Files
terencecho 0986bd9e48 fix(player): drive composition ticks from widget-frame rAF via postMessage (#739)
* fix(player): drive composition ticks from widget-frame rAF via postMessage

Chromium throttles requestAnimationFrame in deeply nested cross-origin
iframes. In Claude desktop (Electron), the composition iframe's own rAF
loop stalls, so GSAP is never seeked and animation freezes even when
TransportClock.isPlaying() is true.

The correct fix is to drive ticks from the widget-frame rAF, which lives
one level up and is not subject to the same throttling. When play() takes
the runtime bridge path (no direct timeline adapter), the player now starts
a parent-frame rAF loop that sends "tick" postMessages to the composition
iframe on every frame. The runtime's control bridge handles "tick" by calling
seekTimelineAndAdapters(clock.now()) if the clock is playing — identical to
what transportTick does on each rAF, just driven from outside.

The composition iframe's own rAF loop is unchanged and keeps running
normally in standard browsers. Seeking GSAP twice per frame is idempotent,
so there is no regression on claude.ai or any other non-throttled environment.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(player): address review issues in parent tick clock

- _paused must be false before _startParentTickClock runs; otherwise
  the first RAF callback sees _paused=true and self-terminates immediately

- Guard _startParentTickClock behind this._ready && !this._directTimelineAdapter
  so tick messages aren't sent into an uninitialized iframe when play() is
  called before the composition probe has resolved

- Add clock.reachedEnd() check to onTick so end-of-composition handling
  (pause, seek-to-end, postState) runs even when the composition iframe
  RAF is fully throttled

- Stop the parent tick clock in seek() alongside _stopDirectTimelineClock
  to avoid burning CPU frames while paused after a scrub

- Add onTick to bridge.test.ts createMockDeps() and add a dispatch test

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* chore: bump versions to 0.6.5-alpha.0 for testing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-13 14:01:53 -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