/*
  * Windows Television (WTV) demuxer

  * Copyright (c) 2010-2011 Peter Ross <pross@xvid.org>

  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file
  * Windows Television (WTV) demuxer
  * @author Peter Ross <pross@xvid.org>
  */
 

 #include "libavutil/channel_layout.h"

 #include "libavutil/intreadwrite.h"

 #include "libavutil/intfloat.h"

 #include "avformat.h"

 #include "internal.h"

 #include "wtv.h"

 #include "mpegts.h"

 
 /* Macros for formating GUIDs */

 #define PRI_PRETTY_GUID \
     "%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x"
 #define ARG_PRETTY_GUID(g) \
     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]
 #define LEN_PRETTY_GUID 34
 
 /*
  *
  * File system routines
  *
  */
 

 typedef struct {

     AVIOContext *pb_filesystem;  /**< file system (AVFormatContext->pb) */

     int sector_bits;     /**< sector shift bits; used to convert sector number into pb_filesystem offset */
     uint32_t *sectors;   /**< file allocation table */
     int nb_sectors;      /**< number of sectors */

 
     int error;
     int64_t position;
     int64_t length;
 } WtvFile;
 

 static int64_t seek_by_sector(AVIOContext *pb, int64_t sector, int64_t offset)
 {

     return avio_seek(pb, (sector << WTV_SECTOR_BITS) + offset, SEEK_SET);

 }
 

 /**
  * @return bytes read, 0 on end of file, or <0 on error
  */
 static int wtvfile_read_packet(void *opaque, uint8_t *buf, int buf_size)
 {
     WtvFile *wf = opaque;

     AVIOContext *pb = wf->pb_filesystem;

     int nread = 0;
 

     if (wf->error || pb->error)

         return -1;
     if (wf->position >= wf->length || url_feof(pb))
         return 0;
 
     buf_size = FFMIN(buf_size, wf->length - wf->position);
     while(nread < buf_size) {
         int n;
         int remaining_in_sector = (1 << wf->sector_bits) - (wf->position & ((1 << wf->sector_bits) - 1));
         int read_request        = FFMIN(buf_size - nread, remaining_in_sector);
 

         n = avio_read(pb, buf, read_request);

         if (n <= 0)
             break;
         nread += n;
         buf += n;
         wf->position += n;
         if (n == remaining_in_sector) {
             int i = wf->position >> wf->sector_bits;
             if (i >= wf->nb_sectors ||
                 (wf->sectors[i] != wf->sectors[i - 1] + (1 << (wf->sector_bits - WTV_SECTOR_BITS)) &&

                 seek_by_sector(pb, wf->sectors[i], 0) < 0)) {

                 wf->error = 1;
                 break;
             }
         }
     }
     return nread;
 }
 
 /**
  * @return position (or file length)
  */
 static int64_t wtvfile_seek(void *opaque, int64_t offset, int whence)
 {
     WtvFile *wf = opaque;

     AVIOContext *pb = wf->pb_filesystem;

 
     if (whence == AVSEEK_SIZE)
         return wf->length;
     else if (whence == SEEK_CUR)
         offset = wf->position + offset;
     else if (whence == SEEK_END)
         offset = wf->length;
 
     wf->error = offset < 0 || offset >= wf->length ||

                 seek_by_sector(pb, wf->sectors[offset >> wf->sector_bits],
                                offset & ((1 << wf->sector_bits) - 1)) < 0;

     wf->position = offset;
     return offset;
 }
 
 /**
  * read non-zero integers (le32) from input stream
  * @param pb
  * @param[out] data destination
  * @param     count maximum number of integers to read
  * @return    total number of integers read
  */

 static int read_ints(AVIOContext *pb, uint32_t *data, int count)

 {
     int i, total = 0;
     for (i = 0; i < count; i++) {

         if ((data[total] = avio_rl32(pb)))

            total++;
     }
     return total;
 }
 
 /**
  * Open file
  * @param first_sector  First sector
  * @param length        Length of file (bytes)
  * @param depth         File allocation table depth
  * @return NULL on error
  */

 static AVIOContext * wtvfile_open_sector(int first_sector, uint64_t length, int depth, AVFormatContext *s)

 {

     AVIOContext *pb;

     WtvFile *wf;
     uint8_t *buffer;

     int64_t size;

     if (seek_by_sector(s->pb, first_sector, 0) < 0)

         return NULL;
 
     wf = av_mallocz(sizeof(WtvFile));
     if (!wf)
         return NULL;
 
     if (depth == 0) {
         wf->sectors = av_malloc(sizeof(uint32_t));
         if (!wf->sectors) {
             av_free(wf);
             return NULL;
         }
         wf->sectors[0]  = first_sector;
         wf->nb_sectors  = 1;
     } else if (depth == 1) {
         wf->sectors = av_malloc(WTV_SECTOR_SIZE);
         if (!wf->sectors) {
             av_free(wf);
             return NULL;
         }
         wf->nb_sectors  = read_ints(s->pb, wf->sectors, WTV_SECTOR_SIZE / 4);
     } else if (depth == 2) {
         uint32_t sectors1[WTV_SECTOR_SIZE / 4];
         int nb_sectors1 = read_ints(s->pb, sectors1, WTV_SECTOR_SIZE / 4);
         int i;
 

         wf->sectors = av_malloc_array(nb_sectors1, 1 << WTV_SECTOR_BITS);

         if (!wf->sectors) {
             av_free(wf);
             return NULL;
         }
         wf->nb_sectors = 0;
         for (i = 0; i < nb_sectors1; i++) {

             if (seek_by_sector(s->pb, sectors1[i], 0) < 0)

                 break;
             wf->nb_sectors += read_ints(s->pb, wf->sectors + i * WTV_SECTOR_SIZE / 4, WTV_SECTOR_SIZE / 4);
         }
     } else {
         av_log(s, AV_LOG_ERROR, "unsupported file allocation table depth (0x%x)\n", depth);
         av_free(wf);
         return NULL;
     }

     wf->sector_bits = length & (1ULL<<63) ? WTV_SECTOR_BITS : WTV_BIGSECTOR_BITS;

 
     if (!wf->nb_sectors) {
         av_free(wf->sectors);
         av_free(wf);
         return NULL;
     }
 

     size = avio_size(s->pb);
     if (size >= 0 && (int64_t)wf->sectors[wf->nb_sectors - 1] << WTV_SECTOR_BITS > size)

         av_log(s, AV_LOG_WARNING, "truncated file\n");
 

