;; Vignette effect - darken edges
;; Usage: python3 plan.py effects/vignette.sexp -p strength=0.6 | python3 execute.py - -d . -o output.mp4
;;
;; Parameters:
;;   strength: edge darkening amount (0.1 to 1.0, default: 0.6)

(recipe "vignette"
  :version "1.0"
  :encoding (:codec "libx264" :crf 20 :preset "medium" :audio-codec "aac" :fps 30)

  (effect vignette :path "sexp_effects/effects/vignette.sexp")

  ;; Default parameter (overridden by -p strength=N)
  (def strength 0.6)

  (def video (source :path "monday.webm"))
  (def clip (-> video (segment :start 0 :duration 10)))
  (def result (-> clip (effect vignette :strength strength)))
  result)