Back to Frame Count

How frame-counting works

/frame-count is a frame-precise marker tool for competition footage or your own recordings. Load an mp4 / mov, mark the start and end frame of each solve on the timeline, and it auto-computes timings to compare against the official clock — useful for judge appeals, hand-speed analysis, and reviewing multi-solve recordings.

Core idea

Decoding uses WebCodecs (native hardware decode, near-zero overhead). True frame rate is extracted via mediainfo.js for some mp4 containers; ffmpeg.wasm provides transcoding fallback for unsupported codecs. All processing is local — your video never uploads.

How to use

1
Load a video
Drag onto the page, click the toolbar "Open video", or pick from an OBS recording folder (mp4 / mov / webm). After loading, the real frame rate appears in the top-right.
2
Mark frames
Space toggles play/pause; `,` and `.` step back/forward one frame; `M` drops a mark at the current frame. A solve needs two marks (start + end), and they're visually linked with a colored band.
3
Refine and crop
After selecting a mark, fine-tune to the exact frame with arrow keys; long-press the timeline to scrub fast. Crop mode (C) restricts the visible area to just the cube zone, hiding distractions.
4
Export
Export to CSV (one row per solve: start frame, end frame, frame count, seconds). You can also copy a "per-solve timing list" to clipboard — handy for appeal emails or side-by-side comparisons with timer logs.

Shortcuts

The toolbar's keyboard button lists the full shortcut table (playback, marking, jumping, zoom). Shortcuts work on desktop and mobile; mobile additionally supports long-press timeline drag.

See also