f84cc492de perf(engine): faster shader transitions via page-side WebGL compositing (#832)
* fix(cli): prefer puppeteer cache + numeric version sort (staff review)

Two correctness fixes from PR #821 self-review:

1. Cache priority order. Previous order was hyperframes-managed cache →
   puppeteer cache. HF cache is pinned to CHROME_VERSION (131-era) which
   lags 17+ releases behind upstream; if a user separately installed a
   newer chrome-headless-shell via @puppeteer/browsers install, the CLI
   would silently hand engine the older HF-cache binary while engine's
   own resolveHeadlessShellPath would have picked the newer one. Flip
   the priority so puppeteer cache wins, matching engine semantics.

2. Numeric (not lexicographic) version sort. `readdirSync.sort().reverse()`
   over names like `linux-148.0.7778.97` and `linux-99.0.6533.123` would
   return `linux-99...` first because character '9' outranks '1'. Parse
   each name into integer segments and compare them numerically.

Tests: add both-caches-populated and linux-148-beats-linux-99 cases.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* perf(engine): page-side compositing for shader transitions (opt-in spike)

Add an opt-in `--page-side-compositing` flag (CLI) backed by a new engine
config field `enablePageSideCompositing` and env var `HF_PAGE_SIDE_COMPOSITING`.
When set, SDR shader-transition compositions skip the Node-side layered blend
(the hf#677 chain) and instead run the shader inside Chrome via a page-side
WebGL canvas; the engine then captures ONE opaque RGB frame per output frame
via the existing streaming capture path.

This is the strongest non-beginFrame perf lever for Mac users, who cannot
take the beginFrame `~5×` path (Chromium structural limit, crbug.com/40656275).
Stacks on top of the hf#677 1.95× baseline.

Default OFF — existing fixture pins (byte-exact MP4 output) are preserved.
Opt-in path is intentionally PSNR-pinned, not byte-equal (WebGL is f32; Node
is f64). HDR content forces the existing layered path regardless.

Implementation:
- engine: new `EngineConfig.enablePageSideCompositing` (default false).
- producer/fileServer: new `HF_PAGE_SIDE_COMPOSITING_STUB` early-page script
  injected into the served HTML head when the flag is on.
- producer/renderOrchestrator: when the flag + no HDR + no png-sequence,
  route SDR transitions through the streaming path instead of the layered
  HDR stage.
- shader-transitions: new `engineModePageComposite.ts` installs a fullscreen
  WebGL compositor overlay and wraps `window.__hf.seek` so each seek inside
  a transition window captures both scenes via the Chromium
  `drawElementImage` API to GL textures, runs the fragment shader, and
  displays the composited result on the overlay canvas. The engine takes
  one screenshot per frame and sees the composited overlay.
- cli: new `--page-side-compositing` flag sets `HF_PAGE_SIDE_COMPOSITING=true`
  before producer load.
- scripts/page-side-compositing-smoke: bundled-CLI smoke that renders a
  representative fixture with and without the flag, validates the canary
  strings are in the shipped bundles, and writes a wall-time pair.

Determinism trade documented in the engine config doc-comment. The smoke
script enforces the bundled-CLI validation discipline from prior perf work
(see internal feedback note `validate_bundled_cli_not_dev_path`).

Runtime requirement: Chromium's `CanvasDrawElement` feature (already
enabled by the engine's `--enable-features=CanvasDrawElement` launch flag).
When the runtime feature is unavailable, the page-side installer logs a
warning and falls back to opacity-flip mode — the engine still takes the
streaming path; the transition window degrades to a hard scene swap. Vance
will validate on Mac Chrome where the feature is supported.

Co-Authored-By: Vai <vai@heygen.com>

* fix(shader-transitions): use html2canvas for page-side compositor capture

The original drawElementImage approach fails in engine render mode because
the virtual-time shim prevents Chromium from generating paint records for
cloned elements. drawElementImage requires a cached paint record from the
browser's compositor — clones created at capture time never receive one
because (a) shimmed rAFs deadlock inside the seek wrapper, (b) original
rAFs don't produce real paints under virtual-time control, and
(c) layoutsubtree canvases don't apply CSS stylesheet rules to children.

