Linux nvidia graphic confirmation

I have this old laptop with intel igpu hd4400 and geforce 840m dgpu.

Do the GeForce 840m dont have hardware video decode acceleration or it have? Cos when using prime nvidia on demand the laptop can play youtube. But when select prime performance (nvidia card only) the laptop cant play youtube but can play 3d games.

When on nvidia card (prime nvidia only) there is no information on vainfo and vdpauinfo.

Using nvidia 470 driver.