Video detect frame

I made a tour with an inline video. An action will be triggered after the video has started playing for +/- 15 sec.

onclick="hotspot[introvideo].play();
		delayedcall(15.7,set(hotspot[btn_email].visible,true));"

But this method is not reliable due to internet traffic and slower internet connections.
Therefore I was woundering if it is possible to trigger the action at a certain frame of the video?

Tnx for help,
Yvan