Smooth / interlace is an iMovie plug-in that provides two ways to ease the 'jerkiness' problems encountered when slowing down a clip, and when playing digital video (i.e. a clip edited with iMovie) on analog equipment (e.g. a TV).
One of the problems with analog video is that it sometimes (depending on age and price of the device) is not equipped to play back the full quality a digital source provides. The most common problem with analog play-back is when a digital clip is slowed down, and then (via DVD or tape) played on an analog TV. The clip becomes noticeably jerky on the analog equipment. This plug-in helps solving the problem by providing means to smooth and re-interlace the clip. The resulting clip may not look as good on digital equipment, but may look remarkably better on analog TV.
Another problems appears when a digital clip is slowed down by a large amount. Even on digital equipment the footage may become noticeably jerky. By providing a digital 'smooth' (which, in effect is a blend algorithm) processor, the apparent jerkiness can be reduced, making the result look much more professional.
The plug-in provides two separate processors that can be combined (in a single pass) for even better results:
* smoothing (through blending two successive frames). You control the amount of blending from 0% to 50%. this processor should be used when a digital play-back device exhibits the 'jerkiness' problem. * interlacing (a technique from analog TV in which half of the next frame is intertwined with the current one). Use this effect when the clip looks bad on analog equipment, but well on digital. * smooth interlace (interlace as above, but the interlaced picture is blended with the current picture -- this is a compromise solution if you need to produce the same source for both analog and digital play-back equipment). You control the amount of blending from 0-100%
As always, the smoothing/interlacing can be restricted to only part of the clip, making it easy to preserve the quality of surrounding, unmoving scenery.
What should I use it for? Use it whenever you slowed down a clip and it exhibits jerkiness, and/or when played back on analog equipment.