/*
  * Apple HTTP Live Streaming segmenter
  * Copyright (c) 2012, Luca Barbato
  *

  * 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
  */
 

 #include "config.h"

 #include <float.h>

 #include <stdint.h>

 #if HAVE_UNISTD_H
 #include <unistd.h>
 #endif

 #if CONFIG_GCRYPT
 #include <gcrypt.h>
 #elif CONFIG_OPENSSL
 #include <openssl/rand.h>
 #endif
 

 #include "libavutil/avassert.h"

 #include "libavutil/mathematics.h"
 #include "libavutil/parseutils.h"
 #include "libavutil/avstring.h"

 #include "libavutil/intreadwrite.h"
 #include "libavutil/random_seed.h"

 #include "libavutil/opt.h"
 #include "libavutil/log.h"

 #include "libavutil/time_internal.h"

 
 #include "avformat.h"

 #include "avio_internal.h"

 #include "internal.h"

 #include "os_support.h"

 typedef enum {
   HLS_START_SEQUENCE_AS_START_NUMBER = 0,
   HLS_START_SEQUENCE_AS_SECONDS_SINCE_EPOCH = 1,
   HLS_START_SEQUENCE_AS_FORMATTED_DATETIME = 2,  // YYYYMMDDhhmmss
 } StartSequenceSourceType;
 

 #define KEYSIZE 16
 #define LINE_BUFFER_SIZE 1024

 #define HLS_MICROSECOND_UNIT   1000000

 typedef struct HLSSegment {
     char filename[1024];

     char sub_filename[1024];

     double duration; /* in seconds */

     int discont;

     int64_t pos;
     int64_t size;

     char key_uri[LINE_BUFFER_SIZE + 1];
     char iv_string[KEYSIZE*2 + 1];
 

     struct HLSSegment *next;
 } HLSSegment;

 typedef enum HLSFlags {
     // Generate a single media file and use byte ranges in the playlist.
     HLS_SINGLE_FILE = (1 << 0),

     HLS_DELETE_SEGMENTS = (1 << 1),

     HLS_ROUND_DURATIONS = (1 << 2),

     HLS_DISCONT_START = (1 << 3),

     HLS_OMIT_ENDLIST = (1 << 4),

     HLS_SPLIT_BY_TIME = (1 << 5),

     HLS_APPEND_LIST = (1 << 6),

     HLS_PROGRAM_DATE_TIME = (1 << 7),

     HLS_SECOND_LEVEL_SEGMENT_INDEX = (1 << 8), // include segment index in segment filenames when use_localtime  e.g.: %%03d

     HLS_SECOND_LEVEL_SEGMENT_DURATION = (1 << 9), // include segment duration (microsec) in segment filenames when use_localtime  e.g.: %%09t
     HLS_SECOND_LEVEL_SEGMENT_SIZE = (1 << 10), // include segment size (bytes) in segment filenames when use_localtime  e.g.: %%014s

     HLS_TEMP_FILE = (1 << 11),

     HLS_PERIODIC_REKEY = (1 << 12),

 } HLSFlags;
 

 typedef enum {

     SEGMENT_TYPE_MPEGTS,
     SEGMENT_TYPE_FMP4,
 } SegmentType;
 
 typedef enum {

     PLAYLIST_TYPE_NONE,
     PLAYLIST_TYPE_EVENT,
     PLAYLIST_TYPE_VOD,
     PLAYLIST_TYPE_NB,
 } PlaylistType;
 

 typedef struct HLSContext {
     const AVClass *class;  // Class for private options.

     unsigned number;

     int64_t sequence;

     int64_t start_sequence;

     uint32_t start_sequence_source_type;  // enum StartSequenceSourceType

     AVOutputFormat *oformat;

     AVOutputFormat *vtt_oformat;

     AVIOContext *out;
     int packets_written;
     int init_range_length;

     AVFormatContext *avf;

     AVFormatContext *vtt_avf;

     float time;            // Set by a private option.

     float init_time;       // Set by a private option.

     int max_nb_segments;   // Set by a private option.

 #if FF_API_HLS_WRAP

     int  wrap;             // Set by a private option.

 #endif

     uint32_t flags;        // enum HLSFlags

     uint32_t pl_type;      // enum PlaylistType

     char *segment_filename;

     char *fmp4_init_filename;
     int segment_type;
     int fmp4_init_mode;

     int use_localtime;      ///< flag to expand filename with localtime

     int use_localtime_mkdir;///< flag to mkdir dirname in timebased filename

     int allowcache;

     int64_t recording_time;
     int has_video;

     int has_subtitle;

     int new_start;
     double dpp;           // duration per packet

     int64_t start_pts;
     int64_t end_pts;

     double duration;      // last segment duration computed so far, in seconds

     int64_t start_pos;    // last segment starting position
     int64_t size;         // last segment size

     int64_t max_seg_size; // every segment file max size

     int nb_entries;

     int discontinuity_set;

     int discontinuity;

     HLSSegment *segments;
     HLSSegment *last_segment;

     HLSSegment *old_segments;

     char *basename;

     char *base_output_dirname;

     char *vtt_basename;
     char *vtt_m3u8_name;

     char *baseurl;

     char *format_options_str;

     char *vtt_format_options_str;
     char *subtitle_filename;

     AVDictionary *format_options;

     int encrypt;
     char *key;
     char *key_url;
     char *iv;
     char *key_basename;
 

     char *key_info_file;
     char key_file[LINE_BUFFER_SIZE + 1];
     char key_uri[LINE_BUFFER_SIZE + 1];
     char key_string[KEYSIZE*2 + 1];
     char iv_string[KEYSIZE*2 + 1];

     AVDictionary *vtt_format_options;
 

     char *method;
 

     double initial_prog_date_time;

     char current_segment_final_filename_fmt[1024]; // when renaming segments

     char *user_agent;

 } HLSContext;
 

 static int get_int_from_double(double val)
 {
     return (int)((val - (int)val) >= 0.001) ? (int)(val + 1) : (int)val;
 }
 

 static int mkdir_p(const char *path) {
     int ret = 0;
     char *temp = av_strdup(path);
     char *pos = temp;
     char tmp_ch = '\0';
 
     if (!path || !temp) {
         return -1;
     }
 
     if (!strncmp(temp, "/", 1) || !strncmp(temp, "\\", 1)) {
         pos++;
     } else if (!strncmp(temp, "./", 2) || !strncmp(temp, ".\\", 2)) {
         pos += 2;
     }
 
     for ( ; *pos != '\0'; ++pos) {
         if (*pos == '/' || *pos == '\\') {
             tmp_ch = *pos;
             *pos = '\0';
             ret = mkdir(temp, 0755);
             *pos = tmp_ch;
         }
     }
 
     if ((*(pos - 1) != '/') || (*(pos - 1) != '\\')) {
         ret = mkdir(temp, 0755);
     }
 
     av_free(temp);
     return ret;
 }
 

 static void set_http_options(AVFormatContext *s, AVDictionary **options, HLSContext *c)
 {
     const char *proto = avio_find_protocol_name(s->filename);
     int http_base_proto = proto ? (!av_strcasecmp(proto, "http") || !av_strcasecmp(proto, "https")) : 0;
 
     if (c->method) {
         av_dict_set(options, "method", c->method, 0);
     } else if (http_base_proto) {
         av_log(c, AV_LOG_WARNING, "No HTTP method set, hls muxer defaulting to method PUT.\n");
         av_dict_set(options, "method", "PUT", 0);
     }
     if (c->user_agent)
         av_dict_set(options, "user_agent", c->user_agent, 0);
 
 }
 

 static int replace_int_data_in_filename(char *buf, int buf_size, const char *filename, char placeholder, int64_t number)
 {
     const char *p;
     char *q, buf1[20], c;
     int nd, len, addchar_count;
     int found_count = 0;
 
     q = buf;
     p = filename;
     for (;;) {
         c = *p;
         if (c == '\0')
             break;
         if (c == '%' && *(p+1) == '%')  // %%
             addchar_count = 2;
         else if (c == '%' && (av_isdigit(*(p+1)) || *(p+1) == placeholder)) {
             nd = 0;
             addchar_count = 1;
             while (av_isdigit(*(p + addchar_count))) {
                 nd = nd * 10 + *(p + addchar_count) - '0';
                 addchar_count++;
             }
 
             if (*(p + addchar_count) == placeholder) {
                 len = snprintf(buf1, sizeof(buf1), "%0*"PRId64, (number < 0) ? nd : nd++, number);
                 if (len < 1)  // returned error or empty buf1
                     goto fail;
                 if ((q - buf + len) > buf_size - 1)
                     goto fail;
                 memcpy(q, buf1, len);
                 q += len;
                 p += (addchar_count + 1);
                 addchar_count = 0;
                 found_count++;
             }
 
         } else
             addchar_count = 1;
 
         while (addchar_count--)
             if ((q - buf) < buf_size - 1)
                 *q++ = *p++;
             else
                 goto fail;
     }
     *q = '\0';
     return found_count;
 fail:
     *q = '\0';
     return -1;
 }
 

 static void write_styp(AVIOContext *pb)
 {
     avio_wb32(pb, 24);
     ffio_wfourcc(pb, "styp");
     ffio_wfourcc(pb, "msdh");
     avio_wb32(pb, 0); /* minor */
     ffio_wfourcc(pb, "msdh");
     ffio_wfourcc(pb, "msix");
 }
 

 static int hls_delete_old_segments(AVFormatContext *s, HLSContext *hls) {

 
     HLSSegment *segment, *previous_segment = NULL;
     float playlist_duration = 0.0f;

     int ret = 0, path_size, sub_path_size;

     char *dirname = NULL, *p, *sub_path;
     char *path = NULL;

