I've been using CGWindowListCreateImage which automatically creates an image with the size of the captured window.
But SCScreenshotManager.captureImage(contentFilter:configuration:) always creates images with the width and height specified in the provided SCStreamConfiguration. I could be setting the size explicitly by reading SCWindow.frame or SCContentFilter.contentRect and multiplying the width and height by SCContentFilter.pointPixelScale , but it won't work if I want to keep the window shadow with SCStreamConfiguration.ignoreShadowsSingleWindow = false.
Is there a way and what's the best way to take full-resolution screenshots of the correct size?
import Cocoa
import ScreenCaptureKit
class ViewController: NSViewController {
@IBOutlet weak var imageView: NSImageView!
override func viewDidAppear() {
imageView.imageScaling = .scaleProportionallyUpOrDown
view.wantsLayer = true
view.layer!.backgroundColor = .init(red: 1, green: 0, blue: 0, alpha: 1)
Task {
let windows = try await SCShareableContent.excludingDesktopWindows(false, onScreenWindowsOnly: true).windows
let window = windows[0]
let filter = SCContentFilter(desktopIndependentWindow: window)
let configuration = SCStreamConfiguration()
configuration.ignoreShadowsSingleWindow = false
configuration.showsCursor = false
configuration.width = Int(Float(filter.contentRect.width) * filter.pointPixelScale)
configuration.height = Int(Float(filter.contentRect.height) * filter.pointPixelScale)
print(filter.contentRect)
let windowImage = try await SCScreenshotManager.captureImage(contentFilter: filter, configuration: configuration)
imageView.image = NSImage(cgImage: windowImage, size: CGSize(width: windowImage.width, height: windowImage.height))
}
}
}
Explore the integration of media technologies within your app. Discuss working with audio, video, camera, and other media functionalities.
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I'm unable to play music using Musickit.js in the Chrome or Firefox browsers.
Even using the apple guide here: https://js-cdn.music.apple.com/musickit/v1/index.html - I've added my Music Developer Token and song/album url, but it only works in Safari and not in Chrome or Firefox.
I'm unsure if this is a global issue, or if there is something I need to do to enable playback in other browsers, but as it stands it's not working for me.
Thanks for any help in advance!
Hi,It seems like it's pretty easy to consume HTTP Live Streaming content in an iOS app. Unfortunately, I need to consume media from an RTSP server. It seems to me that this is a very similar thing, and that all of the underpinnings for doing it ought to be present in iOS, but I'm having a devil of a time figuring out how to make it work without doing a lot of programming.For starters, I know that there are web-based services that can consume an RTSP stream and rebroadcast it as an HTTP Live Stream that can be easily consumed by the media players in iOS. This won't work for me because my application needs to function in an environment where there is no internet access (it's on a private Wifi network where the only other thing on the network is the device that is serving the RTSP stream).Having read everything I can get my hands on and exploring third-party and open-source solutions, I've compiled the following list of ideas:1. Using an iOS build of the open-source ffmpeg library, which supports RTSP, I've come up with a test app that can receive the RTSP packets, decode them, create UIImages out of the frames, and display those frames on-screen. This provides a crude player, but performance is poor, most likely because ffmpeg can't take advantage of any hardware acceleration. It also doesn't provide me with any way to integrate the video stream into AVFoundation, so I'm on my own as far as saving the stream to a file, transcoding it, etc.2. I know that the AVURLAsset class doesn't directly support the RTSP scheme. Since I have access to the undecoded RTSP packets via ffmpeg, I've thought it should be possible to implement RTSP support myself via a custom NSURLProtocol, essentially fooling AVFoundation into reading those packets as if they originated in a file. I'm not sure if this would work, since the raw packets coming from the RTSP server might lack the headers that would otherwise be present in data being read from a file. I'm not even sure if AVFoundation would recognize my custom protocol.3. If a protocol doesn't work, I've considered that I might be able to implement my own local HTTP Live Streaming server that converts the RTSP packets into an HTTP stream that the media players can read. This sounds like a terribly convoluted solution to the problem, at best, and very difficult at worst.4. Going back to solution (1), if I could speed up the decoding by using some iOS CoreVideo function instead of ffmpeg, this solution might be okay. However, I can't find any documentation for CoreVideo on iOS (Apple only documents it for OS X).5. I'm certainly willing to license a third-party solution if it works well and provides good performance. Unfortunately, everything I've found so far is pretty crummy and mostly just leverages ffmpeg and/or VLC. What is most disappointing to me is that nobody seems to be able or willing to provide a solution that neatly integrates with AVFoundation. I really want to make my RTSP stream available as an AVAsset so I can use it with AVFoundation players and other classes -- I don't want to build an app that relies on custom third-party code for everything.Any ideas, tips, advice would be greatly appreciated.Thanks,Frank
I have a complex CoreImage pipeline which I'm keen to optimise. I'm aware that calling back to the CPU can have a significant impact on the performance - what is the best way to find out where this is happening?
