Slow to display camera.

[yummypets]

Slow to display camera.

[s4cha]

PR here : #26
I'll take time tomorrow to issue a new version with the fix :)

[s4cha]

https://github.com/Yummypets/YPImagePicker/releases/tag/2.5.1
:)

[s4cha]

@viktorgardart,
First thanks a ton for taking the time to open an issue for this.
I had the issue before on and off, on my side the issue was quite hard to reproduce, it seemed to happen more often in release configuration.
I came to the conclusion that this was thread related, something like a data race for instance.
This would explain the freeze and the randomness of the issue.
This is quite annoying :/
I'm going to look into it again but if you want to instrument as well I could definitely use some help :) We'll report our findings here .

Cheers,

[s4cha]

@viktorgardart oO i'Ve found :) thanks so much for bringing this up I had gave up earlier :)

[s4cha]

will post the fix

[s4cha]

diff --git a/Source/Camera/YPCameraVC.swift b/Source/Camera/YPCameraVC.swift
index 2c82c30..8ee1238 100644
--- a/Source/Camera/YPCameraVC.swift
+++ b/Source/Camera/YPCameraVC.swift
@@ -13,7 +13,7 @@ import Photos
 public class YPCameraVC: UIViewController, UIGestureRecognizerDelegate, PermissionCheckable {
     
     public var didCapturePhoto: ((UIImage) -> Void)?
-    private let sessionQueue = DispatchQueue(label: "YPCameraVCSerialQueue")
+    private let sessionQueue = DispatchQueue(label: "YPCameraVCSerialQueue", qos: .background)
     let session = AVCaptureSession()
     var device: AVCaptureDevice? {
         return videoInput?.device
@@ -49,21 +49,27 @@ public class YPCameraVC: UIViewController, UIGestureRecognizerDelegate, Permissi
     
     public override func viewDidAppear(_ animated: Bool) {
         super.viewDidAppear(animated)
+        refreshFlashButton()
+    }
+    
+    func tryToSetupPreview() {
         if !isPreviewSetup {
             setupPreview()
             isPreviewSetup = true
         }
-        refreshFlashButton()
     }
     
     func setupPreview() {
         let videoLayer = AVCaptureVideoPreviewLayer(session: session)
-        videoLayer.frame = v.previewViewContainer.bounds
-        videoLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
-        v.previewViewContainer.layer.addSublayer(videoLayer)
-        let tapRecognizer = UITapGestureRecognizer(target: self, action: #selector(focusTapped(_:)))
-        tapRecognizer.delegate = self
-        v.previewViewContainer.addGestureRecognizer(tapRecognizer)
+        
+        DispatchQueue.main.async {
+            videoLayer.frame = self.v.previewViewContainer.bounds
+            videoLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
+            self.v.previewViewContainer.layer.addSublayer(videoLayer)
+            let tapRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.focusTapped(_:)))
+            tapRecognizer.delegate = self
+            self.v.previewViewContainer.addGestureRecognizer(tapRecognizer)
+        }
     }
     
     private func setupCaptureSession() {
@@ -120,6 +126,7 @@ public class YPCameraVC: UIViewController, UIGestureRecognizerDelegate, Permissi
                     self.session.stopRunning()
                 case .authorized:
                     self.session.startRunning()
+                    self.tryToSetupPreview()
                 }
             }
         }

[s4cha]

Something that is very strange though concerning the dispatchQueue

DispatchQueue(label: "YPCameraVCSerialQueue") // SLOW
DispatchQueue(label: "YPCameraVCSerialQueue", qos: .userInitiated) // SLOW
DispatchQueue(label: "YPCameraVCSerialQueue", qos: .userInteractive) // SLOW
DispatchQueue(label: "YPCameraVCSerialQueue", qos: .utility) // SLOW
DispatchQueue(label: "YPCameraVCSerialQueue", qos: .default) // SLOW
DispatchQueue(label: "YPCameraVCSerialQueue", qos: .background) // FAST

From what I believed, userInteractive should've been the fastest but somehow that's not the case :/

The second part of the fix is doing let videoLayer = AVCaptureVideoPreviewLayer(session: session)
in the session queue.

[viktorgardart]

Thanks a lot for the quick reply, I’ll check out the fix later today/tomorrow! 🙂

_{Sent with GitHawk}

[viktorgardart]

Works! 💃 Thanks @s4cha

[viktorgardart]

Or.. hmm 🤔
It went from always being slow to being slow sometimes. 😕

[s4cha]

mm that's V weird :/ not happening anymore on my side what device are you testing on?

[viktorgardart]

The same device as previously, but haven't seen it since.. Closing for now and reopening if I find anything new!