scenario-video-assembly
Scenario Video Assembly
Overview
Scenario has no editing tools on the MCP surface. Every compositor, concatenator, trimmer and captioner is a deterministic model run through model_run. The compositor, concatenator and trimmer ids are fixed and named below; Scenario ships two captioners, so that one is discovered with recommend. Connection and the core loop: see the scenario skill; the clips themselves: see scenario-video. If a sibling skill named here is missing from your available skills, ask the user to install it (npx skills add scenario-labs/skills --skill <name>); unattended, proceed from tool schemas and flag the gap.
Quick reference: pick the backend first
| Need | Model |
|---|---|
| Clips end to end, optional transitions | model_scenario-video-concat |
| Anything overlapping: overlay, bed, titles | model_scenario-compose-video |
| Still layout (thumbnails, sheets, key art) | model_scenario-compose-image |
These ids are constants: each is Scenario's single deterministic tool for its operation, so discovery would only re-derive it.
Concat is sequential: videos takes 2 to 50 files (never 1), preserveAudio (default true) carries each clip's own track into the cut, and the optional transitions array's "length must be number of videos - 1". Each entry is an object {type, duration}, never a bare string: type is one of 18 names read off the schema (fade, the default, is the plain crossfade; dissolve is a different effect; none a hard cut) and duration runs 0.1 to 5 seconds, default 0.5. Omit the array for hard cuts throughout, the right call whenever the brief does not ask one shot to flow into the next.
preserveAudio is not a guarantee of sync: a concatenated cut has come back with its audio drifting against the picture, with and without transitions (a confirmed defect at authoring time). A concat of clips carrying dialogue or effects is verified, never trusted: asset_get the output and compare properties.duration with the inputs' sum (each transition shortens the cut by up to its duration), then download it and check that the audio and video streams run the same length (a local probe of the download is inspection, not editing) and that a visible cue (a cut, a mouth opening, an impact) lands on its sound. When speech must stay locked to the picture, assemble in Video Studio instead: each clip layer carries its own track at its startTime, so a drift introduced by joining has nowhere to arise, at the price of hard cuts or per-layer fades in place of the transition set. Concat stays the tool for silent clips and for cuts whose bed is laid afterwards.