I am using https://developer.apple.com/documentation/applemusicapi/add-tracks-to-a-library-playlist
to add tracks to playlists. This endpoint works fine for all playlists except for collaborative playlists.
For collaborative playlist I get the following 500 error as a response:
"errors": [
{
"id": "<some id>",
"title": "Upstream Service Error",
"detail": "Unable to update tracks",
"status": "500",
"code": "50001"
}
]
}
Steps to reproduce:
Create a playlist in your library.
Use the api to add a song.
Confirm that it works.
Make that same playlist collaborative.
Update the playlist ID in your api request (as making a playlist collaborative changes its id)
Confirm that you get the 500 error.
(This only started happening as of Xcode 26.)
I know macOS and watchOS don't support this property, but all other platforms do (did?) up until I upgraded Xcode. Now when I compile I get this:
Value of type 'AVPlayerItem' has no member 'externalMetadata'
I am trying to use the new SpeechAnalyzer framework in my Mac app, and am running into an issue for some languages.
When I call AssetInstallationRequest.downloadAndInstall() for some languages, it throws an error:
Error Domain=SFSpeechErrorDomain Code=1 "transcription.ar asset not found after attempted download."
The ".ar" appears to be the language code, which in this case was Arabic.
When I call AssetInventory.status(forModules:) before attempting the download, it is giving me a status of "downloading" (perhaps from an earlier attempt?). If this language was completely unsupported, I would expect it to return a status of "unsupported", so I'm not sure what's going on here.
For other languages (Polish, for example) SpeechTranscriber.supportedLocale(equivalentTo:) is returning nil, so that seems like a clearly unsupported language. But I can't tell if the languages I'm trying, like Arabic, are supported and something is going wrong, or if this error represents something I can work around.
Here's the relevant section of code. The error is thrown from downloadAndInstall(), so I never even get as far as setting up the SpeechAnalyzer itself.
private func setUpAnalyzer() async throws {
guard let sourceLanguage else {
throw Error.languageNotSpecified
}
guard let locale = await SpeechTranscriber.supportedLocale(equivalentTo: Locale(identifier: sourceLanguage.rawValue)) else {
throw Error.unsupportedLanguage
}
let transcriber = SpeechTranscriber(locale: locale, preset: .progressiveTranscription)
self.transcriber = transcriber
let reservedLocales = await AssetInventory.reservedLocales
if !reservedLocales.contains(locale) && reservedLocales.count == AssetInventory.maximumReservedLocales {
if let oldest = reservedLocales.last {
await AssetInventory.release(reservedLocale: oldest)
}
}
do {
let status = await AssetInventory.status(forModules: [transcriber])
print("status: \(status)")
if let installationRequest = try await AssetInventory.assetInstallationRequest(supporting: [transcriber]) {
try await installationRequest.downloadAndInstall()
}
}
...
