Miguel Ángel 95bf333895 fix: stabilize apple master timeline and playback (#419)
## Summary
- preserve authored non-root composition timing before runtime sanitization so Studio can build the correct master timeline for chained subcompositions
- prefer the fresh runtime source in Studio dev so local preview does not serve a stale `/api/runtime.js`
- restrict preserved authored timing inference to the Studio timeline payload instead of the general runtime resolver

## What this fixes
This PR fixes the Apple presentation class of failures where the root `index.html` / `Master` view looked correct at first and then collapsed into an incorrect short timeline.

Before this change:
- the master transport could report a short duration like `0:12` instead of the real deck length (`2:21` in the Apple project)
- composition clips bunched near the start instead of laying out sequentially across the deck
- seeking into later parts of the deck would land in the wrong place or show the wrong active composition
- local Studio debugging could be misleading because dev sometimes served a stale runtime bundle

After this change:
- the master transport reflects the authored composition-chain duration
- master clips resolve linearly across the whole deck
- late seeks land on the correct slide window
- Studio dev uses the current runtime implementation, so local preview matches the branch you are testing

## Root cause
There were two related issues:

1. Studio/master timeline inference lost authored composition timing
- missing timing attrs were treated like `0` instead of `null`
- non-root composition `data-duration` / `data-end` were stripped before Studio timing resolution could use them
- root duration inference trusted an incomplete live timeline window instead of the authored composition chain

2. Preserved authored timing leaked into the general runtime resolver
- preserving authored timing was correct for Studio timeline payload generation
- but using those preserved attrs for normal runtime playback/render resolution caused visual regressions in producer CI
- the follow-up fix keeps authored timing available only for Studio payload collection while normal runtime playback continues to resolve from the real live timeline/media state

## Why the later regression fix was needed
The initial runtime change fixed the Apple master timeline, but it also widened timing inference in the core runtime too far. That caused Dockerized producer regressions because rendered visibility started respecting preserved authored timing where it should have relied on the live resolved runtime state.

The latest commit fixes that by splitting the behavior:
- Studio timeline payload: authored timing allowed
- general runtime resolver: authored timing ignored by default

That preserves the Apple master timeline fix without changing producer render semantics.

## Verification
### Local checks
- `bunx oxlint packages/core/src/runtime/init.ts packages/core/src/runtime/startResolver.ts packages/core/src/runtime/timeline.ts packages/core/src/runtime/startResolver.test.ts packages/core/src/runtime/timeline.test.ts packages/studio/vite.config.ts packages/cli/src/server/studioServer.ts`
- `bunx oxfmt --check packages/core/src/runtime/init.ts packages/core/src/runtime/startResolver.ts packages/core/src/runtime/timeline.ts packages/core/src/runtime/startResolver.test.ts packages/core/src/runtime/timeline.test.ts packages/studio/vite.config.ts packages/cli/src/server/studioServer.ts`
- `bun run --filter @hyperframes/core typecheck`
- `bun run --filter @hyperframes/studio typecheck`
- `bun run --filter @hyperframes/cli typecheck`
- `cd packages/core && bun run test src/runtime/startResolver.test.ts src/runtime/timeline.test.ts`
- `bun test packages/cli/src/server/studioServer.test.ts --timeout 20000`

### Browser proof
Tested in Studio with `agent-browser` against the Apple presentation project.
- root/master transport now shows `0:00 / 2:21`
- master clip manifest resolves sequentially (`slide-1 -> slide-2 -> slide-3 ...`)
- seeking to `120s` lands on a late slide instead of a collapsed early timeline state
- after refreshing onto the fresh runtime source, the visible later-slide media advanced correctly in local Studio playback

### CI-equivalent regression proof on devbox
The previously failing producer regressions were rerun on devbox using the same Dockerized path GitHub Actions uses:
- `docker build -f Dockerfile.test -t hyperframes-producer:test .`
- `docker run ... hyperframes-producer:test style-1-prod style-5-prod style-9-prod style-12-prod --sequential`

Those previously failing suites all passed after the runtime split fix:
- `style-1-prod`
- `style-5-prod`
- `style-9-prod`
- `style-12-prod`

## Notes
- the Apple project volume tweak stayed local-only for testing and is not part of this PR
- this PR fixes the master/root timeline bug and the runtime regression it introduced; it does not add general subtimeline authoring support
2026-04-23 04:05:11 +02:00
2026-03-21 22:43:56 -07:00

HyperFrames

npm version npm downloads License Node.js

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 and GSAP animations. In Claude Code, the skills register as slash commands — invoke /hyperframes to author compositions, /hyperframes-cli for CLI commands, and /gsap for animation help.

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

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/introduction — Quickstart | 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 CLI commands: init, lint, preview, render, transcribe, tts, doctor
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
gsap GSAP animation API, timelines, easing, ScrollTrigger, plugins, React/Vue/Svelte, performance

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

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Write HTML. Render video. Built for agents.
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