I have a UISceneConfiguration for external screen which is triggered when external display is connected to iOS device. // MARK: UISceneSession Lifecycle @available(iOS 13.0, *) func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration { // Called when a new scene session is being created. // Use this method to select a configuration to create the new scene with. switch connectingSceneSession.role { case .windowApplication: return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role) case .windowExternalDisplay: return UISceneConfiguration(name: "External Screen", sessionRole: connectingSceneSession.role) default: fatalError("Unknown Configuration \(connectingSceneSession.role.rawValue)") } } I display a custom view in the external screen this way in a new UIScene linked to external display. But the problem now is if I also have an AVPlayerViewController in the flow of application, it no longer displays to external screen. I suppose AVPlayerViewController does it's own configuration for external display playback perhaps, but now I have a custom view embedded on external screen it is unable to override it. What do I need to do so that AVPlayerViewController can display content to external screen the way it does normally?

I am trying to use AVAudioEngine for listening to mic samples and playing them simultaneously via external speaker or headphones (assuming they are attached to iOS device). I tried the following using AVAudioPlayerNode and it works, but there is too much delay in the audio playback. Is there a way to hear sound realtime without delay? Why the scheduleBuffer API has so much delay I wonder. var engine: AVAudioEngine! var playerNode: AVAudioPlayerNode! var mixer: AVAudioMixerNode! var audioEngineRunning = false public func setupAudioEngine() { self.engine = AVAudioEngine() let input = engine.inputNode let format = input.inputFormat(forBus: 0) playerNode = AVAudioPlayerNode() engine.attach(playerNode) self.mixer = engine.mainMixerNode engine.connect(self.playerNode, to: self.mixer, format: playerNode.outputFormat(forBus: 0)) engine.inputNode.installTap(onBus: 0, bufferSize: 4096, format: format, block: { buffer, time in self.playerNode.scheduleBuffer(buffer, completionHandler: nil) }) do { engine.prepare() try self.engine.start() audioEngineRunning = true self.playerNode.play() } catch { print("error couldn't start engine") audioEngineRunning = false } }

I am using AVAudioSession with playAndRecord category as follows: private func setupAudioSessionForRecording() { let audioSession = AVAudioSession.sharedInstance() do { try audioSession.setActive(false) try audioSession.setPreferredSampleRate(Double(48000)) } catch { NSLog("Unable to deactivate Audio session") } let options:AVAudioSession.CategoryOptions = [.allowAirPlay, .mixWithOthers] do { try AVAudioSession.sharedInstance().setCategory(AVAudioSession.Category.playAndRecord, mode: AVAudioSession.Mode.default, options: options) } catch { NSLog("Could not set audio session category \(error)") } do { try audioSession.setActive(true) } catch { NSLog("Unable to activate AudioSession") } } Next I use AVAudioEngine to repeat what I say in the microphone to external speakers (on the TV connected with iPhone using HDMI Cable). //MARK:- AudioEngine var engine: AVAudioEngine! var playerNode: AVAudioPlayerNode! var mixer: AVAudioMixerNode! var audioEngineRunning = false public func setupAudioEngine() { self.engine = AVAudioEngine() engine.connect(self.engine.inputNode, to: self.engine.outputNode, format: nil) do { engine.prepare() try self.engine.start() } catch { print("error couldn't start engine") } audioEngineRunning = true } public func stopAudioEngine() { engine.stop() audioEngineRunning = false } The issue is I hear some kind of reverb/humming noise after I speak for a few seconds that keeps getting amplified and repeated. If I use a RemoteIO unit instead, no such noise comes out of speakers. I am not sure if my setup of AVAudioEngine is correct. I have tried all kinds of AVAudioSession configuration but nothing changes. The link to sample audio with background speaker noise is posted [here] in the Stackoverflow forum (https://stackoverflow.com/questions/72170548/echo-when-using-avaudioengine-over-hdmi#comment127514327_72170548)

I see AVPlayerViewController automatically hides video preview on iOS device the moment it detects external display. I want to present video preview on external display as well as on iOS device at the same time. The audio should be routed to external screen via HDMI and not playback on iOS device. Is it possible to do this using standard APIs? I could think of a couple of ways mentioned below and would like to hear from AVFoundation team and others what is recommended or the way out: Create two AVPlayerViewController and two AVPlayers. One of it is attached to externalScreen window, and both display same local video file. Audio would be muted for the playerController displaying video on iOS device. Some play/pause/seek syncing code is required to sync both the players. Use only one AVPlayerViewController that airplays to external screen. Attach AVPlayerItemVideoOutput to the playerItem and intercept video frames and display them using Metal/CoreImage on the iOS device. Use two AVPlayerLayer and add them to external and device screen. Video frames will be replicated to both external screen and iOS device , but not sure if it is possible to route audio only to external screen via HDMI but muted locally.

