Shot change detection
Also known as: cut detection, shot boundary detection
Finding the points where one shot ends and another begins, which is how a long recording is broken into pieces worth judging separately.
Updated
What it means
Shot change detection locates boundaries inside a continuous file. A single forty minute recording is rarely one shot: the camera is started, pointed somewhere else, carried, mounted again, and each of those is a different piece of footage.
Finding the boundaries turns an unmanageable file into a list of candidates. Every stage afterwards works on those pieces rather than on the file, which is why it runs near the front of a pipeline.
The same job is called Scene detection when the unit of interest is a scene rather than a shot, and the difference matters mostly in how aggressively small changes are merged.
How it works in practice
Hard cuts are easy. A sudden change in colour and content between consecutive frames is unmistakable, and detecting one is closer to arithmetic than to anything learned, which is why it needs no Inference at all.
Gradual changes are harder, because a slow pan from a wall to a landscape changes everything without ever cutting. Detectors handle this with a sliding comparison rather than a frame to frame one.
A minimum shot length is a worthwhile guard. Without one, a flash of sunlight or a single corrupt frame produces two boundaries a fraction of a second apart and a fragment nothing can use, least of all Quality scoring.
What to watch out for
Action footage fires false positives constantly. Passing through a tunnel, spray hitting the lens or a rider crossing shadow all change the frame as much as a real cut does.
Camera restarts are the opposite problem. A new file often means a new shot, but the boundary sits between files and not inside one, so a detector working per file misses it entirely.
Over segmentation is the quiet failure mode. Hundreds of tiny pieces look like thoroughness and make every later stage worse, because Smart trimming cannot build a sequence out of fragments.
How RawClip handles it
Long recordings are split at genuine shot boundaries before anything is scored, so a forty minute file is judged as the dozen separate pieces of footage it really contains. A minimum length keeps a flash of sunlight from becoming a shot of its own.