I did this quite a while ago, and it wasn't easy. The file was edited using a version of virtualdub that can handle .asf files (they are still kicking around on the net), but before I can do that, I had to re-encode the file using MS windows media encoder so that the file was uncompressed (I think). Virtualdub would not read the file otherwise. There's a HOWTO on this subject somewhere on the net. Maybe there is a better way to do it these days...
