It’s useful to recommend other softwares to solve an immediate problem, but I agree with kiprode that the best place to retime frame rates is within Video Enhance AI itself. The reason being that it already rewrites each frame based on a sequence from the neighboring frames. That’s the reason it does a very good job removing noise and finding details that isn’t visible in each frame. The details and pixels of each frame live within a virtual space before it’s written into the actual frame itself. Therefore the most logical place to change frame rate is within the very software that rewrites the video image data based upon a whole sequence. Sure it’s possible to get a good result with mixed framerates in Adobe Premiere or other video editing tools, but the point of Video Enhance AI is to achieve the best quality results in your video clips BEFORE further editing in other software.
There can be many reasons why you want to do this. You have some archive footage shot at one frame rate, you use another frame rate on your current camera, and you have to mix in a few stock video sequences shot in a different framerate. When you already have the ability to rewrite video frames based on information from its place within a sequence, it should also be possible to make smooth super slow motion based on that information with results matching other softwares like Twixtor. Twixtor - RE:Vision Effects If you already have to enhance some of your videos anyway, you should also be able to set your desired output frame rate directly within Video Enhance AI.
As a sidenote; One of the other reasons I use Video Enhance AI, besides the obvious noise and details, is its ability to remove compression artefacts you usually find in H.264 and other formats. You don’t see the compression initially, but if you need to modify colors or contrast significantly those compression artefacts become very visible. Video Enhance AI solve this with its ProRes 422 formats. This feature of VEAI is very helpful if you need to later use your footage in a tracking software like Lockdown or other to obtain optimal tracking results that isn’t possible with your initial archived footage. This is very well demonstrated in this video. Using the Optional Tracking Filter - YouTube
VEAI restores many otherwise lost details and should therefore also be the best place to retime footage.
Retiming frame rates by setting the desired target frame rate should be a feature in the processing queue of Video Enhance AI.