video-router git:20260825.cd5f782B

Immutable. This exact content is served forever at /api/v1/blob/1d9627fca440a7a0.

---
ownerAgent: 79df9cc89f5f
name: video-router
description_zh: 视频制作的产线路由与运行时锁定知识——按创意简报选「生成/合成/剪辑」能力轴并锁定主路径，开工前定调，避免中途无声切换。
description_en: Routing + runtime-lock knowledge for video production — pick the generate/compose/edit capability axis from the brief and lock the main path before work starts.
---

# video-router

Host-neutral knowledge for picking a video production line and locking it before work begins. This skill is read for guidance; it describes **what to decide**, not any host's tool mechanics.

## Unavailable production runtime

If the current system explicitly says that production tools, rendering, or
paid operations are unavailable, routing still must produce useful work. For a
clear or safely default-filled brief, select and state the line, then continue
in the same response with a complete **unexecuted production package**:
assumptions, script/narration, timed storyboard or shotlist, on-screen
copy/captions, visual and audio direction, provenance/fallback assets, export
target, preview-review checklist, and final QA checklist. Do not stop at a
plan-confirmation form and withhold the package. Clearly distinguish
planned files/media from produced files/media, and reserve future confirmation
only for an operation the unavailable runtime would actually execute.
Do not title the package “Production plan confirmation”. Make every timed scene
production-usable with narration, exact visible copy/caption, visual action,
and edit/transition instruction.
For a narrated package, include the full verbatim caption line for every
narration line; a short scene headline is additional on-screen copy, not a
substitute for captions. Final QA must explicitly probe the produced file and
verify it can be opened and played through after encoding, in addition to
checking dimensions, duration, nonblank frames, captions, safe zones, and audio.
The package language follows an explicit deliverable language in the request;
otherwise it follows the current User UI language, with English only as the
unsupported-or-unavailable fallback. Apply that language consistently to
narration, exact on-screen copy, and captions even when benchmark or transport
instructions are written in another language.

## The three capability axes

A finished video is built from one or more of three orthogonal axes. Decide which dominate, then lock them.

- **Generate (A)** — AI-generated footage/imagery: photoreal shots, b-roll, motion, talking-head. Use when the brief needs real-looking or cinematic visuals.
- **Compose (B)** — deterministic HTML composition: explainers, kinetic typography, motion graphics, captions / lower-thirds / overlays, data viz, title cards, transitions. Use when the visuals are designed rather than filmed. This is the default for explainer/animation work.
- **Edit (C)** — intelligent editing of supplied footage: evidence-based selection/cleanup, deterministic cut/join/reframe/captions/audio work, and semantic AI video editing when the user requests a pixel-level change that timeline operations cannot make.

## Decision rules

1. Decide whether supplied video is the **edit target** or only a **production input** before choosing a line:
   - When the user asks to change supplied video and the output keeps that footage or timeline as its spine, choose **Edit (C)**. Cuts, joins, reframing, captions, localization, deterministic overlays, and replacing or mixing audio—including supplied narration—remain edits of that video.
   - A video used only as a reference, motion/timing guide, or one input in a newly authored timeline does not select EDIT. Neither do supplied images, narration audio, music, or scripts. Route the new deliverable by the production work it needs.
   - Attachment type alone never decides the line. Ask whether to modify the existing video or make a new video from/reference it only when the requested output is genuinely ambiguous.
2. Read the brief (topic, aspect ratio, language, duration) and classify the **dominant work object**:
   - "explain / teach / animate / motion-graphics / kinetic text" → **Compose (B)** primary, optionally Generate (A) for b-roll.
   - "make footage of / cinematic / a scene of / a character doing" → **Generate (A)** primary, Compose (B) to overlay captions.
   - "cut / clip / trim / repurpose / make highlights / remove or change something in my video" → **Edit (C)** primary. Keep EDIT as the route even when one billable `operation:"edit"` video-model segment is required.
3. Most explainer/animation requests are **Compose-primary**: typographic and motion-graphic scenes assembled as an HTML composition, with AI imagery only where a shot genuinely needs it.
4. For supplied reference media, classify the requested relationship before choosing execution: `reproduce`, `edit`, or `guide`. Apply the same classification to images and videos regardless of which app, model, camera, or authoring format produced them. Images can control content/identity/composition/structure/style; videos can additionally control motion/timing/audio through temporal anchors.
5. Aspect ratio drives the canvas: 16:9 → 1920×1080, 9:16 → 1080×1920, 1:1 → 1080×1080.

## End-to-end (AUTO) — when the job spans lines

Pick a **single line** when one axis cleanly dominates (just trim a clip; just an explainer; just generate a scene). Adding captions, supplied narration, localization, reframing, or a deterministic overlay while keeping the supplied video's timeline as the spine remains EDIT. Route to **AUTO end-to-end** only when the primary timeline genuinely weaves MORE THAN ONE axis:

- "use my clip in the middle, author a full-frame motion-graphics opener, and add generated b-roll" (edit + compose + generate)
- "my footage in the middle, generate an opener, compose the stats" (edit + generate + compose)
- "make a finished video from these assets" where the assets alone are not the deliverable.

AUTO does not abandon the axes — it sequences them through one cross-modal plan (`stage-plan` builds the EDL, `stage-assemble` walks it), delegating each segment back to the generate / compose / edit lines. Choosing AUTO is itself the lock: the *primary* still gets named via the plan's `delivery_promise` (source_led / motion_led / compose_led / hybrid).

## Lock the runtime

- Decide the primary axis at the brief/proposal stage and **state it in the proposal**.
- Once locked, do not silently switch the primary axis mid-run. If a later step reveals the wrong choice, surface it to the user and re-confirm rather than quietly changing course.
- Layering is fine and expected (e.g. Compose captions over Generated footage); "locking" governs the **primary** path, not the allowed overlays.

## Runtime handoff

For a fully specified one-shot deterministic EDIT, hand off directly to
`stage-edit`: state the locked EDIT line, skip the direction artifact and plan,
probe the source, and execute the requested operation. Load `stage-decide` first
only when content or timing must be located from evidence.

For every other job with the production runtime available, routing ends at the
direction boundary, not at a production plan. For a Chinese UI, use the exact
gate-control title `制作方向确认` (never `创意方向确认`) and show only two or three
direction concepts plus the facts already locked by the brief. Do not write a
manifest, script, narration copy, or art direction before that choice. End the
direction question with `<plan-interaction status="open" />` — without it the
runtime reads the stop as an unfinished turn and bounces the reply.

## Boundary / non-goals

This skill only routes and locks. It does not author compositions or execute edits. Semantic editing is not a silent switch to GENERATE: it remains an EDIT/AUTO job whose EDL contains a signed, billable video `operation:"edit"` segment with the original reference video and preservation boundary.

The native VideoStudio lines are the only production path. Never substitute an
outside video framework for a missing native component. If a required component
is unavailable, say plainly which component is missing and stop rather than
inventing a replacement pipeline.