# KORGI W6 — movie delivery receipt

**Actor:** Helios (Cursor on Icarus). Not Loom.  
**Owner:** Mitchell Burns  
**Date:** 2026-09-13  
**Branch:** `cursor/w6-movie-export-0101`  
**Worktree:** `/Users/icarus/.cursor/worktrees/korgi-w6-movie-export-20260913`  
**Remote:** `gdrive` only (`/Users/icarus/Projects/korgi-gdrive.git`). No origin. No FF `main`. No KORGI Railway. Trunk zip/tgz not overwritten.

## Context snapshot

| Field | Value |
|---|---|
| `plan_branch` | `cursor/w6-movie-export-0101` |
| `tip` | `a510023eb5268f00280707ffead0e3aee53220e1` |
| `base` / `master_sha` | `4d355a5994467bbe64dc28b9b5817037e25a02ce` (W0 freeze; `4d355a5`) |
| `sync_method` | bootstrap (isolated worktree from freeze tip); this follow-up stays on the same branch |
| `colliding_prs` | W1 `cursor/w1-durable-host-0101`, W2 host/auth, W5 `cursor/w5-audio-import-0101` in flight. This chip did not edit `host/*`, `auth/*`, `wav.ts`, `actions/types.ts`, `evaluate-frame.ts`, or freeze docs. |
| `blocking_owner_items` | Full-song solo MV (Mitchell). W1 envelope land. |
| `non_claims` | See below. |

Cheap gates below were run on `a510023eb5268f00280707ffead0e3aee53220e1`. A later docs-only stamp on this branch does not change encoder/mux/job bytes.

Container/job work from `64b4b66` stands (WebM DocType, `V_VP9` + `A_OPUS`, cluster clamp, durable interrupt/resume, `parseWebmStrict` vs Packet F PCM). This follow-up replaces skip-all intra DC and the click/silence codebook as the **product** encode path.

## Encoder that actually shipped

In-process **`korgi_movie.wasm`** (W5 pattern: wasm in-tree, no user-facing FFmpeg).

| Piece | What |
|---|---|
| Wrapper | `crates/korgi-movie/korgi_movie.c` |
| Video | libvpx VP9 encoder **and** decoder. Profile 0, 4:2:0, `VP9E_SET_LOSSLESS`, keyframe-only (`VPX_EFLAG_FORCE_KF`) |
| Audio | libopus 48 kHz, 20 ms (`960` samples), `OPUS_APPLICATION_AUDIO`, 96 kbps |
| Ship | `src/lib/korgi/native/korgi_movie.wasm` (Node tests) and `public/korgi-movie/korgi_movie.wasm` (Studio fetch) |
| Glue | `src/lib/korgi/movie-wasm.ts` — `WebAssembly.Instance` + tiny `wasi_snapshot_preview1` stub (fd_*/path_open/proc_exit; **no filesystem**). Calls `_initialize`. |
| Rebuild | `scripts/build-korgi-movie-wasm.sh` (wasi-sdk clang + prebuilt `libvpx.a`/`libopus.a`). libvpx WASI `setjmp` is the in-tree stub `crates/korgi-movie/include-stubs/setjmp.h` (happy path never longjmps; errors trap). |
| Size | ~2.1 MiB wasm |

TypeScript skip-all intra DC remains **`encodeVp9KeyframeSkipAllProbe`**. Click/silence codebook remains **`encodeOpusClickSilenceProbe` / `OPUS_PROBE_*`**. Product `encodeVp9Keyframe` / `encodeOpusPcm16` / `exportMovieWithSound` / `encodeMovieFromProject` do **not** call those probes.

## Pixel-check method

Not a codec-spike DC field.

