DVO Brickwall is a high-frequency filter that helps clean up compression artifacts doing pre-processing of the file to improve the compressed master. This means that compression artifacts can be reduced and the quality of the compressed image can usually be greatly improved. It can also help with problems with Moire patterns.

If you have interlaced footage, use the checkbox to select that type of image. 

The plugin has a Filter type parameter that affects certain types of artifacts differently, along with a Cut Off option separated into Horizontal and Vertical sliders. The Diagonal Filter, for example, can help you with DCT algorithm when mastering to MPEG files. 

Cutoff lets you control the horizontal and vertical filtering of the luminance, as a percentage of the maximum bandwidth. A setting of 100% equals a full bypass.

The rectangular Sharp filter has a very sharp cutoff, so you can use the separate settings to further adjust the filtering, with a Filter size option and a sharpness parameter.