hlsenc.c

/*
 * Apple HTTP Live Streaming segmenter
 * Copyright (c) 2012, Luca Barbato
 * Copyright (c) 2017 Akamai Technologies, Inc.
 *
 * 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"
#if CONFIG_HTTP_PROTOCOL
#include "http.h"
#endif
#include "hlsplaylist.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
#define POSTFIX_PATTERN "_%d"

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),
    HLS_INDEPENDENT_SEGMENTS = (1 << 13),
} HLSFlags;

typedef enum {
    SEGMENT_TYPE_MPEGTS,
    SEGMENT_TYPE_FMP4,
} SegmentType;

typedef struct VariantStream {
    unsigned number;
    int64_t sequence;
    AVOutputFormat *oformat;
    AVOutputFormat *vtt_oformat;
    AVIOContext *out;
    int packets_written;
    int init_range_length;

    AVFormatContext *avf;
    AVFormatContext *vtt_avf;

    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
    int nb_entries;
    int discontinuity_set;
    int discontinuity;

    HLSSegment *segments;
    HLSSegment *last_segment;
    HLSSegment *old_segments;

    char *basename;
    char *vtt_basename;
    char *vtt_m3u8_name;
    char *m3u8_name;

    double initial_prog_date_time;
    char current_segment_final_filename_fmt[1024]; // when renaming segments

    char *fmp4_init_filename;
    char *base_output_dirname;
    int fmp4_init_mode;

    AVStream **streams;
    unsigned int nb_streams;
    int m3u8_created; /* status of media play-list creation */
    char *baseurl;
} VariantStream;

typedef struct HLSContext {
    const AVClass *class;  // Class for private options.
    int64_t start_sequence;
    uint32_t start_sequence_source_type;  // enum StartSequenceSourceType

    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 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;
    int64_t max_seg_size; // every segment file max size

    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;
    int encrypt_started;

    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;
    char *user_agent;

    VariantStream *var_streams;
    unsigned int nb_varstreams;

    int master_m3u8_created; /* status of master play-list creation */
    char *master_m3u8_url; /* URL of the master m3u8 file */
    int version; /* HLS version */
    char *var_stream_map; /* user specified variant stream map string */
    char *master_pl_name;
    unsigned int master_publish_rate;
    int http_persistent;
    AVIOContext *m3u8_out;
    AVIOContext *sub_m3u8_out;
} HLSContext;

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 int is_http_proto(char *filename) {
    const char *proto = avio_find_protocol_name(filename);
    return proto ? (!av_strcasecmp(proto, "http") || !av_strcasecmp(proto, "https")) : 0;
}

static int hlsenc_io_open(AVFormatContext *s, AVIOContext **pb, char *filename,
                          AVDictionary **options) {
    HLSContext *hls = s->priv_data;
    int http_base_proto = filename ? is_http_proto(filename) : 0;
    int err = AVERROR_MUXER_NOT_FOUND;
    if (!*pb || !http_base_proto || !hls->http_persistent) {
        err = s->io_open(s, pb, filename, AVIO_FLAG_WRITE, options);
#if CONFIG_HTTP_PROTOCOL
    } else {
        URLContext *http_url_context = ffio_geturlcontext(*pb);
        av_assert0(http_url_context);
        err = ff_http_do_new_request(http_url_context, filename);
#endif
    }
    return err;
}

static void hlsenc_io_close(AVFormatContext *s, AVIOContext **pb, char *filename) {
    HLSContext *hls = s->priv_data;
    int http_base_proto = filename ? is_http_proto(filename) : 0;

    if (!http_base_proto || !hls->http_persistent || hls->key_info_file || hls->encrypt) {
        ff_format_io_close(s, pb);
    } else {
        avio_flush(*pb);
    }
}

static void set_http_options(AVFormatContext *s, AVDictionary **options, HLSContext *c)
{
    int http_base_proto = is_http_proto(s->filename);

    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);
    if (c->http_persistent)
        av_dict_set_int(options, "multiple_requests", 1, 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 flush_dynbuf(VariantStream *vs, int *range_length)
{
    AVFormatContext *ctx = vs->avf;
    uint8_t *buffer;

    if (!ctx->pb) {
        return AVERROR(EINVAL);
    }

    // flush
    av_write_frame(ctx, NULL);
    avio_flush(ctx->pb);

    // write out to file
    *range_length = avio_close_dyn_buf(ctx->pb, &buffer);
    ctx->pb = NULL;
    avio_write(vs->out, buffer, *range_length);
    av_free(buffer);

