osu file format v14

[Events]
//Storyboard Layer 0 (Background)
Sprite,Background,TopCentre,"img.jpg",320,240
 L,1000,1
  F,0,0,,1       // fade inside a loop with non-zero alpha and an earlier start time should be the true start time..
 F,0,2000,,0     // ..not a zero alpha fade with a later start time

Sprite,Background,TopCentre,"img.jpg",320,240
 L,2000,1
  F,0,0,24,0     // fade inside a loop with zero alpha but later start time than the top-level zero alpha start time.
  F,0,24,48,1
 F,0,1000,,1     // ..so this should be the true start time