FFmpeg: libavformat/wtvdec.c Source File

FFmpeg
wtvdec.c
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1 /*
2  * Windows Television (WTV) demuxer
3  * Copyright (c) 2010-2011 Peter Ross <pross@xvid.org>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Windows Television (WTV) demuxer
25  * @author Peter Ross <pross@xvid.org>
26  */
27 
28 #include <inttypes.h>
29 
30 #include "libavutil/channel_layout.h"
31 #include "libavutil/intreadwrite.h"
32 #include "libavutil/intfloat.h"
33 #include "avformat.h"
34 #include "internal.h"
35 #include "wtv.h"
36 #include "mpegts.h"
37 
38 /* Macros for formating GUIDs */
39  #define PRI_PRETTY_GUID \
40  "%08"PRIx32"-%04"PRIx16"-%04"PRIx16"-%02x%02x%02x%02x%02x%02x%02x%02x"
41  #define ARG_PRETTY_GUID(g) \
42  AV_RL32(g),AV_RL16(g+4),AV_RL16(g+6),g[8],g[9],g[10],g[11],g[12],g[13],g[14],g[15]
43  #define LEN_PRETTY_GUID 34
44 
45 /*
46  *
47  * File system routines
48  *
49  */
50 
51  typedef struct {
52   AVIOContext *pb_filesystem; /**< file system (AVFormatContext->pb) */
53 
54   int sector_bits; /**< sector shift bits; used to convert sector number into pb_filesystem offset */
55   uint32_t *sectors; /**< file allocation table */
56   int nb_sectors; /**< number of sectors */
57 
58   int error;
59   int64_t position;
60   int64_t length;
61 } WtvFile;
62 
63  static int64_t seek_by_sector(AVIOContext *pb, int64_t sector, int64_t offset)
64 {
65  return avio_seek(pb, (sector << WTV_SECTOR_BITS) + offset, SEEK_SET);
66 }
67 
68 /**
69  * @return bytes read, 0 on end of file, or <0 on error
70  */
71  static int wtvfile_read_packet(void *opaque, uint8_t *buf, int buf_size)
72 {
73  WtvFile *wf = opaque;
74  AVIOContext *pb = wf->pb_filesystem;
75  int nread = 0;
76 
77  if (wf->error || pb->error)
78  return -1;
79  if (wf->position >= wf->length || url_feof(pb))
80  return 0;
81 
82  buf_size = FFMIN(buf_size, wf->length - wf->position);
83  while(nread < buf_size) {
84  int n;
85  int remaining_in_sector = (1 << wf->sector_bits) - (wf->position & ((1 << wf->sector_bits) - 1));
86  int read_request = FFMIN(buf_size - nread, remaining_in_sector);
87 
88  n = avio_read(pb, buf, read_request);
89  if (n <= 0)
90  break;
91  nread += n;
92  buf += n;
93  wf->position += n;
94  if (n == remaining_in_sector) {
95  int i = wf->position >> wf->sector_bits;
96  if (i >= wf->nb_sectors ||
97  (wf->sectors[i] != wf->sectors[i - 1] + (1 << (wf->sector_bits - WTV_SECTOR_BITS)) &&
98  seek_by_sector(pb, wf->sectors[i], 0) < 0)) {
99  wf->error = 1;
100  break;
101  }
102  }
103  }
104  return nread;
105 }
106 
107 /**
108  * @return position (or file length)
109  */
110  static int64_t wtvfile_seek(void *opaque, int64_t offset, int whence)
111 {
112  WtvFile *wf = opaque;
113  AVIOContext *pb = wf->pb_filesystem;
114 
115  if (whence == AVSEEK_SIZE)
116  return wf->length;
117  else if (whence == SEEK_CUR)
118  offset = wf->position + offset;
119  else if (whence == SEEK_END)
120  offset = wf->length;
121 
122  wf->error = offset < 0 || offset >= wf->length ||
123  seek_by_sector(pb, wf->sectors[offset >> wf->sector_bits],
124  offset & ((1 << wf->sector_bits) - 1)) < 0;
125  wf->position = offset;
126  return offset;
127 }
128 
129 /**
130  * read non-zero integers (le32) from input stream
131  * @param pb
132  * @param[out] data destination
133  * @param count maximum number of integers to read
134  * @return total number of integers read
135  */
136  static int read_ints(AVIOContext *pb, uint32_t *data, int count)
137 {
138  int i, total = 0;
139  for (i = 0; i < count; i++) {
140  if ((data[total] = avio_rl32(pb)))
141  total++;
142  }
143  return total;
144 }
145 
146 /**
147  * Open file
148  * @param first_sector First sector
149  * @param length Length of file (bytes)
150  * @param depth File allocation table depth
151  * @return NULL on error
152  */
153  static AVIOContext * wtvfile_open_sector(int first_sector, uint64_t length, int depth, AVFormatContext *s)
154 {
155  AVIOContext *pb;
156  WtvFile *wf;
157  uint8_t *buffer;
158  int64_t size;
159 
160  if (seek_by_sector(s->pb, first_sector, 0) < 0)
161  return NULL;
162 
163  wf = av_mallocz(sizeof(WtvFile));
164  if (!wf)
165  return NULL;
166 
167  if (depth == 0) {
168  wf->sectors = av_malloc(sizeof(uint32_t));
169  if (!wf->sectors) {
170  av_free(wf);
171  return NULL;
172  }
173  wf->sectors[0] = first_sector;
174  wf->nb_sectors = 1;
175  } else if (depth == 1) {
176  wf->sectors = av_malloc(WTV_SECTOR_SIZE);
177  if (!wf->sectors) {
178  av_free(wf);
179  return NULL;
180  }
181  wf->nb_sectors = read_ints(s->pb, wf->sectors, WTV_SECTOR_SIZE / 4);
182  } else if (depth == 2) {
183  uint32_t sectors1[WTV_SECTOR_SIZE / 4];