    // re-open buffer
    return avio_open_dyn_buf(&ctx->pb);
}

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

    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 = vs->segments;
    while (segment) {
        playlist_duration += segment->duration;
        segment = segment->next;
    }

    segment = vs->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(vs->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 = vs->avf->io_open(vs->avf, &out, path, AVIO_FLAG_WRITE, &options)) < 0)
                goto fail;
            ff_format_io_close(vs->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 = vs->avf->io_open(vs->avf, &out, sub_path, AVIO_FLAG_WRITE, &options)) < 0) {
                    av_free(sub_path);
                    goto fail;
                }
                ff_format_io_close(vs->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, VariantStream *vs)
{
    HLSContext *hls = s->priv_data;
    int ret;
    int len;
    AVIOContext *pb;
    uint8_t key[KEYSIZE];

    len = strlen(s->filename) + 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, vs->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, VariantStream *vs)
{
    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(&vs->avf, vs->oformat, NULL, NULL);
    if (ret < 0)
        return ret;
    oc = vs->avf;

    oc->filename[0]        = '\0';
    oc->oformat            = vs->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(vs->vtt_oformat) {
        ret = avformat_alloc_output_context2(&vs->vtt_avf, vs->vtt_oformat, NULL, NULL);
        if (ret < 0)
            return ret;
        vtt_oc          = vs->vtt_avf;
        vtt_oc->oformat = vs->vtt_oformat;
        av_dict_copy(&vtt_oc->metadata, s->metadata, 0);
    }

    for (i = 0; i < vs->nb_streams; i++) {
        AVStream *st;
        AVFormatContext *loc;
        if (vs->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, vs->streams[i]->codecpar);
        if (!oc->oformat->codec_tag ||
            av_codec_get_id (oc->oformat->codec_tag, vs->streams[i]->codecpar->codec_tag) == st->codecpar->codec_id ||
            av_codec_get_tag(oc->oformat->codec_tag, vs->streams[i]->codecpar->codec_id) <= 0) {
            st->codecpar->codec_tag = vs->streams[i]->codecpar->codec_tag;
        } else {
            st->codecpar->codec_tag = 0;
        }

        st->sample_aspect_ratio = vs->streams[i]->sample_aspect_ratio;
        st->time_base = vs->streams[i]->time_base;
        av_dict_copy(&st->metadata, vs->streams[i]->metadata, 0);
    }

    vs->packets_written = 1;
    vs->start_pos = 0;
    vs->new_start = 1;
    vs->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;
        }

        vs->packets_written = 0;
        vs->init_range_length = 0;
        vs->fmp4_init_mode = !byterange_mode;
        set_http_options(s, &options, hls);
        if ((ret = avio_open_dyn_buf(&oc->pb)) < 0)
            return ret;

        ret = hlsenc_io_open(s, &vs->out, vs->base_output_dirname, &options);
        av_dict_free(&options);
        if (ret < 0) {
            av_log(s, AV_LOG_ERROR, "Failed to open segment '%s'\n", vs->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,
                                      VariantStream *vs, HLSSegment *en,
                                      double duration, int64_t pos, int64_t size)
{
    if ((hls->flags & (HLS_SECOND_LEVEL_SEGMENT_SIZE | HLS_SECOND_LEVEL_SEGMENT_DURATION)) &&
        strlen(vs->current_segment_final_filename_fmt)) {
        av_strlcpy(vs->avf->filename, vs->current_segment_final_filename_fmt, sizeof(vs->avf->filename));
        if (hls->flags & HLS_SECOND_LEVEL_SEGMENT_SIZE) {
            char * filename = av_strdup(vs->avf->filename);  // %%s will be %s after strftime
            if (!filename) {
                av_free(en);
                return AVERROR(ENOMEM);
            }
            if (replace_int_data_in_filename(vs->avf->filename, sizeof(vs->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(vs->avf->filename);  // %%t will be %t after strftime
            if (!filename) {
                av_free(en);
                return AVERROR(ENOMEM);
            }
            if (replace_int_data_in_filename(vs->avf->filename, sizeof(vs->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, VariantStream *vs)
{
    const char *proto = avio_find_protocol_name(vs->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, VariantStream *vs, char *old_filename) {
    if ((hls->flags & (HLS_SECOND_LEVEL_SEGMENT_SIZE | HLS_SECOND_LEVEL_SEGMENT_DURATION)) &&
        strlen(vs->current_segment_final_filename_fmt)) {
        ff_rename(old_filename, vs->avf->filename, hls);
    }
}

static int sls_flag_use_localtime_filename(AVFormatContext *oc, HLSContext *c, VariantStream *vs)
{
    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 ? vs->sequence % c->wrap : vs->sequence) < 1) {
#else
            filename, 'd', vs->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(vs->current_segment_final_filename_fmt, oc->filename,
                   sizeof(vs->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,
                              VariantStream *vs, 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, vs, en, duration, pos, size);
    if (ret < 0) {
        return ret;
    }

    filename = av_basename(vs->avf->filename);

    if (hls->use_localtime_mkdir) {
        filename = vs->avf->filename;
    }
    if ((find_segment_by_filename(vs->segments, filename) || find_segment_by_filename(vs->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(vs->has_subtitle)
        av_strlcpy(en->sub_filename, av_basename(vs->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 (vs->discontinuity) {
        en->discont = 1;
        vs->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 (!vs->segments)
        vs->segments = en;
    else
        vs->last_segment->next = en;

    vs->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 && vs->nb_entries >= hls->max_nb_segments) {
        en = vs->segments;
        vs->initial_prog_date_time += en->duration;
        vs->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 = vs->old_segments;
            vs->old_segments = en;
            if ((ret = hls_delete_old_segments(s, hls, vs)) < 0)
                return ret;
        } else
            av_free(en);
    } else
        vs->nb_entries++;

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

    return 0;
}

static int parse_playlist(AVFormatContext *s, const char *url, VariantStream *vs)
{
    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")) {