Though it is difficult to customize video effects in Windows Movie Maker, it does allow you to exponentially speed up or slow down video clips.
The speed of a video clip is an important thing to be able to alter and Windows Movie Maker attempts to make this easy by putting the function to speed up and slow down video under the Video Effects heading. With these you can add Speed Up, Double or Slow Down, Half to your video clip to give a base amount of speed change. These are very obvious video effects that have a dramatic effect on the clips in your Windows Movie Maker project. Unfortunately in its quest toward simplicity, Windows Movie Maker has limited the control over your video effects. Conventionally you have the ability to alter the intensity and specific characteristics of a video effect when it is on a video clip. You are unable to complete this task in Windows Movie Maker and instead have to either add the video effect in full strength or leave it off. One thing that Windows Movie Maker does let you do is exponentially double the speed of the video clip or slow it down by half at a time.
Speed It Up and Slow It Down
If you want to slow down a video clip more than half you have an option to do so. When you are in the Video Effects window go ahead and find Slow Down, Half and add it to the right hand column, which adds it to the clip. Instead of just finding Slow Down, Half and adding it once, you can begin to add it several times. What happens here is that each Slow Down, Half that is added will then slow down the video speed by another half. If one Slow Down, Half will turn an eight second video clip into a sixteen second video clip then two will turn it into a thirty two second clip and three will turn it into a sixty four second clip. Likewise, Speed Up, Double will do the same thing in reverse. When you are in the Windows Movie Maker Video Effects menu just add Speed Up, Double as many times as you want to multiply the speed by double and it will do that. It does this by using an exponent formula for speeding up the clip. One Speed Up, Double multiplies the clip speed by two, a second will multiply the product of the first equation by two, and three will multiply the product of the last calculations by two again. Though this adds a certain amount of customization, you still cannot work backwards and lessen the degree of the base Slow Down or Speed Up.