     /* check length */
     length &= 0xFFFFFFFFFFFF;
     if (length > ((int64_t)wf->nb_sectors << wf->sector_bits)) {
         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);
         length = (int64_t)wf->nb_sectors <<  wf->sector_bits;
     }
     wf->length = length;
 

     /* seek to initial sector */

     wf->position = 0;

     if (seek_by_sector(s->pb, wf->sectors[0], 0) < 0) {

         av_free(wf->sectors);
         av_free(wf);
         return NULL;
     }
 
     wf->pb_filesystem = s->pb;
     buffer = av_malloc(1 << wf->sector_bits);
     if (!buffer) {
         av_free(wf->sectors);
         av_free(wf);
         return NULL;
     }

     pb = avio_alloc_context(buffer, 1 << wf->sector_bits, 0, wf,

                            wtvfile_read_packet, NULL, wtvfile_seek);
     if (!pb) {
         av_free(buffer);
         av_free(wf->sectors);
         av_free(wf);
     }
     return pb;
 }
 
 /**
  * Open file using filename
  * @param[in]  buf       directory buffer
  * @param      buf_size  directory buffer size
  * @param[in]  filename
  * @param      filename_size size of filename
  * @return NULL on error
  */

 static AVIOContext * wtvfile_open2(AVFormatContext *s, const uint8_t *buf, int buf_size, const uint8_t *filename, int filename_size)

 {

     const uint8_t *buf_end = buf + buf_size;
 
     while(buf + 48 <= buf_end) {
         int dir_length, name_size, first_sector, depth;
         uint64_t file_length;
         const uint8_t *name;

         if (ff_guidcmp(buf, ff_dir_entry_guid)) {

             av_log(s, AV_LOG_ERROR, "unknown guid "FF_PRI_GUID", expected dir_entry_guid; "
                    "remaining directory entries ignored\n", FF_ARG_GUID(buf));

             break;
         }
         dir_length  = AV_RL16(buf + 16);
         file_length = AV_RL64(buf + 24);
         name_size   = 2 * AV_RL32(buf + 32);

         if (name_size < 0) {
             av_log(s, AV_LOG_ERROR,
                    "bad filename length, remaining directory entries ignored\n");
             break;
         }
         if (48 + (int64_t)name_size > buf_end - buf) {

             av_log(s, AV_LOG_ERROR, "filename exceeds buffer size; remaining directory entries ignored\n");
             break;
         }
         first_sector = AV_RL32(buf + 40 + name_size);
         depth        = AV_RL32(buf + 44 + name_size);
 
         /* compare file name; test optional null terminator */
         name = buf + 40;
         if (name_size >= filename_size &&
             !memcmp(name, filename, filename_size) &&
             (name_size < filename_size + 2 || !AV_RN16(name + filename_size)))
             return wtvfile_open_sector(first_sector, file_length, depth, s);
 
         buf += dir_length;
     }
     return 0;

 }
 

 #define wtvfile_open(s, buf, buf_size, filename) \
     wtvfile_open2(s, buf, buf_size, filename, sizeof(filename))
 
 /**
  * Close file opened with wtvfile_open_sector(), or wtv_open()
  */

 static void wtvfile_close(AVIOContext *pb)

 {
     WtvFile *wf = pb->opaque;
     av_free(wf->sectors);

     av_freep(&pb->opaque);
     av_freep(&pb->buffer);

     av_free(pb);
 }
 
 /*
  *
  * Main demuxer
  *
  */
 
 typedef struct {
     int seen_data;
 } WtvStream;
 
 typedef struct {

     AVIOContext *pb;       /**< timeline file */

     int64_t epoch;

     int64_t pts;             /**< pts for next data chunk */
     int64_t last_valid_pts;  /**< latest valid pts, used for interative seeking */

 
     /* maintain private seek index, as the AVIndexEntry->pos is relative to the
        start of the 'timeline' file, not the file system (AVFormatContext->pb) */
     AVIndexEntry *index_entries;
     int nb_index_entries;
     unsigned int index_entries_allocated_size;
 } WtvContext;
 

