FFmpeg: libavformat/wtvdec.c Source File

00001 /*
00002  * Windows Television (WTV) demuxer
00003  * Copyright (c) 2010-2011 Peter Ross <pross@xvid.org>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00028 #include "libavutil/intreadwrite.h"
00029 #include "libavutil/intfloat_readwrite.h"
00030 #include "avformat.h"
00031 #include "internal.h"
00032 #include "wtv.h"
00033 #include "mpegts.h"
00034 #include <strings.h>
00035 
00036 /* Macros for formating GUIDs */
00037 #define PRI_PRETTY_GUID \
00038     "%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x"
00039 #define ARG_PRETTY_GUID(g) \
00040     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]
00041 #define LEN_PRETTY_GUID 34
00042 
00043 /*
00044  *
00045  * File system routines
00046  *
00047  */
00048 
00049 typedef struct {
00050     AVIOContext *pb_filesystem;  
00052     int sector_bits;     
00053     uint32_t *sectors;   
00054     int nb_sectors;      
00056     int error;
00057     int64_t position;
00058     int64_t length;
00059 } WtvFile;
00060 
00064 static int wtvfile_read_packet(void *opaque, uint8_t *buf, int buf_size)
00065 {
00066     WtvFile *wf = opaque;
00067     AVIOContext *pb = wf->pb_filesystem;
00068     int nread = 0;
00069 
00070     if (wf->error || pb->error)
00071         return -1;
00072     if (wf->position >= wf->length || url_feof(pb))
00073         return 0;
00074 
00075     buf_size = FFMIN(buf_size, wf->length - wf->position);
00076     while(nread < buf_size) {
00077         int n;
00078         int remaining_in_sector = (1 << wf->sector_bits) - (wf->position & ((1 << wf->sector_bits) - 1));
00079         int read_request        = FFMIN(buf_size - nread, remaining_in_sector);
00080 
00081         n = avio_read(pb, buf, read_request);
00082         if (n <= 0)
00083             break;
00084         nread += n;
00085         buf += n;
00086         wf->position += n;
00087         if (n == remaining_in_sector) {
00088             int i = wf->position >> wf->sector_bits;
00089             if (i >= wf->nb_sectors ||
00090                 (wf->sectors[i] != wf->sectors[i - 1] + (1 << (wf->sector_bits - WTV_SECTOR_BITS)) &&
00091                 avio_seek(pb, (int64_t)wf->sectors[i] << WTV_SECTOR_BITS, SEEK_SET) < 0)) {
00092                 wf->error = 1;
00093                 break;
00094             }
00095         }
00096     }
00097     return nread;
00098 }
00099 
00103 static int64_t wtvfile_seek(void *opaque, int64_t offset, int whence)
00104 {
00105     WtvFile *wf = opaque;
00106     AVIOContext *pb = wf->pb_filesystem;
00107 
00108     if (whence == AVSEEK_SIZE)
00109         return wf->length;
00110     else if (whence == SEEK_CUR)
00111         offset = wf->position + offset;
00112     else if (whence == SEEK_END)
00113         offset = wf->length;
00114 
00115     wf->error = offset < 0 || offset >= wf->length ||
00116                 avio_seek(pb, ((int64_t)wf->sectors[offset >> wf->sector_bits] << WTV_SECTOR_BITS)
00117                               + (offset & ((1 << wf->sector_bits) - 1)), SEEK_SET) < 0;
00118     wf->position = offset;
00119     return offset;
00120 }
00121 
00129 static int read_ints(AVIOContext *pb, uint32_t *data, int count)
00130 {
00131     int i, total = 0;
00132     for (i = 0; i < count; i++) {
00133         if ((data[total] = avio_rl32(pb)))
00134            total++;
00135     }
00136     return total;
00137 }
00138 
00146 static AVIOContext * wtvfile_open_sector(int first_sector, uint64_t length, int depth, AVFormatContext *s)
00147 {
00148     AVIOContext *pb;
00149     WtvFile *wf;
00150     uint8_t *buffer;
00151 
00152     if (avio_seek(s->pb, first_sector << WTV_SECTOR_BITS, SEEK_SET) < 0)
00153         return NULL;
00154 
00155     wf = av_mallocz(sizeof(WtvFile));
00156     if (!wf)
00157         return NULL;
00158 
00159     if (depth == 0) {
00160         wf->sectors = av_malloc(sizeof(uint32_t));
00161         if (!wf->sectors) {
00162             av_free(wf);
00163             return NULL;
00164         }
00165         wf->sectors[0]  = first_sector;
00166         wf->nb_sectors  = 1;
00167     } else if (depth == 1) {
00168         wf->sectors = av_malloc(WTV_SECTOR_SIZE);
00169         if (!wf->sectors) {
00170             av_free(wf);
00171             return NULL;
00172         }
00173         wf->nb_sectors  = read_ints(s->pb, wf->sectors, WTV_SECTOR_SIZE / 4);
00174     } else if (depth == 2) {
00175         uint32_t sectors1[WTV_SECTOR_SIZE / 4];
00176         int nb_sectors1 = read_ints(s->pb, sectors1, WTV_SECTOR_SIZE / 4);
00177         int i;
00178 
00179         wf->sectors = av_malloc(nb_sectors1 << WTV_SECTOR_BITS);
00180         if (!wf->sectors) {
00181             av_free(wf);
00182             return NULL;
00183         }
00184         wf->nb_sectors = 0;
00185         for (i = 0; i < nb_sectors1; i++) {
00186             if (avio_seek(s->pb, (int64_t)sectors1[i] << WTV_SECTOR_BITS, SEEK_SET) < 0)
00187                 break;
00188             wf->nb_sectors += read_ints(s->pb, wf->sectors + i * WTV_SECTOR_SIZE / 4, WTV_SECTOR_SIZE / 4);