I'm building a UIKit app that reads user's Apple Music library and displays it. In MusicKit there is the Artwork structure which I need to use to display artwork images in the app. Since I'm not using SwiftUI I cannot use the ArtworkImage view that is recommended way of displaying those images but the Artwork structure has a method that returns url for the image which can be used to read the image.
The way I have it setup is really simple:
extension MusicKit.Song {
func imageURL(for cgSize: CGSize) -> URL? {
return artwork?.url(
width: Int(cgSize.width),
height: Int(cgSize.height)
)
}
func localImage(for cgSize: CGSize) -> UIImage? {
guard let url = imageURL(for: cgSize),
url.scheme == "musicKit",
let data = try? Data(contentsOf: url) else {
return nil
}
return .init(data: data)
}
}
Now, everytime I access .artwork property (so a lot of times) the main thread gets blocked and the console output gets bombared with messages like these:
2023-07-26 11:49:47.317195+0200 Plum[998:297199] [Artwork] Failed to create color analysis for artwork: <MPMediaLibraryArtwork: 0x289591590> with error; Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.mediaartworkd.xpc was invalidated: failed at lookup with error 159 - Sandbox restriction." UserInfo={NSDebugDescription=The connection to service named com.apple.mediaartworkd.xpc was invalidated: failed at lookup with error 159 - Sandbox restriction.}
2023-07-26 11:49:47.317262+0200 Plum[998:297199] [Artwork] Failed to create color analysis for artwork: file:///var/mobile/Media/iTunes_Control/iTunes/Artwork/Originals/4b/48d7b8d349d2de858413ae4561b6ba1b294dc7
2023-07-26 11:49:47.323099+0200 Plum[998:297013] [Plum] IIOImageWriteSession:121: cannot create: '/var/mobile/Media/iTunes_Control/iTunes/Artwork/Caches/320x320/4b/48d7b8d349d2de858413ae4561b6ba1b294dc7.sb-f9c7943d-6ciLNp'error = 1 (Operation not permitted)
My guess is that the most performance-heavy task here is performing the color analysis for each artwork but IMO the property backgroundColor should not be a stored property if that's the case. I am not planning to use it anywhere and if so it should be a computed async property so it doesn't block the caller.
I know I can move the call to a background thread and that fixes the issue of blocking main thread but still the loading times for each artwork are terribly slow and that impacts the UX.
SwiftUI's ArtworkImage loads the artworks much quicker and without the errors so there must be a better way to do it.
Hi,
In the iOS13 and macOS Catalina release notes it says:
Metal CIKernel instances now support arguments with arbitrarily structured data.
I've been trying to use this functionality in a CIKernel with mixed results. I'm particularly interested in passing data in the form of a dynamically sized array. It seems to work up to a certain size. Beyond the threshold excessive data is discarded and the kernel becomes unstable. I assume there is some kind of memory alignment issue going on, but I've tried various types in my array and always get a similar result.
I have not found any documentation or sample code regarding this. It would be great to know how this is intended to work and what the limitations are.
In the forums there are two similar unanswered questions about data arguments, so I'm sure there are a few out there with similar issues.
Thanks!
Michael
Our iOS/AppleTV video content playback app uses AVPlayer to play HLS video streams and supports both custom and system playback UIs. The Fairplay content key is retrieved using AVContentKeySession. AirPlay is supported too.
When the iPhone is connected to a TV through the lightning Apple Digital AV Adapter (A1438), the app is mirrored as expected.
Problem: when using an iPhone or iPad on iOS 18.1.1, FairPlay-protected HLS streams are not played and a CoreMediaErrorDomain -12035 error is received by the AVPlayerItem. Also, once the issue has occurred, the mirroring freezes (the TV indefinitely displays the app playback screen) although the app works fine on the iOS device.
