Explore the integration of media technologies within your app. Discuss working with audio, video, camera, and other media functionalities.

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How to disable/hide Audio Controls on lock screen from WkWebView
Hi, I am trying to remove the audio controls for my app on the lock screen. Since I use WKWebView, there are 3 audio tags in my html and I play and pause em via JS. However, if I do not play any sound since app launch, there are no audio controls on the lock screen. But if I play one of those 3 files (they are even less then 3 Sec sound effects e.g. for buttons) the audio controls appears on lock screen. Note even when the sounds on pause() or not playing they were listed on the lock screen. What I have tried so far without success MPNowPlayingInfoCenter.default().nowPlayingInfo = [:] and ``try audioSession.setCategory(.playback, mode: .default, options: []) try audioSession.setActive(false, options: .notifyOthersOnDeactivation)`` and UIApplication.shared.endReceivingRemoteControlEvents() Another problem is that the app scales with iOS system settings "display zoom". Is there a way to deny it? It is latest Xcode verion 16.3 and iOS 18. I have no background mode in my Capabilities. Nothing worked so far. Has anyone an idea? Greetings
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135
May ’25
CVPixelBufferCreate EXC_BAD_ACCESS
I am doing something similar to this post Within an AVCaptureDataOutputSynchronizerDelegate method, I create a pixelBuffer using CVPixelBufferCreate with the following attributes: kCVPixelBufferIOSurfacePropertiesKey as String: true, kCVPixelBufferIOSurfaceOpenGLESTextureCompatibilityKey as String: true When I copy the data from the vImagePixelBuffer "rotatedImageBuffer", I get the following error: Thread 10: EXC_BAD_ACCESS (code=1, address=0x14caa8000) I get the same error with memcpy and data.copyBytes (not running them at the same time obviously). If I use CVPixelBufferCreateWithBytes, I do not get this error. However, CVPixelBufferCreateWithBytes does not let you include attributes (see linked post above). I am using vImage because I need the original CVPixelBuffer from the camera output and a rotated version with a different color scheme. // Copy to pixel buffer let attributes: NSDictionary = [ true : kCVPixelBufferIOSurfacePropertiesKey, true : kCVPixelBufferIOSurfaceOpenGLESTextureCompatibilityKey, ] var colorBuffer: CVPixelBuffer? let status = CVPixelBufferCreate(kCFAllocatorDefault, Int(rotatedImageBuffer.width), Int(rotatedImageBuffer.height), kCVPixelFormatType_32BGRA, attributes, &colorBuffer) //let status = CVPixelBufferCreateWithBytes(kCFAllocatorDefault, Int(rotatedImageBuffer.width), Int(rotatedImageBuffer.height), kCVPixelFormatType_32BGRA, rotatedImageBuffer.data, rotatedImageBuffer.rowBytes, nil, nil, attributes as CFDictionary, &colorBuffer) // does NOT produce error, but also does not have attributes guard status == kCVReturnSuccess, let colorBuffer = colorBuffer else { print("Failed to create buffer") return } let lockFlags = CVPixelBufferLockFlags(rawValue: 0) guard kCVReturnSuccess == CVPixelBufferLockBaseAddress(colorBuffer, lockFlags) else { print("Failed to lock base address") return } let colorBufferMemory = CVPixelBufferGetBaseAddress(colorBuffer)! let data = Data(bytes: rotatedImageBuffer.data, count: rotatedImageBuffer.rowBytes * Int(rotatedImageBuffer.height)) data.copyBytes(to: colorBufferMemory.assumingMemoryBound(to: UInt8.self), count: data.count) // Fails here //memcpy(colorBufferMemory, rotatedImageBuffer.data, rotatedImageBuffer.rowBytes * Int(rotatedImageBuffer.height)) // Also produces the same error CVPixelBufferUnlockBaseAddress(colorBuffer, lockFlags)
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310
Apr ’25
AVB Support for the AVnu MILAN Conventions
The AVB AVnu MILAN Convention has a groweing Population. Many big companies (Cisco, Meyer Sound, d&b Audio, l‘acoustics, Presonus, digico etc.) implements the AVB AVnu Milan Standards. Is there a plan on the Apple side to also implement AVnu Milan on top of the AVB Protocol? The advantage for Apple Sound would be a great Integration in the professionell Audio market and a more stable intergration on top of the AVB protocol. The atdecc work, but Not that stable.
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178
Oct ’25
Apple watch for child
Hi, my daughter was given an Apple Watch due to her grandfather's passing. It is not GPS/cellular, and we cannot connect it to her Apple ID because of this. It doesn't seem right to leave her logged in to his Apple ID, but we are currently out of options. Is there a workaround to this? When I try to set her up from my phone, it tells me that the watch must have GPS/cellular to set it up. Why? Am I missing something?
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170
Jun ’25
Crackling/Popping sound when using AVAudioUnitTimePitch
I have a simple AVAudioEngine graph as follows: AVAudioPlayerNode -> AVAudioUnitEQ -> AVAudioUnitTimePitch -> AVAudioUnitReverb -> Main mixer node of AVAudioEngine. I noticed that whenever I have AVAudioUnitTimePitch or AVAudioUnitVarispeed in the graph, I noticed a very distinct crackling/popping sound in my Airpods Pro 2 when starting up the engine and playing the AVAudioPlayerNode and unable to find the reason why this is happening. When I remove the node, the crackling completely goes away. How do I fix this problem since i need the user to be able to control the pitch and rate of the audio during playback. import AVKit @Observable @MainActor class AudioEngineManager { nonisolated private let engine = AVAudioEngine() private let playerNode = AVAudioPlayerNode() private let reverb = AVAudioUnitReverb() private let pitch = AVAudioUnitTimePitch() private let eq = AVAudioUnitEQ(numberOfBands: 10) private var audioFile: AVAudioFile? private var fadePlayPauseTask: Task<Void, Error>? private var playPauseCurrentFadeTime: Double = 0 init() { setupAudioEngine() } private func setupAudioEngine() { guard let url = Bundle.main.url(forResource: "Song name goes here", withExtension: "mp3") else { print("Audio file not found") return } do { audioFile = try AVAudioFile(forReading: url) } catch { print("Failed to load audio file: \(error)") return } reverb.loadFactoryPreset(.mediumHall) reverb.wetDryMix = 50 pitch.pitch = 0 // Increase pitch by 500 cents (5 semitones) engine.attach(playerNode) engine.attach(pitch) engine.attach(reverb) engine.attach(eq) // Connect: player -> pitch -> reverb -> output engine.connect(playerNode, to: eq, format: audioFile?.processingFormat) engine.connect(eq, to: pitch, format: audioFile?.processingFormat) engine.connect(pitch, to: reverb, format: audioFile?.processingFormat) engine.connect(reverb, to: engine.mainMixerNode, format: audioFile?.processingFormat) } func prepare() { guard let audioFile else { return } playerNode.scheduleFile(audioFile, at: nil) } func play() { DispatchQueue.global().async { [weak self] in guard let self else { return } engine.prepare() try? engine.start() DispatchQueue.main.async { [weak self] in guard let self else { return } playerNode.play() fadePlayPauseTask?.cancel() playPauseCurrentFadeTime = 0 fadePlayPauseTask = Task { [weak self] in guard let self else { return } while true { let volume = updateVolume(for: playPauseCurrentFadeTime / 0.1, rising: true) // Ramp up volume until 1 is reached if volume >= 1 { break } engine.mainMixerNode.outputVolume = volume try await Task.sleep(for: .milliseconds(10)) playPauseCurrentFadeTime += 0.01 } engine.mainMixerNode.outputVolume = 1 } } } } func pause() { fadePlayPauseTask?.cancel() playPauseCurrentFadeTime = 0 fadePlayPauseTask = Task { [weak self] in guard let self else { return } while true { let volume = updateVolume(for: playPauseCurrentFadeTime / 0.1, rising: false) // Ramp down volume until 0 is reached if volume <= 0 { break } engine.mainMixerNode.outputVolume = volume try await Task.sleep(for: .milliseconds(10)) playPauseCurrentFadeTime += 0.01 } engine.mainMixerNode.outputVolume = 0 playerNode.pause() // Shut down engine once ramp down completes DispatchQueue.global().async { [weak self] in guard let self else { return } engine.pause() } } } private func updateVolume(for x: Double, rising: Bool) -> Float { if rising { // Fade in return Float(pow(x, 2) * (3.0 - 2.0 * (x))) } else { // Fade out return Float(1 - (pow(x, 2) * (3.0 - 2.0 * (x)))) } } func setPitch(_ value: Float) { pitch.pitch = value } func setReverbMix(_ value: Float) { reverb.wetDryMix = value } } struct ContentView: View { @State private var audioManager = AudioEngineManager() @State private var pitch: Float = 0 @State private var reverb: Float = 0 var body: some View { VStack(spacing: 20) { Text("🎵 Audio Player with Reverb & Pitch") .font(.title2) HStack { Button("Prepare") { audioManager.prepare() } Button("Play") { audioManager.play() } .padding() .background(Color.green) .foregroundColor(.white) .cornerRadius(10) Button("Pause") { audioManager.pause() } .padding() .background(Color.red) .foregroundColor(.white) .cornerRadius(10) } VStack { Text("Pitch: \(Int(pitch)) cents") Slider(value: $pitch, in: -2400...2400, step: 100) { _ in audioManager.setPitch(pitch) } } VStack { Text("Reverb Mix: \(Int(reverb))%") Slider(value: $reverb, in: 0...100, step: 1) { _ in audioManager.setReverbMix(reverb) } } } .padding() } }
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282
Apr ’25
WorldCaptureKit
Does the library exists in xCode 16.4? "import WorldCaptureKit" gives error "No such module 'WorldCaptureKit'". And I do not find any information about the library in the apple documentation. But AI keeps suggesting me to use the library
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Jun ’25
Playback Issues for DRM content when sending CMCD
Since iOS and tvOS 18, CMCD can now be automatically sent by AVPlayer (https://developer.apple.com/streaming/Whats-new-HLS.pdf). However, after enabling CMCD, our streams occasionally fail with the following error: CoreMediaErrorDomain Error -17383 This issue appears to affect only DRM-protected (FairPlay) streams so far. We activate CMCD via the resource loader of an AVURLAsset, before assigning the item to an AVPlayer. Unfortunately, we haven’t found a reliable way to reproduce the issue, and we’ve been unable to gather any useful diagnostic information. Has anyone else observed this behavior when enabling CMCD on FairPlay streams?
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563
Oct ’25
Airplay selection not working
I'm trying to implement airplay into my app. I can successfully playback sound and trigger the airplay selector sheet. If the target device is a Bluetooth only device I can connect with no problem and stream the audio to the Bluetooth device, but if the audio device is a airplay specific device like a HomePod or an Apple TV when I select it, I get a spinning icon, indicating that it is trying to connect, and eventually it times out and stops without connecting. I don't believe it is an AirPlay audio issue because if I go to a different app, for example a podcast app and select my HomePods for output, and then switch back to my app. My audio will correctly stream to the HomePod. Not only that, I have it so that my icon will change color to indicate that it is connected via airplay and it is correctly indicating that it is connected via AirPlay. But I cannot then disconnect it using the Airplay selector. The issue appears to be in the AirPlay selection side, which I have spent several days attempting to troubleshoot mostly using ChatGPT to suggest code different than what I have to maybe work around the issue. Mostly it is focused on the audio player section, but it doesn't seem like that is really the route that is the problem.
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252
Jun ’25
All boys wanna access Media Library (sung to All Gurls Wanna Have Fun)
Howdy. I'm trying to access media from a users song library and receive: <ICUserIdentityStoreACAccountBackend: 0x148f8af30> Failed to initialize active account, error=Error Domain=ICError Code=-7013 "Client is not entitled to access account store" UserInfo={NSDebugDescription=Client is not entitled to access account store} I'm told I need to add a Media Library Access Capability. Nothing like this shows up in Xcode under Signing & Capabilities > +Capabilities. Also I can't find anything like this in my account in dev.apple.com. How do I enable myself and a test user using another iPhone device to access my music and their music respectively? Thanks!
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332
Jun ’25
How can I locate a UVC camera for PTZ control by AVCaptureDevice.unique_id
I'm writing a program to control a PTZ camera connected via USB. I can get access to target camera's unique_id, and also other infos provided by AVFoundation. But I don't know how to locate my target USB device to send a UVC ControlRequest. There's many Cameras with same VendorID and ProductID connected at a time, so I need a more exact way to find out which device is my target. It looks that the unique_id provided is (locationID<<32|VendorID<<16|ProductID) as hex string, but I'm not sure if I can always assume this behavior won't change. Is there's a document declares how AVFoundation generate the unique_id for USB camera, so I can assume this convert will always work? Or is there's a way to send a PTZ control request to AVCaptureDevice? https://stackoverflow.com/questions/40006908/usb-interface-of-an-avcapturedevice I have seen this similar question. But I'm worrying that Exacting LocationID+VendorID+ProductID from unique_id seems like programming to implementation instead of interface. So, if there's any other better way to control my camera? here's my example code for getting unique_id: // // camera_unique_id_test.mm // // 测试代码:使用C++获取当前系统摄像头的AVCaptureDevice unique_id // // 编译命令: // clang++ -framework AVFoundation -framework CoreMedia -framework Foundation // camera_unique_id_test.mm -o camera_unique_id_test // #include <iostream> #include <string> #include <vector> #import <AVFoundation/AVFoundation.h> #import <Foundation/Foundation.h> struct CameraInfo { std::string uniqueId; }; std::vector<CameraInfo> getAllCameraDevices() { std::vector<CameraInfo> cameras; @autoreleasepool { NSArray<AVCaptureDevice*>* devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo]; AVCaptureDevice* defaultDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; // 遍历所有设备 for (AVCaptureDevice* device in devices) { CameraInfo info; // 获取unique_id info.uniqueId = std::string([device.uniqueID UTF8String]); cameras.push_back(info); } } return cameras; } int main(int argc, char* argv[]) { std::vector<CameraInfo> cameras = getAllCameraDevices(); for (size_t i = 0; i < cameras.size(); i++) { const CameraInfo& camera = cameras[i]; std::cout << " 设备 " << (i + 1) << ":" << std::endl; std::cout << " unique_id: " << camera.uniqueId << std::endl; } return 0; } and here's my code for UVC control: // clang++ -framework Foundation -framework IOKit uvc_test.cpp -o uvc_test #include <iostream> #include <CoreFoundation/CoreFoundation.h> #include <IOKit/IOCFPlugIn.h> #include <IOKit/IOKitLib.h> #include <IOKit/IOMessage.h> #include <IOKit/usb/IOUSBLib.h> #include <IOKit/usb/USB.h> CFStringRef CreateCFStringFromIORegistryKey(io_service_t ioService, const char* key) { CFStringRef keyString = CFStringCreateWithCString(kCFAllocatorDefault, key, kCFStringEncodingUTF8); if (!keyString) return nullptr; CFStringRef result = static_cast<CFStringRef>( IORegistryEntryCreateCFProperty(ioService, keyString, kCFAllocatorDefault, kIORegistryIterateRecursively)); CFRelease(keyString); return result; } std::string GetStringFromIORegistry(io_service_t ioService, const char* key) { CFStringRef cfString = CreateCFStringFromIORegistryKey(ioService, key); if (!cfString) return ""; char buffer[256]; Boolean success = CFStringGetCString(cfString, buffer, sizeof(buffer), kCFStringEncodingUTF8); CFRelease(cfString); return success ? std::string(buffer) : std::string(""); } uint32_t GetUInt32FromIORegistry(io_service_t ioService, const char* key) { CFStringRef keyString = CFStringCreateWithCString(kCFAllocatorDefault, key, kCFStringEncodingUTF8); if (!keyString) return 0; CFNumberRef number = static_cast<CFNumberRef>( IORegistryEntryCreateCFProperty(ioService, keyString, kCFAllocatorDefault, kIORegistryIterateRecursively)); CFRelease(keyString); if (!number) return 0; uint32_t value = 0; CFNumberGetValue(number, kCFNumberSInt32Type, &value); CFRelease(number); return value; } int main() { // Get matching dictionary for USB devices CFMutableDictionaryRef matchingDict = IOServiceMatching(kIOUSBDeviceClassName); // Get iterator for matching services io_iterator_t serviceIterator; IOServiceGetMatchingServices(kIOMasterPortDefault, matchingDict, &serviceIterator); // Iterate through matching devices io_service_t usbService; while ((usbService = IOIteratorNext(serviceIterator))) { uint32_t locationId = GetUInt32FromIORegistry(usbService, "locationID"); uint32_t vendorId = GetUInt32FromIORegistry(usbService, "idVendor"); uint32_t productId = GetUInt32FromIORegistry(usbService, "idProduct"); IOCFPlugInInterface** plugInInterface = nullptr; IOUSBDeviceInterface** deviceInterface = nullptr; SInt32 score; // Get device plugin interface IOCreatePlugInInterfaceForService(usbService, kIOUSBDeviceUserClientTypeID, kIOCFPlugInInterfaceID, &plugInInterface, &score); // Get device interface (*plugInInterface) ->QueryInterface(plugInInterface, CFUUIDGetUUIDBytes(kIOUSBDeviceInterfaceID), (LPVOID*)&deviceInterface); (*plugInInterface)->Release(plugInInterface); // Try to find UVC control interface using CreateInterfaceIterator io_iterator_t interfaceIterator; IOUSBFindInterfaceRequest interfaceRequest; interfaceRequest.bInterfaceClass = kUSBVideoInterfaceClass; // 14 interfaceRequest.bInterfaceSubClass = kUSBVideoControlSubClass; // 1 interfaceRequest.bInterfaceProtocol = kIOUSBFindInterfaceDontCare; interfaceRequest.bAlternateSetting = kIOUSBFindInterfaceDontCare; (*deviceInterface) ->CreateInterfaceIterator(deviceInterface, &interfaceRequest, &interfaceIterator); (*deviceInterface)->Release(deviceInterface); io_service_t usbInterface = IOIteratorNext(interfaceIterator); IOObjectRelease(interfaceIterator); if (usbInterface) { std::cout << "Get UVC device with:" << std::endl; std::cout << "locationId: " << std::hex << locationId << std::endl; std::cout << "vendorId: " << std::hex << vendorId << std::endl; std::cout << "productId: " << std::hex << productId << std::endl << std::endl; IOObjectRelease(usbInterface); } IOObjectRelease(usbService); } IOObjectRelease(serviceIterator); }
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349
Oct ’25
FxPlug SDK 4.3.2 causes dyld errors when loaded on versions of macOS prior to 14.6
FxPlug is one of Apple’s official SDKs, recently updated to version 4.3.2. In theory the SDK should guarantee third-parties can build plug-ins that are backward compatible with older versions of Final Cut Pro, Motion and Compressor. FxPlug SDK includes two frameworks that third-party developers like me end up bundling inside our third-party plugins: FxPlug.framework and PlugInManager.framework. Behind the scenes, the SDK relies on PlugInKit, but the FxPlug.framework provides abstractions so that third-parties don't have to handle the intricacies of XPC directly. The most recent version of FxPlug.framework included with the SDK was possibly built with an error: the Info.plist shows a LSMinimumSystemVersion entry of 14.6, suggesting the binary may have been compiled and linked with MACOSX_DEPLOYMENT_TARGET set to 14.6 by accident. The problem: when older versions of Final Cut Pro or Motion load a third-party plugin (itself built with the appropriate deployment target, macOS 11 or 12, for example) on pre-macOS 14.6, the dynamic linker immediately loads Apple’s own FxPlug.framework, but this causes the process to crash immediately: Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 libobjc.A.dylib 0x7ff81e065955 map_images_nolock + 5399 1 libobjc.A.dylib 0x7ff81e0643d6 map_images + 67 2 dyld 0x10bd551fb invocation function for block in dyld4::RuntimeState::setObjCNotifiers(void (*)(unsigned int, char const* const*, mach_header const* const*), void (*)(char const*, mach_header const*), void (*)(char const*, mach_header const*)) + 275 3 dyld 0x10bd506c9 dyld4::RuntimeState::withLoadersReadLock(void () block_pointer) + 41 4 dyld 0x10bd550e2 dyld4::RuntimeState::setObjCNotifiers(void (*)(unsigned int, char const* const*, mach_header const* const*), void (*)(char const*, mach_header const*), void (*)(char const*, mach_header const*)) + 82 5 dyld 0x10bd68d45 dyld4::APIs::_dyld_objc_notify_register(void (*)(unsigned int, char const* const*, mach_header const* const*), void (*)(char const*, mach_header const*), void (*)(char const*, mach_header const*)) + 79 6 libobjc.A.dylib 0x7ff81e064244 _objc_init + 1279 7 libdispatch.dylib 0x7ff81e01d993 _os_object_init + 13 8 libdispatch.dylib 0x7ff81e02b1b8 libdispatch_init + 311 9 libSystem.B.dylib 0x7ff828fd585f libSystem_initializer + 238 10 dyld 0x10bd5ae4f invocation function for block in dyld4::Loader::findAndRunAllInitializers(dyld4::RuntimeState&) const + 182 11 dyld 0x10bd81aad invocation function for block in dyld3::MachOAnalyzer::forEachInitializer(Diagnostics&, dyld3::MachOAnalyzer::VMAddrConverter const&, void (unsigned int) block_pointer, void const*) const + 242 12 dyld 0x10bd78e26 invocation function for block in dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const + 557 13 dyld 0x10bd47db3 dyld3::MachOFile::forEachLoadCommand(Diagnostics&, void (load_command const*, bool&) block_pointer) const + 129 14 dyld 0x10bd78bb7 dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const + 179 15 dyld 0x10bd81604 dyld3::MachOAnalyzer::forEachInitializer(Diagnostics&, dyld3::MachOAnalyzer::VMAddrConverter const&, void (unsigned int) block_pointer, void const*) const + 466 16 dyld 0x10bd5ad82 dyld4::Loader::findAndRunAllInitializers(dyld4::RuntimeState&) const + 144 17 dyld 0x10bd6165a dyld4::PrebuiltLoader::runInitializers(dyld4::RuntimeState&) const + 30 18 dyld 0x10bd6e76e dyld4::APIs::runAllInitializersForMain() + 38 19 dyld 0x10bd4c38d dyld4::prepare(dyld4::APIs&, dyld3::MachOAnalyzer const*) + 3443 20 dyld 0x10bd4b4e4 start + 388 Can someone at Apple with the right domain expertise confirm that this is the type of crash you would see because the framework was built assuming it would run on macOS 14.6 and later, and when facing an older environment (e.g. ObjC runtime) it lacks extra code that would ensure backward compatibility with the earlier ObjC runtime found on macOS 12.x?
