libavformat/wtvdec.c

   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 "libavutil/intreadwrite.h"
  29 #include "libavutil/intfloat_readwrite.h"
  30 #include "avformat.h"
  31 #include "internal.h"
  32 #include "wtv.h"
  33 #include "mpegts.h"
  34 #include <strings.h>
  35
  36 /* Macros for formating GUIDs */
  37 #define PRI_PRETTY_GUID \
  38     "%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x"
  39 #define ARG_PRETTY_GUID(g) \
  40     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]
  41 #define LEN_PRETTY_GUID 34
  42
  43 /*
  44  *
  45  * File system routines
  46  *
  47  */
  48
  49 typedef struct {
  50     AVIOContext *pb_filesystem;  /** file system (AVFormatContext->pb) */
  51
  52     int sector_bits;     /** sector shift bits; used to convert sector number into pb_filesystem offset */
  53     uint32_t *sectors;   /** file allocation table */
  54     int nb_sectors;      /** number of sectors */
  55
  56     int error;
  57     int64_t position;
  58     int64_t length;
  59 } WtvFile;
  60
  61 /**
  62  * @return bytes read, 0 on end of file, or <0 on error
  63  */
  64 static int wtvfile_read_packet(void *opaque, uint8_t *buf, int buf_size)
  65 {
  66     WtvFile *wf = opaque;
  67     AVIOContext *pb = wf->pb_filesystem;
  68     int nread = 0;
  69
  70     if (wf->error || pb->error)
  71         return -1;
  72     if (wf->position >= wf->length || url_feof(pb))
  73         return 0;
  74
  75     buf_size = FFMIN(buf_size, wf->length - wf->position);
  76     while(nread < buf_size) {
  77         int n;
  78         int remaining_in_sector = (1 << wf->sector_bits) - (wf->position & ((1 << wf->sector_bits) - 1));
  79         int read_request        = FFMIN(buf_size - nread, remaining_in_sector);
  80
  81         n = avio_read(pb, buf, read_request);
  82         if (n <= 0)
  83             break;
  84         nread += n;
  85         buf += n;
  86         wf->position += n;
  87         if (n == remaining_in_sector) {
  88             int i = wf->position >> wf->sector_bits;
  89             if (i >= wf->nb_sectors ||
  90                 (wf->sectors[i] != wf->sectors[i - 1] + (1 << (wf->sector_bits - WTV_SECTOR_BITS)) &&
  91                 avio_seek(pb, (int64_t)wf->sectors[i] << WTV_SECTOR_BITS, SEEK_SET) < 0)) {
  92                 wf->error = 1;
  93                 break;
  94             }
  95         }
  96     }
  97     return nread;
  98 }
  99
 100 /**
 101  * @return position (or file length)
 102  */
 103 static int64_t wtvfile_seek(void *opaque, int64_t offset, int whence)
 104 {
 105     WtvFile *wf = opaque;
 106     AVIOContext *pb = wf->pb_filesystem;
 107
 108     if (whence == AVSEEK_SIZE)
 109         return wf->length;
 110     else if (whence == SEEK_CUR)
 111         offset = wf->position + offset;
 112     else if (whence == SEEK_END)
 113         offset = wf->length;
 114
 115     wf->error = offset < 0 || offset >= wf->length ||
 116                 avio_seek(pb, ((int64_t)wf->sectors[offset >> wf->sector_bits] << WTV_SECTOR_BITS)
 117                               + (offset & ((1 << wf->sector_bits) - 1)), SEEK_SET) < 0;
 118     wf->position = offset;
 119     return offset;
 120 }
 121
 122 /**
 123  * read non-zero integers (le32) from input stream
 124  * @param pb
 125  * @param[out] data destination
 126  * @param     count maximum number of integers to read
 127  * @return    total number of integers read
 128  */
 129 static int read_ints(AVIOContext *pb, uint32_t *data, int count)
 130 {
 131     int i, total = 0;
 132     for (i = 0; i < count; i++) {
 133         if ((data[total] = avio_rl32(pb)))
 134            total++;
 135     }
 136     return total;
 137 }
 138
 139 /**
 140  * Open file
 141  * @param first_sector  First sector
 142  * @param length        Length of file (bytes)
 143  * @param depth         File allocation table depth
 144  * @return NULL on error
 145  */
 146 static AVIOContext * wtvfile_open_sector(int first_sector, uint64_t length, int depth, AVFormatContext *s)
 147 {
 148     AVIOContext *pb;
 149     WtvFile *wf;
 150     uint8_t *buffer;
 151
 152     if (avio_seek(s->pb, first_sector << WTV_SECTOR_BITS, SEEK_SET) < 0)
 153         return NULL;
 154
 155     wf = av_mallocz(sizeof(WtvFile));
 156     if (!wf)
 157         return NULL;
 158
 159     if (depth == 0) {
 160         wf->sectors = av_malloc(sizeof(uint32_t));
 161         if (!wf->sectors) {
 162             av_free(wf);
 163             return NULL;
 164         }
 165         wf->sectors[0]  = first_sector;
 166         wf->nb_sectors  = 1;
 167     } else if (depth == 1) {
 168         wf->sectors = av_malloc(WTV_SECTOR_SIZE);
 169         if (!wf->sectors) {
 170             av_free(wf);
 171             return NULL;
 172         }
 173         wf->nb_sectors  = read_ints(s->pb, wf->sectors, WTV_SECTOR_SIZE / 4);
 174     } else if (depth == 2) {
 175         uint32_t sectors1[WTV_SECTOR_SIZE / 4];
 176         int nb_sectors1 = read_ints(s->pb, sectors1, WTV_SECTOR_SIZE / 4);
 177         int i;
 178
 179         wf->sectors = av_malloc(nb_sectors1 << WTV_SECTOR_BITS);
 180         if (!wf->sectors) {
 181             av_free(wf);
 182             return NULL;
 183         }
 184         wf->nb_sectors = 0;
 185         for (i = 0; i < nb_sectors1; i++) {