     AVDictionary *options = NULL;
     AVIOContext *out = NULL;

     const char *proto = NULL;

 
     segment = hls->segments;
     while (segment) {
         playlist_duration += segment->duration;
         segment = segment->next;
     }
 
     segment = hls->old_segments;
     while (segment) {
         playlist_duration -= segment->duration;
         previous_segment = segment;
         segment = previous_segment->next;
         if (playlist_duration <= -previous_segment->duration) {
             previous_segment->next = NULL;
             break;
         }
     }
 

     if (segment && !hls->use_localtime_mkdir) {

         if (hls->segment_filename) {
             dirname = av_strdup(hls->segment_filename);
         } else {
             dirname = av_strdup(hls->avf->filename);
         }
         if (!dirname) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }
         p = (char *)av_basename(dirname);
         *p = '\0';
     }
 
     while (segment) {
         av_log(hls, AV_LOG_DEBUG, "deleting old segment %s\n",
                                   segment->filename);

         path_size =  (hls->use_localtime_mkdir ? 0 : strlen(dirname)) + strlen(segment->filename) + 1;

         path = av_malloc(path_size);
         if (!path) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }

         if (hls->use_localtime_mkdir)
             av_strlcpy(path, segment->filename, path_size);
         else { // segment->filename contains basename only
             av_strlcpy(path, dirname, path_size);
             av_strlcat(path, segment->filename, path_size);
         }
 

         proto = avio_find_protocol_name(s->filename);
         if (hls->method || (proto && !av_strcasecmp(proto, "http"))) {

             av_dict_set(&options, "method", "DELETE", 0);
             if ((ret = hls->avf->io_open(hls->avf, &out, path, AVIO_FLAG_WRITE, &options)) < 0)
                 goto fail;

             ff_format_io_close(hls->avf, &out);

         } else if (unlink(path) < 0) {

             av_log(hls, AV_LOG_ERROR, "failed to delete old segment %s: %s\n",
                                      path, strerror(errno));
         }

         if ((segment->sub_filename[0] != '\0')) {
             sub_path_size = strlen(segment->sub_filename) + 1 + (dirname ? strlen(dirname) : 0);

             sub_path = av_malloc(sub_path_size);
             if (!sub_path) {
                 ret = AVERROR(ENOMEM);
                 goto fail;
             }
 
             av_strlcpy(sub_path, dirname, sub_path_size);
             av_strlcat(sub_path, segment->sub_filename, sub_path_size);

             if (hls->method || (proto && !av_strcasecmp(proto, "http"))) {

                 av_dict_set(&options, "method", "DELETE", 0);
                 if ((ret = hls->avf->io_open(hls->avf, &out, sub_path, AVIO_FLAG_WRITE, &options)) < 0) {
                     av_free(sub_path);
                     goto fail;
                 }

                 ff_format_io_close(hls->avf, &out);

             } else if (unlink(sub_path) < 0) {

                 av_log(hls, AV_LOG_ERROR, "failed to delete old segment %s: %s\n",
                                          sub_path, strerror(errno));
             }
             av_free(sub_path);

         }

         av_freep(&path);

         previous_segment = segment;
         segment = previous_segment->next;
         av_free(previous_segment);
     }
 
 fail:

     av_free(path);

     av_free(dirname);
 
     return ret;
 }
 

 static int randomize(uint8_t *buf, int len)
 {
 #if CONFIG_GCRYPT
     gcry_randomize(buf, len, GCRY_VERY_STRONG_RANDOM);
     return 0;
 #elif CONFIG_OPENSSL
     if (RAND_bytes(buf, len))
         return 0;
 #else
     return AVERROR(ENOSYS);
 #endif
     return AVERROR(EINVAL);
 }
 
 static int do_encrypt(AVFormatContext *s)
 {
     HLSContext *hls = s->priv_data;
     int ret;
     int len;
     AVIOContext *pb;
     uint8_t key[KEYSIZE];
 
     len = strlen(hls->basename) + 4 + 1;
     hls->key_basename = av_mallocz(len);
     if (!hls->key_basename)
         return AVERROR(ENOMEM);
 
     av_strlcpy(hls->key_basename, s->filename, len);
     av_strlcat(hls->key_basename, ".key", len);
 
     if (hls->key_url) {

         av_strlcpy(hls->key_file, hls->key_url, sizeof(hls->key_file));
         av_strlcpy(hls->key_uri, hls->key_url, sizeof(hls->key_uri));

     } else {

         av_strlcpy(hls->key_file, hls->key_basename, sizeof(hls->key_file));
         av_strlcpy(hls->key_uri, hls->key_basename, sizeof(hls->key_uri));

     }
 
     if (!*hls->iv_string) {
         uint8_t iv[16] = { 0 };
         char buf[33];
 
         if (!hls->iv) {
             AV_WB64(iv + 8, hls->sequence);
         } else {
             memcpy(iv, hls->iv, sizeof(iv));
         }
         ff_data_to_hex(buf, iv, sizeof(iv), 0);
         buf[32] = '\0';
         memcpy(hls->iv_string, buf, sizeof(hls->iv_string));
     }
 
     if (!*hls->key_uri) {
         av_log(hls, AV_LOG_ERROR, "no key URI specified in key info file\n");
         return AVERROR(EINVAL);
     }
 
     if (!*hls->key_file) {
         av_log(hls, AV_LOG_ERROR, "no key file specified in key info file\n");
         return AVERROR(EINVAL);
     }
 
     if (!*hls->key_string) {
         if (!hls->key) {
             if ((ret = randomize(key, sizeof(key))) < 0) {
                 av_log(s, AV_LOG_ERROR, "Cannot generate a strong random key\n");
                 return ret;
             }
         } else {
             memcpy(key, hls->key, sizeof(key));
         }
 
         ff_data_to_hex(hls->key_string, key, sizeof(key), 0);
         if ((ret = s->io_open(s, &pb, hls->key_file, AVIO_FLAG_WRITE, NULL)) < 0)
             return ret;
         avio_seek(pb, 0, SEEK_CUR);
         avio_write(pb, key, KEYSIZE);
         avio_close(pb);
     }
     return 0;
 }
 
 

 static int hls_encryption_start(AVFormatContext *s)
 {
     HLSContext *hls = s->priv_data;
     int ret;
     AVIOContext *pb;
     uint8_t key[KEYSIZE];
 

     if ((ret = s->io_open(s, &pb, hls->key_info_file, AVIO_FLAG_READ, NULL)) < 0) {

         av_log(hls, AV_LOG_ERROR,
                 "error opening key info file %s\n", hls->key_info_file);
         return ret;
     }
 
     ff_get_line(pb, hls->key_uri, sizeof(hls->key_uri));
     hls->key_uri[strcspn(hls->key_uri, "\r\n")] = '\0';
 
     ff_get_line(pb, hls->key_file, sizeof(hls->key_file));
     hls->key_file[strcspn(hls->key_file, "\r\n")] = '\0';
 
     ff_get_line(pb, hls->iv_string, sizeof(hls->iv_string));
     hls->iv_string[strcspn(hls->iv_string, "\r\n")] = '\0';
 

     ff_format_io_close(s, &pb);

 
     if (!*hls->key_uri) {
         av_log(hls, AV_LOG_ERROR, "no key URI specified in key info file\n");
         return AVERROR(EINVAL);
     }
 
     if (!*hls->key_file) {
         av_log(hls, AV_LOG_ERROR, "no key file specified in key info file\n");
         return AVERROR(EINVAL);
     }
 

     if ((ret = s->io_open(s, &pb, hls->key_file, AVIO_FLAG_READ, NULL)) < 0) {

         av_log(hls, AV_LOG_ERROR, "error opening key file %s\n", hls->key_file);
         return ret;
     }
 
     ret = avio_read(pb, key, sizeof(key));

     ff_format_io_close(s, &pb);

     if (ret != sizeof(key)) {
         av_log(hls, AV_LOG_ERROR, "error reading key file %s\n", hls->key_file);
         if (ret >= 0 || ret == AVERROR_EOF)
             ret = AVERROR(EINVAL);
         return ret;
     }
     ff_data_to_hex(hls->key_string, key, sizeof(key), 0);
 
     return 0;
 }
 

 static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
 {
     int len = ff_get_line(s, buf, maxlen);
     while (len > 0 && av_isspace(buf[len - 1]))
         buf[--len] = '\0';
     return len;
 }
 

 static int hls_mux_init(AVFormatContext *s)
 {

     AVDictionary *options = NULL;

     HLSContext *hls = s->priv_data;
     AVFormatContext *oc;

     AVFormatContext *vtt_oc = NULL;

     int byterange_mode = (hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size > 0);

     int i, ret;

     ret = avformat_alloc_output_context2(&hls->avf, hls->oformat, NULL, NULL);
     if (ret < 0)
         return ret;
     oc = hls->avf;

     oc->filename[0]        = '\0';

     oc->oformat            = hls->oformat;
     oc->interrupt_callback = s->interrupt_callback;

     oc->max_delay          = s->max_delay;

     oc->opaque             = s->opaque;
     oc->io_open            = s->io_open;
     oc->io_close           = s->io_close;

     av_dict_copy(&oc->metadata, s->metadata, 0);

     if(hls->vtt_oformat) {
         ret = avformat_alloc_output_context2(&hls->vtt_avf, hls->vtt_oformat, NULL, NULL);
         if (ret < 0)
             return ret;
         vtt_oc          = hls->vtt_avf;
         vtt_oc->oformat = hls->vtt_oformat;
         av_dict_copy(&vtt_oc->metadata, s->metadata, 0);
     }
 

     for (i = 0; i < s->nb_streams; i++) {
         AVStream *st;