I display my view to external display using UIScene as follows by selecting an appropriate UISceneConfiguration: // MARK: UISceneSession Lifecycle     @available(iOS 13.0, *)     func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {         // Called when a new scene session is being created.         // Use this method to select a configuration to create the new scene with.        // return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)         // This is not necessary; however, I found it useful for debugging                switch connectingSceneSession.role {                    case  .windowApplication:                        return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)                    case .windowExternalDisplay:                        return UISceneConfiguration(name: "External Screen", sessionRole: connectingSceneSession.role)                    default:                        fatalError("Unknown Configuration \(connectingSceneSession.role.rawValue)")                    }     } The above API is called automatically when external screen is connected/disconnected. My question is whether there is anyway or API that disables/enables external screen display at runtime (without user disconnecting the HDMI cable)?

I have a UITableViewController with a grouped table view. No matter what I try, I can't match dark mode colors of native Settings app of iOS 14. I tried the following: self.tableView.backgroundColor = UIColor.systemGroupedBackground And in cellForItemAtIndexPath, I set cell.backgroundColor = UIColor.secondarySystemGroupedBackground This matches colors for light mode but not for dark mode.

I see there is a deprecation warning when using detailTextLabel of UITableViewCell. @available(iOS, introduced: 3.0, deprecated: 100000, message: "Use UIListContentConfiguration instead, this property will be deprecated in a future release.") open var detailTextLabel: UILabel? { get } // default is nil. label will be created if necessary (and the current style supports a detail label). But it is not clear how to use UIListContentConfiguration to support detailTextLabel that is on the right side of the cell. I only see secondaryText in UIListContentConfiguration that is always displayed as a subtitle. How does one use UIListContentConfiguration as a replacement?

I have a RemoteIO unit that successfully playbacks the microphone samples in realtime via attached headphones. I need to get the same functionality ported using AVAudioEngine, but I can't seem to make a head start. Here is my code, all I do is connect inputNode to playerNode which crashes. var engine: AVAudioEngine! var playerNode: AVAudioPlayerNode! var mixer: AVAudioMixerNode! var engineRunning = false private func setupAudioSession() { var options:AVAudioSession.CategoryOptions = [.allowBluetooth, .allowBluetoothA2DP] do { try AVAudioSession.sharedInstance().setCategory(AVAudioSession.Category.playAndRecord, mode: AVAudioSession.Mode.default, options: options) try AVAudioSession.sharedInstance().setAllowHapticsAndSystemSoundsDuringRecording(true) } catch { MPLog("Could not set audio session category") } let audioSession = AVAudioSession.sharedInstance() do { try audioSession.setActive(false) try audioSession.setPreferredSampleRate(Double(44100)) } catch { print("Unable to deactivate Audio session") } do { try audioSession.setActive(true) } catch { print("Unable to activate AudioSession") } } private func setupAudioEngine() { self.engine = AVAudioEngine() self.playerNode = AVAudioPlayerNode() self.engine.attach(self.playerNode) engine.connect(self.engine.inputNode, to: self.playerNode, format: nil) do { try self.engine.start() } catch { print("error couldn't start engine") } engineRunning = true } But starting AVAudioEngine causes a crash: libc++abi: terminating with uncaught exception of type NSException *** Terminating app due to uncaught exception 'com.apple.coreaudio.avfaudio', reason: 'required condition is false: inDestImpl->NumberInputs() > 0 || graphNodeDest->CanResizeNumberOfInputs()' terminating with uncaught exception of type NSException How do I get realtime record and playback of mic samples via headphones working?

The screenshot says all, it's a very irritating issue in XCode where for many builtin symbols, on selection it shows "Cut, Copy,..." instead of "Jump to Definition". Happens most often when jumping from Swift to Objective C symbols. Wondering if there is any fix?

