Sometimes all that is left of an edit is the exported MP4. The project file is on a laptop that got wiped, or a client sends the final cut and asks for a shorter version, or a clip from last year needs one shot swapped. To re-edit it you need every shot as its own clip again, and finding the cuts by hand means scrubbing frame by frame and splitting at each one. The video editor in the osFoundry desktop app can find the cuts for you and turn each one into a split. The example below is NASA's public-domain launch highlights from the Artemis II test flight: 1 minute 32 seconds, delivered as a single file.
Put the finished video on the timeline
Open a video project and use the file icon next to Shots to add the video as a shot. The whole edit lands on the V1 track as one long clip. The minus button at the right end of the timeline zooms out until all of it is in view.
Let the editor find the cuts
Select the clip, open Presets in the left-hand rail, type "cuts" into the search box and pick Find the cuts. The preset has two settings:
Sensitivity is the threshold. The editor runs ffmpeg's scene filter over the clip, which compares each frame with the one before and gives it a score between 0 and 1. Any frame that scores above the sensitivity is a cut. The default is 0.27.
Shortest scene is a minimum gap in milliseconds, 500 by default. A dissolve or a flash can push several frames in a row over the threshold, and without the gap each of them would become its own cut. On this video the setting matters at lower sensitivities: at 0.12 the cut at 33.3 seconds fires on two consecutive frames, 33 milliseconds apart, and the gap folds them into one.
Click Apply, then the back arrow to return to the editor. On this clip the run took about a second, on the computer itself. Nothing is uploaded and no model is involved, which the result line says in its own words.
Split at each cut
Under the timeline the result reads "18 cuts found", followed by one button per cut:
Each button splits the selected clip at that time. Start with the last one, Split at 73.0s, and work back to the first. A split leaves the part before the cut on the clip you selected and puts the rest on a new clip, so going from right to left keeps every remaining cut inside the selected clip.
A split doesn't copy anything. The new clip points at the same file and simply starts reading it later, so nothing is re-encoded and no new video file is written. After 18 clicks the timeline holds 19 scenes:
From here each scene can be trimmed, moved or deleted like any other clip.
When the cut count looks wrong
Two adjustments cover most videos. If one dissolve or a burst of camera flashes shows up as a cluster of cuts, raise Shortest scene. If a cut between two similar-looking shots is missing, lower Sensitivity.
This launch video shows why the default sits where it does. Scored with ffmpeg directly, its weakest real cut, from the rocket clearing the pad to a wide shot of it in a pale sky, scores 0.34. The strongest frame that isn't a cut, the shaking camera at engine ignition, scores 0.16. Anything between those two finds exactly the 18 cuts. The value of 0.4 that's often suggested online would miss that cut, and at 0.1 the ignition alone adds two cuts that aren't there.
Detection runs on ffmpeg on your own machine, part of what the local-first page describes. The desktop app is free from the osFoundry download page for macOS, Windows and Linux.
