FFmpeg: Improved 'Rainbow-Trail' effect





* Includes sound 🔊

I have updated the script for this FFmpeg 'rainbow' effect I created in 2017¹ as there were numerous flaws, errors, and inadequacies in that earlier version. One major issue was the inability to colorkey with any colour other than black; this has been resolved.

This time, the effect is based on the 'extractplanes' filter and the alpha levels created after using a 'colorkey' filter. This produces a much more refined result; better colour shaping, and maintains most of the original foreground subject. This 'extractplanes' filter can even be removed from the filtergraph, to create an alternative, more subtle effect.