How video editing softwares change the FPS from ~29.87 FPS to 30 FPS. Where do the extra frames come from?

Question

How video editing softwares change the FPS from ~29.87 FPS to 30 FPS. Where do the extra frames come from?

In: 39

Answer 1

Depending on software. But they can simply interpolate one frame from two neighbouring frames every 1000 frames.

This is done for many 24 to 30 frames conversions. Every other frame gets interpolated from it’s two neighbours.