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         wf->sector_bits = WTV_SECTOR_BITS;
 168     } else if (depth == 1) {
 169         wf->sectors = av_malloc(WTV_SECTOR_SIZE);
 170         if (!wf->sectors) {
 171             av_free(wf);
 172             return NULL;
 173         }
 174         wf->nb_sectors  = read_ints(s->pb, wf->sectors, WTV_SECTOR_SIZE / 4);
 175         wf->sector_bits = length & (1ULL<<63) ? WTV_SECTOR_BITS : WTV_BIGSECTOR_BITS;
 176     } else if (depth == 2) {
 177         uint32_t sectors1[WTV_SECTOR_SIZE / 4];
 178         int nb_sectors1 = read_ints(s->pb, sectors1, WTV_SECTOR_SIZE / 4);
 179         int i;
 180
 181         wf->sectors = av_malloc(nb_sectors1 << WTV_SECTOR_BITS);
 182         if (!wf->sectors) {
 183             av_free(wf);
 184             return NULL;
 185         }
 186         wf->nb_sectors = 0;
 187         for (i = 0; i < nb_sectors1; i++) {
 188             if (avio_seek(s->pb, (int64_t)sectors1[i] << WTV_SECTOR_BITS, SEEK_SET) < 0)
 189                 break;
 190             wf->nb_sectors += read_ints(s->pb, wf->sectors + i * WTV_SECTOR_SIZE / 4, WTV_SECTOR_SIZE / 4);
 191         }
 192         wf->sector_bits = length & (1ULL<<63) ? WTV_SECTOR_BITS : WTV_BIGSECTOR_BITS;
 193     } else {
 194         av_log(s, AV_LOG_ERROR, "unsupported file allocation table depth (0x%x)\n", depth);
 195         av_free(wf);
 196         return NULL;
 197     }
 198
 199     if (!wf->nb_sectors) {
 200         av_free(wf->sectors);
 201         av_free(wf);
 202         return NULL;
 203     }
 204
 205     /* check length */
 206     length &= 0xFFFFFFFFFFFF;
 207     if (length > ((int64_t)wf->nb_sectors << wf->sector_bits)) {
 208         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);
 209         length = (int64_t)wf->nb_sectors <<  wf->sector_bits;
 210     }
 211     wf->length = length;
 212
 213     /* seek to intial sector */
 214     wf->position = 0;
 215     if (avio_seek(s->pb, (int64_t)wf->sectors[0] << WTV_SECTOR_BITS, SEEK_SET) < 0) {
 216         av_free(wf->sectors);
 217         av_free(wf);
 218         return NULL;
 219     }
 220
 221     wf->pb_filesystem = s->pb;
 222     buffer = av_malloc(1 << wf->sector_bits);
 223     if (!buffer) {
 224         av_free(wf->sectors);
 225         av_free(wf);
 226         return NULL;
 227     }
 228
 229     pb = avio_alloc_context(buffer, 1 << wf->sector_bits, 0, wf,
 230                            wtvfile_read_packet, NULL, wtvfile_seek);
 231     if (!pb) {
 232         av_free(buffer);
 233         av_free(wf->sectors);
 234         av_free(wf);
 235     }
 236     return pb;
 237 }
 238
 239 /**
 240  * Open file using filename
 241  * @param[in]  buf       directory buffer
 242  * @param      buf_size  directory buffer size
 243  * @param[in]  filename
 244  * @param      filename_size size of filename
 245  * @return NULL on error
 246  */
 247 static AVIOContext * wtvfile_open2(AVFormatContext *s, const uint8_t *buf, int buf_size, const uint8_t *filename, int filename_size)
 248 {
 249     const uint8_t *buf_end = buf + buf_size;
 250
 251     while(buf + 48 <= buf_end) {
 252         int dir_length, name_size, first_sector, depth;
 253         uint64_t file_length;
 254         const uint8_t *name;
 255         if (ff_guidcmp(buf, ff_dir_entry_guid)) {
 256             av_log(s, AV_LOG_ERROR, "unknown guid "FF_PRI_GUID", expected dir_entry_guid; "
 257                    "remaining directory entries ignored\n", FF_ARG_GUID(buf));
 258             break;
 259         }
 260         dir_length  = AV_RL16(buf + 16);
 261         file_length = AV_RL64(buf + 24);
 262         name_size   = 2 * AV_RL32(buf + 32);
 263         if (buf + 48 + name_size > buf_end) {
 264             av_log(s, AV_LOG_ERROR, "filename exceeds buffer size; remaining directory entries ignored\n");
 265             break;
 266         }
 267         first_sector = AV_RL32(buf + 40 + name_size);
 268         depth        = AV_RL32(buf + 44 + name_size);
 269
 270         /* compare file name; test optional null terminator */
 271         name = buf + 40;
 272         if (name_size >= filename_size &&
 273             !memcmp(name, filename, filename_size) &&
 274             (name_size < filename_size + 2 || !AV_RN16(name + filename_size)))
 275             return wtvfile_open_sector(first_sector, file_length, depth, s);
 276
 277         buf += dir_length;
 278     }
 279     return 0;
 280 }
 281
 282 #define wtvfile_open(s, buf, buf_size, filename) \
 283     wtvfile_open2(s, buf, buf_size, filename, sizeof(filename))
 284
 285 /**
 286  * Close file opened with wtvfile_open_sector(), or wtv_open()
 287  */
 288 static void wtvfile_close(AVIOContext *pb)
 289 {
 290     WtvFile *wf = pb->opaque;
