text: /*
   * Apple HTTP Live Streaming demuxer
   * Copyright (c) 2010 Martin Storsjo
   * Copyright (c) 2013 Anssi Hannula
   *
   * 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
   * Apple HTTP Live Streaming demuxer
   * http://tools.ietf.org/html/draft-pantos-http-live-streaming
   */
  
  #include "libavformat/http.h"
  #include "libavutil/avstring.h"
  #include "libavutil/avassert.h"
  #include "libavutil/intreadwrite.h"
  #include "libavutil/mathematics.h"
  #include "libavutil/opt.h"
  #include "libavutil/dict.h"
  #include "libavutil/time.h"
  #include "avformat.h"
  #include "internal.h"
  #include "avio_internal.h"
  #include "id3v2.h"
  
  #define INITIAL_BUFFER_SIZE 32768
  
  #define MAX_FIELD_LEN 64
  #define MAX_CHARACTERISTICS_LEN 512
  
  #define MPEG_TIME_BASE 90000
  #define MPEG_TIME_BASE_Q (AVRational){1, MPEG_TIME_BASE}
  
  /*
   * An apple http stream consists of a playlist with media segment files,
   * played sequentially. There may be several playlists with the same
   * video content, in different bandwidth variants, that are played in
   * parallel (preferably only one bandwidth variant at a time). In this case,
   * the user supplied the url to a main playlist that only lists the variant
   * playlists.
   *
   * If the main playlist doesn't point at any variants, we still create
   * one anonymous toplevel variant for this, to maintain the structure.
   */
  
  enum KeyType {
      KEY_NONE,
      KEY_AES_128,
      KEY_SAMPLE_AES
  };
  
  struct segment {
      int64_t duration;
      int64_t url_offset;
      int64_t size;
      char *url;
      char *key;
      enum KeyType key_type;
      uint8_t iv[16];
      /* associated Media Initialization Section, treated as a segment */
      struct segment *init_section;
  };
  
  struct rendition;
  
  enum PlaylistType {
      PLS_TYPE_UNSPECIFIED,
      PLS_TYPE_EVENT,
      PLS_TYPE_VOD
  };
  
  /*
   * Each playlist has its own demuxer. If it currently is active,
   * it has an open AVIOContext too, and potentially an AVPacket
   * containing the next packet from this stream.
   */
  struct playlist {
      char url[MAX_URL_SIZE];
      AVIOContext pb;
      uint8_t* read_buffer;
      AVIOContext *input;
      int input_read_done;
      AVIOContext *input_next;
      int input_next_requested;
      AVFormatContext *parent;
      int index;
      AVFormatContext *ctx;
      AVPacket pkt;
      int has_noheader_flag;
  
      /* main demuxer streams associated with this playlist
       * indexed by the subdemuxer stream indexes */
      AVStream **main_streams;
      int n_main_streams;
  
      int finished;
      enum PlaylistType type;
      int64_t target_duration;
      int start_seq_no;
      int n_segments;
      struct segment **segments;
      int needed;
      int cur_seq_no;
      int64_t cur_seg_offset;
      int64_t last_load_time;
  
      /* Currently active Media Initialization Section */
      struct segment *cur_init_section;
      uint8_t *init_sec_buf;
      unsigned int init_sec_buf_size;
      unsigned int init_sec_data_len;
      unsigned int init_sec_buf_read_offset;
  
      char key_url[MAX_URL_SIZE];
      uint8_t key[16];
  
      /* ID3 timestamp handling (elementary audio streams have ID3 timestamps
       * (and possibly other ID3 tags) in the beginning of each segment) */
      int is_id3_timestamped; /* -1: not yet known */
      int64_t id3_mpegts_timestamp; /* in mpegts tb */
      int64_t id3_offset; /* in stream original tb */
      uint8_t* id3_buf; /* temp buffer for id3 parsing */
      unsigned int id3_buf_size;
      AVDictionary *id3_initial; /* data from first id3 tag */
      int id3_found; /* ID3 tag found at some point */
      int id3_changed; /* ID3 tag data has changed at some point */
      ID3v2ExtraMeta *id3_deferred_extra; /* stored here until subdemuxer is opened */
  
      int64_t seek_timestamp;
      int seek_flags;
      int seek_stream_index; /* into subdemuxer stream array */
  
      /* Renditions associated with this playlist, if any.
       * Alternative rendition playlists have a single rendition associated
       * with them, and variant main Media Playlists may have
       * multiple (playlist-less) renditions associated with them. */
      int n_renditions;
      struct rendition **renditions;
  
      /* Media Initialization Sections (EXT-X-MAP) associated with this
       * playlist, if any. */
      int n_init_sections;
      struct segment **init_sections;
  };
  
  /*
   * Renditions are e.g. alternative subtitle or audio streams.
   * The rendition may either be an external playlist or it may be
   * contained in the main Media Playlist of the variant (in which case
   * playlist is NULL).
   */
  struct rendition {
      enum AVMediaType type;
      struct playlist *playlist;
      char group_id[MAX_FIELD_LEN];
      char language[MAX_FIELD_LEN];
      char name[MAX_FIELD_LEN];
      int disposition;
  };
  
  struct variant {
      int bandwidth;
  
      /* every variant contains at least the main Media Playlist in index 0 */
      int n_playlists;
      struct playlist **playlists;
  
      char audio_group[MAX_FIELD_LEN];
      char video_group[MAX_FIELD_LEN];
      char subtitles_group[MAX_FIELD_LEN];
  };
  
  typedef struct HLSContext {
      AVClass *class;
      AVFormatContext *ctx;
      int n_variants;
      struct variant **variants;
      int n_playlists;
      struct playlist **playlists;
      int n_renditions;
      struct rendition **renditions;
  
      int cur_seq_no;
      int live_start_index;
      int first_packet;
      int64_t first_timestamp;
      int64_t cur_timestamp;
      AVIOInterruptCB *interrupt_callback;
      char *referer;                       ///< holds HTTP referer set as an AVOption to the HTTP protocol context
      char *user_agent;                    ///< holds HTTP user agent set as an AVOption to the HTTP protocol context
      char *cookies;                       ///< holds HTTP cookie values set in either the initial response or as an AVOption to the HTTP protocol context
      char *headers;                       ///< holds HTTP headers set as an AVOption to the HTTP protocol context
      char *http_proxy;                    ///< holds the address of the HTTP proxy server
      AVDictionary *avio_opts;
      int strict_std_compliance;
      char *allowed_extensions;
      int max_reload;
      int http_persistent;
      int http_multiple;
      AVIOContext *playlist_pb;
  } HLSContext;
  
  static void free_segment_list(struct playlist *pls)
  {
      int i;
      for (i = 0; i < pls->n_segments; i++) {
          av_freep(&pls->segments[i]->key);
          av_freep(&pls->segments[i]->url);
          av_freep(&pls->segments[i]);
      }
      av_freep(&pls->segments);
      pls->n_segments = 0;
  }
  
  static void free_init_section_list(struct playlist *pls)
  {
      int i;
      for (i = 0; i < pls->n_init_sections; i++) {
          av_freep(&pls->init_sections[i]->url);
          av_freep(&pls->init_sections[i]);
      }
      av_freep(&pls->init_sections);
      pls->n_init_sections = 0;
  }
  
  static void free_playlist_list(HLSContext *c)
  {
      int i;
      for (i = 0; i < c->n_playlists; i++) {
          struct playlist *pls = c->playlists[i];
          free_segment_list(pls);
          free_init_section_list(pls);
          av_freep(&pls->main_streams);
          av_freep(&pls->renditions);
          av_freep(&pls->id3_buf);
          av_dict_free(&pls->id3_initial);
          ff_id3v2_free_extra_meta(&pls->id3_deferred_extra);
          av_freep(&pls->init_sec_buf);
          av_packet_unref(&pls->pkt);
          av_freep(&pls->pb.buffer);
          if (pls->input)
              ff_format_io_close(c->ctx, &pls->input);
          pls->input_read_done = 0;
          if (pls->input_next)
              ff_format_io_close(c->ctx, &pls->input_next);
          pls->input_next_requested = 0;
          if (pls->ctx) {
              pls->ctx->pb = NULL;
              avformat_close_input(&pls->ctx);
          }
          av_free(pls);
      }
      av_freep(&c->playlists);
      av_freep(&c->cookies);
      av_freep(&c->user_agent);
      av_freep(&c->headers);
      av_freep(&c->http_proxy);
      c->n_playlists = 0;
  }
  
  static void free_variant_list(HLSContext *c)
  {
      int i;
      for (i = 0; i < c->n_variants; i++) {
          struct variant *var = c->variants[i];
          av_freep(&var->playlists);
          av_free(var);
      }
      av_freep(&c->variants);
      c->n_variants = 0;
  }
  
  static void free_rendition_list(HLSContext *c)
  {
      int i;
      for (i = 0; i < c->n_renditions; i++)
          av_freep(&c->renditions[i]);
      av_freep(&c->renditions);
      c->n_renditions = 0;
  }
  
  /*
   * Used to reset a statically allocated AVPacket to a clean slate,
   * containing no data.
   */
  static void reset_packet(AVPacket *pkt)
  {
      av_init_packet(pkt);
      pkt->data = NULL;
  }
  
  static struct playlist *new_playlist(HLSContext *c, const char *url,
                                       const char *base)
  {
      struct playlist *pls = av_mallocz(sizeof(struct playlist));
      if (!pls)
          return NULL;
      reset_packet(&pls->pkt);
      ff_make_absolute_url(pls->url, sizeof(pls->url), base, url);
      pls->seek_timestamp = AV_NOPTS_VALUE;
  
      pls->is_id3_timestamped = -1;
      pls->id3_mpegts_timestamp = AV_NOPTS_VALUE;
  
      dynarray_add(&c->playlists, &c->n_playlists, pls);
      return pls;
  }
  
  struct variant_info {
      char bandwidth[20];
      /* variant group ids: */
      char audio[MAX_FIELD_LEN];
      char video[MAX_FIELD_LEN];
      char subtitles[MAX_FIELD_LEN];
  };
  
  static struct variant *new_variant(HLSContext *c, struct variant_info *info,
                                     const char *url, const char *base)
  {
      struct variant *var;
      struct playlist *pls;
  
      pls = new_playlist(c, url, base);
      if (!pls)
          return NULL;
  
      var = av_mallocz(sizeof(struct variant));
      if (!var)
          return NULL;
  
      if (info) {
          var->bandwidth = atoi(info->bandwidth);
          strcpy(var->audio_group, info->audio);
          strcpy(var->video_group, info->video);
          strcpy(var->subtitles_group, info->subtitles);
      }
  
