Abe Pazos aka hamoid has produced a processing library that makes it very easy to export processing sketches as videos (essentially it is a wrapper for ffmpeg, so you could easily achieve more customised videos yourself, but using the library makes it quick and easy). Get the library here or from github. For JRubyArt just follow the instructions for installing the vanilla processing version, then you can ‘load the library’ in the normal way, not forgetting to ‘include_package’. For your convenience here is the basic example I have translated for you.
basic_example.rb (JRubyArt Sketch)
load_library :VideoExport include_package 'com.hamoid' # Press 'q' to finish saving the movie and exit. # In some systems, if you close your sketch by pressing ESC, # by closing the window, or by pressing STOP, the resulting # movie might be corrupted. If that happens to you, use # video_export.end_movie like you see in this example. # In some systems pressing ESC produces correct movies # and .end_movie is not necessary. attr_reader :video_export def settings size(600, 600) end def setup sketch_title 'Basic Example' @video_export = VideoExport.new(self) video_export.start_movie end def draw background(color('#224488')) rect(frame_count * frame_count % width, 0, 40, height) video_export.save_frame end def key_pressed return unless (key == 'q') video_export.end_movie exit end