By default, Smacker will use one second of the toughest segment of frames in a video. This option is only useful when you have a tough animation to playback. The default that Smacker uses will almost always be the best choice. You can use a negative number to scale. For example, -2 would mean play back the movie twice as large.
Negative one means fill the entire the screen.
Interlaced mode is much faster than doubled mode, but it requires blit acceleration and DirectDraw. Smoothed also requires blit acceleration and DirectDraw, and Smacker must generate quite a bit of data on palette changes, so you shouldn't use smoothing on videos with many palettes. This option is usually used with a Smacker file was created with height compression during Smacking. It allows you to experiment with the different height scaling options at run-time. You can also force the window to always remain on top.