 /* WTV GUIDs */

 static const ff_asf_guid EVENTID_SubtitleSpanningEvent =

     {0x48,0xC0,0xCE,0x5D,0xB9,0xD0,0x63,0x41,0x87,0x2C,0x4F,0x32,0x22,0x3B,0xE8,0x8A};

 static const ff_asf_guid EVENTID_LanguageSpanningEvent =

     {0x6D,0x66,0x92,0xE2,0x02,0x9C,0x8D,0x44,0xAA,0x8D,0x78,0x1A,0x93,0xFD,0xC3,0x95};

 static const ff_asf_guid EVENTID_AudioDescriptorSpanningEvent =
     {0x1C,0xD4,0x7B,0x10,0xDA,0xA6,0x91,0x46,0x83,0x69,0x11,0xB2,0xCD,0xAA,0x28,0x8E};
 static const ff_asf_guid EVENTID_CtxADescriptorSpanningEvent =
     {0xE6,0xA2,0xB4,0x3A,0x47,0x42,0x34,0x4B,0x89,0x6C,0x30,0xAF,0xA5,0xD2,0x1C,0x24};
 static const ff_asf_guid EVENTID_CSDescriptorSpanningEvent =
     {0xD9,0x79,0xE7,0xEf,0xF0,0x97,0x86,0x47,0x80,0x0D,0x95,0xCF,0x50,0x5D,0xDC,0x66};

 static const ff_asf_guid EVENTID_DVBScramblingControlSpanningEvent =
     {0xC4,0xE1,0xD4,0x4B,0xA1,0x90,0x09,0x41,0x82,0x36,0x27,0xF0,0x0E,0x7D,0xCC,0x5B};

 static const ff_asf_guid EVENTID_StreamIDSpanningEvent =
     {0x68,0xAB,0xF1,0xCA,0x53,0xE1,0x41,0x4D,0xA6,0xB3,0xA7,0xC9,0x98,0xDB,0x75,0xEE};
 static const ff_asf_guid EVENTID_TeletextSpanningEvent =
     {0x50,0xD9,0x99,0x95,0x33,0x5F,0x17,0x46,0xAF,0x7C,0x1E,0x54,0xB5,0x10,0xDA,0xA3};

 static const ff_asf_guid EVENTID_AudioTypeSpanningEvent =
     {0xBE,0xBF,0x1C,0x50,0x49,0xB8,0xCE,0x42,0x9B,0xE9,0x3D,0xB8,0x69,0xFB,0x82,0xB3};

 
 /* Windows media GUIDs */
 
 /* Media types */
 static const ff_asf_guid mediasubtype_mpeg1payload =
     {0x81,0xEB,0x36,0xE4,0x4F,0x52,0xCE,0x11,0x9F,0x53,0x00,0x20,0xAF,0x0B,0xA7,0x70};
 static const ff_asf_guid mediatype_mpeg2_sections =
     {0x6C,0x17,0x5F,0x45,0x06,0x4B,0xCE,0x47,0x9A,0xEF,0x8C,0xAE,0xF7,0x3D,0xF7,0xB5};
 static const ff_asf_guid mediatype_mpeg2_pes =
     {0x20,0x80,0x6D,0xE0,0x46,0xDB,0xCF,0x11,0xB4,0xD1,0x00,0x80,0x5F,0x6C,0xBB,0xEA};
 static const ff_asf_guid mediatype_mstvcaption =
     {0x89,0x8A,0x8B,0xB8,0x49,0xB0,0x80,0x4C,0xAD,0xCF,0x58,0x98,0x98,0x5E,0x22,0xC1};
 
 /* Media subtypes */
 static const ff_asf_guid mediasubtype_dvb_subtitle =
     {0xC3,0xCB,0xFF,0x34,0xB3,0xD5,0x71,0x41,0x90,0x02,0xD4,0xC6,0x03,0x01,0x69,0x7F};
 static const ff_asf_guid mediasubtype_teletext =
     {0xE3,0x76,0x2A,0xF7,0x0A,0xEB,0xD0,0x11,0xAC,0xE4,0x00,0x00,0xC0,0xCC,0x16,0xBA};
 static const ff_asf_guid mediasubtype_dtvccdata =
     {0xAA,0xDD,0x2A,0xF5,0xF0,0x36,0xF5,0x43,0x95,0xEA,0x6D,0x86,0x64,0x84,0x26,0x2A};
 static const ff_asf_guid mediasubtype_mpeg2_sections =
     {0x79,0x85,0x9F,0x4A,0xF8,0x6B,0x92,0x43,0x8A,0x6D,0xD2,0xDD,0x09,0xFA,0x78,0x61};
 
 static int read_probe(AVProbeData *p)
 {

     return ff_guidcmp(p->buf, ff_wtv_guid) ? 0 : AVPROBE_SCORE_MAX;

 }
 
 /**

  * Convert win32 FILETIME to ISO-8601 string

  * @return <0 on error

  */

 static int filetime_to_iso8601(char *buf, int buf_size, int64_t value)

 {
     time_t t = (value / 10000000LL) - 11644473600LL;

     struct tm *tm = gmtime(&t);

     if (!tm)
         return -1;
     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
     return 0;

 }
 
 /**
  * Convert crazy time (100ns since 1 Jan 0001) to ISO-8601 string

  * @return <0 on error

  */

 static int crazytime_to_iso8601(char *buf, int buf_size, int64_t value)

 {
     time_t t = (value / 10000000LL) - 719162LL*86400LL;

     struct tm *tm = gmtime(&t);

     if (!tm)
         return -1;
     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", gmtime(&t));
     return 0;

 }
 
 /**
  * Convert OLE DATE to ISO-8601 string

  * @return <0 on error

  */

 static int oledate_to_iso8601(char *buf, int buf_size, int64_t value)

 {

     time_t t = (av_int2double(value) - 25569.0) * 86400;

     struct tm *result= gmtime(&t);
     if (!result)

         return -1;

     strftime(buf, buf_size, "%Y-%m-%d %H:%M:%S", result);

     return 0;

 }
 

 static void get_attachment(AVFormatContext *s, AVIOContext *pb, int length)

 {
     char mime[1024];
     char description[1024];
     unsigned int filesize;
     AVStream *st;

     int ret;

     int64_t pos = avio_tell(pb);

 
     avio_get_str16le(pb, INT_MAX, mime, sizeof(mime));
     if (strcmp(mime, "image/jpeg"))
         goto done;
 

     avio_r8(pb);

     avio_get_str16le(pb, INT_MAX, description, sizeof(description));

     filesize = avio_rl32(pb);

     if (!filesize)
         goto done;
 

     st = avformat_new_stream(s, NULL);

     if (!st)
         goto done;

     av_dict_set(&st->metadata, "title", description, 0);

