wtvdec: also support big-sectors when fat depth is zero
[ffmpeg.git] / 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 };