Switch scene capture to html2canvas (foreignObjectRendering: false), the
same JS-based renderer already used by the preview-mode fallback path in
capture.ts. html2canvas reads computed styles and renders via its own
canvas drawing pipeline with no dependency on the browser paint cycle.

Also fixes:
- Engine seek must return the result so Puppeteer awaits async seek
  promises (frameCapture.ts).
- GSAP opacity cache: compositor must restore scene opacity before seek,
  not after — GSAP caches inline values and skips re-writes.
- Support check gates on WebGL availability, not drawElementImage.

Perf: 15-scene shader-perf fixture (28s, 14 transitions, 30fps)
  Baseline (Node-side layered): 137s
  Page-side (html2canvas+WebGL): 33s → 4.1× speedup

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* refactor(shader-transitions): simplify review fixes for page-side compositor

- Use uploadTexture (zeroes canvas backing store after upload) to prevent
  ~2.2GB transient memory pressure across 280 html2canvas calls per render
- Add ignoreElements + stabilizeTransformedBoxShadows to html2canvas call,
  matching the preview-path capture.ts behavior
- Parallelize from/to scene captures with Promise.all
- Wrap post-capture render in try/finally so opacity is always restored
- Fix WebGL context leak in isPageSideCompositingSupported probe
- Remove dead ResolvedTransition.index field
- Export stabilizeTransformedBoxShadows from capture.ts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(producer): unify page-side compositing gating and Docker forwarding

Addresses three issues from staff review:

1. ignoreElements filter stripped all in-scene canvases (Chart.js, D3,
   p5.js) — narrowed to data-no-capture only since the compositor canvas
   is a body sibling never in the scene subtree.

2. Docker mode silently dropped --page-side-compositing — thread
   pageSideCompositing through DockerRenderOptions/buildDockerRunArgs
   with regression tests.

3. Fragmented gating across 4 independent sites could disagree:
   - Stub injection gated only on cfg flag (leaked into HDR/alpha)
   - Probe-created fileServer never got the stub
   - needsAlpha (WebM/MOV) not excluded from the gate
   - WebGL-unavailable fallback claimed layered path would run but
     orchestrator had already disabled it

   Fix: compute stub injection at the same site as the layered-bypass
   decision (after hasHdrContent is known), using addPreHeadScript on
   the already-running fileServer. Single predicate now gates both
   decisions, including !needsAlpha.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* perf(engine): two-phase drawElementImage capture for page-side compositing

Replace html2canvas with native drawElementImage for scene capture in
the page-side compositor. drawElementImage reads from the browser's own
paint cache, giving pixel-identical output to the preview path.

The blocker was that cloned elements inside layoutsubtree canvases have
no cached paint record under virtual time — the compositor only paints
when explicitly triggered. Fix: split the seek+composite into two phases
with an engine-forced paint between them.

Phase 1 (seek wrapper, page-side):
  - GSAP seek positions the timeline
  - Clone FROM/TO scenes into visible layoutsubtree staging canvases
  - Set window.__hf_page_composite_pending flag

Engine paint force (frameCapture.ts):
  - Detect pending flag after seek returns
  - Fire micro Page.captureScreenshot (1x1 clip) via CDP to force the
    browser compositor to paint all visible elements including staging
    canvas children

Phase 2 (page.evaluate, page-side):
  - drawElementImage reads the now-valid paint records
  - Upload textures to WebGL, run shader, show GL overlay

Key insight: staging canvases must be visible (not opacity:0) for the
browser to paint their children. They sit at z-index:-9998, behind
the main DOM and covered by the GL overlay during transitions.

Perf: 15-scene fixture (28s, 14 transitions, 30fps):
  Baseline (Node-side layered): 137s
  html2canvas + WebGL:           33s (3.7×)
  drawElementImage + WebGL:      21s (6.6×)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* perf(engine): optimize two-phase compositor hot path

- uploadTextureSource instead of uploadTexture: eliminates ~2.3GB of
  canvas buffer alloc/dealloc churn (persistent staging canvases don't
  need the one-shot zeroing behavior)
- Fold hasPending check into seek page.evaluate: eliminates one CDP
  round-trip per frame (~700 unnecessary IPC calls on non-transition
  frames)
- Fix renderShader error handling: on failure, leave source scenes
  visible as fallback instead of hiding both scenes + GL overlay
  (which produced black frames)
- Move mutable state declarations above resolveComposite to prevent
  TDZ risk on refactor