00189         }
00190     } else {
00191         av_log(s, AV_LOG_ERROR, "unsupported file allocation table depth (0x%x)\n", depth);
00192         av_free(wf);
00193         return NULL;
00194     }
00195     wf->sector_bits = length & (1ULL<<63) ? WTV_SECTOR_BITS : WTV_BIGSECTOR_BITS;
00196 
00197     if (!wf->nb_sectors) {
00198         av_free(wf->sectors);
00199         av_free(wf);
00200         return NULL;
00201     }
00202 
00203     /* check length */
00204     length &= 0xFFFFFFFFFFFF;
00205     if (length > ((int64_t)wf->nb_sectors << wf->sector_bits)) {
00206         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);
00207         length = (int64_t)wf->nb_sectors <<  wf->sector_bits;
00208     }
00209     wf->length = length;
00210 
00211     /* seek to intial sector */
00212     wf->position = 0;
00213     if (avio_seek(s->pb, (int64_t)wf->sectors[0] << WTV_SECTOR_BITS, SEEK_SET) < 0) {
00214         av_free(wf->sectors);
00215         av_free(wf);
00216         return NULL;
00217     }
00218 
00219     wf->pb_filesystem = s->pb;
00220     buffer = av_malloc(1 << wf->sector_bits);
00221     if (!buffer) {
00222         av_free(wf->sectors);
00223         av_free(wf);
00224         return NULL;
00225     }
00226 
00227     pb = avio_alloc_context(buffer, 1 << wf->sector_bits, 0, wf,
00228                            wtvfile_read_packet, NULL, wtvfile_seek);
00229     if (!pb) {
00230         av_free(buffer);
00231         av_free(wf->sectors);
00232         av_free(wf);
00233     }
00234     return pb;
00235 }
00236 
00245 static AVIOContext * wtvfile_open2(AVFormatContext *s, const uint8_t *buf, int buf_size, const uint8_t *filename, int filename_size)
00246 {
00247     const uint8_t *buf_end = buf + buf_size;
00248 
00249     while(buf + 48 <= buf_end) {
00250         int dir_length, name_size, first_sector, depth;
00251         uint64_t file_length;
00252         const uint8_t *name;
00253         if (ff_guidcmp(buf, ff_dir_entry_guid)) {
00254             av_log(s, AV_LOG_ERROR, "unknown guid "FF_PRI_GUID", expected dir_entry_guid; "
00255                    "remaining directory entries ignored\n", FF_ARG_GUID(buf));
00256             break;
00257         }
00258         dir_length  = AV_RL16(buf + 16);
00259         file_length = AV_RL64(buf + 24);
00260         name_size   = 2 * AV_RL32(buf + 32);
00261         if (buf + 48 + name_size > buf_end) {
00262             av_log(s, AV_LOG_ERROR, "filename exceeds buffer size; remaining directory entries ignored\n");
00263             break;
00264         }
00265         first_sector = AV_RL32(buf + 40 + name_size);
00266         depth        = AV_RL32(buf + 44 + name_size);
00267 
00268         /* compare file name; test optional null terminator */
00269         name = buf + 40;
00270         if (name_size >= filename_size &&
00271             !memcmp(name, filename, filename_size) &&
00272             (name_size < filename_size + 2 || !AV_RN16(name + filename_size)))
00273             return wtvfile_open_sector(first_sector, file_length, depth, s);
00274 
00275         buf += dir_length;
00276     }
00277     return 0;
00278 }
00279 
00280 #define wtvfile_open(s, buf, buf_size, filename) \
00281     wtvfile_open2(s, buf, buf_size, filename, sizeof(filename))
00282 
00286 static void wtvfile_close(AVIOContext *pb)
00287 {
00288     WtvFile *wf = pb->opaque;
00289     av_free(wf->sectors);
00290     av_free(pb);
00291 }
00292 
00293 /*
00294  *
00295  * Main demuxer
00296  *
00297  */
00298 
00299 typedef struct {
00300     int seen_data;
00301 } WtvStream;
00302 
00303 typedef struct {
00304     AVIOContext *pb;       
00305     int64_t epoch;
00306     int64_t pts;             
00307     int64_t last_valid_pts;  
00309     /* maintain private seek index, as the AVIndexEntry->pos is relative to the
00310        start of the 'timeline' file, not the file system (AVFormatContext->pb) */
00311     AVIndexEntry *index_entries;
00312     int nb_index_entries;
00313     unsigned int index_entries_allocated_size;
00314 } WtvContext;
00315 
00316 /* WTV GUIDs */
00317 static const ff_asf_guid EVENTID_SubtitleSpanningEvent =
00318     {0x48,0xC0,0xCE,0x5D,0xB9,0xD0,0x63,0x41,0x87,0x2C,0x4F,0x32,0x22,0x3B,0xE8,0x8A};
00319 static const ff_asf_guid EVENTID_LanguageSpanningEvent =
00320     {0x6D,0x66,0x92,0xE2,0x02,0x9C,0x8D,0x44,0xAA,0x8D,0x78,0x1A,0x93,0xFD,0xC3,0x95};
00321 static const ff_asf_guid EVENTID_AudioDescriptorSpanningEvent =
00322     {0x1C,0xD4,0x7B,0x10,0xDA,0xA6,0x91,0x46,0x83,0x69,0x11,0xB2,0xCD,0xAA,0x28,0x8E};
00323 static const ff_asf_guid EVENTID_CtxADescriptorSpanningEvent =
00324     {0xE6,0xA2,0xB4,0x3A,0x47,0x42,0x34,0x4B,0x89,0x6C,0x30,0xAF,0xA5,0xD2,0x1C,0x24};
00325 static const ff_asf_guid EVENTID_CSDescriptorSpanningEvent =
00326     {0xD9,0x79,0xE7,0xEf,0xF0,0x97,0x86,0x47,0x80,0x0D,0x95,0xCF,0x50,0x5D,0xDC,0x66};
00327 static const ff_asf_guid EVENTID_DVBScramblingControlSpanningEvent =