 291     av_free(wf->sectors);
 292     av_free(pb);
 293 }
 294
 295 /*
 296  *
 297  * Main demuxer
 298  *
 299  */
 300
 301 typedef struct {
 302     int seen_data;
 303 } WtvStream;
 304
 305 typedef struct {
 306     AVIOContext *pb;       /** timeline file */
 307     int64_t epoch;
 308     int64_t pts;             /** pts for next data chunk */
 309     int64_t last_valid_pts;  /** latest valid pts, used for interative seeking */
 310
 311     /* maintain private seek index, as the AVIndexEntry->pos is relative to the
 312        start of the 'timeline' file, not the file system (AVFormatContext->pb) */
 313     AVIndexEntry *index_entries;
 314     int nb_index_entries;
 315     unsigned int index_entries_allocated_size;
 316 } WtvContext;
 317
 318 /* WTV GUIDs */
 319 static const ff_asf_guid metadata_guid =
 320     {0x5A,0xFE,0xD7,0x6D,0xC8,0x1D,0x8F,0x4A,0x99,0x22,0xFA,0xB1,0x1C,0x38,0x14,0x53};
 321 static const ff_asf_guid stream2_guid =
 322     {0xA2,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D};
 323 static const ff_asf_guid EVENTID_SubtitleSpanningEvent =
 324     {0x48,0xC0,0xCE,0x5D,0xB9,0xD0,0x63,0x41,0x87,0x2C,0x4F,0x32,0x22,0x3B,0xE8,0x8A};
 325 static const ff_asf_guid EVENTID_LanguageSpanningEvent =
 326     {0x6D,0x66,0x92,0xE2,0x02,0x9C,0x8D,0x44,0xAA,0x8D,0x78,0x1A,0x93,0xFD,0xC3,0x95};
 327 static const ff_asf_guid EVENTID_AudioDescriptorSpanningEvent =
 328     {0x1C,0xD4,0x7B,0x10,0xDA,0xA6,0x91,0x46,0x83,0x69,0x11,0xB2,0xCD,0xAA,0x28,0x8E};
 329 static const ff_asf_guid EVENTID_CtxADescriptorSpanningEvent =
 330     {0xE6,0xA2,0xB4,0x3A,0x47,0x42,0x34,0x4B,0x89,0x6C,0x30,0xAF,0xA5,0xD2,0x1C,0x24};
 331 static const ff_asf_guid EVENTID_CSDescriptorSpanningEvent =
 332     {0xD9,0x79,0xE7,0xEf,0xF0,0x97,0x86,0x47,0x80,0x0D,0x95,0xCF,0x50,0x5D,0xDC,0x66};
 333 static const ff_asf_guid EVENTID_DVBScramblingControlSpanningEvent =
 334     {0xC4,0xE1,0xD4,0x4B,0xA1,0x90,0x09,0x41,0x82,0x36,0x27,0xF0,0x0E,0x7D,0xCC,0x5B};
 335 static const ff_asf_guid EVENTID_StreamIDSpanningEvent =
 336     {0x68,0xAB,0xF1,0xCA,0x53,0xE1,0x41,0x4D,0xA6,0xB3,0xA7,0xC9,0x98,0xDB,0x75,0xEE};
 337 static const ff_asf_guid EVENTID_TeletextSpanningEvent =
 338     {0x50,0xD9,0x99,0x95,0x33,0x5F,0x17,0x46,0xAF,0x7C,0x1E,0x54,0xB5,0x10,0xDA,0xA3};
 339 static const ff_asf_guid EVENTID_AudioTypeSpanningEvent =
 340     {0xBE,0xBF,0x1C,0x50,0x49,0xB8,0xCE,0x42,0x9B,0xE9,0x3D,0xB8,0x69,0xFB,0x82,0xB3};
 341
 342 /* Windows media GUIDs */
 343
 344 /* Media types */
 345 static const ff_asf_guid mediasubtype_mpeg1payload =
 346     {0x81,0xEB,0x36,0xE4,0x4F,0x52,0xCE,0x11,0x9F,0x53,0x00,0x20,0xAF,0x0B,0xA7,0x70};
 347 static const ff_asf_guid mediatype_mpeg2_sections =
 348     {0x6C,0x17,0x5F,0x45,0x06,0x4B,0xCE,0x47,0x9A,0xEF,0x8C,0xAE,0xF7,0x3D,0xF7,0xB5};
 349 static const ff_asf_guid mediatype_mpeg2_pes =
 350     {0x20,0x80,0x6D,0xE0,0x46,0xDB,0xCF,0x11,0xB4,0xD1,0x00,0x80,0x5F,0x6C,0xBB,0xEA};
 351 static const ff_asf_guid mediatype_mstvcaption =
 352     {0x89,0x8A,0x8B,0xB8,0x49,0xB0,0x80,0x4C,0xAD,0xCF,0x58,0x98,0x98,0x5E,0x22,0xC1};
 353
 354 /* Media subtypes */
 355 static const ff_asf_guid mediasubtype_cpfilters_processed =
 356     {0x28,0xBD,0xAD,0x46,0xD0,0x6F,0x96,0x47,0x93,0xB2,0x15,0x5C,0x51,0xDC,0x04,0x8D};
 357 static const ff_asf_guid mediasubtype_dvb_subtitle =
 358     {0xC3,0xCB,0xFF,0x34,0xB3,0xD5,0x71,0x41,0x90,0x02,0xD4,0xC6,0x03,0x01,0x69,0x7F};
 359 static const ff_asf_guid mediasubtype_teletext =
 360     {0xE3,0x76,0x2A,0xF7,0x0A,0xEB,0xD0,0x11,0xAC,0xE4,0x00,0x00,0xC0,0xCC,0x16,0xBA};
 361 static const ff_asf_guid mediasubtype_dtvccdata =
 362     {0xAA,0xDD,0x2A,0xF5,0xF0,0x36,0xF5,0x43,0x95,0xEA,0x6D,0x86,0x64,0x84,0x26,0x2A};
 363 static const ff_asf_guid mediasubtype_mpeg2_sections =
 364     {0x79,0x85,0x9F,0x4A,0xF8,0x6B,0x92,0x43,0x8A,0x6D,0xD2,0xDD,0x09,0xFA,0x78,0x61};
 365
 366 /* Formats */
 367 static const ff_asf_guid format_cpfilters_processed =
 368     {0x6F,0xB3,0x39,0x67,0x5F,0x1D,0xC2,0x4A,0x81,0x92,0x28,0xBB,0x0E,0x73,0xD1,0x6A};
 369 static const ff_asf_guid format_waveformatex =
 370     {0x81,0x9F,0x58,0x05,0x56,0xC3,0xCE,0x11,0xBF,0x01,0x00,0xAA,0x00,0x55,0x59,0x5A};
 371 static const ff_asf_guid format_videoinfo2 =
 372     {0xA0,0x76,0x2A,0xF7,0x0A,0xEB,0xD0,0x11,0xAC,0xE4,0x00,0x00,0xC0,0xCC,0x16,0xBA};
 373 static const ff_asf_guid format_mpeg2_video =
 374     {0xE3,0x80,0x6D,0xE0,0x46,0xDB,0xCF,0x11,0xB4,0xD1,0x00,0x80,0x5F,0x6C,0xBB,0xEA};
 375
 376 static int read_probe(AVProbeData *p)
 377 {
 378     return ff_guidcmp(p->buf, ff_wtv_guid) ? 0 : AVPROBE_SCORE_MAX;
 379 }
 380
 381 /**
 382  * Convert win32 FILETIME to ISO-8601 string
 383  */
 384 static void filetime_to_iso8601(char *buf, int buf_size, int64_t value)
 385 {