     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

     st->codec->codec_id   = AV_CODEC_ID_MJPEG;

     st->id = -1;

     ret = av_get_packet(pb, &st->attached_pic, filesize);
     if (ret < 0)

         goto done;

     st->attached_pic.stream_index = st->index;
     st->attached_pic.flags       |= AV_PKT_FLAG_KEY;
     st->disposition              |= AV_DISPOSITION_ATTACHED_PIC;

 done:

     avio_seek(pb, pos + length, SEEK_SET);

 }
 

 static void get_tag(AVFormatContext *s, AVIOContext *pb, const char *key, int type, int length)

 {

     int buf_size;
     char *buf;

     if (!strcmp(key, "WM/MediaThumbType")) {
         avio_skip(pb, length);
         return;

     }
 
     buf_size = FFMAX(2*length, LEN_PRETTY_GUID) + 1;
     buf = av_malloc(buf_size);
     if (!buf)
         return;
 
     if (type == 0 && length == 4) {

         snprintf(buf, buf_size, "%"PRIi32, avio_rl32(pb));

     } else if (type == 1) {
         avio_get_str16le(pb, length, buf, buf_size);
         if (!strlen(buf)) {
            av_free(buf);
            return;
         }
     } else if (type == 3 && length == 4) {

         strcpy(buf, avio_rl32(pb) ? "true" : "false");

     } else if (type == 4 && length == 8) {

         int64_t num = avio_rl64(pb);

         if (!strcmp(key, "WM/EncodingTime") ||

             !strcmp(key, "WM/MediaOriginalBroadcastDateTime")) {

             if (filetime_to_iso8601(buf, buf_size, num) < 0) {
                 av_free(buf);
                 return;
             }

         } else if (!strcmp(key, "WM/WMRVEncodeTime") ||
                    !strcmp(key, "WM/WMRVEndTime")) {

             if (crazytime_to_iso8601(buf, buf_size, num) < 0) {
                 av_free(buf);
                 return;
             }

         } else if (!strcmp(key, "WM/WMRVExpirationDate")) {

             if (oledate_to_iso8601(buf, buf_size, num) < 0 ) {
                 av_free(buf);
                 return;
             }
         } else if (!strcmp(key, "WM/WMRVBitrate"))

             snprintf(buf, buf_size, "%f", av_int2double(num));

         else
             snprintf(buf, buf_size, "%"PRIi64, num);
     } else if (type == 5 && length == 2) {

         snprintf(buf, buf_size, "%u", avio_rl16(pb));

     } else if (type == 6 && length == 16) {
         ff_asf_guid guid;

         avio_read(pb, guid, 16);

         snprintf(buf, buf_size, PRI_PRETTY_GUID, ARG_PRETTY_GUID(guid));
     } else if (type == 2 && !strcmp(key, "WM/Picture")) {
         get_attachment(s, pb, length);
         av_freep(&buf);
         return;
     } else {
         av_freep(&buf);
         av_log(s, AV_LOG_WARNING, "unsupported metadata entry; key:%s, type:%d, length:0x%x\n", key, type, length);

         avio_skip(pb, length);

         return;
     }
 

     av_dict_set(&s->metadata, key, buf, 0);

     av_freep(&buf);
 }
 
 /**
  * Parse metadata entries
  */

 static void parse_legacy_attrib(AVFormatContext *s, AVIOContext *pb)

 {
     ff_asf_guid guid;
     int length, type;
     while(!url_feof(pb)) {
         char key[1024];
         ff_get_guid(pb, &guid);

         type   = avio_rl32(pb);
         length = avio_rl32(pb);

         if (!length)
             break;

         if (ff_guidcmp(&guid, ff_metadata_guid)) {

             av_log(s, AV_LOG_WARNING, "unknown guid "FF_PRI_GUID", expected metadata_guid; "
                    "remaining metadata entries ignored\n", FF_ARG_GUID(guid));

             break;
         }
         avio_get_str16le(pb, INT_MAX, key, sizeof(key));
         get_tag(s, pb, key, type, length);
     }
 
     ff_metadata_conv(&s->metadata, NULL, ff_asf_metadata_conv);
 }
 
 /**

  * parse VIDEOINFOHEADER2 structure
  * @return bytes consumed
  */
 static int parse_videoinfoheader2(AVFormatContext *s, AVStream *st)
 {

     WtvContext *wtv = s->priv_data;

     AVIOContext *pb = wtv->pb;

     avio_skip(pb, 72);  // picture aspect ratio is unreliable

     ff_get_bmp_header(pb, st, NULL);

 
     return 72 + 40;
 }
 
 /**
  * Parse MPEG1WAVEFORMATEX extradata structure
  */
 static void parse_mpeg1waveformatex(AVStream *st)
 {
     /* fwHeadLayer */
     switch (AV_RL16(st->codec->extradata)) {

     case 0x0001 : st->codec->codec_id = AV_CODEC_ID_MP1; break;
     case 0x0002 : st->codec->codec_id = AV_CODEC_ID_MP2; break;
     case 0x0004 : st->codec->codec_id = AV_CODEC_ID_MP3; break;

     }
 
     st->codec->bit_rate = AV_RL32(st->codec->extradata + 2); /* dwHeadBitrate */
 
     /* dwHeadMode */
     switch (AV_RL16(st->codec->extradata + 6)) {

     case 1 :
     case 2 :
     case 4 : st->codec->channels       = 2;
              st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
              break;
     case 8 : st->codec->channels       = 1;
              st->codec->channel_layout = AV_CH_LAYOUT_MONO;
              break;