184  int nb_sectors1 = read_ints(s->pb, sectors1, WTV_SECTOR_SIZE / 4);
185  int i;
186 
187  wf->sectors = av_malloc_array(nb_sectors1, 1 << WTV_SECTOR_BITS);
188  if (!wf->sectors) {
189  av_free(wf);
190  return NULL;
191  }
192  wf->nb_sectors = 0;
193  for (i = 0; i < nb_sectors1; i++) {
194  if (seek_by_sector(s->pb, sectors1[i], 0) < 0)
195  break;
196  wf->nb_sectors += read_ints(s->pb, wf->sectors + i * WTV_SECTOR_SIZE / 4, WTV_SECTOR_SIZE / 4);
197  }
198  } else {
199  av_log(s, AV_LOG_ERROR, "unsupported file allocation table depth (0x%x)\n", depth);
200  av_free(wf);
201  return NULL;
202  }
203  wf->sector_bits = length & (1ULL<<63) ? WTV_SECTOR_BITS : WTV_BIGSECTOR_BITS;
204 
205  if (!wf->nb_sectors) {
206  av_free(wf->sectors);
207  av_free(wf);
208  return NULL;
209  }
210 
211  size = avio_size(s->pb);
212  if (size >= 0 && (int64_t)wf->sectors[wf->nb_sectors - 1] << WTV_SECTOR_BITS > size)
213  av_log(s, AV_LOG_WARNING, "truncated file\n");
214 
215  /* check length */
216  length &= 0xFFFFFFFFFFFF;
217  if (length > ((int64_t)wf->nb_sectors << wf->sector_bits)) {
218  av_log(s, AV_LOG_WARNING, "reported file length (0x%"PRIx64") exceeds number of available sectors (0x%"PRIx64")\n", length, (int64_t)wf->nb_sectors << wf->sector_bits);
219  length = (int64_t)wf->nb_sectors << wf->sector_bits;
220  }
221  wf->length = length;
222 
223  /* seek to initial sector */
224  wf->position = 0;
225  if (seek_by_sector(s->pb, wf->sectors[0], 0) < 0) {
226  av_free(wf->sectors);
227  av_free(wf);
228  return NULL;
229  }
230 
231  wf->pb_filesystem = s->pb;
232  buffer = av_malloc(1 << wf->sector_bits);
233  if (!buffer) {
234  av_free(wf->sectors);
235  av_free(wf);
236  return NULL;
237  }
238 
239  pb = avio_alloc_context(buffer, 1 << wf->sector_bits, 0, wf,
240  wtvfile_read_packet, NULL, wtvfile_seek);
241  if (!pb) {
242  av_free(buffer);
243  av_free(wf->sectors);
244  av_free(wf);
245  }
246  return pb;
247 }
248 
249 /**
250  * Open file using filename
251  * @param[in] buf directory buffer
252  * @param buf_size directory buffer size
253  * @param[in] filename
254  * @param filename_size size of filename
255  * @return NULL on error
256  */
257  static AVIOContext * wtvfile_open2(AVFormatContext *s, const uint8_t *buf, int buf_size, const uint8_t *filename, int filename_size)
258 {
259  const uint8_t *buf_end = buf + buf_size;
260 
261  while(buf + 48 <= buf_end) {
262  int dir_length, name_size, first_sector, depth;
263  uint64_t file_length;
264  const uint8_t *name;
265  if (ff_guidcmp(buf, ff_dir_entry_guid)) {
266  av_log(s, AV_LOG_ERROR, "unknown guid "FF_PRI_GUID ", expected dir_entry_guid; "
267  "remaining directory entries ignored\n", FF_ARG_GUID(buf));
268  break;
269  }
270  dir_length = AV_RL16(buf + 16);
271  file_length = AV_RL64(buf + 24);
272  name_size = 2 * AV_RL32(buf + 32);
273  if (name_size < 0) {
274  av_log(s, AV_LOG_ERROR,
275  "bad filename length, remaining directory entries ignored\n");
276  break;
277  }
278  if (48 + (int64_t)name_size > buf_end - buf) {
279  av_log(s, AV_LOG_ERROR, "filename exceeds buffer size; remaining directory entries ignored\n");
280  break;
281  }
282  first_sector = AV_RL32(buf + 40 + name_size);
283  depth = AV_RL32(buf + 44 + name_size);
284 
285  /* compare file name; test optional null terminator */
286  name = buf + 40;
287  if (name_size >= filename_size &&
288  !memcmp(name, filename, filename_size) &&
289  (name_size < filename_size + 2 || !AV_RN16(name + filename_size)))
290  return wtvfile_open_sector(first_sector, file_length, depth, s);
291 
292  buf += dir_length;
293  }
294  return 0;
295 }
296 
297  #define wtvfile_open(s, buf, buf_size, filename) \
298  wtvfile_open2(s, buf, buf_size, filename, sizeof(filename))
299 
300 /**
301  * Close file opened with wtvfile_open_sector(), or wtv_open()
302  */
303  static void wtvfile_close(AVIOContext *pb)
304 {
305  WtvFile *wf = pb->opaque;
306  av_free(wf->sectors);
307  av_freep(&pb->opaque);
308  av_freep(&pb->buffer);
309  av_free(pb);
310 }
311 
312 /*
313  *
314  * Main demuxer
315  *
316  */
317 
318  typedef struct {
319   int seen_data;
320 } WtvStream;
321 
322  typedef struct {
323   AVIOContext *pb; /**< timeline file */
324   int64_t epoch;
325   int64_t pts; /**< pts for next data chunk */
326   int64_t last_valid_pts; /**< latest valid pts, used for interative seeking */
327 
328  /* maintain private seek index, as the AVIndexEntry->pos is relative to the
329  start of the 'timeline' file, not the file system (AVFormatContext->pb) */
330   AVIndexEntry *index_entries;
331   int nb_index_entries;
332   unsigned int index_entries_allocated_size;
333 } WtvContext;
334 
335 /* WTV GUIDs */
336  static const ff_asf_guid EVENTID_SubtitleSpanningEvent =
