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.

I want the audio session to always use the built-in microphone. However, when using the setPreferredInput() method like in this example private func enableBuiltInMic() { // Get the shared audio session. let session = AVAudioSession.sharedInstance() // Find the built-in microphone input. guard let availableInputs = session.availableInputs, let builtInMicInput = availableInputs.first(where: { $0.portType == .builtInMic }) else { print("The device must have a built-in microphone.") return } // Make the built-in microphone input the preferred input. do { try session.setPreferredInput(builtInMicInput) } catch { print("Unable to set the built-in mic as the preferred input.") } } and calling that function once in the initializer, the audio session still switches to the external microphone once one is plugged in. The session's preferredInput is nil again at that point, even if the built-in microphone is still listed in availableInputs. So, why is the preferredInput suddenly reset? when would be the appropriate time to set the preferredInput again? Observing the session’s availableInputs did not work and setting the preferredInput again in the routeChangeNotification handler seems a bad choice as it’s already a bit too late then.

Dear Sirs, I'd like to add an icon to my audio driver based on AudioDriverKit. This icon should show up left of my audio device in the audio devices dialog. For an Audio Server Plugin I managed to do this using the property kAudioDevicePropertyIcon and CFBundleCopyResourceURL(...) but how would you do this with AudioDriverKit? Should I use IOUserAudioCustomProperty or IOUserAudioControl and how would I refer to the Bundle? Is there an example available somewhere? Thanks and best regards, Johannes

Recently I've been trying to play some AV1-encoded streams on my iPhone 15 Pro Max. First, I check for hardware support: VTIsHardwareDecodeSupported(kCMVideoCodecType_AV1); // YES Then I need to create a CMFormatDescription in order to pass it into a VTDecompressionSession. I've tried the following: { mediaType:'vide' mediaSubType:'av01' mediaSpecific: { codecType: 'av01' dimensions: 394 x 852 } extensions: {{ CVFieldCount = 1; CVImageBufferChromaLocationBottomField = Left; CVImageBufferChromaLocationTopField = Left; CVPixelAspectRatio = { HorizontalSpacing = 1; VerticalSpacing = 1; }; FullRangeVideo = 0; }} } but VTDecompressionSessionCreate gives me error -8971 (codecExtensionNotFoundErr, I assume). So it has something to do with the extensions dictionary? I can't find anywhere which set of extensions is necessary for it to work 😿. VideoToolbox has convenient functions for creating descriptions of AVC and HEVC streams (CMVideoFormatDescriptionCreateFromH264ParameterSets and CMVideoFormatDescriptionCreateFromHEVCParameterSets), but not for AV1. As of today I am using XCode 15.0 with iOS 17.0.0 SDK.

I'm developing iPad app that will be mostly dedicated for certain external camera for visually impaired people. The linux UVC api (e.g. using guvcview) allows to enable automatic exposure for the camera. IOs api "isExposureModeSupported" unfortunately returns false for any of the exposure modes. Is it a bug? Or perhaps AVFoundation doesn't support UVC exposure yet?

Hi, I am creating an app that can include videos or images in it's data. While @Attribute(.externalStorage) helps with images, with AVAssets I actually would like access to the URL behind that data. (as it would be stupid to load and then save the data again just to have a URL) One key component is to keep all of this clean enough so that I can use (private) CloudKit syncing with the resulting model. All the best Christoph

I'm using iCloud Music Library. I’m using macOS 14.1 (23B74) and iOS 17.1. i’m using MusicKit to find songs that do not have artwork. On iOS, Song.artwork will be nil for items I know do not have artwork. On macOS, Song.artwork is not nil. However when the songs are shown in Music.app, they do not have Artwork. Is this expected? Alternately, is there a more correct way to determine that a Song has no Artwork? I have also filed FB13315721. Thank you for any tips!

So I've spent the last five years optimizing my video AI system so that it runs with less than 5% CPU while processing a 30fps video feed on a Macbook Pro M2, and everything is great, until Sonoma comes out, and I find myself consuming 40% CPU for the exact same workload. So I fire up Instruments, and the "heaviest stack trace" (see screenshot) turns out to be Espresso doing some completely unasked-for and absolutely useless processing on my video frames. I turn off Reactions, but nothing helps - the CPU consumptions stays at 40%. "Reactions" is nothing but a useless toy to please some WWDC keynote fanboys, I don't want it anywhere near my app or my users, and I especially do not want to take the blame for it pissing away the user's CPU cycles and battery. Now, how do I make it go away, for ever? Best regards Jacob

Hey there, I'm trying to display all user's albums using the MediaPlayer library. I'm getting many albums returning nil, but I know artwork exists because they show up in the default Music app. There doesn't seem to be much rhyme or reason for what shows up and what doesn't. All downloaded albums display artwork, but some cloud album artwork displays as well. Here's the code I'm using to debug this. let query = MPMediaQuery.albums() if let albumCollections = query.collections { albums = albumCollections } for album in albums { let artwork = album.representativeItem?.artwork print(artwork, artwork?.image(at: CGSize(width: 100, height: 100))) } Any help would be greatly appreciated. Thanks!

