Files
hyperframes/packages/engine
xiayewang-heygenandClaude Opus 4.6 b021cb77be fix(engine): reconcile metadata duration after extraction delivers fewer frames (#4371)
When the probed video stream duration is inflated (container duration
fallback includes a longer audio track), FFmpeg delivers far fewer
frames than expected — typically exactly 50% for stock clips whose
audio is 2x the video length. The coverage gate then aborts the
render because it sees 50% coverage against the inflated expectation.

After extraction, if FFmpeg delivered <=60% of the predicted frames,
correct `metadata.videoStreamDurationSeconds` to the actual video
extent. This reconciliation feeds through to the coverage check via
the same `metadata` reference, so `expectedFramesForVideo` sees the
true duration without any interface changes.

This is a corrective complement to the preventive nb_frames
cross-check in extractMediaMetadata — it catches cases where
nb_frames is unavailable (MKV, live streams, fragmented MP4).

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-09-23 23:06:37 +00:00
..
2026-09-23 17:16:00 -04:00
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