The content key retrieval works as expected (I can see that 2 content key requests are made by the system by the way, probably one for the local playback and one for the adapter, as when AirPlaying) and the error is thrown after providing the AVContentKeyResponse.
Unfortunately, and as far as I know, there is not documentation on CoreMediaErrorDomain errors so I don't know what -12035 means.
The issue does not occur:
on an iPhone on iOS 17.7 (even with FairPlay-protected HLS streams)
when playing DRM-free video content (whatever the iOS version)
when using the USB-C AV Adapter (whatever the iOS version)
Also worth noting: the issue does not occur with other video playback apps such as Apple TV or Netflix although I don't have any details on the kind of streams these apps play and the way the FairPlay content key is retrieved (if any) so I don't know if it is relevant.
Hi, I'm working on an AUv3 project.
The app itself displays my icon.
However the Auv3 extension does not display any icon in any host app (AUM, Drambo, etc.0).
I thought that the extension would inherit the host app icon but that it does not appear to be the case.
I tried to add the icon as a 1024x1024 file to the extension target and the update my extension plist file withe a CFBundleIconFile key but no luck either.
It must surely be really easy. What am I missing?
Thanks in advance for your help!
Topic:
Media Technologies
SubTopic:
Audio
I have an app that edits photos in your library. When I call
try CIContext().writeHEIFRepresentation(of: editedImage, to: fileURL, format: .RGBA8, colorSpace: originalImage.colorSpace!)
The following is logged to the console:
writeImageAtIndex:1012: ⭕️ ERROR: 'App' is trying to save an opaque image (5712x4284) with 'AlphaLast'. This would unnecessarily increase the file size and will double (!!!) the required memory when decoding the image --> ignoring alpha.
What does that mean and how can I resolve it?
Xcode Version 16.0 (16A242d)
iOS 18.1 (22B82)
When i use AVPlayer to obtain the video frame CVPixelBufferRef of an HDR video, and use AVSampleBufferDisplayLayer to display it on the screen, after a period of time, the HDR video content and screen gradually darken, losing the HDR effect.
Steps to reproduce:
Create an AVPlayer to loop an HDR video, specify the video frame format as kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange
Create a timer to get the video frame CVPixelBufferRef at 30 frames per second
Use AVSampleBufferDisplayLayer to display CVPixelBufferRef on the screen
Don't operate the phone, wait for a period of time (such as 40 minutes), the HDR effect disappears and the screen darkens
Note:
You need to use an iPhone device, iOS 18.5 and below operating system
You need to ensure that the HDR video is played in a loop, that is, to ensure that the screen continues to display HDR content, wait for a period of time, depending on different devices, you need to wait for 20-40 minutes.
In the iPhone Photos app,the same problem will occur after playing HDR video in a loop for a long time
Expected Results:
When rendering HDR content for a long time, it is guaranteed that there is always an HDR effect, and the HDR content and screen will not be darkened.
Current Results:
After about 20-40 minutes, the HDR effect disappears and the screen darkens.
So I'm using AVAudioEngine. When playing audio I become the 'now playing' app using MPNowPlayingInfoCenter/MPRemoteCommandCenter APIs.
When configuring MPRemoteCommandCenter I add a play/pause command target via -addTargetWithHandler on the togglePlayPauseCommand property.
Now I also have a play/pause button in my app's UI. When I pause playback from my app's UI (which means I'm the active app, I'm in the foreground), what I do is this:
-I pause the AVAudioPlayerNode I'm using with AVAudioEngine.
I do not, stop, reset, etc. the AVAudioEngine. I only pause the player node. My thought process here is that the user just pressed pause and it is very likely that he will hit 'play' to resume playback in the near future because
My app is in the foreground and the user just hit the pause button.
Now if my app moves to the background and if I receive a memory warning I presume it'd make sense to tear down the engine or pause it. Perhaps I'm wrong about this?
