Files
Miguel Ángel 1230657ed0 fix(studio,runtime,engine,compiler): 8 bug fixes — audio, render, timeline, Lottie, thumbnails, video render (#133)
## Summary

**Original 5 bugs fixed:**

- **Bug 1 — Audio silent after seek**: Added `Accept-Ranges` / `Content-Length` + `206 Partial Content` to the static asset server for byte-range seeking.
- **Bug 2 — Download 404 after restart**: Render list endpoint now registers on-disk renders into the in-memory job map.
- **Bug 3 — Timeline stops at GSAP end**: `resolveRootTimelineFromDocument` pads the GSAP timeline to match `data-duration` when the composition declares longer.
- **Bug 4 — Render stuck at 0%**: Store `jobState` reference (not spread copy) so async progress mutations reach the SSE stream.
- **Bug 5 — Lottie missing in preview/render**: Two fixes — (a) moved Lottie adapter before GSAP so `onUpdate` wins; (b) fixed bundler silently dropping external CDN `\<script src>` tags from sub-compositions (root cause: `$content(s).html()` returns `""` for external scripts).

**3 additional bugs fixed:**

- **Bug 6 — Blank thumbnails outside monorepo**: Implemented `generateThumbnail` in the CLI adapter using Puppeteer.
- **Bug 7 — Video empty in rendered sub-compositions**: Fixed `parseVideoElements` selector from `video[id][src]` to `video[src][data-start]` + auto-assign IDs.
- **Render errors**: Failed renders now show their error message in the renders panel.

## Commits

| Commit | Description |
| --- | --- |
| `3951c6f` | fix(studio): store render job reference instead of snapshot copy |
| `f331c30` | fix(studio): make previously-completed renders downloadable after restart |
| `a5e2d04` | fix(studio): add range request support for audio/video seeking in preview |
| `f24317a` | fix(runtime): pad GSAP timeline to data-duration when composition declares longer duration |
| `7cf38ca` | fix(runtime): fix Lottie adapter conflicting with GSAP-driven animations |
| `bc99209` | fix(studio): surface render error messages in the renders panel |
| `8fc9e8b` | fix(cli): implement generateThumbnail in studio adapter |
| `90277ea` | fix(engine): render videos inside sub-compositions that lack an explicit id |
| `f5bb579` | fix(compiler): preserve external CDN scripts from sub-compositions in bundle |

## Test plan

- [x] `golden-lyric-video`: seek → audio plays from seeked position
- [x] Any project: render → progress advances past 0%, reaches 100%
- [x] Any project: complete render, restart `hyperframes dev`, Download → works
- [x] `intro-vid`: play → runs full 5s (not stopping at 3s)
- [x] `hyperframe-build-up-demo`: play → rocket Lottie visible during 0-2s  verified
- [x] Outside monorepo: Compositions sidebar shows thumbnail images (not blank)
- [x] `bug.zip` project: render → video in polaroid sub-composition appears in output
- [x] Trigger a failed render → error message shown
2026-03-30 23:58:08 +02:00
..
2026-03-29 10:10:03 +00:00
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