Enables smooth frame-by-frame scrubbing (in both directions) – similar to Apple's applications.

AVPlayer+Scrubbing.swift

public enum Direction {
    case forward
    case backward
}

internal var player: AVPlayer?

private var isSeekInProgress = false
private var chaseTime = kCMTimeZero
private var preferredFrameRate: Float = 23.98

public func seek(to time: CMTime) {
    seekSmoothlyToTime(newChaseTime: time)
}

public func stepByFrame(in direction: Direction) {
    let frameRate = preferredFrameRate
        ?? player?.currentItem?.tracks
            .first(where: { $0.assetTrack.mediaType == .video })?
            .currentVideoFrameRate
        ?? -1

    let time = player?.currentItem?.currentTime() ?? kCMTimeZero
    let seconds = Double(1) / Double(frameRate)
    let timescale = Double(seconds) / Double(time.timescale) < 1 ? 600 : time.timescale
    let oneFrame = CMTime(seconds: seconds, preferredTimescale: timescale)
    let next = direction == .forward
        ? CMTimeAdd(time, oneFrame)
        : CMTimeSubtract(time, oneFrame)

    seekSmoothlyToTime(newChaseTime: next)
}

private func seekSmoothlyToTime(newChaseTime: CMTime) {
    if CMTimeCompare(newChaseTime, chaseTime) != 0 {
        chaseTime = newChaseTime

        if !isSeekInProgress {
            trySeekToChaseTime()
        }
    }
}

private func trySeekToChaseTime() {
    guard player?.status == .readyToPlay else { return }
    actuallySeekToTime()
}

private func actuallySeekToTime() {
    isSeekInProgress = true
    let seekTimeInProgress = chaseTime

    player?.seek(to: seekTimeInProgress, toleranceBefore: kCMTimeZero, toleranceAfter: kCMTimeZero) { [weak self] _ in
        guard let `self` = self else { return }

        if CMTimeCompare(seekTimeInProgress, self.chaseTime) == 0 {
            self.isSeekInProgress = false
        } else {
            self.trySeekToChaseTime()
        }
    }
}

Thank you!
This works but need to update few things:

• kCMTimeZero => CMTime.Zero
• Direction enum and stepByFrame function are not used

    
    lazy internal var player: AVPlayer? = { return videoView.player }()
    
    private var isSeekInProgress = false
    private var chaseTime = CMTime.zero
    
    public func seek(to time: CMTime) {
        seekSmoothlyToTime(newChaseTime: time)
    }
    
    private func seekSmoothlyToTime(newChaseTime: CMTime) {
        if CMTimeCompare(newChaseTime, chaseTime) != 0 {
            chaseTime = newChaseTime
            
            if !isSeekInProgress {
                trySeekToChaseTime()
            }
        }
    }
    
    private func trySeekToChaseTime() {
        guard player?.status == .readyToPlay else { return }
        actuallySeekToTime()
    }
    
    private func actuallySeekToTime() {
        isSeekInProgress = true
        let seekTimeInProgress = chaseTime
        
        player?.seek(to: seekTimeInProgress, toleranceBefore: .zero, toleranceAfter: .zero) { [weak self] _ in
            guard let `self` = self else { return }
            
            if CMTimeCompare(seekTimeInProgress, self.chaseTime) == 0 {
                self.isSeekInProgress = false
            } else {
                self.trySeekToChaseTime()
            }
        }
    }

Its a convenience function so you don't need all that faff in your own code ;)
The CMTime stuff agreed, needs to be updated. I actually have other improvements to this in the real code anyway. This was just a nice starter for anyone having the same problem. Thanks anyway.

Also, you've introduced a dependency videoView. A gist should be considered drop-in code only.

Thank you for this! I was looking for some way to smooth out my seeking. This is working brilliantly.

Thank you for this! I was looking for some way to smooth out my seeking. This is working brilliantly.

Great! 👍

I have scrubbing issue .My salider is jumpy I implemented your code but still same issue .
Can you help me ?

import UIKit
import AVFoundation
import UIKit
import AVKit
import CoreMedia
class ViewController: UIViewController {

public enum Direction {
    case forward
    case backward
}
private var isSeekInProgress = false
private var chaseTime = CMTime.zero
private var preferredFrameRate: Float = 23.98







 var timeObserverToken: Any?
let playerLayer: AVPlayerLayer = AVPlayerLayer()

var videoPlayer: AVPlayer?
@IBOutlet weak var VedioView: UIView!
@IBOutlet weak var videoSlider: UISlider!
override func viewDidLoad() {

    VedioView.backgroundColor = .red
    let videoAsset: [AVAsset] = [
    AVAsset( url: Bundle.main.url(forResource: "1-2", withExtension: "mp4")! ),
    AVAsset( url: Bundle.main.url(forResource: "2-3", withExtension: "mp4")! ),
    AVAsset( url: Bundle.main.url(forResource: "3-4", withExtension: "mp4")! ),
    AVAsset( url: Bundle.main.url(forResource: "4-5", withExtension: "mp4")! ),
    AVAsset( url: Bundle.main.url(forResource: "5-1", withExtension: "mp4")! )]