00328     {0xC4,0xE1,0xD4,0x4B,0xA1,0x90,0x09,0x41,0x82,0x36,0x27,0xF0,0x0E,0x7D,0xCC,0x5B};
00329 static const ff_asf_guid EVENTID_StreamIDSpanningEvent =
00330     {0x68,0xAB,0xF1,0xCA,0x53,0xE1,0x41,0x4D,0xA6,0xB3,0xA7,0xC9,0x98,0xDB,0x75,0xEE};
00331 static const ff_asf_guid EVENTID_TeletextSpanningEvent =
00332     {0x50,0xD9,0x99,0x95,0x33,0x5F,0x17,0x46,0xAF,0x7C,0x1E,0x54,0xB5,0x10,0xDA,0xA3};
00333 static const ff_asf_guid EVENTID_AudioTypeSpanningEvent =
00334     {0xBE,0xBF,0x1C,0x50,0x49,0xB8,0xCE,0x42,0x9B,0xE9,0x3D,0xB8,0x69,0xFB,0x82,0xB3};
00335 
00336 /* Windows media GUIDs */
00337 
00338 /* Media types */
00339 static const ff_asf_guid mediasubtype_mpeg1payload =
00340     {0x81,0xEB,0x36,0xE4,0x4F,0x52,0xCE,0x11,0x9F,0x53,0x00,0x20,0xAF,0x0B,0xA7,0x70};
00341 static const ff_asf_guid mediatype_mpeg2_sections =
00342     {0x6C,0x17,0x5F,0x45,0x06,0x4B,0xCE,0x47,0x9A,0xEF,0x8C,0xAE,0xF7,0x3D,0xF7,0xB5};
00343 static const ff_asf_guid mediatype_mpeg2_pes =
00344     {0x20,0x80,0x6D,0xE0,0x46,0xDB,0xCF,0x11,0xB4,0xD1,0x00,0x80,0x5F,0x6C,0xBB,0xEA};
00345 static const ff_asf_guid mediatype_mstvcaption =
00346     {0x89,0x8A,0x8B,0xB8,0x49,0xB0,0x80,0x4C,0xAD,0xCF,0x58,0x98,0x98,0x5E,0x22,0xC1};
00347 
00348 /* Media subtypes */
00349 static const ff_asf_guid mediasubtype_dvb_subtitle =
00350     {0xC3,0xCB,0xFF,0x34,0xB3,0xD5,0x71,0x41,0x90,0x02,0xD4,0xC6,0x03,0x01,0x69,0x7F};
00351 static const ff_asf_guid mediasubtype_teletext =
00352     {0xE3,0x76,0x2A,0xF7,0x0A,0xEB,0xD0,0x11,0xAC,0xE4,0x00,0x00,0xC0,0xCC,0x16,0xBA};
00353 static const ff_asf_guid mediasubtype_dtvccdata =
00354     {0xAA,0xDD,0x2A,0xF5,0xF0,0x36,0xF5,0x43,0x95,0xEA,0x6D,0x86,0x64,0x84,0x26,0x2A};
00355 static const ff_asf_guid mediasubtype_mpeg2_sections =
00356     {0x79,0x85,0x9F,0x4A,0xF8,0x6B,0x92,0x43,0x8A,0x6D,0xD2,0xDD,0x09,0xFA,0x78,0x61};
00357 
00358 /* Formats */
00359 static const ff_asf_guid format_videoinfo2 =
00360     {0xA0,0x76,0x2A,0xF7,0x0A,0xEB,0xD0,0x11,0xAC,0xE4,0x00,0x00,0xC0,0xCC,0x16,0xBA};
00361 
00362 static int read_probe(AVProbeData *p)
00363 {
00364     return ff_guidcmp(p->buf, ff_wtv_guid) ? 0 : AVPROBE_SCORE_MAX;
00365 }
00366 
00370 static void filetime_to_iso8601(char *buf, int buf_size, int64_t value)
00371 {
00372     time_t t = (value / 10000000LL) - 11644473600LL;
00373     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
00374 }
00375 
00379 static void crazytime_to_iso8601(char *buf, int buf_size, int64_t value)
00380 {
00381     time_t t = (value / 10000000LL) - 719162LL*86400LL;
00382     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
00383 }
00384 
00389 static int oledate_to_iso8601(char *buf, int buf_size, int64_t value)
00390 {
00391     time_t t = (av_int2dbl(value) - 25569.0) * 86400;
00392     struct tm *result= gmtime(&t);
00393     if (!result)
00394         return -1;
00395     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", result);
00396     return 0;
00397 }
00398 
00399 static void get_attachment(AVFormatContext *s, AVIOContext *pb, int length)
00400 {
00401     char mime[1024];
00402     char description[1024];
00403     unsigned int filesize;
00404     AVStream *st;
00405     int64_t pos = avio_tell(pb);
00406 
00407     avio_get_str16le(pb, INT_MAX, mime, sizeof(mime));
00408     if (strcmp(mime, "image/jpeg"))
00409         goto done;
00410 
00411     avio_r8(pb);
00412     avio_get_str16le(pb, INT_MAX, description, sizeof(description));
00413     filesize = avio_rl32(pb);
00414     if (!filesize)
00415         goto done;
00416 
00417     st = avformat_new_stream(s, NULL);
00418     if (!st)
00419         goto done;
00420     av_dict_set(&st->metadata, "title", description, 0);
00421     st->codec->codec_id   = CODEC_ID_MJPEG;
00422     st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
00423     st->codec->extradata  = av_mallocz(filesize);
00424     if (!st->codec->extradata)
00425         goto done;
00426     st->codec->extradata_size = filesize;
00427     avio_read(pb, st->codec->extradata, filesize);
00428 done:
00429     avio_seek(pb, pos + length, SEEK_SET);
00430 }
00431 
00432 static void get_tag(AVFormatContext *s, AVIOContext *pb, const char *key, int type, int length)
00433 {
00434     int buf_size = FFMAX(2*length, LEN_PRETTY_GUID) + 1;
00435     char *buf = av_malloc(buf_size);
00436     if (!buf)
00437         return;
00438 
00439     if (type == 0 && length == 4) {
00440         snprintf(buf, buf_size, "%"PRIi32, avio_rl32(pb));
00441     } else if (type == 1) {
00442         avio_get_str16le(pb, length, buf, buf_size);
00443         if (!strlen(buf)) {
00444            av_free(buf);
00445            return;
00446         }
00447     } else if (type == 3 && length == 4) {
00448         strcpy(buf, avio_rl32(pb) ? "true" : "false");
00449     } else if (type == 4 && length == 8) {
00450         int64_t num = avio_rl64(pb);
00451         if (!strcmp(key, "WM/EncodingTime") ||
00452             !strcmp(key, "WM/MediaOriginalBroadcastDateTime"))
00453             filetime_to_iso8601(buf, buf_size, num);