 386     time_t t = (value / 10000000LL) - 11644473600LL;
 387     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
 388 }
 389
 390 /**
 391  * Convert crazy time (100ns since 1 Jan 0001) to ISO-8601 string
 392  */
 393 static void crazytime_to_iso8601(char *buf, int buf_size, int64_t value)
 394 {
 395     time_t t = (value / 10000000LL) - 719162LL*86400LL;
 396     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
 397 }
 398
 399 /**
 400  * Convert OLE DATE to ISO-8601 string
 401  * @return <0 on error
 402  */
 403 static int oledate_to_iso8601(char *buf, int buf_size, int64_t value)
 404 {
 405     time_t t = (av_int2dbl(value) - 25569.0) * 86400;
 406     struct tm *result= gmtime(&t);
 407     if (!result)
 408         return -1;
 409     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", result);
 410     return 0;
 411 }
 412
 413 static void get_attachment(AVFormatContext *s, AVIOContext *pb, int length)
 414 {
 415     char mime[1024];
 416     char description[1024];
 417     unsigned int filesize;
 418     AVStream *st;
 419     int64_t pos = avio_tell(pb);
 420
 421     avio_get_str16le(pb, INT_MAX, mime, sizeof(mime));
 422     if (strcmp(mime, "image/jpeg"))
 423         goto done;
 424
 425     avio_r8(pb);
 426     avio_get_str16le(pb, INT_MAX, description, sizeof(description));
 427     filesize = avio_rl32(pb);
 428     if (!filesize)
 429         goto done;
 430
 431     st = av_new_stream(s, 0);
 432     if (!st)
 433         goto done;
 434     av_dict_set(&st->metadata, "title", description, 0);
 435     st->codec->codec_id   = CODEC_ID_MJPEG;
 436     st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
 437     st->codec->extradata  = av_mallocz(filesize);
 438     if (!st->codec->extradata)
 439         goto done;
 440     st->codec->extradata_size = filesize;
 441     avio_read(pb, st->codec->extradata, filesize);
 442 done:
 443     avio_seek(pb, pos + length, SEEK_SET);
 444 }
 445
 446 static void get_tag(AVFormatContext *s, AVIOContext *pb, const char *key, int type, int length)
 447 {
 448     int buf_size = FFMAX(2*length, LEN_PRETTY_GUID) + 1;
 449     char *buf = av_malloc(buf_size);
 450     if (!buf)
 451         return;
 452
 453     if (type == 0 && length == 4) {
 454         snprintf(buf, buf_size, "%"PRIi32, avio_rl32(pb));
 455     } else if (type == 1) {
 456         avio_get_str16le(pb, length, buf, buf_size);
 457         if (!strlen(buf)) {
 458            av_free(buf);
 459            return;
 460         }
 461     } else if (type == 3 && length == 4) {
 462         strcpy(buf, avio_rl32(pb) ? "true" : "false");
 463     } else if (type == 4 && length == 8) {
 464         int64_t num = avio_rl64(pb);
 465         if (!strcmp(key, "WM/EncodingTime") ||
 466             !strcmp(key, "WM/MediaOriginalBroadcastDateTime"))
 467             filetime_to_iso8601(buf, buf_size, num);
 468         else if (!strcmp(key, "WM/WMRVEncodeTime") ||
 469                  !strcmp(key, "WM/WMRVEndTime"))
 470             crazytime_to_iso8601(buf, buf_size, num);
 471         else if (!strcmp(key, "WM/WMRVExpirationDate")) {
 472             if (oledate_to_iso8601(buf, buf_size, num) < 0 ) {
 473                 av_free(buf);
 474                 return;
 475             }
 476         } else if (!strcmp(key, "WM/WMRVBitrate"))
 477             snprintf(buf, buf_size, "%f", av_int2dbl(num));
 478         else
 479             snprintf(buf, buf_size, "%"PRIi64, num);
 480     } else if (type == 5 && length == 2) {
 481         snprintf(buf, buf_size, "%"PRIi16, avio_rl16(pb));
 482     } else if (type == 6 && length == 16) {
 483         ff_asf_guid guid;
 484         avio_read(pb, guid, 16);
 485         snprintf(buf, buf_size, PRI_PRETTY_GUID, ARG_PRETTY_GUID(guid));
 486     } else if (type == 2 && !strcmp(key, "WM/Picture")) {
 487         get_attachment(s, pb, length);
 488         av_freep(&buf);
 489         return;
 490     } else {
 491         av_freep(&buf);
 492         av_log(s, AV_LOG_WARNING, "unsupported metadata entry; key:%s, type:%d, length:0x%x\n", key, type, length);
 493         avio_skip(pb, length);
 494         return;
 495     }
 496
 497     av_dict_set(&s->metadata, key, buf, 0);
 498     av_freep(&buf);
 499 }
 500
 501 /**
 502  * Parse metadata entries
 503  */
 504 static void parse_legacy_attrib(AVFormatContext *s, AVIOContext *pb)
 505 {
 506     ff_asf_guid guid;
 507     int length, type;
 508     while(!url_feof(pb)) {
 509         char key[1024];
 510         ff_get_guid(pb, &guid);
 511         type   = avio_rl32(pb);
 512         length = avio_rl32(pb);
 513         if (!length)
 514             break;
 515         if (ff_guidcmp(&guid, metadata_guid)) {
 516             av_log(s, AV_LOG_WARNING, "unknown guid "FF_PRI_GUID", expected metadata_guid; "
