start + chapter_len, NULL);
490  metadata = &chapter->metadata;
491  } else if (stream_id_plus1) {
492  st = s->streams[stream_id_plus1 - 1];
493  metadata = &st->metadata;
494  } else
495  metadata = &s->metadata;
496 
497  for (i = 0; i < count; i++) {
498  get_str(bc, name, sizeof(name));
499  value = get_s(bc);
500  if (value == -1) {
501  type = "UTF-8";
502  get_str(bc, str_value, sizeof(str_value));
503  } else if (value == -2) {
504  get_str(bc, type_str, sizeof(type_str));
505  type = type_str;
506  get_str(bc, str_value, sizeof(str_value));
507  } else if (value == -3) {
508  type = "s";
509  value = get_s(bc);
510  } else if (value == -4) {
511  type = "t";
512  value = ffio_read_varlen(bc);
513  } else if (value < -4) {
514  type = "r";
515  get_s(bc);
516  } else {
517  type = "v";
518  }
519 
520  if (stream_id_plus1 > s->nb_streams) {
521  av_log(s, AV_LOG_ERROR, "invalid stream id for info packet\n");
522  continue;
523  }
524 
525  if (!strcmp(type, "UTF-8")) {
526  if (chapter_id == 0 && !strcmp(name, "Disposition")) {
527  set_disposition_bits(s, str_value, stream_id_plus1 - 1);
528  continue;
529  }
530 
531  if (stream_id_plus1 && !strcmp(name, "r_frame_rate")) {
532  sscanf(str_value, "%d/%d", &st->r_frame_rate.num, &st->r_frame_rate.den);
533  if (st->r_frame_rate.num >= 1000LL*st->r_frame_rate.den)
534  st->r_frame_rate.num = st->r_frame_rate.den = 0;
535  continue;
536  }
537 
538  if (metadata && av_strcasecmp(name, "Uses") &&
539  av_strcasecmp(name, "Depends") && av_strcasecmp(name, "Replaces"))
540  av_dict_set(metadata, name, str_value, 0);
541  }
542  }
543 
544  if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
545  av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
546  return AVERROR_INVALIDDATA;
547  }
548  return 0;
549 }
550 
551 static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr)
552 {
553  AVFormatContext *s = nut->avf;
554  AVIOContext *bc = s->pb;
555  int64_t end;
556  uint64_t tmp;
557 
558  nut->last_syncpoint_pos = avio_tell(bc) - 8;
559 
560  end = get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
561  end += avio_tell(bc);
562 
563  tmp = ffio_read_varlen(bc);
564  *back_ptr = nut->last_syncpoint_pos - 16 * ffio_read_varlen(bc);
565  if (*back_ptr < 0)
566  return AVERROR_INVALIDDATA;
567 
568  ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count],
569  tmp / nut->time_base_count);
570 
571  if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
572  av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
573  return AVERROR_INVALIDDATA;
574  }
575 
576  *ts = tmp / nut->time_base_count *
577  av_q2d(nut->time_base[tmp % nut->time_base_count]) * AV_TIME_BASE;
578  ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
579 
580  return 0;
581 }
582 
583 //FIXME calculate exactly, this is just a good approximation.
