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.h"
00030 #include "avformat.h"
00031 #include "internal.h"
00032 #include "wtv.h"
00033 #include "mpegts.h"
00034 
00035 /* Macros for formating GUIDs */
00036 #define PRI_PRETTY_GUID \
00037     "%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x"
00038 #define ARG_PRETTY_GUID(g) \
00039     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]
00040 #define LEN_PRETTY_GUID 34
00041 
00042 /*
00043  *
00044  * File system routines
00045  *
00046  */
00047 
00048 typedef struct {
00049     AVIOContext *pb_filesystem;  
00051     int sector_bits;     
00052     uint32_t *sectors;   
00053     int nb_sectors;      
00055     int error;
00056     int64_t position;
00057     int64_t length;
00058 } WtvFile;
00059 
00063 static int wtvfile_read_packet(void *opaque, uint8_t *buf, int buf_size)
00064 {
00065     WtvFile *wf = opaque;
00066     AVIOContext *pb = wf->pb_filesystem;
00067     int nread = 0;
00068 
00069     if (wf->error || pb->error)
00070         return -1;
00071     if (wf->position >= wf->length || url_feof(pb))
00072         return 0;
00073 
00074     buf_size = FFMIN(buf_size, wf->length - wf->position);
00075     while(nread < buf_size) {
00076         int n;
00077         int remaining_in_sector = (1 << wf->sector_bits) - (wf->position & ((1 << wf->sector_bits) - 1));
00078         int read_request        = FFMIN(buf_size - nread, remaining_in_sector);
00079 
00080         n = avio_read(pb, buf, read_request);
00081         if (n <= 0)
00082             break;
00083         nread += n;
00084         buf += n;
00085         wf->position += n;
00086         if (n == remaining_in_sector) {
00087             int i = wf->position >> wf->sector_bits;
00088             if (i >= wf->nb_sectors ||
00089                 (wf->sectors[i] != wf->sectors[i - 1] + (1 << (wf->sector_bits - WTV_SECTOR_BITS)) &&
00090                 avio_seek(pb, (int64_t)wf->sectors[i] << WTV_SECTOR_BITS, SEEK_SET) < 0)) {
00091                 wf->error = 1;
00092                 break;
00093             }
00094         }
00095     }
00096     return nread;
00097 }
00098 
00102 static int64_t wtvfile_seek(void *opaque, int64_t offset, int whence)
00103 {
00104     WtvFile *wf = opaque;
00105     AVIOContext *pb = wf->pb_filesystem;
00106 
00107     if (whence == AVSEEK_SIZE)
00108         return wf->length;
00109     else if (whence == SEEK_CUR)
00110         offset = wf->position + offset;
00111     else if (whence == SEEK_END)
00112         offset = wf->length;
00113 
00114     wf->error = offset < 0 || offset >= wf->length ||
00115                 avio_seek(pb, ((int64_t)wf->sectors[offset >> wf->sector_bits] << WTV_SECTOR_BITS)
00116                               + (offset & ((1 << wf->sector_bits) - 1)), SEEK_SET) < 0;
00117     wf->position = offset;
00118     return offset;
00119 }
00120 
00128 static int read_ints(AVIOContext *pb, uint32_t *data, int count)
00129 {
00130     int i, total = 0;
00131     for (i = 0; i < count; i++) {
00132         if ((data[total] = avio_rl32(pb)))
00133            total++;
00134     }
00135     return total;
00136 }
00137 
00145 static AVIOContext * wtvfile_open_sector(int first_sector, uint64_t length, int depth, AVFormatContext *s)
00146 {
00147     AVIOContext *pb;
00148     WtvFile *wf;
00149     uint8_t *buffer;
00150 
00151     if (avio_seek(s->pb, first_sector << WTV_SECTOR_BITS, SEEK_SET) < 0)
00152         return NULL;
00153 
00154     wf = av_mallocz(sizeof(WtvFile));
00155     if (!wf)
00156         return NULL;
00157 
00158     if (depth == 0) {
00159         wf->sectors = av_malloc(sizeof(uint32_t));
00160         if (!wf->sectors) {
00161             av_free(wf);
00162             return NULL;
00163         }
00164         wf->sectors[0]  = first_sector;
00165         wf->nb_sectors  = 1;
00166     } else if (depth == 1) {
00167         wf->sectors = av_malloc(WTV_SECTOR_SIZE);
00168         if (!wf->sectors) {
00169             av_free(wf);
00170             return NULL;
00171         }
00172         wf->nb_sectors  = read_ints(s->pb, wf->sectors, WTV_SECTOR_SIZE / 4);
00173     } else if (depth == 2) {
00174         uint32_t sectors1[WTV_SECTOR_SIZE / 4];
00175         int nb_sectors1 = read_ints(s->pb, sectors1, WTV_SECTOR_SIZE / 4);
00176         int i;
00177 
00178         wf->sectors = av_malloc(nb_sectors1 << WTV_SECTOR_BITS);
00179         if (!wf->sectors) {
00180             av_free(wf);
00181             return NULL;
00182         }
00183         wf->nb_sectors = 0;
00184         for (i = 0; i < nb_sectors1; i++) {
00185             if (avio_seek(s->pb, (int64_t)sectors1[i] << WTV_SECTOR_BITS, SEEK_SET) < 0)
00186                 break;
00187             wf->nb_sectors += read_ints(s->pb, wf->sectors + i * WTV_SECTOR_SIZE / 4, WTV_SECTOR_SIZE / 4);
00188         }
00189     } else {
00190         av_log(s, AV_LOG_ERROR, "unsupported file allocation table depth (0x%x)\n", depth);
00191         av_free(wf);
00192         return NULL;
00193     }
00194     wf->sector_bits = length & (1ULL<<63) ? WTV_SECTOR_BITS : WTV_BIGSECTOR_BITS;
