akshayDev17/ai-explainer-video

craft-video-assemble — the finished video

Part of the explainer-video-from-coursework pipeline — stage 8 of 8. The orchestrator over the render stage.

The pipeline's tools and scene hosts live in the sibling explainer-video-from-coursework skill: run them as node ../explainer-video-from-coursework/tools/<tool>.mjs, resolved against this skill's folder. Run from the project, so out/ scratch lands beside your notes.

Prerequisites: the script, out/<name>/<NN>/timeline.json, manifest.json, and narration.wav; on the machine, ffmpeg + headless Chromium (see SETUP.md).

A [setup] / Playwright cache not found failure means ffmpeg or Chromium is absent — relay the matching SETUP.md step to the user and re-run.

node ../explainer-video-from-coursework/tools/assemble.mjs --script out/<name>/scripts/<NN>-*.json \
                        --work out/<name>/<NN> --name <output> \
                        --dest <destination>

Per segment: render its own window through its own host + config, silent — parts are silent on purpose, because muxing narration onto each would restart the whole track at every boundary. Then concatenate (-c copy), mux the single measured narration track once, and verify. --only <key> renders a single segment, for a smoke test.

Asserts: every segment has a timeline window and a manifest.json entry · the windows tile the timeline with no gaps · the finished audio matches the narration at sample level.

Done when: the run exits 0 and prints [done] …<output>.mp4 with audio ok. The MP4 is copied to --dest.

Maintenance

If you modify this file, or the user asks to change this stage, tell the user that the main explainer-video-from-coursework skill's "Stage 8 — /assemble" section must be reconciled to match, and name that section in your reply.