Step 7 — Merge

Status: Planned (Chapter XVII)

Unlocks when: Episode is soundtrack_ready

Sets episode to: merged

MoviePy + FFmpeg assembles the final video: 1. Per scene: FFmpeg applies the effect to the background image for the narration duration → scene video clip 2. MoviePy concatenates all scene clips 3. Ambient music layered underneath — ducked -18dB under narration, full volume in gaps 4. Output: episode_{n}.mp4

Services: - studio/effects.py — per-scene animation via FFmpeg - studio/merge.py — merge_episode(episode_id) — clip assembly via MoviePy

File path: media/studio/{series_slug}/{book_slug}/chapters/{n}/episode_{n}.mp4