00454         else if (!strcmp(key, "WM/WMRVEncodeTime") ||
00455                  !strcmp(key, "WM/WMRVEndTime"))
00456             crazytime_to_iso8601(buf, buf_size, num);
00457         else if (!strcmp(key, "WM/WMRVExpirationDate")) {
00458             if (oledate_to_iso8601(buf, buf_size, num) < 0 ) {
00459                 av_free(buf);
00460                 return;
00461             }
00462         } else if (!strcmp(key, "WM/WMRVBitrate"))
00463             snprintf(buf, buf_size, "%f", av_int2dbl(num));
00464         else
00465             snprintf(buf, buf_size, "%"PRIi64, num);
00466     } else if (type == 5 && length == 2) {
00467         snprintf(buf, buf_size, "%"PRIi16, avio_rl16(pb));
00468     } else if (type == 6 && length == 16) {
00469         ff_asf_guid guid;
00470         avio_read(pb, guid, 16);
00471         snprintf(buf, buf_size, PRI_PRETTY_GUID, ARG_PRETTY_GUID(guid));
00472     } else if (type == 2 && !strcmp(key, "WM/Picture")) {
00473         get_attachment(s, pb, length);
00474         av_freep(&buf);
00475         return;
00476     } else {
00477         av_freep(&buf);
00478         av_log(s, AV_LOG_WARNING, "unsupported metadata entry; key:%s, type:%d, length:0x%x\n", key, type, length);
00479         avio_skip(pb, length);
00480         return;
00481     }
00482 
00483     av_dict_set(&s->metadata, key, buf, 0);
00484     av_freep(&buf);
00485 }
00486 
00490 static void parse_legacy_attrib(AVFormatContext *s, AVIOContext *pb)
00491 {
00492     ff_asf_guid guid;
00493     int length, type;
00494     while(!url_feof(pb)) {
00495         char key[1024];
00496         ff_get_guid(pb, &guid);
00497         type   = avio_rl32(pb);
00498         length = avio_rl32(pb);
00499         if (!length)
00500             break;
00501         if (ff_guidcmp(&guid, ff_metadata_guid)) {
00502             av_log(s, AV_LOG_WARNING, "unknown guid "FF_PRI_GUID", expected metadata_guid; "
00503                    "remaining metadata entries ignored\n", FF_ARG_GUID(guid));
00504             break;
00505         }
00506         avio_get_str16le(pb, INT_MAX, key, sizeof(key));
00507         get_tag(s, pb, key, type, length);
00508     }
00509 
00510     ff_metadata_conv(&s->metadata, NULL, ff_asf_metadata_conv);
00511 }
00512 
00517 static int parse_videoinfoheader2(AVFormatContext *s, AVStream *st)
00518 {
00519     WtvContext *wtv = s->priv_data;
00520     AVIOContext *pb = wtv->pb;
00521 
00522     avio_skip(pb, 72);  // picture aspect ratio is unreliable
00523     ff_get_bmp_header(pb, st);
00524 
00525     return 72 + 40;
00526 }
00527 
00531 static void parse_mpeg1waveformatex(AVStream *st)
00532 {
00533     /* fwHeadLayer */
00534     switch (AV_RL16(st->codec->extradata)) {
00535     case 0x0001 : st->codec->codec_id = CODEC_ID_MP1; break;
00536     case 0x0002 : st->codec->codec_id = CODEC_ID_MP2; break;
00537     case 0x0004 : st->codec->codec_id = CODEC_ID_MP3; break;
00538     }
00539 
00540     st->codec->bit_rate = AV_RL32(st->codec->extradata + 2); /* dwHeadBitrate */
00541 
00542     /* dwHeadMode */
00543     switch (AV_RL16(st->codec->extradata + 6)) {
00544     case 1 : case 2 : case 4 : st->codec->channels = 2; break;
00545     case 8 :                   st->codec->channels = 1; break;
00546     }
00547 }
00548 
00554 static AVStream * new_stream(AVFormatContext *s, AVStream *st, int sid, int codec_type)
00555 {
00556     if (st) {
00557         if (st->codec->extradata) {
00558             av_freep(&st->codec->extradata);
00559             st->codec->extradata_size = 0;
00560         }
00561     } else {
00562         WtvStream *wst = av_mallocz(sizeof(WtvStream));
00563         if (!wst)
00564             return NULL;
00565         st = avformat_new_stream(s, NULL);
00566         if (!st)
00567             return NULL;
00568         st->id = sid;
00569         st->priv_data = wst;
00570     }
00571     st->codec->codec_type = codec_type;
00572     st->need_parsing      = AVSTREAM_PARSE_FULL;
00573     avpriv_set_pts_info(st, 64, 1, 10000000);
00574     return st;
00575 }
00576 
00586 static AVStream * parse_media_type(AVFormatContext *s, AVStream *st, int sid,
00587                                    ff_asf_guid mediatype, ff_asf_guid subtype,
00588                                    ff_asf_guid formattype, int size)
00589 {
00590     WtvContext *wtv = s->priv_data;
00591     AVIOContext *pb = wtv->pb;
00592     if (!ff_guidcmp(subtype, ff_mediasubtype_cpfilters_processed) &&
00593         !ff_guidcmp(formattype, ff_format_cpfilters_processed)) {
00594         ff_asf_guid actual_subtype;
00595         ff_asf_guid actual_formattype;
00596 
00597         if (size < 32) {
00598             av_log(s, AV_LOG_WARNING, "format buffer size underflow\n");
00599             avio_skip(pb, size);
00600             return NULL;
00601         }
00602 
00603         avio_skip(pb, size - 32);
00604         ff_get_guid(pb, &actual_subtype);
00605         ff_get_guid(pb, &actual_formattype);
00606         avio_seek(pb, -size, SEEK_CUR);
00607 
