Files
hyperframes/packages/engine
Rajan Pantha dae5b7b90b fix(engine): treat a sentineled cache entry with no frames as a miss (#3434)
lookupCacheEntry reported a hit purely on the presence of the
.hf-complete sentinel. The sentinel records that extraction finished,
not that the frames survived, so any per-file cleanup that empties the
directory leaves an entry that rehydrates with zero frames.

rehydrateCacheEntry then returns totalFrames: 0, the clip reaches the
coverage gate with nothing, and the render aborts with a message about
capture coverage. Because the poison is on disk rather than in the
composition, every later render of the project fails the same way with
nothing the user can change to fix it.

An entry now counts as a hit only when it carries the sentinel AND
still holds at least one frame file, so an emptied entry re-extracts.
The check is format-agnostic: a hit must be usable whatever extension
the frames carry.

Addresses the cache half of #3372.
2026-08-26 05:36:32 +00:00
..
2026-08-26 03:23:41 +00:00

@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