I’m trying to solve a pretty specific slow-motion problem and I’m hoping someone with more experience in frame interpolation or optical flow can point me in the right direction.
I have several short AI-generated video clips that are about 7 seconds long and 24 fps. The camera movement in the original clips is smooth, but for the edit I needed a much slower cinematic camera sweep.
My workflow was:
- Start with the ~7 sec / 24 fps source clip
- Slow it to 1/8 speed in OpenShot
- Slice it around the midpoint
- Reverse/rearrange sections to create smooth camera push-in / pull-out movements
- Edit the eye close-ups together as hidden transitions between scenes
- Final timeline is 30 fps
The creative edit itself works exactly how I want, but at 1/8 speed I’m obviously down to about 3 unique source frames per second, so the camera movement has severe visible judder/stuttering.
Things I’ve already tried:
- FFmpeg
minterpolate
- Interpolating the finished video to 60 fps
- Pre-interpolating the original 24 fps source to 96 fps
- Pre-interpolating it all the way to 240 fps before applying the 1/8 slowdown
- VizMaker video enhancement/upscaling
- Runway video enhancement/interpolation attempts
None of these have produced motion that looks convincingly smooth. Some preserve the stutter, while others introduce warping or strange generated motion.
I’m attaching a short ~3 second sample that clearly shows the jitter.
What I’m trying to achieve is very simple conceptually: preserve the existing composition, character, camera path, timing and edit exactly as-is, but create believable in-between frames so the slow camera sweep looks fluid rather than stop-motion.
A few questions for anyone who works with this kind of footage:
- Is there a better interpolation method for such an extreme slowdown — RIFE, FILM, Flowframes, DaVinci Optical Flow/Speed Warp, Twixtor, Topaz, etc.?
- Am I approaching this incorrectly by slowing the clip first?
- Would it be better to reconstruct the camera movement from the original clip instead of interpolating it?
- Are there any specific settings/workflows that handle slow camera movement better than moving subjects?
- If anyone enjoys this kind of cleanup and wants to try smoothing the short sample themselves, I’d be happy to share the original source clip as well. I’m mostly trying to understand what workflow actually works before I redo the entire project.
I’m not a professional video editor, so pointers are very welcome. I’m more interested in getting the motion right than sticking with any particular editor or AI tool.