Files
hyperframes/packages/engine
Vance Ingalls 57b6858323 perf(engine): bump worker count cap for high-core hosts (hf#732 PR 1/5) (#756)
## Summary

PR 1 of 5 in the hf#732 decomposition stack. Bumps `parallelCoordinator`'s worker-count caps so high-core hosts can actually surface their hardware to renders:

- `ABSOLUTE_MAX_WORKERS`: 10 → 24 (explicit `--workers 16` now surfaces 16 DOM sessions instead of being silently clamped).
- `DEFAULT_SAFE_MAX_WORKERS` constant → `defaultSafeMaxWorkers()` function returning `max(6, min(16, floor(cpus/8)))`. On <=32-core hosts: unchanged (still 6). On 64/96/128-core hosts: 8/12/16.

No behavior change for typical hosts. Required prerequisite for the hybrid shader-transition path landed in PR 4.

## Test plan

- [x] Existing 7 `parallelCoordinator` tests pass
- [x] Engine typecheck clean
- [x] oxlint clean

## Stack

This is the base of the hf#732 decomposition stack:

1. **PR 1 (this)** — perf(engine): worker-count cap bump
2. PR 2 — feat(producer): add pngDecodeBlitWorkerPool
3. PR 3 — feat(producer): add shaderTransitionWorkerPool
4. PR 4 — perf(producer): hybrid layered/parallel path (the 2.22× speedup)
5. PR 5 — perf(producer): pipeline capture and shader-blend per-frame

Replaces the closed hf#732. See that issue for the original investigation; the architectural mismatch with #733's `captureHdrStage` extraction made a clean rebase impossible.

— Vai
2026-05-13 14:04:54 -07:00
..
2026-05-13 13:40:37 -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