1. Packet B fixture: `drawingForEvaluatedFrame` + `renderFrame` at frame **0** (A1) and frame **2** (A2), 32×18 destination composite.
2. Product `encodeVp9Keyframe` (libvpx wasm) of each RGBA.
3. **Independent decode** of the bitstream via `korgi_vp9_decode_rgba` (libvpx decoder in the same wasm — round-trip through the compressed payload, not encoder internals).
4. Gates in `src/lib/korgi/export-pixels.test.ts`:
   - decoded unique RGB **> 1** (not a uniform DC block)
   - frame 0 payload ≠ skip-all probe; frame 0 ≠ frame 2
   - **luma MAE ≤ 2** vs renderer using the same JPEG-Y (`(77R+150G+29B+128)>>8`) as the C converter
   - A1 shirt sample luma > empty; A2 shirt sample luma > empty

**Near-exact (documented):** VP9 profile 0 is 4:2:0. Luma is lossless-matched (MAE ~0–0.2 on Packet B). Chroma is subsampled, so reconstructed **RGB is not bit-identical**. Alpha is flattened to 255 (VP9 profile 0 has no alpha). Host `ffmpeg` may decode `docs/oss/w6-export/w6-ffmpeg-8x8.webm` as extra evidence; it is **not** the product encoder and not required for the pixel gate.

## Sound-check method

`src/lib/korgi/opus-pcm.test.ts` + export-job / mux tests: 48 kHz PCM click bed → `encodeOpusPcm16` (libopus wasm) → `decodeOpusPacketsToPcm16` → `clickTimesInPcm16` on **decoded PCM**. Packets are not the TOC `0xbc` codebook. Opus pre-skip (~312 samples / 6.5 ms) is inside the 40 ms click-time window.

## Codec spike (this host)

| Probe | Result |
|---|---|
| Node | v22.23.1 |
| `VideoEncoder` / `AudioEncoder` | **absent** |
| Product video | in-process libvpx wasm `V_VP9` (lossless profile 0 keyframes of `renderFrame` RGBA) |
| Product audio | in-process libopus wasm `A_OPUS` of project PCM (WAV 48 kHz until W5 rebase) |
| FFmpeg on Icarus | present. **Not a product encoder.** Host-only fixture decode. LEDGER: skip FFmpeg. |
| `ffmpegNotProduct` | `true` |
| WebCodecs | optional browser fast path when `VideoEncoder` exists **and** there is no Opus track |
| MP4 adapter | `src/lib/korgi/mp4-adapter.ts` status `unverified` |

Bool coder goldens (skip-all probe only) unchanged: empty `0000`, skip+DC `6000`, alt64 `2aaaaaaaaaaaaaaa8000`.

## Container labeling

| Path | DocType | Video | Audio | Reader |
|---|---|---|---|---|
| Product movie | `webm` | `V_VP9` | `A_OPUS` + OpusHead | `parseWebmStrict` |
| Packet F probe | `matroska` | uncompressed dummy | `A_PCM/INT/LIT` | `parseMatroskaPcm`; **rejected** by `parseWebmStrict` |
| PCM as WebM | refused | — | `muxProductWebm` throws | do not label PCM as ordinary WebM |

Cluster law unchanged: SimpleBlock timecodes are signed int16 relative to Cluster Timestamp. New cluster before overflow (`MUX_TIMECODE_LIMIT_MS = 30000`, clamp at 32767). Do not “fix” by removing the clamp. 34s and 90s files use **≥2 clusters**.

## Job durability

`submitExportJob` writes status `request` (pin + `projectJson` + asset bytes + **libopus** packets) **before** picture encode. IndexedDB `korgi-export-jobs` in the browser; `memoryExportStore` in tests.

Pin: `documentFingerprint`, `journalSeq`, `takeRevision` (takes + celColumns), `audioRevision`, start/end.

Flow: request → running (per-frame checkpoint of libvpx keyframes) → artifact. `interruptAfter` stops mid-encode; a **fresh** store hydrated from JSON (no original-tab memory) `resumeExportJob`s to artifact.

Closing a tab does not discard a submitted request. Browser WebCodecs is an optional fast path, not the only route.

Not a second production document. Until W1 lands, mux/job call current `executeAction` / `drawingForEvaluatedFrame` / `projectFromPersisted`.

## Studio / GUI

Export movie is always enabled. `startDeskMovie` passes `assetBytes` + `journalSeq`. Frames go through `drawingForEvaluatedFrame` + `renderFrame` then libvpx wasm. Imported clips mix via `parseWav` (W5 import path; this chip does not edit `wav.ts`).