337  {0x48,0xC0,0xCE,0x5D,0xB9,0xD0,0x63,0x41,0x87,0x2C,0x4F,0x32,0x22,0x3B,0xE8,0x8A};
338  static const ff_asf_guid EVENTID_LanguageSpanningEvent =
339  {0x6D,0x66,0x92,0xE2,0x02,0x9C,0x8D,0x44,0xAA,0x8D,0x78,0x1A,0x93,0xFD,0xC3,0x95};
340  static const ff_asf_guid EVENTID_AudioDescriptorSpanningEvent =
341  {0x1C,0xD4,0x7B,0x10,0xDA,0xA6,0x91,0x46,0x83,0x69,0x11,0xB2,0xCD,0xAA,0x28,0x8E};
342  static const ff_asf_guid EVENTID_CtxADescriptorSpanningEvent =
343  {0xE6,0xA2,0xB4,0x3A,0x47,0x42,0x34,0x4B,0x89,0x6C,0x30,0xAF,0xA5,0xD2,0x1C,0x24};
344  static const ff_asf_guid EVENTID_CSDescriptorSpanningEvent =
345  {0xD9,0x79,0xE7,0xEf,0xF0,0x97,0x86,0x47,0x80,0x0D,0x95,0xCF,0x50,0x5D,0xDC,0x66};
346  static const ff_asf_guid EVENTID_DVBScramblingControlSpanningEvent =
347  {0xC4,0xE1,0xD4,0x4B,0xA1,0x90,0x09,0x41,0x82,0x36,0x27,0xF0,0x0E,0x7D,0xCC,0x5B};
348  static const ff_asf_guid EVENTID_StreamIDSpanningEvent =
349  {0x68,0xAB,0xF1,0xCA,0x53,0xE1,0x41,0x4D,0xA6,0xB3,0xA7,0xC9,0x98,0xDB,0x75,0xEE};
350  static const ff_asf_guid EVENTID_TeletextSpanningEvent =
351  {0x50,0xD9,0x99,0x95,0x33,0x5F,0x17,0x46,0xAF,0x7C,0x1E,0x54,0xB5,0x10,0xDA,0xA3};
352  static const ff_asf_guid EVENTID_AudioTypeSpanningEvent =
353  {0xBE,0xBF,0x1C,0x50,0x49,0xB8,0xCE,0x42,0x9B,0xE9,0x3D,0xB8,0x69,0xFB,0x82,0xB3};
354 
355 /* Windows media GUIDs */
356 
357 /* Media types */
358  static const ff_asf_guid mediasubtype_mpeg1payload =
359  {0x81,0xEB,0x36,0xE4,0x4F,0x52,0xCE,0x11,0x9F,0x53,0x00,0x20,0xAF,0x0B,0xA7,0x70};
360  static const ff_asf_guid mediatype_mpeg2_sections =
361  {0x6C,0x17,0x5F,0x45,0x06,0x4B,0xCE,0x47,0x9A,0xEF,0x8C,0xAE,0xF7,0x3D,0xF7,0xB5};
362  static const ff_asf_guid mediatype_mpeg2_pes =
363  {0x20,0x80,0x6D,0xE0,0x46,0xDB,0xCF,0x11,0xB4,0xD1,0x00,0x80,0x5F,0x6C,0xBB,0xEA};
364  static const ff_asf_guid mediatype_mstvcaption =
365  {0x89,0x8A,0x8B,0xB8,0x49,0xB0,0x80,0x4C,0xAD,0xCF,0x58,0x98,0x98,0x5E,0x22,0xC1};
366 
367 /* Media subtypes */
368  static const ff_asf_guid mediasubtype_dvb_subtitle =
369  {0xC3,0xCB,0xFF,0x34,0xB3,0xD5,0x71,0x41,0x90,0x02,0xD4,0xC6,0x03,0x01,0x69,0x7F};
370  static const ff_asf_guid mediasubtype_teletext =
371  {0xE3,0x76,0x2A,0xF7,0x0A,0xEB,0xD0,0x11,0xAC,0xE4,0x00,0x00,0xC0,0xCC,0x16,0xBA};
372  static const ff_asf_guid mediasubtype_dtvccdata =
373  {0xAA,0xDD,0x2A,0xF5,0xF0,0x36,0xF5,0x43,0x95,0xEA,0x6D,0x86,0x64,0x84,0x26,0x2A};
374  static const ff_asf_guid mediasubtype_mpeg2_sections =
375  {0x79,0x85,0x9F,0x4A,0xF8,0x6B,0x92,0x43,0x8A,0x6D,0xD2,0xDD,0x09,0xFA,0x78,0x61};
376 
377  static int read_probe(AVProbeData *p)
378 {
379  return ff_guidcmp(p->buf, ff_wtv_guid) ? 0 : AVPROBE_SCORE_MAX;
380 }
381 
382 /**
383  * Convert win32 FILETIME to ISO-8601 string
384  * @return <0 on error
385  */
386  static int filetime_to_iso8601(char *buf, int buf_size, int64_t value)
387 {
388  time_t t = (value / 10000000LL) - 11644473600LL;
389  struct tm *tm = gmtime(&t);
390  if (!tm)
391  return -1;
392  strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
393  return 0;
394 }
395 
396 /**
397  * Convert crazy time (100ns since 1 Jan 0001) to ISO-8601 string
398  * @return <0 on error
399  */
400  static int crazytime_to_iso8601(char *buf, int buf_size, int64_t value)
401 {
402  time_t t = (value / 10000000LL) - 719162LL*86400LL;
403  struct tm *tm = gmtime(&t);
404  if (!tm)
405  return -1;
406  strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
407  return 0;
408 }
409 
410 /**
411  * Convert OLE DATE to ISO-8601 string
412  * @return <0 on error
413  */
414  static int oledate_to_iso8601(char *buf, int buf_size, int64_t value)
415 {
416  time_t t = (av_int2double(value) - 25569.0) * 86400;
417  struct tm *result= gmtime(&t);
418  if (!result)
419  return -1;
420  strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", result);
421  return 0;
422 }
423 
424  static void get_attachment(AVFormatContext *s, AVIOContext *pb, int length)
425 {
426  char mime[1024];
427  char description[1024];
428  unsigned int filesize;
429  AVStream *st;
430  int ret;
431  int64_t pos = avio_tell(pb);
432 
433  avio_get_str16le(pb, INT_MAX, mime, sizeof(mime));
434  if (strcmp(mime, "image/jpeg"))
435  goto done;
436 
437  avio_r8(pb);
438  avio_get_str16le(pb, INT_MAX, description, sizeof(description));
439  filesize = avio_rl32(pb);
440  if (!filesize)
441  goto done;
442 
443  st = avformat_new_stream(s, NULL);
444  if (!st)
445  goto done;
446  av_dict_set(&st->metadata, "title", description, 0);
447  st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
448  st->codec->codec_id = AV_CODEC_ID_MJPEG;
449  st->id = -1;
450  ret = av_get_packet(pb, &st->attached_pic, filesize);
451  if (ret < 0)
452  goto done;