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200
Jun ’25
AVAssetWriterInputTaggedPixelBufferGroupAdaptor Hanging With Tagged Buffers
We've successfully implemented an AVAssetWriter to produce HLS streams (all code is Objective-C++ for interop with existing codebase) but are struggling to extend the operations to use tagged buffers. We're starting to wonder if the tagged buffers required for an MV-HEVC signal are fully supported when producing HLS segments in a live-stream setting. We generate a live stream of data using something like: UTType *t = [UTType typeWithIdentifier:AVFileTypeMPEG4]; m_writter = [[AVAssetWriter alloc] initWithContentType:t]; // - videoHint describes HEVC and width/height // - m_videoConfig includes compression settings and, when using MV-HEVC, // the correct keys are added (i.e. kVTCompressionPropertyKey_MVHEVCVideoLayerIDs) // The app was throwing an exception without these which was // useful to know when we got the configuration right. m_video = [[AVAssetWriterInput alloc] initWithMediaType:AVMediaTypeVideo outputSettings:m_videoConfig sourceFormatHint:videoHint]; For either path we're producing CVPixelBufferRefs that contain the raw pixel information (i.e. 32BGRA) so we use an adapter to make that as simple as possible. If we use a single view and a AVAssetWriterInputPixelBufferAdaptor things work out very well. We produce segments and the delegate is called. However, if we use the AVAssetWriterInputTaggedPixelBufferGroupAdaptor as exampled in the SideBySideToMVHEVC demo project, things go poorly. We create the tagged buffers with something like: CMTagCollectionRef collections[2]; CMTag leftTags[] = { CMTagMakeWithSInt64Value( kCMTagCategory_VideoLayerID, (int64_t)0), CMTagMakeWithSInt64Value( kCMTagCategory_StereoView, kCMStereoView_LeftEye) }; CMTagCollectionCreate( kCFAllocatorDefault, leftTags, 2, &(collections[0]) ); CMTag rightTags[] = { CMTagMakeWithSInt64Value( kCMTagCategory_VideoLayerID, (int64_t)1), CMTagMakeWithSInt64Value( kCMTagCategory_StereoView, kCMStereoView_RightEye) }; CMTagCollectionCreate( kCFAllocatorDefault, rightTags, 2, &(collections[1]) ); CFArrayRef tagCollections = CFArrayCreate( kCFAllocatorDefault, (const void **)collections, 2, &kCFTypeArrayCallBacks ); CVPixelBufferRef buffers[] = {*b, *alt}; CFArrayRef b = CFArrayCreate( kCFAllocatorDefault, (const void **)buffers, 2, &kCFTypeArrayCallBacks ); CMTaggedBufferGroupRef bufferGroup; OSStatus res = CMTaggedBufferGroupCreate( kCFAllocatorDefault, tagCollections, b, &bufferGroup ); Perhaps there's something about this OBJC code that I've buggered up? Hopefully! Anyways, when I submit this tagged bugger group to the adaptor: if (![mvVideoAdapter appendTaggedPixelBufferGroup:bufferGroup withPresentationTime:pts]) { // report error... } Appending does not raise any errors - eventually it just hangs on us and we never return from it... Real Issue: So either: The delegate assigned to the AVAssetWriter doesn't fire its assetWriter callback which should produce the segments The adapter hangs on the appendTaggedPixelBufferGroup before a segment is ready to be completed (but succeeds for a number of buffer groups before this happens). This is the same delegate class that's assigned to the non multi view code path if MV-HEVC is turned off which works perfectly.
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120
Apr ’25
Background GPU access in iOS 26 for iPhones
We build mobile apps for creators to edit their videos. Post editing the video, the creator has to export the video so that it can be uploaded to Youtube. The export is a time consuming and GPU intensive process. The creator can exit the app due to various reasons like receiving the call, putting the app in background etc. This causes the export to fail :( Keeping this limitation in mind there was an announcement from Apple that with the IOS 26 launch would start to support background GPU access. Here is the official documentation: https://developer.apple.com/documentation/BundleResources/Entitlements/com.apple.developer.background-tasks.continued-processing.gpu When we tried using this feature, we were not able to get it to work on IOS 26. We stumbled upon this ticket(https://developer.apple.com/forums/thread/797538?answerId=854825022#854825022) in the Apple Developer forum, in which possibly an Apple engineer claims it is supported ONLY for iPadOS 26. This is a very big bummer for us. 96% of the users are on iPhone(compared to iPad), and if we refer to the official documentation above, it claims that this feature should work on IOS 26. This feature is extremely important for having the best user experience and reducing user frustration and will be useful for other video editing apps. Looking forward to a resolution.
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254
Oct ’25
Is AVAudioPCMFormatFloat32 required for playing a buffer with AVAudioEngine / AVAudioPlayerNode
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).
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1.1k
Oct ’25
Metal CIKernel instances with arbitrarily structured data arguments
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
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534
Oct ’25
Take correctly sized screenshots with ScreenCaptureKit
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)) } } }
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975
Oct ’25
Audio player app is silent if device connected via CarPlay
I have a SwiftUI app - (https://youtu.be/VbAfUk_eYl0?si=JxUBh0Bpb-vc1E1U) - which I thought was almost ready for release - a manager for airdropped audio files from Logic Pro or other music creation applications. It uses AVAudioEngine and AVAudioPlayerNode to play audio, and the MediaPlayer API to integrate with car audio and similar, all of which works well. It does not currently have an explicit CarPlay integration (and I'm slightly horrified at the amount of work that is going to require). I had the good or bad luck of getting a loaner car with carplay while mine is being repaired yesterday, and lo and behold, when connected to the vehicle via CarPlay, there is no audio output in the vehicle at all. The now playing panel correctly shows the information my app provides about the currently playing song; the player node believes it is playing, the AVAudioSession is configured as it should be. But there is no sound. Obviously I cannot ship it in this state. I've tried fiddling with the parameters the AVAudioSession is configured with, in case there was some parameter that was preventing audio output, to no avail - currently: var options = AVAudioSession.CategoryOptions() options.insert(.allowAirPlay) options.insert(.allowBluetooth) options.insert(.allowBluetoothA2DP) try session.setCategory(.playback, mode: .default, options: options) try? session.setPreferredIOBufferDuration(0.002) // ~96 samples at 44.1kHz try? session.setPrefersNoInterruptionsFromSystemAlerts(true) try? session.setPrefersInterruptionOnRouteDisconnect(false) try session.setActive(true, options: [.notifyOthersOnDeactivation]) All diagnostics within the app show the player operating correctly - files are played and flushed; AVAudioPlayerNodeCompletionCallbacks are called when they should be. But the output is not audible in the vehicle. I would much prefer to ship this app without full-blown CarPlay integration, but with working audio when connected via CarPlay, and work on full CarPlay integration for the next release. Is there some secret handshake I am just missing to make this work?
