Decide the frame rate before you import anything

The ten minutes that save an afternoon

Before a single clip is imported, four decisions:

1. Frame rate. 24 for anything meant to read as film. 25 for PAL-region broadcast. 30 for most social platforms. 60 only if the content is fast and the platform supports it.
2. Resolution. Match your delivery, not your source. 1080p is almost always right; 4K only if somebody has asked for it and paid for it.
3. Aspect ratio. 16:9, 9:16, or 1:1. This was decided when you made the stills.
4. Colour management. Leave it off unless you know you need it. A simple Rec.709 project is correct for almost all of this work, and colour-managed workflows introduce problems that are only worth solving on a graded film.

In DaVinci Resolve these live in Project Settings, and changing the frame rate after media is on the timeline ranges from awkward to blocked depending on version. Set it first.

What happens when rates do not match

A 30fps clip on a 24fps timeline has to lose one frame in five. A 24fps clip on a 30fps timeline has to repeat one frame in four.

On a static shot nobody notices. On a slow pan it is a visible stutter (the motion advances, pauses, advances) and once you have seen it you cannot stop seeing it. The name for this is judder and it is the most common technical fault in amateur edits.

Generative video makes it likely, because models output at different native rates and you will be mixing several models in one project. Check every clip’s rate on import.

# what am I actually dealing with
ffprobe -v error -select_streams v:0 \
  -show_entries stream=r_frame_rate,width,height,duration \
  -of default=noprint_wrappers=1 shot.mp4

Conforming properly

If a clip is at the wrong rate, do not let the timeline drop frames. Convert it deliberately, with one of three methods, in ascending order of quality:

• Duplicate or drop frames. What the timeline does by default. Fast, judders.
• Frame blending. Blends adjacent frames into the intermediate ones. Soft on fast motion, smooth on slow motion, and generally the safe default.
• Optical flow. Estimates motion and warps pixels. Best result, and it produces the occlusion-boundary halos from the interpolation lesson. Resolve’s free tier includes it; set it per clip in the inspector.

# conform 30 to 24 with blending
ffmpeg -i in.mp4 -filter:v "minterpolate=fps=24:mi_mode=blend" -c:a copy out.mp4

Choose per clip rather than globally. A static shot can be dropped frames with no cost; a slow pan needs flow.

Resolution and scaling

Mixing 720p and 1080p generations on one timeline is normal. What matters is where the scaling happens.

Scale up once, at the end, on the finished cut, not per clip. Upscaling thirty clips individually gives you thirty slightly different sharpening signatures, and the difference between them is visible at the cuts.

And upscaling adds no information. It invents plausible detail. A 720p generation upscaled to 4K is a 720p generation with a 4K file size and an opinion about what the missing pixels looked like. Deliver at the resolution you generated unless somebody has a specific reason.

Odd durations and proxies

Generated clips arrive at 5.1 or 4.8 seconds because latent frames divided by frame rate does not land round. Nothing is wrong; trim to what you need.

If your machine struggles with playback, generate proxies: low-resolution copies the editor uses for editing and swaps for the originals at export. Resolve does this automatically; FFmpeg does it in a loop:

for f in *.mp4; do ffmpeg -i "$f" -vf scale=640:-2 -c:v libx264 -crf 28 "proxy_$f"; done

This is the single most effective thing you can do to make an old laptop usable for editing, and it costs disk space rather than money.

The folder structure that survives

Set it up before you import, not when it hurts:

edit/
  project.drp            # or .kdenlive, .mlt
  footage/               # the generations, unmodified
  audio/
  graphics/              # titles, logos, the label card
  exports/

Never edit from your Downloads folder. Every editor stores paths to media, and a moved or renamed file becomes a missing clip, usually on the day of delivery.

Today: run ffprobe over every clip in your project and write down how many different frame rates you have. Then set the project rate and conform deliberately.