 186             if (avio_seek(s->pb, (int64_t)sectors1[i] << WTV_SECTOR_BITS, SEEK_SET) < 0)
 187                 break;
 188             wf->nb_sectors += read_ints(s->pb, wf->sectors + i * WTV_SECTOR_SIZE / 4, WTV_SECTOR_SIZE / 4);
 189         }
 190     } else {
 191         av_log(s, AV_LOG_ERROR, "unsupported file allocation table depth (0x%x)\n", depth);
 192         av_free(wf);
 193         return NULL;
 194     }
 195     wf->sector_bits = length & (1ULL<<63) ? WTV_SECTOR_BITS : WTV_BIGSECTOR_BITS;
 196
 197     if (!wf->nb_sectors) {
 198         av_free(wf->sectors);
 199         av_free(wf);
 200         return NULL;
 201     }
 202
 203     /* check length */
 204     length &= 0xFFFFFFFFFFFF;
 205     if (length > ((int64_t)wf->nb_sectors << wf->sector_bits)) {
 206         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);
 207         length = (int64_t)wf->nb_sectors <<  wf->sector_bits;
 208     }
 209     wf->length = length;
 210
 211     /* seek to intial sector */
 212     wf->position = 0;
 213     if (avio_seek(s->pb, (int64_t)wf->sectors[0] << WTV_SECTOR_BITS, SEEK_SET) < 0) {
 214         av_free(wf->sectors);
 215         av_free(wf);
 216         return NULL;
 217     }
 218
 219     wf->pb_filesystem = s->pb;
 220     buffer = av_malloc(1 << wf->sector_bits);
 221     if (!buffer) {
 222         av_free(wf->sectors);
 223         av_free(wf);
 224         return NULL;
 225     }
 226
 227     pb = avio_alloc_context(buffer, 1 << wf->sector_bits, 0, wf,
 228                            wtvfile_read_packet, NULL, wtvfile_seek);
 229     if (!pb) {
 230         av_free(buffer);
 231         av_free(wf->sectors);
 232         av_free(wf);
 233     }
 234     return pb;
 235 }
 236
 237 /**
 238  * Open file using filename
 239  * @param[in]  buf       directory buffer
 240  * @param      buf_size  directory buffer size
 241  * @param[in]  filename
 242  * @param      filename_size size of filename
 243  * @return NULL on error
 244  */
 245 static AVIOContext * wtvfile_open2(AVFormatContext *s, const uint8_t *buf, int buf_size, const uint8_t *filename, int filename_size)
 246 {
 247     const uint8_t *buf_end = buf + buf_size;
 248
 249     while(buf + 48 <= buf_end) {
 250         int dir_length, name_size, first_sector, depth;
 251         uint64_t file_length;
 252         const uint8_t *name;
 253         if (ff_guidcmp(buf, ff_dir_entry_guid)) {
 254             av_log(s, AV_LOG_ERROR, "unknown guid "FF_PRI_GUID", expected dir_entry_guid; "
 255                    "remaining directory entries ignored\n", FF_ARG_GUID(buf));
 256             break;
 257         }
 258         dir_length  = AV_RL16(buf + 16);
 259         file_length = AV_RL64(buf + 24);
 260         name_size   = 2 * AV_RL32(buf + 32);
 261         if (buf + 48 + name_size > buf_end) {
 262             av_log(s, AV_LOG_ERROR, "filename exceeds buffer size; remaining directory entries ignored\n");
 263             break;
 264         }
 265         first_sector = AV_RL32(buf + 40 + name_size);
 266         depth        = AV_RL32(buf + 44 + name_size);
 267
 268         /* compare file name; test optional null terminator */
 269         name = buf + 40;
 270         if (name_size >= filename_size &&
 271             !memcmp(name, filename, filename_size) &&
 272             (name_size < filename_size + 2 || !AV_RN16(name + filename_size)))
 273             return wtvfile_open_sector(first_sector, file_length, depth, s);
 274
 275         buf += dir_length;
 276     }
 277     return 0;
 278 }
 279
 280 #define wtvfile_open(s, buf, buf_size, filename) \
 281     wtvfile_open2(s, buf, buf_size, filename, sizeof(filename))
 282
 283 /**
 284  * Close file opened with wtvfile_open_sector(), or wtv_open()
 285  */
 286 static void wtvfile_close(AVIOContext *pb)
 287 {
 288     WtvFile *wf = pb->opaque;
 289     av_free(wf->sectors);
 290     av_free(pb);
 291 }
 292
 293 /*
 294  *
 295  * Main demuxer
 296  *
 297  */
 298
 299 typedef struct {
 300     int seen_data;
 301 } WtvStream;
 302
 303 typedef struct {
 304     AVIOContext *pb;       /** timeline file */
 305     int64_t epoch;
 306     int64_t pts;             /** pts for next data chunk */
 307     int64_t last_valid_pts;  /** latest valid pts, used for interative seeking */
 308
 309     /* maintain private seek index, as the AVIndexEntry->pos is relative to the
 310        start of the 'timeline' file, not the file system (AVFormatContext->pb) */
 311     AVIndexEntry *index_entries;
 312     int nb_index_entries;
 313     unsigned int index_entries_allocated_size;
 314 } WtvContext;
 315
 316 /* WTV GUIDs */
 317 static const ff_asf_guid metadata_guid =
 318     {0x5A,0xFE,0xD7,0x6D,0xC8,0x1D,0x8F,0x4A,0x99,0x22,0xFA,0xB1,0x1C,0x38,0x14,0x53};
 319 static const ff_asf_guid stream2_guid =
 320     {0xA2,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D};
 321 static const ff_asf_guid EVENTID_SubtitleSpanningEvent =
 322     {0x48,0xC0,0xCE,0x5D,0xB9,0xD0,0x63,0x41,0x87,0x2C,0x4F,0x32,0x22,0x3B,0xE8,0x8A};
 323 static const ff_asf_guid EVENTID_LanguageSpanningEvent =
 324     {0x6D,0x66,0x92,0xE2,0x02,0x9C,0x8D,0x44,0xAA,0x8D,0x78,0x1A,0x93,0xFD,0xC3,0x95};
 325 static const ff_asf_guid EVENTID_AudioDescriptorSpanningEvent =
 326     {0x1C,0xD4,0x7B,0x10,0xDA,0xA6,0x91,0x46,0x83,0x69,0x11,0xB2,0xCD,0xAA,0x28,0x8E};
 327 static const ff_asf_guid EVENTID_CtxADescriptorSpanningEvent =
