There’s a scene in the trailer for the 30th Oldenburg International Film Festival that tells you everything you need to know about the event. Festival co-founder and director Torsten Neumann, half in shadow, delivers a brooding monologue inspired by Marlon Brando’s “The Horror” speech from  Apocalypse Now  — except here, the existential dread comes not from war but from programming an independent film festival with global ambitions in a midsize German city. The production, cheekily titled  Oldenburg Now , was shot in an office building across the street from festival headquarters, with staff hauling in houseplants to approximate a Vietnamese jungle. It’s indie filmmaking in its purest form — improvised, resourceful and entirely in sync with the ethos Oldenburg has cultivated over the course of three decades. It is, in every conceivable way, a microbudget guerrilla filmmaking operation. And it is absolutely perfect.…