         AVFormatContext *loc;

         if (s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE)

             loc = vtt_oc;
         else
             loc = oc;
 
         if (!(st = avformat_new_stream(loc, NULL)))

             return AVERROR(ENOMEM);

         avcodec_parameters_copy(st->codecpar, s->streams[i]->codecpar);

         if (!oc->oformat->codec_tag ||
             av_codec_get_id (oc->oformat->codec_tag, s->streams[i]->codecpar->codec_tag) == st->codecpar->codec_id ||
             av_codec_get_tag(oc->oformat->codec_tag, s->streams[i]->codecpar->codec_id) <= 0) {
             st->codecpar->codec_tag = s->streams[i]->codecpar->codec_tag;
         } else {
             st->codecpar->codec_tag = 0;
         }
 

         st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;

         st->time_base = s->streams[i]->time_base;

         av_dict_copy(&st->metadata, s->streams[i]->metadata, 0);

     }

     hls->packets_written = 1;

     hls->start_pos = 0;

     hls->new_start = 1;

     hls->fmp4_init_mode = 0;

     if (hls->segment_type == SEGMENT_TYPE_FMP4) {

         if (hls->max_seg_size > 0) {
             av_log(s, AV_LOG_WARNING, "Multi-file byterange mode is currently unsupported in the HLS muxer.\n");
             return AVERROR_PATCHWELCOME;
         }

         hls->packets_written = 0;
         hls->init_range_length = 0;

         hls->fmp4_init_mode = !byterange_mode;

         set_http_options(s, &options, hls);

         if ((ret = avio_open_dyn_buf(&oc->pb)) < 0)
             return ret;
 
         if ((ret = s->io_open(s, &hls->out, hls->base_output_dirname, AVIO_FLAG_WRITE, &options)) < 0) {

             av_log(s, AV_LOG_ERROR, "Failed to open segment '%s'\n", hls->fmp4_init_filename);
             return ret;
         }
 
         if (hls->format_options_str) {
             ret = av_dict_parse_string(&hls->format_options, hls->format_options_str, "=", ":", 0);
             if (ret < 0) {
                 av_log(s, AV_LOG_ERROR, "Could not parse format options list '%s'\n",
                        hls->format_options_str);
                 return ret;
             }
         }
 
         av_dict_copy(&options, hls->format_options, 0);
         av_dict_set(&options, "fflags", "-autobsf", 0);
         av_dict_set(&options, "movflags", "frag_custom+dash+delay_moov", 0);
         ret = avformat_init_output(oc, &options);

         if (ret < 0)
             return ret;

         if (av_dict_count(options)) {
             av_log(s, AV_LOG_ERROR, "Some of the provided format options in '%s' are not recognized\n", hls->format_options_str);
             av_dict_free(&options);
             return AVERROR(EINVAL);
         }

         avio_flush(oc->pb);

         av_dict_free(&options);
     }

     return 0;
 }
 

 static HLSSegment *find_segment_by_filename(HLSSegment *segment, const char *filename)
 {
     while (segment) {
         if (!av_strcasecmp(segment->filename,filename))
             return segment;
         segment = segment->next;
     }
     return (HLSSegment *) NULL;
 }
 

 static int sls_flags_filename_process(struct AVFormatContext *s, HLSContext *hls, HLSSegment *en, double duration,
                                          int64_t pos, int64_t size)

 {

     if ((hls->flags & (HLS_SECOND_LEVEL_SEGMENT_SIZE | HLS_SECOND_LEVEL_SEGMENT_DURATION)) &&
         strlen(hls->current_segment_final_filename_fmt)) {
         av_strlcpy(hls->avf->filename, hls->current_segment_final_filename_fmt, sizeof(hls->avf->filename));
         if (hls->flags & HLS_SECOND_LEVEL_SEGMENT_SIZE) {
             char * filename = av_strdup(hls->avf->filename);  // %%s will be %s after strftime

             if (!filename) {
                 av_free(en);

                 return AVERROR(ENOMEM);

             }

             if (replace_int_data_in_filename(hls->avf->filename, sizeof(hls->avf->filename),
                 filename, 's', pos + size) < 1) {
                 av_log(hls, AV_LOG_ERROR,
                        "Invalid second level segment filename template '%s', "
                         "you can try to remove second_level_segment_size flag\n",
                        filename);
                 av_free(filename);

                 av_free(en);

                 return AVERROR(EINVAL);
             }
             av_free(filename);
         }
         if (hls->flags & HLS_SECOND_LEVEL_SEGMENT_DURATION) {
             char * filename = av_strdup(hls->avf->filename);  // %%t will be %t after strftime

             if (!filename) {
                 av_free(en);

                 return AVERROR(ENOMEM);

             }

             if (replace_int_data_in_filename(hls->avf->filename, sizeof(hls->avf->filename),

                 filename, 't',  (int64_t)round(duration * HLS_MICROSECOND_UNIT)) < 1) {

                 av_log(hls, AV_LOG_ERROR,
                        "Invalid second level segment filename template '%s', "
                         "you can try to remove second_level_segment_time flag\n",
                        filename);
                 av_free(filename);

                 av_free(en);

                 return AVERROR(EINVAL);
             }
             av_free(filename);
         }
     }

     return 0;
 }
 
 static int sls_flag_check_duration_size_index(HLSContext *hls)
 {
     int ret = 0;
 
     if (hls->flags & HLS_SECOND_LEVEL_SEGMENT_DURATION) {
          av_log(hls, AV_LOG_ERROR,
                 "second_level_segment_duration hls_flag requires use_localtime to be true\n");
          ret = AVERROR(EINVAL);
     }
     if (hls->flags & HLS_SECOND_LEVEL_SEGMENT_SIZE) {
          av_log(hls, AV_LOG_ERROR,
                 "second_level_segment_size hls_flag requires use_localtime to be true\n");
          ret = AVERROR(EINVAL);
     }
     if (hls->flags & HLS_SECOND_LEVEL_SEGMENT_INDEX) {
         av_log(hls, AV_LOG_ERROR,
                "second_level_segment_index hls_flag requires use_localtime to be true\n");
         ret = AVERROR(EINVAL);
     }
 
     return ret;
 }
 
 static int sls_flag_check_duration_size(HLSContext *hls)
 {
     const char *proto = avio_find_protocol_name(hls->basename);
     int segment_renaming_ok = proto && !strcmp(proto, "file");
     int ret = 0;
 
     if ((hls->flags & HLS_SECOND_LEVEL_SEGMENT_DURATION) && !segment_renaming_ok) {
          av_log(hls, AV_LOG_ERROR,
                 "second_level_segment_duration hls_flag works only with file protocol segment names\n");
          ret = AVERROR(EINVAL);
     }
     if ((hls->flags & HLS_SECOND_LEVEL_SEGMENT_SIZE) && !segment_renaming_ok) {
          av_log(hls, AV_LOG_ERROR,
                 "second_level_segment_size hls_flag works only with file protocol segment names\n");
          ret = AVERROR(EINVAL);
     }
 
     return ret;
 }
 
 static void sls_flag_file_rename(HLSContext *hls, char *old_filename) {
     if ((hls->flags & (HLS_SECOND_LEVEL_SEGMENT_SIZE | HLS_SECOND_LEVEL_SEGMENT_DURATION)) &&
         strlen(hls->current_segment_final_filename_fmt)) {
         ff_rename(old_filename, hls->avf->filename, hls);
     }
 }
 
 static int sls_flag_use_localtime_filename(AVFormatContext *oc, HLSContext *c)
 {
     if (c->flags & HLS_SECOND_LEVEL_SEGMENT_INDEX) {
         char * filename = av_strdup(oc->filename);  // %%d will be %d after strftime
         if (!filename)
             return AVERROR(ENOMEM);
         if (replace_int_data_in_filename(oc->filename, sizeof(oc->filename),
 #if FF_API_HLS_WRAP
             filename, 'd', c->wrap ? c->sequence % c->wrap : c->sequence) < 1) {
 #else
             filename, 'd', c->sequence) < 1) {
 #endif
             av_log(c, AV_LOG_ERROR, "Invalid second level segment filename template '%s', "
                     "you can try to remove second_level_segment_index flag\n",
                    filename);
             av_free(filename);
             return AVERROR(EINVAL);
         }
         av_free(filename);
     }
     if (c->flags & (HLS_SECOND_LEVEL_SEGMENT_SIZE | HLS_SECOND_LEVEL_SEGMENT_DURATION)) {
         av_strlcpy(c->current_segment_final_filename_fmt, oc->filename,
                    sizeof(c->current_segment_final_filename_fmt));
         if (c->flags & HLS_SECOND_LEVEL_SEGMENT_SIZE) {
             char * filename = av_strdup(oc->filename);  // %%s will be %s after strftime
             if (!filename)
                 return AVERROR(ENOMEM);
             if (replace_int_data_in_filename(oc->filename, sizeof(oc->filename), filename, 's', 0) < 1) {
                 av_log(c, AV_LOG_ERROR, "Invalid second level segment filename template '%s', "
                         "you can try to remove second_level_segment_size flag\n",
                        filename);
                 av_free(filename);
                 return AVERROR(EINVAL);
             }
             av_free(filename);
         }
         if (c->flags & HLS_SECOND_LEVEL_SEGMENT_DURATION) {
             char * filename = av_strdup(oc->filename);  // %%t will be %t after strftime
             if (!filename)
                 return AVERROR(ENOMEM);
             if (replace_int_data_in_filename(oc->filename, sizeof(oc->filename), filename, 't', 0) < 1) {
                 av_log(c, AV_LOG_ERROR, "Invalid second level segment filename template '%s', "
                         "you can try to remove second_level_segment_time flag\n",
                        filename);
                 av_free(filename);
                 return AVERROR(EINVAL);
             }
             av_free(filename);
         }
     }
     return 0;
 }
 
