Practical Uses of Twixtor

Twixtor can be used to slow down or speed up footage by changing the frame rate of the footage. It is very accurate and will eliminate many artifacts that can occur when the frame rate changes. The objects are not torn or stretched when the speed changes. The results are excellent when using Twixtor.

This software creates new frames in a slow motion feature by interpolating and warping the original frames to create new ones. This tracking technique is new and only found in the Twixtor software. The program can be used in conjunction with many other video editing software. Here are some practical uses of Twixtor:

Color Source

The color source is important, as this is needed in order to track the clips that Twixtor is going to be used. This must have some type of value rather than none. The color information is used to create those new frames that are added to slow down the motion.

Frame Interpolation

There are 3 different ways to achieve frame interpolation. In order to blend the 2 frames, the new frame will use bi directional warping so the new frame is a combination of the 2 images. This choice is best when stretching the clips. Motion weighted blend is used to create a more softened look. If you get a pulsing effect as the sequence goes into and out of focus, then this type of blending should be used. The nearest option will take the nearest frame to make the new output frame.

Motion Vector Quality 

There are 5 different choices in order to get high quality output. No motion vectors can be calculated; ¼ resolution can be calculated and interpolated very fast for a sloppy quality. Medium quality will use the same resolution as the sloppy, but slower than sloppy for better quality. High quality uses ½ resolution and best quality interpolates at full resolution. 

Conflicting Motion

Multiple motions may occur when 2 objects pass by. These can be objects that move at different rates or different directions. This will take much longer to interpolate, but can create excellent results and the motion estimator can perform much better with conflicting motion.

Motion Blur

Motion blur can occur when speeding up film, as there is much more action happening in each frame. Motion blur will change the opening of the virtual shutter. Therefore, it is possible to choose how much motion blur should be seen in the picture. This feature only occurs when the footage is sped up.

Sequence Timing

There are a few different ways to stretch the footage. A constant stretch is used only when there is no animation. A keyframe stretch is best used when time re-sequencing is used. Stretch and speed is completely ignored when using this method. The speed of the stretch method can change and is applied to the input clip. With the speed value set, it can produce intuitive results as a constant stretch can produce unpredictable results.


Different fields are used for interlaced videos. Besides regular interpolation, field interpolation can also be used. Each field will have its own input and they need to be matched.