453  st->attached_pic.stream_index = st->index;
454  st->attached_pic.flags |= AV_PKT_FLAG_KEY;
455  st->disposition |= AV_DISPOSITION_ATTACHED_PIC;
456 done:
457  avio_seek(pb, pos + length, SEEK_SET);
458 }
459 
460  static void get_tag(AVFormatContext *s, AVIOContext *pb, const char *key, int type, int length)
461 {
462  int buf_size;
463  char *buf;
464 
465  if (!strcmp(key, "WM/MediaThumbType")) {
466  avio_skip(pb, length);
467  return;
468  }
469 
470  buf_size = FFMAX(2*length, LEN_PRETTY_GUID) + 1;
471  buf = av_malloc(buf_size);
472  if (!buf)
473  return;
474 
475  if (type == 0 && length == 4) {
476  snprintf(buf, buf_size, "%u", avio_rl32(pb));
477  } else if (type == 1) {
478  avio_get_str16le(pb, length, buf, buf_size);
479  if (!strlen(buf)) {
480  av_free(buf);
481  return;
482  }
483  } else if (type == 3 && length == 4) {
484  strcpy(buf, avio_rl32(pb) ? "true" : "false");
485  } else if (type == 4 && length == 8) {
486  int64_t num = avio_rl64(pb);
487  if (!strcmp(key, "WM/EncodingTime") ||
488  !strcmp(key, "WM/MediaOriginalBroadcastDateTime")) {
489  if (filetime_to_iso8601(buf, buf_size, num) < 0) {
490  av_free(buf);
491  return;
492  }
493  } else if (!strcmp(key, "WM/WMRVEncodeTime") ||
494  !strcmp(key, "WM/WMRVEndTime")) {
495  if (crazytime_to_iso8601(buf, buf_size, num) < 0) {
496  av_free(buf);
497  return;
498  }
499  } else if (!strcmp(key, "WM/WMRVExpirationDate")) {
500  if (oledate_to_iso8601(buf, buf_size, num) < 0 ) {
501  av_free(buf);
502  return;
503  }
504  } else if (!strcmp(key, "WM/WMRVBitrate"))
505  snprintf(buf, buf_size, "%f", av_int2double(num));
506  else
507  snprintf(buf, buf_size, "%"PRIi64, num);
508  } else if (type == 5 && length == 2) {
509  snprintf(buf, buf_size, "%u", avio_rl16(pb));
510  } else if (type == 6 && length == 16) {
511  ff_asf_guid guid;
512  avio_read(pb, guid, 16);
513  snprintf(buf, buf_size, PRI_PRETTY_GUID, ARG_PRETTY_GUID(guid));
514  } else if (type == 2 && !strcmp(key, "WM/Picture")) {
515  get_attachment(s, pb, length);
516  av_freep(&buf);
517  return;
518  } else {
519  av_freep(&buf);
520  av_log(s, AV_LOG_WARNING, "unsupported metadata entry; key:%s, type:%d, length:0x%x\n", key, type, length);
521  avio_skip(pb, length);
522  return;
523  }
524 
525  av_dict_set(&s->metadata, key, buf, 0);
526  av_freep(&buf);
527 }
528 
529 /**
530  * Parse metadata entries
531  */
532  static void parse_legacy_attrib(AVFormatContext *s, AVIOContext *pb)
533 {
534  ff_asf_guid guid;
535  int length, type;
536  while(!url_feof(pb)) {
537  char key[1024];
538  ff_get_guid(pb, &guid);
539  type = avio_rl32(pb);
540  length = avio_rl32(pb);
541  if (!length)
542  break;
543  if (ff_guidcmp(&guid, ff_metadata_guid)) {
544  av_log(s, AV_LOG_WARNING, "unknown guid "FF_PRI_GUID ", expected metadata_guid; "
545  "remaining metadata entries ignored\n", FF_ARG_GUID(guid));
546  break;
547  }
548  avio_get_str16le(pb, INT_MAX, key, sizeof(key));
549  get_tag(s, pb, key, type, length);
550  }
551 
552  ff_metadata_conv(&s->metadata, NULL, ff_asf_metadata_conv);
553 }
554 
555 /**
556  * parse VIDEOINFOHEADER2 structure
557  * @return bytes consumed
558  */
559  static int parse_videoinfoheader2(AVFormatContext *s, AVStream *st)
560 {
561  WtvContext *wtv = s->priv_data;
562  AVIOContext *pb = wtv->pb;
563 
564  avio_skip(pb, 72); // picture aspect ratio is unreliable
565  st->codec->codec_tag = ff_get_bmp_header(pb, st, NULL);
566 
567  return 72 + 40;
568 }
569 
570 /**
571  * Parse MPEG1WAVEFORMATEX extradata structure
572  */
573  static void parse_mpeg1waveformatex(AVStream *st)
574 {
575  /* fwHeadLayer */
576  switch (AV_RL16(st->codec->extradata)) {
577  case 0x0001 : st->codec->codec_id = AV_CODEC_ID_MP1; break;
578  case 0x0002 : st->codec->codec_id = AV_CODEC_ID_MP2; break;
579  case 0x0004 : st->codec->codec_id = AV_CODEC_ID_MP3; break;
580  }
581 
582  st->codec->bit_rate = AV_RL32(st->codec->extradata + 2); /* dwHeadBitrate */
583 
584  /* dwHeadMode */
585  switch (AV_RL16(st->codec->extradata + 6)) {
586  case 1 :
587  case 2 :
588  case 4 : st->codec->channels = 2;
589  st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
590  break;
591  case 8 : st->codec->channels = 1;
592  st->codec->channel_layout = AV_CH_LAYOUT_MONO;
593  break;
594  }
595 }
596 
597 /**
598  * Initialise stream
599  * @param st Stream to initialise, or NULL to create and initialise new stream
600  * @return NULL on error
601  */
602  static AVStream * new_stream(AVFormatContext *s, AVStream *st, int sid, int codec_type)
603 {
604  if (st) {
605  if (st->codec->extradata) {
606  av_freep(&st->codec->extradata);
607  st->codec->extradata_size = 0;
608  }
609  } else {
610  WtvStream *wst = av_mallocz(sizeof(WtvStream));