584 static int64_t find_duration(NUTContext *nut, int64_t filesize)
585 {
586  AVFormatContext *s = nut->avf;
587  int64_t duration = 0;
588 
589  ff_find_last_ts(s, -1, &duration, NULL, nut_read_timestamp);
590 
591  if(duration > 0)
593  return duration;
594 }
595 
597 {
598  AVFormatContext *s = nut->avf;
599  AVIOContext *bc = s->pb;
600  uint64_t tmp, end;
601  int i, j, syncpoint_count;
602  int64_t filesize = avio_size(bc);
603  int64_t *syncpoints;
604  uint64_t max_pts;
605  int8_t *has_keyframe;
606  int ret = AVERROR_INVALIDDATA;
607 
608  if(filesize <= 0)
609  return -1;
610 
611  avio_seek(bc, filesize - 12, SEEK_SET);
612  avio_seek(bc, filesize - avio_rb64(bc), SEEK_SET);
613  if (avio_rb64(bc) != INDEX_STARTCODE) {
614  av_log(s, AV_LOG_ERROR, "no index at the end\n");
615 
616  if(s->duration<=0)
617  s->duration = find_duration(nut, filesize);
618  return ret;
619  }
620 
621  end = get_packetheader(nut, bc, 1, INDEX_STARTCODE);
622  end += avio_tell(bc);
623 
624  max_pts = ffio_read_varlen(bc);
625  s->duration = av_rescale_q(max_pts / nut->time_base_count,
626  nut->time_base[max_pts % nut->time_base_count],
629 
630  GET_V(syncpoint_count, tmp < INT_MAX / 8 && tmp > 0);
631  syncpoints = av_malloc(sizeof(int64_t) * syncpoint_count);
632  has_keyframe = av_malloc(sizeof(int8_t) * (syncpoint_count + 1));
633  for (i = 0; i < syncpoint_count; i++) {
634  syncpoints[i] = ffio_read_varlen(bc);
635  if (syncpoints[i] <= 0)
636  goto fail;
637  if (i)
638  syncpoints[i] += syncpoints[i - 1];
639  }
640 
641  for (i = 0; i < s->nb_streams; i++) {
642  int64_t last_pts = -1;
643  for (j = 0; j < syncpoint_count;) {
644  uint64_t x = ffio_read_varlen(bc);
645  int type = x & 1;
646  int n = j;
647  x >>= 1;
648  if (type) {
649  int flag = x & 1;
650  x >>= 1;
651  if (n + x >= syncpoint_count + 1) {
652  av_log(s, AV_LOG_ERROR, "index overflow A %d + %"PRIu64" >= %d\n", n, x, syncpoint_count + 1);
653  goto fail;
654  }
655  while (x--)
656  has_keyframe[n++] = flag;
657  has_keyframe[n++] = !flag;
658  } else {
659  while (x != 1) {
660  if (n >= syncpoint_count + 1) {
661  av_log(s, AV_LOG_ERROR, "index overflow B\n");
662  goto fail;
663  }
664  has_keyframe[n++] = x & 1;
665  x >>= 1;
666  }
667  }
668  if (has_keyframe[0]) {
669  av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
670  goto fail;
671  }
672  av_assert0(n <= syncpoint_count + 1);
673  for (; j < n && j < syncpoint_count; j++) {
674  if (has_keyframe[j]) {
675  uint64_t B, A = ffio_read_varlen(bc);
676  if (!A) {
677  A = ffio_read_varlen(bc);
678  B = ffio_read_varlen(bc);
679  // eor_pts[j][i] = last_pts + A + B
680  } else
681  B = 0;
682  av_add_index_entry(s->streams[i], 16 * syncpoints[j - 1],
683  last_pts + A, 0, 0, AVINDEX_KEYFRAME);
684  last_pts += A + B;
685  }
686  }
687  }
688  }
689 
690  if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
691  av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
692  goto fail;
693  }
694  ret = 0;
695 
696 fail:
697  av_free(syncpoints);
698  av_free(has_keyframe);
699  return ret;
700 }
701 
703 {
704  NUTContext *nut = s->priv_data;
705  AVIOContext *bc = s->pb;
706  int64_t pos;
707  int initialized_stream_count;
708 
709  nut->avf = s;
710 
711  /* main header */
712  pos = 0;
713  do {
714  pos = find_startcode(bc, MAIN_STARTCODE, pos) + 1;
715  if (pos < 0 + 1) {
