/render-stopmotion-hand-swatch-cycle

name: render-stopmotion-hand-swatch-cycle
description: Assemble a stop-motion hand-swatch-cycle product-demo ad from a config — a sequence of still PLATES (one hand swiping a single-barrel product across a test surface, the barrel + swatch changing per plate while the hand, background, crop, and lighting stay locked) is PNG→mp4 loop-encoded at each plate's own stop-motion hold (fast motion frames 150–250ms, per-shade ~380ms, hero beats 1100–1800ms), concat-demuxed with HARD cuts into a silent master, closed on a Playwright HTML-rendered branded end card (serif tagline + sans subtitle + real logo SVG over a hero BG, never AI-rendered text), and muxed with a pre-sourced music track playing under the end card with a fade tail (no VO). This is the FREE deterministic assembly stage (loop-encode + concat-demux + end-card render + music mux); the master-anchor plate, shade plates, and end-card BG come from create-image-gpt-image-fal and the track from create-music-elevenlabs. Use for the stopmotion-hand-swatch-cycle format.
status: active

render-stopmotion-hand-swatch-cycle

Assemble a **stop-motion hand-swatch-cycle** ad from a config: a fast, tactile product demo where a single hand swipes ONE product barrel across a test surface, and the shade of the barrel AND the painted swatch stripe changes on every frame while the hand, background, crop, and lighting hold still — cycling the variant family so the viewer self-identifies their match, then a hero-pick payoff and a branded end card. The hand, background color, test surface, hero variant and music are the recipe's user choices; this capability only assembles the plates it is given. This capability is the **FREE, deterministic assembly** — the per-plate PNG→mp4 loop encode, the concat-demux, the end-card render, and the music mux.

`scripts/config.example.json` is the worked example — reference only, never the default (Kestrel Art Supply "Swipe Your Color": an oil-pastel stick, a medium-tan hand, mustard-yellow background, round paper card; ~16.6s 1080×1920 9:16, ~24 cycle plates + finale beats + a 3s end card); `scripts/PIPELINE.md` maps every config block to its source step and `scripts/README.md` documents the free assembly.

Run

This is the **FREE, deterministic** assembly stage — it spends nothing. The paid inputs are separate capabilities — the master-anchor plate + the per-shade / motion / finale plates + the end-card hero BG (`create-image-gpt-image-fal`, gpt-image-2 EDIT mode, each plate anchored to the SAME master-anchor — never chained), and the music track (`create-music-elevenlabs`, or a brand-supplied mp3). Given the ordered plate PNGs + per-plate holds + the end-card hero BG + the brand logo SVG + the music track, `render-stopmotion-hand-swatch-cycle` loop-encodes each plate at its hold, concat-demuxes with hard cuts into a silent master, appends the HTML-rendered end card, and muxes the music under it → the master. Re-cuts (re-timed holds, a re-ordered cycle, a swapped end card) reuse the existing plates / track and spend nothing.

Contract (the free assembly)

• **Still plates, not i2v — held for tuned durations.** Each plate is a static PNG loop-encoded

(`ffmpeg -loop 1 -t <pose_hold_ms>`) to 1080×1920 @ 30fps crf18. This is stop-motion — discrete held frames, no camera moves, no character animation. Do not animate the plates.

• **Fast stop-motion cadence, HARD cuts.** Motion / half-painted plates hold 150–250ms, per-shade

plates ~380ms (or ~1000ms for a slower cycle), hero / bookend beats 1100–1800ms; average ~380ms. Concat-**demux** the plate mp4s in order with hard cuts (`ffmpeg -f concat`) — NO dissolves. The frame-swap tactility is the whole point; a crossfade erases it.

• **Concat-demux, not filter_complex.** The plates are silent stills, so the `concat` demuxer over

the ordered plate list is correct and cheapest. (`filter_complex` is only needed when clips carry mismatched audio — these don't.)

• **The music carries it — no VO.** A pre-sourced or generated instrumental in the chosen feel

(the demo's was ~128 BPM bright pop), volume ≈0.4, fade in/out. Do not add a spoken voiceover or a second bed.

• **End card via Playwright HTML from the real logo SVG — never AI-render brand text.** A serif

tagline + sans subtitle + the real logo SVG composited over a hero product/swatch BG by an HTML template (Chromium headless), rendered to a silent ~3s clip. A diffusion model garbles a wordmark.

• **Music plays UNDER the end card with a fade tail — no silent tail.** Mux the track over the whole

video including the end card, fade over the last ~0.5s so the video ends WITH the music.

• **FFmpeg composite, deterministic, FREE.** Loop-encode each plate, concat-demux on hard cuts,

append the end card, mux the music with a fade tail → a 1080×1920 h264+aac master (~16.6s). No paid calls, no keys (beyond the Playwright/Chromium the end-card render needs).