 328     {0xE6,0xA2,0xB4,0x3A,0x47,0x42,0x34,0x4B,0x89,0x6C,0x30,0xAF,0xA5,0xD2,0x1C,0x24};
 329 static const ff_asf_guid EVENTID_CSDescriptorSpanningEvent =
 330     {0xD9,0x79,0xE7,0xEf,0xF0,0x97,0x86,0x47,0x80,0x0D,0x95,0xCF,0x50,0x5D,0xDC,0x66};
 331 static const ff_asf_guid EVENTID_DVBScramblingControlSpanningEvent =
 332     {0xC4,0xE1,0xD4,0x4B,0xA1,0x90,0x09,0x41,0x82,0x36,0x27,0xF0,0x0E,0x7D,0xCC,0x5B};
 333 static const ff_asf_guid EVENTID_StreamIDSpanningEvent =
 334     {0x68,0xAB,0xF1,0xCA,0x53,0xE1,0x41,0x4D,0xA6,0xB3,0xA7,0xC9,0x98,0xDB,0x75,0xEE};
 335 static const ff_asf_guid EVENTID_TeletextSpanningEvent =
 336     {0x50,0xD9,0x99,0x95,0x33,0x5F,0x17,0x46,0xAF,0x7C,0x1E,0x54,0xB5,0x10,0xDA,0xA3};
 337 static const ff_asf_guid EVENTID_AudioTypeSpanningEvent =
 338     {0xBE,0xBF,0x1C,0x50,0x49,0xB8,0xCE,0x42,0x9B,0xE9,0x3D,0xB8,0x69,0xFB,0x82,0xB3};
 339
 340 /* Windows media GUIDs */
 341
 342 /* Media types */
 343 static const ff_asf_guid mediasubtype_mpeg1payload =
 344     {0x81,0xEB,0x36,0xE4,0x4F,0x52,0xCE,0x11,0x9F,0x53,0x00,0x20,0xAF,0x0B,0xA7,0x70};
 345 static const ff_asf_guid mediatype_mpeg2_sections =
 346     {0x6C,0x17,0x5F,0x45,0x06,0x4B,0xCE,0x47,0x9A,0xEF,0x8C,0xAE,0xF7,0x3D,0xF7,0xB5};
 347 static const ff_asf_guid mediatype_mpeg2_pes =
 348     {0x20,0x80,0x6D,0xE0,0x46,0xDB,0xCF,0x11,0xB4,0xD1,0x00,0x80,0x5F,0x6C,0xBB,0xEA};
 349 static const ff_asf_guid mediatype_mstvcaption =
 350     {0x89,0x8A,0x8B,0xB8,0x49,0xB0,0x80,0x4C,0xAD,0xCF,0x58,0x98,0x98,0x5E,0x22,0xC1};
 351
 352 /* Media subtypes */
 353 static const ff_asf_guid mediasubtype_cpfilters_processed =
 354     {0x28,0xBD,0xAD,0x46,0xD0,0x6F,0x96,0x47,0x93,0xB2,0x15,0x5C,0x51,0xDC,0x04,0x8D};
 355 static const ff_asf_guid mediasubtype_dvb_subtitle =
 356     {0xC3,0xCB,0xFF,0x34,0xB3,0xD5,0x71,0x41,0x90,0x02,0xD4,0xC6,0x03,0x01,0x69,0x7F};
 357 static const ff_asf_guid mediasubtype_teletext =
 358     {0xE3,0x76,0x2A,0xF7,0x0A,0xEB,0xD0,0x11,0xAC,0xE4,0x00,0x00,0xC0,0xCC,0x16,0xBA};
 359 static const ff_asf_guid mediasubtype_dtvccdata =
 360     {0xAA,0xDD,0x2A,0xF5,0xF0,0x36,0xF5,0x43,0x95,0xEA,0x6D,0x86,0x64,0x84,0x26,0x2A};
 361 static const ff_asf_guid mediasubtype_mpeg2_sections =
 362     {0x79,0x85,0x9F,0x4A,0xF8,0x6B,0x92,0x43,0x8A,0x6D,0xD2,0xDD,0x09,0xFA,0x78,0x61};
 363
 364 /* Formats */
 365 static const ff_asf_guid format_cpfilters_processed =
 366     {0x6F,0xB3,0x39,0x67,0x5F,0x1D,0xC2,0x4A,0x81,0x92,0x28,0xBB,0x0E,0x73,0xD1,0x6A};
 367 static const ff_asf_guid format_waveformatex =
 368     {0x81,0x9F,0x58,0x05,0x56,0xC3,0xCE,0x11,0xBF,0x01,0x00,0xAA,0x00,0x55,0x59,0x5A};
 369 static const ff_asf_guid format_videoinfo2 =
 370     {0xA0,0x76,0x2A,0xF7,0x0A,0xEB,0xD0,0x11,0xAC,0xE4,0x00,0x00,0xC0,0xCC,0x16,0xBA};
 371 static const ff_asf_guid format_mpeg2_video =
 372     {0xE3,0x80,0x6D,0xE0,0x46,0xDB,0xCF,0x11,0xB4,0xD1,0x00,0x80,0x5F,0x6C,0xBB,0xEA};
 373
 374 static int read_probe(AVProbeData *p)
 375 {
 376     return ff_guidcmp(p->buf, ff_wtv_guid) ? 0 : AVPROBE_SCORE_MAX;
 377 }
 378
 379 /**
 380  * Convert win32 FILETIME to ISO-8601 string
 381  */
 382 static void filetime_to_iso8601(char *buf, int buf_size, int64_t value)
 383 {
 384     time_t t = (value / 10000000LL) - 11644473600LL;
 385     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
 386 }
 387
 388 /**
 389  * Convert crazy time (100ns since 1 Jan 0001) to ISO-8601 string
 390  */
 391 static void crazytime_to_iso8601(char *buf, int buf_size, int64_t value)
 392 {
 393     time_t t = (value / 10000000LL) - 719162LL*86400LL;
 394     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
 395 }
 396
 397 /**
 398  * Convert OLE DATE to ISO-8601 string
 399  * @return <0 on error
 400  */
 401 static int oledate_to_iso8601(char *buf, int buf_size, int64_t value)
 402 {
 403     time_t t = (av_int2dbl(value) - 25569.0) * 86400;
 404     struct tm *result= gmtime(&t);
 405     if (!result)
 406         return -1;
 407     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", result);
 408     return 0;
 409 }
 410
 411 static void get_attachment(AVFormatContext *s, AVIOContext *pb, int length)
 412 {
 413     char mime[1024];
 414     char description[1024];
 415     unsigned int filesize;
 416     AVStream *st;
 417     int64_t pos = avio_tell(pb);
 418
 419     avio_get_str16le(pb, INT_MAX, mime, sizeof(mime));
 420     if (strcmp(mime, "image/jpeg"))
 421         goto done;
 422
 423     avio_r8(pb);
 424     avio_get_str16le(pb, INT_MAX, description, sizeof(description));
 425     filesize = avio_rl32(pb);
 426     if (!filesize)
 427         goto done;
 428
 429     st = av_new_stream(s, 0);
 430     if (!st)
 431         goto done;
 432     av_dict_set(&st->metadata, "title", description, 0);
 433     st->codec->codec_id   = CODEC_ID_MJPEG;
 434     st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
 435     st->codec->extradata  = av_mallocz(filesize);
 436     if (!st->codec->extradata)
 437         goto done;
 438     st->codec->extradata_size = filesize;
 439     avio_read(pb, st->codec->extradata, filesize);
 440 done:
 441     avio_seek(pb, pos + length, SEEK_SET);
 442 }
 443
 444 static void get_tag(AVFormatContext *s, AVIOContext *pb, const char *key, int type, int length)
 445 {
 446     int buf_size = FFMAX(2*length, LEN_PRETTY_GUID) + 1;