 517                    "remaining metadata entries ignored\n", FF_ARG_GUID(guid));
 518             break;
 519         }
 520         avio_get_str16le(pb, INT_MAX, key, sizeof(key));
 521         get_tag(s, pb, key, type, length);
 522     }
 523
 524     ff_metadata_conv(&s->metadata, NULL, ff_asf_metadata_conv);
 525 }
 526
 527 /**
 528  * parse VIDEOINFOHEADER2 structure
 529  * @return bytes consumed
 530  */
 531 static int parse_videoinfoheader2(AVFormatContext *s, AVStream *st)
 532 {
 533     WtvContext *wtv = s->priv_data;
 534     AVIOContext *pb = wtv->pb;
 535
 536     avio_skip(pb, 72);  // picture aspect ratio is unreliable
 537     ff_get_bmp_header(pb, st);
 538
 539     return 72 + 40;
 540 }
 541
 542 /**
 543  * Parse MPEG1WAVEFORMATEX extradata structure
 544  */
 545 static void parse_mpeg1waveformatex(AVStream *st)
 546 {
 547     /* fwHeadLayer */
 548     switch (AV_RL16(st->codec->extradata)) {
 549     case 0x0001 : st->codec->codec_id = CODEC_ID_MP1; break;
 550     case 0x0002 : st->codec->codec_id = CODEC_ID_MP2; break;
 551     case 0x0004 : st->codec->codec_id = CODEC_ID_MP3; break;
 552     }
 553
 554     st->codec->bit_rate = AV_RL32(st->codec->extradata + 2); /* dwHeadBitrate */
 555
 556     /* dwHeadMode */
 557     switch (AV_RL16(st->codec->extradata + 6)) {
 558     case 1 : case 2 : case 4 : st->codec->channels = 2; break;
 559     case 8 :                   st->codec->channels = 1; break;
 560     }
 561 }
 562
 563 /**
 564  * Initialise stream
 565  * @param st Stream to initialise, or NULL to create and initialise new stream
 566  * @return NULL on error
 567  */
 568 static AVStream * new_stream(AVFormatContext *s, AVStream *st, int sid, int codec_type)
 569 {
 570     if (st) {
 571         if (st->codec->extradata) {
 572             av_freep(&st->codec->extradata);
 573             st->codec->extradata_size = 0;
 574         }
 575     } else {
 576         WtvStream *wst = av_mallocz(sizeof(WtvStream));
 577         if (!wst)
 578             return NULL;
 579         st = av_new_stream(s, sid);
 580         if (!st)
 581             return NULL;
 582         st->priv_data = wst;
 583     }
 584     st->codec->codec_type = codec_type;
 585     st->need_parsing      = AVSTREAM_PARSE_FULL;
 586     av_set_pts_info(st, 64, 1, 10000000);
 587     return st;
 588 }
 589
 590 /**
 591  * parse Media Type structure and populate stream
 592  * @param st         Stream, or NULL to create new stream
 593  * @param mediatype  Mediatype GUID
 594  * @param subtype    Subtype GUID
 595  * @param formattype Format GUID
 596  * @param size       Size of format buffer
 597  * @return NULL on error
 598  */
 599 static AVStream * parse_media_type(AVFormatContext *s, AVStream *st, int sid,
 600                                    ff_asf_guid mediatype, ff_asf_guid subtype,
 601                                    ff_asf_guid formattype, int size)
 602 {
 603     WtvContext *wtv = s->priv_data;
 604     AVIOContext *pb = wtv->pb;
 605     if (!ff_guidcmp(subtype, mediasubtype_cpfilters_processed) &&
 606         !ff_guidcmp(formattype, format_cpfilters_processed)) {
 607         ff_asf_guid actual_subtype;
 608         ff_asf_guid actual_formattype;
 609
 610         if (size < 32) {
 611             av_log(s, AV_LOG_WARNING, "format buffer size underflow\n");
 612             avio_skip(pb, size);
 613             return NULL;
 614         }
 615
 616         avio_skip(pb, size - 32);
 617         ff_get_guid(pb, &actual_subtype);
 618         ff_get_guid(pb, &actual_formattype);
 619         avio_seek(pb, -size, SEEK_CUR);
 620
 621         st = parse_media_type(s, st, sid, mediatype, actual_subtype, actual_formattype, size - 32);
 622         avio_skip(pb, 32);
 623         return st;
 624     } else if (!ff_guidcmp(mediatype, ff_mediatype_audio)) {
 625         st = new_stream(s, st, sid, AVMEDIA_TYPE_AUDIO);
 626         if (!st)
 627             return NULL;
 628         if (!ff_guidcmp(formattype, format_waveformatex)) {
 629             int ret = ff_get_wav_header(pb, st->codec, size);
 630             if (ret < 0)
 631                 return NULL;
 632         } else {
 633             if (ff_guidcmp(formattype, ff_format_none))
 634                 av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
 635             avio_skip(pb, size);
 636         }
 637
 638         if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {
 639             st->codec->codec_id = ff_wav_codec_get_id(AV_RL32(subtype), st->codec->bits_per_coded_sample);
 640         } else if (!ff_guidcmp(subtype, mediasubtype_mpeg1payload)) {
 641             if (st->codec->extradata && st->codec->extradata_size >= 22)
 642                 parse_mpeg1waveformatex(st);
 643             else
