I came here to see if anyone had requested introducing optical flow to fix frame rate issues that sometimes occur when capturing to video (especially when shooting 4K video on mobile devices). For the most part, my Galaxy S21 can record smooth 30fps video clips at 4K, but I do still get a frames that appear to stutter / double up when I step through them on the timeline.

Basically this option would use the clip's captured frame rate (or one set by interpret footage) to step through the frames, identify where there have been no visual changes, and then attempt to use optical flow to interpolate the motion between the frames that do change. I proposed this feature request in the Rush section as well, but figure that optical flow might be a tad too expensive for most mobile devices.

Note that this feature really needs to be applied ahead of any attempt to stabilize motion using an effect on the timeline...those doubled-up frames really mess with the warp stabilizer.

I have sort of been able to achieve this "fix" by cutting two frame clips and using speed (of 50%) with optical flow enabled to force an interpolated frame between the two frames, but obviously this can be a tedious process on a long clip with random dropped frames. I then create a sequence from the fixed sequence to which I apply the warp stabilizer. Makes a huge difference.