Thanks everyone...
For anyone interested, Aviutl is a Windows only program that can run under wine (with a few limitations). It was originally a Japanese program that was converted to English by a guy called MaverickTSE. It doesn't look like much when you first open it, but it is extremely capable, if you can figure out how to use it.
I recommend the Aviutl v1.10 ExtraPack (Win7) because it's self contained:
https://www.videohelp.com/download/AviU ... Release.7zThe above Sand animation is just a simple filter, but here is another more complex example along with a tutorial I made a few years ago:
Example video (Leaves_1080p.mp4):
https://forum.videohelp.com/attachments ... _1080p.mp4Tutorial for Leaves (Leaves_Tut.mp4:
https://forum.videohelp.com/attachments ... af_Tut.mp4