Splitting long clips at every cut in Video by Zaweba

Long clips that already contain cuts are awkward to work with. A recorded programme, an old edit you only have as one file, a compilation of clips someone stitched together: each arrives as one long piece, and finding the boundaries by hand means scrubbing through and pressing the razor at every change. Video by Zaweba can do that for you with scene-cut detection.

What it does

Scene-cut detection looks through a clip, finds the cuts in it, and splits the clip at each one. It uses FFmpeg's scene score, a measure of how much the picture changes from one frame to the next. A hard cut from one shot to another is a big change, and that is what it finds.

The result is a row of separate clips on the timeline, one per shot, in the original order. Each one can then be trimmed, moved, deleted, graded or given effects of its own.

Jobs it helps with

Taking apart a recorded programme is the obvious one. If you have a recording and want to pull out a few moments, splitting it at every cut gives you the shots as separate pieces. Delete what you do not need, and you are left with the parts that matter.

Reworking an old edit is another. Maybe the original project is lost and all that remains is the exported file. Splitting it at the cuts gives you something close to the original timeline, which you can rearrange, shorten or regrade.

Compilations work the same way. A file of clips joined end to end becomes the individual clips again, ready to be put in a new order or mixed with fresh material.

It also helps when you need to grade shot by shot. A grade suited to one shot rarely suits the next, and once the clip is split, each shot can have its own correction.

Checking the splits

Run it on a clip that is on the timeline, then play through the result. Watch for two kinds of slip. A missed cut usually happens on a dissolve or a fade, where the picture changes gradually rather than all at once, because the scene score is looking for sudden changes. Fix those by hand with the razor. An extra cut can happen in a shot with a sudden flash, a quick pan or a lot of fast movement, where the picture changes sharply without a real cut. Join those back up; if the two halves are the same continuous clip, they show as through edits, and Edit > Heal through edits puts them back together.

On most material the detection gets the large majority right, and fixing a handful of exceptions is much quicker than finding every cut yourself.

What happens afterwards

Once split, the shots are normal clips. You can use the trim tools on them, disable the ones you are unsure about with Shift+E, or select a run of them and nest them into a timeline of their own to keep a long section tidy. Paste attributes is handy for applying a correction across many shots in one go.

If you want to keep the split shots as a library rather than an edit, select them and use markers or label colours to sort them, or bring the ones you like into a fresh timeline in the same project.

A reminder about the source

Splitting a clip does not change the file on your disk. Video by Zaweba only ever reads your originals, and the split happens on the timeline only. You can always bring the whole file in again if you need to start over.

Scene-cut detection is one of those tools you do not need often. When you do need it, it saves a dull hour of scrubbing and clicking, and it turns a single long file into something you can actually edit.