**GUI was not driven.** Headless `exportMovieWithSound` / `encodeMovieFromProject` and mux/job/pixel tests are the proof. Do not claim a live Studio click.

## Tests (this tip; do not sum historical packet greens)

```bash
npx tsc --noEmit
node --experimental-strip-types --test \
  src/lib/korgi/mux-webm-av.test.ts \
  src/lib/korgi/evaluate-frame.test.ts \
  src/lib/korgi/export-job.test.ts \
  src/lib/korgi/export-pixels.test.ts \
  src/lib/korgi/opus-pcm.test.ts \
  src/lib/korgi/vp9-bool.test.ts \
  src/lib/korgi/vp9-encode.test.ts \
  src/lib/stage-render.test.ts
```

| # | Case | Result |
|---|---|---|
| 1 | 10s WebM-strict VP9+Opus; picture from `renderFrame`; clicks from decoded Opus PCM | pass (`w6-10s-vp9-opus.webm`) |
| 2 | ≥34s cluster rollover | pass; `maxAbsMs > 32767`; ≥2 clusters; relative int16 in range |
| 3 | 90s synthetic soundtrack duration | pass; duration ≥ 89000; decoded-PCM clicks at 45s and 89s |
| 4 | Seek begin/mid/end | pass; all independent keyframes (headless `playbackAnchors`, not a GUI player) |
| 5 | Audio presence / duration / sync | pass; OpusHead; libopus packets of real PCM (not codebook TOC) |
| 6 | Worker interrupt/resume | pass; JSON dump into a fresh store; artifact WebM-strict; decoded Opus clicks |
| — | Pixel: frame 0 + later frame vs `renderFrame` luma; not DC | pass (`export-pixels.test.ts`) |
| — | Opus from 48 kHz click PCM, not click TOC | pass (`opus-pcm.test.ts`) |
| — | `importWav` 48 kHz → headless export | pass |
| — | Packet F PCM remains Matroska | pass; not the product movie |
| — | Product mux refuses PCM | pass |
| — | ffmpeg decode 8×8 product WebM when present | pass on this host |

## Files (this follow-up)

**New:** `crates/korgi-movie/korgi_movie.c`, `crates/korgi-movie/include-stubs/setjmp.h`, `scripts/build-korgi-movie-wasm.sh`, `src/lib/korgi/movie-wasm.ts`, `src/lib/korgi/native/korgi_movie.wasm`, `public/korgi-movie/korgi_movie.wasm`, `export-pixels.test.ts`, `opus-pcm.test.ts`.

**Edited:** `vp9-encode.ts`, `vp9-encode.test.ts`, `opus-encode.ts`, `export-job.ts`, `export-job.test.ts`, `mux-webm-av.test.ts`, this receipt, regenerable `docs/oss/w6-export/*.webm`.

**Did not edit:** `src/lib/korgi/host/*`, `actions/types.ts`, `mcp/server.ts`, `evaluate-frame.ts` (called only), `src/lib/auth/*`, `wav.ts`, freeze docs (`ASTRA_DESIGN.md`, contract, handback JSON).

## non_claims

- Full-song solo MV still needs Mitchell. **10s is not acceptance.** 90s is a synthetic click bed, not a song.
- VP9 RGB is **near-exact** (4:2:0 + opaque flatten), not bit-identical RGBA. Luma vs `renderFrame` is the pixel gate.
- PCM Packet F is **not** the product movie.
- MP4 / H.264 / AAC / ProRes / FFmpeg-in-product: not claimed. MP4 adapter stays `unverified`.
- GUI click in Studio was not driven this chip.
- W1 durable host envelope is not this tip. No second document. W5 audio import is not rebased here; WAV 48 kHz PCM is enough.
- No PixelLab spend. No Railway. No `main` fast-forward. No trunk zip overwrite. No origin.
- Do not add Packet A–F historical greens to this chip.

Helios, Icarus, 2026-09-13.