render-podcast-skit

Assemble a two-host podcast skit ad from a config: two hosts at a podcast desk do a snappy back-and-forth about the product, related however the user chose (friends, interviewer + guest, a doubter won over, two fans, a friendly debate). 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.

Choices

The creative calls are the user's, asked by the format recipe before any paid step — this assembly just renders whatever the config holds:

• tone — comedy banter, sincere, deadpan, hype, or calm/informative; shapes the script and voice style. Don't force humour: jokes only for the comedy tone. The demo used funny banter.
• set — home studio, living room, café, office, or an absurd product-irrelevant set (where the mismatch is the joke). The demo used a 24hr laundromat at 2am.
• dynamic — how the two hosts relate: two friends chatting, a host interviewing a guest, one doubting and the other winning them over, two fans swapping tips, or a friendly debate. Sets the script and each voice's role. Never default to skeptic vs believer. The demo used "a doubter won over".
• host_a / host_b — each host's gender, age, look. voices.HER / voices.HIM and who: HER|HIM are only the host A and host B SLOTS — they fix neither gender nor role. The demo used a young woman as host A (the doubter) and a young man as host B.

scripts/config.example.json is the worked example (Ladder run-02 "Laundromat 2am", ~49s 1080×1920 9:16, ~22 lines) — copy its structure, never its creative values; 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 chosen set's 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.