   
     
    let videoComposition = AVMutableComposition()
    var playerItem: AVPlayerItem!
   
    var lastTime: CMTime = CMTime.zero

    let videoCompositionTrack = videoComposition.addMutableTrack(withMediaType: AVMediaType.video, preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
    for clipIndex in videoAsset {

        do {
            try videoCompositionTrack?.insertTimeRange(CMTimeRangeMake(start: CMTime.zero, duration: clipIndex.duration),
                                                       of: clipIndex.tracks(withMediaType: AVMediaType.video)[0] ,
                                                       at: lastTime)
            
            lastTime = CMTimeAdd(lastTime, clipIndex.duration)
            
            
        } catch {
            print("Failed to insert track")
        }
    }
    playerItem = AVPlayerItem(asset: videoComposition)
    let timeRange = CMTimeRangeMake(start: CMTime.zero, duration: CMTime(seconds:playerItem.duration.seconds, preferredTimescale: 1))
    
    videoComposition.scaleTimeRange(timeRange, toDuration: CMTimeMultiplyByFloat64(playerItem.duration, multiplier: Float64(0.5)))
    
   videoPlayer = AVPlayer(playerItem: playerItem)
   
    playerLayer.player = videoPlayer
    playerLayer.frame = self.VedioView.bounds //bounds of
    playerLayer.videoGravity = .resizeAspectFill
    self.VedioView.layer.addSublayer(playerLayer)
    videoPlayer?.volume = 0.0
    videoPlayer?.play()
    
   addPeriodicTimeObserver()
   NotificationCenter.default.addObserver(self,
         selector: #selector(playerItemDidReachEnd(notification:)),
         name: .AVPlayerItemDidPlayToEndTime,
         object: videoPlayer?.currentItem)
   videoSlider.addTarget(self, action: #selector(handleSliderChange), for: .valueChanged)
    videoSlider.addTarget(self, action: #selector(onSlidertouch), for: .touchDown)
    videoSlider.addTarget(self, action: #selector(onSlidertouchUp), for:.touchUpInside )
    videoSlider.addTarget(self, action: #selector(saliderMoving), for: .touchUpOutside )
}
@objc func playerItemDidReachEnd(notification: Notification) {
   if let playerItem = notification.object as? AVPlayerItem {
         playerItem.seek(to: CMTime.zero, completionHandler: nil)
    videoPlayer?.play()
     }
  
}
@IBAction func saliderAction(_ sender: Any) {
}
@objc func onSlidertouch(){
    
    removePeriodicTimeObserver()
   // timer.invalidate()
    videoPlayer?.pause()
}
@objc func onSlidertouchUp(){
  
    addPeriodicTimeObserver()

    videoPlayer?.play()
}
@objc func saliderMoving(){
addPeriodicTimeObserver()

    videoPlayer?.play()
         
}
func removePeriodicTimeObserver() {
       if let timeObserverToken = timeObserverToken {
        videoPlayer?.removeTimeObserver(timeObserverToken)
           self.timeObserverToken = nil
       }
   }
@objc func handleSliderChange() {
    if let duration = videoPlayer?.currentItem?.duration {
                      let totalSeconds = CMTimeGetSeconds(duration)
                    
                      let value = Float64(videoSlider.value) * totalSeconds
                 
        let seekTime = CMTime(value: Int64(value), timescale: CMTimeScale(1))

// videoPlayer.seek(to: seekTime, completionHandler: { (completedSeek) in
//
//
// })
seek( to: seekTime)

              }
        
    }

func addPeriodicTimeObserver() {

         // Notify every half second
         let interval = CMTime(value: 1, timescale: 100)
timeObserverToken =  videoPlayer?.addPeriodicTimeObserver(forInterval: interval, queue: DispatchQueue.main, using: { (progressTime) in
    let seconds = CMTimeGetSeconds(progressTime)
              
    if let duration = self.videoPlayer?.currentItem?.duration {
                            let durationSeconds = CMTimeGetSeconds(duration)
                      
        let currentTime = Double((self.videoPlayer?.currentTime().seconds)!)
 
self.videoSlider.value = Float(seconds / durationSeconds)
}
    })
     }

@IBAction func pLAY(_ sender: UIButton) {
    videoPlayer?.play()
}
@IBAction func pAUSE(_ sender: UIButton) {
    videoPlayer?.pause()
}

public func seek(to time: CMTime) {
seekSmoothlyToTime(newChaseTime: time)
}

 public func stepByFrame(in direction: Direction) {
     let frameRate = preferredFrameRate
        ?? videoPlayer?.currentItem?.tracks
            .first(where: { $0.assetTrack?.mediaType == .video })?
             .currentVideoFrameRate
         ?? -1

    let time = videoPlayer?.currentItem?.currentTime() ?? CMTime.zero
     let seconds = Double(1) / Double(frameRate)
     let timescale = Double(seconds) / Double(time.timescale) < 1 ? 600 : time.timescale
     let oneFrame = CMTime(seconds: seconds, preferredTimescale: timescale)
     let next = direction == .forward
         ? CMTimeAdd(time, oneFrame)
         : CMTimeSubtract(time, oneFrame)

