Files
hyperframes/packages/engine
Vance Ingalls 30348af3f4 feat(producer): add shaderTransitionWorkerPool (hf#732 PR 3/5) (#758)
## Summary

PR 3 of 5 in the hf#732 decomposition stack. Adds a `worker_threads`-based pool that runs the shader-transition blend (one of 15 transition shaders) on a fixed-size worker pool. **No production wiring yet** — the pool stands alone; PR 4 wires it.

The shader blend is a hot inner loop over every pixel of every transition frame at 16bpc. Moving it off the main event loop removes the JS-event-loop ceiling that capped throughput in earlier hf#732 iterations.

### New files

- `packages/producer/src/services/shaderTransitionWorker.ts` — worker entry. Imports from `@hyperframes/engine/shader-transitions` (zero-import TS source).
- `packages/producer/src/services/shaderTransitionWorkerPool.ts` — fixed-size pool. Uses `transferList` so the 16bpc HDR `from`/`to`/`out` buffers move by ownership.
- `packages/producer/src/services/shaderTransitionWorkerPool.test.ts` — 6 vitest tests pinning byte-equivalence across all 15 shaders, transferList correctness, pool lifecycle. All pass.

### Build wiring

- `packages/cli/tsup.config.ts`: third tsup entry emits `dist/shaderTransitionWorker.js`.
- `packages/producer/build.mjs`: fourth esbuild entry for direct producer consumers.
- `packages/engine/package.json`: adds `./shader-transitions` subpath export.

## Stack

Stacked on top of #757 (PR 2: pngDecodeBlit pool). No behavior change in any render.

## Test plan

- [x] 6 pool tests pass
- [x] Producer + engine typecheck clean
- [x] oxlint clean

— Vai
2026-05-13 15:17:58 -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,
  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