611  if (!wst)
612  return NULL;
613  st = avformat_new_stream(s, NULL);
614  if (!st) {
615  av_free(wst);
616  return NULL;
617  }
618  st->id = sid;
619  st->priv_data = wst;
620  }
621  st->codec->codec_type = codec_type;
622  st->need_parsing = AVSTREAM_PARSE_FULL;
623  avpriv_set_pts_info(st, 64, 1, 10000000);
624  return st;
625 }
626 
627 /**
628  * parse Media Type structure and populate stream
629  * @param st Stream, or NULL to create new stream
630  * @param mediatype Mediatype GUID
631  * @param subtype Subtype GUID
632  * @param formattype Format GUID
633  * @param size Size of format buffer
634  * @return NULL on error
635  */
636  static AVStream * parse_media_type(AVFormatContext *s, AVStream *st, int sid,
637  ff_asf_guid mediatype, ff_asf_guid subtype,
638  ff_asf_guid formattype, uint64_t size)
639 {
640  WtvContext *wtv = s->priv_data;
641  AVIOContext *pb = wtv->pb;
642  if (!ff_guidcmp(subtype, ff_mediasubtype_cpfilters_processed) &&
643  !ff_guidcmp(formattype, ff_format_cpfilters_processed)) {
644  ff_asf_guid actual_subtype;
645  ff_asf_guid actual_formattype;
646 
647  if (size < 32) {
648  av_log(s, AV_LOG_WARNING, "format buffer size underflow\n");
649  avio_skip(pb, size);
650  return NULL;
651  }
652 
653  avio_skip(pb, size - 32);
654  ff_get_guid(pb, &actual_subtype);
655  ff_get_guid(pb, &actual_formattype);
656  avio_seek(pb, -size, SEEK_CUR);
657 
658  st = parse_media_type(s, st, sid, mediatype, actual_subtype, actual_formattype, size - 32);
659  avio_skip(pb, 32);
660  return st;
661  } else if (!ff_guidcmp(mediatype, ff_mediatype_audio)) {
662  st = new_stream(s, st, sid, AVMEDIA_TYPE_AUDIO);
663  if (!st)
664  return NULL;
665  if (!ff_guidcmp(formattype, ff_format_waveformatex)) {
666  int ret = ff_get_wav_header(pb, st->codec, size);
667  if (ret < 0)
668  return NULL;
669  } else {
670  if (ff_guidcmp(formattype, ff_format_none))
671  av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID "\n", FF_ARG_GUID(formattype));
672  avio_skip(pb, size);
673  }
674 
675  if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {
676  st->codec->codec_id = ff_wav_codec_get_id(AV_RL32(subtype), st->codec->bits_per_coded_sample);
677  } else if (!ff_guidcmp(subtype, mediasubtype_mpeg1payload)) {
678  if (st->codec->extradata && st->codec->extradata_size >= 22)
679  parse_mpeg1waveformatex(st);
680  else
681  av_log(s, AV_LOG_WARNING, "MPEG1WAVEFORMATEX underflow\n");
682  } else {
683  st->codec->codec_id = ff_codec_guid_get_id(ff_codec_wav_guids, subtype);
684  if (st->codec->codec_id == AV_CODEC_ID_NONE)
685  av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID "\n", FF_ARG_GUID(subtype));
686  }
687  return st;
688  } else if (!ff_guidcmp(mediatype, ff_mediatype_video)) {
689  st = new_stream(s, st, sid, AVMEDIA_TYPE_VIDEO);
690  if (!st)
691  return NULL;
692  if (!ff_guidcmp(formattype, ff_format_videoinfo2)) {
693  int consumed = parse_videoinfoheader2(s, st);
694  avio_skip(pb, FFMAX(size - consumed, 0));
695  } else if (!ff_guidcmp(formattype, ff_format_mpeg2_video)) {
696  uint64_t consumed = parse_videoinfoheader2(s, st);
697  /* ignore extradata; files produced by windows media center contain meaningless mpeg1 sequence header */
698  avio_skip(pb, FFMAX(size - consumed, 0));
699  } else {
700  if (ff_guidcmp(formattype, ff_format_none))
701  av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID "\n", FF_ARG_GUID(formattype));
702  avio_skip(pb, size);
703  }
704 
705  if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {
706  st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, AV_RL32(subtype));
707  } else {
708  st->codec->codec_id = ff_codec_guid_get_id(ff_video_guids, subtype);
709  }
710  if (st->codec->codec_id == AV_CODEC_ID_NONE)
711  av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID "\n", FF_ARG_GUID(subtype));
712  return st;
713  } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_pes) &&
714  !ff_guidcmp(subtype, mediasubtype_dvb_subtitle)) {
715  st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);
716  if (!st)
717  return NULL;
718  if (ff_guidcmp(formattype, ff_format_none))
719  av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID "\n", FF_ARG_GUID(formattype));
720  avio_skip(pb, size);
721  st->codec->codec_id = AV_CODEC_ID_DVB_SUBTITLE;
722  return st;
723  } else if (!ff_guidcmp(mediatype, mediatype_mstvcaption) &&
724  (!ff_guidcmp(subtype, mediasubtype_teletext) || !ff_guidcmp(subtype, mediasubtype_dtvccdata))) {
725  st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);
726  if (!st)
727  return NULL;
728  if (ff_guidcmp(formattype, ff_format_none))
729  av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID "\n", FF_ARG_GUID(formattype));
730  avio_skip(pb, size);