 /* Create a new segment and append it to the segment list */
 static int hls_append_segment(struct AVFormatContext *s, HLSContext *hls, double duration,
                               int64_t pos, int64_t size)
 {
     HLSSegment *en = av_malloc(sizeof(*en));
     const char  *filename;

     int byterange_mode = (hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size > 0);

     int ret;

     if (!en)
         return AVERROR(ENOMEM);
 
     ret = sls_flags_filename_process(s, hls, en, duration, pos, size);
     if (ret < 0) {
         return ret;
     }

     filename = av_basename(hls->avf->filename);
 
     if (hls->use_localtime_mkdir) {

         filename = hls->avf->filename;

     }

     if ((find_segment_by_filename(hls->segments, filename) || find_segment_by_filename(hls->old_segments, filename))
         && !byterange_mode) {

         av_log(hls, AV_LOG_WARNING, "Duplicated segment filename detected: %s\n", filename);
     }

     av_strlcpy(en->filename, filename, sizeof(en->filename));

     if(hls->has_subtitle)
         av_strlcpy(en->sub_filename, av_basename(hls->vtt_avf->filename), sizeof(en->sub_filename));

     else
         en->sub_filename[0] = '\0';

     en->duration = duration;

     en->pos      = pos;
     en->size     = size;

     en->next     = NULL;

     en->discont  = 0;
 
     if (hls->discontinuity) {
         en->discont = 1;
         hls->discontinuity = 0;
     }

     if (hls->key_info_file || hls->encrypt) {

         av_strlcpy(en->key_uri, hls->key_uri, sizeof(en->key_uri));
         av_strlcpy(en->iv_string, hls->iv_string, sizeof(en->iv_string));
     }
 

     if (!hls->segments)
         hls->segments = en;

     else

         hls->last_segment->next = en;

     hls->last_segment = en;

     // EVENT or VOD playlists imply sliding window cannot be used
     if (hls->pl_type != PLAYLIST_TYPE_NONE)
         hls->max_nb_segments = 0;
 

     if (hls->max_nb_segments && hls->nb_entries >= hls->max_nb_segments) {
         en = hls->segments;

         hls->initial_prog_date_time += en->duration;

         hls->segments = en->next;

         if (en && hls->flags & HLS_DELETE_SEGMENTS &&

 #if FF_API_HLS_WRAP

                 !(hls->flags & HLS_SINGLE_FILE || hls->wrap)) {

 #else
                 !(hls->flags & HLS_SINGLE_FILE)) {
 #endif

             en->next = hls->old_segments;
             hls->old_segments = en;

             if ((ret = hls_delete_old_segments(s, hls)) < 0)

                 return ret;
         } else
             av_free(en);

     } else
         hls->nb_entries++;

     if (hls->max_seg_size > 0) {
         return 0;
     }

     hls->sequence++;
 

     return 0;
 }
 

 static int parse_playlist(AVFormatContext *s, const char *url)
 {
     HLSContext *hls = s->priv_data;
     AVIOContext *in;
     int ret = 0, is_segment = 0;
     int64_t new_start_pos;
     char line[1024];
     const char *ptr;

     const char *end;

 
     if ((ret = ffio_open_whitelist(&in, url, AVIO_FLAG_READ,
                                    &s->interrupt_callback, NULL,
                                    s->protocol_whitelist, s->protocol_blacklist)) < 0)
         return ret;
 
     read_chomp_line(in, line, sizeof(line));
     if (strcmp(line, "#EXTM3U")) {
         ret = AVERROR_INVALIDDATA;
         goto fail;
     }
 

     hls->discontinuity = 0;

     while (!avio_feof(in)) {
         read_chomp_line(in, line, sizeof(line));
         if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {

             int64_t tmp_sequence = strtoll(ptr, NULL, 10);
             if (tmp_sequence < hls->sequence)
               av_log(hls, AV_LOG_VERBOSE,
                      "Found playlist sequence number was smaller """
                      "than specified start sequence number: %"PRId64" < %"PRId64", "
                      "omitting\n", tmp_sequence, hls->start_sequence);
             else {
               av_log(hls, AV_LOG_DEBUG, "Found playlist sequence number: %"PRId64"\n", tmp_sequence);
               hls->sequence = tmp_sequence;
             }

         } else if (av_strstart(line, "#EXT-X-DISCONTINUITY", &ptr)) {
             is_segment = 1;
             hls->discontinuity = 1;

         } else if (av_strstart(line, "#EXTINF:", &ptr)) {
             is_segment = 1;
             hls->duration = atof(ptr);

         } else if (av_stristart(line, "#EXT-X-KEY:", &ptr)) {
             ptr = av_stristr(line, "URI=\"");
             if (ptr) {
                 ptr += strlen("URI=\"");
                 end = av_stristr(ptr, ",");
                 if (end) {
                     av_strlcpy(hls->key_uri, ptr, end - ptr);
                 } else {
                     av_strlcpy(hls->key_uri, ptr, sizeof(hls->key_uri));
                 }
             }
 
             ptr = av_stristr(line, "IV=0x");
             if (ptr) {
                 ptr += strlen("IV=0x");
                 end = av_stristr(ptr, ",");
                 if (end) {
                     av_strlcpy(hls->iv_string, ptr, end - ptr);
                 } else {
                     av_strlcpy(hls->iv_string, ptr, sizeof(hls->iv_string));
                 }
             }
 

         } else if (av_strstart(line, "#", NULL)) {
             continue;
         } else if (line[0]) {
             if (is_segment) {
                 is_segment = 0;
                 new_start_pos = avio_tell(hls->avf->pb);
                 hls->size = new_start_pos - hls->start_pos;
                 av_strlcpy(hls->avf->filename, line, sizeof(line));
                 ret = hls_append_segment(s, hls, hls->duration, hls->start_pos, hls->size);
                 if (ret < 0)
                     goto fail;
                 hls->start_pos = new_start_pos;
             }
         }
     }
 
 fail:
     avio_close(in);
     return ret;
 }
 

 static void hls_free_segments(HLSSegment *p)

 {

     HLSSegment *en;

 
     while(p) {
         en = p;
         p = p->next;
         av_free(en);
     }
 }
 

 static void write_m3u8_head_block(HLSContext *hls, AVIOContext *out, int version,
                                   int target_duration, int64_t sequence)
 {
     avio_printf(out, "#EXTM3U\n");
     avio_printf(out, "#EXT-X-VERSION:%d\n", version);
     if (hls->allowcache == 0 || hls->allowcache == 1) {
         avio_printf(out, "#EXT-X-ALLOW-CACHE:%s\n", hls->allowcache == 0 ? "NO" : "YES");
     }
     avio_printf(out, "#EXT-X-TARGETDURATION:%d\n", target_duration);
     avio_printf(out, "#EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
     av_log(hls, AV_LOG_VERBOSE, "EXT-X-MEDIA-SEQUENCE:%"PRId64"\n", sequence);
 }
 

 static void hls_rename_temp_file(AVFormatContext *s, AVFormatContext *oc)
 {
     size_t len = strlen(oc->filename);
     char final_filename[sizeof(oc->filename)];
 
     av_strlcpy(final_filename, oc->filename, len);
     final_filename[len-4] = '\0';
     ff_rename(oc->filename, final_filename, s);
     oc->filename[len-4] = '\0';
 }
 

 static int hls_window(AVFormatContext *s, int last)
 {
     HLSContext *hls = s->priv_data;

     HLSSegment *en;

     int target_duration = 0;

     int ret = 0;

     AVIOContext *out = NULL;

     AVIOContext *sub_out = NULL;

     char temp_filename[1024];

     int64_t sequence = FFMAX(hls->start_sequence, hls->sequence - hls->nb_entries);

     int version = 3;

     const char *proto = avio_find_protocol_name(s->filename);
     int use_rename = proto && !strcmp(proto, "file");

     static unsigned warned_non_file;

     char *key_uri = NULL;
     char *iv_string = NULL;

     AVDictionary *options = NULL;

     double prog_date_time = hls->initial_prog_date_time;

     int byterange_mode = (hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size > 0);
 
     if (byterange_mode) {
         version = 4;
         sequence = 0;
     }

     if (hls->segment_type == SEGMENT_TYPE_FMP4) {
         version = 7;
     }
 

     if (!use_rename && !warned_non_file++)

         av_log(s, AV_LOG_ERROR, "Cannot use rename on non file protocol, this may lead to races and temporary partial files\n");

     set_http_options(s, &options, hls);

     snprintf(temp_filename, sizeof(temp_filename), use_rename ? "%s.tmp" : "%s", s->filename);

     if ((ret = s->io_open(s, &out, temp_filename, AVIO_FLAG_WRITE, &options)) < 0)

         goto fail;
 

     for (en = hls->segments; en; en = en->next) {

         if (target_duration <= en->duration)
             target_duration = get_int_from_double(en->duration);

