How to create a counter for youtube videos on your website?

Question

YouTube

Good afternoon.
Faced the task of creating a counter for youtube videos, which are located on my website.
For example, the site has 3 videos per page, and when a certain video is launched, an ajax request is made to a certain method.
I can track the very moment of starting and stopping the video, but then it's a dead end.
Reading the youtube api manual didn't help.
Here is the jsfiddle code .

Answer 1

1. At the start of the video, we record the start time.
2. When you stop the video - see how much has passed since the start.
3. If more than n seconds - send ajax to the php script to increase the value.
Actually purely on js in any way by itself.
Unless individually for each user in LocaleStorage / cookies / similar (it will be stored only until the cache is cleared).
Or do you need something radically different?
The question is not clear.