So when I initially hit the play button from my app's UI I also activate my AVAudioSession. I do this in high priority NSOperation since the documentation warns that "we recommend that applications not activate their session from a thread where a long blocking operation will be problematic."
So now I'm playing and I hit pause from my app's UI. Then I quickly bring up the "Now Playing" center and I see I'm the "Now Playing" app but the play-pause button is showing the pause icon instead of the play icon but I'm in the pause state. I do set MPNowPlayingInfoCenter's playbackState to MPNowPlayingPlaybackStatePaused when I pause. Not surprisingly this doesn't work. The documentation states this is for macOS only.
So the only way to get MPRemoteCommandCenter to show the "play" image for the play-pause button is to deactivate my AVAudioSession when I pause playback? Since I change the active state of my audio session in a NSOperation because documentation recommends "we recommend that applications not activate their session from a thread where a long blocking operation will be problematic." the play-pause toggle in the remote command center won't immediately update since I'm doing it on another thread.
IMO it feels kind of inappropriate for a play-pause button to wait on a NSOperation activating the audio session before updating its UI when I already know my play/paused state, it should update right away like the button in my app does. Wouldn't it be nicer to just use MPNowPlayingInfoCenter's playbackState property on iOS too? If I'm no the longer the now playing app/active audio session it doesn't matter since I'm not in the now playing UI, just ignore it?
Also is it recommended that I deactivate my audio session explicitly every time the user pauses audio in my app (when I'm in the foreground)?
Also when I do deactivate the audio session I get an error: AVAudioSessionErrorCodeIsBusy (but the button in the now playing center updates to the proper image). I do this :
-(void)pause
{
[self.playerNode pause];
[self runOperationToDeactivateAudioSession];
// This does nothing on iOS:
MPNowPlayingInfoCenter *nowPlayingCenter = [MPNowPlayingInfoCenter defaultCenter];
nowPlayingCenter.playbackState = MPNowPlayingPlaybackStatePaused;
}
So in -runOperationToDeactivateAudioSession I get the AVAudioSessionErrorCodeIsBusy. According to the documentation
Starting in iOS 8, if the session has running I/Os at the time that deactivation is requested, the session will be deactivated, but the method will return NO and populate the NSError with the code property set to AVAudioSessionErrorCodeIsBusy to indicate the misuse of the API.
So pausing the player node when pausing isn't enough to meet the deactivation criteria. I guess I have to pause or stop the audio engine. I could probably wait until I receive a scene went to background notification or something before deactivating my audio session (which is async, so the button may not update to the correct image in time). This seems like a lot of code to have to write to get a play-pause toggle to update, especially in iPad-multi window scene environment.
What's the recommended approach?
Should I pause the AudioEngine instead of the player node always?
Should I always explicitly deactivate my audio session when the user pauses playback from my app's UI even if I'm in the foreground?
I personally like the idea of just being able to set
[MPNowPlayingInfoCenter defaultCenter].playbackState = MPNowPlayingPlaybackStatePaused;
But maybe that's because that would just make things easier on me. This does feels overcomplicated though. If anyone can share some tips on how I should handle this, I'd appreciate it.
Does anyone have a template of an Apple Projected Media Profile Format Description or a File of a Stereo wideFOV video?
Use case I have 2 compatible cameras that I stereo sync and I want to move the projection information from the compatible video to the Spatial video that combines them.
Every version I can come up with crashes the AVP and when viewing as Spatial in Tahoe I just get a black screen.
Hi,
I'm working on an audio mixing app, that comes with bundled audio units that provide some of the app's core functionality.
