--- name: creating-video description: "Create video from prompts by overseeing multi-clip AI generation end to end: write a shot list, generate each scene with Gemini Omni Flash (via the Cloudflare AI Gateway), review the results, and assemble them into a finished cut. Use when the user asks to make/generate a video, a short film, an animatic, or a multi-scene clip from a script or idea; when they mention Omni, Veo, text-to-video, or image-to-video; or when acting as the editing/director agent over generated footage. Triggers on 'make a video', 'generate a clip', 'short film', 'video from this script', 'turn this into a video', 'omni', 'veo', 'text to video', 'storyboard to video'. For transcoding/trimming/merging/GIF/subtitles use processing-video; for reading or summarizing existing video content use parsing-video." metadata: version: 0.2.1 --- # Creating Video Claude cannot render video itself, but it can direct a generator. This skill drives a multi-clip pipeline — **script → per-scene generation → review → assembly** — with Claude as the editing agent overseeing continuity and cut. Requires `ffmpeg`/`ffprobe` and Cloudflare AI Gateway creds (`/mnt/project/proxy.env`). **Default model: Gemini Omni Flash** (`gemini-omni-flash-preview`, Interactions API) — Google's own guidance as of 2026-07. It beats Veo on character consistency, reference-image control, text rendering, and conversational editing, and generates faster (~30–90 s/clip vs 1–3 min). Fall back to **Veo 3.1** (`scripts/veo_generate.py`, kept intact) only for scene extension, first+last-frame interpolation, or legacy pipelines — Omni supports neither. ## The five stages 1. **Shot list** — break the story into beats, up to 10 s each, one prompt per shot. 2. **Generate** — `scripts/omni_generate.py`, run detached. 3. **Review** — `parsing-video` on each clip **and** on the assembled cut. 4. **Assemble** — `scripts/assemble.py`, run detached. 5. **Iterate** — re-review, then **edit** failing scenes conversationally (cheaper and more stable than regenerating from scratch). ## Stage 2 — Generation (Omni via Cloudflare AI Gateway) Auth is CF AI Gateway BYOK: `proxy.env` supplies `CF_ACCOUNT_ID`, `CF_GATEWAY_ID`, `CF_API_TOKEN`; the Google key lives *inside* the gateway. Both the interactions call and the `files/{id}:download` retrieval route through it (verified 2026-07-20). **Run detached.** The Interactions API is *synchronous* — the HTTP call holds open for the whole generation (~30–90 s/clip). `bash_tool` caps at ~50 s. Launch and adaptive-wait on the `DONE` sentinel: ```bash # prompts.json = {"1": "...", "2": {"text": "...", "images": ["ref0.png"]}, ...} set -a; . /mnt/project/proxy.env; set +a (setsid python3 scripts/omni_generate.py prompts.json --out omni/ \ --negative "on-screen watermark" &) # then, in a separate call: timeout 45 sh -c 'while [ ! -f omni/DONE ]; do sleep 3; done'; cat omni/generate.log ``` **Gotchas (all verified 2026-07-20 — the script already handles them):** - **No dry run exists.** Even `input:""` returns 200 and bills a full generation (~58k video output tokens). Every request costs money; never "validate" with a throwaway call. - No `negativePrompt` parameter (Veo had one; Omni 400s on unsupported params). `--negative` folds into the prompt as "Do not include: X." - Videos >4MB need `delivery:"uri"` → poll `files/{id}` to ACTIVE → download via the gateway. The script always uses uri delivery, inline base64 as fallback. - Output is up to 10 s 1280×720 mp4 with synchronized audio + SynthID watermark. No video extension, no first↔last-frame interpolation, no multi-video referencing — those are Veo territory. - The egress proxy 503s on cold start → retry with backoff. **Omni defaults to multi-shot.** Left alone it invents its own cuts inside a clip, which fights a shot-list pipeline. Every per-scene prompt should say "single continuous shot" / "no scene cuts" unless the beat wants internal cuts. ## Stage 3 — Review (use the parsing-video skill) Contact-sheet **each clip and the assembled cut**. Per-clip sheets miss cross-clip continuity; the full-cut sheet is where character drift, prop jumps, and logic breaks show up in one read (Oskar, 2026-07-18: review the whole assembly, not just scenes). Scan every sheet against the **continuity checklist**: - **Character** — same face/hair/wardrobe across every shot they appear in. - **Prop** — same identity, size, color, and attachment point shot to shot. - **Physical logic** — is the world coherent (a window must be open before a bird lands on the sill)? - **Action completeness** — is the key action actually *shown*, not cut around? ## Stage 4 — Assembly (`scripts/assemble.py`) Trims each clip to its beat, crossfades, drops audio by default, optionally burns an overlay word, and holds the final frame so the ending lands. ```bash (setsid python3 scripts/assemble.py omni/scene_1.mp4 ... omni/scene_6.mp4 \ --out film.mp4 --tail-hold 1.3 &) ``` Run detached too — six trims plus a 30 s stitch exceed the bash ceiling on the single-core container. Diagnosed: abrupt ending → `--tail-hold`; jarring cuts between independently generated ambiences → audio dropped by default (`--keep-audio` to `acrossfade` instead). ## Stage 5 — Iterate by editing, not regenerating `results.json` stores each scene's `interaction_id`. A failed detail (wrong color, unwanted object, lighting) is a one-line conversational edit that preserves everything else: ```bash python3 scripts/omni_generate.py --edit \ "Make the scarf red. Keep everything else the same." --out omni/scene_3_v2.mp4 ``` Simple edit prompts work best; append "Keep everything else the same." Reserve full regeneration for scenes whose composition or action is wrong. (Editing requires `store=true`, the script's default.) ## Prompt craft — continuity is the hard part The failure modes below came from real crits on 2026-07-18 (Veo era). Omni narrows several of them but the disciplines still pay on the first pass. - **Pin characters and props with reference images** — the first-class fix for the drift that text locks never fully solved under Veo. Generate one canonical still per character/prop, put it in the scene's `images` list, and bind it in the prompt: `the woman is holding ` (refs start at 0; `` pins a starting frame instead). - **Still lock a character sheet in text.** One verbatim appearance/wardrobe block, reused in every shot with that character — references constrain, text directs. - **Lock the setting.** One room/location description across co-located scenes. - **Name the actor in every shot** ("the same woman's hands") — never leave it to the model to infer who is on screen. - **Spell out scene logic** — physical coherence, the correct order of beats, and *show* the payoff action rather than cutting away from it. - **Timing is promptable.** `[0-3s] ... [3-6s] ...` timecode syntax or natural language ("after 3 seconds, ...") controls beats inside a clip. - **On-screen text now renders reliably** — spell out exactly what any visible text should say (signs, labels, title cards). Burning text in assembly (`assemble.py --overlay-last`) remains an option for cross-clip title cards. - **Audio is promptable.** Describe the track ("no dialogue", "calm background music") or Omni invents one per clip — which still won't match across clips; assembly drops audio by default for that reason. ## Scope - Transcode / trim / merge / GIF / subtitles → **processing-video**. - Reading, summarizing, or QA of existing video content → **parsing-video** (also the review step here). - Scene extension / first+last-frame control → the retained Veo path (`scripts/veo_generate.py --list` to enumerate models; strings drift).