      dynarray_add(&c->variants, &c->n_variants, var);
      dynarray_add(&var->playlists, &var->n_playlists, pls);
      return var;
  }
  
  static void handle_variant_args(struct variant_info *info, const char *key,
                                  int key_len, char **dest, int *dest_len)
  {
      if (!strncmp(key, "BANDWIDTH=", key_len)) {
          *dest     =        info->bandwidth;
          *dest_len = sizeof(info->bandwidth);
      } else if (!strncmp(key, "AUDIO=", key_len)) {
          *dest     =        info->audio;
          *dest_len = sizeof(info->audio);
      } else if (!strncmp(key, "VIDEO=", key_len)) {
          *dest     =        info->video;
          *dest_len = sizeof(info->video);
      } else if (!strncmp(key, "SUBTITLES=", key_len)) {
          *dest     =        info->subtitles;
          *dest_len = sizeof(info->subtitles);
      }
  }
  
  struct key_info {
       char uri[MAX_URL_SIZE];
       char method[11];
       char iv[35];
  };
  
  static void handle_key_args(struct key_info *info, const char *key,
                              int key_len, char **dest, int *dest_len)
  {
      if (!strncmp(key, "METHOD=", key_len)) {
          *dest     =        info->method;
          *dest_len = sizeof(info->method);
      } else if (!strncmp(key, "URI=", key_len)) {
          *dest     =        info->uri;
          *dest_len = sizeof(info->uri);
      } else if (!strncmp(key, "IV=", key_len)) {
          *dest     =        info->iv;
          *dest_len = sizeof(info->iv);
      }
  }
  
  struct init_section_info {
      char uri[MAX_URL_SIZE];
      char byterange[32];
  };
  
  static struct segment *new_init_section(struct playlist *pls,
                                          struct init_section_info *info,
                                          const char *url_base)
  {
      struct segment *sec;
      char *ptr;
      char tmp_str[MAX_URL_SIZE];
  
      if (!info->uri[0])
          return NULL;
  
      sec = av_mallocz(sizeof(*sec));
      if (!sec)
          return NULL;
  
      ff_make_absolute_url(tmp_str, sizeof(tmp_str), url_base, info->uri);
      sec->url = av_strdup(tmp_str);
      if (!sec->url) {
          av_free(sec);
          return NULL;
      }
  
      if (info->byterange[0]) {
          sec->size = strtoll(info->byterange, NULL, 10);
          ptr = strchr(info->byterange, '@');
          if (ptr)
              sec->url_offset = strtoll(ptr+1, NULL, 10);
      } else {
          /* the entire file is the init section */
          sec->size = -1;
      }
  
      dynarray_add(&pls->init_sections, &pls->n_init_sections, sec);
  
      return sec;
  }
  
  static void handle_init_section_args(struct init_section_info *info, const char *key,
                                             int key_len, char **dest, int *dest_len)
  {
      if (!strncmp(key, "URI=", key_len)) {
          *dest     =        info->uri;
          *dest_len = sizeof(info->uri);
      } else if (!strncmp(key, "BYTERANGE=", key_len)) {
          *dest     =        info->byterange;
          *dest_len = sizeof(info->byterange);
      }
  }
  
  struct rendition_info {
      char type[16];
      char uri[MAX_URL_SIZE];
      char group_id[MAX_FIELD_LEN];
      char language[MAX_FIELD_LEN];
      char assoc_language[MAX_FIELD_LEN];
      char name[MAX_FIELD_LEN];
      char defaultr[4];
      char forced[4];
      char characteristics[MAX_CHARACTERISTICS_LEN];
  };
  
  static struct rendition *new_rendition(HLSContext *c, struct rendition_info *info,
                                        const char *url_base)
  {
      struct rendition *rend;
      enum AVMediaType type = AVMEDIA_TYPE_UNKNOWN;
      char *characteristic;
      char *chr_ptr;
      char *saveptr;
  
      if (!strcmp(info->type, "AUDIO"))
          type = AVMEDIA_TYPE_AUDIO;
      else if (!strcmp(info->type, "VIDEO"))
          type = AVMEDIA_TYPE_VIDEO;
      else if (!strcmp(info->type, "SUBTITLES"))
          type = AVMEDIA_TYPE_SUBTITLE;
      else if (!strcmp(info->type, "CLOSED-CAPTIONS"))
          /* CLOSED-CAPTIONS is ignored since we do not support CEA-608 CC in
           * AVC SEI RBSP anyway */
          return NULL;
  
      if (type == AVMEDIA_TYPE_UNKNOWN)
          return NULL;
  
      /* URI is mandatory for subtitles as per spec */
      if (type == AVMEDIA_TYPE_SUBTITLE && !info->uri[0])
          return NULL;
  
      /* TODO: handle subtitles (each segment has to parsed separately) */
      if (c->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL)
          if (type == AVMEDIA_TYPE_SUBTITLE)
              return NULL;
  
      rend = av_mallocz(sizeof(struct rendition));
      if (!rend)
          return NULL;
  
      dynarray_add(&c->renditions, &c->n_renditions, rend);
  
      rend->type = type;
      strcpy(rend->group_id, info->group_id);
      strcpy(rend->language, info->language);
      strcpy(rend->name, info->name);
  
      /* add the playlist if this is an external rendition */
      if (info->uri[0]) {
          rend->playlist = new_playlist(c, info->uri, url_base);
          if (rend->playlist)
              dynarray_add(&rend->playlist->renditions,
                           &rend->playlist->n_renditions, rend);
      }
  
      if (info->assoc_language[0]) {
          int langlen = strlen(rend->language);
          if (langlen < sizeof(rend->language) - 3) {
              rend->language[langlen] = ',';
              strncpy(rend->language + langlen + 1, info->assoc_language,
                      sizeof(rend->language) - langlen - 2);
          }
      }
  
      if (!strcmp(info->defaultr, "YES"))
          rend->disposition |= AV_DISPOSITION_DEFAULT;
      if (!strcmp(info->forced, "YES"))
          rend->disposition |= AV_DISPOSITION_FORCED;
  
      chr_ptr = info->characteristics;
      while ((characteristic = av_strtok(chr_ptr, ",", &saveptr))) {
          if (!strcmp(characteristic, "public.accessibility.describes-music-and-sound"))
              rend->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
          else if (!strcmp(characteristic, "public.accessibility.describes-video"))
              rend->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
  
          chr_ptr = NULL;
      }
  
      return rend;
  }
  
  static void handle_rendition_args(struct rendition_info *info, const char *key,
                                    int key_len, char **dest, int *dest_len)
  {
      if (!strncmp(key, "TYPE=", key_len)) {
          *dest     =        info->type;
          *dest_len = sizeof(info->type);
      } else if (!strncmp(key, "URI=", key_len)) {
          *dest     =        info->uri;
          *dest_len = sizeof(info->uri);
      } else if (!strncmp(key, "GROUP-ID=", key_len)) {
          *dest     =        info->group_id;
          *dest_len = sizeof(info->group_id);
      } else if (!strncmp(key, "LANGUAGE=", key_len)) {
          *dest     =        info->language;
          *dest_len = sizeof(info->language);
      } else if (!strncmp(key, "ASSOC-LANGUAGE=", key_len)) {
          *dest     =        info->assoc_language;
          *dest_len = sizeof(info->assoc_language);
      } else if (!strncmp(key, "NAME=", key_len)) {
          *dest     =        info->name;
          *dest_len = sizeof(info->name);
      } else if (!strncmp(key, "DEFAULT=", key_len)) {
          *dest     =        info->defaultr;
          *dest_len = sizeof(info->defaultr);
      } else if (!strncmp(key, "FORCED=", key_len)) {
          *dest     =        info->forced;
          *dest_len = sizeof(info->forced);
      } else if (!strncmp(key, "CHARACTERISTICS=", key_len)) {
          *dest     =        info->characteristics;
          *dest_len = sizeof(info->characteristics);
      }
      /*
       * ignored:
       * - AUTOSELECT: client may autoselect based on e.g. system language
       * - INSTREAM-ID: EIA-608 closed caption number ("CC1".."CC4")
       */
  }
  
  /* used by parse_playlist to allocate a new variant+playlist when the
   * playlist is detected to be a Media Playlist (not Master Playlist)
   * and we have no parent Master Playlist (parsing of which would have
   * allocated the variant and playlist already)
   * *pls == NULL  => Master Playlist or parentless Media Playlist
   * *pls != NULL => parented Media Playlist, playlist+variant allocated */
  static int ensure_playlist(HLSContext *c, struct playlist **pls, const char *url)
  {
      if (*pls)
          return 0;
      if (!new_variant(c, NULL, url, NULL))
          return AVERROR(ENOMEM);
      *pls = c->playlists[c->n_playlists - 1];
      return 0;
  }
  
  static void update_options(char **dest, const char *name, void *src)
  {
      av_freep(dest);
      av_opt_get(src, name, AV_OPT_SEARCH_CHILDREN, (uint8_t**)dest);
      if (*dest && !strlen(*dest))
          av_freep(dest);
  }
  
  static int open_url_keepalive(AVFormatContext *s, AVIOContext **pb,
                                const char *url)
  {
  #if !CONFIG_HTTP_PROTOCOL
      return AVERROR_PROTOCOL_NOT_FOUND;
  #else
      int ret;
      URLContext *uc = ffio_geturlcontext(*pb);
      av_assert0(uc);
      (*pb)->eof_reached = 0;
      ret = ff_http_do_new_request(uc, url);
      if (ret < 0) {
          ff_format_io_close(s, pb);
      }
      return ret;
  #endif
  }
  
  static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
                      AVDictionary *opts, AVDictionary *opts2, int *is_http_out)
  {
      HLSContext *c = s->priv_data;
      AVDictionary *tmp = NULL;
      const char *proto_name = NULL;
      int ret;
      int is_http = 0;
  
      av_dict_copy(&tmp, opts, 0);
      av_dict_copy(&tmp, opts2, 0);
  
      if (av_strstart(url, "crypto", NULL)) {
          if (url[6] == '+' || url[6] == ':')
              proto_name = avio_find_protocol_name(url + 7);
      }
  
      if (!proto_name)
          proto_name = avio_find_protocol_name(url);
  
      if (!proto_name)
          return AVERROR_INVALIDDATA;
  
