Fill Background Darken

Dims the background fill by a percentage so the sharp foreground video stands out. Applies when fit=fill (or fit=fillmax) is used with fill=blur or fill=image.

fill-darken accepts an integer from 0 (no dimming) to 100 (fully black). The default is 20 — a subtle 20% dimming that gives the blurred background a polished look out of the box.

Set fill-darken=0 to disable dimming entirely and show the blurred background at full brightness.