 447     char *buf = av_malloc(buf_size);
 448     if (!buf)
 449         return;
 450
 451     if (type == 0 && length == 4) {
 452         snprintf(buf, buf_size, "%"PRIi32, avio_rl32(pb));
 453     } else if (type == 1) {
 454         avio_get_str16le(pb, length, buf, buf_size);
 455         if (!strlen(buf)) {
 456            av_free(buf);
 457            return;
 458         }
 459     } else if (type == 3 && length == 4) {
 460         strcpy(buf, avio_rl32(pb) ? "true" : "false");
 461     } else if (type == 4 && length == 8) {
 462         int64_t num = avio_rl64(pb);
 463         if (!strcmp(key, "WM/EncodingTime") ||
 464             !strcmp(key, "WM/MediaOriginalBroadcastDateTime"))
 465             filetime_to_iso8601(buf, buf_size, num);
 466         else if (!strcmp(key, "WM/WMRVEncodeTime") ||
 467                  !strcmp(key, "WM/WMRVEndTime"))
 468             crazytime_to_iso8601(buf, buf_size, num);
 469         else if (!strcmp(key, "WM/WMRVExpirationDate")) {
 470             if (oledate_to_iso8601(buf, buf_size, num) < 0 ) {
 471                 av_free(buf);
 472                 return;
 473             }
 474         } else if (!strcmp(key, "WM/WMRVBitrate"))
 475             snprintf(buf, buf_size, "%f", av_int2dbl(num));
 476         else
 477             snprintf(buf, buf_size, "%"PRIi64, num);
 478     } else if (type == 5 && length == 2) {
 479         snprintf(buf, buf_size, "%"PRIi16, avio_rl16(pb));
 480     } else if (type == 6 && length == 16) {
 481         ff_asf_guid guid;
 482         avio_read(pb, guid, 16);
 483         snprintf(buf, buf_size, PRI_PRETTY_GUID, ARG_PRETTY_GUID(guid));
 484     } else if (type == 2 && !strcmp(key, "WM/Picture")) {
 485         get_attachment(s, pb, length);
 486         av_freep(&buf);
 487         return;
 488     } else {
 489         av_freep(&buf);
 490         av_log(s, AV_LOG_WARNING, "unsupported metadata entry; key:%s, type:%d, length:0x%x\n", key, type, length);
 491         avio_skip(pb, length);
 492         return;
 493     }
 494
 495     av_dict_set(&s->metadata, key, buf, 0);
 496     av_freep(&buf);
 497 }
 498
 499 /**
 500  * Parse metadata entries
 501  */
 502 static void parse_legacy_attrib(AVFormatContext *s, AVIOContext *pb)
 503 {
 504     ff_asf_guid guid;
 505     int length, type;
 506     while(!url_feof(pb)) {
 507         char key[1024];
 508         ff_get_guid(pb, &guid);
 509         type   = avio_rl32(pb);
 510         length = avio_rl32(pb);
 511         if (!length)
 512             break;
 513         if (ff_guidcmp(&guid, metadata_guid)) {
 514             av_log(s, AV_LOG_WARNING, "unknown guid "FF_PRI_GUID", expected metadata_guid; "
 515                    "remaining metadata entries ignored\n", FF_ARG_GUID(guid));
 516             break;
 517         }
 518         avio_get_str16le(pb, INT_MAX, key, sizeof(key));
 519         get_tag(s, pb, key, type, length);
 520     }
 521
 522     ff_metadata_conv(&s->metadata, NULL, ff_asf_metadata_conv);
 523 }
 524
 525 /**
 526  * parse VIDEOINFOHEADER2 structure
 527  * @return bytes consumed
 528  */
 529 static int parse_videoinfoheader2(AVFormatContext *s, AVStream *st)
 530 {
 531     WtvContext *wtv = s->priv_data;
 532     AVIOContext *pb = wtv->pb;
 533
 534     avio_skip(pb, 72);  // picture aspect ratio is unreliable
 535     ff_get_bmp_header(pb, st);
 536
 537     return 72 + 40;
 538 }
 539
 540 /**
 541  * Parse MPEG1WAVEFORMATEX extradata structure
 542  */
 543 static void parse_mpeg1waveformatex(AVStream *st)
 544 {
 545     /* fwHeadLayer */
 546     switch (AV_RL16(st->codec->extradata)) {
 547     case 0x0001 : st->codec->codec_id = CODEC_ID_MP1; break;
 548     case 0x0002 : st->codec->codec_id = CODEC_ID_MP2; break;
 549     case 0x0004 : st->codec->codec_id = CODEC_ID_MP3; break;
 550     }
 551
 552     st->codec->bit_rate = AV_RL32(st->codec->extradata + 2); /* dwHeadBitrate */
 553
 554     /* dwHeadMode */
 555     switch (AV_RL16(st->codec->extradata + 6)) {
 556     case 1 : case 2 : case 4 : st->codec->channels = 2; break;
 557     case 8 :                   st->codec->channels = 1; break;
 558     }
 559 }
 560
 561 /**
 562  * Initialise stream
 563  * @param st Stream to initialise, or NULL to create and initialise new stream
 564  * @return NULL on error
 565  */
 566 static AVStream * new_stream(AVFormatContext *s, AVStream *st, int sid, int codec_type)
 567 {
 568     if (st) {
 569         if (st->codec->extradata) {
 570             av_freep(&st->codec->extradata);
 571             st->codec->extradata_size = 0;
 572         }
 573     } else {
 574         WtvStream *wst = av_mallocz(sizeof(WtvStream));
 575         if (!wst)
 576             return NULL;
 577         st = av_new_stream(s, sid);
 578         if (!st)
 579             return NULL;
 580         st->priv_data = wst;
 581     }
 582     st->codec->codec_type = codec_type;
 583     st->need_parsing      = AVSTREAM_PARSE_FULL;
 584     av_set_pts_info(st, 64, 1, 10000000);
 585     return st;
 586 }
 587
 588 /**
 589  * parse Media Type structure and populate stream
 590  * @param st         Stream, or NULL to create new stream
 591  * @param mediatype  Mediatype GUID
 592  * @param subtype    Subtype GUID
 593  * @param formattype Format GUID
 594  * @param size       Size of format buffer
 595  * @return NULL on error
 596  */