      // only http(s) & file are allowed
      if (av_strstart(proto_name, "file", NULL)) {
          if (strcmp(c->allowed_extensions, "ALL") && !av_match_ext(url, c->allowed_extensions)) {
              av_log(s, AV_LOG_ERROR,
                  "Filename extension of \'%s\' is not a common multimedia extension, blocked for security reasons.\n"
                  "If you wish to override this adjust allowed_extensions, you can set it to \'ALL\' to allow all\n",
                  url);
              return AVERROR_INVALIDDATA;
          }
      } else if (av_strstart(proto_name, "http", NULL)) {
          is_http = 1;
      } else
          return AVERROR_INVALIDDATA;
  
      if (!strncmp(proto_name, url, strlen(proto_name)) && url[strlen(proto_name)] == ':')
          ;
      else if (av_strstart(url, "crypto", NULL) && !strncmp(proto_name, url + 7, strlen(proto_name)) && url[7 + strlen(proto_name)] == ':')
          ;
      else if (strcmp(proto_name, "file") || !strncmp(url, "file,", 5))
          return AVERROR_INVALIDDATA;
  
      if (is_http && c->http_persistent && *pb) {
          ret = open_url_keepalive(c->ctx, pb, url);
          if (ret == AVERROR_EXIT) {
              return ret;
          } else if (ret < 0) {
              if (ret != AVERROR_EOF)
                  av_log(s, AV_LOG_WARNING,
                      "keepalive request failed for '%s', retrying with new connection: %s\n",
                      url, av_err2str(ret));
              ret = s->io_open(s, pb, url, AVIO_FLAG_READ, &tmp);
          }
      } else {
          ret = s->io_open(s, pb, url, AVIO_FLAG_READ, &tmp);
      }
      if (ret >= 0) {
          // update cookies on http response with setcookies.
          char *new_cookies = NULL;
  
          if (!(s->flags & AVFMT_FLAG_CUSTOM_IO))
              av_opt_get(*pb, "cookies", AV_OPT_SEARCH_CHILDREN, (uint8_t**)&new_cookies);
  
          if (new_cookies) {
              av_free(c->cookies);
              c->cookies = new_cookies;
          }
  
          av_dict_set(&opts, "cookies", c->cookies, 0);
      }
  
      av_dict_free(&tmp);
  
      if (is_http_out)
          *is_http_out = is_http;
  
      return ret;
  }
  
  static int parse_playlist(HLSContext *c, const char *url,
                            struct playlist *pls, AVIOContext *in)
  {
      int ret = 0, is_segment = 0, is_variant = 0;
      int64_t duration = 0;
      enum KeyType key_type = KEY_NONE;
      uint8_t iv[16] = "";
      int has_iv = 0;
      char key[MAX_URL_SIZE] = "";
      char line[MAX_URL_SIZE];
      const char *ptr;
      int close_in = 0;
      int64_t seg_offset = 0;
      int64_t seg_size = -1;
      uint8_t *new_url = NULL;
      struct variant_info variant_info;
      char tmp_str[MAX_URL_SIZE];
      struct segment *cur_init_section = NULL;
      int is_http = av_strstart(url, "http", NULL);
  
      if (is_http && !in && c->http_persistent && c->playlist_pb) {
          in = c->playlist_pb;
          ret = open_url_keepalive(c->ctx, &c->playlist_pb, url);
          if (ret == AVERROR_EXIT) {
              return ret;
          } else if (ret < 0) {
              if (ret != AVERROR_EOF)
                  av_log(c->ctx, AV_LOG_WARNING,
                      "keepalive request failed for '%s', retrying with new connection: %s\n",
                      url, av_err2str(ret));
              in = NULL;
          }
      }
  
      if (!in) {
          AVDictionary *opts = NULL;
          /* Some HLS servers don't like being sent the range header */
          av_dict_set(&opts, "seekable", "0", 0);
  
          // broker prior HTTP options that should be consistent across requests
          av_dict_set(&opts, "user_agent", c->user_agent, 0);
          av_dict_set(&opts, "cookies", c->cookies, 0);
          av_dict_set(&opts, "headers", c->headers, 0);
          av_dict_set(&opts, "http_proxy", c->http_proxy, 0);
  
          if (c->http_persistent)
              av_dict_set(&opts, "multiple_requests", "1", 0);
  
          ret = c->ctx->io_open(c->ctx, &in, url, AVIO_FLAG_READ, &opts);
          av_dict_free(&opts);
          if (ret < 0)
              return ret;
  
          if (is_http && c->http_persistent)
              c->playlist_pb = in;
          else
              close_in = 1;
      }
  
      if (av_opt_get(in, "location", AV_OPT_SEARCH_CHILDREN, &new_url) >= 0)
          url = new_url;
  
      ff_get_chomp_line(in, line, sizeof(line));
      if (strcmp(line, "#EXTM3U")) {
          ret = AVERROR_INVALIDDATA;
          goto fail;
      }
  
      if (pls) {
          free_segment_list(pls);
          pls->finished = 0;
          pls->type = PLS_TYPE_UNSPECIFIED;
      }
      while (!avio_feof(in)) {
          ff_get_chomp_line(in, line, sizeof(line));
          if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
              is_variant = 1;
              memset(&variant_info, 0, sizeof(variant_info));
              ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
                                 &variant_info);
          } else if (av_strstart(line, "#EXT-X-KEY:", &ptr)) {
              struct key_info info = {{0}};
              ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_key_args,
                                 &info);
              key_type = KEY_NONE;
              has_iv = 0;
              if (!strcmp(info.method, "AES-128"))
                  key_type = KEY_AES_128;
              if (!strcmp(info.method, "SAMPLE-AES"))
                  key_type = KEY_SAMPLE_AES;
              if (!strncmp(info.iv, "0x", 2) || !strncmp(info.iv, "0X", 2)) {
                  ff_hex_to_data(iv, info.iv + 2);
                  has_iv = 1;
              }
              av_strlcpy(key, info.uri, sizeof(key));
          } else if (av_strstart(line, "#EXT-X-MEDIA:", &ptr)) {
              struct rendition_info info = {{0}};
              ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_rendition_args,
                                 &info);
              new_rendition(c, &info, url);
          } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
              ret = ensure_playlist(c, &pls, url);
              if (ret < 0)
                  goto fail;
              pls->target_duration = strtoll(ptr, NULL, 10) * AV_TIME_BASE;
          } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
              ret = ensure_playlist(c, &pls, url);
              if (ret < 0)
                  goto fail;
              pls->start_seq_no = atoi(ptr);
          } else if (av_strstart(line, "#EXT-X-PLAYLIST-TYPE:", &ptr)) {
              ret = ensure_playlist(c, &pls, url);
              if (ret < 0)
                  goto fail;
              if (!strcmp(ptr, "EVENT"))
                  pls->type = PLS_TYPE_EVENT;
              else if (!strcmp(ptr, "VOD"))
                  pls->type = PLS_TYPE_VOD;
          } else if (av_strstart(line, "#EXT-X-MAP:", &ptr)) {
              struct init_section_info info = {{0}};
              ret = ensure_playlist(c, &pls, url);
              if (ret < 0)
                  goto fail;
              ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_init_section_args,
                                 &info);
              cur_init_section = new_init_section(pls, &info, url);
          } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
              if (pls)
                  pls->finished = 1;
          } else if (av_strstart(line, "#EXTINF:", &ptr)) {
              is_segment = 1;
              duration   = atof(ptr) * AV_TIME_BASE;
          } else if (av_strstart(line, "#EXT-X-BYTERANGE:", &ptr)) {
              seg_size = strtoll(ptr, NULL, 10);
              ptr = strchr(ptr, '@');
              if (ptr)
                  seg_offset = strtoll(ptr+1, NULL, 10);
          } else if (av_strstart(line, "#", NULL)) {
              continue;
          } else if (line[0]) {
              if (is_variant) {
                  if (!new_variant(c, &variant_info, line, url)) {
                      ret = AVERROR(ENOMEM);
                      goto fail;
                  }
                  is_variant = 0;
              }
              if (is_segment) {
                  struct segment *seg;
                  if (!pls) {
                      if (!new_variant(c, 0, url, NULL)) {
                          ret = AVERROR(ENOMEM);
                          goto fail;
                      }
                      pls = c->playlists[c->n_playlists - 1];
                  }
                  seg = av_malloc(sizeof(struct segment));
                  if (!seg) {
                      ret = AVERROR(ENOMEM);
                      goto fail;
                  }
                  seg->duration = duration;
                  seg->key_type = key_type;
                  if (has_iv) {
                      memcpy(seg->iv, iv, sizeof(iv));
                  } else {
                      int seq = pls->start_seq_no + pls->n_segments;
                      memset(seg->iv, 0, sizeof(seg->iv));
                      AV_WB32(seg->iv + 12, seq);
                  }
  
                  if (key_type != KEY_NONE) {
                      ff_make_absolute_url(tmp_str, sizeof(tmp_str), url, key);
                      seg->key = av_strdup(tmp_str);
                      if (!seg->key) {
                          av_free(seg);
                          ret = AVERROR(ENOMEM);
                          goto fail;
                      }
                  } else {
                      seg->key = NULL;
                  }
  
                  ff_make_absolute_url(tmp_str, sizeof(tmp_str), url, line);
                  seg->url = av_strdup(tmp_str);
                  if (!seg->url) {
                      av_free(seg->key);
                      av_free(seg);
                      ret = AVERROR(ENOMEM);
                      goto fail;
                  }
  
                  dynarray_add(&pls->segments, &pls->n_segments, seg);
                  is_segment = 0;
  
                  seg->size = seg_size;
                  if (seg_size >= 0) {
                      seg->url_offset = seg_offset;
                      seg_offset += seg_size;
                      seg_size = -1;
                  } else {
                      seg->url_offset = 0;
                      seg_offset = 0;
                  }
  
                  seg->init_section = cur_init_section;
              }
          }
      }
      if (pls)
          pls->last_load_time = av_gettime_relative();
  
  fail:
      av_free(new_url);
      if (close_in)
          ff_format_io_close(c->ctx, &in);
      c->ctx->ctx_flags = c->ctx->ctx_flags & ~(unsigned)AVFMTCTX_UNSEEKABLE;
      if (!c->n_variants || !c->variants[0]->n_playlists ||
          !(c->variants[0]->playlists[0]->finished ||
            c->variants[0]->playlists[0]->type == PLS_TYPE_EVENT))
          c->ctx->ctx_flags |= AVFMTCTX_UNSEEKABLE;
      return ret;
  }
  
  static struct segment *current_segment(struct playlist *pls)
  {
      return pls->segments[pls->cur_seq_no - pls->start_seq_no];
  }
  
  static struct segment *next_segment(struct playlist *pls)
  {
      int n = pls->cur_seq_no - pls->start_seq_no + 1;
      if (n >= pls->n_segments)
          return NULL;
      return pls->segments[n];
  }
  
  enum ReadFromURLMode {
      READ_NORMAL,
      READ_COMPLETE,
  };
  
  static int read_from_url(struct playlist *pls, struct segment *seg,
                           uint8_t *buf, int buf_size,
                           enum ReadFromURLMode mode)
  {
      int ret;
  
