Files
hyperframes/packages/engine
Vance Ingalls 43c88961b2 fix(engine): hand an empty audio track back instead of failing the render
ffmpeg exits 0 and writes a structurally valid but EMPTY wav whenever a clip's
trim starts past the end of its source — `-ss 10 -t 5` on a 2 s file. That
track reached `new OfflineAudioContext(channels, 0, rate)`, which throws
NotSupportedError, and the error travels past the mixer's per-track failure
collector: one mis-set `data-media-start` on one clip with one enabled effect
took the WHOLE render down with a RenderQualityError.

An empty track has nothing to process, so applyAudioFxChain now hands the input
back the way it already does for a chain with nothing enabled — before paying
for a browser to decide it. The runtime stub guards the same case at the point
the constructor would actually blow up, since it is reachable by any other
caller of the injected script.

The test falsifies against the real browser path: removing the guard
reproduces `NotSupportedError: The number of frames provided (0) is less than
the minimum bound (1)`.
2026-08-08 10:35:02 -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