     }
 

     hls->discontinuity_set = 0;

     write_m3u8_head_block(hls, out, version, target_duration, sequence);

     if (hls->pl_type == PLAYLIST_TYPE_EVENT) {
         avio_printf(out, "#EXT-X-PLAYLIST-TYPE:EVENT\n");
     } else if (hls->pl_type == PLAYLIST_TYPE_VOD) {
         avio_printf(out, "#EXT-X-PLAYLIST-TYPE:VOD\n");
     }

     if((hls->flags & HLS_DISCONT_START) && sequence==hls->start_sequence && hls->discontinuity_set==0 ){
         avio_printf(out, "#EXT-X-DISCONTINUITY\n");
         hls->discontinuity_set = 1;
     }

     for (en = hls->segments; en; en = en->next) {

         if ((hls->encrypt || hls->key_info_file) && (!key_uri || strcmp(en->key_uri, key_uri) ||

                                     av_strcasecmp(en->iv_string, iv_string))) {
             avio_printf(out, "#EXT-X-KEY:METHOD=AES-128,URI=\"%s\"", en->key_uri);
             if (*en->iv_string)
                 avio_printf(out, ",IV=0x%s", en->iv_string);
             avio_printf(out, "\n");
             key_uri = en->key_uri;
             iv_string = en->iv_string;
         }
 

         if (en->discont) {
             avio_printf(out, "#EXT-X-DISCONTINUITY\n");
         }
 

         if ((hls->segment_type == SEGMENT_TYPE_FMP4) && (en == hls->segments)) {
             avio_printf(out, "#EXT-X-MAP:URI=\"%s\"", hls->fmp4_init_filename);
             if (hls->flags & HLS_SINGLE_FILE) {
                 avio_printf(out, ",BYTERANGE=\"%"PRId64"@%"PRId64"\"", en->size, en->pos);
             }
             avio_printf(out, "\n");

         }

         if (hls->flags & HLS_ROUND_DURATIONS)
             avio_printf(out, "#EXTINF:%ld,\n",  lrint(en->duration));
         else
             avio_printf(out, "#EXTINF:%f,\n", en->duration);
         if (byterange_mode)
             avio_printf(out, "#EXT-X-BYTERANGE:%"PRId64"@%"PRId64"\n",
                         en->size, en->pos);

         if (hls->flags & HLS_PROGRAM_DATE_TIME) {

             time_t tt, wrongsecs;

             int milli;
             struct tm *tm, tmpbuf;
             char buf0[128], buf1[128];
             tt = (int64_t)prog_date_time;
             milli = av_clip(lrint(1000*(prog_date_time - tt)), 0, 999);
             tm = localtime_r(&tt, &tmpbuf);

             strftime(buf0, sizeof(buf0), "%Y-%m-%dT%H:%M:%S", tm);

             if (!strftime(buf1, sizeof(buf1), "%z", tm) || buf1[1]<'0' ||buf1[1]>'2') {
                 int tz_min, dst = tm->tm_isdst;
                 tm = gmtime_r(&tt, &tmpbuf);
                 tm->tm_isdst = dst;
                 wrongsecs = mktime(tm);
                 tz_min = (abs(wrongsecs - tt) + 30) / 60;
                 snprintf(buf1, sizeof(buf1),
                          "%c%02d%02d",
                          wrongsecs <= tt ? '+' : '-',
                          tz_min / 60,
                          tz_min % 60);
             }

             avio_printf(out, "#EXT-X-PROGRAM-DATE-TIME:%s.%03d%s\n", buf0, milli, buf1);
             prog_date_time += en->duration;
         }

         if (hls->baseurl)
             avio_printf(out, "%s", hls->baseurl);
         avio_printf(out, "%s\n", en->filename);

     }
 

     if (last && (hls->flags & HLS_OMIT_ENDLIST)==0)

         avio_printf(out, "#EXT-X-ENDLIST\n");

     if( hls->vtt_m3u8_name ) {

         if ((ret = s->io_open(s, &sub_out, hls->vtt_m3u8_name, AVIO_FLAG_WRITE, &options)) < 0)

             goto fail;

         write_m3u8_head_block(hls, sub_out, version, target_duration, sequence);

 
         for (en = hls->segments; en; en = en->next) {
             avio_printf(sub_out, "#EXTINF:%f,\n", en->duration);

             if (byterange_mode)

                  avio_printf(sub_out, "#EXT-X-BYTERANGE:%"PRIi64"@%"PRIi64"\n",
                          en->size, en->pos);
             if (hls->baseurl)
                 avio_printf(sub_out, "%s", hls->baseurl);
             avio_printf(sub_out, "%s\n", en->sub_filename);
         }
 
         if (last)
             avio_printf(sub_out, "#EXT-X-ENDLIST\n");
 
     }
 

 fail:

     av_dict_free(&options);

     ff_format_io_close(s, &out);

     ff_format_io_close(s, &sub_out);

     if (ret >= 0 && use_rename)

         ff_rename(temp_filename, s->filename, s);

     return ret;
 }
 
 static int hls_start(AVFormatContext *s)
 {
     HLSContext *c = s->priv_data;
     AVFormatContext *oc = c->avf;

     AVFormatContext *vtt_oc = c->vtt_avf;

     AVDictionary *options = NULL;
     char *filename, iv_string[KEYSIZE*2 + 1];

     int err = 0;
 

     if (c->flags & HLS_SINGLE_FILE) {

         av_strlcpy(oc->filename, c->basename,
                    sizeof(oc->filename));

         if (c->vtt_basename)
             av_strlcpy(vtt_oc->filename, c->vtt_basename,
                   sizeof(vtt_oc->filename));

     } else if (c->max_seg_size > 0) {

         if (replace_int_data_in_filename(oc->filename, sizeof(oc->filename),

 #if FF_API_HLS_WRAP

             c->basename, 'd', c->wrap ? c->sequence % c->wrap : c->sequence) < 1) {

 #else
             c->basename, 'd', c->sequence) < 1) {
 #endif

                 av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s', you can try to use -use_localtime 1 with it\n", c->basename);
                 return AVERROR(EINVAL);
         }

     } else {

         if (c->use_localtime) {
             time_t now0;
             struct tm *tm, tmpbuf;
             time(&now0);
             tm = localtime_r(&now0, &tmpbuf);
             if (!strftime(oc->filename, sizeof(oc->filename), c->basename, tm)) {
                 av_log(oc, AV_LOG_ERROR, "Could not get segment filename with use_localtime\n");
                 return AVERROR(EINVAL);
             }

 
             err = sls_flag_use_localtime_filename(oc, c);
             if (err < 0) {
                 return AVERROR(ENOMEM);

             }

             if (c->use_localtime_mkdir) {
                 const char *dir;
                 char *fn_copy = av_strdup(oc->filename);
                 if (!fn_copy) {
                     return AVERROR(ENOMEM);
                 }
                 dir = av_dirname(fn_copy);

                 if (mkdir_p(dir) == -1 && errno != EEXIST) {

                     av_log(oc, AV_LOG_ERROR, "Could not create directory %s with use_localtime_mkdir\n", dir);
                     av_free(fn_copy);
                     return AVERROR(errno);
                 }
                 av_free(fn_copy);
             }

         } else if (replace_int_data_in_filename(oc->filename, sizeof(oc->filename),

 #if FF_API_HLS_WRAP

                    c->basename, 'd', c->wrap ? c->sequence % c->wrap : c->sequence) < 1) {

 #else
                    c->basename, 'd', c->sequence) < 1) {
 #endif

             av_log(oc, AV_LOG_ERROR, "Invalid segment filename template '%s' you can try to use -use_localtime 1 with it\n", c->basename);

             return AVERROR(EINVAL);
         }

         if( c->vtt_basename) {

             if (replace_int_data_in_filename(vtt_oc->filename, sizeof(vtt_oc->filename),

 #if FF_API_HLS_WRAP

                 c->vtt_basename, 'd', c->wrap ? c->sequence % c->wrap : c->sequence) < 1) {

 #else
                 c->vtt_basename, 'd', c->sequence) < 1) {
 #endif

                 av_log(vtt_oc, AV_LOG_ERROR, "Invalid segment filename template '%s'\n", c->vtt_basename);
                 return AVERROR(EINVAL);
             }
        }
     }

     c->number++;

     set_http_options(s, &options, c);

     if (c->flags & HLS_TEMP_FILE) {
         av_strlcat(oc->filename, ".tmp", sizeof(oc->filename));
     }
 

     if (c->key_info_file || c->encrypt) {
         if (c->key_info_file && c->encrypt) {
             av_log(s, AV_LOG_WARNING, "Cannot use both -hls_key_info_file and -hls_enc,"
                   " will use -hls_key_info_file priority\n");
         }

         if (c->number <= 1 || (c->flags & HLS_PERIODIC_REKEY)) {

             if (c->key_info_file) {
                 if ((err = hls_encryption_start(s)) < 0)
                     goto fail;
             } else {
                 if ((err = do_encrypt(s)) < 0)
                     goto fail;
             }

         }

         if ((err = av_dict_set(&options, "encryption_key", c->key_string, 0))
                 < 0)

             goto fail;

         err = av_strlcpy(iv_string, c->iv_string, sizeof(iv_string));
         if (!err)
             snprintf(iv_string, sizeof(iv_string), "%032"PRIx64, c->sequence);
         if ((err = av_dict_set(&options, "encryption_iv", iv_string, 0)) < 0)

            goto fail;

 
         filename = av_asprintf("crypto:%s", oc->filename);
         if (!filename) {

             err = AVERROR(ENOMEM);
             goto fail;

