Preset Config

    "outtmpl": "%(uploader)s/%(title)s.%(ext)s",
    "download_archive": "download_archive_mp4",
    "format":                   "best[ext=mp4][height<=720]/best[ext=mp4]/mp4",
    "merge_output_format":      "mp4",
    "no_warnings":              False,       # Do not print out anything for warnings.
    "restrictfilenames":        True,        # Do not allow "&" and spaces in file names
    "ignoreerrors":             True,        # Do not stop on download errors.
    "nooverwrites":             True,        # Prevent overwriting files.
    "writedescription":         True,        # Write the video description to a .description file
    "writeinfojson":            True,        # Write the video description to a .info.json file
    "writeannotations":         True,        # Write the video annotations to a .annotations.xml file
    "writethumbnail":           True,        # Write the thumbnail image to a file
    "writeautomaticsub":        True,        # Write the automatically generated subtitles to a file
    "keepvideo":                False,       # Keep the video file after post-processing
    "skip_download":            False,       # Skip the actual download of the video file
    "noplaylist":               False,       # Download single video instead of a playlist if in doubt.
    "postprocessors":          [             # A list of dictionaries, each with an entry
        {"key": "EmbedThumbnail"},           # * key:  The name of the postprocessor. See
        {"key": "FFmpegMetadata"},           # youtube_dl/postprocessor/__init__.py for a list.
        {"key": "FFmpegEmbedSubtitle"}       # as well as any further keyword arguments for the
    ],                                       # postprocessor.
    "prefer_ffmpeg":            True,                # If True, use ffmpeg instead of avconv if both are available,
                                                     # otherwise prefer avconv.
    "retries":                  999,         # Number of times to retry for HTTP error 5xx