runrazor 0.2.1

RunRazor: movement-analysis tools for stationary-camera footage

RunRazor

Tools for movement analysis from stationary-camera footage.

If you film yourself or someone else repeating a course past a fixed camera -- hill repeats, sprints, drills -- RunRazor turns that raw footage into usable clips. It uses the subject's GPS track to find each pass automatically, can crop and follow the subject so they stay framed, and lets you compare runs side by side or export the cuts straight to a video editor.

Command	What it does
runrazor	The main app: automatically cut a video using the subject's GPS track, review and tune the cut points, reframe, and export (see rrdocs runrazor)
rrreframe	Crop and follow a moving subject automatically so they stay framed (see rrdocs reframe)
rrcompare	Play two runs side by side, lined up in time, to compare them (see rrdocs compare)
rrtag	Mark matching points in two runs by hand so rrcompare can line them up (see rrdocs compare)
rrdocs	Open the bundled documentation in your browser

Setup

RunRazor needs three things on your system:

• Python 3.11+ -- to install and run RunRazor
• ffmpeg (with ffprobe) on your PATH -- for video format support
• libmpv -- for GPU-accelerated video playback in the app

1. Install the prerequisites

Pick the one command for your platform:

Windows (using winget, built into Windows 10/11):

winget install Python.Python.3.12 Gyan.FFmpeg mpv

After this finishes, close and reopen your terminal so the new python and ffmpeg commands are found on your PATH.

macOS (using Homebrew):

brew install python ffmpeg mpv

Linux (Debian/Ubuntu):

sudo apt install python3 python3-pip ffmpeg libmpv-dev

2. Install RunRazor

pip install runrazor

That's it -- run runrazor to launch the app. Documentation is bundled with the package; run rrdocs to open it in your browser (rrdocs reframe opens a specific page).

RunRazor

The application window ties it all together: load a video (and a GPS track, if you have one), review and tune the cut points against the footage, reframe, and export.

runrazor

See rrdocs runrazor for all options, hotkeys, time format, and examples.

Reframe

Automatic subject tracking and reframing pipeline. Crops video from a stationary camera to follow a moving subject. You can use this directly without the RunRazor segmentation.

rrreframe input.mp4

You may get reasonable results without any additional arguments.

See rrdocs reframe for fine-tuning, deshake, horizon correction, 360 video input, interactive mode, profile mode, and cache options.

Split-screen comparison

Side-by-side comparison of two ski runs (or one run against its own mirror), phase-locked turn-by-turn. It runs on Reframe outputs: each clip's trajectory sidecar (written by default) drives automatic turn-apex detection, and one clip plays at native speed while the other is retimed per turn segment to stay in sync.

rrreframe runA.mp4 --output a.mp4
rrreframe runB.mp4 --output b.mp4
rrcompare a.mp4 b.mp4 -o compare.mp4

To compare against an external clip that was never reframed (or to fix wrong auto-detected turns), tag its apexes with rrtag clip.mp4. See rrdocs compare for turn pairing, mirroring, pane fit, retiming, manual tagging, and the editable alignment JSON.