         }

         err = s->io_open(s, &oc->pb, filename, AVIO_FLAG_WRITE, &options);

         av_free(filename);
         av_dict_free(&options);
         if (err < 0)
             return err;
     } else

         if ((err = s->io_open(s, &oc->pb, oc->filename, AVIO_FLAG_WRITE, &options)) < 0)

             goto fail;

     if (c->vtt_basename) {

         set_http_options(s, &options, c);

         if ((err = s->io_open(s, &vtt_oc->pb, vtt_oc->filename, AVIO_FLAG_WRITE, &options)) < 0)

             goto fail;

     }

     av_dict_free(&options);

     if (c->segment_type == SEGMENT_TYPE_FMP4 && !(c->flags & HLS_SINGLE_FILE)) {

             write_styp(oc->pb);
     } else {
         /* We only require one PAT/PMT per segment. */
         if (oc->oformat->priv_class && oc->priv_data) {
             char period[21];

             snprintf(period, sizeof(period), "%d", (INT_MAX / 2) - 1);

             av_opt_set(oc->priv_data, "mpegts_flags", "resend_headers", 0);
             av_opt_set(oc->priv_data, "sdt_period", period, 0);
             av_opt_set(oc->priv_data, "pat_period", period, 0);
         }

     }

     if (c->vtt_basename) {
         err = avformat_write_header(vtt_oc,NULL);
         if (err < 0)
             return err;
     }

     return 0;

 fail:
     av_dict_free(&options);
 
     return err;

 }
 

 static const char * get_default_pattern_localtime_fmt(AVFormatContext *s)

 {
     char b[21];
     time_t t = time(NULL);
     struct tm *p, tmbuf;

     HLSContext *hls = s->priv_data;
 

     p = localtime_r(&t, &tmbuf);
     // no %s support when strftime returned error or left format string unchanged

     // also no %s support on MSVC, which invokes the invalid parameter handler on unsupported format strings, instead of returning an error

     if (hls->segment_type == SEGMENT_TYPE_FMP4) {
         return (HAVE_LIBC_MSVCRT || !strftime(b, sizeof(b), "%s", p) || !strcmp(b, "%s")) ? "-%Y%m%d%H%M%S.m4s" : "-%s.m4s";
     }

     return (HAVE_LIBC_MSVCRT || !strftime(b, sizeof(b), "%s", p) || !strcmp(b, "%s")) ? "-%Y%m%d%H%M%S.ts" : "-%s.ts";

 }
 

 static int hls_write_header(AVFormatContext *s)
 {
     HLSContext *hls = s->priv_data;
     int ret, i;

     char *p = NULL;

     const char *pattern = "%d.ts";

     const char *pattern_localtime_fmt = get_default_pattern_localtime_fmt(s);

     const char *vtt_pattern = "%d.vtt";

     AVDictionary *options = NULL;

     int basename_size = 0;
     int vtt_basename_size = 0;

     int fmp4_init_filename_len = strlen(hls->fmp4_init_filename) + 1;

     if (hls->segment_type == SEGMENT_TYPE_FMP4) {
         pattern = "%d.m4s";

     }

     if ((hls->start_sequence_source_type == HLS_START_SEQUENCE_AS_SECONDS_SINCE_EPOCH) ||
         (hls->start_sequence_source_type == HLS_START_SEQUENCE_AS_FORMATTED_DATETIME)) {

         time_t t = time(NULL); // we will need it in either case

         if (hls->start_sequence_source_type == HLS_START_SEQUENCE_AS_SECONDS_SINCE_EPOCH) {

             hls->start_sequence = (int64_t)t;

         } else if (hls->start_sequence_source_type == HLS_START_SEQUENCE_AS_FORMATTED_DATETIME) {

             char b[15];
             struct tm *p, tmbuf;
             if (!(p = localtime_r(&t, &tmbuf)))
                 return AVERROR(ENOMEM);
             if (!strftime(b, sizeof(b), "%Y%m%d%H%M%S", p))
                 return AVERROR(ENOMEM);
             hls->start_sequence = strtoll(b, NULL, 10);
         }
         av_log(hls, AV_LOG_DEBUG, "start_number evaluated to %"PRId64"\n", hls->start_sequence);
     }
 

     hls->sequence       = hls->start_sequence;

     hls->recording_time = (hls->init_time ? hls->init_time : hls->time) * AV_TIME_BASE;

     hls->start_pts      = AV_NOPTS_VALUE;

     hls->current_segment_final_filename_fmt[0] = '\0';

     if (hls->flags & HLS_PROGRAM_DATE_TIME) {
         time_t now0;
         time(&now0);
         hls->initial_prog_date_time = now0;
     }
 

     if (hls->format_options_str) {
         ret = av_dict_parse_string(&hls->format_options, hls->format_options_str, "=", ":", 0);
         if (ret < 0) {
             av_log(s, AV_LOG_ERROR, "Could not parse format options list '%s'\n", hls->format_options_str);
             goto fail;
         }
     }
 

     for (i = 0; i < s->nb_streams; i++) {

         hls->has_video +=

             s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO;

         hls->has_subtitle +=

             s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE;

     }

 
     if (hls->has_video > 1)
         av_log(s, AV_LOG_WARNING,
                "More than a single video stream present, "
                "expect issues decoding it.\n");
 

     if (hls->segment_type == SEGMENT_TYPE_FMP4) {
         hls->oformat = av_guess_format("mp4", NULL, NULL);
     } else {
         hls->oformat = av_guess_format("mpegts", NULL, NULL);
     }

 
     if (!hls->oformat) {
         ret = AVERROR_MUXER_NOT_FOUND;
         goto fail;
     }
 

     if(hls->has_subtitle) {
         hls->vtt_oformat = av_guess_format("webvtt", NULL, NULL);
         if (!hls->oformat) {
             ret = AVERROR_MUXER_NOT_FOUND;
             goto fail;
         }
     }
 

     if (hls->segment_filename) {
         hls->basename = av_strdup(hls->segment_filename);
         if (!hls->basename) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }
     } else {

         if (hls->flags & HLS_SINGLE_FILE) {
             if (hls->segment_type == SEGMENT_TYPE_FMP4) {
                 pattern = ".m4s";
             } else {
                 pattern = ".ts";
             }
         }

         if (hls->use_localtime) {
             basename_size = strlen(s->filename) + strlen(pattern_localtime_fmt) + 1;
         } else {
             basename_size = strlen(s->filename) + strlen(pattern) + 1;
         }

         hls->basename = av_malloc(basename_size);
         if (!hls->basename) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }

         av_strlcpy(hls->basename, s->filename, basename_size);

         p = strrchr(hls->basename, '.');
         if (p)
             *p = '\0';

         if (hls->use_localtime) {
             av_strlcat(hls->basename, pattern_localtime_fmt, basename_size);
         } else {
             av_strlcat(hls->basename, pattern, basename_size);
         }

     }

     if (hls->segment_type == SEGMENT_TYPE_FMP4) {

         if (av_strcasecmp(hls->fmp4_init_filename, "init.mp4")) {
             hls->base_output_dirname = av_malloc(fmp4_init_filename_len);
             if (!hls->base_output_dirname) {
                 ret = AVERROR(ENOMEM);
                 goto fail;
             }
             av_strlcpy(hls->base_output_dirname, hls->fmp4_init_filename, fmp4_init_filename_len);

         } else {

             if (basename_size > 0) {
                 hls->base_output_dirname = av_malloc(basename_size);
             } else {

                 hls->base_output_dirname = av_malloc(strlen(hls->fmp4_init_filename) + 1);

             }
             if (!hls->base_output_dirname) {
                 ret = AVERROR(ENOMEM);
                 goto fail;
             }

             if (basename_size > 0) {
                 av_strlcpy(hls->base_output_dirname, s->filename, basename_size);
                 p = strrchr(hls->base_output_dirname, '/');
             }
             if (p) {
                 *(p + 1) = '\0';
                 av_strlcat(hls->base_output_dirname, hls->fmp4_init_filename, basename_size);
             } else {
                 av_strlcpy(hls->base_output_dirname, hls->fmp4_init_filename, fmp4_init_filename_len);
             }

         }

     }

     if (!hls->use_localtime) {

         ret = sls_flag_check_duration_size_index(hls);
         if (ret < 0) {

              goto fail;
         }
     } else {

         ret = sls_flag_check_duration_size(hls);
         if (ret < 0) {

              goto fail;
         }

     }

     if(hls->has_subtitle) {
 
         if (hls->flags & HLS_SINGLE_FILE)
             vtt_pattern = ".vtt";
         vtt_basename_size = strlen(s->filename) + strlen(vtt_pattern) + 1;
         hls->vtt_basename = av_malloc(vtt_basename_size);
         if (!hls->vtt_basename) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }
         hls->vtt_m3u8_name = av_malloc(vtt_basename_size);
         if (!hls->vtt_m3u8_name ) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }
         av_strlcpy(hls->vtt_basename, s->filename, vtt_basename_size);
         p = strrchr(hls->vtt_basename, '.');
         if (p)
             *p = '\0';
 
         if( hls->subtitle_filename ) {
             strcpy(hls->vtt_m3u8_name, hls->subtitle_filename);
         } else {
             strcpy(hls->vtt_m3u8_name, hls->vtt_basename);
             av_strlcat(hls->vtt_m3u8_name, "_vtt.m3u8", vtt_basename_size);
         }
         av_strlcat(hls->vtt_basename, vtt_pattern, vtt_basename_size);
     }
 

     if ((hls->flags & HLS_SINGLE_FILE) && (hls->segment_type == SEGMENT_TYPE_FMP4)) {
         hls->fmp4_init_filename  = av_strdup(hls->basename);
         if (!hls->fmp4_init_filename) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }
     }
 

     if ((ret = hls_mux_init(s)) < 0)
         goto fail;
 

     if (hls->flags & HLS_APPEND_LIST) {
         parse_playlist(s, s->filename);

         hls->discontinuity = 1;

         if (hls->init_time > 0) {
             av_log(s, AV_LOG_WARNING, "append_list mode does not support hls_init_time,"
                    " hls_init_time value will have no effect\n");
             hls->init_time = 0;
             hls->recording_time = hls->time * AV_TIME_BASE;
         }