     }
 }
 

 /**
  * Initialise stream
  * @param st Stream to initialise, or NULL to create and initialise new stream
  * @return NULL on error
  */
 static AVStream * new_stream(AVFormatContext *s, AVStream *st, int sid, int codec_type)

 {

     if (st) {
         if (st->codec->extradata) {
             av_freep(&st->codec->extradata);
             st->codec->extradata_size = 0;
         }
     } else {

         WtvStream *wst = av_mallocz(sizeof(WtvStream));
         if (!wst)
             return NULL;

         st = avformat_new_stream(s, NULL);

         if (!st) {
             av_free(wst);

             return NULL;

         }

         st->id = sid;

         st->priv_data = wst;

     }

     st->codec->codec_type = codec_type;
     st->need_parsing      = AVSTREAM_PARSE_FULL;

     avpriv_set_pts_info(st, 64, 1, 10000000);

     return st;
 }
 
 /**

  * parse Media Type structure and populate stream
  * @param st         Stream, or NULL to create new stream

  * @param mediatype  Mediatype GUID
  * @param subtype    Subtype GUID
  * @param formattype Format GUID
  * @param size       Size of format buffer
  * @return NULL on error
  */

 static AVStream * parse_media_type(AVFormatContext *s, AVStream *st, int sid,

                                    ff_asf_guid mediatype, ff_asf_guid subtype,
                                    ff_asf_guid formattype, int size)
 {

     WtvContext *wtv = s->priv_data;

     AVIOContext *pb = wtv->pb;

     if (!ff_guidcmp(subtype, ff_mediasubtype_cpfilters_processed) &&
         !ff_guidcmp(formattype, ff_format_cpfilters_processed)) {

         ff_asf_guid actual_subtype;
         ff_asf_guid actual_formattype;
 
         if (size < 32) {
             av_log(s, AV_LOG_WARNING, "format buffer size underflow\n");

             avio_skip(pb, size);

             return NULL;
         }
 

         avio_skip(pb, size - 32);

         ff_get_guid(pb, &actual_subtype);
         ff_get_guid(pb, &actual_formattype);

         avio_seek(pb, -size, SEEK_CUR);

         st = parse_media_type(s, st, sid, mediatype, actual_subtype, actual_formattype, size - 32);

         avio_skip(pb, 32);

         return st;

     } else if (!ff_guidcmp(mediatype, ff_mediatype_audio)) {

         st = new_stream(s, st, sid, AVMEDIA_TYPE_AUDIO);

         if (!st)
             return NULL;

         if (!ff_guidcmp(formattype, ff_format_waveformatex)) {

             int ret = ff_get_wav_header(pb, st->codec, size);
             if (ret < 0)
                 return NULL;

         } else {

             if (ff_guidcmp(formattype, ff_format_none))

                 av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));

             avio_skip(pb, size);

         }
 

         if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {

             st->codec->codec_id = ff_wav_codec_get_id(AV_RL32(subtype), st->codec->bits_per_coded_sample);
         } else if (!ff_guidcmp(subtype, mediasubtype_mpeg1payload)) {
             if (st->codec->extradata && st->codec->extradata_size >= 22)
                 parse_mpeg1waveformatex(st);
             else
                 av_log(s, AV_LOG_WARNING, "MPEG1WAVEFORMATEX underflow\n");
         } else {

             st->codec->codec_id = ff_codec_guid_get_id(ff_codec_wav_guids, subtype);

             if (st->codec->codec_id == AV_CODEC_ID_NONE)

                 av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID"\n", FF_ARG_GUID(subtype));

         }
         return st;

     } else if (!ff_guidcmp(mediatype, ff_mediatype_video)) {

         st = new_stream(s, st, sid, AVMEDIA_TYPE_VIDEO);

         if (!st)
             return NULL;

         if (!ff_guidcmp(formattype, ff_format_videoinfo2)) {

             int consumed = parse_videoinfoheader2(s, st);

             avio_skip(pb, FFMAX(size - consumed, 0));

         } else if (!ff_guidcmp(formattype, ff_format_mpeg2_video)) {

             int consumed = parse_videoinfoheader2(s, st);

             avio_skip(pb, FFMAX(size - consumed, 0));

         } else {

             if (ff_guidcmp(formattype, ff_format_none))

                 av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));

             avio_skip(pb, size);

         }
 

         if (!memcmp(subtype + 4, (const uint8_t[]){FF_MEDIASUBTYPE_BASE_GUID}, 12)) {

             st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, AV_RL32(subtype));
         } else {

             st->codec->codec_id = ff_codec_guid_get_id(ff_video_guids, subtype);

         }

         if (st->codec->codec_id == AV_CODEC_ID_NONE)

             av_log(s, AV_LOG_WARNING, "unknown subtype:"FF_PRI_GUID"\n", FF_ARG_GUID(subtype));

         return st;
     } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_pes) &&
                !ff_guidcmp(subtype, mediasubtype_dvb_subtitle)) {

         st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);

         if (!st)
             return NULL;

         if (ff_guidcmp(formattype, ff_format_none))

             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));

         avio_skip(pb, size);

         st->codec->codec_id = AV_CODEC_ID_DVB_SUBTITLE;

         return st;
     } else if (!ff_guidcmp(mediatype, mediatype_mstvcaption) &&
                (!ff_guidcmp(subtype, mediasubtype_teletext) || !ff_guidcmp(subtype, mediasubtype_dtvccdata))) {

         st = new_stream(s, st, sid, AVMEDIA_TYPE_SUBTITLE);

         if (!st)
             return NULL;

         if (ff_guidcmp(formattype, ff_format_none))

