akshayDev17/ai-explainer-video

craft-video-render — frames to MP4

Part of the explainer-video-from-coursework pipeline — stage 7 of 8. The render primitive; the assemble stage drives it per segment. It can also run alone for QA stills during scene authoring.

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: a scene config and, for windowed renders, out/<name>/<NN>/timeline.json; on the machine, ffmpeg + headless Chromium (see SETUP.md).

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

node ../explainer-video-from-coursework/tools/render.mjs --scene "src/scene-diagram.html?scene=<name>" \
                      --range <t0>,<t1> --outdir out/<name>/<NN>/parts --name part-<key>

Renders one scene config over one window — headless Chromium via CDP → PNG sequence → ffmpeg H.264. It is not a whole-video renderer: --scene takes a single host?scene=<config>, so a multi-scene video is rendered window by window. A window rendered with no --narration comes out silent, which is what assembly wants.

--shots 6,20,34 renders QA stills instead of a full sequence; --keep-frames retains the PNG sequence.

Done when: the run exits 0 and prints [done] …<name>.mp4.

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 7 — /render" section must be reconciled to match, and name that section in your reply.