 644                 av_log(s, AV_LOG_WARNING, "MPEG1WAVEFORMATEX underflow\n");
 645         } else {
 646             st->codec->codec_id = ff_codec_guid_get_id(ff_codec_wav_guids, subtype);
 647             if (st->codec->codec_id == CODEC_ID_NONE)
 648                 av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID"\n", FF_ARG_GUID(subtype));
 649         }
 650         return st;
 651     } else if (!ff_guidcmp(mediatype, ff_mediatype_video)) {
 652         st = new_stream(s, st, sid, AVMEDIA_TYPE_VIDEO);
 653         if (!st)
 654             return NULL;
 655         if (!ff_guidcmp(formattype, format_videoinfo2)) {
 656             int consumed = parse_videoinfoheader2(s, st);
 657             avio_skip(pb, FFMAX(size - consumed, 0));
 658         } else if (!ff_guidcmp(formattype, format_mpeg2_video)) {
 659             int consumed = parse_videoinfoheader2(s, st);
 660             avio_skip(pb, FFMAX(size - consumed, 0));
 661         } else {
 662             if (ff_guidcmp(formattype, ff_format_none))
 663                 av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
 664             avio_skip(pb, size);
 665         }
 666
 667         if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {
 668             st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, AV_RL32(subtype));
 669         } else {
 670             st->codec->codec_id = ff_codec_guid_get_id(ff_video_guids, subtype);
 671         }
 672         if (st->codec->codec_id == CODEC_ID_NONE)
 673             av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID"\n", FF_ARG_GUID(subtype));
 674         return st;
 675     } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_pes) &&
 676                !ff_guidcmp(subtype, mediasubtype_dvb_subtitle)) {
 677         st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);
 678         if (!st)
 679             return NULL;
 680         if (ff_guidcmp(formattype, ff_format_none))
 681             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
 682         avio_skip(pb, size);
 683         st->codec->codec_id = CODEC_ID_DVB_SUBTITLE;
 684         return st;
 685     } else if (!ff_guidcmp(mediatype, mediatype_mstvcaption) &&
 686                (!ff_guidcmp(subtype, mediasubtype_teletext) || !ff_guidcmp(subtype, mediasubtype_dtvccdata))) {
 687         st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);
 688         if (!st)
 689             return NULL;
 690         if (ff_guidcmp(formattype, ff_format_none))
 691             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
 692         avio_skip(pb, size);
 693         st->codec->codec_id   = CODEC_ID_DVB_TELETEXT;
 694         return st;
 695     } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_sections) &&
 696                !ff_guidcmp(subtype, mediasubtype_mpeg2_sections)) {
 697         if (ff_guidcmp(formattype, ff_format_none))
 698             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
 699         avio_skip(pb, size);
 700         return NULL;
 701     }
 702
 703     av_log(s, AV_LOG_WARNING, "unknown media type, mediatype:"FF_PRI_GUID
 704                               ", subtype:"FF_PRI_GUID", formattype:"FF_PRI_GUID"\n",
 705                               FF_ARG_GUID(mediatype), FF_ARG_GUID(subtype), FF_ARG_GUID(formattype));
 706     avio_skip(pb, size);
 707     return NULL;
 708 }
 709
 710 enum {
 711     SEEK_TO_DATA = 0,
 712     SEEK_TO_PTS,
 713 };
 714
 715 /**
 716  * Parse WTV chunks
 717  * @param mode SEEK_TO_DATA or SEEK_TO_PTS
 718  * @param seekts timestamp
 719  * @param[out] len Length of data chunk
 720  * @return stream index of data chunk, or <0 on error
 721  */
 722 static int parse_chunks(AVFormatContext *s, int mode, int64_t seekts, int *len_ptr)
 723 {
 724     WtvContext *wtv = s->priv_data;
 725     AVIOContext *pb = wtv->pb;
 726     while (!url_feof(pb)) {
 727         ff_asf_guid g;
 728         int len, sid, consumed;
 729
 730         ff_get_guid(pb, &g);
 731         len = avio_rl32(pb);
 732         if (len < 32)
 733             break;
 734         sid = avio_rl32(pb) & 0x7FFF;
 735         avio_skip(pb, 8);
 736         consumed = 32;
 737
 738         if (!ff_guidcmp(g, ff_stream_guid)) {
 739             if (ff_find_stream_index(s, sid) < 0) {
 740                 ff_asf_guid mediatype, subtype, formattype;
 741                 int size;
 742                 avio_skip(pb, 28);
 743                 ff_get_guid(pb, &mediatype);
 744                 ff_get_guid(pb, &subtype);
 745                 avio_skip(pb, 12);
 746                 ff_get_guid(pb, &formattype);
 747                 size = avio_rl32(pb);
 748                 parse_media_type(s, 0, sid, mediatype, subtype, formattype, size);
 749                 consumed += 92 + size;