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245
Mar ’25
MusicKit API returns 500 Internal Server Error despite valid JWT and setup
My app is properly configured with MusicKit. I've generated a JWT using my valid credentials (Team ID, Key ID, private key), and I’ve ensured the time settings are correct via NTP. When I call: https://api.music.apple.com/v1/catalog/jp/search?term=ado&amp;types=songs I consistently receive a 500 Internal Server Error. The JWT is generated using ES256 with valid iat and exp values. I’ve confirmed the token decodes properly using jwt.io, and it's passed via the Authorization: Bearer header. Things I’ve confirmed: Key ID, Team ID, private key are correct App ID is configured with MusicKit capability JWT is generated and signed correctly macOS time is synced via NTP Used both curl and Python to test — same result Is there anything else I should check on the Apple Developer Console (like App ID, Certificates, or provisioning profile)? Or could this be a backend issue on Apple’s side? Any guidance would be appreciated.
4
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497
Nov ’25
How to disable/hide Audio Controls on lock screen from WkWebView
Hi, I am trying to remove the audio controls for my app on the lock screen. Since I use WKWebView, there are 3 audio tags in my html and I play and pause em via JS. However, if I do not play any sound since app launch, there are no audio controls on the lock screen. But if I play one of those 3 files (they are even less then 3 Sec sound effects e.g. for buttons) the audio controls appears on lock screen. Note even when the sounds on pause() or not playing they were listed on the lock screen. What I have tried so far without success MPNowPlayingInfoCenter.default().nowPlayingInfo = [:] and ``try audioSession.setCategory(.playback, mode: .default, options: []) try audioSession.setActive(false, options: .notifyOthersOnDeactivation)`` and UIApplication.shared.endReceivingRemoteControlEvents() Another problem is that the app scales with iOS system settings "display zoom". Is there a way to deny it? It is latest Xcode verion 16.3 and iOS 18. I have no background mode in my Capabilities. Nothing worked so far. Has anyone an idea? Greetings
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2
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135
Activity
May ’25
Delete songs from playlist via Apple Music API
I use htttps://api.music.apple.com/v1/me/library/playlists/${playlistId}/tracks to add tracks to a playlist I created. How do I DELETE tracks from the playlist? The documentation does not mention a method for this. I have tried calling DELETE methods in various combinations but nothing seems to work. Is this possible?
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3
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495
Activity
Oct ’25
CVPixelBufferCreate EXC_BAD_ACCESS
I am doing something similar to this post Within an AVCaptureDataOutputSynchronizerDelegate method, I create a pixelBuffer using CVPixelBufferCreate with the following attributes: kCVPixelBufferIOSurfacePropertiesKey as String: true, kCVPixelBufferIOSurfaceOpenGLESTextureCompatibilityKey as String: true When I copy the data from the vImagePixelBuffer "rotatedImageBuffer", I get the following error: Thread 10: EXC_BAD_ACCESS (code=1, address=0x14caa8000) I get the same error with memcpy and data.copyBytes (not running them at the same time obviously). If I use CVPixelBufferCreateWithBytes, I do not get this error. However, CVPixelBufferCreateWithBytes does not let you include attributes (see linked post above). I am using vImage because I need the original CVPixelBuffer from the camera output and a rotated version with a different color scheme. // Copy to pixel buffer let attributes: NSDictionary = [ true : kCVPixelBufferIOSurfacePropertiesKey, true : kCVPixelBufferIOSurfaceOpenGLESTextureCompatibilityKey, ] var colorBuffer: CVPixelBuffer? let status = CVPixelBufferCreate(kCFAllocatorDefault, Int(rotatedImageBuffer.width), Int(rotatedImageBuffer.height), kCVPixelFormatType_32BGRA, attributes, &colorBuffer) //let status = CVPixelBufferCreateWithBytes(kCFAllocatorDefault, Int(rotatedImageBuffer.width), Int(rotatedImageBuffer.height), kCVPixelFormatType_32BGRA, rotatedImageBuffer.data, rotatedImageBuffer.rowBytes, nil, nil, attributes as CFDictionary, &colorBuffer) // does NOT produce error, but also does not have attributes guard status == kCVReturnSuccess, let colorBuffer = colorBuffer else { print("Failed to create buffer") return } let lockFlags = CVPixelBufferLockFlags(rawValue: 0) guard kCVReturnSuccess == CVPixelBufferLockBaseAddress(colorBuffer, lockFlags) else { print("Failed to lock base address") return } let colorBufferMemory = CVPixelBufferGetBaseAddress(colorBuffer)! let data = Data(bytes: rotatedImageBuffer.data, count: rotatedImageBuffer.rowBytes * Int(rotatedImageBuffer.height)) data.copyBytes(to: colorBufferMemory.assumingMemoryBound(to: UInt8.self), count: data.count) // Fails here //memcpy(colorBufferMemory, rotatedImageBuffer.data, rotatedImageBuffer.rowBytes * Int(rotatedImageBuffer.height)) // Also produces the same error CVPixelBufferUnlockBaseAddress(colorBuffer, lockFlags)
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310
Activity
Apr ’25
AVB Support for the AVnu MILAN Conventions
The AVB AVnu MILAN Convention has a groweing Population. Many big companies (Cisco, Meyer Sound, d&b Audio, l‘acoustics, Presonus, digico etc.) implements the AVB AVnu Milan Standards. Is there a plan on the Apple side to also implement AVnu Milan on top of the AVB Protocol? The advantage for Apple Sound would be a great Integration in the professionell Audio market and a more stable intergration on top of the AVB protocol. The atdecc work, but Not that stable.
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178
Activity
Oct ’25
Apple watch for child
Hi, my daughter was given an Apple Watch due to her grandfather's passing. It is not GPS/cellular, and we cannot connect it to her Apple ID because of this. It doesn't seem right to leave her logged in to his Apple ID, but we are currently out of options. Is there a workaround to this? When I try to set her up from my phone, it tells me that the watch must have GPS/cellular to set it up. Why? Am I missing something?