     }
 

     if (hls->segment_type != SEGMENT_TYPE_FMP4 || hls->flags & HLS_SINGLE_FILE) {

         if ((ret = hls_start(s)) < 0)
             goto fail;
     }

     av_dict_copy(&options, hls->format_options, 0);
     ret = avformat_write_header(hls->avf, &options);
     if (av_dict_count(options)) {
         av_log(s, AV_LOG_ERROR, "Some of provided format options in '%s' are not recognized\n", hls->format_options_str);
         ret = AVERROR(EINVAL);

         goto fail;

     }

     //av_assert0(s->nb_streams == hls->avf->nb_streams);

     for (i = 0; i < s->nb_streams; i++) {

         AVStream *inner_st;

         AVStream *outer_st = s->streams[i];

 
         if (hls->max_seg_size > 0) {
             if ((outer_st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) &&
                 (outer_st->codecpar->bit_rate > hls->max_seg_size)) {
                 av_log(s, AV_LOG_WARNING, "Your video bitrate is bigger than hls_segment_size, "
                        "(%"PRId64 " > %"PRId64 "), the result maybe not be what you want.",
                        outer_st->codecpar->bit_rate, hls->max_seg_size);
             }
         }
 

         if (outer_st->codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE)

             inner_st = hls->avf->streams[i];
         else if (hls->vtt_avf)
             inner_st = hls->vtt_avf->streams[0];
         else {

             /* We have a subtitle stream, when the user does not want one */

             inner_st = NULL;
             continue;
         }

         avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits, inner_st->time_base.num, inner_st->time_base.den);

     }

 fail:

 
     av_dict_free(&options);

     if (ret < 0) {

         av_freep(&hls->fmp4_init_filename);

         av_freep(&hls->basename);

         av_freep(&hls->vtt_basename);

         av_freep(&hls->key_basename);

         if (hls->avf)
             avformat_free_context(hls->avf);

         if (hls->vtt_avf)
             avformat_free_context(hls->vtt_avf);
 

     }
     return ret;
 }
 
 static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     HLSContext *hls = s->priv_data;

     AVFormatContext *oc = NULL;

     AVStream *st = s->streams[pkt->stream_index];
     int64_t end_pts = hls->recording_time * hls->number;

     int is_ref_pkt = 1;

     int ret = 0, can_split = 1;

     int stream_index = 0;

     int range_length = 0;
     uint8_t *buffer = NULL;

     if (hls->sequence - hls->nb_entries > hls->start_sequence && hls->init_time > 0) {
         /* reset end_pts, hls->recording_time at end of the init hls list */
         int init_list_dur = hls->init_time * hls->nb_entries * AV_TIME_BASE;
         int after_init_list_dur = (hls->sequence - hls->nb_entries ) * hls->time * AV_TIME_BASE;
         hls->recording_time = hls->time * AV_TIME_BASE;
         end_pts = init_list_dur + after_init_list_dur ;
     }
 

     if( st->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE ) {

         oc = hls->vtt_avf;
         stream_index = 0;
     } else {
         oc = hls->avf;
         stream_index = pkt->stream_index;
     }

     if (hls->start_pts == AV_NOPTS_VALUE) {
         hls->start_pts = pkt->pts;
         hls->end_pts   = pkt->pts;
     }
 

     if (hls->has_video) {

         can_split = st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&

                     ((pkt->flags & AV_PKT_FLAG_KEY) || (hls->flags & HLS_SPLIT_BY_TIME));

         is_ref_pkt = st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO;

     }

     if (pkt->pts == AV_NOPTS_VALUE)
         is_ref_pkt = can_split = 0;

     if (is_ref_pkt) {
         if (hls->new_start) {
             hls->new_start = 0;
             hls->duration = (double)(pkt->pts - hls->end_pts)
                                        * st->time_base.num / st->time_base.den;
             hls->dpp = (double)(pkt->duration) * st->time_base.num / st->time_base.den;
         } else {

             if (pkt->duration) {
                 hls->duration += (double)(pkt->duration) * st->time_base.num / st->time_base.den;
             } else {
                 av_log(s, AV_LOG_WARNING, "pkt->duration = 0, maybe the hls segment duration will not precise\n");
                 hls->duration = (double)(pkt->pts - hls->end_pts) * st->time_base.num / st->time_base.den;
             }

         }

     }

     if (hls->packets_written && can_split && av_compare_ts(pkt->pts - hls->start_pts, st->time_base,

                                    end_pts, AV_TIME_BASE_Q) >= 0) {

         int64_t new_start_pos;

         char *old_filename = av_strdup(hls->avf->filename);

         int byterange_mode = (hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size > 0);

 
         if (!old_filename) {
             return AVERROR(ENOMEM);
         }
 

         av_write_frame(hls->avf, NULL); /* Flush any buffered data */

 
         new_start_pos = avio_tell(hls->avf->pb);
         hls->size = new_start_pos - hls->start_pos;

         if (!byterange_mode) {

             if (hls->segment_type == SEGMENT_TYPE_FMP4 && !hls->init_range_length) {
                 avio_flush(oc->pb);
                 range_length = avio_close_dyn_buf(oc->pb, &buffer);
                 avio_write(hls->out, buffer, range_length);
                 hls->init_range_length = range_length;
                 avio_open_dyn_buf(&oc->pb);
                 hls->packets_written = 0;
                 ff_format_io_close(s, &hls->out);
             } else {
                 ff_format_io_close(s, &oc->pb);
             }

             if (hls->vtt_avf) {
                 ff_format_io_close(s, &hls->vtt_avf->pb);
             }

         }

         if ((hls->flags & HLS_TEMP_FILE) && oc->filename[0]) {
             if (!(hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size <= 0))

                 if ((hls->avf->oformat->priv_class && hls->avf->priv_data) && hls->segment_type != SEGMENT_TYPE_FMP4)

                     av_opt_set(hls->avf->priv_data, "mpegts_flags", "resend_headers", 0);
             hls_rename_temp_file(s, oc);
         }
 

         if (hls->fmp4_init_mode) {
             hls->number--;
         }
 

         if (!hls->fmp4_init_mode || byterange_mode)

             ret = hls_append_segment(s, hls, hls->duration, hls->start_pos, hls->size);
 

         hls->start_pos = new_start_pos;

         if (ret < 0) {
             av_free(old_filename);

             return ret;

         }

         hls->end_pts = pkt->pts;

         hls->duration = 0;

         hls->fmp4_init_mode = 0;

         if (hls->flags & HLS_SINGLE_FILE) {
             hls->number++;

         } else if (hls->max_seg_size > 0) {
             if (hls->start_pos >= hls->max_seg_size) {
                 hls->sequence++;

                 sls_flag_file_rename(hls, old_filename);

                 ret = hls_start(s);
                 hls->start_pos = 0;
                 /* When split segment by byte, the duration is short than hls_time,
                  * so it is not enough one segment duration as hls_time, */
                 hls->number--;
             }
             hls->number++;

         } else {

             sls_flag_file_rename(hls, old_filename);

             ret = hls_start(s);
         }

         av_free(old_filename);

         if (ret < 0) {

             return ret;

         }

         if (!hls->fmp4_init_mode || byterange_mode)
             if ((ret = hls_window(s, 0)) < 0) {
                 return ret;
             }

     }
 

     hls->packets_written++;

     ret = ff_write_chained(oc, stream_index, pkt, s, 0);

 
     return ret;
 }
 
 static int hls_write_trailer(struct AVFormatContext *s)
 {
     HLSContext *hls = s->priv_data;
     AVFormatContext *oc = hls->avf;

     AVFormatContext *vtt_oc = hls->vtt_avf;

     char *old_filename = av_strdup(hls->avf->filename);
 
     if (!old_filename) {
         return AVERROR(ENOMEM);
     }
 

 
     av_write_trailer(oc);

     if (oc->pb) {
         hls->size = avio_tell(hls->avf->pb) - hls->start_pos;

         ff_format_io_close(s, &oc->pb);

 
         if ((hls->flags & HLS_TEMP_FILE) && oc->filename[0]) {
             hls_rename_temp_file(s, oc);
         }
 

         /* after av_write_trailer, then duration + 1 duration per packet */
         hls_append_segment(s, hls, hls->duration + hls->dpp, hls->start_pos, hls->size);

     }

     sls_flag_file_rename(hls, old_filename);

     if (vtt_oc) {
         if (vtt_oc->pb)
             av_write_trailer(vtt_oc);
         hls->size = avio_tell(hls->vtt_avf->pb) - hls->start_pos;

         ff_format_io_close(s, &vtt_oc->pb);

