Point tracking and stabilising

Tracking finds one point of a video in every frame and turns its path into x and y keyframes. Use it to pin a label, a sticker or a graphic to something that moves, or to cancel the shake of a handheld shot.

Track a point

1. Select a video clip. A Track point section opens under the timeline bar.
2. Move the playhead to a frame where the point is easy to see, then click it on the picture. A solid box shows the feature that is matched, a dashed box how far it may move between two frames.
3. Set Feature size. Pick something with texture inside the box: a corner, a logo, a knot in wood. A flat colour cannot be tracked.
4. Press Track forward, Track backward or Track both ways.

The tracker compares the patch around your point with the next frame, on brightness only, coarse to fine, and runs in a Web Worker so the editor stays responsive. If the match falls below half, it stops and says how many frames it followed; place the point again on a later frame and track from there.

Attach it to a layer

Choose a layer in Layer, set an Offset in px if the layer should sit away from the point, and press Apply to layer. The layer gets x and y keyframes on the tracked frames, linear between them. Keys outside the tracked span are kept; keys inside it are replaced.

The video is assumed to fill the frame. Tracked positions are measured from the centre of the frame, like any other x and y.

Stabilise

Stabilise video applies the opposite of the path to the video clip itself: the tracked point stays where it was on the frame you placed it. The picture moves instead, so scale the clip up a little to hide the edges.

From the chat agent and MCP

• track_point takes clip_id, time (seconds from the clip start), x and y (px of the frame), and optionally from, to, feature and search (px). It decodes the frames on the server with ffmpeg, runs the same tracker and returns a track_id.
• apply_track takes the track_id, a target_clip_id, mode (follow or stabilise) and offset_x / offset_y.

The track is saved with the video, so apply_track works in a later call, including from the CLI. The last 20 tracks are kept.

feega motion tool <nodeId> track_point --input '{"clip_id":"abc","time":0,"x":960,"y":540}'
feega motion tool <nodeId> apply_track --input '{"track_id":"<track_id from the first call>","target_clip_id":"def","mode":"follow"}'

The server reads frames at the clip’s own pace. A clip with reverse, or with time remap keyframes, cannot be tracked there: clear the remap first. The browser tracks those clips as they play.