For the next release of that app, we are planning to make two changes:
make the app sandboxed
package the bundled audio units as .appex bundles instead as .component bundles, so we don't need to take care of the installation at the correct spot in the file system
When trying this new approach, we run into problems where [[AVAudioUnitEffect alloc] initWithAudioComponentDescription:] crashes when trying to load our audio unit with the exception:
AVAEInternal.h:109 [AUInterface.mm:468:AUInterfaceBaseV3: (AudioComponentInstanceNew(comp, &_auv2)): error -10863
Our audio unit has the `sandboxSafe flag enabled, and loads fine when the host app is not sandboxed, so I'm guessing I got the bundle id/code signing requirements for the .appex correct.
It seems, that my .appex isn't even loaded, and the system rejects it because of its metadata. Maybe there something wrong the Info.plist generated by Juice?
"BuildMachineOSBuild" => "23H222"
"CFBundleDisplayName" => "elgato_sample_recorder"
"CFBundleExecutable" => "ElgatoSampleRecorder"
"CFBundleIdentifier" => "com.iwascoding.EffectLoader.samplerecorderAUv3"
"CFBundleName" => "elgato_sample_recorder"
"CFBundlePackageType" => "XPC!"
"CFBundleShortVersionString" => "1.0.0.0"
"CFBundleSignature" => "????"
"CFBundleSupportedPlatforms" => [
0 => "MacOSX"
]
"CFBundleVersion" => "1.0.0.0"
"DTCompiler" => "com.apple.compilers.llvm.clang.1_0"
"DTPlatformBuild" => "24C94"
"DTPlatformName" => "macosx"
"DTPlatformVersion" => "15.2"
"DTSDKBuild" => "24C94"
"DTSDKName" => "macosx15.2"
"DTXcode" => "1620"
"DTXcodeBuild" => "16C5032a"
"LSMinimumSystemVersion" => "10.13"
"NSExtension" => {
"NSExtensionAttributes" => {
"AudioComponents" => [
0 => {
"description" => "Elgato Sample Recorder"
"factoryFunction" => "elgato_sample_recorderAUFactoryAUv3"
"manufacturer" => "Manu"
"name" => "Elgato: Elgato Sample Recorder"
"sandboxSafe" => 1
"subtype" => "Znyk"
"tags" => [
0 => "Effects"
]
"type" => "aufx"
"version" => 65536
}
]
}
"NSExtensionPointIdentifier" => "com.apple.AudioUnit-UI"
"NSExtensionPrincipalClass" => "elgato_sample_recorderAUFactoryAUv3"
}
"NSHighResolutionCapable" => 1
}
Any ideas what I am missing?
Since upgrading to tvOS 18, the above function isn't working for me in converting a stream with these formats. It does work in decoding AAC, however.
https://developer.apple.com/documentation/audiotoolbox/1503098-audioconverterfillcomplexbuffer?language=objc
I pass a valid ioOutputDataPacketSize in, but it always comes out as zero.
Has anyone else observed this too?
I wonder if this is related to the issue being discussed widely about 5.1 sound being broken for many people after upgrading to tvOS 18?
https://discussions.apple.com/thread/255769102?login=true&sortBy=rank
EDIT: further information; the callback gets called once, asking for 1 packet (which is ok). I give it one packet and return noErr. However, after this, the callback is never invoked again. Must be a bug?
EDIT2: the same code continues to work correctly on macOS in decoding the same audio stream.
This is an issue with the Insta360 Flow Pro 2.
My iOS app uses DockKit to control the gimbal; in particular, my app disables tracking and sends angular velocity commands to control the gimbal's orientation. I only try to modify the yaw (rotation around the vertical axis); never the pitch or yaw. Note that I don't send the gimbal to a particular orientation directly; I modify the velocity.
Everything works great for a long period of time: typically for a continuous run of 4-6 hours; in the most recent case, I managed about 36 hours of continous operation before the following problem occurred.
I came back to check on the system, and because no visual activity had occurred in the camera's field of view for a while, the phone had commanded the gimbal to rotate back to a yaw angle of 0 degrees.
