1-2. Define keypoints and label frames

1. Define keypoints

Name the body parts you want to track (beak, left leg, …) and, if there is more than one animal, the individuals. Tick Static beside a landmark that never moves, such as an arena corner: label it once and it is on every frame.

2. Label & Edit

1. Arm Sequential and click the video once per keypoint. Each click places the active keypoint and moves on to the next one. Tab skips a keypoint you cannot see, 1–9 switch individual, Backspace deletes, Ctrl+Z undoes.

2. Press N to jump to the next suggested frame and repeat. Labelling every frame is wasted effort — neighbouring frames look the same — so aim for the default 10 % of frames, roughly every 10th.

3. Loop is the other way round: one keypoint, swept across frames. Use it to fix a single body part the fill keeps losing.

A solid marker is your label; a hollow one is a prediction. Click a hollow marker to accept it, drag it to correct it.

Tick Lock to pan and zoom without placing points. Switching to another tab locks the pointer for you.

Which frames to label

Method	Use it
Evenly spaced	first pass on any clip
Biggest pixel change	the animal moves fast and the fill cuts corners
Most different frames	long clips where the scene changes
Lowest fill confidence	after a fill — see 6. The correction loop