00608         st = parse_media_type(s, st, sid, mediatype, actual_subtype, actual_formattype, size - 32);
00609         avio_skip(pb, 32);
00610         return st;
00611     } else if (!ff_guidcmp(mediatype, ff_mediatype_audio)) {
00612         st = new_stream(s, st, sid, AVMEDIA_TYPE_AUDIO);
00613         if (!st)
00614             return NULL;
00615         if (!ff_guidcmp(formattype, ff_format_waveformatex)) {
00616             int ret = ff_get_wav_header(pb, st->codec, size);
00617             if (ret < 0)
00618                 return NULL;
00619         } else {
00620             if (ff_guidcmp(formattype, ff_format_none))
00621                 av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
00622             avio_skip(pb, size);
00623         }
00624 
00625         if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {
00626             st->codec->codec_id = ff_wav_codec_get_id(AV_RL32(subtype), st->codec->bits_per_coded_sample);
00627         } else if (!ff_guidcmp(subtype, mediasubtype_mpeg1payload)) {
00628             if (st->codec->extradata && st->codec->extradata_size >= 22)
00629                 parse_mpeg1waveformatex(st);
00630             else
00631                 av_log(s, AV_LOG_WARNING, "MPEG1WAVEFORMATEX underflow\n");
00632         } else {
00633             st->codec->codec_id = ff_codec_guid_get_id(ff_codec_wav_guids, subtype);
00634             if (st->codec->codec_id == CODEC_ID_NONE)
00635                 av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID"\n", FF_ARG_GUID(subtype));
00636         }
00637         return st;
00638     } else if (!ff_guidcmp(mediatype, ff_mediatype_video)) {
00639         st = new_stream(s, st, sid, AVMEDIA_TYPE_VIDEO);
00640         if (!st)
00641             return NULL;
00642         if (!ff_guidcmp(formattype, format_videoinfo2)) {
00643             int consumed = parse_videoinfoheader2(s, st);
00644             avio_skip(pb, FFMAX(size - consumed, 0));
00645         } else if (!ff_guidcmp(formattype, ff_format_mpeg2_video)) {
00646             int consumed = parse_videoinfoheader2(s, st);
00647             avio_skip(pb, FFMAX(size - consumed, 0));
00648         } else {
00649             if (ff_guidcmp(formattype, ff_format_none))
00650                 av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
00651             avio_skip(pb, size);
00652         }
00653 
00654         if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {
00655             st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, AV_RL32(subtype));
00656         } else {
00657             st->codec->codec_id = ff_codec_guid_get_id(ff_video_guids, subtype);
00658         }
00659         if (st->codec->codec_id == CODEC_ID_NONE)
00660             av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID"\n", FF_ARG_GUID(subtype));
00661         return st;
00662     } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_pes) &&
00663                !ff_guidcmp(subtype, mediasubtype_dvb_subtitle)) {
00664         st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);
00665         if (!st)
00666             return NULL;
00667         if (ff_guidcmp(formattype, ff_format_none))
00668             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
00669         avio_skip(pb, size);
00670         st->codec->codec_id = CODEC_ID_DVB_SUBTITLE;
00671         return st;
00672     } else if (!ff_guidcmp(mediatype, mediatype_mstvcaption) &&
00673                (!ff_guidcmp(subtype, mediasubtype_teletext) || !ff_guidcmp(subtype, mediasubtype_dtvccdata))) {
00674         st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);
00675         if (!st)
00676             return NULL;
00677         if (ff_guidcmp(formattype, ff_format_none))
00678             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
00679         avio_skip(pb, size);
00680         st->codec->codec_id   = CODEC_ID_DVB_TELETEXT;
00681         return st;
00682     } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_sections) &&
00683                !ff_guidcmp(subtype, mediasubtype_mpeg2_sections)) {
00684         if (ff_guidcmp(formattype, ff_format_none))
00685             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
00686         avio_skip(pb, size);
00687         return NULL;
00688     }
00689 
00690     av_log(s, AV_LOG_WARNING, "unknown media type, mediatype:"FF_PRI_GUID
00691                               ", subtype:"FF_PRI_GUID", formattype:"FF_PRI_GUID"\n",
00692                               FF_ARG_GUID(mediatype), FF_ARG_GUID(subtype), FF_ARG_GUID(formattype));
00693     avio_skip(pb, size);
00694     return NULL;
00695 }
00696 
00697 enum {
00698     SEEK_TO_DATA = 0,
00699     SEEK_TO_PTS,
00700 };
00701 
00709 static int parse_chunks(AVFormatContext *s, int mode, int64_t seekts, int *len_ptr)
00710 {
00711     WtvContext *wtv = s->priv_data;
00712     AVIOContext *pb = wtv->pb;
00713     while (!url_feof(pb)) {
00714         ff_asf_guid g;
00715         int len, sid, consumed;
00716 
00717         ff_get_guid(pb, &g);
00718         len = avio_rl32(pb);
