Files
hyperframes/packages/engine
Vance Ingalls 3089c8ee3a build(lfs): track tests/*/src/*.png via Git LFS (#376)
## Summary

Track `tests/*/src/*.png` via Git LFS to mirror the existing policy for golden videos and `.mp4` fixtures.

## Why

`Chunk 11C` of `plans/hdr-followups.md`. Without this rule, regression suites that grow PNG fixtures over time would bloat the working-tree history and slow shallow clones.

## What changed

- `.gitattributes`: add `tests/*/src/*.png` to the LFS-tracked patterns.
- Migrates the six existing PNG fixtures (1.6 MB combined: `hdr-photo-pq.png` plus `heygen-promo-preview-assets/` screenshots) onto LFS in the same commit so the rule applies retroactively.

## Test plan

- [x] `git lfs ls-files` includes the HDR PNG fixtures after commit.
- [x] Working tree size for these files goes from 1.6 MB to 6 × ~130 B LFS pointers.

## Stack

Chunk 11C of `plans/hdr-followups.md`. Independent of all code changes.
2026-04-23 09:31:48 -07:00
..
2026-04-23 01:13:37 -04:00
2026-03-21 22:43:56 -07:00

@hyperframes/engine

Seekable web-page-to-video rendering engine built on Puppeteer and FFmpeg.

Framework-agnostic: works with GSAP, Lottie, Three.js, CSS animations, or any web content that implements the window.__hf seek protocol.

Install

npm install @hyperframes/engine

Requirements: Node.js >= 22, Chrome/Chromium (auto-downloaded by Puppeteer), FFmpeg

What it does

The engine opens your HTML composition in a headless Chrome instance, seeks frame-by-frame using Chrome's HeadlessExperimental.beginFrame API, captures screenshots, and encodes them into video with FFmpeg.

Key services

Service Description
browserManager Launches and pools headless Chrome instances (chrome-headless-shell)
frameCapture Manages capture sessions — seek, screenshot, buffer lifecycle
screenshotService BeginFrame-based capture with CDP (Chrome DevTools Protocol)
chunkEncoder FFmpeg encoding with chunked concat, GPU detection, faststart
streamingEncoder Pipe frames to FFmpeg in real time (no intermediate PNGs on disk)
audioMixer Parse <audio> elements and mix audio tracks via FFmpeg
videoFrameExtractor Extract frames from <video> elements for compositing
parallelCoordinator Split frame ranges across worker processes
fileServer Serve local HTML files to the browser via Hono

Usage

import {
  acquireBrowser,
  releaseBrowser,
  createCaptureSession,
  initializeSession,
  captureFrame,
  closeCaptureSession,
} from "@hyperframes/engine";

// 1. Launch browser
const browser = await acquireBrowser({ captureMode: "beginFrame" });

// 2. Open a capture session
const session = createCaptureSession({
  browser: browser.browser,
  url: "http://localhost:3000/my-composition.html",
  width: 1920,
  height: 1080,
  fps: 30,
});
await initializeSession(session);

// 3. Capture frames
for (let i = 0; i < totalFrames; i++) {
  await captureFrame(session, i, `/tmp/frames/frame-${i}.png`);
}

// 4. Clean up
await closeCaptureSession(session);
await releaseBrowser(browser);

Most users should use @hyperframes/producer or the hyperframes CLI instead of calling the engine directly.

Documentation

Full documentation: hyperframes.heygen.com/packages/engine