There is a lot about this on this and other forums like VideoHelp.com.
But to be brief, you do not need Decryptor or Shrink, you will need editing and DVD authoring software.
Both of these, at least basic versions, usualy come with capture card, check that first.
If you have NERO or ROXIO you should be able to do what you want.
Personally I use TMPGEnc Xpress for editing and DVD file formatting , than DVD Lab for DVD authoring, Nero for burning.
There are other softwares to do the job.
Lots of people recommend to get DVD VHS combo recorder, they are not that expensive any more and produce a DVD you can edit with Shrink.