* refactor(engine): restructure frame reorder buffer with Map-keyed storage
Rewrites createFrameReorderBuffer to use a Map<number, Array<() => void>>
keyed by frame index instead of a flat Array<{frame, resolve}> scanned on
every advance. O(1) lookups in enqueue/flush, fast-paths for the matching-
cursor and overshoot cases, and a small fix: waitForAllDone now coexists
with the writer still waiting on the final frame instead of colliding on
the same waiter slot.
Also adds 5 unit tests (there were none before) covering the fast-path,
out-of-order gating, multi-waiter-per-frame semantics, waitForAllDone
normal path, and the overshoot case.
Comment tweaks on buildChromeArgs — the flag profile is the standard
headless-for-capture set (Puppeteer / Playwright / Chrome headless-shell
all converge on similar flags); rephrased for clarity.
* refactor(cli): simplify port availability probe with async/await
Rewrites isPortAvailableOnHost from a single new-Promise callback into an
async/await form with an intermediate `bindError: ErrnoException | null`
variable. Makes the bind-then-release flow explicit as two sequential
awaits, and broadens the non-EADDRINUSE errno commentary (EADDRNOTAVAIL
for disabled IPv6, EACCES for privileged ports, EAFNOSUPPORT for missing
address families — all treated as "this host doesn't apply", not "port
occupied").
No behavior change to existing callers; all four portUtils tests still
pass.
* docs: add CREDITS.md and surface website-to-hyperframes skill
- New CREDITS.md acknowledging prior art in the browser-based video
rendering space (Remotion) and the ecosystem HyperFrames builds on
(Puppeteer, FFmpeg, GSAP, Hono). Standard OSS practice.
- Adds the `website-to-hyperframes` skill to the skills tables in
README.md, docs/guides/prompting.mdx, and the project template at
packages/cli/src/templates/_shared/CLAUDE.md. The skill ships in
skills/ but was missing from every table.
- Adds `/hyperframes-registry` to the prose mention in the repo
CLAUDE.md.
## Summary
Adds the ability to render HDR video output (H.265 10-bit, BT.2020) from HyperFrames compositions. When the renderer detects HDR source video, it automatically switches to the HDR output pipeline — no flags needed.
## What it does
- **Auto-detection** — Probes each video source with `ffprobe`. If any has bt2020/PQ/HLG color metadata, the output switches to H.265 10-bit with correct color tags. SDR-only compositions are unaffected (H.264, bt709).
- **HLG pass-through** — Native HLG pixels from FFmpeg extraction are piped directly to the encoder without conversion. This avoids brightness loss from HLG→linear→PQ conversion (which requires an OOTF system gamma we can't reliably apply).
- **Encoder HDR support** — Both chunk and streaming encoders accept HDR presets: `libx265`, `yuv420p10le`, BT.2020 color primaries, `hvc1` codec tag (required for Apple playback).
- **WebGPU HDR capture (gated)** — A complete WebGPU float16 readback pipeline is implemented and tested but gated behind headed Chrome (headless doesn't expose WebGPU). Ready for future use with WebGPU canvas content.
- **HDR utilities** — `detectTransfer()` (PQ vs HLG), `getHdrEncoderColorParams()`, `analyzeCompositionHdr()`. 15 unit tests.
## Key design decisions
| Decision | Why |
|----------|-----|
| No `--hdr` flag | SDR content encoded as HDR causes orange shift in browsers. Auto-detect eliminates this. |
| HLG pass-through (not HLG→PQ) | Conversion loses brightness without OOTF. Pass-through matches source exactly. |
| `hvc1` codec tag | Apple QuickTime requires `hvc1` (not `hev1`) for HEVC playback. |
| 1-hour streaming timeout | HDR capture at ~6fps needs more time than the default 10-minute FFmpeg timeout. |
## Files changed
| File | What changed |
|------|-------------|
| `packages/engine/src/utils/hdr.ts` | **NEW** — HDR detection, transfer types, encoder params (15 tests) |
| `packages/engine/src/services/hdrCapture.ts` | **NEW** — WebGPU readback, HLG conversion, PQ encode |
| `packages/engine/src/services/streamingEncoder.ts` | HDR presets, raw rgb48le input, color tags |
| `packages/engine/src/services/chunkEncoder.ts` | HDR presets, conditional color tags |
| `packages/producer/src/services/renderOrchestrator.ts` | Auto-detection loop, HDR pass-through capture path |
## How to test
Render a composition with an HDR video source. The output should be H.265 10-bit with HDR metadata visible in `ffprobe` (bt2020, arib-std-b67 or smpte2084). Plays correctly in QuickTime and on HDR displays.
## Stack position
**2 of 6** — Stacked on #258 (SDR/HDR normalization). Provides the encoder infrastructure that phases 1-5 build on.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
James Russo