This example shows a couple of different Jitter techniques. It shows how you can very simply use a MIDI control value to alter a Jitter attribute. In this case, the MIDI values from a modulation wheel (continuous controller 1), which range from 0 to 127, are divided by 127.0 to provide an xfade value from 0. to 1. to the jit.xfade object, to crossfade between two movie files.
This program assumes that you have a folder of image files (jpg, etc.) that you want to show as a slideshow. This program also assumes that those images all have the same dimensions.
The program assumes images that are 320x240 pixels. If you want to use another size, you should change the dimensions of the jit.qt.movie objects and the size of the jit.window. Images that do not have a 4:3 aspect ratio will get distorted when shown fullscreen, unless some adjustments are made.
To jump immediately to a new location in a movie, you can send the frame message to jit.movie (or jit.qt.movie). To crossfade to a new location, instead of a jump cut, you need to be playing the video twice, and crossfade from the current video to the second video, after which you can stop playing the first video. To do that again, you can just reverse the process: start the first video at the new location, crossfade back to the first video, and stop playing the second one.
You can make a crossfade between two videos or betwen two sounds by multiplying the amplitude of one of them by values going progressively from 1 to 0 while you multiply the other by values going progressively from 0 to 1. In this example, we use a slider object that outputs values from 0 to 1 to control the volume of two movie soundtracks, using the vol attribute of jit.qt.movie (or jit.movie).