716  av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
717  return AVERROR_INVALIDDATA;
718  }
719  } while (decode_main_header(nut) < 0);
720 
721  /* stream headers */
722  pos = 0;
723  for (initialized_stream_count = 0; initialized_stream_count < s->nb_streams;) {
724  pos = find_startcode(bc, STREAM_STARTCODE, pos) + 1;
725  if (pos < 0 + 1) {
726  av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
727  return AVERROR_INVALIDDATA;
728  }
729  if (decode_stream_header(nut) >= 0)
730  initialized_stream_count++;
731  }
732 
733  /* info headers */
734  pos = 0;
735  for (;;) {
736  uint64_t startcode = find_any_startcode(bc, pos);
737  pos = avio_tell(bc);
738 
739  if (startcode == 0) {
740  av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
741  return AVERROR_INVALIDDATA;
742  } else if (startcode == SYNCPOINT_STARTCODE) {
743  nut->next_startcode = startcode;
744  break;
745  } else if (startcode != INFO_STARTCODE) {
746  continue;
747  }
748 
749  decode_info_header(nut);
750  }
751 
752  s->data_offset = pos - 8;
753 
754  if (bc->seekable) {
755  int64_t orig_pos = avio_tell(bc);
757  avio_seek(bc, orig_pos, SEEK_SET);
758  }
760 
762 
763  return 0;
764 }
765 
766 static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id,
767  uint8_t *header_idx, int frame_code)
768 {
769  AVFormatContext *s = nut->avf;
770  AVIOContext *bc = s->pb;
771  StreamContext *stc;
772  int size, flags, size_mul, pts_delta, i, reserved_count;
773  uint64_t tmp;
774 
775  if (avio_tell(bc) > nut->last_syncpoint_pos + nut->max_distance) {
776  av_log(s, AV_LOG_ERROR,
777  "Last frame must have been damaged %"PRId64" > %"PRId64" + %d\n",
778  avio_tell(bc), nut->last_syncpoint_pos, nut->max_distance);
779  return AVERROR_INVALIDDATA;
780  }
781 
782  flags = nut->frame_code[frame_code].flags;
783  size_mul = nut->frame_code[frame_code].size_mul;
784  size = nut->frame_code[frame_code].size_lsb;
785  *stream_id = nut->frame_code[frame_code].stream_id;
786  pts_delta = nut->frame_code[frame_code].pts_delta;
787  reserved_count = nut->frame_code[frame_code].reserved_count;
788  *header_idx = nut->frame_code[frame_code].header_idx;
789 
790  if (flags & FLAG_INVALID)
791  return AVERROR_INVALIDDATA;
792  if (flags & FLAG_CODED)
793  flags ^= ffio_read_varlen(bc);
794  if (flags & FLAG_STREAM_ID) {
795  GET_V(*stream_id, tmp < s->nb_streams);
796  }
797  stc = &nut->stream[*stream_id];
798  if (flags & FLAG_CODED_PTS) {
799  int coded_pts = ffio_read_varlen(bc);
800  // FIXME check last_pts validity?
801  if (coded_pts < (1 << stc->msb_pts_shift)) {
802  *pts = ff_lsb2full(stc, coded_pts);
803  } else
804  *pts = coded_pts - (1LL << stc->msb_pts_shift);
805  } else
806  *pts = stc->last_pts + pts_delta;
807  if (flags & FLAG_SIZE_MSB)
808  size += size_mul * ffio_read_varlen(bc);
809  if (flags & FLAG_MATCH_TIME)
810  get_s(bc);
811  if (flags & FLAG_HEADER_IDX)
812  *header_idx = ffio_read_varlen(bc);
813  if (flags & FLAG_RESERVED)
814  reserved_count = ffio_read_varlen(bc);
815  for (i = 0; i < reserved_count; i++)
816  ffio_read_varlen(bc);
817 
818  if (*header_idx >= (unsigned)nut->header_count) {
819  av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
820  return AVERROR_INVALIDDATA;
821  }
822  if (size > 4096)
823  *header_idx = 0;
824  size -= nut->header_len[*header_idx];
825 
826  if (flags & FLAG_CHECKSUM) {
