Does a yellow flashing signal indicate that the red signal is about to come on?

Why?

The flashing amber light in the video warns of danger or an obstruction and requires extra caution. It does not announce a red light; a steady amber light does.

§ 98 ust. 6 oraz § 95 ust. 1 pkt 2 rozporządzenia w sprawie znaków i sygnałów drogowych