In the situation depicted, are you allowed to drive onto the railway crossing?

Why?

The video shows the barriers rising, but the red signal still prohibits entry. Wait until the barriers are fully raised and the red lights have gone out, then check that it is safe to cross before moving.

Art. 28 ust. 3 pkt 1 Prawa o ruchu drogowym; § 98 ust. 5 rozporządzenia w sprawie znaków i sygnałów drogowych