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3
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170
Activity
Jun ’25
Crackling/Popping sound when using AVAudioUnitTimePitch
I have a simple AVAudioEngine graph as follows: AVAudioPlayerNode -> AVAudioUnitEQ -> AVAudioUnitTimePitch -> AVAudioUnitReverb -> Main mixer node of AVAudioEngine. I noticed that whenever I have AVAudioUnitTimePitch or AVAudioUnitVarispeed in the graph, I noticed a very distinct crackling/popping sound in my Airpods Pro 2 when starting up the engine and playing the AVAudioPlayerNode and unable to find the reason why this is happening. When I remove the node, the crackling completely goes away. How do I fix this problem since i need the user to be able to control the pitch and rate of the audio during playback. import AVKit @Observable @MainActor class AudioEngineManager { nonisolated private let engine = AVAudioEngine() private let playerNode = AVAudioPlayerNode() private let reverb = AVAudioUnitReverb() private let pitch = AVAudioUnitTimePitch() private let eq = AVAudioUnitEQ(numberOfBands: 10) private var audioFile: AVAudioFile? private var fadePlayPauseTask: Task<Void, Error>? private var playPauseCurrentFadeTime: Double = 0 init() { setupAudioEngine() } private func setupAudioEngine() { guard let url = Bundle.main.url(forResource: "Song name goes here", withExtension: "mp3") else { print("Audio file not found") return } do { audioFile = try AVAudioFile(forReading: url) } catch { print("Failed to load audio file: \(error)") return } reverb.loadFactoryPreset(.mediumHall) reverb.wetDryMix = 50 pitch.pitch = 0 // Increase pitch by 500 cents (5 semitones) engine.attach(playerNode) engine.attach(pitch) engine.attach(reverb) engine.attach(eq) // Connect: player -> pitch -> reverb -> output engine.connect(playerNode, to: eq, format: audioFile?.processingFormat) engine.connect(eq, to: pitch, format: audioFile?.processingFormat) engine.connect(pitch, to: reverb, format: audioFile?.processingFormat) engine.connect(reverb, to: engine.mainMixerNode, format: audioFile?.processingFormat) } func prepare() { guard let audioFile else { return } playerNode.scheduleFile(audioFile, at: nil) } func play() { DispatchQueue.global().async { [weak self] in guard let self else { return } engine.prepare() try? engine.start() DispatchQueue.main.async { [weak self] in guard let self else { return } playerNode.play() fadePlayPauseTask?.cancel() playPauseCurrentFadeTime = 0 fadePlayPauseTask = Task { [weak self] in guard let self else { return } while true { let volume = updateVolume(for: playPauseCurrentFadeTime / 0.1, rising: true) // Ramp up volume until 1 is reached if volume >= 1 { break } engine.mainMixerNode.outputVolume = volume try await Task.sleep(for: .milliseconds(10)) playPauseCurrentFadeTime += 0.01 } engine.mainMixerNode.outputVolume = 1 } } } } func pause() { fadePlayPauseTask?.cancel() playPauseCurrentFadeTime = 0 fadePlayPauseTask = Task { [weak self] in guard let self else { return } while true { let volume = updateVolume(for: playPauseCurrentFadeTime / 0.1, rising: false) // Ramp down volume until 0 is reached if volume <= 0 { break } engine.mainMixerNode.outputVolume = volume try await Task.sleep(for: .milliseconds(10)) playPauseCurrentFadeTime += 0.01 } engine.mainMixerNode.outputVolume = 0 playerNode.pause() // Shut down engine once ramp down completes DispatchQueue.global().async { [weak self] in guard let self else { return } engine.pause() } } } private func updateVolume(for x: Double, rising: Bool) -> Float { if rising { // Fade in return Float(pow(x, 2) * (3.0 - 2.0 * (x))) } else { // Fade out return Float(1 - (pow(x, 2) * (3.0 - 2.0 * (x)))) } } func setPitch(_ value: Float) { pitch.pitch = value } func setReverbMix(_ value: Float) { reverb.wetDryMix = value } } struct ContentView: View { @State private var audioManager = AudioEngineManager() @State private var pitch: Float = 0 @State private var reverb: Float = 0 var body: some View { VStack(spacing: 20) { Text("🎵 Audio Player with Reverb & Pitch") .font(.title2) HStack { Button("Prepare") { audioManager.prepare() } Button("Play") { audioManager.play() } .padding() .background(Color.green) .foregroundColor(.white) .cornerRadius(10) Button("Pause") { audioManager.pause() } .padding() .background(Color.red) .foregroundColor(.white) .cornerRadius(10) } VStack { Text("Pitch: \(Int(pitch)) cents") Slider(value: $pitch, in: -2400...2400, step: 100) { _ in audioManager.setPitch(pitch) } } VStack { Text("Reverb Mix: \(Int(reverb))%") Slider(value: $reverb, in: 0...100, step: 1) { _ in audioManager.setReverbMix(reverb) } } } .padding() } }
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282
Activity
Apr ’25
WorldCaptureKit
Does the library exists in xCode 16.4? "import WorldCaptureKit" gives error "No such module 'WorldCaptureKit'". And I do not find any information about the library in the apple documentation. But AI keeps suggesting me to use the library
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127
Activity
Jun ’25
Playback Issues for DRM content when sending CMCD
Since iOS and tvOS 18, CMCD can now be automatically sent by AVPlayer (https://developer.apple.com/streaming/Whats-new-HLS.pdf). However, after enabling CMCD, our streams occasionally fail with the following error: CoreMediaErrorDomain Error -17383 This issue appears to affect only DRM-protected (FairPlay) streams so far. We activate CMCD via the resource loader of an AVURLAsset, before assigning the item to an AVPlayer. Unfortunately, we haven’t found a reliable way to reproduce the issue, and we’ve been unable to gather any useful diagnostic information. Has anyone else observed this behavior when enabling CMCD on FairPlay streams?
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3
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563
Activity
Oct ’25
Airplay selection not working
I'm trying to implement airplay into my app. I can successfully playback sound and trigger the airplay selector sheet. If the target device is a Bluetooth only device I can connect with no problem and stream the audio to the Bluetooth device, but if the audio device is a airplay specific device like a HomePod or an Apple TV when I select it, I get a spinning icon, indicating that it is trying to connect, and eventually it times out and stops without connecting. I don't believe it is an AirPlay audio issue because if I go to a different app, for example a podcast app and select my HomePods for output, and then switch back to my app. My audio will correctly stream to the HomePod. Not only that, I have it so that my icon will change color to indicate that it is connected via airplay and it is correctly indicating that it is connected via AirPlay. But I cannot then disconnect it using the Airplay selector. The issue appears to be in the AirPlay selection side, which I have spent several days attempting to troubleshoot mostly using ChatGPT to suggest code different than what I have to maybe work around the issue. Mostly it is focused on the audio player section, but it doesn't seem like that is really the route that is the problem.
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252
Activity
Jun ’25
All boys wanna access Media Library (sung to All Gurls Wanna Have Fun)
Howdy. I'm trying to access media from a users song library and receive: <ICUserIdentityStoreACAccountBackend: 0x148f8af30> Failed to initialize active account, error=Error Domain=ICError Code=-7013 "Client is not entitled to access account store" UserInfo={NSDebugDescription=Client is not entitled to access account store} I'm told I need to add a Media Library Access Capability. Nothing like this shows up in Xcode under Signing & Capabilities > +Capabilities. Also I can't find anything like this in my account in dev.apple.com. How do I enable myself and a test user using another iPhone device to access my music and their music respectively? Thanks!
