Files
hyperframes/packages/engine
Vance IngallsandClaude Fable 5.1 69024e17d1 fix(engine): keep ffmpeg's exit reason when it dies under a parked write
The field "write EPIPE" / "write EOF" render errors are this path:
writeFrame waits on once(stdin, "drain") for back-pressure to clear, ffmpeg
dies first, and Node rejects the drain wait with the stream's own error.
That rejection escaped writeFrame as the render error, so ffmpeg's exit code
and stderr — captured, but read only from the `false`-return path — were
discarded. With N workers feeding one encoder the writer is parked most of
the time, which is why the parallel cohort reads EPIPE where a single-worker
render reads "Streaming encoder exited before frame N: FFmpeg exited with
code …".

Wait for the exit to settle, then report it as the close race does. Both
halves are mutation-checked: rethrowing again fails the test, and returning
"exit" without awaiting settlement fails the synchronous getExitStatus read.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-18 20:53:09 -07:00
..
2026-09-18 19:41:06 -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