Tool panel: All controls are in the floating panel. Drag its title bar to move it off the part of the video you're studying. Click – (or double-click the title bar) to collapse it. Its position is remembered.
Video size: The video fills the window as large as possible while keeping its original shape. Click ⛶ for full screen (press Esc to exit).
Load Video: Click "Load Video" or drag a file onto the video area. The tool briefly plays the start of the clip (muted) to detect its frame rate.
Video FPS: The file's frame rate (usually 30 or 60). It is filled in automatically; correct it if needed. This makes each step exactly one frame.
Rec FPS: The actual camera speed (e.g., 240 fps for slow motion). This is used to calculate real time. For normal-speed video, set it equal to Video FPS.
Navigation: Use the Left/Right Arrow Keys to move one frame (hold Shift for 10 frames), or the −10 / ◀ / ▶ / +10 buttons.
Set t = 0 here: Makes the current frame time zero (e.g., the moment of release or impact). Times before it are negative. "Reset t0" goes back to the start of the video.
Playback: Use the play/pause button and seek bar. Check Loop to replay automatically.
Overlays: Drag the on-video Frame # and Time boxes (mouse or finger) anywhere on the video; their positions are used in captured images.
Capture & Save:
Capture Frame adds the current frame to the Captures list below the video.
Capture & Save also downloads it as a PNG.
Options: Full res (otherwise capped at 1280 px), Stamp (corner box), and Overlays choose what is drawn on captures. The tool panel is never captured.
View captures scrolls down to them; Back to video returns.
Each capture has its own Crop, Save, and Delete buttons.
Crop & Save: Click Crop, adjust the blue box, then click Download crop or double-click inside the box.
If a video won't play: iPhone videos are often HEVC (H.265). Chrome plays HEVC only with hardware support; Edge on Windows needs Microsoft's "HEVC Video Extensions". Converting the clip to H.264 MP4, or setting the iPhone camera to "Most Compatible", always works.
Several downloads: Your browser may ask once whether this page may download multiple files. Choose "Allow".
Designed by Professor Fedel (FrugalProf) for High-Speed Video Analysis.
Captures
No captures yet. Use Capture Frame in the tool panel.