Swift: Trying to control time in AVAudioPlayerNode using UISlider - ios

Question

I'm using an AVAudioPlayerNode attached to an AVAudioEngine to play a sound.
to get the current time of the player I'm doing this:
extension AVAudioPlayerNode {
var currentTime: TimeInterval {
get {
if let nodeTime: AVAudioTime = self.lastRenderTime, let playerTime: AVAudioTime = self.playerTime(forNodeTime: nodeTime) {
return Double(playerTime.sampleTime) / playerTime.sampleRate
}
return 0
}
}
}
I have a slider that indicates the current time of the audio. When the user changes the slider value, on .ended event I have to change the current time of the player to that indicated in the slider.
To do so:
extension AVAudioPlayerNode {
func seekTo(value: Float, audioFile: AVAudioFile, duration: Float) {
if let nodetime = self.lastRenderTime{
let playerTime: AVAudioTime = self.playerTime(forNodeTime: nodetime)!
let sampleRate = self.outputFormat(forBus: 0).sampleRate
let newsampletime = AVAudioFramePosition(Int(sampleRate * Double(value)))
let length = duration - value
let framestoplay = AVAudioFrameCount(Float(playerTime.sampleRate) * length)
self.stop()
if framestoplay > 1000 {
self.scheduleSegment(audioFile, startingFrame: newsampletime, frameCount: framestoplay, at: nil,completionHandler: nil)
}
}
self.play()
}
However, my function seekTo is not working correctly(I'm printing currentTime before and after the function and it shows always a negative value ~= -0.02). What is the wrong thing I'm doing and can I find a simpler way to change the currentTime of the player?

Answer 1

I ran into same issue. Apparently the framestoplay was always 0, which happened because of sampleRate. The value for playerTime.sampleRate was always 0 in my case.
So,
let framestoplay = AVAudioFrameCount(Float(playerTime.sampleRate) * length)
must be replaced with
let framestoplay = AVAudioFrameCount(Float(sampleRate) * length)