Scripting

PixelFlow scripts build a graph. They do not render frames directly.

Required output

Every valid script must assign exactly one top-level final clip to output.

These cases are errors:

• missing output,
• multiple top-level output assignments,
• non-clip value assigned to output.

Script responsibilities

Current script layer is responsible for:

• parameter injection,
• source and filter call coercion,
• namespace sugar rewrite,
• graph construction.

Real source probing and FFMS2 indexing happen later in source indexing, not while parsing script text.