Can't Setup subtitles, need SRT format for VLC media player on Windows 11 Host Machine

[TeomanEgeSelcuk]

Issue Description:

I am unable to get subtitles to work with YoutubeDL-Material. I need the subtitles to be in SRT format as I am using a Windows 11 machine and VLC media player.

Configuration Details:

• Operating System: Windows 11
• Media Player: VLC
• Docker Configuration:

  version: "2"
  services:
    ytdl_material:
      environment: 
        ytdl_mongodb_connection_string: 'mongodb://ytdl-mongo-db:27017'
        ytdl_use_local_db: 'false'
        write_ytdl_config: 'true'
        YTDL_FORMAT: 'bestvideo[height<=1080]+bestaudio/best[height<=1080]'
        YTDL_SUBTITLES_LANG: 'en'
        YTDL_SUBTITLES_AUTO: 'true'
        YTDL_POSTPROCESSORS: '[{"key": "FFmpegSubtitlesConvertor", "format": "srt"}]'
      restart: always
      depends_on:
        - ytdl-mongo-db
      volumes:
        - ./appdata:/app/appdata
        - ./audio:/app/audio
        - ./video:/app/video
        - ./subscriptions:/app/subscriptions
        - ./users:/app/users
      ports:
        - "8998:17442"
      image: tzahi12345/youtubedl-material:latest
  
    ytdl-mongo-db:
      image: mongo:4
      logging:
        driver: "none"
      container_name: mongo-db
      restart: always
      volumes:
        - ./db/:/data/db

default.json:

{
  "YoutubeDLMaterial": {
    "Host": {
      "url": "http://example.com",
      "port": "17442"
    },
    "Downloader": {
      "path-audio": "audio/",
      "path-video": "video/",
      "default_file_output": "",
      "use_youtubedl_archive": false,
      "custom_args": "--write-sub --sub-lang en --convert-subs srt",
      "include_thumbnail": true,
      "include_metadata": true,
      "max_concurrent_downloads": 5,
      "download_rate_limit": ""
    },
    "Extra": {
      "title_top": "YoutubeDL-Material",
      "file_manager_enabled": true,
      "allow_quality_select": true,
      "download_only_mode": false,
      "force_autoplay": false,
      "enable_downloads_manager": true,
      "allow_playlist_categorization": true,
      "enable_notifications": true,
      "enable_all_notifications": true,
      "allowed_notification_types": [],
      "enable_rss_feed": false
    },
    "API": {
      "use_API_key": false,
      "API_key": "",
      "use_youtube_API": false,
      "youtube_API_key": "",
      "twitch_auto_download_chat": false,
      "use_sponsorblock_API": false,
      "generate_NFO_files": false,
      "use_ntfy_API": false,
      "ntfy_topic_URL": "",
      "use_gotify_API": false,
      "gotify_server_URL": "",
      "gotify_app_token": "",
      "use_telegram_API": false,
      "telegram_bot_token": "",
      "telegram_chat_id": "",
      "webhook_URL": "",
      "discord_webhook_URL": "",
      "slack_webhook_URL": ""
    },
    "Themes": {
      "default_theme": "default",
      "allow_theme_change": true
    },
    "Subscriptions": {
      "allow_subscriptions": true,
      "subscriptions_base_path": "subscriptions/",
      "subscriptions_check_interval": "86400",
      "redownload_fresh_uploads": false
    },
    "Users": {
      "base_path": "users/",
      "allow_registration": true,
      "auth_method": "internal",
      "ldap_config": {
        "url": "ldap://localhost:389",
        "bindDN": "cn=root",
        "bindCredentials": "secret",
        "searchBase": "ou=passport-ldapauth",
        "searchFilter": "(uid={{username}})"
      }
    },
    "Database": {
      "use_local_db": false,
      "mongodb_connection_string": "mongodb://ytdl-mongo-db:27017"
    },
    "Advanced": {
      "default_downloader": "yt-dlp",
      "use_default_downloading_agent": true,
      "custom_downloading_agent": "",
      "multi_user_mode": false,
      "allow_advanced_download": false,
      "use_cookies": false,
      "jwt_expiration": 86400,
      "logger_level": "info"
    }
  }
}

• custom_args: Added --write-sub --sub-lang en --convert-subs srt to the custom_args field under Downloader. This should ensures that subtitles are downloaded in SRT format.

I have followed all the installation instructions, and they have worked perfectly. Videos can be downloaded without any issues. However, I can't get the subtitles to work. That's the only issue I am facing.

Despite these settings, the subtitles are not being downloaded or converted to SRT format. Any help resolving this issue would be greatly appreciated.

Steps to Reproduce:

1. Set up YoutubeDL-Material using the provided docker-compose.yml.
2. Configure the default.json as shown.
3. Attempt to download a YouTube video with subtitles.

Thank you for your assistance!