00719         if (len < 32)
00720             break;
00721         sid = avio_rl32(pb) & 0x7FFF;
00722         avio_skip(pb, 8);
00723         consumed = 32;
00724 
00725         if (!ff_guidcmp(g, ff_stream_guid)) {
00726             if (ff_find_stream_index(s, sid) < 0) {
00727                 ff_asf_guid mediatype, subtype, formattype;
00728                 int size;
00729                 avio_skip(pb, 28);
00730                 ff_get_guid(pb, &mediatype);
00731                 ff_get_guid(pb, &subtype);
00732                 avio_skip(pb, 12);
00733                 ff_get_guid(pb, &formattype);
00734                 size = avio_rl32(pb);
00735                 parse_media_type(s, 0, sid, mediatype, subtype, formattype, size);
00736                 consumed += 92 + size;
00737             }
00738         } else if (!ff_guidcmp(g, ff_stream2_guid)) {
00739             int stream_index = ff_find_stream_index(s, sid);
00740             if (stream_index >= 0 && !((WtvStream*)s->streams[stream_index]->priv_data)->seen_data) {
00741                 ff_asf_guid mediatype, subtype, formattype;
00742                 int size;
00743                 avio_skip(pb, 12);
00744                 ff_get_guid(pb, &mediatype);
00745                 ff_get_guid(pb, &subtype);
00746                 avio_skip(pb, 12);
00747                 ff_get_guid(pb, &formattype);
00748                 size = avio_rl32(pb);
00749                 parse_media_type(s, s->streams[stream_index], sid, mediatype, subtype, formattype, size);
00750                 consumed += 76 + size;
00751             }
00752         } else if (!ff_guidcmp(g, EVENTID_AudioDescriptorSpanningEvent) ||
00753                    !ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
00754                    !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent) ||
00755                    !ff_guidcmp(g, EVENTID_StreamIDSpanningEvent) ||
00756                    !ff_guidcmp(g, EVENTID_SubtitleSpanningEvent) ||
00757                    !ff_guidcmp(g, EVENTID_TeletextSpanningEvent)) {
00758             int stream_index = ff_find_stream_index(s, sid);
00759             if (stream_index >= 0) {
00760                 AVStream *st = s->streams[stream_index];
00761                 uint8_t buf[258];
00762                 const uint8_t *pbuf = buf;
00763                 int buf_size;
00764 
00765                 avio_skip(pb, 8);
00766                 consumed += 8;
00767                 if (!ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
00768                     !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent)) {
00769                     avio_skip(pb, 6);
00770                     consumed += 6;
00771                 }
00772 
00773                 buf_size = FFMIN(len - consumed, sizeof(buf));
00774                 avio_read(pb, buf, buf_size);
00775                 consumed += buf_size;
00776                 ff_parse_mpeg2_descriptor(s, st, 0, &pbuf, buf + buf_size, NULL, 0, 0, NULL);
00777             }
00778         } else if (!ff_guidcmp(g, EVENTID_AudioTypeSpanningEvent)) {
00779             int stream_index = ff_find_stream_index(s, sid);
00780             if (stream_index >= 0) {
00781                 AVStream *st = s->streams[stream_index];
00782                 int audio_type;
00783                 avio_skip(pb, 8);
00784                 audio_type = avio_r8(pb);
00785                 if (audio_type == 2)
00786                     st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
00787                 else if (audio_type == 3)
00788                     st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
00789                 consumed += 9;
00790             }
00791         } else if (!ff_guidcmp(g, EVENTID_DVBScramblingControlSpanningEvent)) {
00792             int stream_index = ff_find_stream_index(s, sid);
00793             if (stream_index >= 0) {
00794                 avio_skip(pb, 12);
00795                 if (avio_rl32(pb))
00796                     av_log(s, AV_LOG_WARNING, "DVB scrambled stream detected (st:%d), decoding will likely fail\n", stream_index);
00797                 consumed += 16;
00798             }
00799         } else if (!ff_guidcmp(g, EVENTID_LanguageSpanningEvent)) {
00800             int stream_index = ff_find_stream_index(s, sid);
00801             if (stream_index >= 0) {
00802                 AVStream *st = s->streams[stream_index];
00803                 uint8_t language[4];
00804                 avio_skip(pb, 12);
00805                 avio_read(pb, language, 3);
00806                 if (language[0]) {
00807                     language[3] = 0;
00808                     av_dict_set(&st->metadata, "language", language, 0);
00809                     if (!strcmp(language, "nar") || !strcmp(language, "NAR"))
00810                         st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
00811                 }
00812                 consumed += 15;
00813             }
00814         } else if (!ff_guidcmp(g, ff_timestamp_guid)) {
00815             int stream_index = ff_find_stream_index(s, sid);