 597 static AVStream * parse_media_type(AVFormatContext *s, AVStream *st, int sid,
 598                                    ff_asf_guid mediatype, ff_asf_guid subtype,
 599                                    ff_asf_guid formattype, int size)
 600 {
 601     WtvContext *wtv = s->priv_data;
 602     AVIOContext *pb = wtv->pb;
 603     if (!ff_guidcmp(subtype, mediasubtype_cpfilters_processed) &&
 604         !ff_guidcmp(formattype, format_cpfilters_processed)) {
 605         ff_asf_guid actual_subtype;
 606         ff_asf_guid actual_formattype;
 607
 608         if (size < 32) {
 609             av_log(s, AV_LOG_WARNING, "format buffer size underflow\n");
 610             avio_skip(pb, size);
 611             return NULL;
 612         }
 613
 614         avio_skip(pb, size - 32);
 615         ff_get_guid(pb, &actual_subtype);
 616         ff_get_guid(pb, &actual_formattype);
 617         avio_seek(pb, -size, SEEK_CUR);
 618
 619         st = parse_media_type(s, st, sid, mediatype, actual_subtype, actual_formattype, size - 32);
 620         avio_skip(pb, 32);
 621         return st;
 622     } else if (!ff_guidcmp(mediatype, ff_mediatype_audio)) {
 623         st = new_stream(s, st, sid, AVMEDIA_TYPE_AUDIO);
 624         if (!st)
 625             return NULL;
 626         if (!ff_guidcmp(formattype, format_waveformatex)) {
 627             int ret = ff_get_wav_header(pb, st->codec, size);
 628             if (ret < 0)
 629                 return NULL;
 630         } else {
 631             if (ff_guidcmp(formattype, ff_format_none))
 632                 av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
 633             avio_skip(pb, size);
 634         }
 635
 636         if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {
 637             st->codec->codec_id = ff_wav_codec_get_id(AV_RL32(subtype), st->codec->bits_per_coded_sample);
 638         } else if (!ff_guidcmp(subtype, mediasubtype_mpeg1payload)) {
 639             if (st->codec->extradata && st->codec->extradata_size >= 22)
 640                 parse_mpeg1waveformatex(st);
 641             else
 642                 av_log(s, AV_LOG_WARNING, "MPEG1WAVEFORMATEX underflow\n");
 643         } else {
 644             st->codec->codec_id = ff_codec_guid_get_id(ff_codec_wav_guids, subtype);
 645             if (st->codec->codec_id == CODEC_ID_NONE)
 646                 av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID"\n", FF_ARG_GUID(subtype));
 647         }
 648         return st;
 649     } else if (!ff_guidcmp(mediatype, ff_mediatype_video)) {
 650         st = new_stream(s, st, sid, AVMEDIA_TYPE_VIDEO);
 651         if (!st)
 652             return NULL;
 653         if (!ff_guidcmp(formattype, format_videoinfo2)) {
 654             int consumed = parse_videoinfoheader2(s, st);
 655             avio_skip(pb, FFMAX(size - consumed, 0));
 656         } else if (!ff_guidcmp(formattype, format_mpeg2_video)) {
 657             int consumed = parse_videoinfoheader2(s, st);
 658             avio_skip(pb, FFMAX(size - consumed, 0));
 659         } else {
 660             if (ff_guidcmp(formattype, ff_format_none))
 661                 av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
 662             avio_skip(pb, size);
 663         }
 664
 665         if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {
 666             st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, AV_RL32(subtype));
 667         } else {
 668             st->codec->codec_id = ff_codec_guid_get_id(ff_video_guids, subtype);
 669         }
 670         if (st->codec->codec_id == CODEC_ID_NONE)
 671             av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID"\n", FF_ARG_GUID(subtype));
 672         return st;
 673     } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_pes) &&
 674                !ff_guidcmp(subtype, mediasubtype_dvb_subtitle)) {
 675         st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);
 676         if (!st)
 677             return NULL;
 678         if (ff_guidcmp(formattype, ff_format_none))
 679             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
 680         avio_skip(pb, size);
 681         st->codec->codec_id = CODEC_ID_DVB_SUBTITLE;
 682         return st;
 683     } else if (!ff_guidcmp(mediatype, mediatype_mstvcaption) &&
 684                (!ff_guidcmp(subtype, mediasubtype_teletext) || !ff_guidcmp(subtype, mediasubtype_dtvccdata))) {
 685         st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);
 686         if (!st)
 687             return NULL;
 688         if (ff_guidcmp(formattype, ff_format_none))
 689             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
 690         avio_skip(pb, size);
 691         st->codec->codec_id   = CODEC_ID_DVB_TELETEXT;
 692         return st;
 693     } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_sections) &&
 694                !ff_guidcmp(subtype, mediasubtype_mpeg2_sections)) {
 695         if (ff_guidcmp(formattype, ff_format_none))
 696             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
 697         avio_skip(pb, size);
 698         return NULL;
 699     }
 700
 701     av_log(s, AV_LOG_WARNING, "unknown media type, mediatype:"FF_PRI_GUID
 702                               ", subtype:"FF_PRI_GUID", formattype:"FF_PRI_GUID"\n",
 703                               FF_ARG_GUID(mediatype), FF_ARG_GUID(subtype), FF_ARG_GUID(formattype));
