digital video recorder and cpu(s) questions

[paulzebo]

I'm building a digital video recorder for a home security system. The capture card is rated at 120 frames per second and runs four 480 tv line color cameras, which can be stored in several different formats. My question is, what's the best processor(s) for this application? Since the system needs to convert the video over to a motion jpeg, wavelet, MPEG4 or other format, I would think it needs somer raw CPU power. One or two CPU's? AMD or Intel Xeon/P4? I've read theres not much to gain from dual CPUs. For this application would that still be true? Ideas are welcome.