render-podcast-skit

Assemble a two-host fake-podcast skit ad from a config: a skeptic and a believer at an absurd themed podcast desk do a snappy back-and-forth about the product (the set is deliberately unrelated — that is the joke). Each line is its own lipsync clip so the edit can cut on the dialogue beat (~1.8s avg); this capability is the FREE, deterministic assembly that concatenates those clips, renders the WHITE captions, and appends the brand end card.

scripts/config.example.json is the worked example (Ladder run-02 "Laundromat 2am", ~49s 1080×1920 9:16, ~22 lines); 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: one ElevenLabs with-timestamps VO per line (one voice per host) via create-vo-elevenlabs; two photoreal base stills at the themed desk plus ~10 expression variants (mouths NEUTRAL/CLOSED, gpt-image-2 quality=high, not nano-banana) via create-image-gpt-image-fal; and one lipsync clip per (still, VO) pair via create-video-fal. Given the per-line clips + their VO timestamps + the brand wordmark SVG, render-podcast-skit walks the scenes in script order, builds the global caption timeline, renders the WHITE captions, hard-concats the clips, auto-appends the end card, and final-encodes crf28 → the master. Re-cuts reuse the existing VOs / stills / clips and cost $0.

Contract (the free assembly)

• Dialogue-carried, no music bed by default. The per-line VO is the audio; a podcast skit

needs no music (an optional low ambience is a taste call, off by default).

• One line = one scene = one hard cut, in script order. Hard-concat the per-line clips in

order (scale/pad to 1080×1920, re-encode) — no dissolves.

• Captions from the VO's OWN char-level timestamps, not Whisper (script-window). Build a

global words.json by offsetting each line's char-level word timings by the cumulative clip start, group into ≤5-word cues broken on sentence-final punctuation, and render WHITE #FFFFFF bottom-center captions (black outline), word-wrapped to stay in-frame and held ≥0.9s — PIL PNG overlays when the host ffmpeg lacks libass (common), else ASS. (Yellow 3-word karaoke was the old style, rejected in testing.) Whisper on the rendered clips mistimes; the VO timestamps are ground truth.

• End card via Playwright/PIL from the real wordmark — never AI-render brand text. The

lockup is a deterministic HTML → PNG → 2.5s mp4 from the brand's real wordmark SVG (black bg, brand wordmark, CTA pill, URL), auto-appended after the last line. A diffusion model garbles a wordmark.

• FFmpeg composite, deterministic, FREE. Concat the clips, overlay the WHITE caption PNGs (or

burn ASS via libass), append the end-card mp4, and final-encode -preset slow -crf 28 + aac 96k → a 1080×1920 h264+aac master (~6MB for ~28s; the old -crf 20 produced ~16MB). No paid calls, no keys.