Video
What is keyframe extraction?
Keyframe extraction selects representative frames — fixed rate or scene changes — so search and models run on stills instead of every encoded frame.
Updated · Part of What is a frame iterator?
How it works
- A higher rate catches shorter actions and costs more embeddings.
- A lower rate is cheaper and misses brief moments.
- The frame you keep must still know its time in the source.
What it is not
It is not indexing every compressed frame, and it is not picking a thumbnail by hand.
keyframe extraction: this, and the thing it is confused with
| This | Not this | |
|---|---|---|
| Goal | Enough stills to find the moment | Every encoded frame |
| Tradeoff | Recall versus embedding cost | A single poster frame |
| Output | Rows with timestamps | A contact sheet with no times |
Where Pixeltable fits
Pixeltable extracts those stills with a frame iterator. The rate is the fps argument, not a separate thumbnail job.
Questions
- How does keyframe extraction work?
- A higher rate catches shorter actions and costs more embeddings. A lower rate is cheaper and misses brief moments. The frame you keep must still know its time in the source.
- What is keyframe extraction often confused with?
- It is not indexing every compressed frame, and it is not picking a thumbnail by hand.