00816             if (stream_index >= 0) {
00817                 avio_skip(pb, 8);
00818                 wtv->pts = avio_rl64(pb);
00819                 consumed += 16;
00820                 if (wtv->pts == -1)
00821                     wtv->pts = AV_NOPTS_VALUE;
00822                 else {
00823                     wtv->last_valid_pts = wtv->pts;
00824                     if (wtv->epoch == AV_NOPTS_VALUE || wtv->pts < wtv->epoch)
00825                         wtv->epoch = wtv->pts;
00826                 if (mode == SEEK_TO_PTS && wtv->pts >= seekts) {
00827                     avio_skip(pb, WTV_PAD8(len) - consumed);
00828                     return 0;
00829                 }
00830                 }
00831             }
00832         } else if (!ff_guidcmp(g, ff_data_guid)) {
00833             int stream_index = ff_find_stream_index(s, sid);
00834             if (mode == SEEK_TO_DATA && stream_index >= 0 && len > 32) {
00835                 WtvStream *wst = s->streams[stream_index]->priv_data;
00836                 wst->seen_data = 1;
00837                 if (len_ptr) {
00838                     *len_ptr = len;
00839                 }
00840                 return stream_index;
00841             }
00842         } else if (
00843             !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}) ||
00844             !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}) ||
00845             !ff_guidcmp(g, /* DSATTRIB_TRANSPORT_PROPERTIES */ ff_DSATTRIB_TRANSPORT_PROPERTIES) ||
00846             !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}) ||
00847             !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}) ||
00848             !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}) ||
00849             !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}) ||
00850             !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}) ||
00851             !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}) ||
00852             !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}) ||
00853             !ff_guidcmp(g, (const ff_asf_guid){0x1E,0xBE,0xC3,0xC5,0x43,0x92,0xDC,0x11,0x85,0xE5,0x00,0x12,0x3F,0x6F,0x73,0xB9}) ||
00854             !ff_guidcmp(g, (const ff_asf_guid){0x3B,0x86,0xA2,0xB1,0xEB,0x1E,0xC3,0x44,0x8C,0x88,0x1C,0xA3,0xFF,0xE3,0xE7,0x6A}) ||
00855             !ff_guidcmp(g, (const ff_asf_guid){0x4E,0x7F,0x4C,0x5B,0xC4,0xD0,0x38,0x4B,0xA8,0x3E,0x21,0x7F,0x7B,0xBF,0x52,0xE7}) ||
00856             !ff_guidcmp(g, (const ff_asf_guid){0x63,0x36,0xEB,0xFE,0xA1,0x7E,0xD9,0x11,0x83,0x08,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
00857             !ff_guidcmp(g, (const ff_asf_guid){0x70,0xE9,0xF1,0xF8,0x89,0xA4,0x4C,0x4D,0x83,0x73,0xB8,0x12,0xE0,0xD5,0xF8,0x1E}) ||
00858             !ff_guidcmp(g, (const ff_asf_guid){0x96,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
00859             !ff_guidcmp(g, (const ff_asf_guid){0x97,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
00860             !ff_guidcmp(g, (const ff_asf_guid){0xA1,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
00861             !ff_guidcmp(g, (const ff_asf_guid){0xF7,0x10,0x02,0xB9,0xEE,0x7C,0xED,0x4E,0xBD,0x7F,0x05,0x40,0x35,0x86,0x18,0xA1})) {
00862             //ignore known guids
00863         } else
00864             av_log(s, AV_LOG_WARNING, "unsupported chunk:"FF_PRI_GUID"\n", FF_ARG_GUID(g));
00865 
00866         avio_skip(pb, WTV_PAD8(len) - consumed);
00867     }
00868     return AVERROR_EOF;
00869 }
00870 
00871 static int read_header(AVFormatContext *s, AVFormatParameters *ap)
00872 {
00873     WtvContext *wtv = s->priv_data;
00874     int root_sector, root_size;
00875     uint8_t root[WTV_SECTOR_SIZE];
00876     AVIOContext *pb;
00877     int64_t timeline_pos;
00878     int ret;
00879 
00880     wtv->epoch          =
00881     wtv->pts            =
00882     wtv->last_valid_pts = AV_NOPTS_VALUE;
00883 
00884     /* read root directory sector */
00885     avio_skip(s->pb, 0x30);
00886     root_size = avio_rl32(s->pb);
00887     if (root_size > sizeof(root)) {
00888         av_log(s, AV_LOG_ERROR, "root directory size exceeds sector size\n");
00889         return AVERROR_INVALIDDATA;
00890     }
00891     avio_skip(s->pb, 4);
00892     root_sector = avio_rl32(s->pb);
00893 
00894     avio_seek(s->pb, root_sector << WTV_SECTOR_BITS, SEEK_SET);
00895     root_size = avio_read(s->pb, root, root_size);
00896     if (root_size < 0)
00897         return AVERROR_INVALIDDATA;
00898 
00899     /* parse chunks up until first data chunk */
00900     wtv->pb = wtvfile_open(s, root, root_size, ff_timeline_le16);
00901     if (!wtv->pb) {
00902         av_log(s, AV_LOG_ERROR, "timeline data missing\n");
00903         return AVERROR_INVALIDDATA;
00904     }
00905 
00906     ret = parse_chunks(s, SEEK_TO_DATA, 0, 0);
00907     if (ret < 0)
00908         return ret;
00909     avio_seek(wtv->pb, -32, SEEK_CUR);
00910 
00911     timeline_pos = avio_tell(s->pb); // save before opening another file
00912 