 750             }
 751         } else if (!ff_guidcmp(g, stream2_guid)) {
 752             int stream_index = ff_find_stream_index(s, sid);
 753             if (stream_index >= 0 && !((WtvStream*)s->streams[stream_index]->priv_data)->seen_data) {
 754                 ff_asf_guid mediatype, subtype, formattype;
 755                 int size;
 756                 avio_skip(pb, 12);
 757                 ff_get_guid(pb, &mediatype);
 758                 ff_get_guid(pb, &subtype);
 759                 avio_skip(pb, 12);
 760                 ff_get_guid(pb, &formattype);
 761                 size = avio_rl32(pb);
 762                 parse_media_type(s, s->streams[stream_index], sid, mediatype, subtype, formattype, size);
 763                 consumed += 76 + size;
 764             }
 765         } else if (!ff_guidcmp(g, EVENTID_AudioDescriptorSpanningEvent) ||
 766                    !ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
 767                    !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent) ||
 768                    !ff_guidcmp(g, EVENTID_StreamIDSpanningEvent) ||
 769                    !ff_guidcmp(g, EVENTID_SubtitleSpanningEvent) ||
 770                    !ff_guidcmp(g, EVENTID_TeletextSpanningEvent)) {
 771             int stream_index = ff_find_stream_index(s, sid);
 772             if (stream_index >= 0) {
 773                 AVStream *st = s->streams[stream_index];
 774                 uint8_t buf[258];
 775                 const uint8_t *pbuf = buf;
 776                 int buf_size;
 777
 778                 avio_skip(pb, 8);
 779                 consumed += 8;
 780                 if (!ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
 781                     !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent)) {
 782                     avio_skip(pb, 6);
 783                     consumed += 6;
 784                 }
 785
 786                 buf_size = FFMIN(len - consumed, sizeof(buf));
 787                 avio_read(pb, buf, buf_size);
 788                 consumed += buf_size;
 789                 ff_parse_mpeg2_descriptor(s, st, 0, &pbuf, buf + buf_size, 0, 0, 0, 0);
 790             }
 791         } else if (!ff_guidcmp(g, EVENTID_AudioTypeSpanningEvent)) {
 792             int stream_index = ff_find_stream_index(s, sid);
 793             if (stream_index >= 0) {
 794                 AVStream *st = s->streams[stream_index];
 795                 int audio_type;
 796                 avio_skip(pb, 8);
 797                 audio_type = avio_r8(pb);
 798                 if (audio_type == 2)
 799                     st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
 800                 else if (audio_type == 3)
 801                     st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
 802                 consumed += 9;
 803             }
 804         } else if (!ff_guidcmp(g, EVENTID_DVBScramblingControlSpanningEvent)) {
 805             int stream_index = ff_find_stream_index(s, sid);
 806             if (stream_index >= 0) {
 807                 avio_skip(pb, 12);
 808                 if (avio_rl32(pb))
 809                     av_log(s, AV_LOG_WARNING, "DVB scrambled stream detected (st:%d), decoding will likely fail\n", stream_index);
 810                 consumed += 16;
 811             }
 812         } else if (!ff_guidcmp(g, EVENTID_LanguageSpanningEvent)) {
 813             int stream_index = ff_find_stream_index(s, sid);
 814             if (stream_index >= 0) {
 815                 AVStream *st = s->streams[stream_index];
 816                 uint8_t language[4];
 817                 avio_skip(pb, 12);
 818                 avio_read(pb, language, 3);
 819                 if (language[0]) {
 820                     language[3] = 0;
 821                     av_dict_set(&st->metadata, "language", language, 0);
 822                     if (!strcmp(language, "nar") || !strcmp(language, "NAR"))
 823                         st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
 824                 }
 825                 consumed += 15;
 826             }
 827         } else if (!ff_guidcmp(g, ff_timestamp_guid)) {
 828             int stream_index = ff_find_stream_index(s, sid);
 829             if (stream_index >= 0) {
 830                 avio_skip(pb, 8);
 831                 wtv->pts = avio_rl64(pb);
 832                 consumed += 16;
 833                 if (wtv->pts == -1)
 834                     wtv->pts = AV_NOPTS_VALUE;
 835                 else {
 836                     wtv->last_valid_pts = wtv->pts;
 837                     if (wtv->epoch == AV_NOPTS_VALUE || wtv->pts < wtv->epoch)
 838                         wtv->epoch = wtv->pts;
 839                 if (mode == SEEK_TO_PTS && wtv->pts >= seekts) {
 840 #define WTV_PAD8(x) (((x) + 7) & ~7)