       /* limit read if the segment was only a part of a file */
      if (seg->size >= 0)
          buf_size = FFMIN(buf_size, seg->size - pls->cur_seg_offset);
  
      if (mode == READ_COMPLETE) {
          ret = avio_read(pls->input, buf, buf_size);
          if (ret != buf_size)
              av_log(NULL, AV_LOG_ERROR, "Could not read complete segment.\n");
      } else
          ret = avio_read(pls->input, buf, buf_size);
  
      if (ret > 0)
          pls->cur_seg_offset += ret;
  
      return ret;
  }
  
  /* Parse the raw ID3 data and pass contents to caller */
  static void parse_id3(AVFormatContext *s, AVIOContext *pb,
                        AVDictionary **metadata, int64_t *dts,
                        ID3v2ExtraMetaAPIC **apic, ID3v2ExtraMeta **extra_meta)
  {
      static const char id3_priv_owner_ts[] = "com.apple.streaming.transportStreamTimestamp";
      ID3v2ExtraMeta *meta;
  
      ff_id3v2_read_dict(pb, metadata, ID3v2_DEFAULT_MAGIC, extra_meta);
      for (meta = *extra_meta; meta; meta = meta->next) {
          if (!strcmp(meta->tag, "PRIV")) {
              ID3v2ExtraMetaPRIV *priv = meta->data;
              if (priv->datasize == 8 && !strcmp(priv->owner, id3_priv_owner_ts)) {
                  /* 33-bit MPEG timestamp */
                  int64_t ts = AV_RB64(priv->data);
                  av_log(s, AV_LOG_DEBUG, "HLS ID3 audio timestamp %"PRId64"\n", ts);
                  if ((ts & ~((1ULL << 33) - 1)) == 0)
                      *dts = ts;
                  else
                      av_log(s, AV_LOG_ERROR, "Invalid HLS ID3 audio timestamp %"PRId64"\n", ts);
              }
          } else if (!strcmp(meta->tag, "APIC") && apic)
              *apic = meta->data;
      }
  }
  
  /* Check if the ID3 metadata contents have changed */
  static int id3_has_changed_values(struct playlist *pls, AVDictionary *metadata,
                                    ID3v2ExtraMetaAPIC *apic)
  {
      AVDictionaryEntry *entry = NULL;
      AVDictionaryEntry *oldentry;
      /* check that no keys have changed values */
      while ((entry = av_dict_get(metadata, "", entry, AV_DICT_IGNORE_SUFFIX))) {
          oldentry = av_dict_get(pls->id3_initial, entry->key, NULL, AV_DICT_MATCH_CASE);
          if (!oldentry || strcmp(oldentry->value, entry->value) != 0)
              return 1;
      }
  
      /* check if apic appeared */
      if (apic && (pls->ctx->nb_streams != 2 || !pls->ctx->streams[1]->attached_pic.data))
          return 1;
  
      if (apic) {
          int size = pls->ctx->streams[1]->attached_pic.size;
          if (size != apic->buf->size - AV_INPUT_BUFFER_PADDING_SIZE)
              return 1;
  
          if (memcmp(apic->buf->data, pls->ctx->streams[1]->attached_pic.data, size) != 0)
              return 1;
      }
  
      return 0;
  }
  
  /* Parse ID3 data and handle the found data */
  static void handle_id3(AVIOContext *pb, struct playlist *pls)
  {
      AVDictionary *metadata = NULL;
      ID3v2ExtraMetaAPIC *apic = NULL;
      ID3v2ExtraMeta *extra_meta = NULL;
      int64_t timestamp = AV_NOPTS_VALUE;
  
      parse_id3(pls->ctx, pb, &metadata, &timestamp, &apic, &extra_meta);
  
      if (timestamp != AV_NOPTS_VALUE) {
          pls->id3_mpegts_timestamp = timestamp;
          pls->id3_offset = 0;
      }
  
      if (!pls->id3_found) {
          /* initial ID3 tags */
          av_assert0(!pls->id3_deferred_extra);
          pls->id3_found = 1;
  
          /* get picture attachment and set text metadata */
          if (pls->ctx->nb_streams)
              ff_id3v2_parse_apic(pls->ctx, &extra_meta);
          else
              /* demuxer not yet opened, defer picture attachment */
              pls->id3_deferred_extra = extra_meta;
  
          ff_id3v2_parse_priv_dict(&metadata, &extra_meta);
          av_dict_copy(&pls->ctx->metadata, metadata, 0);
          pls->id3_initial = metadata;
  
      } else {
          if (!pls->id3_changed && id3_has_changed_values(pls, metadata, apic)) {
              avpriv_report_missing_feature(pls->ctx, "Changing ID3 metadata in HLS audio elementary stream");
              pls->id3_changed = 1;
          }
          av_dict_free(&metadata);
      }
  
      if (!pls->id3_deferred_extra)
          ff_id3v2_free_extra_meta(&extra_meta);
  }
  
  static void intercept_id3(struct playlist *pls, uint8_t *buf,
                           int buf_size, int *len)
  {
      /* intercept id3 tags, we do not want to pass them to the raw
       * demuxer on all segment switches */
      int bytes;
      int id3_buf_pos = 0;
      int fill_buf = 0;
      struct segment *seg = current_segment(pls);
  
      /* gather all the id3 tags */
      while (1) {
          /* see if we can retrieve enough data for ID3 header */
          if (*len < ID3v2_HEADER_SIZE && buf_size >= ID3v2_HEADER_SIZE) {
              bytes = read_from_url(pls, seg, buf + *len, ID3v2_HEADER_SIZE - *len, READ_COMPLETE);
              if (bytes > 0) {
  
                  if (bytes == ID3v2_HEADER_SIZE - *len)
                      /* no EOF yet, so fill the caller buffer again after
                       * we have stripped the ID3 tags */
                      fill_buf = 1;
  
                  *len += bytes;
  
              } else if (*len <= 0) {
                  /* error/EOF */
                  *len = bytes;
                  fill_buf = 0;
              }
          }
  
          if (*len < ID3v2_HEADER_SIZE)
              break;
  
          if (ff_id3v2_match(buf, ID3v2_DEFAULT_MAGIC)) {
              int64_t maxsize = seg->size >= 0 ? seg->size : 1024*1024;
              int taglen = ff_id3v2_tag_len(buf);
              int tag_got_bytes = FFMIN(taglen, *len);
              int remaining = taglen - tag_got_bytes;
  
              if (taglen > maxsize) {
                  av_log(pls->ctx, AV_LOG_ERROR, "Too large HLS ID3 tag (%d > %"PRId64" bytes)\n",
                         taglen, maxsize);
                  break;
              }
  
              /*
               * Copy the id3 tag to our temporary id3 buffer.
               * We could read a small id3 tag directly without memcpy, but
               * we would still need to copy the large tags, and handling
               * both of those cases together with the possibility for multiple
               * tags would make the handling a bit complex.
               */
              pls->id3_buf = av_fast_realloc(pls->id3_buf, &pls->id3_buf_size, id3_buf_pos + taglen);
              if (!pls->id3_buf)
                  break;
              memcpy(pls->id3_buf + id3_buf_pos, buf, tag_got_bytes);
              id3_buf_pos += tag_got_bytes;
  
              /* strip the intercepted bytes */
              *len -= tag_got_bytes;
              memmove(buf, buf + tag_got_bytes, *len);
              av_log(pls->ctx, AV_LOG_DEBUG, "Stripped %d HLS ID3 bytes\n", tag_got_bytes);
  
              if (remaining > 0) {
                  /* read the rest of the tag in */
                  if (read_from_url(pls, seg, pls->id3_buf + id3_buf_pos, remaining, READ_COMPLETE) != remaining)
                      break;
                  id3_buf_pos += remaining;
                  av_log(pls->ctx, AV_LOG_DEBUG, "Stripped additional %d HLS ID3 bytes\n", remaining);
              }
  
          } else {
              /* no more ID3 tags */
              break;
          }
      }
  
      /* re-fill buffer for the caller unless EOF */
      if (*len >= 0 && (fill_buf || *len == 0)) {
          bytes = read_from_url(pls, seg, buf + *len, buf_size - *len, READ_NORMAL);
  
          /* ignore error if we already had some data */
          if (bytes >= 0)
              *len += bytes;
          else if (*len == 0)
              *len = bytes;
      }
  
      if (pls->id3_buf) {
          /* Now parse all the ID3 tags */
          AVIOContext id3ioctx;
          ffio_init_context(&id3ioctx, pls->id3_buf, id3_buf_pos, 0, NULL, NULL, NULL, NULL);
          handle_id3(&id3ioctx, pls);
      }
  
      if (pls->is_id3_timestamped == -1)
          pls->is_id3_timestamped = (pls->id3_mpegts_timestamp != AV_NOPTS_VALUE);
  }
  
  static int open_input(HLSContext *c, struct playlist *pls, struct segment *seg, AVIOContext **in)
  {
      AVDictionary *opts = NULL;
      int ret;
      int is_http = 0;
  