I have a strange crash on iOS device (EXC_BAD_INSTRUCTION). I have a custom UIControl called ScrollingScrubber and all it has is a UIScrollView, and it fires .valueChanged events when user is scrolling. That's where sometimes the crash happens and I have no idea how to debug it further. var value:CGFloat = 0 override open func beginTracking(_ touch: UITouch, with event: UIEvent?) -> Bool { isUserDragging = scroller.isDragging if isUserDragging { sendActions(for: .editingDidBegin) } return isUserDragging } override open func continueTracking(_ touch: UITouch, with event: UIEvent?) -> Bool { value = (scroller.contentOffset.y + scroller.contentInset.top)/(scroller.contentSize.height) sendActions(for: .valueChanged) //It sometimes crashes here with EXC_BAD_INSTRUCTION, why????? return true }

Hourly sales data is not updated in appstoreconnect for the past 3 days. Two days ago, the same website running on different devices were showing different hourly sales figures and now they all show zero sales. Is it a problem on client side or a server outage?

I have an AVComposition playback via AVPlayer where AVComposition has multiple audio tracks with audioMix applied. My question is how is it possible to compute audio meter values for the audio playing back through AVPlayer? Using MTAudioProcessingTap it seems you can only get callback for one track at a time. But if that route has to be used, it's not clear how to get sample values of all the audio tracks at a given time in a single callback?

I have a subclass of UIScrollView called MyScrollView. There is a subview called contentViewinside MyScrollView. The width constraint is set to be the contentSize of MyScrollView. private func setupSubviews() { contentView = ContentView() contentView.backgroundColor = UIColor.blue contentView.translatesAutoresizingMaskIntoConstraints = false contentView.isUserInteractionEnabled = true self.addSubview(contentView) contentView.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true contentView.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true contentView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true contentView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true // create contentView's Width and Height constraints cvWidthConstraint = contentView.widthAnchor.constraint(equalToConstant: 0.0) cvHeightConstraint = contentView.heightAnchor.constraint(equalToConstant: 0.0) // activate them cvWidthConstraint.isActive = true cvHeightConstraint.isActive = true cvWidthConstraint.constant = myWidthConstant //<--- problem here if myWidthConstant is very high, such as 512000 cvHeightConstraint.constant = frame.height contentView.layoutIfNeeded() } The problem is if I set cvWidthConstraint.constant to a very high value such as 521000, I get a warning: This NSLayoutConstraint is being configured with a constant that exceeds internal limits. A smaller value will be substituted, but this problem should be fixed. Break on BOOL _NSLayoutConstraintNumberExceedsLimit(void) to debug. This will be logged only once. This may break in the future. I wonder how does one set UIScrollView content size to be very high values?

I wrote the following Metal Core Image Kernel to produce constant red color. extern "C" float4 redKernel(coreimage::sampler inputImage, coreimage::destination dest) {     return float4(1.0, 0.0, 0.0, 1.0); } And then I have this in Swift code: class CIMetalRedColorKernel: CIFilter {     var inputImage:CIImage?     static var kernel:CIKernel = { () -> CIKernel in         let bundle = Bundle.main         let url = bundle.url(forResource: "Kernels", withExtension: "ci.metallib")!         let data = try! Data(contentsOf: url)         return try! CIKernel(functionName: "redKernel", fromMetalLibraryData: data)     }()     override var outputImage: CIImage? {         guard let inputImage = inputImage else {             return nil         }         let dod = inputImage.extent         return CIMetalTestRenderer.kernel.apply(extent: dod, roiCallback: { index, rect in             return rect         }, arguments: [inputImage])     } } As you can see, the dod is given to be the extent of the input image. But when I run the filter, I get a whole red image beyond the extent of the input image (DOD), why? I have multiple filters chained together and the overall size is 1920x1080. Isn't the red filter supposed to run only for DOD rectangle passed in it and produce clear pixels for anything outside the DOD?

I dragged a group of files from one XCode project to another. I noticed XCode copied the whole project folder instead of the selected group of files. I immediately selected the copied project folder and deleted it, and selected "Remove References only" as I had a bad experience earlier where I chose to delete the files (in which case the files got deleted from the original project). But now when I commit the changes to git, it shows me list of 1300 files from the original project to commit, even though they are not there in the project. I search the all the project subfolders and those files are no where in the project. What do I do for git to forget those files?