827  avio_rb32(bc); // FIXME check this
828  } else if (size > 2 * nut->max_distance || FFABS(stc->last_pts - *pts) >
829  stc->max_pts_distance) {
830  av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
831  return AVERROR_INVALIDDATA;
832  }
833 
834  stc->last_pts = *pts;
835  stc->last_flags = flags;
836 
837  return size;
838 }
839 
840 static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code)
841 {
842  AVFormatContext *s = nut->avf;
843  AVIOContext *bc = s->pb;
844  int size, stream_id, discard;
845  int64_t pts, last_IP_pts;
846  StreamContext *stc;
847  uint8_t header_idx;
848 
849  size = decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
850  if (size < 0)
851  return size;
852 
853  stc = &nut->stream[stream_id];
854 
855  if (stc->last_flags & FLAG_KEY)
856  stc->skip_until_key_frame = 0;
857 
858  discard = s->streams[stream_id]->discard;
859  last_IP_pts = s->streams[stream_id]->last_IP_pts;
860  if ((discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY)) ||
861  (discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE &&
862  last_IP_pts > pts) ||
863  discard >= AVDISCARD_ALL ||
864  stc->skip_until_key_frame) {
865  avio_skip(bc, size);
866  return 1;
867  }
868 
869  if (av_new_packet(pkt, size + nut->header_len[header_idx]) < 0)
870  return AVERROR(ENOMEM);
871  memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
872  pkt->pos = avio_tell(bc); // FIXME
873  avio_read(bc, pkt->data + nut->header_len[header_idx], size);
874 
875  pkt->stream_index = stream_id;
876  if (stc->last_flags & FLAG_KEY)
877  pkt->flags |= AV_PKT_FLAG_KEY;
878  pkt->pts = pts;
879 
880  return 0;
881 }
882 
884 {
885  NUTContext *nut = s->priv_data;
886  AVIOContext *bc = s->pb;
887  int i, frame_code = 0, ret, skip;
888  int64_t ts, back_ptr;
889 
890  for (;;) {
891  int64_t pos = avio_tell(bc);
892  uint64_t tmp = nut->next_startcode;
893  nut->next_startcode = 0;
894 
895  if (tmp) {
896  pos -= 8;
897  } else {
898  frame_code = avio_r8(bc);
899  if (url_feof(bc))
900  return AVERROR_EOF;
901  if (frame_code == 'N') {
902  tmp = frame_code;
903  for (i = 1; i < 8; i++)
904  tmp = (tmp << 8) + avio_r8(bc);
905  }
906  }
907  switch (tmp) {
908  case MAIN_STARTCODE:
909  case STREAM_STARTCODE:
910  case INDEX_STARTCODE:
911  skip = get_packetheader(nut, bc, 0, tmp);
912  avio_skip(bc, skip);
913  break;
914  case INFO_STARTCODE:
915  if (decode_info_header(nut) < 0)
916  goto resync;
917  break;
918  case SYNCPOINT_STARTCODE:
919  if (decode_syncpoint(nut, &ts, &back_ptr) < 0)
920  goto resync;
921  frame_code = avio_r8(bc);
922  case 0:
923  ret = decode_frame(nut, pkt, frame_code);
924  if (ret == 0)
925  return 0;
926  else if (ret == 1) // OK but discard packet
927  break;
928  default:
929 resync:
930  av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
931  tmp = find_any_startcode(bc, nut->last_syncpoint_pos + 1);
932  if (tmp == 0)
933  return AVERROR_INVALIDDATA;
934  av_log(s, AV_LOG_DEBUG, "sync\n");
935  nut->next_startcode = tmp;
936  }
937  }
938 }
939 
940 static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index,
941  int64_t *pos_arg, int64_t pos_limit)
942 {
943  NUTContext *nut = s->priv_data;
944  AVIOContext *bc = s->pb;
945  int64_t pos, pts, back_ptr;
946  av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n",
947  stream_index, *pos_arg, pos_limit);
948 