      // broker prior HTTP options that should be consistent across requests
      av_dict_set(&opts, "user_agent", c->user_agent, 0);
      av_dict_set(&opts, "referer", c->referer, 0);
      av_dict_set(&opts, "cookies", c->cookies, 0);
      av_dict_set(&opts, "headers", c->headers, 0);
      av_dict_set(&opts, "http_proxy", c->http_proxy, 0);
      av_dict_set(&opts, "seekable", "0", 0);
  
      if (c->http_persistent)
          av_dict_set(&opts, "multiple_requests", "1", 0);
  
      if (seg->size >= 0) {
          /* try to restrict the HTTP request to the part we want
           * (if this is in fact a HTTP request) */
          av_dict_set_int(&opts, "offset", seg->url_offset, 0);
          av_dict_set_int(&opts, "end_offset", seg->url_offset + seg->size, 0);
      }
  
      av_log(pls->parent, AV_LOG_VERBOSE, "HLS request for url '%s', offset %"PRId64", playlist %d\n",
             seg->url, seg->url_offset, pls->index);
  
      if (seg->key_type == KEY_NONE) {
          ret = open_url(pls->parent, in, seg->url, c->avio_opts, opts, &is_http);
      } else if (seg->key_type == KEY_AES_128) {
          AVDictionary *opts2 = NULL;
          char iv[33], key[33], url[MAX_URL_SIZE];
          if (strcmp(seg->key, pls->key_url)) {
              AVIOContext *pb = NULL;
              if (open_url(pls->parent, &pb, seg->key, c->avio_opts, opts, NULL) == 0) {
                  ret = avio_read(pb, pls->key, sizeof(pls->key));
                  if (ret != sizeof(pls->key)) {
                      av_log(NULL, AV_LOG_ERROR, "Unable to read key file %s\n",
                             seg->key);
                  }
                  ff_format_io_close(pls->parent, &pb);
              } else {
                  av_log(NULL, AV_LOG_ERROR, "Unable to open key file %s\n",
                         seg->key);
              }
              av_strlcpy(pls->key_url, seg->key, sizeof(pls->key_url));
          }
          ff_data_to_hex(iv, seg->iv, sizeof(seg->iv), 0);
          ff_data_to_hex(key, pls->key, sizeof(pls->key), 0);
          iv[32] = key[32] = '\0';
          if (strstr(seg->url, "://"))
              snprintf(url, sizeof(url), "crypto+%s", seg->url);
          else
              snprintf(url, sizeof(url), "crypto:%s", seg->url);
  
          av_dict_copy(&opts2, c->avio_opts, 0);
          av_dict_set(&opts2, "key", key, 0);
          av_dict_set(&opts2, "iv", iv, 0);
  
          ret = open_url(pls->parent, in, url, opts2, opts, &is_http);
  
          av_dict_free(&opts2);
  
          if (ret < 0) {
              goto cleanup;
          }
          ret = 0;
      } else if (seg->key_type == KEY_SAMPLE_AES) {
          av_log(pls->parent, AV_LOG_ERROR,
                 "SAMPLE-AES encryption is not supported yet\n");
          ret = AVERROR_PATCHWELCOME;
      }
      else
        ret = AVERROR(ENOSYS);
  
      /* Seek to the requested position. If this was a HTTP request, the offset
       * should already be where want it to, but this allows e.g. local testing
       * without a HTTP server.
       *
       * This is not done for HTTP at all as avio_seek() does internal bookkeeping
       * of file offset which is out-of-sync with the actual offset when "offset"
       * AVOption is used with http protocol, causing the seek to not be a no-op
       * as would be expected. Wrong offset received from the server will not be
       * noticed without the call, though.
       */
      if (ret == 0 && !is_http && seg->key_type == KEY_NONE && seg->url_offset) {
          int64_t seekret = avio_seek(*in, seg->url_offset, SEEK_SET);
          if (seekret < 0) {
              av_log(pls->parent, AV_LOG_ERROR, "Unable to seek to offset %"PRId64" of HLS segment '%s'\n", seg->url_offset, seg->url);
              ret = seekret;
              ff_format_io_close(pls->parent, in);
          }
      }
  
  cleanup:
      av_dict_free(&opts);
      pls->cur_seg_offset = 0;
      return ret;
  }
  
  static int update_init_section(struct playlist *pls, struct segment *seg)
  {
      static const int max_init_section_size = 1024*1024;
      HLSContext *c = pls->parent->priv_data;
      int64_t sec_size;
      int64_t urlsize;
      int ret;
  
      if (seg->init_section == pls->cur_init_section)
          return 0;
  
      pls->cur_init_section = NULL;
  
      if (!seg->init_section)
          return 0;
  
      ret = open_input(c, pls, seg->init_section, &pls->input);
      if (ret < 0) {
          av_log(pls->parent, AV_LOG_WARNING,
                 "Failed to open an initialization section in playlist %d\n",
                 pls->index);
          return ret;
      }
  
      if (seg->init_section->size >= 0)
          sec_size = seg->init_section->size;
      else if ((urlsize = avio_size(pls->input)) >= 0)
          sec_size = urlsize;
      else
          sec_size = max_init_section_size;
  
      av_log(pls->parent, AV_LOG_DEBUG,
             "Downloading an initialization section of size %"PRId64"\n",
             sec_size);
  
      sec_size = FFMIN(sec_size, max_init_section_size);
  
      av_fast_malloc(&pls->init_sec_buf, &pls->init_sec_buf_size, sec_size);
  
      ret = read_from_url(pls, seg->init_section, pls->init_sec_buf,
                          pls->init_sec_buf_size, READ_COMPLETE);
      ff_format_io_close(pls->parent, &pls->input);
  
      if (ret < 0)
          return ret;
  
      pls->cur_init_section = seg->init_section;
      pls->init_sec_data_len = ret;
      pls->init_sec_buf_read_offset = 0;
  
      /* spec says audio elementary streams do not have media initialization
       * sections, so there should be no ID3 timestamps */
      pls->is_id3_timestamped = 0;
  
      return 0;
  }
  
  static int64_t default_reload_interval(struct playlist *pls)
  {
      return pls->n_segments > 0 ?
                            pls->segments[pls->n_segments - 1]->duration :
                            pls->target_duration;
  }
  
  static int playlist_needed(struct playlist *pls)
  {
      AVFormatContext *s = pls->parent;
      int i, j;
      int stream_needed = 0;
      int first_st;
  
      /* If there is no context or streams yet, the playlist is needed */
      if (!pls->ctx || !pls->n_main_streams)
          return 1;
  
      /* check if any of the streams in the playlist are needed */
      for (i = 0; i < pls->n_main_streams; i++) {
          if (pls->main_streams[i]->discard < AVDISCARD_ALL) {
              stream_needed = 1;
              break;
          }
      }
  
      /* If all streams in the playlist were discarded, the playlist is not
       * needed (regardless of whether whole programs are discarded or not). */
      if (!stream_needed)
          return 0;
  
      /* Otherwise, check if all the programs (variants) this playlist is in are
       * discarded. Since all streams in the playlist are part of the same programs
       * we can just check the programs of the first stream. */
  
      first_st = pls->main_streams[0]->index;
  
      for (i = 0; i < s->nb_programs; i++) {
          AVProgram *program = s->programs[i];
          if (program->discard < AVDISCARD_ALL) {
              for (j = 0; j < program->nb_stream_indexes; j++) {
                  if (program->stream_index[j] == first_st) {
                      /* playlist is in an undiscarded program */
                      return 1;
                  }
              }
          }
      }
  
      /* some streams were not discarded but all the programs were */
      return 0;
  }
  
  static int read_data(void *opaque, uint8_t *buf, int buf_size)
  {
      struct playlist *v = opaque;
      HLSContext *c = v->parent->priv_data;
      int ret;
      int just_opened = 0;
      int reload_count = 0;
      struct segment *seg;
  
  restart:
      if (!v->needed)
          return AVERROR_EOF;
  
      if (!v->input || (c->http_persistent && v->input_read_done)) {
          int64_t reload_interval;
  
          /* Check that the playlist is still needed before opening a new
           * segment. */
          v->needed = playlist_needed(v);
  
          if (!v->needed) {
              av_log(v->parent, AV_LOG_INFO, "No longer receiving playlist %d\n",
                  v->index);
              return AVERROR_EOF;
          }
  
          /* If this is a live stream and the reload interval has elapsed since
           * the last playlist reload, reload the playlists now. */
          reload_interval = default_reload_interval(v);
  
  reload:
          reload_count++;
          if (reload_count > c->max_reload)
              return AVERROR_EOF;
          if (!v->finished &&
              av_gettime_relative() - v->last_load_time >= reload_interval) {
              if ((ret = parse_playlist(c, v->url, v, NULL)) < 0) {
                  if (ret != AVERROR_EXIT)
                      av_log(v->parent, AV_LOG_WARNING, "Failed to reload playlist %d\n",
                             v->index);
                  return ret;
              }
              /* If we need to reload the playlist again below (if
               * there's still no more segments), switch to a reload
               * interval of half the target duration. */
              reload_interval = v->target_duration / 2;
          }
          if (v->cur_seq_no < v->start_seq_no) {
              av_log(NULL, AV_LOG_WARNING,
                     "skipping %d segments ahead, expired from playlists\n",
                     v->start_seq_no - v->cur_seq_no);
              v->cur_seq_no = v->start_seq_no;
          }
          if (v->cur_seq_no >= v->start_seq_no + v->n_segments) {
              if (v->finished)
                  return AVERROR_EOF;
              while (av_gettime_relative() - v->last_load_time < reload_interval) {
                  if (ff_check_interrupt(c->interrupt_callback))
                      return AVERROR_EXIT;
                  av_usleep(100*1000);
              }
              /* Enough time has elapsed since the last reload */
              goto reload;
          }
  
          v->input_read_done = 0;
          seg = current_segment(v);
  
          /* load/update Media Initialization Section, if any */
          ret = update_init_section(v, seg);
          if (ret)
              return ret;
  
          if (c->http_multiple == 1 && v->input_next_requested) {
              FFSWAP(AVIOContext *, v->input, v->input_next);
              v->input_next_requested = 0;
              ret = 0;
          } else {
              ret = open_input(c, v, seg, &v->input);
          }
          if (ret < 0) {
              if (ff_check_interrupt(c->interrupt_callback))
                  return AVERROR_EXIT;
              av_log(v->parent, AV_LOG_WARNING, "Failed to open segment %d of playlist %d\n",
                     v->cur_seq_no,
                     v->index);
              v->cur_seq_no += 1;
              goto reload;
          }
          just_opened = 1;
      }
  
      if (c->http_multiple == -1) {
          uint8_t *http_version_opt = NULL;
          int r = av_opt_get(v->input, "http_version", AV_OPT_SEARCH_CHILDREN, &http_version_opt);
          if (r >= 0) {
              c->http_multiple = strncmp((const char *)http_version_opt, "1.1", 3) == 0;
              av_freep(&http_version_opt);
          }
      }
  
      seg = next_segment(v);
      if (c->http_multiple == 1 && !v->input_next_requested &&
          seg && seg->key_type == KEY_NONE && av_strstart(seg->url, "http", NULL)) {
          ret = open_input(c, v, seg, &v->input_next);
          if (ret < 0) {
              if (ff_check_interrupt(c->interrupt_callback))
                  return AVERROR_EXIT;
              av_log(v->parent, AV_LOG_WARNING, "Failed to open segment %d of playlist %d\n",
                     v->cur_seq_no + 1,
                     v->index);
          } else {
              v->input_next_requested = 1;
          }
      }
  
      if (v->init_sec_buf_read_offset < v->init_sec_data_len) {
          /* Push init section out first before first actual segment */
          int copy_size = FFMIN(v->init_sec_data_len - v->init_sec_buf_read_offset, buf_size);
          memcpy(buf, v->init_sec_buf, copy_size);
          v->init_sec_buf_read_offset += copy_size;
          return copy_size;
      }
  