731  st->codec->codec_id = !ff_guidcmp(subtype, mediasubtype_teletext) ? AV_CODEC_ID_DVB_TELETEXT : AV_CODEC_ID_EIA_608;
732  return st;
733  } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_sections) &&
734  !ff_guidcmp(subtype, mediasubtype_mpeg2_sections)) {
735  if (ff_guidcmp(formattype, ff_format_none))
736  av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID "\n", FF_ARG_GUID(formattype));
737  avio_skip(pb, size);
738  return NULL;
739  }
740 
741  av_log(s, AV_LOG_WARNING, "unknown media type, mediatype:"FF_PRI_GUID
742  ", subtype:"FF_PRI_GUID ", formattype:"FF_PRI_GUID "\n",
743  FF_ARG_GUID(mediatype), FF_ARG_GUID(subtype), FF_ARG_GUID(formattype));
744  avio_skip(pb, size);
745  return NULL;
746 }
747 
748 enum {
749   SEEK_TO_DATA = 0,
750   SEEK_TO_PTS,
751 };
752 
753 /**
754  * Parse WTV chunks
755  * @param mode SEEK_TO_DATA or SEEK_TO_PTS
756  * @param seekts timestamp
757  * @param[out] len_ptr Length of data chunk
758  * @return stream index of data chunk, or <0 on error
759  */
760  static int parse_chunks(AVFormatContext *s, int mode, int64_t seekts, int *len_ptr)
761 {
762  WtvContext *wtv = s->priv_data;
763  AVIOContext *pb = wtv->pb;
764  while (!url_feof(pb)) {
765  ff_asf_guid g;
766  int len, sid, consumed;
767 
768  ff_get_guid(pb, &g);
769  len = avio_rl32(pb);
770  if (len < 32)
771  break;
772  sid = avio_rl32(pb) & 0x7FFF;
773  avio_skip(pb, 8);
774  consumed = 32;
775 
776  if (!ff_guidcmp(g, ff_SBE2_STREAM_DESC_EVENT)) {
777  if (ff_find_stream_index(s, sid) < 0) {
778  ff_asf_guid mediatype, subtype, formattype;
779  int size;
780  avio_skip(pb, 28);
781  ff_get_guid(pb, &mediatype);
782  ff_get_guid(pb, &subtype);
783  avio_skip(pb, 12);
784  ff_get_guid(pb, &formattype);
785  size = avio_rl32(pb);
786  parse_media_type(s, 0, sid, mediatype, subtype, formattype, size);
787  consumed += 92 + size;
788  }
789  } else if (!ff_guidcmp(g, ff_stream2_guid)) {
790  int stream_index = ff_find_stream_index(s, sid);
791  if (stream_index >= 0 && s->streams[stream_index]->priv_data && !((WtvStream*)s->streams[stream_index]->priv_data)->seen_data) {
792  ff_asf_guid mediatype, subtype, formattype;
793  int size;
794  avio_skip(pb, 12);
795  ff_get_guid(pb, &mediatype);
796  ff_get_guid(pb, &subtype);
797  avio_skip(pb, 12);
798  ff_get_guid(pb, &formattype);
799  size = avio_rl32(pb);
800  parse_media_type(s, s->streams[stream_index], sid, mediatype, subtype, formattype, size);
801  consumed += 76 + size;
802  }
803  } else if (!ff_guidcmp(g, EVENTID_AudioDescriptorSpanningEvent) ||
804  !ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
805  !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent) ||
806  !ff_guidcmp(g, EVENTID_StreamIDSpanningEvent) ||
807  !ff_guidcmp(g, EVENTID_SubtitleSpanningEvent) ||
808  !ff_guidcmp(g, EVENTID_TeletextSpanningEvent)) {
809  int stream_index = ff_find_stream_index(s, sid);
810  if (stream_index >= 0) {
811  AVStream *st = s->streams[stream_index];
812  uint8_t buf[258];
813  const uint8_t *pbuf = buf;
814  int buf_size;
815 
816  avio_skip(pb, 8);
817  consumed += 8;
818  if (!ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
819  !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent)) {
820  avio_skip(pb, 6);
821  consumed += 6;
822  }
823 
824  buf_size = FFMIN(len - consumed, sizeof(buf));
825  avio_read(pb, buf, buf_size);
826  consumed += buf_size;
827  ff_parse_mpeg2_descriptor(s, st, 0, &pbuf, buf + buf_size, NULL, 0, 0, NULL);
828  }
829  } else if (!ff_guidcmp(g, EVENTID_AudioTypeSpanningEvent)) {
830  int stream_index = ff_find_stream_index(s, sid);
831  if (stream_index >= 0) {
832  AVStream *st = s->streams[stream_index];
833  int audio_type;
834  avio_skip(pb, 8);
835  audio_type = avio_r8(pb);
836  if (audio_type == 2)
837  st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
838  else if (audio_type == 3)
839  st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
840  consumed += 9;
841  }
842  } else if (!ff_guidcmp(g, EVENTID_DVBScramblingControlSpanningEvent)) {
843  int stream_index = ff_find_stream_index(s, sid);
844  if (stream_index >= 0) {
845  avio_skip(pb, 12);
846  if (avio_rl32(pb))
847  av_log(s, AV_LOG_WARNING, "DVB scrambled stream detected (st:%d), decoding will likely fail\n", stream_index);
848  consumed += 16;
849  }
850  } else if (!ff_guidcmp(g, EVENTID_LanguageSpanningEvent)) {
851  int stream_index = ff_find_stream_index(s, sid);
852  if (stream_index >= 0) {
853  AVStream *st = s->streams[stream_index];
854  uint8_t language[4];
855  avio_skip(pb, 12);
856  avio_read(pb, language, 3);
857  if (language[0]) {
858  language[3] = 0;
859  av_dict_set(&st->metadata, "language", language, 0);