So the phone in the gimbal should have been looking straight ahead (i.e. the 0 degree yaw position), but it was definitely looking off at an angle. I've seen this twice now. The first time, when it should have been looking straight ahead, it was in fact looking 60 degrees off center. This time (caught on video, see below), it was off by 22 degrees from center.
Here's the weird part: the gimbal reports this way off center positioning as zero degrees (well close enough to zero, like 0.2 or something that's fine). But, mechanically, the gimbal still knows where zero degrees is: if we double click on the trigger of the Flow Pro 2, which is supposed to reset the gimbal to 0 degrees yaw and pitch, the gimbal responds correctly and reorients to a 0 degree position. However, the yaw values it reports are not zero, but as shown in my video, 22 degrees off axis or so.
Power cycling the gimbal and restarting immediately fixes the problem. Also, I switched from my app to the Insta360 app, which caused the phone to flip from landscape to portrait, then when I returned to my app and switched back to landscape, the gimbal now started reporting correct yaw angles.
Is there a possibility this is a bug in the DockKit framework? Has anyone seen this? I have a case open with Insta360, but although it's clearly a software issue, it's not clear if it's in Insta360's code or the DockKit layer. Any ideas for how I can get out of this mode? My concern is that the phone is in a tripod about 10' off the floor, and not very accessible. Also, if all goes well, we may have about 50 of these systems running, and having to fix them one by one after a few hours is not good.
For a demonstration of this bug, see the following video:
https://octoparry.com/offset.MOV
Any help greatly appreciated.
Hi all,
we are in the business of scanning documents and barcodes with the camera system of mobile devices. Since there is a wide variety of use cases, from scanning tiniest barcodes and small business cards to scanning barcodes or large documents from far distances we preferably rely on the triple camera devices, if available, with automatic constituent device switching.
This approach used to be working perfectly fine. Depending on the zoom level (we prefer to use an initial zoom value of 2.0) and the focusing distance the iPhone Pro models switched through the different camera systems at light speed: from ultra-wide to wide, tele and back. No issues at all.
Unfortunately the new iPhone 16 Pro models behave very different when it comes to constituent device switching based on focus distance. The switching is slow and sometimes it does not happen at all when the focusing distance changes. Especially when aiming for a at a distant object for a longer time and then aiming at a very close object that is maybe 2" away. The iPhone 15 Pro here always switches immediately to the ultra-wide camera, while the iPhone 16 Pro takes at least 2-3 seconds, in rare cases up to 10 seconds and sometimes forever to switch to the ultra-wide camera.
Of course we assumed that our code is responsible for these issues. So we experimented with restricting the devices and so on. Then we stripped more and more configuration code but nothing we tried improved the situation.
So we ended up writing a minimal example app that demonstrates the problem. You can find the code below. Execute it on various iPhones and aim at far distance (> 10 feet) and then quickly to very close distance (<5 inches).
Here is a list of devices and our test results:
iPhone 15 Pro, iOS 17.6: very fast and reliable switching
iPhone 15 Pro, iOS 18.1: very fast and reliable switching
iPhone 13 Pro Max, iOS 15.3: very fast and reliable switching
iPhone 16 (dual-wide camera), iOS 18.1: very fast and reliable switching
iPhone 16 Pro, iOS 18.1: slow switching, unreliable
iPhone 16 Pro Max, iOS 18.1: slow switching, unreliable
Questions:
Does anyone else have seen this issue? And possibly found a workaround?
Is this behaviour intended on iPhone 16 Pro models? Can we somehow improve the switching speed?
Further the iPhone 16 Pro models also show a jumping preview in the preview layer when they switch the constituent active device. Not dramatic, but compared to the other phones it looks like a glitch.
Thank you very much!
Kind regards,
Sebastian
import UIKit
import AVFoundation
class ViewController: UIViewController {
var captureSession : AVCaptureSession!
var captureDevice : AVCaptureDevice!
var captureInput : AVCaptureInput!
var previewLayer : AVCaptureVideoPreviewLayer!
var activePrimaryConstituentToken: NSKeyValueObservation?
var zoomToken: NSKeyValueObservation?