      seg = current_segment(v);
      ret = read_from_url(v, seg, buf, buf_size, READ_NORMAL);
      if (ret > 0) {
          if (just_opened && v->is_id3_timestamped != 0) {
              /* Intercept ID3 tags here, elementary audio streams are required
               * to convey timestamps using them in the beginning of each segment. */
              intercept_id3(v, buf, buf_size, &ret);
          }
  
          return ret;
      }
      if (c->http_persistent &&
          seg->key_type == KEY_NONE && av_strstart(seg->url, "http", NULL)) {
          v->input_read_done = 1;
      } else {
          ff_format_io_close(v->parent, &v->input);
      }
      v->cur_seq_no++;
  
      c->cur_seq_no = v->cur_seq_no;
  
      goto restart;
  }
  
  static void add_renditions_to_variant(HLSContext *c, struct variant *var,
                                        enum AVMediaType type, const char *group_id)
  {
      int i;
  
      for (i = 0; i < c->n_renditions; i++) {
          struct rendition *rend = c->renditions[i];
  
          if (rend->type == type && !strcmp(rend->group_id, group_id)) {
  
              if (rend->playlist)
                  /* rendition is an external playlist
                   * => add the playlist to the variant */
                  dynarray_add(&var->playlists, &var->n_playlists, rend->playlist);
              else
                  /* rendition is part of the variant main Media Playlist
                   * => add the rendition to the main Media Playlist */
                  dynarray_add(&var->playlists[0]->renditions,
                               &var->playlists[0]->n_renditions,
                               rend);
          }
      }
  }
  
  static void add_metadata_from_renditions(AVFormatContext *s, struct playlist *pls,
                                           enum AVMediaType type)
  {
      int rend_idx = 0;
      int i;
  
      for (i = 0; i < pls->n_main_streams; i++) {
          AVStream *st = pls->main_streams[i];
  
          if (st->codecpar->codec_type != type)
              continue;
  
          for (; rend_idx < pls->n_renditions; rend_idx++) {
              struct rendition *rend = pls->renditions[rend_idx];
  
              if (rend->type != type)
                  continue;
  
              if (rend->language[0])
                  av_dict_set(&st->metadata, "language", rend->language, 0);
              if (rend->name[0])
                  av_dict_set(&st->metadata, "comment", rend->name, 0);
  
              st->disposition |= rend->disposition;
          }
          if (rend_idx >=pls->n_renditions)
              break;
      }
  }
  
  /* if timestamp was in valid range: returns 1 and sets seq_no
   * if not: returns 0 and sets seq_no to closest segment */
  static int find_timestamp_in_playlist(HLSContext *c, struct playlist *pls,
                                        int64_t timestamp, int *seq_no)
  {
      int i;
      int64_t pos = c->first_timestamp == AV_NOPTS_VALUE ?
                    0 : c->first_timestamp;
  
      if (timestamp < pos) {
          *seq_no = pls->start_seq_no;
          return 0;
      }
  
      for (i = 0; i < pls->n_segments; i++) {
          int64_t diff = pos + pls->segments[i]->duration - timestamp;
          if (diff > 0) {
              *seq_no = pls->start_seq_no + i;
              return 1;
          }
          pos += pls->segments[i]->duration;
      }
  
      *seq_no = pls->start_seq_no + pls->n_segments - 1;
  
      return 0;
  }
  
  static int select_cur_seq_no(HLSContext *c, struct playlist *pls)
  {
      int seq_no;
  
      if (!pls->finished && !c->first_packet &&
          av_gettime_relative() - pls->last_load_time >= default_reload_interval(pls))
          /* reload the playlist since it was suspended */
          parse_playlist(c, pls->url, pls, NULL);
  
      /* If playback is already in progress (we are just selecting a new
       * playlist) and this is a complete file, find the matching segment
       * by counting durations. */
      if (pls->finished && c->cur_timestamp != AV_NOPTS_VALUE) {
          find_timestamp_in_playlist(c, pls, c->cur_timestamp, &seq_no);
          return seq_no;
      }
  
      if (!pls->finished) {
          if (!c->first_packet && /* we are doing a segment selection during playback */
              c->cur_seq_no >= pls->start_seq_no &&
              c->cur_seq_no < pls->start_seq_no + pls->n_segments)
              /* While spec 3.4.3 says that we cannot assume anything about the
               * content at the same sequence number on different playlists,
               * in practice this seems to work and doing it otherwise would
               * require us to download a segment to inspect its timestamps. */
              return c->cur_seq_no;
  
          /* If this is a live stream, start live_start_index segments from the
           * start or end */
          if (c->live_start_index < 0)
              return pls->start_seq_no + FFMAX(pls->n_segments + c->live_start_index, 0);
          else
              return pls->start_seq_no + FFMIN(c->live_start_index, pls->n_segments - 1);
      }
  
      /* Otherwise just start on the first segment. */
      return pls->start_seq_no;
  }
  
  static int save_avio_options(AVFormatContext *s)
  {
      HLSContext *c = s->priv_data;
      static const char * const opts[] = {
          "headers", "http_proxy", "user_agent", "user-agent", "cookies", "referer", NULL };
      const char * const * opt = opts;
      uint8_t *buf;
      int ret = 0;
  
      while (*opt) {
          if (av_opt_get(s->pb, *opt, AV_OPT_SEARCH_CHILDREN | AV_OPT_ALLOW_NULL, &buf) >= 0) {
              ret = av_dict_set(&c->avio_opts, *opt, buf,
                                AV_DICT_DONT_STRDUP_VAL);
              if (ret < 0)
                  return ret;
          }
          opt++;
      }
  
      return ret;
  }
  
  static int nested_io_open(AVFormatContext *s, AVIOContext **pb, const char *url,
                            int flags, AVDictionary **opts)
  {
      av_log(s, AV_LOG_ERROR,
             "A HLS playlist item '%s' referred to an external file '%s'. "
             "Opening this file was forbidden for security reasons\n",
             s->url, url);
      return AVERROR(EPERM);
  }
  
  static void add_stream_to_programs(AVFormatContext *s, struct playlist *pls, AVStream *stream)
  {
      HLSContext *c = s->priv_data;
      int i, j;
      int bandwidth = -1;
  
      for (i = 0; i < c->n_variants; i++) {
          struct variant *v = c->variants[i];
  
          for (j = 0; j < v->n_playlists; j++) {
              if (v->playlists[j] != pls)
                  continue;
  
              av_program_add_stream_index(s, i, stream->index);
  
              if (bandwidth < 0)
                  bandwidth = v->bandwidth;
              else if (bandwidth != v->bandwidth)
                  bandwidth = -1; /* stream in multiple variants with different bandwidths */
          }
      }
  
      if (bandwidth >= 0)
          av_dict_set_int(&stream->metadata, "variant_bitrate", bandwidth, 0);
  }
  
  static int set_stream_info_from_input_stream(AVStream *st, struct playlist *pls, AVStream *ist)
  {
      int err;
  
      err = avcodec_parameters_copy(st->codecpar, ist->codecpar);
      if (err < 0)
          return err;
  
      if (pls->is_id3_timestamped) /* custom timestamps via id3 */
          avpriv_set_pts_info(st, 33, 1, MPEG_TIME_BASE);
      else
          avpriv_set_pts_info(st, ist->pts_wrap_bits, ist->time_base.num, ist->time_base.den);
  
      st->internal->need_context_update = 1;
  
      return 0;
  }
  
  /* add new subdemuxer streams to our context, if any */
  static int update_streams_from_subdemuxer(AVFormatContext *s, struct playlist *pls)
  {
      int err;
  
      while (pls->n_main_streams < pls->ctx->nb_streams) {
          int ist_idx = pls->n_main_streams;
          AVStream *st = avformat_new_stream(s, NULL);
          AVStream *ist = pls->ctx->streams[ist_idx];
  
          if (!st)
              return AVERROR(ENOMEM);
  
          st->id = pls->index;
          dynarray_add(&pls->main_streams, &pls->n_main_streams, st);
  
          add_stream_to_programs(s, pls, st);
  
          err = set_stream_info_from_input_stream(st, pls, ist);
          if (err < 0)
              return err;
      }
  
      return 0;
  }
  
  static void update_noheader_flag(AVFormatContext *s)
  {
      HLSContext *c = s->priv_data;
      int flag_needed = 0;
      int i;
  
      for (i = 0; i < c->n_playlists; i++) {
          struct playlist *pls = c->playlists[i];
  
          if (pls->has_noheader_flag) {
              flag_needed = 1;
              break;
          }
      }
  
      if (flag_needed)
          s->ctx_flags |= AVFMTCTX_NOHEADER;
      else
          s->ctx_flags &= ~AVFMTCTX_NOHEADER;
  }
  
  static int hls_close(AVFormatContext *s)
  {
      HLSContext *c = s->priv_data;
  
      free_playlist_list(c);
      free_variant_list(c);
      free_rendition_list(c);
  
      av_dict_free(&c->avio_opts);
      ff_format_io_close(c->ctx, &c->playlist_pb);
  
      return 0;
  }
  
  static int hls_read_header(AVFormatContext *s)
  {
      void *u = (s->flags & AVFMT_FLAG_CUSTOM_IO) ? NULL : s->pb;
      HLSContext *c = s->priv_data;
      int ret = 0, i;
      int highest_cur_seq_no = 0;
  
      c->ctx                = s;
      c->interrupt_callback = &s->interrupt_callback;
      c->strict_std_compliance = s->strict_std_compliance;
  
      c->first_packet = 1;
      c->first_timestamp = AV_NOPTS_VALUE;
      c->cur_timestamp = AV_NOPTS_VALUE;
  
      if (u) {
          // get the previous user agent & set back to null if string size is zero
          update_options(&c->user_agent, "user_agent", u);
  
          // get the previous cookies & set back to null if string size is zero
          update_options(&c->cookies, "cookies", u);
  
          // get the previous headers & set back to null if string size is zero
          update_options(&c->headers, "headers", u);
  
          // get the previous http proxt & set back to null if string size is zero
          update_options(&c->http_proxy, "http_proxy", u);
      }
  
      if ((ret = parse_playlist(c, s->url, NULL, s->pb)) < 0)
          goto fail;
  
      if ((ret = save_avio_options(s)) < 0)
          goto fail;
  
