mirror of
https://github.com/heygen-com/hyperframes.git
synced 2026-11-03 20:37:30 +00:00
Miguel Ángel
09c0307c3f
## What a user can do now
Render a video at 720p or 480p: `hyperframes render --resolution 720p` (or `480p`, or the presets `landscape-720p`, `portrait-480p`, `square-720p` and so on) gives a 1280×720 or 854×480 file from a 1080p composition, and the same presets work through the studio-server render route. Before, any preset smaller than the composition was refused ("Downsampling via --resolution is not supported").
## How
- `parsers/src/types.ts`: six presets, `{landscape,portrait,square}-{720p,480p}`, and the `720p` / `480p` aliases (aspect-agnostic, like `1080p` and `4k`). 480p at 16:9 is 854×480: 480 × 16/9 is 853.33, and 4:2:0 encoders need even sides.
- `checkOutputResolutionCompatibility` now allows a preset smaller than the composition. A smaller preset may be off by under one pixel on its long side (the 854); a larger one must still match exactly and be a whole multiple, as before. The aspect remap that `--resolution 1080p` / `4k` apply on their own (`suggestMatchingPreset`, used by the CLI preflight and the compile stage) returns only a preset in the asked tier, never another: with the looser match for smaller presets, a 1922×1080 composition asked for `4k` would otherwise have been remapped to 480p. It is refused instead, as before.
- `resolveDeviceScaleFactor` returns the long side's ratio, so a smaller preset renders at a device scale factor under 1: Chrome lays the page out at composition size and rasterizes each frame straight at 1280×720 or 854×480, the way 4K already renders at 2. For 480p that is 854/1920: the width lands on 854 exactly and the height's 480.375 rounds to 480, so no pad column is added. Output sizes round as Chrome rounds the screenshot.
- The streaming encoder was given the composition's size instead of the output size on both streaming paths (`renderOrchestrator.ts`). 4K never noticed, as both sizes are even; at 480p the encoder skipped its even-size pad and libx264 refused an odd frame (`width not divisible by 2 (853x480)`). It now gets the output size, as the disk-frame encode already did.
- The paths that refused DPR > 1 (BeginFrame, drawElement, the Linux fast-capture gate) now refuse any DPR other than 1, since none of them honor a scale; scaled renders take the screenshot path, as 4K does.
- `render/outputScaleRoute.ts`: the layered compositor (HDR content, and shader transitions in webm and mov) sizes its layers and encoder from the composition and never scales, so a scaled output on that route now stops with a named error, checked where every route and replan is settled (`syncCapturePlan`, beside motion blur's route check). Before, a 1080p request from a 4K composition with shader transitions as mov would have encoded 3840×2160. HDR with `--resolution` was already refused in preflight; 4K on this route had the same gap on main and gets the same error.
## What I measured
- Real renders from source on a Linux box (`bun src/cli.ts render registry/examples/nyt-graph --resolution 720p|480p|1080p`), checked with ffprobe: 720p `h264, 1280x720, yuv420p, 15.0 s`; 480p `h264, 854x480, yuv420p, 15.0 s`; 1080p unchanged at 1920x1080. A frame of each, looked at: same chart and layout, crisp text, and the 480p right-edge column is the page's own color (250,248,242), not a pad.
- Before the encoder-size fix the 480p render failed with `[libx264] width not divisible by 2 (853x480)`; after it, it renders.
- `outputScaleRoute.test.ts`: the real route choice for a 4K composition with shader transitions as mov (`outputSupportsPageSideShaderCompositing`, `shouldUseLayeredComposite`, `createCapturePlan`, `resolveDeviceScaleFactor`) lands on `hdr_layered` at scale 0.5 and is refused. CLI preflight and the compile stage both refuse `4k` on a 1922×1080 composition.
- fails without the fix: without the same-tier rule, the preflight and compile tests for 1922×1080 at `4k` pass the render through at 854×480; without the route check, the mov test does not throw.
- At d33c4458: producer `outputScaleRoute` + `compileStage` 18/18 three runs in a row, `shared` (bun) 9/9, cli `render` 104/104 once and its new test three runs in a row; tsc clean in producer and cli. Earlier at e72f6507: parsers `outputResolutionCompatibility` 20/20, core `index` 26/26, producer `resolveDeviceScaleFactor` 14/14, cli `render` + `parseOutputResolution` 122/122, studio-server `render` 53/53. The new cases fail on main (the presets don't exist; smaller presets are refused). tsc clean in parsers, engine, producer and cli; oxlint and oxfmt clean.
## What I did NOT exercise
- Distributed (Lambda / Cloud Run) renders at 720p/480p: the chunk worker's sizes round the same way, but I did not run a distributed render.
- Studio's render queue keeps its own copy of the rule (`RenderQueue.tsx` `scaleApplies`) and offers no 720p/480p option; unchanged here.
@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,
createCaptureSession,
initializeSession,
captureFrame,
closeCaptureSession,
} from "@hyperframes/engine";
// 1. Launch browser
const browserLease = await acquireBrowser({ captureMode: "beginFrame" });
// 2. Open a capture session
const session = createCaptureSession({
browser: browserLease.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 browserLease.release();
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