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332
Activity
Jun ’25
SIGABORT with ExtAudioFileWrite and .m4a file
Hi, I am getting into a trap. Please check stack-trace, howto fix this? regards, Joël stack-trace with ExtAudioFileWrite
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2
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926
Activity
Jun ’25
How can I locate a UVC camera for PTZ control by AVCaptureDevice.unique_id
I'm writing a program to control a PTZ camera connected via USB. I can get access to target camera's unique_id, and also other infos provided by AVFoundation. But I don't know how to locate my target USB device to send a UVC ControlRequest. There's many Cameras with same VendorID and ProductID connected at a time, so I need a more exact way to find out which device is my target. It looks that the unique_id provided is (locationID<<32|VendorID<<16|ProductID) as hex string, but I'm not sure if I can always assume this behavior won't change. Is there's a document declares how AVFoundation generate the unique_id for USB camera, so I can assume this convert will always work? Or is there's a way to send a PTZ control request to AVCaptureDevice? https://stackoverflow.com/questions/40006908/usb-interface-of-an-avcapturedevice I have seen this similar question. But I'm worrying that Exacting LocationID+VendorID+ProductID from unique_id seems like programming to implementation instead of interface. So, if there's any other better way to control my camera? here's my example code for getting unique_id: // // camera_unique_id_test.mm // // 测试代码:使用C++获取当前系统摄像头的AVCaptureDevice unique_id // // 编译命令: // clang++ -framework AVFoundation -framework CoreMedia -framework Foundation // camera_unique_id_test.mm -o camera_unique_id_test // #include <iostream> #include <string> #include <vector> #import <AVFoundation/AVFoundation.h> #import <Foundation/Foundation.h> struct CameraInfo { std::string uniqueId; }; std::vector<CameraInfo> getAllCameraDevices() { std::vector<CameraInfo> cameras; @autoreleasepool { NSArray<AVCaptureDevice*>* devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo]; AVCaptureDevice* defaultDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; // 遍历所有设备 for (AVCaptureDevice* device in devices) { CameraInfo info; // 获取unique_id info.uniqueId = std::string([device.uniqueID UTF8String]); cameras.push_back(info); } } return cameras; } int main(int argc, char* argv[]) { std::vector<CameraInfo> cameras = getAllCameraDevices(); for (size_t i = 0; i < cameras.size(); i++) { const CameraInfo& camera = cameras[i]; std::cout << " 设备 " << (i + 1) << ":" << std::endl; std::cout << " unique_id: " << camera.uniqueId << std::endl; } return 0; } and here's my code for UVC control: // clang++ -framework Foundation -framework IOKit uvc_test.cpp -o uvc_test #include <iostream> #include <CoreFoundation/CoreFoundation.h> #include <IOKit/IOCFPlugIn.h> #include <IOKit/IOKitLib.h> #include <IOKit/IOMessage.h> #include <IOKit/usb/IOUSBLib.h> #include <IOKit/usb/USB.h> CFStringRef CreateCFStringFromIORegistryKey(io_service_t ioService, const char* key) { CFStringRef keyString = CFStringCreateWithCString(kCFAllocatorDefault, key, kCFStringEncodingUTF8); if (!keyString) return nullptr; CFStringRef result = static_cast<CFStringRef>( IORegistryEntryCreateCFProperty(ioService, keyString, kCFAllocatorDefault, kIORegistryIterateRecursively)); CFRelease(keyString); return result; } std::string GetStringFromIORegistry(io_service_t ioService, const char* key) { CFStringRef cfString = CreateCFStringFromIORegistryKey(ioService, key); if (!cfString) return ""; char buffer[256]; Boolean success = CFStringGetCString(cfString, buffer, sizeof(buffer), kCFStringEncodingUTF8); CFRelease(cfString); return success ? std::string(buffer) : std::string(""); } uint32_t GetUInt32FromIORegistry(io_service_t ioService, const char* key) { CFStringRef keyString = CFStringCreateWithCString(kCFAllocatorDefault, key, kCFStringEncodingUTF8); if (!keyString) return 0; CFNumberRef number = static_cast<CFNumberRef>( IORegistryEntryCreateCFProperty(ioService, keyString, kCFAllocatorDefault, kIORegistryIterateRecursively)); CFRelease(keyString); if (!number) return 0; uint32_t value = 0; CFNumberGetValue(number, kCFNumberSInt32Type, &value); CFRelease(number); return value; } int main() { // Get matching dictionary for USB devices CFMutableDictionaryRef matchingDict = IOServiceMatching(kIOUSBDeviceClassName); // Get iterator for matching services io_iterator_t serviceIterator; IOServiceGetMatchingServices(kIOMasterPortDefault, matchingDict, &serviceIterator); // Iterate through matching devices io_service_t usbService; while ((usbService = IOIteratorNext(serviceIterator))) { uint32_t locationId = GetUInt32FromIORegistry(usbService, "locationID"); uint32_t vendorId = GetUInt32FromIORegistry(usbService, "idVendor"); uint32_t productId = GetUInt32FromIORegistry(usbService, "idProduct"); IOCFPlugInInterface** plugInInterface = nullptr; IOUSBDeviceInterface** deviceInterface = nullptr; SInt32 score; // Get device plugin interface IOCreatePlugInInterfaceForService(usbService, kIOUSBDeviceUserClientTypeID, kIOCFPlugInInterfaceID, &plugInInterface, &score); // Get device interface (*plugInInterface) ->QueryInterface(plugInInterface, CFUUIDGetUUIDBytes(kIOUSBDeviceInterfaceID), (LPVOID*)&deviceInterface); (*plugInInterface)->Release(plugInInterface); // Try to find UVC control interface using CreateInterfaceIterator io_iterator_t interfaceIterator; IOUSBFindInterfaceRequest interfaceRequest; interfaceRequest.bInterfaceClass = kUSBVideoInterfaceClass; // 14 interfaceRequest.bInterfaceSubClass = kUSBVideoControlSubClass; // 1 interfaceRequest.bInterfaceProtocol = kIOUSBFindInterfaceDontCare; interfaceRequest.bAlternateSetting = kIOUSBFindInterfaceDontCare; (*deviceInterface) ->CreateInterfaceIterator(deviceInterface, &interfaceRequest, &interfaceIterator); (*deviceInterface)->Release(deviceInterface); io_service_t usbInterface = IOIteratorNext(interfaceIterator); IOObjectRelease(interfaceIterator); if (usbInterface) { std::cout << "Get UVC device with:" << std::endl; std::cout << "locationId: " << std::hex << locationId << std::endl; std::cout << "vendorId: " << std::hex << vendorId << std::endl; std::cout << "productId: " << std::hex << productId << std::endl << std::endl; IOObjectRelease(usbInterface); } IOObjectRelease(usbService); } IOObjectRelease(serviceIterator); }
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349
Activity
Oct ’25
FxPlug SDK 4.3.2 causes dyld errors when loaded on versions of macOS prior to 14.6
