Files
hyperframes/packages/engine
Miguel Ángel 0f938841cd fix(core,engine): guard volume probe cache and restore PCM cursor (#1119)
Two perf fixes caught in #1118 review:

1. Cache guard: probeAndCacheVolumeKeyframes now short-circuits when
   the element is already in volumeKeyframeCache. Without the guard
   every bindMediaMetadataListeners call (every 30 RAF ticks) re-probed
   all bound elements — N elements × full-composition timeline seeks at
   60 Hz regardless of whether keyframes were already known.
   bindRootTimelineIfAvailable still clears the cache on a new timeline
   capture so keyframes stay fresh when the composition is rebound.

2. PCM cursor: audioVolumeEnvelope.ts had the incremental segment
   cursor (O(N+M) overall) before #1118 extracted the interpolation into
   interpolateVolumeGain. The shared function restarts from segment=0 on
   each call — fine for the preview path (one call per RAF tick) but
   O(N×M) for the PCM path (one call per sample: 48 kHz × duration).
   Napkin math: a 10-min render went from ~30M to ~460M ops. Restored
   the inline incremental scan in the engine bake loop; engine now only
   imports normaliseEnvelope from core.
2026-05-29 10:33:10 -04:00
..
2026-05-28 23:51:08 -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,
  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