00913     /* read metadata */
00914     pb = wtvfile_open(s, root, root_size, ff_table_0_entries_legacy_attrib_le16);
00915     if (pb) {
00916         parse_legacy_attrib(s, pb);
00917         wtvfile_close(pb);
00918     }
00919 
00920     /* read seek index */
00921     if (s->nb_streams) {
00922         AVStream *st = s->streams[0];
00923         pb = wtvfile_open(s, root, root_size, ff_table_0_entries_time_le16);
00924         if (pb) {
00925             while(1) {
00926                 uint64_t timestamp = avio_rl64(pb);
00927                 uint64_t frame_nb  = avio_rl64(pb);
00928                 if (url_feof(pb))
00929                     break;
00930                 ff_add_index_entry(&wtv->index_entries, &wtv->nb_index_entries, &wtv->index_entries_allocated_size,
00931                                    0, timestamp, frame_nb, 0, AVINDEX_KEYFRAME);
00932             }
00933             wtvfile_close(pb);
00934 
00935             if (wtv->nb_index_entries) {
00936                 pb = wtvfile_open(s, root, root_size, ff_timeline_table_0_entries_Events_le16);
00937                 if (pb) {
00938                     int i;
00939                     while (1) {
00940                         uint64_t frame_nb = avio_rl64(pb);
00941                         uint64_t position = avio_rl64(pb);
00942                         if (url_feof(pb))
00943                             break;
00944                         for (i = wtv->nb_index_entries - 1; i >= 0; i--) {
00945                             AVIndexEntry *e = wtv->index_entries + i;
00946                             if (frame_nb > e->size)
00947                                 break;
00948                             if (position > e->pos)
00949                                 e->pos = position;
00950                         }
00951                     }
00952                     wtvfile_close(pb);
00953                     st->duration = wtv->index_entries[wtv->nb_index_entries - 1].timestamp;
00954                 }
00955             }
00956         }
00957     }
00958 
00959     avio_seek(s->pb, timeline_pos, SEEK_SET);
00960     return 0;
00961 }
00962 
00963 static int read_packet(AVFormatContext *s, AVPacket *pkt)
00964 {
00965     WtvContext *wtv = s->priv_data;
00966     AVIOContext *pb = wtv->pb;
00967     int stream_index, len, ret;
00968 
00969     stream_index = parse_chunks(s, SEEK_TO_DATA, 0, &len);
00970     if (stream_index < 0)
00971         return stream_index;
00972 
00973     ret = av_get_packet(pb, pkt, len - 32);
00974     if (ret < 0)
00975         return ret;
00976     pkt->stream_index = stream_index;
00977     pkt->pts          = wtv->pts;
00978     avio_skip(pb, WTV_PAD8(len) - len);
00979     return 0;
00980 }
00981 
00982 static int read_seek(AVFormatContext *s, int stream_index,
00983                      int64_t ts, int flags)
00984 {
00985     WtvContext *wtv = s->priv_data;
00986     AVIOContext *pb = wtv->pb;
00987     AVStream *st = s->streams[0];
00988     int64_t ts_relative;
00989     int i;
00990 
00991     if ((flags & AVSEEK_FLAG_FRAME) || (flags & AVSEEK_FLAG_BYTE))
00992         return AVERROR(ENOSYS);
00993 
00994     /* timestamp adjustment is required because wtv->pts values are absolute,
00995      * whereas AVIndexEntry->timestamp values are relative to epoch. */
00996     ts_relative = ts;
00997     if (wtv->epoch != AV_NOPTS_VALUE)
00998         ts_relative -= wtv->epoch;
00999 
01000     i = ff_index_search_timestamp(wtv->index_entries, wtv->nb_index_entries, ts_relative, flags);
01001     if (i < 0) {
01002         if (wtv->last_valid_pts == AV_NOPTS_VALUE || ts < wtv->last_valid_pts) {
01003             if (avio_seek(pb, 0, SEEK_SET) < 0)
01004                 return -1;
01005         } else if (st->duration != AV_NOPTS_VALUE && ts_relative > st->duration && wtv->nb_index_entries) {
01006             if (avio_seek(pb, wtv->index_entries[wtv->nb_index_entries - 1].pos, SEEK_SET) < 0)
01007                 return -1;
01008         }
01009         if (parse_chunks(s, SEEK_TO_PTS, ts, 0) < 0)
01010             return AVERROR(ERANGE);
01011         return 0;
01012     }
01013     if (avio_seek(pb, wtv->index_entries[i].pos, SEEK_SET) < 0)
01014         return -1;
01015     wtv->pts = wtv->index_entries[i].timestamp;
01016     if (wtv->epoch != AV_NOPTS_VALUE)
01017         wtv->pts += wtv->epoch;
01018     wtv->last_valid_pts = wtv->pts;
01019     return 0;
01020 }
01021 
01022 static int read_close(AVFormatContext *s)
01023 {
01024     WtvContext *wtv = s->priv_data;
01025     wtvfile_close(wtv->pb);
01026     return 0;
01027 }
01028 
01029 AVInputFormat ff_wtv_demuxer = {
01030     .name           = "wtv",
01031     .long_name      = NULL_IF_CONFIG_SMALL("Windows Television (WTV)"),
01032     .priv_data_size = sizeof(WtvContext),
01033     .read_probe     = read_probe,
01034     .read_header    = read_header,
01035     .read_packet    = read_packet,
01036     .read_seek      = read_seek,
01037     .read_close     = read_close,
01038     .flags          = AVFMT_SHOW_IDS,
01039 };