DE2 Video Examples- Interlaced video handling?

Hello!

I just started working on the examples in the University Program. When I take a look at "Example_4_Video_In", I can see the incoming images (720*244 or 720*243) being clipped at 640*240, before being scaled down to 320*240.

Can someone explain how the interlaced video stream is being handled? Are the even or the odd frames just dropped? Or are both field handled as normal "progressive" images?