     seekSmoothlyToTime(newChaseTime: next)
 }

 private func seekSmoothlyToTime(newChaseTime: CMTime) {
     if CMTimeCompare(newChaseTime, chaseTime) != 0 {
         chaseTime = newChaseTime

         if !isSeekInProgress {
             trySeekToChaseTime()
         }
     }
 }

 private func trySeekToChaseTime() {
    guard videoPlayer?.status == .readyToPlay else { return }
     actuallySeekToTime()
 }

 private func actuallySeekToTime() {
     isSeekInProgress = true
     let seekTimeInProgress = chaseTime

    videoPlayer?.seek(to: seekTimeInProgress, toleranceBefore: CMTime.zero, toleranceAfter: CMTime.zero) { [weak self] _ in
         guard let `self` = self else { return }

         if CMTimeCompare(seekTimeInProgress, self.chaseTime) == 0 {
             self.isSeekInProgress = false
         } else {
             self.trySeekToChaseTime()
         }
     }
 }

}

//This is my code which have jumpy Scrubbing

@Talhasahi Did you solve your issue? I have the same problem when I'm using AVComposition.
Btw. looking briefly at your code:
CMTime(seconds:playerItem.duration.seconds, preferredTimescale: 1) this might fail if the duration is not exactly seconds as the preferredTimescale is 1 (ie. duration of 3.5 seconds will fail)

https://stackoverflow.com/a/17331242/2742007

avPlayer.currentItem?.step(byCount: isForward ? 1 : -1)

https://developer.apple.com/documentation/avfoundation/avplayeritem/1387968-step

https://stackoverflow.com/a/17331242/2742007

avPlayer.currentItem?.step(byCount: isForward ? 1 : -1)

https://developer.apple.com/documentation/avfoundation/avplayeritem/1387968-step

This is not relevant I'm afraid. Or more importantly it's incomplete. If you read (or even try) that API out yourself, you'll note that it's not performant in most user-driven cases and cannot chase smoothly. This is because it doesn't cancel previous seeks.

The provided example solves this problem for high performance cases. The API you're suggesting is fine for non-interactive scenarios though 👍

I invite you to have a look at my related comment on Stack Overflow for how smooth scrubbing can be achieved, providing content can support stepping.

Our implementation, which can be seen and tested in our player library, is currently at least on par with AVPlayerViewController implementation (sometimes achieveing better results), whether the content supports stepping (frame-by-frame), I-frames or neither.

Thanks for sharing. I’ll have to give this a shot. I read your post and it sounds similar. One thing I’m curious about is not cancelling pending. This was actually recommended by someone on the AV team but I think your approach is different in that you use very different tolerances. But I’ll give it a shot because as you mentioned, one of the issues generally for getting fast almost frame-by-frame seeking depends on how it was encoded. But perhaps your solution has better more consistent results. If I get around to testing ill let you know either way 👍 Thanks again! Shaps

Thanks for sharing. I’ll have to give this a shot. I read your post and it sounds similar. One thing I’m curious about is not cancelling pending. This was actually recommended by someone on the AV team but I think your approach is different in that you use very different tolerances. But I’ll give it a shot because as you mentioned, one of the issues generally for getting fast almost frame-by-frame seeking depends on how it was encoded. But perhaps your solution has better more consistent results. If I get around to testing ill let you know either way 👍 Thanks again! Shaps

Side note btw regarding AVPlayerController. I believe at one point I discovered that actually they use the thumbnail generator to improve the perceived responsiveness. I did this in another product (simple video editor) alongside the code above and it had a drastic impact on the UX. but if your approach improves the actual seeking as well then that just another huge plus.

This was actually recommended by someone on the AV team but I think your approach is different in that you use very different tolerances.

I guess this could be recommended if you want to avoid downloading too many segments while seeking, but this of course depends on the desired user experience. As far as I can see AVPlayerViewController nowadays seem to avoid seek cancellation, probably as described in Apple dedicated Q&A article.

Side note btw regarding AVPlayerController. I believe at one point I discovered that actually they use the thumbnail generator to improve the perceived responsiveness.

Note sure if they use AVAssetImageGenerator directly but if HLS streams contain I-frames the player surely uses them (even without changing the actual player speed to values > 2, which I initially thought might be required).

BTW you can easily test the behavior our implementation achieves by installing our demo app from TestFlight. The first demo tab has a lot of different streams from several sources (with various encodings and packagings), including the standard Apple test streams. You can also use the demo to compare the behavior we obtain vs. the one provided by the system player UI since we also have included the vanilla system experience in our demo as well (2nd tab).

Oh that’s amazing thanks! Unfortunately your beta isn’t accepting lol but I trust you.

Oh that’s amazing thanks! Unfortunately your beta isn’t accepting lol but I trust you.

Should be fixed now, sorry, there was no recent build enabled for external testing 😇

👍👍