Video Add Captions

Dependencies

/video-understand is a prerequisite. Run it first so captions use the validated word-level transcript and canonical timeline. Before starting, verify that it is installed. If it is not, warn the user that this prerequisite is missing and stop before processing media.

Require ffmpeg/ffprobe on PATH, Python with Pillow, and Node.js >= 22 (for the .mjs scripts and npx hyperframes, fetched on demand). hyperframes render/snapshot drives a headless Chrome — it manages its own chrome-headless-shell, and falls back to a system Chrome (set CHROME to override) when the cached one is unusable. Check these before processing media.

Scope

This skill owns caption grouping, style selection, review, and the transparent caption track. It does not transcribe, cut, retime, grade, reframe, or choose the delivery audio policy.