Deinterlacing in Handbrake!
I have to admit that I think Handbrake is really one of the most useful freeware available for the Mac. I think it is even better and more polished than many commercial applications. The presets included with Handbrake are perfect most of the time, but it happens that the source DVD is interlaced. Handbrake thankfully includes a deinterlacing feature, but it does slowdown the process and not all the source DVDs are interlaced. What I started doing was checking out the one frame preview that you get when you click on "Picture Settings..." and I only enabled deinterlacing when there was interlacing issues. It did happened that it was interlaced and it wasn't visible on the preview frame. The solution is that Handbrake lets you check out up to ten frames. You can switch the preview to another frame in the "Picture Settings..." by clicking on "Next" or "Previous". About what speed of deinterlace you choose, that depends on whether you intend to keep the final result for a while. I tried all Fast, Slow and Slowest, but I didn't really see a difference in quality that makes it worth the extra time for me. I usually get between 50-60 frames per second at Fast and around 5-6 frames per second at Slowest (Quad Mac Pro). No Deinterlace is about 10% faster.