Files
hyperframes/packages/engine
Vance IngallsandClaude Sonnet 5 8e506b7c50 feat(core): pitch shift — a granular shifter as the fifth FX worklet
Adds hf-pitchshift alongside the four existing dynamics worklets: a dual-tap
granular delay line, 100 ms grain, taps 180° apart so one is always
crossfading in as the other resets — hides the splice each tap makes on
wrap. Read-tap speed relative to the write head tracks the semitone ratio,
so pitch shifts without changing duration.

Registered through the same workletBuilder/dispose-message path the other
four use (so shapeOf never rebuilds on a param tweak, and a chain drop
retires it), wired into the registry with a plain-language copy entry and a
~0.2s chain tail (two grains). One implementation, shared by preview (Web
Audio in the page) and render (the same worklet run inside an
OfflineAudioContext in the headless browser) — confirmed by a browser-render
test that measures the actual output frequency, not just that it differs
from input.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-20 02:08:26 -07:00
..
2026-08-19 19:28:13 -04:00

@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