Hello, Starting in iOS 17, our application started having some issue publishing to our video session. More specifically the video capture seems to be broken in some, but not all sessions. What's troubling is that we're seeing that it fails consistently every 4 sessions. It also fails silently, without reporting any problems to the app. We only notice that there are no frames being rendered or sent to the remote devices. Here's what shows-up in the console: <<<< FigCaptureSourceRemote >>>> Fig assert: "! storage->connectionDied" at bail (FigCaptureSourceRemote.m:235) - (err=0) <<<< FigCaptureSourceRemote >>>> Fig assert: "err == 0 " at bail (FigCaptureSourceRemote.m:253) - (err=-16453) Anyone seeing this? Any idea what could be the cause? Our sessions work perfectly on iOS16 and below. Thanks

I have a PCM audio buffer (AVAudioPCMFormatInt16). When I try to play it using AVPlayerNode / AVAudioEngine an exception is thrown: "[[busArray objectAtIndexedSubscript:(NSUInteger)element] setFormat:format error:&nsErr]: returned false, error Error Domain=NSOSStatusErrorDomain Code=-10868 (related thread https://forums.developer.apple.com/forums/thread/700497?answerId=780530022#780530022) If I convert the buffer to AVAudioPCMFormatFloat32 playback works. My questions are: Does AVAudioEngine / AVPlayerNode require AVAudioPCMBuffer to be in the Float32 format? Is there a way I can configure it to accept another format instead for my application? If 1 is YES is this documented anywhere? If 1 is YES is this required format subject to change at any point? Thanks! I was looking to watch the "AVAudioEngine in Practice" session video from WWDC 2014 but I can't find it anywhere (https://forums.developer.apple.com/forums/thread/747008).

I often find when doing basic actions in MusicKit it is incredibly slow compared to Apple's Music App. I've tried different versions, devices, networks, Apple's sample code, it all throughout the last several years, and it is all the same. Does anyone else have this issue?

Hi, is there a way to display the animated cover art in an app? Not every album has a cover art but for the ones that have one I would like to display them instead of the artwork. Thank you :)

I'm using AVAudioEngine to play AVAudioPCMBuffers. I'd like to synchronize some events with the playback. For example if the audio's frame position is >= some point && less than some point trigger some code. So I'm looking at - (void)installTapOnBus:(AVAudioNodeBus)bus bufferSize:(AVAudioFrameCount)bufferSize format:(AVAudioFormat * __nullable)format block:(AVAudioNodeTapBlock)tapBlock; Now I have frame positions calculated (predetermined before audio is scheduled I already made all necessary computations) . So I just need to fire code at certain points during playback: [playerNode installTapOnBus:bus bufferSize:bufferSize format:format block:^(AVAudioPCMBuffer * _Nonnull buffer, AVAudioTime * _Nonnull when) { //Inspect current audio here and fire... }]; [playerNode scheduleBuffer:fullbuffer atTime:startTime options:0 completionCallbackType:AVAudioPlayerNodeCompletionDataPlayedBack completionHandler:^(AVAudioPlayerNodeCompletionCallbackType callbackType) { // some code is here, not important to this question. }]; The problem I'm having is figuring out at what point in full buffer I'm at within the tap block. The tap block passes chunks (not the full audio buffer). I tried using the when parameter of the block to calculate the frame position relative to the entire audio but have be unsuccessful so far. I'm assuming the when parameter is relative to the buffer passed in the tap block (not my entire audio buffer I scheduled). Not installing a tap and just using a timer before scheduling my fullBuffer has given me good results but I'd rather avoid using a timer if possible and use sample time.

