# Guide: Video

> Writing video prompts and choosing a tier.

## Formulas `[vendor]`

- **Wan:** Entity + Scene + Motion; advanced: Entity(desc) + Scene(desc) +
  Motion(desc) + Aesthetic control + Stylization. Image-to-video: Motion +
  Camera only, the image fixes the rest. (Alibaba Model Studio guide.)
- **Veo 3.1:** [Cinematography] + [Subject] + [Action] + [Context] + [Style &
  Ambiance]; "prompt like you're directing a shot". Audio: `A woman says,
  "…"`, `SFX: thunder`, `Ambient noise: …`. Timestamps `[00:00-00:02]`.
- **Kling:** Subject + Subject Movement + Scene + (Camera + Lighting +
  Atmosphere). Movement "suitable for a 5-second video". Simple words. Weak at
  complex physical movement and counts. 2,500-char limit on prompt and negative.
- **FLUX 3 video (BFL skill):** opening frame → visible cause → physical
  response → payoff → continuity contract ("no cuts, transitions, frozen or
  repeated frames").

## Rules

1. **Action budget:** one subject action and one camera move per clip
   `[vendor: BFL]`. No cuts or scene changes inside a clip.
2. **Camera always explicit.** Wan defaults to a mild push-in when no camera
   is given `[community]`; write "static locked-off shot" if you want none.
3. **Order:** subject action (as it unfolds) → camera → environment motion →
   pace `[community]`. Spell out the physics; if there is no motion add
   ambient motion (wind, steam, drifting clouds) `[vendor: Wan extender]`.
4. **Style must be visible**: "tense" becomes rigid posture, hard side light
   and a slow push-in `[vendor: BFL]`. 2D styles get no film-camera terms
   `[vendor: Wan]`.
5. **Lint contradictions:** a locked-off camera cannot track; an extreme
   close-up cannot establish `[vendor: BFL]`.
6. **Length:** 60-200 words (Wan extender) `[vendor]`; simple sentences.
7. **Do not rely on** legible text, logos, many-item counts, lip-sync to
   specific words, or choreography; add typography and logos in post.
8. **Draft the first frame as an image**, approve it, then animate with
   image-to-video. Cheaper and more controllable `[inference]`; Veo's
   first-and-last-frame workflow does the same `[vendor: Google]`. Locally
   `video:fast` (p-video) animates an image: frame 0
   is the image, a transparent sprite comes back on an opaque background
   `[measured 2026-10-12]`. Hosted, `video:fast` is text-only: use `video:i2v`.
9. **After two structurally similar misses, change the concept or the
   production method, not the adjectives** `[vendor: BFL]`.

## Wan default negative prompt (pass verbatim on Wan models) `[vendor: Wan2.2 shared_config.py]`

```
色调艳丽，过曝，静态，细节模糊不清，字幕，风格，作品，画作，画面，静止，整体发灰，最差质量，低质量，JPEG压缩残留，丑陋的，残缺的，多余的手指，画得不好的手部，画得不好的脸部，畸形的，毁容的，形态畸形的肢体，手指融合，静止不动的画面，杂乱的背景，三条腿，背景人很多，倒着走
```

Meaning: garish colours, overexposed, static, blurry detail, subtitles, grey
cast, worst/low quality, JPEG artifacts, ugly, extra fingers, bad hands/faces,
deformed limbs, fused fingers, motionless frame, cluttered background, three
legs, crowded background, walking backwards.

## Vocabulary `[vendor: Wan]`

Shot sizes: extreme close-up, close-up, medium, full, extreme full. Angles:
eye-level, over-the-shoulder, high, low, top-down, aerial. Moves: push-in,
pull-out, tracking, orbit, fixed. Light: soft, hard, side, rim, backlight.
Time: dawn, dusk, golden hour, night. Tone: warm/cool, high/low saturation.

## DeepInfra video specifics

Video models return `video_url` as a `data:video/mp4;base64` URI (tens of MB)
or, for Veo, a `videos` list `[vendor: DeepInfra docs]`. Runs can take
minutes (one documented Wan2.2 run: 267 s). vincevangen submits with a webhook or
polls; MCP callers get a job id and use `vvgen_get_job`.