00195 
00196     if (!wf->nb_sectors) {
00197         av_free(wf->sectors);
00198         av_free(wf);
00199         return NULL;
00200     }
00201 
00202     /* check length */
00203     length &= 0xFFFFFFFFFFFF;
00204     if (length > ((int64_t)wf->nb_sectors << wf->sector_bits)) {
00205         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);
00206         length = (int64_t)wf->nb_sectors <<  wf->sector_bits;
00207     }
00208     wf->length = length;
00209 
00210     /* seek to initial sector */
00211     wf->position = 0;
00212     if (avio_seek(s->pb, (int64_t)wf->sectors[0] << WTV_SECTOR_BITS, SEEK_SET) < 0) {
00213         av_free(wf->sectors);
00214         av_free(wf);
00215         return NULL;
00216     }
00217 
00218     wf->pb_filesystem = s->pb;
00219     buffer = av_malloc(1 << wf->sector_bits);
00220     if (!buffer) {
00221         av_free(wf->sectors);
00222         av_free(wf);
00223         return NULL;
00224     }
00225 
00226     pb = avio_alloc_context(buffer, 1 << wf->sector_bits, 0, wf,
00227                            wtvfile_read_packet, NULL, wtvfile_seek);
00228     if (!pb) {
00229         av_free(buffer);
00230         av_free(wf->sectors);
00231         av_free(wf);
00232     }
00233     return pb;
00234 }
00235 
00244 static AVIOContext * wtvfile_open2(AVFormatContext *s, const uint8_t *buf, int buf_size, const uint8_t *filename, int filename_size)
00245 {
00246     const uint8_t *buf_end = buf + buf_size;
00247 
00248     while(buf + 48 <= buf_end) {
00249         int dir_length, name_size, first_sector, depth;
00250         uint64_t file_length;
00251         const uint8_t *name;
00252         if (ff_guidcmp(buf, ff_dir_entry_guid)) {
00253             av_log(s, AV_LOG_ERROR, "unknown guid "FF_PRI_GUID", expected dir_entry_guid; "
00254                    "remaining directory entries ignored\n", FF_ARG_GUID(buf));
00255             break;
00256         }
00257         dir_length  = AV_RL16(buf + 16);
00258         file_length = AV_RL64(buf + 24);
00259         name_size   = 2 * AV_RL32(buf + 32);
00260         if (buf + 48 + (int64_t)name_size > buf_end || name_size<0) {
00261             av_log(s, AV_LOG_ERROR, "filename exceeds buffer size; remaining directory entries ignored\n");
00262             break;
00263         }
00264         first_sector = AV_RL32(buf + 40 + name_size);
00265         depth        = AV_RL32(buf + 44 + name_size);
00266 
00267         /* compare file name; test optional null terminator */
00268         name = buf + 40;
00269         if (name_size >= filename_size &&
00270             !memcmp(name, filename, filename_size) &&
00271             (name_size < filename_size + 2 || !AV_RN16(name + filename_size)))
00272             return wtvfile_open_sector(first_sector, file_length, depth, s);
00273 
00274         buf += dir_length;
00275     }
00276     return 0;
00277 }
00278 
00279 #define wtvfile_open(s, buf, buf_size, filename) \
00280     wtvfile_open2(s, buf, buf_size, filename, sizeof(filename))
00281 
00285 static void wtvfile_close(AVIOContext *pb)
00286 {
00287     WtvFile *wf = pb->opaque;
00288     av_free(wf->sectors);
00289     av_freep(&pb->opaque);
00290     av_freep(&pb->buffer);
00291     av_free(pb);
00292 }
00293 
00294 /*
00295  *
00296  * Main demuxer
00297  *
00298  */
00299 
00300 typedef struct {
00301     int seen_data;
00302 } WtvStream;
00303 
00304 typedef struct {
00305     AVIOContext *pb;       
00306     int64_t epoch;
00307     int64_t pts;             
00308     int64_t last_valid_pts;  
00310     /* maintain private seek index, as the AVIndexEntry->pos is relative to the
00311        start of the 'timeline' file, not the file system (AVFormatContext->pb) */
00312     AVIndexEntry *index_entries;
00313     int nb_index_entries;
00314     unsigned int index_entries_allocated_size;
00315 } WtvContext;
00316 
00317 /* WTV GUIDs */
00318 static const ff_asf_guid EVENTID_SubtitleSpanningEvent =
00319     {0x48,0xC0,0xCE,0x5D,0xB9,0xD0,0x63,0x41,0x87,0x2C,0x4F,0x32,0x22,0x3B,0xE8,0x8A};
00320 static const ff_asf_guid EVENTID_LanguageSpanningEvent =
00321     {0x6D,0x66,0x92,0xE2,0x02,0x9C,0x8D,0x44,0xAA,0x8D,0x78,0x1A,0x93,0xFD,0xC3,0x95};
00322 static const ff_asf_guid EVENTID_AudioDescriptorSpanningEvent =
00323     {0x1C,0xD4,0x7B,0x10,0xDA,0xA6,0x91,0x46,0x83,0x69,0x11,0xB2,0xCD,0xAA,0x28,0x8E};
00324 static const ff_asf_guid EVENTID_CtxADescriptorSpanningEvent =
00325     {0xE6,0xA2,0xB4,0x3A,0x47,0x42,0x34,0x4B,0x89,0x6C,0x30,0xAF,0xA5,0xD2,0x1C,0x24};
00326 static const ff_asf_guid EVENTID_CSDescriptorSpanningEvent =
00327     {0xD9,0x79,0xE7,0xEf,0xF0,0x97,0x86,0x47,0x80,0x0D,0x95,0xCF,0x50,0x5D,0xDC,0x66};
00328 static const ff_asf_guid EVENTID_DVBScramblingControlSpanningEvent =
00329     {0xC4,0xE1,0xD4,0x4B,0xA1,0x90,0x09,0x41,0x82,0x36,0x27,0xF0,0x0E,0x7D,0xCC,0x5B};
00330 static const ff_asf_guid EVENTID_StreamIDSpanningEvent =
00331     {0x68,0xAB,0xF1,0xCA,0x53,0xE1,0x41,0x4D,0xA6,0xB3,0xA7,0xC9,0x98,0xDB,0x75,0xEE};
00332 static const ff_asf_guid EVENTID_TeletextSpanningEvent =