             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));

         avio_skip(pb, size);

         st->codec->codec_id = !ff_guidcmp(subtype, mediasubtype_teletext) ? AV_CODEC_ID_DVB_TELETEXT : AV_CODEC_ID_EIA_608;

         return st;
     } else if (!ff_guidcmp(mediatype, mediatype_mpeg2_sections) &&
                !ff_guidcmp(subtype, mediasubtype_mpeg2_sections)) {

         if (ff_guidcmp(formattype, ff_format_none))

             av_log(s, AV_LOG_WARNING, "unknown formattype:"FF_PRI_GUID"\n", FF_ARG_GUID(formattype));

         avio_skip(pb, size);

         return NULL;
     }
 

     av_log(s, AV_LOG_WARNING, "unknown media type, mediatype:"FF_PRI_GUID
                               ", subtype:"FF_PRI_GUID", formattype:"FF_PRI_GUID"\n",
                               FF_ARG_GUID(mediatype), FF_ARG_GUID(subtype), FF_ARG_GUID(formattype));

     avio_skip(pb, size);

     return NULL;
 }
 
 enum {
     SEEK_TO_DATA = 0,
     SEEK_TO_PTS,
 };
 
 /**
  * Parse WTV chunks

  * @param mode SEEK_TO_DATA or SEEK_TO_PTS
  * @param seekts timestamp

  * @param[out] len_ptr Length of data chunk

  * @return stream index of data chunk, or <0 on error
  */
 static int parse_chunks(AVFormatContext *s, int mode, int64_t seekts, int *len_ptr)
 {
     WtvContext *wtv = s->priv_data;

     AVIOContext *pb = wtv->pb;

     while (!url_feof(pb)) {
         ff_asf_guid g;
         int len, sid, consumed;
 
         ff_get_guid(pb, &g);

         len = avio_rl32(pb);

         if (len < 32)
             break;

         sid = avio_rl32(pb) & 0x7FFF;

         avio_skip(pb, 8);

         consumed = 32;
 

         if (!ff_guidcmp(g, ff_SBE2_STREAM_DESC_EVENT)) {

             if (ff_find_stream_index(s, sid) < 0) {
                 ff_asf_guid mediatype, subtype, formattype;
                 int size;

                 avio_skip(pb, 28);

                 ff_get_guid(pb, &mediatype);
                 ff_get_guid(pb, &subtype);

                 avio_skip(pb, 12);

                 ff_get_guid(pb, &formattype);

                 size = avio_rl32(pb);

                 parse_media_type(s, 0, sid, mediatype, subtype, formattype, size);
                 consumed += 92 + size;

             }

         } else if (!ff_guidcmp(g, ff_stream2_guid)) {

             int stream_index = ff_find_stream_index(s, sid);

             if (stream_index >= 0 && s->streams[stream_index]->priv_data && !((WtvStream*)s->streams[stream_index]->priv_data)->seen_data) {

                 ff_asf_guid mediatype, subtype, formattype;
                 int size;

                 avio_skip(pb, 12);

                 ff_get_guid(pb, &mediatype);
                 ff_get_guid(pb, &subtype);

                 avio_skip(pb, 12);

                 ff_get_guid(pb, &formattype);

                 size = avio_rl32(pb);

                 parse_media_type(s, s->streams[stream_index], sid, mediatype, subtype, formattype, size);
                 consumed += 76 + size;
             }

         } else if (!ff_guidcmp(g, EVENTID_AudioDescriptorSpanningEvent) ||
                    !ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
                    !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent) ||
                    !ff_guidcmp(g, EVENTID_StreamIDSpanningEvent) ||
                    !ff_guidcmp(g, EVENTID_SubtitleSpanningEvent) ||
                    !ff_guidcmp(g, EVENTID_TeletextSpanningEvent)) {

             int stream_index = ff_find_stream_index(s, sid);
             if (stream_index >= 0) {
                 AVStream *st = s->streams[stream_index];

                 uint8_t buf[258];
                 const uint8_t *pbuf = buf;
                 int buf_size;
 

                 avio_skip(pb, 8);

                 consumed += 8;
                 if (!ff_guidcmp(g, EVENTID_CtxADescriptorSpanningEvent) ||
                     !ff_guidcmp(g, EVENTID_CSDescriptorSpanningEvent)) {

                     avio_skip(pb, 6);

                     consumed += 6;
                 }

                 buf_size = FFMIN(len - consumed, sizeof(buf));

                 avio_read(pb, buf, buf_size);

                 consumed += buf_size;

                 ff_parse_mpeg2_descriptor(s, st, 0, &pbuf, buf + buf_size, NULL, 0, 0, NULL);

             }

         } else if (!ff_guidcmp(g, EVENTID_AudioTypeSpanningEvent)) {
             int stream_index = ff_find_stream_index(s, sid);
             if (stream_index >= 0) {
                 AVStream *st = s->streams[stream_index];
                 int audio_type;

                 avio_skip(pb, 8);

                 audio_type = avio_r8(pb);

                 if (audio_type == 2)
                     st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
                 else if (audio_type == 3)
                     st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
                 consumed += 9;
             }

         } else if (!ff_guidcmp(g, EVENTID_DVBScramblingControlSpanningEvent)) {
             int stream_index = ff_find_stream_index(s, sid);
             if (stream_index >= 0) {

                 avio_skip(pb, 12);

                 if (avio_rl32(pb))

                     av_log(s, AV_LOG_WARNING, "DVB scrambled stream detected (st:%d), decoding will likely fail\n", stream_index);
                 consumed += 16;
             }