 704     avio_skip(pb, size);
 705     return NULL;
 706 }
 707
 708 enum {
 709     SEEK_TO_DATA = 0,
 710     SEEK_TO_PTS,
 711 };
 712
 713 /**
 714  * Parse WTV chunks
 715  * @param mode SEEK_TO_DATA or SEEK_TO_PTS
 716  * @param seekts timestamp
 717  * @param[out] len_ptr Length of data chunk
 718  * @return stream index of data chunk, or <0 on error
 719  */
 720 static int parse_chunks(AVFormatContext *s, int mode, int64_t seekts, int *len_ptr)
 721 {
 722     WtvContext *wtv = s->priv_data;
 723     AVIOContext *pb = wtv->pb;
 724     while (!url_feof(pb)) {
 725         ff_asf_guid g;
 726         int len, sid, consumed;
 727
 728         ff_get_guid(pb, &g);
 729         len = avio_rl32(pb);
 730         if (len < 32)
 731             break;
 732         sid = avio_rl32(pb) & 0x7FFF;
 733         avio_skip(pb, 8);
 734         consumed = 32;
 735
 736         if (!ff_guidcmp(g, ff_stream_guid)) {
 737             if (ff_find_stream_index(s, sid) < 0) {
 738                 ff_asf_guid mediatype, subtype, formattype;
 739                 int size;
 740                 avio_skip(pb, 28);
 741                 ff_get_guid(pb, &mediatype);
 742                 ff_get_guid(pb, &subtype);
 743                 avio_skip(pb, 12);
 744                 ff_get_guid(pb, &formattype);
 745                 size = avio_rl32(pb);
 746                 parse_media_type(s, 0, sid, mediatype, subtype, formattype, size);
 747                 consumed += 92 + size;
 748             }
 749         } else if (!ff_guidcmp(g, stream2_guid)) {
 750             int stream_index = ff_find_stream_index(s, sid);
 751             if (stream_index >= 0 && !((WtvStream*)s->streams[stream_index]->priv_data)->seen_data) {
 752                 ff_asf_guid mediatype, subtype, formattype;
 753                 int size;
 754                 avio_skip(pb, 12);
 755                 ff_get_guid(pb, &mediatype);
 756                 ff_get_guid(pb, &subtype);
 757                 avio_skip(pb, 12);
 758                 ff_get_guid(pb, &formattype);
 759                 size = avio_rl32(pb);
 760                 parse_media_type(s, s->streams[stream_index], sid, mediatype, subtype, formattype, size);
 761                 consumed += 76 + size;
 762             }
 763         } else if (!ff_guidcmp(g, EVENTID_AudioDescriptorSpanningEvent) ||
 764                    !ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
 765                    !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent) ||
 766                    !ff_guidcmp(g, EVENTID_StreamIDSpanningEvent) ||
 767                    !ff_guidcmp(g, EVENTID_SubtitleSpanningEvent) ||
 768                    !ff_guidcmp(g, EVENTID_TeletextSpanningEvent)) {
 769             int stream_index = ff_find_stream_index(s, sid);
 770             if (stream_index >= 0) {
 771                 AVStream *st = s->streams[stream_index];
 772                 uint8_t buf[258];
 773                 const uint8_t *pbuf = buf;
 774                 int buf_size;
 775
 776                 avio_skip(pb, 8);
 777                 consumed += 8;
 778                 if (!ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
 779                     !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent)) {
 780                     avio_skip(pb, 6);
 781                     consumed += 6;
 782                 }
 783
 784                 buf_size = FFMIN(len - consumed, sizeof(buf));
 785                 avio_read(pb, buf, buf_size);
 786                 consumed += buf_size;
 787                 ff_parse_mpeg2_descriptor(s, st, 0, &pbuf, buf + buf_size, 0, 0, 0, 0);
 788             }
 789         } else if (!ff_guidcmp(g, EVENTID_AudioTypeSpanningEvent)) {
 790             int stream_index = ff_find_stream_index(s, sid);
 791             if (stream_index >= 0) {
 792                 AVStream *st = s->streams[stream_index];
 793                 int audio_type;
 794                 avio_skip(pb, 8);
 795                 audio_type = avio_r8(pb);
 796                 if (audio_type == 2)
 797                     st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
 798                 else if (audio_type == 3)
 799                     st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
 800                 consumed += 9;
 801             }
 802         } else if (!ff_guidcmp(g, EVENTID_DVBScramblingControlSpanningEvent)) {
 803             int stream_index = ff_find_stream_index(s, sid);
 804             if (stream_index >= 0) {
 805                 avio_skip(pb, 12);
 806                 if (avio_rl32(pb))
 807                     av_log(s, AV_LOG_WARNING, "DVB scrambled stream detected (st:%d), decoding will likely fail\n", stream_index);
 808                 consumed += 16;
 809             }
 810         } else if (!ff_guidcmp(g, EVENTID_LanguageSpanningEvent)) {
 811             int stream_index = ff_find_stream_index(s, sid);
 812             if (stream_index >= 0) {
 813                 AVStream *st = s->streams[stream_index];
 814                 uint8_t language[4];
 815                 avio_skip(pb, 12);
 816                 avio_read(pb, language, 3);
 817                 if (language[0]) {
 818                     language[3] = 0;
 819                     av_dict_set(&st->metadata, "language", language, 0);