00333     {0x50,0xD9,0x99,0x95,0x33,0x5F,0x17,0x46,0xAF,0x7C,0x1E,0x54,0xB5,0x10,0xDA,0xA3};
00334 static const ff_asf_guid EVENTID_AudioTypeSpanningEvent =
00335     {0xBE,0xBF,0x1C,0x50,0x49,0xB8,0xCE,0x42,0x9B,0xE9,0x3D,0xB8,0x69,0xFB,0x82,0xB3};
00336 
00337 /* Windows media GUIDs */
00338 
00339 /* Media types */
00340 static const ff_asf_guid mediasubtype_mpeg1payload =
00341     {0x81,0xEB,0x36,0xE4,0x4F,0x52,0xCE,0x11,0x9F,0x53,0x00,0x20,0xAF,0x0B,0xA7,0x70};
00342 static const ff_asf_guid mediatype_mpeg2_sections =
00343     {0x6C,0x17,0x5F,0x45,0x06,0x4B,0xCE,0x47,0x9A,0xEF,0x8C,0xAE,0xF7,0x3D,0xF7,0xB5};
00344 static const ff_asf_guid mediatype_mpeg2_pes =
00345     {0x20,0x80,0x6D,0xE0,0x46,0xDB,0xCF,0x11,0xB4,0xD1,0x00,0x80,0x5F,0x6C,0xBB,0xEA};
00346 static const ff_asf_guid mediatype_mstvcaption =
00347     {0x89,0x8A,0x8B,0xB8,0x49,0xB0,0x80,0x4C,0xAD,0xCF,0x58,0x98,0x98,0x5E,0x22,0xC1};
00348 
00349 /* Media subtypes */
00350 static const ff_asf_guid mediasubtype_dvb_subtitle =
00351     {0xC3,0xCB,0xFF,0x34,0xB3,0xD5,0x71,0x41,0x90,0x02,0xD4,0xC6,0x03,0x01,0x69,0x7F};
00352 static const ff_asf_guid mediasubtype_teletext =
00353     {0xE3,0x76,0x2A,0xF7,0x0A,0xEB,0xD0,0x11,0xAC,0xE4,0x00,0x00,0xC0,0xCC,0x16,0xBA};
00354 static const ff_asf_guid mediasubtype_dtvccdata =
00355     {0xAA,0xDD,0x2A,0xF5,0xF0,0x36,0xF5,0x43,0x95,0xEA,0x6D,0x86,0x64,0x84,0x26,0x2A};
00356 static const ff_asf_guid mediasubtype_mpeg2_sections =
00357     {0x79,0x85,0x9F,0x4A,0xF8,0x6B,0x92,0x43,0x8A,0x6D,0xD2,0xDD,0x09,0xFA,0x78,0x61};
00358 
00359 /* Formats */
00360 static const ff_asf_guid format_videoinfo2 =
00361     {0xA0,0x76,0x2A,0xF7,0x0A,0xEB,0xD0,0x11,0xAC,0xE4,0x00,0x00,0xC0,0xCC,0x16,0xBA};
00362 
00363 static int read_probe(AVProbeData *p)
00364 {
00365     return ff_guidcmp(p->buf, ff_wtv_guid) ? 0 : AVPROBE_SCORE_MAX;
00366 }
00367 
00372 static int filetime_to_iso8601(char *buf, int buf_size, int64_t value)
00373 {
00374     time_t t = (value / 10000000LL) - 11644473600LL;
00375     struct tm *tm = gmtime(&t);
00376     if (!tm)
00377         return -1;
00378     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
00379     return 0;
00380 }
00381 
00386 static int crazytime_to_iso8601(char *buf, int buf_size, int64_t value)
00387 {
00388     time_t t = (value / 10000000LL) - 719162LL*86400LL;
00389     struct tm *tm = gmtime(&t);
00390     if (!tm)
00391         return -1;
00392     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
00393     return 0;
00394 }
00395 
00400 static int oledate_to_iso8601(char *buf, int buf_size, int64_t value)
00401 {
00402     time_t t = (av_int2double(value) - 25569.0) * 86400;
00403     struct tm *result= gmtime(&t);
00404     if (!result)
00405         return -1;
00406     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", result);
00407     return 0;
00408 }
00409 
00410 static void get_attachment(AVFormatContext *s, AVIOContext *pb, int length)
00411 {
00412     char mime[1024];
00413     char description[1024];
00414     unsigned int filesize;
00415     AVStream *st;
00416     int64_t pos = avio_tell(pb);
00417 
00418     avio_get_str16le(pb, INT_MAX, mime, sizeof(mime));
00419     if (strcmp(mime, "image/jpeg"))
00420         goto done;
00421 
00422     avio_r8(pb);
00423     avio_get_str16le(pb, INT_MAX, description, sizeof(description));
00424     filesize = avio_rl32(pb);
00425     if (!filesize)
00426         goto done;
00427 
00428     st = avformat_new_stream(s, NULL);
00429     if (!st)
00430         goto done;
00431     av_dict_set(&st->metadata, "title", description, 0);
00432     st->codec->codec_id   = AV_CODEC_ID_MJPEG;
00433     st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
00434     st->codec->extradata  = av_mallocz(filesize);
00435     if (!st->codec->extradata)
00436         goto done;
00437     st->codec->extradata_size = filesize;
00438     avio_read(pb, st->codec->extradata, filesize);
00439 done:
00440     avio_seek(pb, pos + length, SEEK_SET);
00441 }
00442 
00443 static void get_tag(AVFormatContext *s, AVIOContext *pb, const char *key, int type, int length)
00444 {
00445     int buf_size = FFMAX(2*length, LEN_PRETTY_GUID) + 1;
00446     char *buf = av_malloc(buf_size);
00447     if (!buf)
00448         return;
00449 
00450     if (type == 0 && length == 4) {
00451         snprintf(buf, buf_size, "%"PRIi32, avio_rl32(pb));
00452     } else if (type == 1) {
00453         avio_get_str16le(pb, length, buf, buf_size);
00454         if (!strlen(buf)) {
00455            av_free(buf);
00456            return;
00457         }
00458     } else if (type == 3 && length == 4) {
00459         strcpy(buf, avio_rl32(pb) ? "true" : "false");
00460     } else if (type == 4 && length == 8) {
00461         int64_t num = avio_rl64(pb);
00462         if (!strcmp(key, "WM/EncodingTime") ||
00463             !strcmp(key, "WM/MediaOriginalBroadcastDateTime")) {
00464             if (filetime_to_iso8601(buf, buf_size, num) < 0) {
00465                 av_free(buf);
00466                 return;
00467             }
