Add custom controls to AVPlayer in swift

here I add the points , you need to customize based on your need.

Step-1

initially hide your AVPlayer controls,

 YourAVPlayerViewController.showsPlaybackControls = false

Step-2

create the structure like

one label for current Duration, One label for overall Duration, one UIbutton for pause and play your current player and one UISlider for seek The video.

step-3

initially close the simple steps.

first stop and play the player using button action , currentPlayer is your AVPlayer name.

@IBAction func handlePlayPauseButtonPressed(_ sender: UIButton) {
   //  sender.isSelected ?  currentPlayer.pause() :   currentPlayer.play()
    if sender.isSelected {
        currentPlayer.pause()
    }
    else {
        currentPlayer.play()
    }
}

second set the video duration, as like

    let duration : CMTime = currentPlayer.currentItem!.asset.duration
    let seconds : Float64 = CMTimeGetSeconds(duration)

    lblOverallDuration.text = self.stringFromTimeInterval(interval: seconds)

third set the player current time to current duration label

    let duration : CMTime = currentPlayer.currentTime()
    let seconds : Float64 = CMTimeGetSeconds(duration)

    lblcurrentText.text = self.stringFromTimeInterval(interval: seconds)

the following method is convert from NSTimeinterval to HH:MM:SS

func stringFromTimeInterval(interval: TimeInterval) -> String {

    let interval = Int(interval)
    let seconds = interval % 60
    let minutes = (interval / 60) % 60
    let hours = (interval / 3600)
    return String(format: "%02d:%02d:%02d", hours, minutes, seconds)
}

finally we go for slider control for calulate the seek time

_playheadSlider.addTarget(self, action: #selector(self.handlePlayheadSliderTouchBegin), for: .touchDown)
_playheadSlider.addTarget(self, action:    #selector(self.handlePlayheadSliderTouchEnd), for: .touchUpInside)
_playheadSlider.addTarget(self, action: #selector(self.handlePlayheadSliderTouchEnd), for: .touchUpOutside)
_playheadSlider.addTarget(self, action: #selector(self.handlePlayheadSliderValueChanged), for: .valueChanged)

lets we go for action, initially when touchbegin is start then stop the player

handlePlayheadSliderTouchBegin

@IBAction func handlePlayheadSliderTouchBegin(_ sender: UISlider) {
currentPlayer.pause()
}

set the current item label for calculate the sender.value * CMTimeGetSeconds(currentPlayer.currentItem.duration)

@IBAction func handlePlayheadSliderValueChanged(_ sender: UISlider) {

        let duration : CMTime = currentPlayer.currentItem!.asset.duration
     let seconds : Float64 = CMTimeGetSeconds(duration) * sender.value
 //   var newCurrentTime: TimeInterval = sender.value * CMTimeGetSeconds(currentPlayer.currentItem.duration)
lblcurrentText.text = self.stringFromTimeInterval(interval: seconds)
   }

finally move the player based on seek

 @IBAction func handlePlayheadSliderTouchEnd(_ sender: UISlider) {

  let duration : CMTime = currentPlayer.currentItem!.asset.duration
var newCurrentTime: TimeInterval = sender.value * CMTimeGetSeconds(duration)
var seekToTime: CMTime = CMTimeMakeWithSeconds(newCurrentTime, 600)
currentPlayer.seek(toTime: seekToTime)
}

In addition to Anbu.Karthik's answer, the slider handing can be handled better in a single function like below:

slider.addTarget(self, action: #selector(self.handlePlayheadSliderValueChanged(sender:event:)), for: .valueChanged)

Slider Value Change:

Note switch cases handling all phases of slider event

@objc func handlePlayheadSliderValueChanged(sender: UISlider, event: UIEvent) {
    if let duration: CMTime = player?.currentItem?.asset.duration {
        let newCurrentTime: Float64 = CMTimeGetSeconds(duration) * Double(sender.value)
        videoLengthLabel.text = self.stringFromTimeInterval(interval: newCurrentTime)
        if let touchEvent = event.allTouches?.first {
            switch (touchEvent.phase) {
            case .began:
                // on slider touch begin
                pauseVideo()
                break
            case .moved:
                // on slider movement
                let seekToTime: CMTime = CMTimeMakeWithSeconds(newCurrentTime, preferredTimescale: 600)
                player?.seek(to: seekToTime, completionHandler: { (completedSeek) in
                    // any additional operation upon seek completion
                })
                break
            case .ended:
                // on slider touch end (finger lift)
                playVideo()
                break
            default:
                break
            }
        }
    }
}