One of the things I love regarding DOSBox is being able to de-scanline FMV games using scanlines via the 4xSaL shader. It does a great job for games using the typical black line, content line approach (Privateer 2, 11th Hour, etc.). Typically this is seen in games trying to conserve on disk space by reducing the resolution of their videos in half.

The 4xSal shaders description... "The 4xSaL shader processes a gfx. surface and redraws it 4x finer." isn't too explicit. Is de-scanlining an intended purpose of that filter, or is it just happenstance?

A similar scanline technique is used in "MTV's Club Dead", and a number of scene demos (Bill G force, Guster, Tao, etc.) to render >8bit images on an 8bit display. Scene demos tend to use an approach where three vertical pixels make up a single hi-color pixel, while Club Dead uses a less common approach with a square of blue, black, red, and green pixels make up a hi-color pixel. Applying the 4xSaL filter to these doesn't work out. In the first case, since there are 3 rather than 2 scanlines, one just ends up with a different scanline pattern. In the second case, at least in Club Dead, one ends up with a display tinged red/green (though I'm not clear why, since the color distribution seems uniform within a 4x4 block).

In any case, was hoping someone might be able to post a shader (or more likely a set for different pixel configurations) to clean up the DOSBox output of these sorts of outputs.