1) Download appropriate video codecs.
I use
http://cccp-project.net/ for my codecs - it's open source, updated frequently, and contains most of the major codecs. If you already have XviD, a lower DivX, or the codec pack from ffdshow-tryout (at
http://ffdshow-tryout.sourceforge.net/) those will all work fine.
2) Download virtualdub, or virtualdub-mod
URL for download is:
http://www.virtualdub.org/3) Load your videos into virtualdub
File -> Open -> Select the first FRAPS video. File -> Append -> open 2nd FRAPS video. Repeat for all videos to compress.
4) Render!
Video -> Full Processing Mode. Make sure this is enabled.
Video -> Compression. Select 'ffdshow Video Codec'. Click 'Configure'.
The encoder should already be set to 'MPEG-4'. Set the 'Mode' to "One pass - quality", for simplicity. Set the quality to around 90% or so. Higher quality == bigger file size, and we don't want to go crazy here.
Hit 'ok' twice.
File -> Save as Avi. Pick a filename, and let it do the work. Once it finishes, open the video to test for frame rate, playback, etc.
-j