@ ChibiMAK

I've extensively tested the script (with some variations). Although it is extremely effective at reducing aliasing, there are a number of downsides to this method:

1) The detail is significantly reduced by halving the vertical resolution. It isn't as bad as you might expect, especially with sharpening, but the difference is certainly noticable.

2) Details appear and disappear between different frames. This leads to artifacts in the video, that are worsened by the sharpening applied to compensate for the loss of detail.

So, I suppose some might take those artifacts and the loss of detail for granted. However, I choose to keep as much of the detail intact, and avoid new artifacts.

There is a promising new way of antialiasing called "Subpixel Morphological Antialiasing". Sadly, it is not available for Virtualdub or Avisynth.