Files
hyperframes/packages/engine
Miguel Ángel a9482ed801 fix(engine): disable browser pool for parallel capture workers (#1087)
* fix(engine): disable browser pool for parallel capture in BeginFrame mode

BeginFrame's compositor is process-global — when multiple pages in the
same Chrome instance drive HeadlessExperimental.beginFrame concurrently,
they race the compositor and crash with "Protocol error: Target closed".

Only disable the pool when BeginFrame mode would actually be active
(Linux + headless-shell + not forceScreenshot). Screenshot mode
(macOS/Windows) is unaffected and keeps the pool for memory efficiency.

Also extracts the frame capture loop into captureFrameRange to reduce
function complexity in executeWorkerTask.

* fix(engine): include supersampling in BeginFrame-mode predicate

Match the full capture-mode predicate from createCaptureSession:
DPR > 1 (supersampling) forces screenshot mode, which is pool-safe.
Without this check, supersampled parallel renders on Linux would
unnecessarily launch separate browsers.
2026-05-26 20:24:21 -04:00
..
2026-05-25 23:49:33 +00:00
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