thumbnail: Full URL to a video thumbnail image.
description: One-line video description.
uploader: Full name of the video uploader.
+ upload_timestamp:UNIX timestamp of the upload moment.
upload_date: Video upload date (YYYYMMDD).
+ If not explicitly set, calculated from update_timestamp.
uploader_id: Nickname or id of the video uploader.
location: Physical location of the video.
subtitles: The subtitle file contents as a dictionary in the format