with the "ext" entry and one of:
* "data": The subtitles file contents
* "url": A url pointing to the subtitles file
- Note: YoutubeDL.extract_info will get the requested
- format and replace the "subformats" list with it.
duration: Length of the video in seconds, as an integer.
view_count: How many users have watched the video on the platform.
like_count: Number of positive ratings of the video