I sometimes see one blended/ghosted frame exactly at a hard cut. The sources are a mix of 29.97, 30 and 60 fps MP4, and there is no transition on the cut. Can interpolation create a phantom frame by itself?
Yes. Optical flow or frame blending can synthesize/blend frames whenever source cadence does not match the timeline, even without a visible transition.
Color & tone mapping
Switch interpolation temporarily to frame sampling and export the same cut. If the ghost disappears, you have isolated the cause.
Be explicit about 60 fps clips: normal-speed placement on a 30 fps timeline is different from interpreting 60 as 30 for half-speed slow motion. Accidental retiming plus interpolation is a common source of artifacts.
Action Video Lab Editorial Team