Frame interpolation: 30 → 60 fps
Upscaling adds pixels to each frame. Interpolation adds frames between them. They solve different problems, and you can combine them.
What it does
An interpolation model looks at two neighbouring frames, estimates how every region moved, and synthesises new in-between frames. Double the frames (2×) and 30 fps plays at 60 fps; quadruple them (4×) and play at the original rate for 4× slow motion. Well-known open models include DAIN (2019), RIFE (real-time intermediate flow estimation, ECCV 2022) and Google’s FILM (ECCV 2022), which handles large motion.
Good and bad candidates
| Footage | Interpolate? | Why |
|---|---|---|
| Gameplay, screen recordings | Yes | Smoothness is the point; motion is predictable |
| Sports, action cams | Usually | Smoother pans; check fast limbs |
| Slow motion from 30/60 fps | Yes | Classic use; 2–4× works best |
| Old film, 24 fps drama | Rarely | “Soap opera effect”; changes the look |
| Anime (often animated “on twos”) | Carefully | Held frames and smear frames confuse models |
Workflow
- Decide the goal: smoother playback (30 → 60 fps) or slow motion (interpolate 2× or 4×, then play slower).
- Check the source frame rate with the video checker, and deinterlace tape or broadcast footage first.
- Interpolate at the source resolution; it is faster, and many workflows interpolate before upscaling.
- Inspect fast motion, hands and object edges for warping, the typical interpolation artefacts.
- Upscale afterwards if you also need more resolution, then export at the new frame rate.
Free and offline: FFmpeg
minterpolate=fps=60:mi_mode=mci:mc_mode=aobmc:vsbmc=1 does motion-compensated interpolation in FFmpeg. It’s slow and less robust than AI models, but fine for simple motion. The FFmpeg generator can add it for you.
FAQ
Will 60 fps make my film look like a soap opera?
Often, yes. Interpolating 24 fps narrative footage to 60 creates the smooth “soap opera effect” many viewers dislike. Interpolation suits gameplay, sports, screen recordings, timelapses and slow motion better than drama.
Why are there warped blobs around fast-moving objects?
Interpolation models estimate motion between frames. Fast motion, occlusions (one object passing behind another) and repeating patterns confuse the estimate, and the model smears or warps pixels. Lower the multiplier, or cut around the problem shots.
Is FFmpeg’s minterpolate any good?
It’s free and works offline, and it handles slow, simple motion well. It is much slower than AI tools and produces more artefacts on complex motion. The FFmpeg generator includes it as an option.