Files
hyperframes/packages/engine
Vance Ingalls 5de5df7fbb refactor(types): tighten type safety, dedupe HfTransitionMeta, prune dead LUT export (#366)
## Summary

Four small, mechanical type-safety cleanups across `engine`, `producer`, and `shader-transitions`. Zero behavior change — pure pre-cleanup so the rest of the stack ships against a tighter baseline.

## Why

`Chunk 6` of `plans/hdr-followups.md`. Several non-null assertions and a duplicate interface had accumulated as rebase artifacts and leftover work-in-progress; lands first because it touches files later chunks edit and removes friction during review.

## What changed

- `renderOrchestrator.ts`: replace `layers[layerIdx]!` with a `for (const [layerIdx, layer] of layers.entries())` so both index and element come from the iterator.
- `engine/types.ts`: drop the duplicate `HfTransitionMeta` interface (rebase artifact); the original definition above it is the documented one. The orphaned doc comment now precedes `HfProtocol`.
- `shader-transitions/hyper-shader.ts`: keep the local `HfTransitionMeta` declaration (the package ships as a standalone CDN bundle and must not depend on `@hyperframes/engine`), but add a sync comment pointing at the source of truth in `engine/src/types.ts`.
- `alphaBlit.ts` + `engine/index.ts`: drop `export` from `getSrgbToHdrLut` and remove its re-export. It was only ever called by the internal `blitRgba8OverRgb48le`; the public surface was dead code.

## Test plan

- [x] `bun run --filter @hyperframes/engine typecheck`
- [x] `bun run --filter @hyperframes/producer typecheck`
- [x] `bun run --filter @hyperframes/shader-transitions typecheck`
- [x] `bun run --filter @hyperframes/engine test` — 308/308 pass (no test changes; assertions removed in code only).

## Stack

Chunk 6 of `plans/hdr-followups.md`. Mechanical cleanup landed early per the suggested merge order.
2026-04-22 16:56:17 -07:00
..
2026-04-22 17:28:11 -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