860  if (!strcmp(language, "nar") || !strcmp(language, "NAR"))
861  st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
862  }
863  consumed += 15;
864  }
865  } else if (!ff_guidcmp(g, ff_timestamp_guid)) {
866  int stream_index = ff_find_stream_index(s, sid);
867  if (stream_index >= 0) {
868  avio_skip(pb, 8);
869  wtv->pts = avio_rl64(pb);
870  consumed += 16;
871  if (wtv->pts == -1)
872  wtv->pts = AV_NOPTS_VALUE;
873  else {
874  wtv->last_valid_pts = wtv->pts;
875  if (wtv->epoch == AV_NOPTS_VALUE || wtv->pts < wtv->epoch)
876  wtv->epoch = wtv->pts;
877  if (mode == SEEK_TO_PTS && wtv->pts >= seekts) {
878  avio_skip(pb, WTV_PAD8(len) - consumed);
879  return 0;
880  }
881  }
882  }
883  } else if (!ff_guidcmp(g, ff_data_guid)) {
884  int stream_index = ff_find_stream_index(s, sid);
885  if (mode == SEEK_TO_DATA && stream_index >= 0 && len > 32 && s->streams[stream_index]->priv_data) {
886  WtvStream *wst = s->streams[stream_index]->priv_data;
887  wst->seen_data = 1;
888  if (len_ptr) {
889  *len_ptr = len;
890  }
891  return stream_index;
892  }
893  } else if (!ff_guidcmp(g, /* DSATTRIB_WMDRMProtectionInfo */ (const ff_asf_guid){0x83,0x95,0x74,0x40,0x9D,0x6B,0xEC,0x4E,0xB4,0x3C,0x67,0xA1,0x80,0x1E,0x1A,0x9B})) {
894  int stream_index = ff_find_stream_index(s, sid);
895  if (stream_index >= 0)
896  av_log(s, AV_LOG_WARNING, "encrypted stream detected (st:%d), decoding will likely fail\n", stream_index);
897  } else if (
898  !ff_guidcmp(g, /* DSATTRIB_CAPTURE_STREAMTIME */ (const ff_asf_guid){0x14,0x56,0x1A,0x0C,0xCD,0x30,0x40,0x4F,0xBC,0xBF,0xD0,0x3E,0x52,0x30,0x62,0x07}) ||
899  !ff_guidcmp(g, /* DSATTRIB_PBDATAG_ATTRIBUTE */ (const ff_asf_guid){0x79,0x66,0xB5,0xE0,0xB9,0x12,0xCC,0x43,0xB7,0xDF,0x57,0x8C,0xAA,0x5A,0x7B,0x63}) ||
900  !ff_guidcmp(g, /* DSATTRIB_PicSampleSeq */ (const ff_asf_guid){0x02,0xAE,0x5B,0x2F,0x8F,0x7B,0x60,0x4F,0x82,0xD6,0xE4,0xEA,0x2F,0x1F,0x4C,0x99}) ||
901  !ff_guidcmp(g, /* DSATTRIB_TRANSPORT_PROPERTIES */ ff_DSATTRIB_TRANSPORT_PROPERTIES) ||
902  !ff_guidcmp(g, /* dvr_ms_vid_frame_rep_data */ (const ff_asf_guid){0xCC,0x32,0x64,0xDD,0x29,0xE2,0xDB,0x40,0x80,0xF6,0xD2,0x63,0x28,0xD2,0x76,0x1F}) ||
903  !ff_guidcmp(g, /* EVENTID_ChannelChangeSpanningEvent */ (const ff_asf_guid){0xE5,0xC5,0x67,0x90,0x5C,0x4C,0x05,0x42,0x86,0xC8,0x7A,0xFE,0x20,0xFE,0x1E,0xFA}) ||
904  !ff_guidcmp(g, /* EVENTID_ChannelInfoSpanningEvent */ (const ff_asf_guid){0x80,0x6D,0xF3,0x41,0x32,0x41,0xC2,0x4C,0xB1,0x21,0x01,0xA4,0x32,0x19,0xD8,0x1B}) ||
905  !ff_guidcmp(g, /* EVENTID_ChannelTypeSpanningEvent */ (const ff_asf_guid){0x51,0x1D,0xAB,0x72,0xD2,0x87,0x9B,0x48,0xBA,0x11,0x0E,0x08,0xDC,0x21,0x02,0x43}) ||
906  !ff_guidcmp(g, /* EVENTID_PIDListSpanningEvent */ (const ff_asf_guid){0x65,0x8F,0xFC,0x47,0xBB,0xE2,0x34,0x46,0x9C,0xEF,0xFD,0xBF,0xE6,0x26,0x1D,0x5C}) ||
907  !ff_guidcmp(g, /* EVENTID_SignalAndServiceStatusSpanningEvent */ (const ff_asf_guid){0xCB,0xC5,0x68,0x80,0x04,0x3C,0x2B,0x49,0xB4,0x7D,0x03,0x08,0x82,0x0D,0xCE,0x51}) ||
908  !ff_guidcmp(g, /* EVENTID_StreamTypeSpanningEvent */ (const ff_asf_guid){0xBC,0x2E,0xAF,0x82,0xA6,0x30,0x64,0x42,0xA8,0x0B,0xAD,0x2E,0x13,0x72,0xAC,0x60}) ||
909  !ff_guidcmp(g, (const ff_asf_guid){0x1E,0xBE,0xC3,0xC5,0x43,0x92,0xDC,0x11,0x85,0xE5,0x00,0x12,0x3F,0x6F,0x73,0xB9}) ||
910  !ff_guidcmp(g, (const ff_asf_guid){0x3B,0x86,0xA2,0xB1,0xEB,0x1E,0xC3,0x44,0x8C,0x88,0x1C,0xA3,0xFF,0xE3,0xE7,0x6A}) ||
911  !ff_guidcmp(g, (const ff_asf_guid){0x4E,0x7F,0x4C,0x5B,0xC4,0xD0,0x38,0x4B,0xA8,0x3E,0x21,0x7F,0x7B,0xBF,0x52,0xE7}) ||
912  !ff_guidcmp(g, (const ff_asf_guid){0x63,0x36,0xEB,0xFE,0xA1,0x7E,0xD9,0x11,0x83,0x08,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
913  !ff_guidcmp(g, (const ff_asf_guid){0x70,0xE9,0xF1,0xF8,0x89,0xA4,0x4C,0x4D,0x83,0x73,0xB8,0x12,0xE0,0xD5,0xF8,0x1E}) ||
914  !ff_guidcmp(g, ff_index_guid) ||
915  !ff_guidcmp(g, ff_sync_guid) ||
916  !ff_guidcmp(g, ff_stream1_guid) ||
917  !ff_guidcmp(g, (const ff_asf_guid){0xF7,0x10,0x02,0xB9,0xEE,0x7C,0xED,0x4E,0xBD,0x7F,0x05,0x40,0x35,0x86,0x18,0xA1})) {
918  //ignore known guids
919  } else
920  av_log(s, AV_LOG_WARNING, "unsupported chunk:"FF_PRI_GUID "\n", FF_ARG_GUID(g));
921 
922  avio_skip(pb, WTV_PAD8(len) - consumed);
923  }
924  return AVERROR_EOF;
925 }
926 
927  static int read_header(AVFormatContext *s)
928 {
929  WtvContext *wtv = s->priv_data;
930  int root_sector, root_size;
931  uint8_t root[WTV_SECTOR_SIZE];
932  AVIOContext *pb;
933  int64_t timeline_pos;
934  int ret;
935 
936  wtv->epoch =
937  wtv->pts =
938  wtv->last_valid_pts = AV_NOPTS_VALUE;
939 
940  /* read root directory sector */
941  avio_skip(s->pb, 0x30);
942  root_size = avio_rl32(s->pb);
943  if (root_size > sizeof(root)) {
944  av_log(s, AV_LOG_ERROR, "root directory size exceeds sector size\n");
