What it is good at, and what it is not
The pipeline reads speech, sound and motion, so it is strongest on long videos with people talking in them. These are the five kinds of source it handles best - each page says plainly where that kind of material has limits.
What makes a good source
The scoring leans hardest on speech. A transcript with dense, continuous talking gives the model the most to work with - it can tell a punchline from a pause, and it can find the boundaries between one thought and the next. Audio energy and motion are real signals too, but they are supporting ones: they tell you something happened, not whether it was worth keeping.
So the ranking is roughly: conversation beats monologue, monologue beats narration over footage, and anything beats a video with no speech at all. A gameplay recording with no commentary, a music video, a silent timelapse - these are the cases where there is very little for the pipeline to read, and it will produce clips that are technically correct and arbitrary.
Length helps, within your plan's ceiling. A forty-minute talk contains more candidate moments than a four-minute one, and the scoring has more to choose between.
What the reframe means for your footage
Every page here says some version of the same thing, because it is the property that decides whether this tool suits your material: the 9:16 output keeps the whole original frame, at full width, with a blurred copy of itself filling the bars above and below. Nothing is cropped.
That is why webinars, interviews and conference talks are on this list. Those are formats where the frame contains more than one thing - two people, a presenter and their slides, text across a wide shot - and a tool that crops a vertical slice out of the middle deletes half of it without telling you.
It also means a single centred talking head is rendered smaller than a cropping tool would render it. If your footage is one person in the middle of the frame and nothing else, that is the case where cropping genuinely wins.
If your source is not on this list
These five are the formats the pipeline is strongest on, not the only ones it accepts. Anything with people talking in it behaves like the closest neighbour here - a livestream VOD scores like a webinar, a sermon or a lecture like a conference talk, a video essay like a monologue podcast.
The free plan runs the entire pipeline, so the reliable way to find out is to send one real video through it rather than to reason about it from a page.