mirror of
https://github.com/heygen-com/hyperframes.git
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James Russo
07de7e61ed
## Description PR 1 of 4 in the WebM (VP9) distributed-rendering series. A gating experiment that proves closed-GOP libvpx-vp9 chunks survive `ffmpeg -f concat -c copy` losslessly, so the rest of the stack can ship Path A (concat-copy) rather than the slower re-encode-in-assemble fallback. Two changes: 1. **Closed-GOP VP9 encoder args.** `buildEncoderArgs` now lays `-g <chunkSize>`, `-keyint_min <chunkSize>`, `-auto-alt-ref 0`, and `-cpu-used 2` on libvpx-vp9 when `lockGopForChunkConcat=true`. Mirrors the existing libx264/libx265 branches. The alt-ref disable is load-bearing — libvpx-vp9's default non-displayable alt-ref frames can reach across chunk seams and break concat-copy. `-cpu-used 2` pins the speed/quality tradeoff so chunks encoded on workers with different libvpx-vp9 defaults produce visually consistent output across seams. Default (`lockGopForChunkConcat` unset) preserves the existing in-process VP9 path unchanged. 2. **Concat-copy smoke test** at `packages/producer/tests/distributed/_smoke/webm-concat-copy.test.ts`. Generates 60 PNGs via lavfi `testsrc2`, encodes them as 4 VP9 chunks of 15 frames using `buildEncoderArgs` with `lockGopForChunkConcat=true`, concat-copies via `ffmpeg -f concat -c copy`, then runs three independent verifications: `ffprobe -show_streams`, `ffmpeg -f null -` decode test, and `ffprobe -count_frames`. Each verification surfaces its failure fingerprint in the error message. Smoke test passes 6/6 locally → Path A works; the rest of the stack takes it. Also exports `buildEncoderArgs` from `@hyperframes/engine` so adapters / tests can construct args without re-implementing the contract. ## Testing - [x] `bunx vitest run --root packages/engine src/services/chunkEncoder.test.ts` — 62/62 pass (new VP9 closed-GOP tests included) - [x] `bun test packages/producer/tests/distributed/_smoke/webm-concat-copy.test.ts` — passes - [x] `bunx oxlint` + `bunx oxfmt --check` on all changed files — clean - [x] `bunx tsc --noEmit -p packages/engine/tsconfig.json` — clean 🤖 Generated with [Claude Code](https://claude.com/claude-code)
@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
Related packages
@hyperframes/core— types, parsers, frame adapters@hyperframes/producer— high-level render pipeline built on this enginehyperframes— CLI