 841                     avio_skip(pb, WTV_PAD8(len) - consumed);
 842                     return 0;
 843                 }
 844                 }
 845             }
 846         } else if (!ff_guidcmp(g, ff_data_guid)) {
 847             int stream_index = ff_find_stream_index(s, sid);
 848             if (mode == SEEK_TO_DATA && stream_index >= 0 && len > 32) {
 849                 WtvStream *wst = s->streams[stream_index]->priv_data;
 850                 wst->seen_data = 1;
 851                 if (len_ptr) {
 852                     *len_ptr = len;
 853                 }
 854                 return stream_index;
 855             }
 856         } else if (
 857             !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}) ||
 858             !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}) ||
 859             !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}) ||
 860             !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}) ||
 861             !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}) ||
 862             !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}) ||
 863             !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}) ||
 864             !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}) ||
 865             !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}) ||
 866             !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}) ||
 867             !ff_guidcmp(g, (const ff_asf_guid){0x1E,0xBE,0xC3,0xC5,0x43,0x92,0xDC,0x11,0x85,0xE5,0x00,0x12,0x3F,0x6F,0x73,0xB9}) ||
 868             !ff_guidcmp(g, (const ff_asf_guid){0x3B,0x86,0xA2,0xB1,0xEB,0x1E,0xC3,0x44,0x8C,0x88,0x1C,0xA3,0xFF,0xE3,0xE7,0x6A}) ||
 869             !ff_guidcmp(g, (const ff_asf_guid){0x4E,0x7F,0x4C,0x5B,0xC4,0xD0,0x38,0x4B,0xA8,0x3E,0x21,0x7F,0x7B,0xBF,0x52,0xE7}) ||
 870             !ff_guidcmp(g, (const ff_asf_guid){0x63,0x36,0xEB,0xFE,0xA1,0x7E,0xD9,0x11,0x83,0x08,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
 871             !ff_guidcmp(g, (const ff_asf_guid){0x70,0xE9,0xF1,0xF8,0x89,0xA4,0x4C,0x4D,0x83,0x73,0xB8,0x12,0xE0,0xD5,0xF8,0x1E}) ||
 872             !ff_guidcmp(g, (const ff_asf_guid){0x96,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
 873             !ff_guidcmp(g, (const ff_asf_guid){0x97,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
 874             !ff_guidcmp(g, (const ff_asf_guid){0xA1,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D})) {
 875             //ignore known guids
 876         } else
 877             av_log(s, AV_LOG_WARNING, "unsupported chunk:"FF_PRI_GUID"\n", FF_ARG_GUID(g));
 878
 879         avio_skip(pb, WTV_PAD8(len) - consumed);
 880     }
 881     return AVERROR_EOF;
 882 }
 883
 884 /* declare utf16le strings */
 885 #define _ , 0,
 886 static const uint8_t timeline_le16[] =
 887     {'t'_'i'_'m'_'e'_'l'_'i'_'n'_'e', 0};
 888 static const uint8_t table_0_entries_legacy_attrib_le16[] =
 889     {'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};
 890 static const uint8_t table_0_entries_time_le16[] =
 891     {'t'_'a'_'b'_'l'_'e'_'.'_'0'_'.'_'e'_'n'_'t'_'r'_'i'_'e'_'s'_'.'_'t'_'i'_'m'_'e', 0};
 892 static const uint8_t timeline_table_0_entries_Events_le16[] =
 893     {'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};
 894 #undef _
 895
 896 static int read_header(AVFormatContext *s, AVFormatParameters *ap)
 897 {
 898     WtvContext *wtv = s->priv_data;
 899     int root_sector, root_size;
 900     uint8_t root[WTV_SECTOR_SIZE];
 901     AVIOContext *pb;
 902     int64_t timeline_pos;
 903     int ret;
 904
 905     wtv->epoch          =
 906     wtv->pts            =
 907     wtv->last_valid_pts = AV_NOPTS_VALUE;
 908
 909     /* read root directory sector */
 910     avio_skip(s->pb, 0x30);
 911     root_size = avio_rl32(s->pb);
 912     if (root_size > sizeof(root)) {
 913         av_log(s, AV_LOG_ERROR, "root directory size exceeds sector size\n");
 914         return AVERROR_INVALIDDATA;
 915     }
 916     avio_skip(s->pb, 4);
 917     root_sector = avio_rl32(s->pb);
 918
 919     avio_seek(s->pb, root_sector << WTV_SECTOR_BITS, SEEK_SET);
 920     root_size = avio_read(s->pb, root, root_size);
 921     if (root_size < 0)
 922         return AVERROR_INVALIDDATA;
 923
 924     /* parse chunks up until first data chunk */
 925     wtv->pb = wtvfile_open(s, root, root_size, timeline_le16);
 926     if (!wtv->pb) {
 927         av_log(s, AV_LOG_ERROR, "timeline data missing\n");
 928         return AVERROR_INVALIDDATA;
 929     }
 930
 931     ret = parse_chunks(s, SEEK_TO_DATA, 0, 0);
 932     if (ret < 0)
 933         return ret;
 934     avio_seek(wtv->pb, -32, SEEK_CUR);
 935
 936     timeline_pos = avio_tell(s->pb); // save before opening another file
