You can use ffmpegx if you are running OS X. Toast 5 will convert avi and movie files to mpeg-1, while I believe Toast 6 will convert to either mpeg-1 or mpeg-2. I use Toast 5 so I cannnot say for certain if you can create separate mpeg-1 and -2 files with Toast 6, as I have heard some people say that they can only create VCD (mpeg-1) or SVCD (mpeg-2) disks, not separate mpegs.