How to make the appearance of the object only when you scroll to a certain position?

Hello. I have the code contains the video element with YouTube -

Help please to write the script in javascript or jquery (preferably in js), which began the download of the item only when you scroll the user to the item.

I would be very grateful!
March 19th 20 at 08:52
1 answer
March 19th 20 at 08:54
For similar functionality about 3 years ago used jQuery-viewport-checker. Works flawlessly to this day.

Find more questions by tags HTMLjQueryJavaScriptCSS