00468         } else if (!strcmp(key, "WM/WMRVEncodeTime") ||
00469                    !strcmp(key, "WM/WMRVEndTime")) {
00470             if (crazytime_to_iso8601(buf, buf_size, num) < 0) {
00471                 av_free(buf);
00472                 return;
00473             }
00474         } else if (!strcmp(key, "WM/WMRVExpirationDate")) {
00475             if (oledate_to_iso8601(buf, buf_size, num) < 0 ) {
00476                 av_free(buf);
00477                 return;
00478             }
00479         } else if (!strcmp(key, "WM/WMRVBitrate"))
00480             snprintf(buf, buf_size, "%f", av_int2double(num));
00481         else
00482             snprintf(buf, buf_size, "%"PRIi64, num);
00483     } else if (type == 5 && length == 2) {
00484         snprintf(buf, buf_size, "%"PRIi16, avio_rl16(pb));
00485     } else if (type == 6 && length == 16) {
00486         ff_asf_guid guid;
00487         avio_read(pb, guid, 16);
00488         snprintf(buf, buf_size, PRI_PRETTY_GUID, ARG_PRETTY_GUID(guid));
00489     } else if (type == 2 && !strcmp(key, "WM/Picture")) {
00490         get_attachment(s, pb, length);
00491         av_freep(&buf);
00492         return;
00493     } else {
00494         av_freep(&buf);
00495         av_log(s, AV_LOG_WARNING, "unsupported metadata entry; key:%s, type:%d, length:0x%x\n", key, type, length);
00496         avio_skip(pb, length);
00497         return;
00498     }
00499 
00500     av_dict_set(&s->metadata, key, buf, 0);
00501     av_freep(&buf);
00502 }
00503 
00507 static void parse_legacy_attrib(AVFormatContext *s, AVIOContext *pb)
00508 {
00509     ff_asf_guid guid;
00510     int length, type;
00511     while(!url_feof(pb)) {
00512         char key[1024];
00513         ff_get_guid(pb, &guid);
00514         type   = avio_rl32(pb);
00515         length = avio_rl32(pb);
00516         if (!length)
00517             break;
00518         if (ff_guidcmp(&guid, ff_metadata_guid)) {
00519             av_log(s, AV_LOG_WARNING, "unknown guid "FF_PRI_GUID", expected metadata_guid; "
00520                    "remaining metadata entries ignored\n", FF_ARG_GUID(guid));
00521             break;
00522         }
00523         avio_get_str16le(pb, INT_MAX, key, sizeof(key));
00524         get_tag(s, pb, key, type, length);
00525     }
00526 
00527     ff_metadata_conv(&s->metadata, NULL, ff_asf_metadata_conv);
00528 }
00529 
00534 static int parse_videoinfoheader2(AVFormatContext *s, AVStream *st)
00535 {
00536     WtvContext *wtv = s->priv_data;
00537     AVIOContext *pb = wtv->pb;
00538 
00539     avio_skip(pb, 72);  // picture aspect ratio is unreliable
00540     ff_get_bmp_header(pb, st, NULL);
00541 
00542     return 72 + 40;
00543 }
00544 
00548 static void parse_mpeg1waveformatex(AVStream *st)
00549 {
00550     /* fwHeadLayer */
00551     switch (AV_RL16(st->codec->extradata)) {
00552     case 0x0001 : st->codec->codec_id = AV_CODEC_ID_MP1; break;
00553     case 0x0002 : st->codec->codec_id = AV_CODEC_ID_MP2; break;
00554     case 0x0004 : st->codec->codec_id = AV_CODEC_ID_MP3; break;
00555     }
00556 
00557     st->codec->bit_rate = AV_RL32(st->codec->extradata + 2); /* dwHeadBitrate */
00558 
00559     /* dwHeadMode */
00560     switch (AV_RL16(st->codec->extradata + 6)) {
00561     case 1 : case 2 : case 4 : st->codec->channels = 2; break;
00562     case 8 :                   st->codec->channels = 1; break;
00563     }
00564 }
00565 
00571 static AVStream * new_stream(AVFormatContext *s, AVStream *st, int sid, int codec_type)
00572 {
00573     if (st) {
00574         if (st->codec->extradata) {
00575             av_freep(&st->codec->extradata);
00576             st->codec->extradata_size = 0;
00577         }
00578     } else {
00579         WtvStream *wst = av_mallocz(sizeof(WtvStream));
00580         if (!wst)
00581             return NULL;
00582         st = avformat_new_stream(s, NULL);
00583         if (!st)
00584             return NULL;
00585         st->id = sid;
00586         st->priv_data = wst;
00587     }
00588     st->codec->codec_type = codec_type;
00589     st->need_parsing      = AVSTREAM_PARSE_FULL;
00590     avpriv_set_pts_info(st, 64, 1, 10000000);
00591     return st;
00592 }
00593 
00603 static AVStream * parse_media_type(AVFormatContext *s, AVStream *st, int sid,
00604                                    ff_asf_guid mediatype, ff_asf_guid subtype,
00605                                    ff_asf_guid formattype, int size)
00606 {
00607     WtvContext *wtv = s->priv_data;
00608     AVIOContext *pb = wtv->pb;
00609     if (!ff_guidcmp(subtype, ff_mediasubtype_cpfilters_processed) &&
00610         !ff_guidcmp(formattype, ff_format_cpfilters_processed)) {
00611         ff_asf_guid actual_subtype;
00612         ff_asf_guid actual_formattype;
00613 
00614         if (size < 32) {
00615             av_log(s, AV_LOG_WARNING, "format buffer size underflow\n");
00616             avio_skip(pb, size);
00617             return NULL;
00618         }
00619 
00620         avio_skip(pb, size - 32);
00621         ff_get_guid(pb, &actual_subtype);
00622         ff_get_guid(pb, &actual_formattype);
