I found this website that gives a detailed walk through of a complete (including ffmpeg) installation of OpenCV 2.3.1. I've tried it on Bot 119 and it works fine. The sample codes and the diagnostic codes compile and work. However, step 2 on this site does not work, so after doing step 1, do steps 2 and 3 on this site, then go back and continue on from step 3 from the original one.
If you get an issue where the resolution of the image returned by the camera is very low, you can fix it by putting in the following two lines after you initialize your CvCapture* object in your code:
A working example can be found in the camCapture code in the diagnosticCode folder of robot110.