Ok I'm about to make a fool of myself as this is probably totally obvious but here goes!

I recorded a video clip and its PAL 16:9 aspect ratio. Its also 720x576. This is where I'm lost - 720x576 isn't a 16:9 ratio. Or is it? I want to encode it to mp4 and resize it but I'm unsure what to divide my numbers by.

Sorry for sounding a bit thick!