00623         avio_seek(pb, -size, SEEK_CUR);
00624 
00625         st = parse_media_type(s, st, sid, mediatype, actual_subtype, actual_formattype, size - 32);
00626         avio_skip(pb, 32);
00627         return st;
00628     } else if (!ff_guidcmp(mediatype, ff_mediatype_audio)) {
00629         st = new_stream(s, st, sid, AVMEDIA_TYPE_AUDIO);
00630         if (!st)
00631             return NULL;
00632         if (!ff_guidcmp(formattype, ff_format_waveformatex)) {
00633             int ret = ff_get_wav_header(pb, st->codec, size);
00634             if (ret < 0)
00635                 return NULL;
00636         } else {
00637             if (ff_guidcmp(formattype, ff_format_none))
00638                 av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
00639             avio_skip(pb, size);
00640         }
00641 
00642         if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {
00643             st->codec->codec_id = ff_wav_codec_get_id(AV_RL32(subtype), st->codec->bits_per_coded_sample);
00644         } else if (!ff_guidcmp(subtype, mediasubtype_mpeg1payload)) {
00645             if (st->codec->extradata && st->codec->extradata_size >= 22)
00646                 parse_mpeg1waveformatex(st);
00647             else
00648                 av_log(s, AV_LOG_WARNING, "MPEG1WAVEFORMATEX underflow\n");
00649         } else {
00650             st->codec->codec_id = ff_codec_guid_get_id(ff_codec_wav_guids, subtype);
00651             if (st->codec->codec_id == AV_CODEC_ID_NONE)
00652                 av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID"\n", FF_ARG_GUID(subtype));
00653         }
00654         return st;
00655     } else if (!ff_guidcmp(mediatype, ff_mediatype_video)) {
00656         st = new_stream(s, st, sid, AVMEDIA_TYPE_VIDEO);
00657         if (!st)
00658             return NULL;
00659         if (!ff_guidcmp(formattype, format_videoinfo2)) {
00660             int consumed = parse_videoinfoheader2(s, st);
00661             avio_skip(pb, FFMAX(size - consumed, 0));
00662         } else if (!ff_guidcmp(formattype, ff_format_mpeg2_video)) {
00663             int consumed = parse_videoinfoheader2(s, st);
00664             avio_skip(pb, FFMAX(size - consumed, 0));
00665         } else {
00666             if (ff_guidcmp(formattype, ff_format_none))
00667                 av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
00668             avio_skip(pb, size);
00669         }
00670 
00671         if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {
00672             st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, AV_RL32(subtype));
00673         } else {
00674             st->codec->codec_id = ff_codec_guid_get_id(ff_video_guids, subtype);
00675         }
00676         if (st->codec->codec_id == AV_CODEC_ID_NONE)
00677             av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID"\n", FF_ARG_GUID(subtype));
00678         return st;
00679     } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_pes) &&
00680                !ff_guidcmp(subtype, mediasubtype_dvb_subtitle)) {
00681         st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);
00682         if (!st)
00683             return NULL;
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         st->codec->codec_id = AV_CODEC_ID_DVB_SUBTITLE;
00688         return st;
00689     } else if (!ff_guidcmp(mediatype, mediatype_mstvcaption) &&
00690                (!ff_guidcmp(subtype, mediasubtype_teletext) || !ff_guidcmp(subtype, mediasubtype_dtvccdata))) {
00691         st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);
00692         if (!st)
00693             return NULL;
00694         if (ff_guidcmp(formattype, ff_format_none))
00695             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
00696         avio_skip(pb, size);
00697         st->codec->codec_id = !ff_guidcmp(subtype, mediasubtype_teletext) ? AV_CODEC_ID_DVB_TELETEXT : AV_CODEC_ID_EIA_608;
00698         return st;
00699     } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_sections) &&
00700                !ff_guidcmp(subtype, mediasubtype_mpeg2_sections)) {
00701         if (ff_guidcmp(formattype, ff_format_none))
00702             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));
00703         avio_skip(pb, size);
00704         return NULL;
00705     }
00706 
00707     av_log(s, AV_LOG_WARNING, "unknown media type, mediatype:"FF_PRI_GUID
00708                               ", subtype:"FF_PRI_GUID", formattype:"FF_PRI_GUID"\n",
00709                               FF_ARG_GUID(mediatype), FF_ARG_GUID(subtype), FF_ARG_GUID(formattype));
00710     avio_skip(pb, size);
00711     return NULL;
00712 }
00713 
00714 enum {
00715     SEEK_TO_DATA = 0,
00716     SEEK_TO_PTS,
00717 };
00718 
00726 static int parse_chunks(AVFormatContext *s, int mode, int64_t seekts, int *len_ptr)
00727 {
00728     WtvContext *wtv = s->priv_data;
00729     AVIOContext *pb = wtv->pb;
00730     while (!url_feof(pb)) {
00731         ff_asf_guid g;
00732         int len, sid, consumed;
00733 
00734         ff_get_guid(pb, &g);
00735         len = avio_rl32(pb);