         } else if (!ff_guidcmp(g, EVENTID_LanguageSpanningEvent)) {

             int stream_index = ff_find_stream_index(s, sid);
             if (stream_index >= 0) {
                 AVStream *st = s->streams[stream_index];

                 uint8_t language[4];

                 avio_skip(pb, 12);

                 avio_read(pb, language, 3);

                 if (language[0]) {
                     language[3] = 0;

                     av_dict_set(&st->metadata, "language", language, 0);

                     if (!strcmp(language, "nar") || !strcmp(language, "NAR"))
                         st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;

                 }

                 consumed += 15;
             }

         } else if (!ff_guidcmp(g, ff_timestamp_guid)) {

             int stream_index = ff_find_stream_index(s, sid);
             if (stream_index >= 0) {

                 avio_skip(pb, 8);

                 wtv->pts = avio_rl64(pb);

                 consumed += 16;
                 if (wtv->pts == -1)
                     wtv->pts = AV_NOPTS_VALUE;

                 else {
                     wtv->last_valid_pts = wtv->pts;
                     if (wtv->epoch == AV_NOPTS_VALUE || wtv->pts < wtv->epoch)
                         wtv->epoch = wtv->pts;

                 if (mode == SEEK_TO_PTS && wtv->pts >= seekts) {

                     avio_skip(pb, WTV_PAD8(len) - consumed);

                     return 0;
                 }

                 }

             }

         } else if (!ff_guidcmp(g, ff_data_guid)) {

             int stream_index = ff_find_stream_index(s, sid);

             if (mode == SEEK_TO_DATA && stream_index >= 0 && len > 32 && s->streams[stream_index]->priv_data) {

                 WtvStream *wst = s->streams[stream_index]->priv_data;
                 wst->seen_data = 1;

                 if (len_ptr) {
                     *len_ptr = len;
                 }
                 return stream_index;
             }

         } else if (!ff_guidcmp(g, /* DSATTRIB_WMDRMProtectionInfo */ (const ff_asf_guid){0x83,0x95,0x74,0x40,0x9D,0x6B,0xEC,0x4E,0xB4,0x3C,0x67,0xA1,0x80,0x1E,0x1A,0x9B})) {
             int stream_index = ff_find_stream_index(s, sid);
             if (stream_index >= 0)
                 av_log(s, AV_LOG_WARNING, "encrypted stream detected (st:%d), decoding will likely fail\n", stream_index);

         } else if (
             !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}) ||

             !ff_guidcmp(g, /* DSATTRIB_PBDATAG_ATTRIBUTE */ (const ff_asf_guid){0x79,0x66,0xB5,0xE0,0xB9,0x12,0xCC,0x43,0xB7,0xDF,0x57,0x8C,0xAA,0x5A,0x7B,0x63}) ||

             !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}) ||

             !ff_guidcmp(g, /* DSATTRIB_TRANSPORT_PROPERTIES */ ff_DSATTRIB_TRANSPORT_PROPERTIES) ||

             !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}) ||
             !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}) ||
             !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}) ||
             !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}) ||
             !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}) ||
             !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}) ||
             !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}) ||
             !ff_guidcmp(g, (const ff_asf_guid){0x1E,0xBE,0xC3,0xC5,0x43,0x92,0xDC,0x11,0x85,0xE5,0x00,0x12,0x3F,0x6F,0x73,0xB9}) ||
             !ff_guidcmp(g, (const ff_asf_guid){0x3B,0x86,0xA2,0xB1,0xEB,0x1E,0xC3,0x44,0x8C,0x88,0x1C,0xA3,0xFF,0xE3,0xE7,0x6A}) ||
             !ff_guidcmp(g, (const ff_asf_guid){0x4E,0x7F,0x4C,0x5B,0xC4,0xD0,0x38,0x4B,0xA8,0x3E,0x21,0x7F,0x7B,0xBF,0x52,0xE7}) ||
             !ff_guidcmp(g, (const ff_asf_guid){0x63,0x36,0xEB,0xFE,0xA1,0x7E,0xD9,0x11,0x83,0x08,0x00,0x07,0xE9,0x5E,0xAD,0x8D}) ||
             !ff_guidcmp(g, (const ff_asf_guid){0x70,0xE9,0xF1,0xF8,0x89,0xA4,0x4C,0x4D,0x83,0x73,0xB8,0x12,0xE0,0xD5,0xF8,0x1E}) ||

             !ff_guidcmp(g, ff_index_guid) ||
             !ff_guidcmp(g, ff_sync_guid) ||
             !ff_guidcmp(g, ff_stream1_guid) ||

             !ff_guidcmp(g, (const ff_asf_guid){0xF7,0x10,0x02,0xB9,0xEE,0x7C,0xED,0x4E,0xBD,0x7F,0x05,0x40,0x35,0x86,0x18,0xA1})) {

             //ignore known guids
         } else

             av_log(s, AV_LOG_WARNING, "unsupported chunk:"FF_PRI_GUID"\n", FF_ARG_GUID(g));

         avio_skip(pb, WTV_PAD8(len) - consumed);

     }
     return AVERROR_EOF;
 }
 

 static int read_header(AVFormatContext *s)

 {

     WtvContext *wtv = s->priv_data;
     int root_sector, root_size;
     uint8_t root[WTV_SECTOR_SIZE];

     AVIOContext *pb;

     int64_t timeline_pos;

     int ret;
 

     wtv->epoch          =
     wtv->pts            =
     wtv->last_valid_pts = AV_NOPTS_VALUE;
 
     /* read root directory sector */

     avio_skip(s->pb, 0x30);

     root_size = avio_rl32(s->pb);

     if (root_size > sizeof(root)) {
         av_log(s, AV_LOG_ERROR, "root directory size exceeds sector size\n");
         return AVERROR_INVALIDDATA;
     }

     avio_skip(s->pb, 4);

     root_sector = avio_rl32(s->pb);

     seek_by_sector(s->pb, root_sector, 0);

     root_size = avio_read(s->pb, root, root_size);

     if (root_size < 0)
         return AVERROR_INVALIDDATA;
 
