FFT transform for video plugin?

Hello, does anyone know about a way to do fft transforms in a video NLE? I am looking to add solid deflickering abilities to my video editing chops and saw demos for Digital Anarchy’s filter here https://digitalanarchy.com/Flicker/main.html . Obviously not worth the $150 for me as a college student, but when looking at the demo footage of the filter in action, I saw be faint fft artifacts (not enough to be ugly, but enough to get a sense of how Digital Anarchy is using FFT under the hood). After thinking about it, an FFT would give me the tools needed to temporally blur the average luminance, as well as specific trouble spacial frequencies that would be causing flicker, with the precision needed to not have ghosting seen in simple frame blending.

I looked at the OFX implementation of the G’MIC filters, and though they do work in an OFX host like Davinci Resolve, and it does have an FFT decompose option, I couldn’t get an inverse FFT operation to work. I know there are command line options like Imagemagick that do FFT and IFFT just fine, and in batch, but all the batch rendering of image files this workflow would require would be very time prohibitive, especially given the amount of fine tuning of the frequencies temporally blurred that would be necessary to get good results. So, anyone have any suggestions?

Edit: my primary application example of FFT manipulation for video editing was video deflickering, and I am aware that often times, there are good alternatives relating to preventing flicker, such as tuning the shutter speed and frame rate to match flicker frequency, and sometimes, simple frame blending is not noticeable, however, deflicker is just an example, and there is lots of different potential uses for FFT processing in the video realm, such as complex detail and texture manipulation/generation, as well as psychadelic experimental vfx, such as blurry ghosting, and detail echos and transmutations. I don’t have a good example deflicker needing footage for purposes of community feedback, as this is more of me trying to develop video workflows while I have time to kill, before I potentially start doing some timelapse/slow mo video projects that may or may not involve tricky flicker issues, so I have a good sense of what I can and cannot do in post.

Could you provide a couple of short videos to demonstrate the flickering? There could be a number of types and causes. I won’t have the time or energy to advise on G’MIC but providing more context would help the community understand your problem better.

See my edits, deflickering is just one example of some of the applications of FFT manipulations, I also see lots of creative applications of FFT use in video, and am just trying to figure out if something exists, and if not, maybe crowdfund some money to pay for developement of an open source FFT video plugin solution or fix g’mic FFT.

FFT is a broad topic with many applications. I am unsure whether a FLOSS plugin exists. Perhaps ask the #software:natron or Blender folks.

Could you at least provide examples on how you used FFT in G’MIC or ImageMagick? Details are important; otherwise, we are just guessing.