There are many packages available that can be used to encode MPEG-2 video. The simple answer is that you need a package capable of creating an MPEG-2 Program Stream from whatever source you can provide. Some examples of sources might be an uncompressed AVI or Quicktime video.
A Program Stream contains an Elementary Video Stream and an Elementary Audio Stream.
TMPG is a fairly inexpensive tool to encode video. An application note on using this software can be found on our website here:
http://www.alcorn.com/library/appnotes/TMPGEncoding/index.html
Another piece of software we frequently recommend is Main Concept MPEG Encoder. This software makes good quality MPEG2 content, and is relatively inexpensive. It also has versions that run on both Mac and PC. http://www.mainconcept.com
Please note that some versions of Final Cut Pro do not have the ability to generate program streams. In this case, additional software (such as Main Concept) may be required to produce the final stream.
More specific encoding parameters can be found here:
http://www.alcorn.com/kb/questions/187/