After I rip a DVD into an MPEG file I want to find the aspet ratio, but it doesn't appear in the file propert

After I rip a DVD into an MPEG file I want to find the aspet ratio, but it doesn't appear in the file properties. I would be okay finding this by using a windows application, or by using a DOS/command line command or vbs script. I need to know the aspect ratio before I re-encode the file!