A video-based analysis system for reflection high-energy electron diffraction (RHEED) is described which simultaneously measures the intensities and profiles of multiple diffraction beams. This system is used to record real-time RHEED intensity oscillations for layer-by-layer epitaxial growth. Fast Fourier transform analysis of the oscillation data is used to directly determine the growth rate and to accurately obtain phase information about the oscillations. This system is demonstrated and compared to other methods of recording RHEED oscillation data.