949  pos = *pos_arg;
950  do {
951  pos = find_startcode(bc, SYNCPOINT_STARTCODE, pos) + 1;
952  if (pos < 1) {
953  av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
954  return AV_NOPTS_VALUE;
955  }
956  } while (decode_syncpoint(nut, &pts, &back_ptr) < 0);
957  *pos_arg = pos - 1;
958  av_assert0(nut->last_syncpoint_pos == *pos_arg);
959 
960  av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts, back_ptr);
961  if (stream_index == -2)
962  return back_ptr;
963  av_assert0(stream_index == -1);
964  return pts;
965 }
966 
967 static int read_seek(AVFormatContext *s, int stream_index,
968  int64_t pts, int flags)
969 {
970  NUTContext *nut = s->priv_data;
971  AVStream *st = s->streams[stream_index];
972  Syncpoint dummy = { .ts = pts * av_q2d(st->time_base) * AV_TIME_BASE };
973  Syncpoint nopts_sp = { .ts = AV_NOPTS_VALUE, .back_ptr = AV_NOPTS_VALUE };
974  Syncpoint *sp, *next_node[2] = { &nopts_sp, &nopts_sp };
975  int64_t pos, pos2, ts;
976  int i;
977 
978  if (st->index_entries) {
979  int index = av_index_search_timestamp(st, pts, flags);
980  if (index < 0)
981  index = av_index_search_timestamp(st, pts, flags ^ AVSEEK_FLAG_BACKWARD);
982  if (index < 0)
983  return -1;
984 
985  pos2 = st->index_entries[index].pos;
986  ts = st->index_entries[index].timestamp;
987  } else {
988  av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pts_cmp,
989  (void **) next_node);
990  av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n",
991  next_node[0]->pos, next_node[1]->pos, next_node[0]->ts,
992  next_node[1]->ts);
993  pos = ff_gen_search(s, -1, dummy.ts, next_node[0]->pos,
994  next_node[1]->pos, next_node[1]->pos,
995  next_node[0]->ts, next_node[1]->ts,
997 
998  if (!(flags & AVSEEK_FLAG_BACKWARD)) {
999  dummy.pos = pos + 16;
1000  next_node[1] = &nopts_sp;
1001  av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
1002  (void **) next_node);
1003  pos2 = ff_gen_search(s, -2, dummy.pos, next_node[0]->pos,
1004  next_node[1]->pos, next_node[1]->pos,
1005  next_node[0]->back_ptr, next_node[1]->back_ptr,
1006  flags, &ts, nut_read_timestamp);
1007  if (pos2 >= 0)
1008  pos = pos2;
1009  // FIXME dir but I think it does not matter
1010  }
1011  dummy.pos = pos;
1012  sp = av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
1013  NULL);
1014 
1015  av_assert0(sp);
1016  pos2 = sp->back_ptr - 15;
1017  }
1018  av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
1019  pos = find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
1020  avio_seek(s->pb, pos, SEEK_SET);
1021  av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
1022  if (pos2 > pos || pos2 + 15 < pos)
1023  av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
1024  for (i = 0; i < s->nb_streams; i++)
1025  nut->stream[i].skip_until_key_frame = 1;
1026 
1027  return 0;
1028 }
1029 
1031 {
1032  NUTContext *nut = s->priv_data;
1033  int i;
1034 
1035  av_freep(&nut->time_base);
1036  av_freep(&nut->stream);
1037  ff_nut_free_sp(nut);
1038  for (i = 1; i < nut->header_count; i++)
1039  av_freep(&nut->header[i]);
1040 
1041  return 0;
1042 }
1043 
1045  .name = "nut",
1046  .long_name = NULL_IF_CONFIG_SMALL("NUT"),
1047  .flags = AVFMT_SEEK_TO_PTS,
1048  .priv_data_size = sizeof(NUTContext),
1049  .read_probe = nut_probe,
1053  .read_seek = read_seek,
1054  .extensions = "nut",
1055  .codec_tag = ff_nut_codec_tags,
1056 };