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(engine): staff review — staging cleanup, pending flag, beginFrame guard

- Clear staging canvas children when leaving transition window (prevents
  visible clone bleed-through on transparent compositions)
- Clear __hf_page_composite_pending on all resolveComposite exit paths
- Guard micro-screenshot paint force against beginFrame mode (CDP
  Page.captureScreenshot conflicts with beginFrame compositor control)
- Update CLI flag description: document video/canvas limitation, remove
  stale PSNR claim

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(engine): default-on page-side compositing for SDR shader transitions

Page-side compositing is now enabled by default for SDR shader-transition
renders without video content. The 6.6× speedup applies automatically —
no flag needed.

Auto-disables when:
- HDR content detected
- Alpha output (WebM/MOV/PNG-sequence)
- Composition contains <video> elements (cloneNode loses playback state)
- beginFrame capture mode (Linux headless)

Use --no-page-side-compositing to force the Node-side layered path.

Changes:
- Engine config: enablePageSideCompositing defaults to true
- CLI: flag default flipped to true; --no-page-side-compositing disables
- Orchestrator: added composition.videos.length === 0 gate
- Docker: forwards --no-page-side-compositing when explicitly disabled
- Config tests updated for new default

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(engine): support video elements on page-side compositing fast path

Three-phase capture protocol lets shader transitions render video scenes
without falling back to the slow Node-side layered pipeline:

1. Seek → compositor records transition metadata, sets pending flag
2. onBeforeCapture → video frame injector updates <img> replacements
3. prepare → cloneNode picks up current video frames, img.decode() awaits
4. micro-screenshot → forces browser to paint cloned elements
5. resolve → drawElementImage reads paint records, shader composites

Key changes:
- Remove `composition.videos.length === 0` gate from orchestrator
- Split compositor resolve into prepare (clone) + resolve (shader)
- Move onBeforeCapture before compositor prepare in frameCapture.ts
- Await img.decode() on cloned data-URI images to prevent stale frames
- Stop manipulating scene opacity in compositor (GL canvas overlay suffices)
- Add gsap.set declaration for shader-transitions ambient types
- Add video_missing_timing_attrs lint rule for <video> without id/data-start/data-end

Performance: compositions with video now render at 7.5s (6 workers) instead
of 2m38s on the layered path.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(core): auto-inject data-start on video/audio so frame extraction works without explicit attrs

The timing compiler now injects data-start="0" on <video> and <audio>
elements that lack it. This makes discoverMediaFromBrowser() find the
element (it queries video[data-start]), so the frame extraction pipeline
activates automatically. Videos "just work" without requiring authors to
add data-start, data-end, or id attributes.

Also removes the video_missing_timing_attrs lint rule — the compiler
handles the missing attributes automatically, so the lint rule would
only false-positive.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(core): add data-hf-auto-start sentinel on auto-injected video timing

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(producer): add discoverVideoVisibilityFromTimeline for runtime video discovery

Seeks the GSAP timeline in Puppeteer to discover when each video's parent
scene is visible (opacity > 0). Uses coarse sampling at 100ms steps followed
by binary search refinement to frame-level precision (1/60s). Only processes
videos with the data-hf-auto-start sentinel so author-specified timing is
never overridden.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat(producer): integrate runtime video visibility discovery into probe stage

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(producer): trigger browser probe for auto-start videos, remove debug logging

The probe stage was skipping browser launch when composition duration was
already known, which meant discoverVideoVisibilityFromTimeline never ran.
Now needsBrowser also checks for data-hf-auto-start sentinel in compiled HTML.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(scripts): use mkdtempSync for smoke test work directory

Replaces hardcoded /tmp/hf-page-side-smoke with a unique temp directory
via mkdtempSync to resolve CodeQL "insecure temporary file" alert.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* style: format smoke test script

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-authored-by: Vai <vai@heygen.com>
2026-05-15 16:23:12 -07:00
2026-03-21 22:43:56 -07:00

HyperFrames

npm version npm downloads License Node.js Discord

Write HTML. Render video. Built for agents.

HyperFrames demo — HTML code on the left transforms into a rendered video on the right

Hyperframes is an open-source video rendering framework that lets you create, preview, and render HTML-based video compositions — with first-class support for AI agents.