      /* Some HLS servers don't like being sent the range header */
      av_dict_set(&c->avio_opts, "seekable", "0", 0);
  
      if (c->n_variants == 0) {
          av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
          ret = AVERROR_EOF;
          goto fail;
      }
      /* If the playlist only contained playlists (Master Playlist),
       * parse each individual playlist. */
      if (c->n_playlists > 1 || c->playlists[0]->n_segments == 0) {
          for (i = 0; i < c->n_playlists; i++) {
              struct playlist *pls = c->playlists[i];
              if ((ret = parse_playlist(c, pls->url, pls, NULL)) < 0)
                  goto fail;
          }
      }
  
      if (c->variants[0]->playlists[0]->n_segments == 0) {
          av_log(NULL, AV_LOG_WARNING, "Empty playlist\n");
          ret = AVERROR_EOF;
          goto fail;
      }
  
      /* If this isn't a live stream, calculate the total duration of the
       * stream. */
      if (c->variants[0]->playlists[0]->finished) {
          int64_t duration = 0;
          for (i = 0; i < c->variants[0]->playlists[0]->n_segments; i++)
              duration += c->variants[0]->playlists[0]->segments[i]->duration;
          s->duration = duration;
      }
  
      /* Associate renditions with variants */
      for (i = 0; i < c->n_variants; i++) {
          struct variant *var = c->variants[i];
  
          if (var->audio_group[0])
              add_renditions_to_variant(c, var, AVMEDIA_TYPE_AUDIO, var->audio_group);
          if (var->video_group[0])
              add_renditions_to_variant(c, var, AVMEDIA_TYPE_VIDEO, var->video_group);
          if (var->subtitles_group[0])
              add_renditions_to_variant(c, var, AVMEDIA_TYPE_SUBTITLE, var->subtitles_group);
      }
  
      /* Create a program for each variant */
      for (i = 0; i < c->n_variants; i++) {
          struct variant *v = c->variants[i];
          AVProgram *program;
  
          program = av_new_program(s, i);
          if (!program)
              goto fail;
          av_dict_set_int(&program->metadata, "variant_bitrate", v->bandwidth, 0);
      }
  
      /* Select the starting segments */
      for (i = 0; i < c->n_playlists; i++) {
          struct playlist *pls = c->playlists[i];
  
          if (pls->n_segments == 0)
              continue;
  
          pls->cur_seq_no = select_cur_seq_no(c, pls);
          highest_cur_seq_no = FFMAX(highest_cur_seq_no, pls->cur_seq_no);
      }
  
      /* Open the demuxer for each playlist */
      for (i = 0; i < c->n_playlists; i++) {
          struct playlist *pls = c->playlists[i];
          AVInputFormat *in_fmt = NULL;
  
          if (!(pls->ctx = avformat_alloc_context())) {
              ret = AVERROR(ENOMEM);
              goto fail;
          }
  
          if (pls->n_segments == 0)
              continue;
  
          pls->index  = i;
          pls->needed = 1;
          pls->parent = s;
  
          /*
           * If this is a live stream and this playlist looks like it is one segment
           * behind, try to sync it up so that every substream starts at the same
           * time position (so e.g. avformat_find_stream_info() will see packets from
           * all active streams within the first few seconds). This is not very generic,
           * though, as the sequence numbers are technically independent.
           */
          if (!pls->finished && pls->cur_seq_no == highest_cur_seq_no - 1 &&
              highest_cur_seq_no < pls->start_seq_no + pls->n_segments) {
              pls->cur_seq_no = highest_cur_seq_no;
          }
  
          pls->read_buffer = av_malloc(INITIAL_BUFFER_SIZE);
          if (!pls->read_buffer){
              ret = AVERROR(ENOMEM);
              avformat_free_context(pls->ctx);
              pls->ctx = NULL;
              goto fail;
          }
          ffio_init_context(&pls->pb, pls->read_buffer, INITIAL_BUFFER_SIZE, 0, pls,
                            read_data, NULL, NULL);
          pls->pb.seekable = 0;
          ret = av_probe_input_buffer(&pls->pb, &in_fmt, pls->segments[0]->url,
                                      NULL, 0, 0);
          if (ret < 0) {
              /* Free the ctx - it isn't initialized properly at this point,
               * so avformat_close_input shouldn't be called. If
               * avformat_open_input fails below, it frees and zeros the
               * context, so it doesn't need any special treatment like this. */
              av_log(s, AV_LOG_ERROR, "Error when loading first segment '%s'\n", pls->segments[0]->url);
              avformat_free_context(pls->ctx);
              pls->ctx = NULL;
              goto fail;
          }
          pls->ctx->pb       = &pls->pb;
          pls->ctx->io_open  = nested_io_open;
          pls->ctx->flags   |= s->flags & ~AVFMT_FLAG_CUSTOM_IO;
  
          if ((ret = ff_copy_whiteblacklists(pls->ctx, s)) < 0)
              goto fail;
  
          ret = avformat_open_input(&pls->ctx, pls->segments[0]->url, in_fmt, NULL);
          if (ret < 0)
              goto fail;
  
          if (pls->id3_deferred_extra && pls->ctx->nb_streams == 1) {
              ff_id3v2_parse_apic(pls->ctx, &pls->id3_deferred_extra);
              avformat_queue_attached_pictures(pls->ctx);
              ff_id3v2_parse_priv(pls->ctx, &pls->id3_deferred_extra);
              ff_id3v2_free_extra_meta(&pls->id3_deferred_extra);
              pls->id3_deferred_extra = NULL;
          }
  
          if (pls->is_id3_timestamped == -1)
              av_log(s, AV_LOG_WARNING, "No expected HTTP requests have been made\n");
  
          /*
           * For ID3 timestamped raw audio streams we need to detect the packet
           * durations to calculate timestamps in fill_timing_for_id3_timestamped_stream(),
           * but for other streams we can rely on our user calling avformat_find_stream_info()
           * on us if they want to.
           */
          if (pls->is_id3_timestamped) {
              ret = avformat_find_stream_info(pls->ctx, NULL);
              if (ret < 0)
                  goto fail;
          }
  
          pls->has_noheader_flag = !!(pls->ctx->ctx_flags & AVFMTCTX_NOHEADER);
  
          /* Create new AVStreams for each stream in this playlist */
          ret = update_streams_from_subdemuxer(s, pls);
          if (ret < 0)
              goto fail;
  
          /*
           * Copy any metadata from playlist to main streams, but do not set
           * event flags.
           */
          if (pls->n_main_streams)
              av_dict_copy(&pls->main_streams[0]->metadata, pls->ctx->metadata, 0);
  
          add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_AUDIO);
          add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_VIDEO);
          add_metadata_from_renditions(s, pls, AVMEDIA_TYPE_SUBTITLE);
      }
  
      update_noheader_flag(s);
  
      return 0;
  fail:
      hls_close(s);
      return ret;
  }
  
  static int recheck_discard_flags(AVFormatContext *s, int first)
  {
      HLSContext *c = s->priv_data;
      int i, changed = 0;
      int cur_needed;
  
      /* Check if any new streams are needed */
      for (i = 0; i < c->n_playlists; i++) {
          struct playlist *pls = c->playlists[i];
  
          cur_needed = playlist_needed(c->playlists[i]);
  
          if (cur_needed && !pls->needed) {
              pls->needed = 1;
              changed = 1;
              pls->cur_seq_no = select_cur_seq_no(c, pls);
              pls->pb.eof_reached = 0;
              if (c->cur_timestamp != AV_NOPTS_VALUE) {
                  /* catch up */
                  pls->seek_timestamp = c->cur_timestamp;
                  pls->seek_flags = AVSEEK_FLAG_ANY;
                  pls->seek_stream_index = -1;
              }
              av_log(s, AV_LOG_INFO, "Now receiving playlist %d, segment %d\n", i, pls->cur_seq_no);
          } else if (first && !cur_needed && pls->needed) {
              if (pls->input)
                  ff_format_io_close(pls->parent, &pls->input);
              pls->input_read_done = 0;
              if (pls->input_next)
                  ff_format_io_close(pls->parent, &pls->input_next);
              pls->input_next_requested = 0;
              pls->needed = 0;
              changed = 1;
              av_log(s, AV_LOG_INFO, "No longer receiving playlist %d\n", i);
          }
      }
      return changed;
  }
  
  static void fill_timing_for_id3_timestamped_stream(struct playlist *pls)
  {
      if (pls->id3_offset >= 0) {
          pls->pkt.dts = pls->id3_mpegts_timestamp +
                                   av_rescale_q(pls->id3_offset,
                                                pls->ctx->streams[pls->pkt.stream_index]->time_base,
                                                MPEG_TIME_BASE_Q);
          if (pls->pkt.duration)
              pls->id3_offset += pls->pkt.duration;
          else
              pls->id3_offset = -1;
      } else {
          /* there have been packets with unknown duration
           * since the last id3 tag, should not normally happen */
          pls->pkt.dts = AV_NOPTS_VALUE;
      }
  
      if (pls->pkt.duration)
          pls->pkt.duration = av_rescale_q(pls->pkt.duration,
                                           pls->ctx->streams[pls->pkt.stream_index]->time_base,
                                           MPEG_TIME_BASE_Q);
  
      pls->pkt.pts = AV_NOPTS_VALUE;
  }
  
  static AVRational get_timebase(struct playlist *pls)
  {
      if (pls->is_id3_timestamped)
          return MPEG_TIME_BASE_Q;
  
      return pls->ctx->streams[pls->pkt.stream_index]->time_base;
  }
  
  static int compare_ts_with_wrapdetect(int64_t ts_a, struct playlist *pls_a,
                                        int64_t ts_b, struct playlist *pls_b)
  {
      int64_t scaled_ts_a = av_rescale_q(ts_a, get_timebase(pls_a), MPEG_TIME_BASE_Q);
      int64_t scaled_ts_b = av_rescale_q(ts_b, get_timebase(pls_b), MPEG_TIME_BASE_Q);
  
      return av_compare_mod(scaled_ts_a, scaled_ts_b, 1LL << 33);
  }
  
  static int hls_read_packet(AVFormatContext *s, AVPacket *pkt)
  {
      HLSContext *c = s->priv_data;
      int ret, i, minplaylist = -1;
  
      recheck_discard_flags(s, c->first_packet);
      c->first_packet = 0;
  
      for (i = 0; i < c->n_playlists; i++) {
          struct playlist *pls = c->playlists[i];
          /* Make sure we've got one buffered packet from each open playlist
           * stream */
          if (pls->needed && !pls->pkt.data) {
              while (1) {
                  int64_t ts_diff;
                  AVRational tb;
                  ret = av_read_frame(pls->ctx, &pls->pkt);
                  if (ret < 0) {
                      if (!avio_feof(&pls->pb) && ret != AVERROR_EOF)
                          return ret;
                      reset_packet(&pls->pkt);
                      break;
                  } else {
                      /* stream_index check prevents matching picture attachments etc. */
                      if (pls->is_id3_timestamped && pls->pkt.stream_index == 0) {
                          /* audio elementary streams are id3 timestamped */
                          fill_timing_for_id3_timestamped_stream(pls);
                      }
  
