composite-split-screen

Purpose

Combine two video clips into one frame — either stacked vertically (top-bottom) or side-by-side horizontally (left-right). The output is a single re-encoded .mp4 sized to the requested aspect ratio (default 9:16, i.e. 1080×1920). Duration equals the shorter of the two input clips.

This is a generic compositor: it knows nothing about brand zones, dividers, or avatar placement. Those concerns live in higher-level molecules (e.g. create-split-screen-creator-ad). This atom's job is one thing — geometric composition.

Three fill modes are supported for each zone:

• crop — scale the clip to fill the zone, cropping overflow (cover-fill).
• blur — fit the clip inside the zone and fill the remaining space with a blurred, cover-scaled version of the same clip (the "blur pill" look common in 9:16 repurposing).
• pad — fit the clip inside the zone and pad the remaining space with solid black.

Inputs