00736         if (len < 32)
00737             break;
00738         sid = avio_rl32(pb) & 0x7FFF;
00739         avio_skip(pb, 8);
00740         consumed = 32;
00741 
00742         if (!ff_guidcmp(g, ff_stream_guid)) {
00743             if (ff_find_stream_index(s, sid) < 0) {
00744                 ff_asf_guid mediatype, subtype, formattype;
00745                 int size;
00746                 avio_skip(pb, 28);
00747                 ff_get_guid(pb, &mediatype);
00748                 ff_get_guid(pb, &subtype);
00749                 avio_skip(pb, 12);
00750                 ff_get_guid(pb, &formattype);
00751                 size = avio_rl32(pb);
00752                 parse_media_type(s, 0, sid, mediatype, subtype, formattype, size);
00753                 consumed += 92 + size;
00754             }
00755         } else if (!ff_guidcmp(g, ff_stream2_guid)) {
00756             int stream_index = ff_find_stream_index(s, sid);
00757             if (stream_index >= 0 && !((WtvStream*)s->streams[stream_index]->priv_data)->seen_data) {
00758                 ff_asf_guid mediatype, subtype, formattype;
00759                 int size;
00760                 avio_skip(pb, 12);
00761                 ff_get_guid(pb, &mediatype);
00762                 ff_get_guid(pb, &subtype);
00763                 avio_skip(pb, 12);
00764                 ff_get_guid(pb, &formattype);
00765                 size = avio_rl32(pb);
00766                 parse_media_type(s, s->streams[stream_index], sid, mediatype, subtype, formattype, size);
00767                 consumed += 76 + size;
00768             }
00769         } else if (!ff_guidcmp(g, EVENTID_AudioDescriptorSpanningEvent) ||
00770                    !ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
00771                    !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent) ||
00772                    !ff_guidcmp(g, EVENTID_StreamIDSpanningEvent) ||
00773                    !ff_guidcmp(g, EVENTID_SubtitleSpanningEvent) ||
00774                    !ff_guidcmp(g, EVENTID_TeletextSpanningEvent)) {
00775             int stream_index = ff_find_stream_index(s, sid);
00776             if (stream_index >= 0) {
00777                 AVStream *st = s->streams[stream_index];
00778                 uint8_t buf[258];
00779                 const uint8_t *pbuf = buf;
00780                 int buf_size;
00781 
00782                 avio_skip(pb, 8);
00783                 consumed += 8;
00784                 if (!ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
00785                     !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent)) {
00786                     avio_skip(pb, 6);
00787                     consumed += 6;
00788                 }
00789 
00790                 buf_size = FFMIN(len - consumed, sizeof(buf));
00791                 avio_read(pb, buf, buf_size);
00792                 consumed += buf_size;
00793                 ff_parse_mpeg2_descriptor(s, st, 0, &pbuf, buf + buf_size, NULL, 0, 0, NULL);
00794             }
00795         } else if (!ff_guidcmp(g, EVENTID_AudioTypeSpanningEvent)) {
00796             int stream_index = ff_find_stream_index(s, sid);
00797             if (stream_index >= 0) {
00798                 AVStream *st = s->streams[stream_index];
00799                 int audio_type;
00800                 avio_skip(pb, 8);
00801                 audio_type = avio_r8(pb);
00802                 if (audio_type == 2)
00803                     st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
00804                 else if (audio_type == 3)
00805                     st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
00806                 consumed += 9;
00807             }
00808         } else if (!ff_guidcmp(g, EVENTID_DVBScramblingControlSpanningEvent)) {
00809             int stream_index = ff_find_stream_index(s, sid);
00810             if (stream_index >= 0) {
00811                 avio_skip(pb, 12);
00812                 if (avio_rl32(pb))
00813                     av_log(s, AV_LOG_WARNING, "DVB scrambled stream detected (st:%d), decoding will likely fail\n", stream_index);
00814                 consumed += 16;
00815             }
00816         } else if (!ff_guidcmp(g, EVENTID_LanguageSpanningEvent)) {
00817             int stream_index = ff_find_stream_index(s, sid);
00818             if (stream_index >= 0) {
00819                 AVStream *st = s->streams[stream_index];
00820                 uint8_t language[4];
00821                 avio_skip(pb, 12);
00822                 avio_read(pb, language, 3);
00823                 if (language[0]) {
00824                     language[3] = 0;
00825                     av_dict_set(&st->metadata, "language", language, 0);
00826                     if (!strcmp(language, "nar") || !strcmp(language, "NAR"))
00827                         st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
00828                 }
00829                 consumed += 15;
00830             }
00831         } else if (!ff_guidcmp(g, ff_timestamp_guid)) {
00832             int stream_index = ff_find_stream_index(s, sid);
