- `filesize`: The number of bytes, if known in advance
- `filesize_approx`: An estimate for the number of bytes
- `protocol`: The protocol that will be used for the actual download
+ - `extractor`: Name of the extractor
+ - `extractor_key`: Key name of the extractor
- `epoch`: Unix epoch when creating the file
- `autonumber`: Five-digit number that will be increased with each download, starting at zero
- `playlist`: Name or id of the playlist that contains the video