tennis3d — Shot Labeler

New here? Labeling is a 4-step loop

Load a video (the “Video” picker, top-left). Its fps is auto-detected from the video — just confirm it in the Clip metadata panel below.
Scrub to the contact frame — the exact frame the racket meets the ball. Drag the time bar under the video to move fast, jump ±1s with ⇧←/⇧→, then fine-tune with ←/→ (±1) and ,/. (±5).
Press Enter to mark a shot at that frame.
Tag it with one key each: player 1–4, stroke q w e r …, spin 7–0, outcome u i o p … (see the cheatsheet →).

Repeat for every shot, then Export JSON and save it into labeling/labels/. Your work autosaves locally as you go. This box disappears once you load a video.

frame 0 / 0 time 0.000s speed 1.00×

Clip metadata

clip (filename)

fps

source

court_surface

notes (clip)

Active shot

advanced

Shots

0 shots

Tab / Shift+Tab to select

id	contact	player	stroke	spin	outcome

Keyboard cheatsheet

The basic loop

Scrub to contact → Enter to mark → tag player / stroke / spin / outcome → repeat → Export JSON.

Transport

Play / pauseSpace

Step ∓1 frame← →

Step ∓5 frames, .

Jump ∓1 second⇧← ⇧→

Scrub to anywheredrag bar

Speed − / +↓ ↑

Mark shot hereEnter

Stroke

forehand / backhandq w

fh / bh slicee r

fh / bh volleyt y

serve flat / kick / slicea s d

smash / drop / lobz x c

Outcome

in / out / netu i o

winnerp

forced / unforced errj k

unknownm

Player

near / far / left / right1 2 3 4

Spin

topspin / slice / flat / unknown7 8 9 0

Shot bounds & edit

set start / end frame[ ]

select prev / next shot⇧Tab Tab

delete active shot⌫ Del

More strokes (click)

half-volley, swinging volley (fh/bh), backhand overhead, underarm serve, tweener, drop/lob volley, squash shot, topspin lob — click them in the Active shot panel (no key).

Advanced (optional)

Tick advanced at the top of the Active shot panel to add detail fields: hands, direction, serve # & placement, position, depth, stance, return/approach, rally #. Off by default.

Notes