Creating multiple video thumbnails

[ale.cdp]

Hello to everyone, I would need to make thumbnails of some videos in a folder (if there was a chance to create them by pointing to different folders to say the truth would be even better).
I think the most immediate solution is to create a batch with which to give you all the necessary information: video folder path, save folder folder location, image format, capture frame every X seconds / capture all video frames, image file name, etc. . (do I forget something?)
I have no idea how to create this batch but I know that with VLC (I have version 2.2.6) should be possible.
Could you write the code?

(I hope this translation from Italian is clear)

thank you