                      if (c->first_timestamp == AV_NOPTS_VALUE &&
                          pls->pkt.dts       != AV_NOPTS_VALUE)
                          c->first_timestamp = av_rescale_q(pls->pkt.dts,
                              get_timebase(pls), AV_TIME_BASE_Q);
                  }
  
                  if (pls->seek_timestamp == AV_NOPTS_VALUE)
                      break;
  
                  if (pls->seek_stream_index < 0 ||
                      pls->seek_stream_index == pls->pkt.stream_index) {
  
                      if (pls->pkt.dts == AV_NOPTS_VALUE) {
                          pls->seek_timestamp = AV_NOPTS_VALUE;
                          break;
                      }
  
                      tb = get_timebase(pls);
                      ts_diff = av_rescale_rnd(pls->pkt.dts, AV_TIME_BASE,
                                              tb.den, AV_ROUND_DOWN) -
                              pls->seek_timestamp;
                      if (ts_diff >= 0 && (pls->seek_flags  & AVSEEK_FLAG_ANY ||
                                          pls->pkt.flags & AV_PKT_FLAG_KEY)) {
                          pls->seek_timestamp = AV_NOPTS_VALUE;
                          break;
                      }
                  }
                  av_packet_unref(&pls->pkt);
                  reset_packet(&pls->pkt);
              }
          }
          /* Check if this stream has the packet with the lowest dts */
          if (pls->pkt.data) {
              struct playlist *minpls = minplaylist < 0 ?
                                       NULL : c->playlists[minplaylist];
              if (minplaylist < 0) {
                  minplaylist = i;
              } else {
                  int64_t dts     =    pls->pkt.dts;
                  int64_t mindts  = minpls->pkt.dts;
  
                  if (dts == AV_NOPTS_VALUE ||
                      (mindts != AV_NOPTS_VALUE && compare_ts_with_wrapdetect(dts, pls, mindts, minpls) < 0))
                      minplaylist = i;
              }
          }
      }
  
      /* If we got a packet, return it */
      if (minplaylist >= 0) {
          struct playlist *pls = c->playlists[minplaylist];
          AVStream *ist;
          AVStream *st;
  
          ret = update_streams_from_subdemuxer(s, pls);
          if (ret < 0) {
              av_packet_unref(&pls->pkt);
              reset_packet(&pls->pkt);
              return ret;
          }
  
          // If sub-demuxer reports updated metadata, copy it to the first stream
          // and set its AVSTREAM_EVENT_FLAG_METADATA_UPDATED flag.
          if (pls->ctx->event_flags & AVFMT_EVENT_FLAG_METADATA_UPDATED) {
              if (pls->n_main_streams) {
                  st = pls->main_streams[0];
                  av_dict_copy(&st->metadata, pls->ctx->metadata, 0);
                  st->event_flags |= AVSTREAM_EVENT_FLAG_METADATA_UPDATED;
              }
              pls->ctx->event_flags &= ~AVFMT_EVENT_FLAG_METADATA_UPDATED;
          }
  
          /* check if noheader flag has been cleared by the subdemuxer */
          if (pls->has_noheader_flag && !(pls->ctx->ctx_flags & AVFMTCTX_NOHEADER)) {
              pls->has_noheader_flag = 0;
              update_noheader_flag(s);
          }
  
          if (pls->pkt.stream_index >= pls->n_main_streams) {
              av_log(s, AV_LOG_ERROR, "stream index inconsistency: index %d, %d main streams, %d subdemuxer streams\n",
                     pls->pkt.stream_index, pls->n_main_streams, pls->ctx->nb_streams);
              av_packet_unref(&pls->pkt);
              reset_packet(&pls->pkt);
              return AVERROR_BUG;
          }
  
          ist = pls->ctx->streams[pls->pkt.stream_index];
          st = pls->main_streams[pls->pkt.stream_index];
  
          *pkt = pls->pkt;
          pkt->stream_index = st->index;
          reset_packet(&c->playlists[minplaylist]->pkt);
  
          if (pkt->dts != AV_NOPTS_VALUE)
              c->cur_timestamp = av_rescale_q(pkt->dts,
                                              ist->time_base,
                                              AV_TIME_BASE_Q);
  
          /* There may be more situations where this would be useful, but this at least
           * handles newly probed codecs properly (i.e. request_probe by mpegts). */
          if (ist->codecpar->codec_id != st->codecpar->codec_id) {
              ret = set_stream_info_from_input_stream(st, pls, ist);
              if (ret < 0) {
                  av_packet_unref(pkt);
                  return ret;
              }
          }
  
          return 0;
      }
      return AVERROR_EOF;
  }
  
  static int hls_read_seek(AVFormatContext *s, int stream_index,
                                 int64_t timestamp, int flags)
  {
      HLSContext *c = s->priv_data;
      struct playlist *seek_pls = NULL;
      int i, seq_no;
      int j;
      int stream_subdemuxer_index;
      int64_t first_timestamp, seek_timestamp, duration;
  
      if ((flags & AVSEEK_FLAG_BYTE) || (c->ctx->ctx_flags & AVFMTCTX_UNSEEKABLE))
          return AVERROR(ENOSYS);
  
      first_timestamp = c->first_timestamp == AV_NOPTS_VALUE ?
                        0 : c->first_timestamp;
  
      seek_timestamp = av_rescale_rnd(timestamp, AV_TIME_BASE,
                                      s->streams[stream_index]->time_base.den,
                                      flags & AVSEEK_FLAG_BACKWARD ?
                                      AV_ROUND_DOWN : AV_ROUND_UP);
  
      duration = s->duration == AV_NOPTS_VALUE ?
                 0 : s->duration;
  
      if (0 < duration && duration < seek_timestamp - first_timestamp)
          return AVERROR(EIO);
  
      /* find the playlist with the specified stream */
      for (i = 0; i < c->n_playlists; i++) {
          struct playlist *pls = c->playlists[i];
          for (j = 0; j < pls->n_main_streams; j++) {
              if (pls->main_streams[j] == s->streams[stream_index]) {
                  seek_pls = pls;
                  stream_subdemuxer_index = j;
                  break;
              }
          }
      }
      /* check if the timestamp is valid for the playlist with the
       * specified stream index */
      if (!seek_pls || !find_timestamp_in_playlist(c, seek_pls, seek_timestamp, &seq_no))
          return AVERROR(EIO);
  
      /* set segment now so we do not need to search again below */
      seek_pls->cur_seq_no = seq_no;
      seek_pls->seek_stream_index = stream_subdemuxer_index;
  
      for (i = 0; i < c->n_playlists; i++) {
          /* Reset reading */
          struct playlist *pls = c->playlists[i];
          if (pls->input)
              ff_format_io_close(pls->parent, &pls->input);
          pls->input_read_done = 0;
          if (pls->input_next)
              ff_format_io_close(pls->parent, &pls->input_next);
          pls->input_next_requested = 0;
          av_packet_unref(&pls->pkt);
          reset_packet(&pls->pkt);
          pls->pb.eof_reached = 0;
          /* Clear any buffered data */
          pls->pb.buf_end = pls->pb.buf_ptr = pls->pb.buffer;
          /* Reset the pos, to let the mpegts demuxer know we've seeked. */
          pls->pb.pos = 0;
          /* Flush the packet queue of the subdemuxer. */
          ff_read_frame_flush(pls->ctx);
  
          pls->seek_timestamp = seek_timestamp;
          pls->seek_flags = flags;
  
          if (pls != seek_pls) {
              /* set closest segment seq_no for playlists not handled above */
              find_timestamp_in_playlist(c, pls, seek_timestamp, &pls->cur_seq_no);
              /* seek the playlist to the given position without taking
               * keyframes into account since this playlist does not have the
               * specified stream where we should look for the keyframes */
              pls->seek_stream_index = -1;
              pls->seek_flags |= AVSEEK_FLAG_ANY;
          }
      }
  
      c->cur_timestamp = seek_timestamp;
  
      return 0;
  }
  
  static int hls_probe(AVProbeData *p)
  {
      /* Require #EXTM3U at the start, and either one of the ones below
       * somewhere for a proper match. */
      if (strncmp(p->buf, "#EXTM3U", 7))
          return 0;
  
      if (strstr(p->buf, "#EXT-X-STREAM-INF:")     ||
          strstr(p->buf, "#EXT-X-TARGETDURATION:") ||
          strstr(p->buf, "#EXT-X-MEDIA-SEQUENCE:"))
          return AVPROBE_SCORE_MAX;
      return 0;
  }
  
  #define OFFSET(x) offsetof(HLSContext, x)
  #define FLAGS AV_OPT_FLAG_DECODING_PARAM
  static const AVOption hls_options[] = {
      {"live_start_index", "segment index to start live streams at (negative values are from the end)",
          OFFSET(live_start_index), AV_OPT_TYPE_INT, {.i64 = -3}, INT_MIN, INT_MAX, FLAGS},
      {"allowed_extensions", "List of file extensions that hls is allowed to access",
          OFFSET(allowed_extensions), AV_OPT_TYPE_STRING,
          {.str = "ALL"},
          INT_MIN, INT_MAX, FLAGS},
      {"max_reload", "Maximum number of times a insufficient list is attempted to be reloaded",
          OFFSET(max_reload), AV_OPT_TYPE_INT, {.i64 = 1000}, 0, INT_MAX, FLAGS},
      {"http_persistent", "Use persistent HTTP connections",
          OFFSET(http_persistent), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, FLAGS },
      {"http_multiple", "Use multiple HTTP connections for fetching segments",
          OFFSET(http_multiple), AV_OPT_TYPE_BOOL, {.i64 = -1}, -1, 1, FLAGS},
      {NULL}
  };
  
  static const AVClass hls_class = {
      .class_name = "hls,applehttp",
      .item_name  = av_default_item_name,
      .option     = hls_options,
      .version    = LIBAVUTIL_VERSION_INT,
  };
  
  AVInputFormat ff_hls_demuxer = {
      .name           = "hls,applehttp",
      .long_name      = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
      .priv_class     = &hls_class,
      .priv_data_size = sizeof(HLSContext),
      .flags          = AVFMT_NOGENSEARCH,
      .read_probe     = hls_probe,
      .read_header    = hls_read_header,
      .read_packet    = hls_read_packet,
      .read_close     = hls_close,
      .read_seek      = hls_read_seek,
  };
  