How to display progress of AVPlayer playback of audio - ios

Question

I'm building a music app that will have a feed of posts that contain url to music files. When a cell in UITableView becomes fully visible playback of a corresponding music track starts.
This is a layout I have now.
Waveform is being generated by a server and I receive its data as an array of type [Float].
Complete waveform is a UIView that has a bar subviews with a height of a corresponding item from array from a server.
Here is a WaveformPlot Source:
class WaveformPlot: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
//MARK: Populate plot with data from server response
func populateWithData(from dataSet: [Float]){
DispatchQueue.main.async {
var offset: CGFloat = 0
for index in 0..<dataSet.count {
let view = UIView(frame: CGRect(x: offset,
y: self.frame.height / 2,
width: self.frame.width / CGFloat(dataSet.count),
height: -(CGFloat)((dataSet[index]) / 3)))
let view2 = UIView(frame: CGRect(x: offset,
y: self.frame.height / 2,
width: self.frame.width / CGFloat(dataSet.count),
height: (CGFloat)((dataSet[index]) / 3)))
//Upper row of bars adjust
view.backgroundColor = UIColor.orange
view.layer.borderColor = UIColor.black.cgColor
view.layer.borderWidth = 0.25
view.clipsToBounds = true
view.round(corners: [.topLeft, .topRight], radius: 2)
//Lower row of bars adjust
view2.backgroundColor = UIColor.orange
view2.layer.borderColor = UIColor.black.cgColor
view2.layer.borderWidth = 0.25
view2.round(corners: [.bottomLeft, .bottomRight], radius: 2)
view2.layer.opacity = 0.6
self.addSubview(view)
self.addSubview(view2)
offset += self.frame.width / CGFloat(dataSet.count)
}
//Create gradient
let gradientView = UIView(frame: CGRect(x: 0, y: self.frame.height / 2, width: self.frame.width, height: -self.frame.height / 2))
let gradientLayer = CAGradientLayer()
gradientLayer.frame = gradientView.bounds
gradientLayer.colors = [UIColor.black.cgColor, UIColor.clear.cgColor]
gradientView.layer.insertSublayer(gradientLayer, at: 0)
gradientView.layer.opacity = 0.9
self.addSubview(gradientView)
}
}
func clearPlot(){
for item in self.subviews{
item.removeFromSuperview()
}
}
}
Source of a player I've implemented.
class StreamMusicPlayer: AVPlayer {
private override init(){
super.init()
}
static var currentItemURL: String?
static var shared = AVPlayer()
static func playItem(musicTrack: MusicTrack) {
StreamMusicPlayer.shared = AVPlayer(url: musicTrack.trackURL)
StreamMusicPlayer.currentItemURL = musicTrack.trackURL.absoluteString
StreamMusicPlayer.shared.play()
}
}
extension AVPlayer {
var isPlaying: Bool {
return rate != 0 && error == nil
}
}
The problem is that it is required to show progress of a track currently playing in a corresponding cell waveform.
It has to be similar to this:
What approach should i choose? I'm out of ideas how to implement this.
Any help appreciated.

Answer 1

The method described by war4l is a way of showing the progress. But to actually get the progress you need to add a periodic time observer. Something like this.
let interval = CMTime(value: 1, timescale: 2)
StreamMusicPlayer.shared.addPeriodicTimeObserver(forInterval: interval, queue: DispatchQueue.main, using: { (progressTime) in
let seconds = CMTimeGetSeconds(progressTime)
if let duration = self.StreamMusicPlayer.shared.currentItem?.duration {
let totalDurationInSeconds = CMTimeGetSeconds(duration)
// Now you have current time and the duration so can display this somehow
}
})