Files
hyperframes/packages/engine
Vance Ingalls 714f662edd fix(engine): take the browser lease inside the try that releases it
The lease was acquired above the try, with `mkdtempSync` between the two — so a
failure there (a full disk, a read-only tmpdir) returned without ever reaching
the `finally` that releases it. A leaked pooled browser is worse than the error
that caused it: a pool with no leases left hangs every later render instead of
failing one.

The temp dir is now taken first and the lease inside the try, with the release
made conditional. The abort check moves above the acquire too, so an
already-cancelled track no longer takes a browser out of the pool just to hand
it straight back.

No test: the fix is the ordering of two resource acquisitions, and the only way
to observe it is to make mkdtempSync throw, which needs an injection seam that
does not exist here and would be more risk than the three lines it guards.
2026-08-08 10:37:16 -07:00
..
2026-08-03 22:48:00 -07:00
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,
  createCaptureSession,
  initializeSession,
  captureFrame,
  closeCaptureSession,
} from "@hyperframes/engine";

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

// 2. Open a capture session
const session = createCaptureSession({
  browser: browserLease.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 browserLease.release();

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

Documentation

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