00833             if (stream_index >= 0) {
00834                 avio_skip(pb, 8);
00835                 wtv->pts = avio_rl64(pb);
00836                 consumed += 16;
00837                 if (wtv->pts == -1)
00838                     wtv->pts = AV_NOPTS_VALUE;
00839                 else {
00840                     wtv->last_valid_pts = wtv->pts;
00841                     if (wtv->epoch == AV_NOPTS_VALUE || wtv->pts < wtv->epoch)
00842                         wtv->epoch = wtv->pts;
00843                 if (mode == SEEK_TO_PTS && wtv->pts >= seekts) {
00844                     avio_skip(pb, WTV_PAD8(len) - consumed);
00845                     return 0;
00846                 }
00847                 }
00848             }
00849         } else if (!ff_guidcmp(g, ff_data_guid)) {
00850             int stream_index = ff_find_stream_index(s, sid);
00851             if (mode == SEEK_TO_DATA && stream_index >= 0 && len > 32 && s->streams[stream_index]->priv_data) {
00852                 WtvStream *wst = s->streams[stream_index]->priv_data;
00853                 wst->seen_data = 1;
00854                 if (len_ptr) {
00855                     *len_ptr = len;
00856                 }
00857                 return stream_index;
00858             }
00859         } else if (
00860             !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}) ||
00861             !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}) ||
00862             !ff_guidcmp(g, /* DSATTRIB_TRANSPORT_PROPERTIES */ ff_DSATTRIB_TRANSPORT_PROPERTIES) ||
00863             !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}) ||
00864             !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}) ||
00865             !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}) ||
00866             !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}) ||
00867             !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}) ||
00868             !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}) ||
00869             !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}) ||
00870             !ff_guidcmp(g, (const ff_asf_guid){0x1E,0xBE,0xC3,0xC5,0x43,0x92,0xDC,0x11,0x85,0xE5,0x00,0x12,0x3F,0x6F,0x73,0xB9}) ||
00871             !ff_guidcmp(g, (const ff_asf_guid){0x3B,0x86,0xA2,0xB1,0xEB,0x1E,0xC3,0x44,0x8C,0x88,0x1C,0xA3,0xFF,0xE3,0xE7,0x6A}) ||
00872             !ff_guidcmp(g, (const ff_asf_guid){0x4E,0x7F,0x4C,0x5B,0xC4,0xD0,0x38,0x4B,0xA8,0x3E,0x21,0x7F,0x7B,0xBF,0x52,0xE7}) ||
00873             !ff_guidcmp(g, (const ff_asf_guid){0x63,0x36,0xEB,0xFE,0xA1,0x7E,0xD9,0x11,0x83,0x08,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
00874             !ff_guidcmp(g, (const ff_asf_guid){0x70,0xE9,0xF1,0xF8,0x89,0xA4,0x4C,0x4D,0x83,0x73,0xB8,0x12,0xE0,0xD5,0xF8,0x1E}) ||
00875             !ff_guidcmp(g, (const ff_asf_guid){0x96,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
00876             !ff_guidcmp(g, (const ff_asf_guid){0x97,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
00877             !ff_guidcmp(g, (const ff_asf_guid){0xA1,0xC3,0xD2,0xC2,0x7E,0x9A,0xDA,0x11,0x8B,0xF7,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
00878             !ff_guidcmp(g, (const ff_asf_guid){0xF7,0x10,0x02,0xB9,0xEE,0x7C,0xED,0x4E,0xBD,0x7F,0x05,0x40,0x35,0x86,0x18,0xA1})) {
00879             //ignore known guids
00880         } else
00881             av_log(s, AV_LOG_WARNING, "unsupported chunk:"FF_PRI_GUID"\n", FF_ARG_GUID(g));
00882 
00883         avio_skip(pb, WTV_PAD8(len) - consumed);
00884     }
00885     return AVERROR_EOF;
00886 }
00887 
00888 static int read_header(AVFormatContext *s)
00889 {
00890     WtvContext *wtv = s->priv_data;
00891     int root_sector, root_size;
00892     uint8_t root[WTV_SECTOR_SIZE];
00893     AVIOContext *pb;
00894     int64_t timeline_pos;
00895     int ret;
00896 
00897     wtv->epoch          =
00898     wtv->pts            =
00899     wtv->last_valid_pts = AV_NOPTS_VALUE;
00900 
00901     /* read root directory sector */
00902     avio_skip(s->pb, 0x30);
00903     root_size = avio_rl32(s->pb);
00904     if (root_size > sizeof(root)) {
00905         av_log(s, AV_LOG_ERROR, "root directory size exceeds sector size\n");
00906         return AVERROR_INVALIDDATA;
00907     }
00908     avio_skip(s->pb, 4);
00909     root_sector = avio_rl32(s->pb);
00910 
00911     avio_seek(s->pb, root_sector << WTV_SECTOR_BITS, SEEK_SET);
00912     root_size = avio_read(s->pb, root, root_size);
00913     if (root_size < 0)
00914         return AVERROR_INVALIDDATA;
00915 
00916     /* parse chunks up until first data chunk */
00917     wtv->pb = wtvfile_open(s, root, root_size, ff_timeline_le16);
00918     if (!wtv->pb) {
00919         av_log(s, AV_LOG_ERROR, "timeline data missing\n");
00920         return AVERROR_INVALIDDATA;
00921     }
00922 
00923     ret = parse_chunks(s, SEEK_TO_DATA, 0, 0);
00924     if (ret < 0)
00925         return ret;
00926     avio_seek(wtv->pb, -32, SEEK_CUR);
00927 
00928     timeline_pos = avio_tell(s->pb); // save before opening another file
00929 
00930     /* read metadata */