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
checkPermissions()
setupAndStartCaptureSession()
}
func checkPermissions() {
let cameraAuthStatus = AVCaptureDevice.authorizationStatus(for: AVMediaType.video)
switch cameraAuthStatus {
case .authorized:
return
case .denied:
abort()
case .notDetermined:
AVCaptureDevice.requestAccess(for: AVMediaType.video, completionHandler:
{ (authorized) in
if(!authorized){
abort()
}
})
case .restricted:
abort()
@unknown default:
fatalError()
}
}
func setupAndStartCaptureSession() {
DispatchQueue.global(qos: .userInitiated).async{
self.captureSession = AVCaptureSession()
self.captureSession.beginConfiguration()
if self.captureSession.canSetSessionPreset(.photo) {
self.captureSession.sessionPreset = .photo
}
self.captureSession.automaticallyConfiguresCaptureDeviceForWideColor = true
self.setupInputs()
DispatchQueue.main.async {
self.setupPreviewLayer()
}
self.captureSession.commitConfiguration()
self.captureSession.startRunning()
self.activePrimaryConstituentToken = self.captureDevice.observe(\.activePrimaryConstituent, options: [.new], changeHandler: { (device, change) in
let type = device.activePrimaryConstituent!.deviceType.rawValue
print("Device type: \(type)")
})
self.zoomToken = self.captureDevice.observe(\.videoZoomFactor, options: [.new], changeHandler: { (device, change) in
let zoom = device.videoZoomFactor
print("Zoom: \(zoom)")
})
let switchZoomFactor = 2.0
DispatchQueue.main.async {
self.setZoom(CGFloat(switchZoomFactor), animated: false)
}
}
}
func setupInputs() {
if let device = AVCaptureDevice.default(.builtInTripleCamera, for: .video, position: .back) {
captureDevice = device
} else {
fatalError("no back camera")
}
guard let input = try? AVCaptureDeviceInput(device: captureDevice) else {
fatalError("could not create input device from back camera")
}
if !captureSession.canAddInput(input) {
fatalError("could not add back camera input to capture session")
}
captureInput = input
captureSession.addInput(input)
}
func setupPreviewLayer() {
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
view.layer.addSublayer(previewLayer)
previewLayer.frame = self.view.layer.frame
}
func setZoom(_ value: CGFloat, animated: Bool) {
guard let device = captureDevice else { return }
let maxZoom: CGFloat = captureDevice.maxAvailableVideoZoomFactor
let minZoom: CGFloat = captureDevice.minAvailableVideoZoomFactor
let zoomValue = max(min(value, maxZoom), minZoom)
let deltaZoom = Float(abs(zoomValue - device.videoZoomFactor))
do {
try device.lockForConfiguration()
if animated {
device.ramp(toVideoZoomFactor: zoomValue, withRate: max(deltaZoom * 50.0, 50.0))
} else {
device.videoZoomFactor = zoomValue
}
device.unlockForConfiguration()
} catch {
return
}
}
}
I've been generating new Audio Unit Extension apps with Xcode 16 (and newer), and although they generally work initially, it is easy (although I'm not sure how to do it reliably) to cause the app to no longer be able to instantiate the audiounit. Generally the call to AVAudioUnit.findComponent fails and SimplePlayEngine hits the fatalError("Failed to find component with type...")
In the most recent project, merely adding files to the extension (without making any use of them) caused it to go off the rails.
If I "Archive" the app+plugin, there is no audio unit extension in the bundle.
If I switch to the audiounit extension and build it it's fine. If I look at the build folder in Library/Developer/Xcode/project_folder the extension_name.appex is there.
Any ideas? If I can coax an unmodified audio unit extension project to exhibit this behavior I'll attach it here. Right now what I have has code I don't want to share.