SENDIT

Auto speed-ramp your climbing sends. Drop in a video, and SENDIT slows down the moves and fast-forwards the rest -- so 50% through the video means 50% up the boulder.

Weekend vibe-code project. MediaPipe pose detection + FFmpeg rendering + a retro VCR interface I couldn't stop adding to. Built for my outdoor climbing videos but works on any climbing footage.

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The UI

The whole thing is styled like a piece of vintage rack-mount video gear -- CRT scanlines, VHS tracking noise, rotary knobs, fader sliders, tape counters, pilot lights. Every panel is a "module" in a dashboard grid with signal-flow lines connecting them.

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How it works

 ┌──────────┐     ┌──────────┐     ┌──────────┐     ┌──────────┐
 │  UPLOAD  │────▶│ ANALYZE  │────▶│  TWEAK   │────▶│  RENDER  │
 │          │     │          │     │          │     │          │
 │ drop a   │     │ MediaPipe│     │ timeline │     │ FFmpeg   │
 │ .mp4     │     │ pose     │     │ editor + │     │ + audio  │
 │          │     │ detection│     │ presets   │     │ stretch  │
 └──────────┘     └──────────┘     └──────────┘     └──────────┘

1. Upload a climbing video (.mp4, .mov, .avi, .mkv)
2. Analyze -- MediaPipe detects the climber's pose every frame, scores movement vs rest, tracks vertical progress up the wall
3. Tweak the speed curve in the interactive timeline editor, drag pins, or pick a preset
4. Render -- FFmpeg outputs the speed-ramped video with stabilization, audio time-stretch, and chapter overlays

Speed-ramp modes

Mode	What it does
Constant Progress	Output time = wall progress. At 50% of the video you're 50% up the boulder. Rest is auto-detected and fast-forwarded.
Action Highlight	Velocity-based scoring with per-limb weights. Big dynos get slow-mo, chalk-ups get skipped. Classic climbing edit.
Dynamic	Slows when center of mass moves fast -- catches dynos and big moves automatically.
Hybrid	Blends progress + action curves with a dedicated blend control.

Examples

Sample before/after renders live in examples/ -- see examples/README.md for the folder layout and how to add your own.

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Quickstart

# backend
pip install -e .

# frontend
cd app && npm install

Requires Python 3.9+, Node.js 18+, and FFmpeg on your PATH.

Optional person tracking (YOLO + ByteTrack) for multi-person scenes:

pip install -e ".[tracking]"

Usage

# terminal 1: API server
python server.py

# terminal 2: frontend
cd app && npm run dev

Open localhost:3000, drop in a video, hit ▶ ANALYZE, tweak the curve, and ● RENDER.

Keyboard shortcuts

Shortcut	Action
Ctrl/Cmd + Shift + A	Analyze / cancel
Ctrl/Cmd + Enter	Quick preview render
Ctrl/Cmd + Shift + Enter	Full render
Esc	Cancel active render
J / K / L	Seek back / play-pause / seek forward
, / .	Frame step

Full shortcut reference in docs/FEATURES.md.

Stack

Frontend	Next.js 16, React 19, Tailwind 4, Zustand
Backend	FastAPI, Python
Vision	MediaPipe, OpenCV, optional YOLO26 + ByteTrack
Render	FFmpeg, audio time-stretch, stabilization
Vibes	Press Start 2P + VT323 fonts, CRT scanlines, VHS tracking, neon everything

Architecture

server.py              FastAPI (upload → analyze → solve → render)
pipeline/
  pose.py              MediaPipe pose detection + sanitization
  movement.py          Movement & progress scoring
  speed_curve.py       Speed curve solvers (action/progress/hybrid)
  render.py            FFmpeg decode/encode + audio time-stretch
  stabilize.py         Pose-anchored + feature-based stabilization
  flow.py              Optical flow / camera motion estimation
  tracker.py           YOLO26 + ByteTrack person tracking (optional)
app/                   Next.js frontend
  components/          Timeline editor, settings, video player, VCR controls
  lib/                 API client, Zustand store, types

License

MIT