ui2v CLI

Standalone command-line renderer for ui2v JSON animations.

Requirements

• Node.js >= 18
• Chrome, Edge, or Puppeteer's bundled Chromium

The renderer does not require Electron, FFmpeg, or node-canvas. It launches a browser with Puppeteer, renders with the ui2v Canvas engine, encodes MP4 with WebCodecs, and writes the video back to the requested output path.

Build

bun install
bun run build

Commands

ui2v doctor
ui2v init my-video
ui2v validate animation.json
ui2v preview animation.json
ui2v render animation.json -o output.mp4

Render options:

ui2v render animation.json -o output.mp4 --quality high --fps 60
ui2v render animation.json -o output.mp4 --width 1280 --height 720 --render-scale 2
ui2v render animation.json -o output.mp4 --codec avc --bitrate 8000000
ui2v render animation.json -o output.mp4 --timeout 300

Currently, render supports MP4 output with AVC/H.264 by default. HEVC can be requested with --codec hevc when the local browser supports it. If --fps is omitted, the renderer uses the frame rate from the project JSON.

Use --render-scale to supersample frames before encoding. For example, --width 1280 --height 720 --render-scale 2 renders internally at 2560x1440, then downsamples to a 1280x720 video for cleaner edges and text.

Preview uses a 2x canvas pixel ratio by default for sharper browser playback. Use --pixel-ratio 1 for lower GPU usage, or increase it up to --pixel-ratio 4 when checking fine details:

ui2v preview animation.json --pixel-ratio 3

Local Development

node packages/cli/dist/cli.js doctor
node packages/cli/dist/cli.js preview examples/basic-text/animation.json
node packages/cli/dist/cli.js render examples/basic-text/animation.json -o .tmp/basic-text.mp4

If no browser is found, install Chrome or Edge, set PUPPETEER_EXECUTABLE_PATH, or run:

npx puppeteer browsers install chrome

License

MIT