Virtual TTR | Measure toss angle and height from a video

Measures the toss angle and height from a video of a serve automatically.

Demo clip

F0 · 0.000s

Analyze a video

Choose video

Analysis starts as soon as you choose a video. Videos up to 10 seconds and 100 MB are supported; a clip with several serves is fine. The video is processed on this device only and is never uploaded.

Result

--tilt from vertical

Angle check: --
Correction: --
Toss height: ----
Rise time: --
Capture speed: --
Confidence: --

When detection fails

Use "◀ 1 frame" / "1 frame ▶" to find a frame where the ball is clearly visible.
Press "Tap to track". A prompt appears just above the video.
Tap the center of the ball once in the video. The frames before and after are tracked automatically.
If it is still off, press "Mark by hand" and tap the center of the ball on the release frame and on the apex frame.

Filming tips and how the rules are applied

Fix the camera on a tripod. Any direction works: side, diagonal or behind. When the four corners of the table are in frame, the camera's downward tilt, roll and depth foreshortening are corrected, and the height is scaled from the table's real size.
Keep the hand and the top of the toss in frame. A plain background that contrasts with the ball (a dark background for a white ball) gives the best accuracy.
Slow-motion mode on a phone (120 or 240 fps) is recommended. The slow-motion factor is estimated automatically.
When the table corners are not in frame, the vertical axis of the frame is treated as "vertical", so hold the camera level. Shooting from above makes the angle slightly larger (about 1° for a 15° downward tilt). The cm scale comes from how the ball falls (gravity).
The angle shown is the angle as seen from the camera. A lean toward or away from the camera cannot be measured with a single camera, so the true angle is equal to or larger than the one shown. A side view hides the lean across the table, a view from behind hides the lean along it. For a definitive value, film from the side and from behind and take the larger angle.
The rules require a near-vertical toss that rises at least 16 cm after leaving the palm. The rules give no number for the angle; this tool flags 30° or more.
Whether the palm is open or the ball is hidden is not checked. This is a simple measurement for practice and coaching, not an official ruling.