render-chatgpt-chat

# render-chatgpt-chat

The free renderer for the **chatgpt-chat** video ad format — the "I just asked
ChatGPT…" creative, where someone asks ChatGPT a question and the *streamed
assistant answer is the punchline* (the brand surfacing as the natural response).
Deterministic Playwright + ffmpeg assembly; no generative video of the UI, so the
bubble text and streamed answer stay pixel-crisp.

This is the **ChatGPT sibling of `render-imessage-chat`**. Reach for this one when
ChatGPT is the more credible host for the answer; reach for iMessage when the
punchline is a peer's reaction in a DM. The template recipe (DB) supplies the
per-brand `thread` + `timeline` + `end_card` config and gates the paid music call
(music bed → `create-music-elevenlabs`) to its own capability.

## What it renders

One continuous take — never scene-by-scene (every reload flickers):

1. **User types** in the composer with the iOS keyboard up (`composer-type`).
2. **Send-tap is ONE beat** — the user bubble pops, the keyboard slides down, and
   the header right-cluster swaps (`personPlus/dottedCircle` → `edit/more`) all on
   the same `t`. Never sequence them across frames.
3. **One gray loading dot** holds ~500ms (never three — three reads as iMessage
   typing, wrong app), silently (no SFX on the dot).
4. **The assistant answer streams in word-by-word** (`stream-words`, ~7 wps) with a
   soft opacity ramp; the conversation auto-scrolls to keep it in view.
5. **Crossfade to a designed end card** (wordmark + ⭐ proof row + trust trio + CTA
   pill) and **mux a ducked music bed** → master MP4.

The chat records at the ChatGPT-native **~9:19.5 (default 750×1624)** to match a real
iPhone screen recording. **Never stretch the chat to a different aspect ratio** — the
end card is scaled-to-fit + padded to the chat's dimensions in stitch, so the chat
is never touched.

## Run

```bash
cd scripts && npm install            # once — installs Playwright
npx playwright install chromium      # once
node record-chat.js     --config config.json --out-dir <work>   # → master-chat.mp4 + .sfx.json
node render-end-card.js --config config.json --out-dir <work>   # → scene-end-endcard.mp4
bash stitch.sh --chat <work>/master-chat.mp4 --end <work>/scene-end-endcard.mp4 \
     --sfx <work>/master-chat.sfx.json --out <work>/master-final.mp4 \
     --pad-color "#ffffff" [--music <work>/music-bed.mp3] [--also-1x1]
```

1. **`record-chat.js`** — reads `config.json` (`thread` + `timeline` + geometry),
   renders the bundled `create-chatgpt-mockup` HTML once with every message
   pending, walks the timeline on `requestAnimationFrame` inside the page, records
   it as one continuous MP4, and emits the deterministic SFX cue list.
2. **`render-end-card.js`** — fills `end-card.template.html` from `config.end_card`
   (wordmark/`logo_svg`, stars, proof, trust trio, CTA, colors) → still MP4. This is
   the SAME generic end card as `render-imessage-chat` (copied verbatim).
3. **`stitch.sh`** — normalizes the end card to the chat's dimensions, crossfades
   chat → end card, layers the subliminal ChatGPT SFX, optionally ducks a music bed
   under it, and optionally derives a 1:1 crop. All FREE ffmpeg. Pass
   `--pad-color` = `end_card.bg` (default `#ffffff`, ChatGPT light mode) so the pad
   under the end card is seamless.

## The chat body: bundled create-chatgpt-mockup

The ChatGPT chat HTML comes from **`create-chatgpt-mockup`** (its `generate.js` +
`templates/` produce the light-mode ChatGPT iOS HTML — status bar, header, message
rows, streaming word-spans, composer, and the inline iOS keyboard). Those files are
**bundled into `scripts/mockup/`** so this capability renders the chat body
**standalone** — no sibling fetch of `create-chatgpt-mockup` is required. `record-chat.js`
does `require('./mockup/generate.js')`.

The keyboard is inlined by the mockup (`renderKeyboard`) — no separate keyboard atom.

## Timeline events (consumed by record-chat.js)

| Kind | Meaning |
|---|---|
| `composer-type` | `{ text, dur_sec }` — type into the composer. SFX = one key-tap per word. |
| `composer-clear` | Wipe the composer instantly (fire at send-tap). |
| `keyboard-show` / `keyboard-hide` | Slide the iOS keyboard up / down. |
| `send-tap` | Pulse the send button. SFX = send-tap. |
| `pop` | `{ target: <msg-id> }` — reveal a message row. |
| `header-swap` | `{ value: "alt" }` — swap the header right-cluster. |
| `loading-dot-show` / `loading-dot-hide` | `{ target: <dot-id> }` — the single gray dot. |
| `send-state` | `{ value: "streaming"\|"active" }` — composer send-button state. |
| `stream-words` | `{ target, dur_sec, wps }` — reveal the assistant answer word-by-word. SFX = stream-tick every 12 words + response-done at the end. |
| `scroll-to` | `{ target, dur_ms }` — smooth-scroll a row into view. |

See `scripts/config.example.json` for the canonical thread + timeline (the "one
beat" send-tap and the streamed list answer are both wired there).

## Contract

- FREE assembly: Playwright record + ffmpeg composite/mux + the bundled SFX. No
  AI-rendered text — the bubbles, the streamed answer, and the end-card copy are all
  real HTML/PIL, never invented by a model.
- The recipe (DB) supplies the per-brand config: the `thread` (light-mode ChatGPT,
  assistant message set `stream: true`), the `timeline`, the `end_card` (prefer a
  real `logo_svg` wordmark), and an optional music bed.
- SFX are **subliminal by design** (ChatGPT has no native chime): key-tap -28dB,
  send-tap -20dB, stream-tick -32dB, response-done -22dB, and **never a cue on the
  loading dot**. Set `"sfx": false` in the config to ship the chat silent.

## Gaps / routing notes

- **Music bed** is an input, not generated here — the recipe gates it to
  `create-music-elevenlabs` (paid, proxy-routed, billed to the Ads agent) and passes
  the file into `stitch.sh --music`.
- **Bundled SFX are synthesized stand-ins.** The original four wavs
  (`key-tap`/`send-tap`/`stream-tick`/`response-done`) were lost