BF works by rendering intermediate frames between existing frames using a process called motion interpolation. Given two existing frames, A and B, this program can generate frames C.1, C.2...C.n positioned between the two. In contrast to other tools that can only blend or dupe frames, this program warps pixels based on motion to generate new ones. In these examples, BF slowed a 1sec video down by 10x. An additional 270 frames were interpolated from 30 original source frames giving the video a smooth feel during playback. The same video was slowed down with FFmpeg alone, but because it dupes frames and can't interpolate new ones, the video has a noticeable stutter (shown on the right-hand side).