Video Interlacing: Enemy of the peoples

I was busy ripping some episodes of The Legend of Prince Valiant (a cartoon series from the early 1990s), one of the first things I did was to check if the video was interlaced, so that I could change my settings appropriately.

You see, to reduce flicker, television shows played at standard definition transmitted a half frame at a time: your CRT television would trace half of a frame, and then the other half. This way you get a smoother picture. Often, DVDs are encoded in this manner as well, causing some funk line patterns to show up, like this:

This interlacing would look fine on a standard-resolution CRT television, but looks cruddy on modern, HDTVs. The solution is, when you are ripping it, to turn on some amount of “de-interlacing”. Typically, it will give you many options, but it is best to pick the slowest method (often this is “linear blend”), since it will look the best. Like so:

If you don’t have this option, many decent video players will let you de-interlace as you watch. For example, in VLC, you can access various de-interlacing methods from the video menu: