mirror of
https://github.com/heygen-com/hyperframes.git
synced 2026-09-01 19:42:03 +00:00
Miguel Ángel
267ffd3fca
## Problem Template-wrapped sub-compositions could still lose correct parent timing during render in more than one place. In the validated repros, a host sub-composition starting after the intro (and in one follow-up repro, starting at `20s` after earlier compositions) contained scene-local media inside it. On the broken paths: - template-wrapped media could be missed during compile and scheduled at raw scene-local time - already-correct first-pass offsets could be clobbered during `recompileWithResolutions()` - even after those two fixes, the browser-metadata reconcile step in `executeRenderJob()` could still overwrite a compiled global `end` with a scene-local `data-end` from the inlined DOM, clipping the tail off late-start sub-composition media ## What this fixes ### Template-wrapped media discovery - `parseVideoElements`, `parseImageElements`, and `parseAudioElements` now unwrap a single top-level `<template>` wrapper before scraping media - the unwrap helper is DOM-based, not regex-based, so it avoids the CodeQL backtracking warning and only unwraps the exact single-wrapper shape we want - multiple sibling templates or other top-level content are left untouched instead of being rewritten heuristically ### Offset preservation after duration resolution - `recompileWithResolutions()` now preserves the first-pass sub-composition media arrays when the already-inlined HTML no longer contains `[data-composition-src]` hosts - that prevents correctly offset media metadata from being overwritten by scene-local media parsed from the merged DOM ### Browser metadata reconciliation in the compiled time origin - browser-discovered media can still report scene-local `data-start` / `data-end` from the merged DOM after inlining - the producer now reprojects browser `end` values into the compiled element's time origin before reconciling them back into `composition.videos` / `composition.audios` - this prevents late-start sub-composition media from getting truncated back to a scene-local end during the probe phase ### Regression coverage - adds focused engine tests for the template unwrap helper - adds producer regression coverage for both the initial compile path and the post-inline `recompileWithResolutions()` path - adds producer regression coverage for late-start host compositions (`t≈20`) with scene-local media inside them - adds producer unit coverage for the browser-end reprojection helper used by the reconcile path ## Root cause There were three distinct renderer failures behind the bug: ### 1. Template contents were invisible to the media scrapers `parseSubCompositions()` reads raw sub-composition HTML and applies the host offset to discovered media. But the engine media helpers were querying the parsed document directly, and linkedom follows browser semantics here: top-level `<template>` contents live in a `DocumentFragment`, so `querySelectorAll()` never saw those `<video>` / `<audio>` / `<img>` nodes. That meant template-wrapped sub-compositions could silently produce zero discovered media during the first pass. ### 2. The duration-resolution recompile could clobber already-correct offsets After the browser resolves composition durations, `recompileWithResolutions()` reparses the already-inlined HTML. By that point the original `[data-composition-src]` hosts are gone, so `parseSubCompositions()` legitimately returns no nested media. The old code still rebuilt the deduped media arrays from the merged DOM, which let scene-local media parsed from the inlined HTML overwrite the correctly offset first-pass metadata. ### 3. The browser probe reconcile path mixed two timing coordinate systems `discoverMediaFromBrowser()` reads `data-start` / `data-end` directly from the live DOM after sub-compositions are already inlined. For nested media, those attributes can still be scene-local even though the compiled metadata has already been offset into the parent host timeline. The old reconcile path compared those values directly and overwrote `existing.end` whenever the numbers differed. For a late-start sub-composition, that could replace a correct global end like `25.5` with a scene-local end like `5.5`, cutting the clip off during render. ## Verification ### Local checks - `bun test packages/engine/src/utils/htmlTemplate.test.ts` - `bun test packages/producer/src/services/htmlCompiler.test.ts` - `bunx vitest run packages/producer/src/services/renderOrchestrator.test.ts` - `bun run --filter @hyperframes/engine test` - `bun run --filter @hyperframes/engine typecheck` - `bun run --filter @hyperframes/producer typecheck` - `bunx oxlint packages/engine/src/utils/htmlTemplate.ts packages/engine/src/utils/htmlTemplate.test.ts packages/producer/src/services/renderOrchestrator.ts packages/producer/src/services/renderOrchestrator.test.ts packages/producer/src/services/htmlCompiler.test.ts` - `bunx oxfmt --check packages/engine/src/utils/htmlTemplate.ts packages/engine/src/utils/htmlTemplate.test.ts` - `bun run build:producer` ### Render / browser verification Verified against two local repros: 1. **Early offset repro** - host starts at `2s` - child media is scene-local `0-4s` - compiled render summary keeps the child video/audio at `start: 2` - browser verification via `agent-browser` confirmed the `2.2s` frame still shows the child clip active in the host timeline 2. **Late offset repro** - earlier compositions run first, then the target host starts at `20s` - child media starts scene-local at `1.5s` and should remain visible through `24.5s` - compiled render summary keeps the child video/audio at `start: 21.5`, `end: 25.5` - browser verification via `agent-browser` confirmed the `24.5s` frame still shows the late clip visible, which is the exact tail-clipping case the old reconcile path could break ## Notes - the `/tmp/hf-pr475-repro` and `/tmp/hf-pr476-late-offset-repro` projects plus their browser-proof artifacts are verification-only and are not part of this PR - this PR stays narrowly scoped to sub-composition media timing across compile, recompile, and browser probe reconciliation; it does not broaden into general sub-composition HTML normalization beyond the single-wrapper case
@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