avisynthing is...well, doing stuff with your footage using the scripting language/frameserver avisynth. so to answer one of your questions right away, yes you will have to get another "program"...but it's free
link to avisynth (get the .exe)
avisynth can be used for a few different things (you can even make an amv using only avisynth) but most people here use it for cleaning up a video source.
there is a section in eadfag about avisynth
here, and
here
you may find
the avisynth home page helpful as well
perhaps a more extreme example of what avisynth can do (with the help of third party filters and functions...which are also free) is what I did to clean up the R1 release of Full Metal Panic? Fumoffu


this source has some of the worst dot crawl and rainbowing imaginable, and also had a few other problems. (this probably isn't as good as I could have gotten the footage to look, I've been led to/found some very wonderful filters since I did that)
it takes a while to be able to determine all of the problems that a video source has, and to know which filters (in which order) to apply to fix those problems...but in most cases, doing something is better than doing nothing.
some filters
doom9 has 2 sections in their forums that I have found very helpful for troubleshooting and finding more filters/functions
Avisynth Usage at doom9
avisynth development at doom9
that should get you well on your way, don't hesitate to ask questions