random-time.swift

self.randomNum = arc4random_uniform(15) // range
self.someInt = Int(self.randomNum!)
self.someDouble = Double(self.someInt!) / 10
self.someCMTime = CMTime(seconds: someDouble!, preferredTimescale: 90000)

debugPrint(self.player.currentItem!.asset.duration)

if ((self.someCMTime?.seconds)! > self.player.currentItem!.asset.duration.seconds) {
    debugPrint("too much!")
} else {
    debugPrint(self.someCMTime!.seconds)
}

self.player.seek(to: self.someCMTime!)

print("duration in seconds = \(self.player.currentItem!.asset.duration.seconds)")
// print("timescale = \(self.player.currentItem!.asset.duration.timescale)")

self.someCMTime = self.player.currentItem!.asset.duration

self.someCMTime = CMTimeMakeWithSeconds(self.getRandomDouble(limit: self.player.currentItem!.asset.duration.seconds), preferredTimescale: self.player.currentItem!.asset.duration.timescale)
// self.someCMTime = CMTime(seconds: self.getRandomDouble(limit: self.player.currentItem!.asset.duration.seconds), preferredTimescale: self.player.currentItem!.asset.duration.timescale)

print("random time = \(Double((self.someCMTime?.seconds)!))")