 820                     if (!strcmp(language, "nar") || !strcmp(language, "NAR"))
 821                         st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
 822                 }
 823                 consumed += 15;
 824             }
 825         } else if (!ff_guidcmp(g, ff_timestamp_guid)) {
 826             int stream_index = ff_find_stream_index(s, sid);
 827             if (stream_index >= 0) {
 828                 avio_skip(pb, 8);
 829                 wtv->pts = avio_rl64(pb);
 830                 consumed += 16;
 831                 if (wtv->pts == -1)
 832                     wtv->pts = AV_NOPTS_VALUE;
 833                 else {
 834                     wtv->last_valid_pts = wtv->pts;
 835                     if (wtv->epoch == AV_NOPTS_VALUE || wtv->pts < wtv->epoch)
 836                         wtv->epoch = wtv->pts;
 837                 if (mode == SEEK_TO_PTS && wtv->pts >= seekts) {
 838 #define WTV_PAD8(x) (((x) + 7) & ~7)
 839                     avio_skip(pb, WTV_PAD8(len) - consumed);
 840                     return 0;
 841                 }
 842                 }
 843             }
 844         } else if (!ff_guidcmp(g, ff_data_guid)) {
 845             int stream_index = ff_find_stream_index(s, sid);
 846             if (mode == SEEK_TO_DATA && stream_index >= 0 && len > 32) {
 847                 WtvStream *wst = s->streams[stream_index]->priv_data;
 848                 wst->seen_data = 1;
 849                 if (len_ptr) {
 850                     *len_ptr = len;
 851                 }
 852                 return stream_index;
 853             }
 854         } else if (
 855             !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}) ||
 856             !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}) ||
 857             !ff_guidcmp(g, /* DSATTRIB_TRANSPORT_PROPERTIES */ (const ff_asf_guid){0x12,0xF6,0x22,0xB6,0xAD,0x47,0x71,0x46,0xAD,0x6C,0x05,0xA9,0x8E,0x65,0xDE,0x3A}) ||
 858             !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}) ||
 859             !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}) ||
 860             !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}) ||
 861             !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}) ||
 862             !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}) ||
 863             !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}) ||
 864             !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}) ||
 865             !ff_guidcmp(g, (const ff_asf_guid){0x1E,0xBE,0xC3,0xC5,0x43,0x92,0xDC,0x11,0x85,0xE5,0x00,0x12,0x3F,0x6F,0x73,0xB9}) ||
 866             !ff_guidcmp(g, (const ff_asf_guid){0x3B,0x86,0xA2,0xB1,0xEB,0x1E,0xC3,0x44,0x8C,0x88,0x1C,0xA3,0xFF,0xE3,0xE7,0x6A}) ||
 867             !ff_guidcmp(g, (const ff_asf_guid){0x4E,0x7F,0x4C,0x5B,0xC4,0xD0,0x38,0x4B,0xA8,0x3E,0x21,0x7F,0x7B,0xBF,0x52,0xE7}) ||
 868             !ff_guidcmp(g, (const ff_asf_guid){0x63,0x36,0xEB,0xFE,0xA1,0x7E,0xD9,0x11,0x83,0x08,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
 869             !ff_guidcmp(g, (const ff_asf_guid){0x70,0xE9,0xF1,0xF8,0x89,0xA4,0x4C,0x4D,0x83,0x73,0xB8,0x12,0xE0,0xD5,0xF8,0x1E}) ||
 870             !ff_guidcmp(g, (const ff_asf_guid){0x96,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
 871             !ff_guidcmp(g, (const ff_asf_guid){0x97,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
 872             !ff_guidcmp(g, (const ff_asf_guid){0xA1,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D})) {
 873             //ignore known guids
 874         } else
 875             av_log(s, AV_LOG_WARNING, "unsupported chunk:"FF_PRI_GUID"\n", FF_ARG_GUID(g));
 876
 877         avio_skip(pb, WTV_PAD8(len) - consumed);
 878     }
 879     return AVERROR_EOF;
 880 }
 881
 882 /* declare utf16le strings */
 883 #define _ , 0,
 884 static const uint8_t timeline_le16[] =
 885     {'t'_'i'_'m'_'e'_'l'_'i'_'n'_'e', 0};
 886 static const uint8_t table_0_entries_legacy_attrib_le16[] =
 887     {'t'_'a'_'b'_'l'_'e'_'.'_'0'_'.'_'e'_'n'_'t'_'r'_'i'_'e'_'s'_'.'_'l'_'e'_'g'_'a'_'c'_'y'_'_'_'a'_'t'_'t'_'r'_'i'_'b', 0};
 888 static const uint8_t table_0_entries_time_le16[] =
 889     {'t'_'a'_'b'_'l'_'e'_'.'_'0'_'.'_'e'_'n'_'t'_'r'_'i'_'e'_'s'_'.'_'t'_'i'_'m'_'e', 0};
 890 static const uint8_t timeline_table_0_entries_Events_le16[] =
 891     {'t'_'i'_'m'_'e'_'l'_'i'_'n'_'e'_'.'_'t'_'a'_'b'_'l'_'e'_'.'_'0'_'.'_'e'_'n'_'t'_'r'_'i'_'e'_'s'_'.'_'E'_'v'_'e'_'n'_'t'_'s', 0};
 892 #undef _
 893
 894 static int read_header(AVFormatContext *s, AVFormatParameters *ap)
 895 {
 896     WtvContext *wtv = s->priv_data;
 897     int root_sector, root_size;
 898     uint8_t root[WTV_SECTOR_SIZE];
 899     AVIOContext *pb;
 900     int64_t timeline_pos;
 901     int ret;
 902
 903     wtv->epoch          =
 904     wtv->pts            =
 905     wtv->last_valid_pts = AV_NOPTS_VALUE;
 906
 907     /* read root directory sector */
 908     avio_skip(s->pb, 0x30);
 909     root_size = avio_rl32(s->pb);
 910     if (root_size > sizeof(root)) {
 911         av_log(s, AV_LOG_ERROR, "root directory size exceeds sector size\n");
 912         return AVERROR_INVALIDDATA;
 913     }
 914     avio_skip(s->pb, 4);
 915     root_sector = avio_rl32(s->pb);
 916
 917     avio_seek(s->pb, root_sector << WTV_SECTOR_BITS, SEEK_SET);
 918     root_size = avio_read(s->pb, root, root_size);