Quick Start

Install the HyperFrames skills, then describe the video you want:

npx skills add heygen-com/hyperframes

This teaches your agent (Claude Code, Cursor, Gemini CLI, Codex) how to write correct compositions, GSAP timelines, Tailwind v4 browser-runtime styles, and first-party adapter animations. In Claude Code, the skills register as slash commands — invoke /hyperframes to author compositions, /hyperframes-cli for the dev-loop commands (init, lint, preview, render), /hyperframes-media for asset preprocessing (TTS, transcription, background removal), /tailwind for init --tailwind projects, /gsap for timeline animation help, or the adapter skills (/animejs, /css-animations, /lottie, /three, /waapi) when a composition uses those runtimes.

For Claude Design, open docs/guides/claude-design-hyperframes.md on GitHub and click the download button (↓) to save it, then attach the file to your Claude Design chat. It produces a valid first draft; refine in any AI coding agent. See the Claude Design guide.

For Codex specifically, the same skills are also exposed as an OpenAI Codex plugin — sparse-install just the plugin surface:

codex plugin marketplace add heygen-com/hyperframes --sparse .codex-plugin --sparse skills --sparse assets

For Claude Code, the repo also ships a Claude Code plugin manifest: test it locally with claude --plugin-dir .. The manifest intentionally omits skills because Claude Code auto-discovers the root skills/ directory by convention, and for marketplace submission use the title HyperFrames by HeyGen plus the black/white icon assets at assets/claude-code-icon-dark.svg and assets/claude-code-icon-light.svg for the two theme slots. For Cursor, the same skills are packaged as a Cursor plugin — install from the Cursor Marketplace, or sideload by cloning this repo and pointing Settings → Plugins → Load unpacked at the repo root.

Try it: example prompts

Copy any of these into your agent to get started. The /hyperframes prefix loads the skill context explicitly so you get correct output the first time.

Cold start — describe what you want:

Using /hyperframes, create a 10-second product intro with a fade-in title, a background video, and background music.

Warm start — turn existing context into a video:

Take a look at this GitHub repo https://github.com/heygen-com/hyperframes and explain its uses and architecture to me using /hyperframes.

Summarize the attached PDF into a 45-second pitch video using /hyperframes.

Turn this CSV into an animated bar chart race using /hyperframes.

Format-specific:

Make a 9:16 TikTok-style hook video about [topic] using /hyperframes, with bouncy captions synced to a TTS narration.

Iterate — talk to the agent like a video editor:

Make the title 2x bigger, swap to dark mode, and add a fade-out at the end.

Add a lower third at 0:03 with my name and title.

The agent handles scaffolding, animation, and rendering. See the prompting guide for more patterns.

Option 2: Start a project manually

npx hyperframes init my-video
cd my-video
npx hyperframes preview      # preview in browser (live reload)
npx hyperframes render       # render to MP4

hyperframes init installs skills automatically, so you can hand off to your AI agent at any point.

Requirements: Node.js >= 22, FFmpeg

Why Hyperframes?

  • HTML-native — compositions are HTML files with data attributes. No React, no proprietary DSL.
  • AI-first — agents already speak HTML. The CLI is non-interactive by default, designed for agent-driven workflows.
  • Deterministic rendering — same input = identical output. Built for automated pipelines.
  • Frame Adapter pattern — bring your own animation runtime (GSAP, Lottie, CSS, Three.js).

Hyperframes vs Remotion

Hyperframes is inspired by Remotion — we used Remotion at HeyGen in production, learned a ton from it, and kept attribution comments in the source for the patterns it pioneered (Chrome launch flags, image2pipe → FFmpeg streaming, frame buffering). Both tools drive headless Chrome and both are deterministic. They differ on one decision: what the primary author writes. Remotion's bet is React components; Hyperframes' bet is HTML.

Hyperframes Remotion
Authoring HTML + CSS + GSAP React components (TSX)
Build step None; index.html plays as-is Required (bundler)
Library-clock animations (GSAP, Anime.js, Motion One) Seekable, frame-accurate Plays at wall-clock during render
Arbitrary HTML / CSS passthrough Paste and animate Rewrite as JSX
Distributed rendering Single-machine today Lambda, production-ready

Licensing: fully open source vs source-available

Hyperframes is completely open source under Apache 2.0 — an OSI-approved license. Use it commercially at any scale, with no per-render fees, no seat caps, no company-size thresholds.

