Files
Vance Ingalls 147bb737c9 test(engine): add ffprobe-unavailable fallback regression tests (#379)
## Summary

Mock `node:child_process.spawn` to surface `ENOENT` and verify ffprobe's three callers behave correctly when ffprobe is missing.

## Why

`Chunk 9B` of `plans/hdr-followups.md`. The PNG cICP fallback in `extractMediaMetadata` was added to support environments without ffprobe, but no test pinned the behavior — silently regressing it would break HDR image support on any system without ffprobe installed.

## What changed

`packages/engine/src/utils/ffprobe.test.ts`: mocks `child_process.spawn` to surface `ENOENT` and asserts:

- `extractMediaMetadata` falls back to PNG cICP metadata for image inputs.
- `extractMediaMetadata` rethrows for non-image inputs lacking a still-image fallback.
- `extractAudioMetadata` + `analyzeKeyframeIntervals` propagate the install-hint error verbatim.

## Test plan

- [x] All new tests pass.
- [x] No production code changes — pure regression coverage of existing fallback behavior.

## Stack

Chunk 9B of `plans/hdr-followups.md`. Test-only change, independent of all other chunks.
2026-04-23 11:42:42 -07:00
..
2026-04-23 01:13:37 -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