In SwiftUI there is a built-in component for displaying album artworks called Artwork but there is no equivalent for UIKit. My current approach is to use the .url() method to read image's URL and download the image or read it from the disk but the performance is much worse than it was previously with MPMediaItem's artworkImage method. let artworkQueue = DispatchQueue( label: "MusicKit-ArtworkQueue", qos: .default, attributes: .concurrent ) let artworkSemaphore = DispatchSemaphore(value: 5) extension Song { func artworkImage(for size: CGSize, completion: @escaping (UIImage?) -> Void) { artworkQueue.async { artworkSemaphore.wait() defer { artworkSemaphore.signal() } let imageURL = artwork?.url( width: Int(size.width), height: Int(size.height) ) // I hate doing this as it might very well break in the future guard let imageURL, imageURL.scheme == "musicKit" else { return completion(nil) } guard let imageData = try? Data(contentsOf: imageURL), let image = UIImage(data: imageData) else { return completion(nil) } completion(image) } } } I really dislike this approach because it feels hacky but somewhat works. You might ask what's the semaphore for? Well, without it I could notice that MusicKit was choking and after reading too many artworks at once. Can someone from Apple please provide us with an example on how to use MusicKit with UIKit properly? Ideally (IMO) we would have a method defined on Song and other MusicKit structures that returns the image for us, just like MPMediaItem had the .artwork() method. It would make our lives so much easier.

Hi! I have a music app using AVAudioEngine. Right now, I have set it up to play multi channel tracks and show "Multichannel" in the volume controls. However, I am unable to figure out how to get it to use Dolby Atmos. Is there something that needs to be enabled? Is it even possible for AVAudioEngine? I saw some apps that are able of playing with Dolby Atmos, but they do not have EQ feature, so I'm guessing that they are not using AVAudioEngine.

I am using MusicKit ApplicationMusicPlayer to play music in my app. Everything works fine as long as I'm not playing large playlists that contain hundreds of songs. When I to play collection of songs that is larger than around 300 I'm always getting the error message saying: "Prepare to play failed" UserInfo={NSDebugDescription=Prepare to play failed, NSUnderlyingError=0x121d42dc0 {Error Domain=MPMusicPlayerControllerErrorDomain Code=9 "Remote call timed out" UserInfo={NSDebugDescription=Remote call timed out}}})) It doesn't matter if songs are downloaded to the device or not. I am aware that there is another initializer for player's queue that accepts Playlist instances but in my app users can choose to sort playlist tracks in different order than the default and that makes using that initializer not feasible for me. I tried everything I could think of, I tried to fall back on MPMusicPlayerController and pass array of MPMusicPlayerPlayParameters to it but the result was the same. typealias QueueEntry = ApplicationMusicPlayer.Queue.Entry let player = ApplicationMusicPlayer.shared let entries: [QueueEntry] = tracks .compactMap { guard let song = $0 as? Song else { return nil } return QueueEntry(song) } Task(priority: .high) { [player] in do { player.queue = .init(entries, startingAt: nil) try await player.play() // prepareToPlay failed } catch { print(error) } }

Hi, just generated a HDR10 MVHEVC file, mediainfo is below: Color range : Limited Color primaries : BT.2020 Transfer characteristics : PQ Matrix coefficients : BT.2020 non-constant Codec configuration box : hvcC+lhvC then generate the segment files with below command: mediafilesegmenter --iso-fragmented -t 4 -f av_1 av_new_1.mov then upload the segment files and prog_index.m3u8 to web server. just find that can not play the HLS stream on Safari... the url is http://ip/vod/prog_index.m3u8 just checked that if i remove the tag Transfer characteristics : PQ when generating the MVHEVC file. above same mediafilesegmenter command and upload the files to web server. the new version of HLS stream is can play on Safari... Is there any way to play HLS PQ video on Safari. thanks.

Hello, I have an iOS app that is recording audio that is working fine on iPads/iPhones. It asks for microphone permission and after that recording works. I installed the same app on my M3 MacBook via TestFlight since iPad apps are supposed to work without a change that way. The app starts fine and everything, but it never asks for Microphone permission, so I can't record. Do I need to do something to make this happen (this is not macCatalyst, its running the arm64 iPhone binary on macOS) thanks

Since iOS 12 it has become difficult to detect the end of playback using the system music player. In earlier iOS versions, the now playing item would be set nil and you would receive a notification that the player stopped. In iOS 12 and later, nowPlayingItem still contains the current song and the only notification you get is MPMusicPlayerControllerPlaybackStateDidChangeNotification with the playbackState set to MPMusicPlaybackStatePaused. Pressing pause in my car (or any remote access) generates the same conditions making it difficult to correctly detect the difference. It would be nice if they added a notification that playback was done (similar to the other players). Any suggestions?