00931     pb = wtvfile_open(s, root, root_size, ff_table_0_entries_legacy_attrib_le16);
00932     if (pb) {
00933         parse_legacy_attrib(s, pb);
00934         wtvfile_close(pb);
00935     }
00936 
00937     /* read seek index */
00938     if (s->nb_streams) {
00939         AVStream *st = s->streams[0];
00940         pb = wtvfile_open(s, root, root_size, ff_table_0_entries_time_le16);
00941         if (pb) {
00942             while(1) {
00943                 uint64_t timestamp = avio_rl64(pb);
00944                 uint64_t frame_nb  = avio_rl64(pb);
00945                 if (url_feof(pb))
00946                     break;
00947                 ff_add_index_entry(&wtv->index_entries, &wtv->nb_index_entries, &wtv->index_entries_allocated_size,
00948                                    0, timestamp, frame_nb, 0, AVINDEX_KEYFRAME);
00949             }
00950             wtvfile_close(pb);
00951 
00952             if (wtv->nb_index_entries) {
00953                 pb = wtvfile_open(s, root, root_size, ff_timeline_table_0_entries_Events_le16);
00954                 if (pb) {
00955                     int i;
00956                     while (1) {
00957                         uint64_t frame_nb = avio_rl64(pb);
00958                         uint64_t position = avio_rl64(pb);
00959                         if (url_feof(pb))
00960                             break;
00961                         for (i = wtv->nb_index_entries - 1; i >= 0; i--) {
00962                             AVIndexEntry *e = wtv->index_entries + i;
00963                             if (frame_nb > e->size)
00964                                 break;
00965                             if (position > e->pos)
00966                                 e->pos = position;
00967                         }
00968                     }
00969                     wtvfile_close(pb);
00970                     st->duration = wtv->index_entries[wtv->nb_index_entries - 1].timestamp;
00971                 }
00972             }
00973         }
00974     }
00975 
00976     avio_seek(s->pb, timeline_pos, SEEK_SET);
00977     return 0;
00978 }
00979 
00980 static int read_packet(AVFormatContext *s, AVPacket *pkt)
00981 {
00982     WtvContext *wtv = s->priv_data;
00983     AVIOContext *pb = wtv->pb;
00984     int stream_index, len, ret;
00985 
00986     stream_index = parse_chunks(s, SEEK_TO_DATA, 0, &len);
00987     if (stream_index < 0)
00988         return stream_index;
00989 
00990     ret = av_get_packet(pb, pkt, len - 32);
00991     if (ret < 0)
00992         return ret;
00993     pkt->stream_index = stream_index;
00994     pkt->pts          = wtv->pts;
00995     avio_skip(pb, WTV_PAD8(len) - len);
00996     return 0;
00997 }
00998 
00999 static int read_seek(AVFormatContext *s, int stream_index,
01000                      int64_t ts, int flags)
01001 {
01002     WtvContext *wtv = s->priv_data;
01003     AVIOContext *pb = wtv->pb;
01004     AVStream *st = s->streams[0];
01005     int64_t ts_relative;
01006     int i;
01007 
01008     if ((flags & AVSEEK_FLAG_FRAME) || (flags & AVSEEK_FLAG_BYTE))
01009         return AVERROR(ENOSYS);
01010 
01011     /* timestamp adjustment is required because wtv->pts values are absolute,
01012      * whereas AVIndexEntry->timestamp values are relative to epoch. */
01013     ts_relative = ts;
01014     if (wtv->epoch != AV_NOPTS_VALUE)
01015         ts_relative -= wtv->epoch;
01016 
01017     i = ff_index_search_timestamp(wtv->index_entries, wtv->nb_index_entries, ts_relative, flags);
01018     if (i < 0) {
01019         if (wtv->last_valid_pts == AV_NOPTS_VALUE || ts < wtv->last_valid_pts) {
01020             if (avio_seek(pb, 0, SEEK_SET) < 0)
01021                 return -1;
01022         } else if (st->duration != AV_NOPTS_VALUE && ts_relative > st->duration && wtv->nb_index_entries) {
01023             if (avio_seek(pb, wtv->index_entries[wtv->nb_index_entries - 1].pos, SEEK_SET) < 0)
01024                 return -1;
01025         }
01026         if (parse_chunks(s, SEEK_TO_PTS, ts, 0) < 0)
01027             return AVERROR(ERANGE);
01028         return 0;
01029     }
01030     if (avio_seek(pb, wtv->index_entries[i].pos, SEEK_SET) < 0)
01031         return -1;
01032     wtv->pts = wtv->index_entries[i].timestamp;
01033     if (wtv->epoch != AV_NOPTS_VALUE)
01034         wtv->pts += wtv->epoch;
01035     wtv->last_valid_pts = wtv->pts;
01036     return 0;
01037 }
01038 
01039 static int read_close(AVFormatContext *s)
01040 {
01041     WtvContext *wtv = s->priv_data;
01042     av_freep(&wtv->index_entries);
01043     wtvfile_close(wtv->pb);
01044     return 0;
01045 }
01046 
01047 AVInputFormat ff_wtv_demuxer = {
01048     .name           = "wtv",
01049     .long_name      = NULL_IF_CONFIG_SMALL("Windows Television (WTV)"),
01050     .priv_data_size = sizeof(WtvContext),
01051     .read_probe     = read_probe,
01052     .read_header    = read_header,
01053     .read_packet    = read_packet,
01054     .read_seek      = read_seek,
01055     .read_close     = read_close,
01056     .flags          = AVFMT_SHOW_IDS,
01057 };