Remotion is source-available, not open source. The code is on GitHub under a custom Remotion License that requires a paid company license above small-team thresholds. It's a great product with a real team behind it — but if open-source licensing matters to you (OSI compliance, redistribution rights, no per-use fees), that's a first-order decision point.

Full write-up with benchmarks, an honest list of where each tool wins, and a GSAP side-by-side: Hyperframes vs Remotion guide.

How It Works

Define your video as HTML with data attributes:

<div id="stage" data-composition-id="my-video" data-start="0" data-width="1920" data-height="1080">
  <video
    id="clip-1"
    data-start="0"
    data-duration="5"
    data-track-index="0"
    src="intro.mp4"
    muted
    playsinline
  ></video>
  <img
    id="overlay"
    class="clip"
    data-start="2"
    data-duration="3"
    data-track-index="1"
    src="logo.png"
  />
  <audio
    id="bg-music"
    data-start="0"
    data-duration="9"
    data-track-index="2"
    data-volume="0.5"
    src="music.wav"
  ></audio>
</div>

Preview instantly in the browser. Render to MP4 locally or in Docker.

Catalog

50+ ready-to-use blocks and components — social overlays, shader transitions, data visualizations, and cinematic effects:

npx hyperframes add flash-through-white   # shader transition
npx hyperframes add instagram-follow      # social overlay
npx hyperframes add data-chart            # animated chart

Browse the full catalog at hyperframes.heygen.com/catalog.

Documentation

Full documentation at hyperframes.heygen.com/introductionQuickstart | Guides | API Reference | Catalog

Packages

Package Description
hyperframes CLI — create, preview, lint, and render compositions
@hyperframes/core Types, parsers, generators, linter, runtime, frame adapters
@hyperframes/engine Seekable page-to-video capture engine (Puppeteer + FFmpeg)
@hyperframes/producer Full rendering pipeline (capture + encode + audio mix)
@hyperframes/studio Browser-based composition editor UI
@hyperframes/player Embeddable <hyperframes-player> web component
@hyperframes/shader-transitions WebGL shader transitions for compositions

Skills

HyperFrames ships skills that teach AI agents framework-specific patterns that generic docs don't cover.

npx skills add heygen-com/hyperframes
Skill What it teaches
hyperframes HTML composition authoring, captions, TTS, audio-reactive animation, transitions
hyperframes-cli Dev-loop CLI: init, lint, inspect, preview, render, doctor
hyperframes-media Asset preprocessing: tts (Kokoro), transcribe (Whisper), remove-background (u2net) — voice/model/codec selection
hyperframes-registry Block and component installation via hyperframes add
website-to-hyperframes Capture a URL and turn it into a video — full website-to-video pipeline
remotion-to-hyperframes Translate a Remotion (React) composition into a HyperFrames HTML composition
gsap GSAP timelines for HyperFrames: paused registration, deterministic seeking, easing, sequencing, performance
animejs Anime.js animations and timelines registered on window.__hfAnime for deterministic HyperFrames seeking
css-animations CSS keyframe animation patterns that HyperFrames can discover, pause, and seek
lottie lottie-web and dotLottie players registered on window.__hfLottie with local assets and paused playback
three Three.js scenes that render from HyperFrames hf-seek events and window.__hfThreeTime instead of wall-clock time
waapi Web Animations API element.animate() patterns seeked through document.getAnimations()

Contributing

See CONTRIBUTING.md for guidelines.

Cloning the repo

The repo uses Git LFS for golden regression-test baselines under packages/producer/tests/**/output.mp4 (~240 MB of .mp4 files). If you're cloning the full repo for development, install Git LFS first:

# macOS
brew install git-lfs

# Ubuntu/Debian
sudo apt install git-lfs

# Windows
winget install GitHub.GitLFS
# (or install Git for Windows, which bundles Git LFS as an optional component)

# Then (once, per machine)
git lfs install

If you hit git-lfs filter-process: command not found during git clone or npx skills add heygen-com/hyperframes, install Git LFS and retry. You can also skip LFS content if you only need the source files:

GIT_LFS_SKIP_SMUDGE=1 git clone https://github.com/heygen-com/hyperframes.git

License

Apache 2.0

S
Description
Write HTML. Render video. Built for agents.
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