 919     if (root_size < 0)
 920         return AVERROR_INVALIDDATA;
 921
 922     /* parse chunks up until first data chunk */
 923     wtv->pb = wtvfile_open(s, root, root_size, timeline_le16);
 924     if (!wtv->pb) {
 925         av_log(s, AV_LOG_ERROR, "timeline data missing\n");
 926         return AVERROR_INVALIDDATA;
 927     }
 928
 929     ret = parse_chunks(s, SEEK_TO_DATA, 0, 0);
 930     if (ret < 0)
 931         return ret;
 932     avio_seek(wtv->pb, -32, SEEK_CUR);
 933
 934     timeline_pos = avio_tell(s->pb); // save before opening another file
 935
 936     /* read metadata */
 937     pb = wtvfile_open(s, root, root_size, table_0_entries_legacy_attrib_le16);
 938     if (pb) {
 939         parse_legacy_attrib(s, pb);
 940         wtvfile_close(pb);
 941     }
 942
 943     /* read seek index */
 944     if (s->nb_streams) {
 945         AVStream *st = s->streams[0];
 946         pb = wtvfile_open(s, root, root_size, table_0_entries_time_le16);
 947         if (pb) {
 948             while(1) {
 949                 uint64_t timestamp = avio_rl64(pb);
 950                 uint64_t frame_nb  = avio_rl64(pb);
 951                 if (url_feof(pb))
 952                     break;
 953                 ff_add_index_entry(&wtv->index_entries, &wtv->nb_index_entries, &wtv->index_entries_allocated_size,
 954                                    0, timestamp, frame_nb, 0, AVINDEX_KEYFRAME);
 955             }
 956             wtvfile_close(pb);
 957
 958             if (wtv->nb_index_entries) {
 959                 pb = wtvfile_open(s, root, root_size, timeline_table_0_entries_Events_le16);
 960                 if (pb) {
 961                     int i;
 962                     while (1) {
 963                         uint64_t frame_nb = avio_rl64(pb);
 964                         uint64_t position = avio_rl64(pb);
 965                         if (url_feof(pb))
 966                             break;
 967                         for (i = wtv->nb_index_entries - 1; i >= 0; i--) {
 968                             AVIndexEntry *e = wtv->index_entries + i;
 969                             if (frame_nb > e->size)
 970                                 break;
 971                             if (position > e->pos)
 972                                 e->pos = position;
 973                         }
 974                     }
 975                     wtvfile_close(pb);
 976                     st->duration = wtv->index_entries[wtv->nb_index_entries - 1].timestamp;
 977                 }
 978             }
 979         }
 980     }
 981
 982     avio_seek(s->pb, timeline_pos, SEEK_SET);
 983     return 0;
 984 }
 985
 986 static int read_packet(AVFormatContext *s, AVPacket *pkt)
 987 {
 988     WtvContext *wtv = s->priv_data;
 989     AVIOContext *pb = wtv->pb;
 990     int stream_index, len, ret;
 991
 992     stream_index = parse_chunks(s, SEEK_TO_DATA, 0, &len);
 993     if (stream_index < 0)
 994         return stream_index;
 995
 996     ret = av_get_packet(pb, pkt, len - 32);
 997     if (ret < 0)
 998         return ret;
 999     pkt->stream_index = stream_index;
1000     pkt->pts          = wtv->pts;
1001     avio_skip(pb, WTV_PAD8(len) - len);
1002     return 0;
1003 }
1004
1005 static int read_seek(AVFormatContext *s, int stream_index,
1006                      int64_t ts, int flags)
1007 {
1008     WtvContext *wtv = s->priv_data;
1009     AVIOContext *pb = wtv->pb;
1010     AVStream *st = s->streams[0];
1011     int64_t ts_relative;
1012     int i;
1013
1014     if ((flags & AVSEEK_FLAG_FRAME) || (flags & AVSEEK_FLAG_BYTE))
1015         return AVERROR(ENOSYS);
1016
1017     /* timestamp adjustment is required because wtv->pts values are absolute,
1018      * whereas AVIndexEntry->timestamp values are relative to epoch. */
1019     ts_relative = ts;
1020     if (wtv->epoch != AV_NOPTS_VALUE)
1021         ts_relative -= wtv->epoch;
1022
1023     i = ff_index_search_timestamp(wtv->index_entries, wtv->nb_index_entries, ts_relative, flags);
1024     if (i < 0) {
1025         if (wtv->last_valid_pts == AV_NOPTS_VALUE || ts < wtv->last_valid_pts)
1026             avio_seek(pb, 0, SEEK_SET);
1027         else if (st->duration != AV_NOPTS_VALUE && ts_relative > st->duration && wtv->nb_index_entries)
1028             avio_seek(pb, wtv->index_entries[wtv->nb_index_entries - 1].pos, SEEK_SET);
1029         if (parse_chunks(s, SEEK_TO_PTS, ts, 0) < 0)
1030             return AVERROR(ERANGE);
1031         return 0;
1032     }
1033     wtv->pts = wtv->index_entries[i].timestamp;
1034     if (wtv->epoch != AV_NOPTS_VALUE)
1035         wtv->pts += wtv->epoch;
1036     wtv->last_valid_pts = wtv->pts;
1037     avio_seek(pb, wtv->index_entries[i].pos, SEEK_SET);
1038     return 0;
1039 }
1040
1041 static int read_close(AVFormatContext *s)
1042 {
1043     WtvContext *wtv = s->priv_data;
1044     wtvfile_close(wtv->pb);
1045     return 0;
1046 }
1047
1048 AVInputFormat ff_wtv_demuxer = {
1049     .name           = "wtv",
1050     .long_name      = NULL_IF_CONFIG_SMALL("Windows Television (WTV)"),
1051     .priv_data_size = sizeof(WtvContext),
1052     .read_probe     = read_probe,
1053     .read_header    = read_header,
1054     .read_packet    = read_packet,
1055     .read_seek      = read_seek,
1056     .read_close     = read_close,
1057     .flags          = AVFMT_SHOW_IDS,
1058 };