945  return AVERROR_INVALIDDATA;
946  }
947  avio_skip(s->pb, 4);
948  root_sector = avio_rl32(s->pb);
949 
950  seek_by_sector(s->pb, root_sector, 0);
951  root_size = avio_read(s->pb, root, root_size);
952  if (root_size < 0)
953  return AVERROR_INVALIDDATA;
954 
955  /* parse chunks up until first data chunk */
956  wtv->pb = wtvfile_open(s, root, root_size, ff_timeline_le16);
957  if (!wtv->pb) {
958  av_log(s, AV_LOG_ERROR, "timeline data missing\n");
959  return AVERROR_INVALIDDATA;
960  }
961 
962  ret = parse_chunks(s, SEEK_TO_DATA, 0, 0);
963  if (ret < 0)
964  return ret;
965  avio_seek(wtv->pb, -32, SEEK_CUR);
966 
967  timeline_pos = avio_tell(s->pb); // save before opening another file
968 
969  /* read metadata */
970  pb = wtvfile_open(s, root, root_size, ff_table_0_entries_legacy_attrib_le16);
971  if (pb) {
972  parse_legacy_attrib(s, pb);
973  wtvfile_close(pb);
974  }
975 
976  /* read seek index */
977  if (s->nb_streams) {
978  AVStream *st = s->streams[0];
979  pb = wtvfile_open(s, root, root_size, ff_table_0_entries_time_le16);
980  if (pb) {
981  while(1) {
982  uint64_t timestamp = avio_rl64(pb);
983  uint64_t frame_nb = avio_rl64(pb);
984  if (url_feof(pb))
985  break;
986  ff_add_index_entry(&wtv->index_entries, &wtv->nb_index_entries, &wtv->index_entries_allocated_size,
987  0, timestamp, frame_nb, 0, AVINDEX_KEYFRAME);
988  }
989  wtvfile_close(pb);
990 
991  if (wtv->nb_index_entries) {
992  pb = wtvfile_open(s, root, root_size, ff_timeline_table_0_entries_Events_le16);
993  if (pb) {
994  int i;
995  while (1) {
996  uint64_t frame_nb = avio_rl64(pb);
997  uint64_t position = avio_rl64(pb);
998  if (url_feof(pb))
999  break;
1000  for (i = wtv->nb_index_entries - 1; i >= 0; i--) {
1001  AVIndexEntry *e = wtv->index_entries + i;
1002  if (frame_nb > e->size)
1003  break;
1004  if (position > e->pos)
1005  e->pos = position;
1006  }
1007  }
1008  wtvfile_close(pb);
1009  st->duration = wtv->index_entries[wtv->nb_index_entries - 1].timestamp;
1010  }
1011  }
1012  }
1013  }
1014 
1015  avio_seek(s->pb, timeline_pos, SEEK_SET);
1016  return 0;
1017 }
1018 
1019  static int read_packet(AVFormatContext *s, AVPacket *pkt)
1020 {
1021  WtvContext *wtv = s->priv_data;
1022  AVIOContext *pb = wtv->pb;
1023  int stream_index, len, ret;
1024 
1025  stream_index = parse_chunks(s, SEEK_TO_DATA, 0, &len);
1026  if (stream_index < 0)
1027  return stream_index;
1028 
1029  ret = av_get_packet(pb, pkt, len - 32);
1030  if (ret < 0)
1031  return ret;
1032  pkt->stream_index = stream_index;
1033  pkt->pts = wtv->pts;
1034  avio_skip(pb, WTV_PAD8(len) - len);
1035  return 0;
1036 }
1037 
1038  static int read_seek(AVFormatContext *s, int stream_index,
1039  int64_t ts, int flags)
1040 {
1041  WtvContext *wtv = s->priv_data;
1042  AVIOContext *pb = wtv->pb;
1043  AVStream *st = s->streams[0];
1044  int64_t ts_relative;
1045  int i;
1046 
1047  if ((flags & AVSEEK_FLAG_FRAME) || (flags & AVSEEK_FLAG_BYTE))
1048  return AVERROR(ENOSYS);
1049 
1050  /* timestamp adjustment is required because wtv->pts values are absolute,
1051  * whereas AVIndexEntry->timestamp values are relative to epoch. */
1052  ts_relative = ts;
1053  if (wtv->epoch != AV_NOPTS_VALUE)
1054  ts_relative -= wtv->epoch;
1055 
1056  i = ff_index_search_timestamp(wtv->index_entries, wtv->nb_index_entries, ts_relative, flags);
1057  if (i < 0) {
1058  if (wtv->last_valid_pts == AV_NOPTS_VALUE || ts < wtv->last_valid_pts) {
1059  if (avio_seek(pb, 0, SEEK_SET) < 0)
1060  return -1;
1061  } else if (st->duration != AV_NOPTS_VALUE && ts_relative > st->duration && wtv->nb_index_entries) {
1062  if (avio_seek(pb, wtv->index_entries[wtv->nb_index_entries - 1].pos, SEEK_SET) < 0)
1063  return -1;
1064  }
1065  if (parse_chunks(s, SEEK_TO_PTS, ts, 0) < 0)
1066  return AVERROR(ERANGE);
1067  return 0;
1068  }
1069  if (avio_seek(pb, wtv->index_entries[i].pos, SEEK_SET) < 0)
1070  return -1;
1071  wtv->pts = wtv->index_entries[i].timestamp;
1072  if (wtv->epoch != AV_NOPTS_VALUE)
1073  wtv->pts += wtv->epoch;
1074  wtv->last_valid_pts = wtv->pts;
1075  return 0;
1076 }
1077 
1078  static int read_close(AVFormatContext *s)
1079 {
1080  WtvContext *wtv = s->priv_data;
1081  av_freep(&wtv->index_entries);
1082  wtvfile_close(wtv->pb);
1083  return 0;
1084 }
1085 
1086  AVInputFormat ff_wtv_demuxer = {
1087  .name = "wtv",
1088  .long_name = NULL_IF_CONFIG_SMALL("Windows Television (WTV)"),
1089  .priv_data_size = sizeof(WtvContext),
1090  .read_probe = read_probe,
1091  .read_header = read_header,
1092  .read_packet = read_packet,
1093  .read_seek = read_seek,
1094  .read_close = read_close,
1095  .flags = AVFMT_SHOW_IDS,
1096 };
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