Files
miga-heygen 3964e36987 fix(engine): keep a render's dependent extraction-cache entry alive during long captures
The shared, size-capped video-frame extraction cache evicts entries whose
LRU-clock sentinel hasn't been touched in over an hour. That clock was set
once, at cache-hit lookup time, and never again — so a render holding a
compiled-dir symlink (or a still-open partial writer dir) into an entry for
longer than an hour could lose it to a concurrent render's GC sweep on the
same shared machine, leaving its frame reads a dangling ENOENT with no
retry.

Every active video's captured frame now renews its cache entry's clock,
throttled to once per 5 minutes per directory. touchCacheDir renews both
signals gcExtractionCache actually reads: the directory's own mtime (which
gates a still-open partial writer dir) and the completion sentinel's mtime
(which gates a published entry).

Co-Authored-By: Miguel Angel <miguel.sierra@heygen.com>
2026-09-12 23:41:24 +00:00
..
2026-09-12 13:03:01 -04:00

@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