     }

     av_freep(&hls->basename);

     av_freep(&hls->base_output_dirname);

     av_freep(&hls->key_basename);

     avformat_free_context(oc);

     hls->avf = NULL;
     hls_window(s, 1);
 

     av_freep(&hls->fmp4_init_filename);

     if (vtt_oc) {
         av_freep(&hls->vtt_basename);
         av_freep(&hls->vtt_m3u8_name);
         avformat_free_context(vtt_oc);
     }
 

     hls_free_segments(hls->segments);
     hls_free_segments(hls->old_segments);

     av_free(old_filename);

     return 0;
 }
 
 #define OFFSET(x) offsetof(HLSContext, x)
 #define E AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {

     {"start_number",  "set first number in the sequence",        OFFSET(start_sequence),AV_OPT_TYPE_INT64,  {.i64 = 0},     0, INT64_MAX, E},

     {"hls_time",      "set segment length in seconds",           OFFSET(time),    AV_OPT_TYPE_FLOAT,  {.dbl = 2},     0, FLT_MAX, E},

     {"hls_init_time", "set segment length in seconds at init list",           OFFSET(init_time),    AV_OPT_TYPE_FLOAT,  {.dbl = 0},     0, FLT_MAX, E},

     {"hls_list_size", "set maximum number of playlist entries",  OFFSET(max_nb_segments),    AV_OPT_TYPE_INT,    {.i64 = 5},     0, INT_MAX, E},

     {"hls_ts_options","set hls mpegts list of options for the container format used for hls", OFFSET(format_options_str), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},

     {"hls_vtt_options","set hls vtt list of options for the container format used for hls", OFFSET(vtt_format_options_str), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},

 #if FF_API_HLS_WRAP
     {"hls_wrap",      "set number after which the index wraps (will be deprecated)",  OFFSET(wrap),    AV_OPT_TYPE_INT,    {.i64 = 0},     0, INT_MAX, E},
 #endif

     {"hls_allow_cache", "explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments", OFFSET(allowcache), AV_OPT_TYPE_INT, {.i64 = -1}, INT_MIN, INT_MAX, E},

     {"hls_base_url",  "url to prepend to each playlist entry",   OFFSET(baseurl), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E},

     {"hls_segment_filename", "filename template for segment files", OFFSET(segment_filename),   AV_OPT_TYPE_STRING, {.str = NULL},            0,       0,         E},

     {"hls_segment_size", "maximum size per segment file, (in bytes)",  OFFSET(max_seg_size),    AV_OPT_TYPE_INT,    {.i64 = 0},               0,       INT_MAX,   E},

     {"hls_key_info_file",    "file with key URI and key file path", OFFSET(key_info_file),      AV_OPT_TYPE_STRING, {.str = NULL},            0,       0,         E},

     {"hls_enc",    "enable AES128 encryption support", OFFSET(encrypt),      AV_OPT_TYPE_BOOL, {.i64 = 0},            0,       1,         E},
     {"hls_enc_key",    "hex-coded 16 byte key to encrypt the segments", OFFSET(key),      AV_OPT_TYPE_STRING, .flags = E},
     {"hls_enc_key_url",    "url to access the key to decrypt the segments", OFFSET(key_url),      AV_OPT_TYPE_STRING, {.str = NULL},            0,       0,         E},
     {"hls_enc_iv",    "hex-coded 16 byte initialization vector", OFFSET(iv),      AV_OPT_TYPE_STRING, .flags = E},

     {"hls_subtitle_path",     "set path of hls subtitles", OFFSET(subtitle_filename), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},

     {"hls_segment_type",     "set hls segment files type", OFFSET(segment_type), AV_OPT_TYPE_INT, {.i64 = SEGMENT_TYPE_MPEGTS }, 0, SEGMENT_TYPE_FMP4, E, "segment_type"},

     {"mpegts",   "make segment file to mpegts files in m3u8", 0, AV_OPT_TYPE_CONST, {.i64 = SEGMENT_TYPE_MPEGTS }, 0, UINT_MAX,   E, "segment_type"},

     {"fmp4",   "make segment file to fragment mp4 files in m3u8", 0, AV_OPT_TYPE_CONST, {.i64 = SEGMENT_TYPE_FMP4 }, 0, UINT_MAX,   E, "segment_type"},

     {"hls_fmp4_init_filename", "set fragment mp4 file init filename", OFFSET(fmp4_init_filename),   AV_OPT_TYPE_STRING, {.str = "init.mp4"},            0,       0,         E},

     {"hls_flags",     "set flags affecting HLS playlist and media file generation", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0 }, 0, UINT_MAX, E, "flags"},
     {"single_file",   "generate a single media file indexed with byte ranges", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_SINGLE_FILE }, 0, UINT_MAX,   E, "flags"},

     {"temp_file", "write segment to temporary file and rename when complete", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_TEMP_FILE }, 0, UINT_MAX,   E, "flags"},

     {"delete_segments", "delete segment files that are no longer part of the playlist", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_DELETE_SEGMENTS }, 0, UINT_MAX,   E, "flags"},

     {"round_durations", "round durations in m3u8 to whole numbers", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_ROUND_DURATIONS }, 0, UINT_MAX,   E, "flags"},

     {"discont_start", "start the playlist with a discontinuity tag", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_DISCONT_START }, 0, UINT_MAX,   E, "flags"},

     {"omit_endlist", "Do not append an endlist when ending stream", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_OMIT_ENDLIST }, 0, UINT_MAX,   E, "flags"},

     {"split_by_time", "split the hls segment by time which user set by hls_time", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_SPLIT_BY_TIME }, 0, UINT_MAX,   E, "flags"},

     {"append_list", "append the new segments into old hls segment list", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_APPEND_LIST }, 0, UINT_MAX,   E, "flags"},

     {"program_date_time", "add EXT-X-PROGRAM-DATE-TIME", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_PROGRAM_DATE_TIME }, 0, UINT_MAX,   E, "flags"},

     {"second_level_segment_index", "include segment index in segment filenames when use_localtime", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_SECOND_LEVEL_SEGMENT_INDEX }, 0, UINT_MAX,   E, "flags"},

     {"second_level_segment_duration", "include segment duration in segment filenames when use_localtime", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_SECOND_LEVEL_SEGMENT_DURATION }, 0, UINT_MAX,   E, "flags"},
     {"second_level_segment_size", "include segment size in segment filenames when use_localtime", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_SECOND_LEVEL_SEGMENT_SIZE }, 0, UINT_MAX,   E, "flags"},

     {"periodic_rekey", "reload keyinfo file periodically for re-keying", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_PERIODIC_REKEY }, 0, UINT_MAX,   E, "flags"},

     {"use_localtime", "set filename expansion with strftime at segment creation", OFFSET(use_localtime), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, E },
     {"use_localtime_mkdir", "create last directory component in strftime-generated filename", OFFSET(use_localtime_mkdir), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, E },

     {"hls_playlist_type", "set the HLS playlist type", OFFSET(pl_type), AV_OPT_TYPE_INT, {.i64 = PLAYLIST_TYPE_NONE }, 0, PLAYLIST_TYPE_NB-1, E, "pl_type" },
     {"event", "EVENT playlist", 0, AV_OPT_TYPE_CONST, {.i64 = PLAYLIST_TYPE_EVENT }, INT_MIN, INT_MAX, E, "pl_type" },
     {"vod", "VOD playlist", 0, AV_OPT_TYPE_CONST, {.i64 = PLAYLIST_TYPE_VOD }, INT_MIN, INT_MAX, E, "pl_type" },

     {"method", "set the HTTP method(default: PUT)", OFFSET(method), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},

     {"hls_start_number_source", "set source of first number in sequence", OFFSET(start_sequence_source_type), AV_OPT_TYPE_INT, {.i64 = HLS_START_SEQUENCE_AS_START_NUMBER }, 0, HLS_START_SEQUENCE_AS_FORMATTED_DATETIME, E, "start_sequence_source_type" },
     {"generic", "start_number value (default)", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_START_SEQUENCE_AS_START_NUMBER }, INT_MIN, INT_MAX, E, "start_sequence_source_type" },
     {"epoch", "seconds since epoch", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_START_SEQUENCE_AS_SECONDS_SINCE_EPOCH }, INT_MIN, INT_MAX, E, "start_sequence_source_type" },
     {"datetime", "current datetime as YYYYMMDDhhmmss", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_START_SEQUENCE_AS_FORMATTED_DATETIME }, INT_MIN, INT_MAX, E, "start_sequence_source_type" },

     {"http_user_agent", "override User-Agent field in HTTP header", OFFSET(user_agent), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},

     { NULL },
 };
 
 static const AVClass hls_class = {
     .class_name = "hls muxer",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 
 AVOutputFormat ff_hls_muxer = {
     .name           = "hls",

     .long_name      = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),

     .extensions     = "m3u8",
     .priv_data_size = sizeof(HLSContext),

     .audio_codec    = AV_CODEC_ID_AAC,
     .video_codec    = AV_CODEC_ID_H264,

     .subtitle_codec = AV_CODEC_ID_WEBVTT,

     .flags          = AVFMT_NOFILE | AVFMT_GLOBALHEADER | AVFMT_ALLOW_FLUSH,

     .write_header   = hls_write_header,
     .write_packet   = hls_write_packet,
     .write_trailer  = hls_write_trailer,
     .priv_class     = &hls_class,
 };