Video Motion Tracker
Choose a distinct point on the first sampled frame. Local RGB patch matching follows it through a short video. Review orange warnings at occlusions or scene cuts, click or enter a corrected position, and export the trajectory with timestamps, coordinate units, confidence and source hash. This is coordinate analysis, not video masking or editing.
Key features
- Track a manually selected point through up to 48 sampled frames of a short local video
- Review a trajectory overlay and time-indexed coordinate table
- Flag likely cuts, occlusions, ambiguous texture and motion beyond the search window
- Correct any frame with a click or numeric X/Y fields and resume from the correction
- Report trusted path distance and peak speed in analysis pixels
- Export CSV and JSON with source SHA-256, original-size projection and normalized coordinates
How to use
- Choose a local video up to six seconds and 32 MiB, or create the example.
- Click a textured point on the first sampled frame or enter X and Y pixels, then apply.
- Open orange timeline warnings and correct the point on the affected frame. Inspect unflagged estimates too.
- Compare the path and coordinate table; download CSV or JSON and retain the source reference.
Use cases
- Measure the rough path of a moving marker
- Export positions for an animation or research sketch
- Annotate occlusions and scene boundaries in a short demonstration
Frequently asked questions
Which coordinates are in the files?
X and Y are pixel-center coordinates measured from the top-left of the resized analysis frame. The source_x/source_y columns scale them back to the original dimensions approximately; normalized values are fractions of analysis width and height. Every row has a requested sample-midpoint time in seconds and the source SHA-256 identifies the input bytes.
Are confidence scores probabilities?
No. They are heuristic numbers based on patch error and texture, not calibrated probabilities. Scene cuts, occlusions, repeated patterns, camera motion or large jumps can fool the tracker. Correct and review the coordinates before scientific use.
Does it track a person automatically or alter the video?
No. You choose one visible point. The tool exports coordinates only. The privacy masker instead tracks a box and creates a masked video.
Why are warnings shown?
A frame-wide color change suggests a cut; a poor local patch match suggests occlusion or changed appearance. A flat or repeated patch is ambiguous. The last trusted point is held until you correct a frame or matching recovers.
What are the file limits?
One local MP4/MOV or WebM/MKV container up to 32 MiB and six seconds; the browser must decode its codec. Analysis samples at eight frames per second and resizes the longest edge to at most 480 pixels. It does not preserve or export audio/video.
Privacy
The video, sampled frames and coordinates remain in this browser tab. No upload or account is used. Clearing releases the media URL and frames.
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