 937
 938     /* read metadata */
 939     pb = wtvfile_open(s, root, root_size, table_0_entries_legacy_attrib_le16);
 940     if (pb) {
 941         parse_legacy_attrib(s, pb);
 942         wtvfile_close(pb);
 943     }
 944
 945     /* read seek index */
 946     if (s->nb_streams) {
 947         AVStream *st = s->streams[0];
 948         pb = wtvfile_open(s, root, root_size, table_0_entries_time_le16);
 949         if (pb) {
 950             while(1) {
 951                 uint64_t timestamp = avio_rl64(pb);
 952                 uint64_t frame_nb  = avio_rl64(pb);
 953                 if (url_feof(pb))
 954                     break;
 955                 ff_add_index_entry(&wtv->index_entries, &wtv->nb_index_entries, &wtv->index_entries_allocated_size,
 956                                    0, timestamp, frame_nb, 0, AVINDEX_KEYFRAME);
 957             }
 958             wtvfile_close(pb);
 959
 960             if (wtv->nb_index_entries) {
 961                 pb = wtvfile_open(s, root, root_size, timeline_table_0_entries_Events_le16);
 962                 if (pb) {
 963                     int i;
 964                     while (1) {
 965                         uint64_t frame_nb = avio_rl64(pb);
 966                         uint64_t position = avio_rl64(pb);
 967                         if (url_feof(pb))
 968                             break;
 969                         for (i = wtv->nb_index_entries - 1; i >= 0; i--) {
 970                             AVIndexEntry *e = wtv->index_entries + i;
 971                             if (frame_nb > e->size)
 972                                 break;
 973                             if (position > e->pos)
 974                                 e->pos = position;
 975                         }
 976                     }
 977                     wtvfile_close(pb);
 978                     st->duration = wtv->index_entries[wtv->nb_index_entries - 1].timestamp;
 979                 }
 980             }
 981         }
 982     }
 983
 984     avio_seek(s->pb, timeline_pos, SEEK_SET);
 985     return 0;
 986 }
 987
 988 static int read_packet(AVFormatContext *s, AVPacket *pkt)
 989 {
 990     WtvContext *wtv = s->priv_data;
 991     AVIOContext *pb = wtv->pb;
 992     int stream_index, len, ret;
 993
 994     stream_index = parse_chunks(s, SEEK_TO_DATA, 0, &len);
 995     if (stream_index < 0)
 996         return stream_index;
 997
 998     ret = av_get_packet(pb, pkt, len - 32);
 999     if (ret < 0)
1000         return ret;
1001     pkt->stream_index = stream_index;
1002     pkt->pts          = wtv->pts;
1003     avio_skip(pb, WTV_PAD8(len) - len);
1004     return 0;
1005 }
1006
1007 static int read_seek(AVFormatContext *s, int stream_index,
1008                      int64_t ts, int flags)
1009 {
1010     WtvContext *wtv = s->priv_data;
1011     AVIOContext *pb = wtv->pb;
1012     AVStream *st = s->streams[0];
1013     int64_t ts_relative;
1014     int i;
1015
1016     if ((flags & AVSEEK_FLAG_FRAME) || (flags & AVSEEK_FLAG_BYTE))
1017         return AVERROR(ENOSYS);
1018
1019     /* timestamp adjustment is required because wtv->pts values are absolute,
1020      * whereas AVIndexEntry->timestamp values are relative to epoch. */
1021     ts_relative = ts;
1022     if (wtv->epoch != AV_NOPTS_VALUE)
1023         ts_relative -= wtv->epoch;
1024
1025     i = ff_index_search_timestamp(wtv->index_entries, wtv->nb_index_entries, ts_relative, flags);
1026     if (i < 0) {
1027         if (wtv->last_valid_pts == AV_NOPTS_VALUE || ts < wtv->last_valid_pts)
1028             avio_seek(pb, 0, SEEK_SET);
1029         else if (st->duration != AV_NOPTS_VALUE && ts_relative > st->duration && wtv->nb_index_entries)
1030             avio_seek(pb, wtv->index_entries[wtv->nb_index_entries - 1].pos, SEEK_SET);
1031         if (parse_chunks(s, SEEK_TO_PTS, ts, 0) < 0)
1032             return AVERROR(ERANGE);
1033         return 0;
1034     }
1035     wtv->pts = wtv->index_entries[i].timestamp;
1036     if (wtv->epoch != AV_NOPTS_VALUE)
1037         wtv->pts += wtv->epoch;
1038     wtv->last_valid_pts = wtv->pts;
1039     avio_seek(pb, wtv->index_entries[i].pos, SEEK_SET);
1040     return 0;
1041 }
1042
1043 static int read_close(AVFormatContext *s)
1044 {
1045     WtvContext *wtv = s->priv_data;
1046     wtvfile_close(wtv->pb);
1047     return 0;
1048 }
1049
1050 AVInputFormat ff_wtv_demuxer = {
1051     .name           = "wtv",
1052     .long_name      = NULL_IF_CONFIG_SMALL("Windows Television (WTV)"),
1053     .priv_data_size = sizeof(WtvContext),
1054     .read_probe     = read_probe,
1055     .read_header    = read_header,
1056     .read_packet    = read_packet,
1057     .read_seek      = read_seek,
1058     .read_close     = read_close,
1059     .flags          = AVFMT_SHOW_IDS,
1060 };