     /* parse chunks up until first data chunk */

     wtv->pb = wtvfile_open(s, root, root_size, ff_timeline_le16);

     if (!wtv->pb) {
         av_log(s, AV_LOG_ERROR, "timeline data missing\n");
         return AVERROR_INVALIDDATA;
     }
 

     ret = parse_chunks(s, SEEK_TO_DATA, 0, 0);
     if (ret < 0)
         return ret;

     avio_seek(wtv->pb, -32, SEEK_CUR);

     timeline_pos = avio_tell(s->pb); // save before opening another file

 
     /* read metadata */

     pb = wtvfile_open(s, root, root_size, ff_table_0_entries_legacy_attrib_le16);

     if (pb) {
         parse_legacy_attrib(s, pb);
         wtvfile_close(pb);
     }
 
     /* read seek index */
     if (s->nb_streams) {
         AVStream *st = s->streams[0];

         pb = wtvfile_open(s, root, root_size, ff_table_0_entries_time_le16);

         if (pb) {
             while(1) {

                 uint64_t timestamp = avio_rl64(pb);
                 uint64_t frame_nb  = avio_rl64(pb);

                 if (url_feof(pb))
                     break;
                 ff_add_index_entry(&wtv->index_entries, &wtv->nb_index_entries, &wtv->index_entries_allocated_size,
                                    0, timestamp, frame_nb, 0, AVINDEX_KEYFRAME);
             }
             wtvfile_close(pb);

             if (wtv->nb_index_entries) {

                 pb = wtvfile_open(s, root, root_size, ff_timeline_table_0_entries_Events_le16);

                 if (pb) {
                     int i;
                     while (1) {

                         uint64_t frame_nb = avio_rl64(pb);
                         uint64_t position = avio_rl64(pb);

                         if (url_feof(pb))
                             break;
                         for (i = wtv->nb_index_entries - 1; i >= 0; i--) {
                             AVIndexEntry *e = wtv->index_entries + i;
                             if (frame_nb > e->size)
                                 break;
                             if (position > e->pos)
                                 e->pos = position;
                         }
                     }
                     wtvfile_close(pb);
                     st->duration = wtv->index_entries[wtv->nb_index_entries - 1].timestamp;
                 }
             }
         }
     }
 

     avio_seek(s->pb, timeline_pos, SEEK_SET);

     return 0;
 }
 
 static int read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     WtvContext *wtv = s->priv_data;

     AVIOContext *pb = wtv->pb;

     int stream_index, len, ret;
 
     stream_index = parse_chunks(s, SEEK_TO_DATA, 0, &len);
     if (stream_index < 0)
         return stream_index;
 
     ret = av_get_packet(pb, pkt, len - 32);
     if (ret < 0)
         return ret;
     pkt->stream_index = stream_index;
     pkt->pts          = wtv->pts;

     avio_skip(pb, WTV_PAD8(len) - len);

     return 0;
 }
 

 static int read_seek(AVFormatContext *s, int stream_index,
                      int64_t ts, int flags)

 {
     WtvContext *wtv = s->priv_data;

     AVIOContext *pb = wtv->pb;

     AVStream *st = s->streams[0];
     int64_t ts_relative;

     int i;
 

     if ((flags & AVSEEK_FLAG_FRAME) || (flags & AVSEEK_FLAG_BYTE))

         return AVERROR(ENOSYS);

 
     /* timestamp adjustment is required because wtv->pts values are absolute,
      * whereas AVIndexEntry->timestamp values are relative to epoch. */
     ts_relative = ts;
     if (wtv->epoch != AV_NOPTS_VALUE)
         ts_relative -= wtv->epoch;
 
     i = ff_index_search_timestamp(wtv->index_entries, wtv->nb_index_entries, ts_relative, flags);
     if (i < 0) {

         if (wtv->last_valid_pts == AV_NOPTS_VALUE || ts < wtv->last_valid_pts) {
             if (avio_seek(pb, 0, SEEK_SET) < 0)
                 return -1;
         } else if (st->duration != AV_NOPTS_VALUE && ts_relative > st->duration && wtv->nb_index_entries) {
             if (avio_seek(pb, wtv->index_entries[wtv->nb_index_entries - 1].pos, SEEK_SET) < 0)
                 return -1;
         }

         if (parse_chunks(s, SEEK_TO_PTS, ts, 0) < 0)

             return AVERROR(ERANGE);
         return 0;
     }

     if (avio_seek(pb, wtv->index_entries[i].pos, SEEK_SET) < 0)
         return -1;

     wtv->pts = wtv->index_entries[i].timestamp;
     if (wtv->epoch != AV_NOPTS_VALUE)
         wtv->pts += wtv->epoch;
     wtv->last_valid_pts = wtv->pts;
     return 0;
 }
 
 static int read_close(AVFormatContext *s)
 {
     WtvContext *wtv = s->priv_data;

     av_freep(&wtv->index_entries);

     wtvfile_close(wtv->pb);
     return 0;

 }
 

 AVInputFormat ff_wtv_demuxer = {

     .name           = "wtv",
     .long_name      = NULL_IF_CONFIG_SMALL("Windows Television (WTV)"),
     .priv_data_size = sizeof(WtvContext),
     .read_probe     = read_probe,
     .read_header    = read_header,
     .read_packet    = read_packet,

     .read_seek      = read_seek,
     .read_close     = read_close,
     .flags          = AVFMT_SHOW_IDS,

 };