FxPlug is one of Apple’s official SDKs, recently updated to version 4.3.2. In theory the SDK should guarantee third-parties can build plug-ins that are backward compatible with older versions of Final Cut Pro, Motion and Compressor. FxPlug SDK includes two frameworks that third-party developers like me end up bundling inside our third-party plugins: FxPlug.framework and PlugInManager.framework. Behind the scenes, the SDK relies on PlugInKit, but the FxPlug.framework provides abstractions so that third-parties don't have to handle the intricacies of XPC directly. The most recent version of FxPlug.framework included with the SDK was possibly built with an error: the Info.plist shows a LSMinimumSystemVersion entry of 14.6, suggesting the binary may have been compiled and linked with MACOSX_DEPLOYMENT_TARGET set to 14.6 by accident. The problem: when older versions of Final Cut Pro or Motion load a third-party plugin (itself built with the appropriate deployment target, macOS 11 or 12, for example) on pre-macOS 14.6, the dynamic linker immediately loads Apple’s own FxPlug.framework, but this causes the process to crash immediately: Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 libobjc.A.dylib 0x7ff81e065955 map_images_nolock + 5399 1 libobjc.A.dylib 0x7ff81e0643d6 map_images + 67 2 dyld 0x10bd551fb invocation function for block in dyld4::RuntimeState::setObjCNotifiers(void (*)(unsigned int, char const* const*, mach_header const* const*), void (*)(char const*, mach_header const*), void (*)(char const*, mach_header const*)) + 275 3 dyld 0x10bd506c9 dyld4::RuntimeState::withLoadersReadLock(void () block_pointer) + 41 4 dyld 0x10bd550e2 dyld4::RuntimeState::setObjCNotifiers(void (*)(unsigned int, char const* const*, mach_header const* const*), void (*)(char const*, mach_header const*), void (*)(char const*, mach_header const*)) + 82 5 dyld 0x10bd68d45 dyld4::APIs::_dyld_objc_notify_register(void (*)(unsigned int, char const* const*, mach_header const* const*), void (*)(char const*, mach_header const*), void (*)(char const*, mach_header const*)) + 79 6 libobjc.A.dylib 0x7ff81e064244 _objc_init + 1279 7 libdispatch.dylib 0x7ff81e01d993 _os_object_init + 13 8 libdispatch.dylib 0x7ff81e02b1b8 libdispatch_init + 311 9 libSystem.B.dylib 0x7ff828fd585f libSystem_initializer + 238 10 dyld 0x10bd5ae4f invocation function for block in dyld4::Loader::findAndRunAllInitializers(dyld4::RuntimeState&) const + 182 11 dyld 0x10bd81aad invocation function for block in dyld3::MachOAnalyzer::forEachInitializer(Diagnostics&, dyld3::MachOAnalyzer::VMAddrConverter const&, void (unsigned int) block_pointer, void const*) const + 242 12 dyld 0x10bd78e26 invocation function for block in dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const + 557 13 dyld 0x10bd47db3 dyld3::MachOFile::forEachLoadCommand(Diagnostics&, void (load_command const*, bool&) block_pointer) const + 129 14 dyld 0x10bd78bb7 dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const + 179 15 dyld 0x10bd81604 dyld3::MachOAnalyzer::forEachInitializer(Diagnostics&, dyld3::MachOAnalyzer::VMAddrConverter const&, void (unsigned int) block_pointer, void const*) const + 466 16 dyld 0x10bd5ad82 dyld4::Loader::findAndRunAllInitializers(dyld4::RuntimeState&) const + 144 17 dyld 0x10bd6165a dyld4::PrebuiltLoader::runInitializers(dyld4::RuntimeState&) const + 30 18 dyld 0x10bd6e76e dyld4::APIs::runAllInitializersForMain() + 38 19 dyld 0x10bd4c38d dyld4::prepare(dyld4::APIs&, dyld3::MachOAnalyzer const*) + 3443 20 dyld 0x10bd4b4e4 start + 388 Can someone at Apple with the right domain expertise confirm that this is the type of crash you would see because the framework was built assuming it would run on macOS 14.6 and later, and when facing an older environment (e.g. ObjC runtime) it lacks extra code that would ensure backward compatibility with the earlier ObjC runtime found on macOS 12.x?
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200
Activity
Jun ’25
AVAssetWriterInputTaggedPixelBufferGroupAdaptor Hanging With Tagged Buffers
We've successfully implemented an AVAssetWriter to produce HLS streams (all code is Objective-C++ for interop with existing codebase) but are struggling to extend the operations to use tagged buffers. We're starting to wonder if the tagged buffers required for an MV-HEVC signal are fully supported when producing HLS segments in a live-stream setting. We generate a live stream of data using something like: UTType *t = [UTType typeWithIdentifier:AVFileTypeMPEG4]; m_writter = [[AVAssetWriter alloc] initWithContentType:t]; // - videoHint describes HEVC and width/height // - m_videoConfig includes compression settings and, when using MV-HEVC, // the correct keys are added (i.e. kVTCompressionPropertyKey_MVHEVCVideoLayerIDs) // The app was throwing an exception without these which was // useful to know when we got the configuration right. m_video = [[AVAssetWriterInput alloc] initWithMediaType:AVMediaTypeVideo outputSettings:m_videoConfig sourceFormatHint:videoHint]; For either path we're producing CVPixelBufferRefs that contain the raw pixel information (i.e. 32BGRA) so we use an adapter to make that as simple as possible. If we use a single view and a AVAssetWriterInputPixelBufferAdaptor things work out very well. We produce segments and the delegate is called. However, if we use the AVAssetWriterInputTaggedPixelBufferGroupAdaptor as exampled in the SideBySideToMVHEVC demo project, things go poorly. We create the tagged buffers with something like: CMTagCollectionRef collections[2]; CMTag leftTags[] = { CMTagMakeWithSInt64Value( kCMTagCategory_VideoLayerID, (int64_t)0), CMTagMakeWithSInt64Value( kCMTagCategory_StereoView, kCMStereoView_LeftEye) }; CMTagCollectionCreate( kCFAllocatorDefault, leftTags, 2, &(collections[0]) ); CMTag rightTags[] = { CMTagMakeWithSInt64Value( kCMTagCategory_VideoLayerID, (int64_t)1), CMTagMakeWithSInt64Value( kCMTagCategory_StereoView, kCMStereoView_RightEye) }; CMTagCollectionCreate( kCFAllocatorDefault, rightTags, 2, &(collections[1]) ); CFArrayRef tagCollections = CFArrayCreate( kCFAllocatorDefault, (const void **)collections, 2, &kCFTypeArrayCallBacks ); CVPixelBufferRef buffers[] = {*b, *alt}; CFArrayRef b = CFArrayCreate( kCFAllocatorDefault, (const void **)buffers, 2, &kCFTypeArrayCallBacks ); CMTaggedBufferGroupRef bufferGroup; OSStatus res = CMTaggedBufferGroupCreate( kCFAllocatorDefault, tagCollections, b, &bufferGroup ); Perhaps there's something about this OBJC code that I've buggered up? Hopefully! Anyways, when I submit this tagged bugger group to the adaptor: if (![mvVideoAdapter appendTaggedPixelBufferGroup:bufferGroup withPresentationTime:pts]) { // report error... } Appending does not raise any errors - eventually it just hangs on us and we never return from it... Real Issue: So either: The delegate assigned to the AVAssetWriter doesn't fire its assetWriter callback which should produce the segments The adapter hangs on the appendTaggedPixelBufferGroup before a segment is ready to be completed (but succeeds for a number of buffer groups before this happens). This is the same delegate class that's assigned to the non multi view code path if MV-HEVC is turned off which works perfectly.
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120
Activity
Apr ’25
Background GPU access in iOS 26 for iPhones
We build mobile apps for creators to edit their videos. Post editing the video, the creator has to export the video so that it can be uploaded to Youtube. The export is a time consuming and GPU intensive process. The creator can exit the app due to various reasons like receiving the call, putting the app in background etc. This causes the export to fail :( Keeping this limitation in mind there was an announcement from Apple that with the IOS 26 launch would start to support background GPU access. Here is the official documentation: https://developer.apple.com/documentation/BundleResources/Entitlements/com.apple.developer.background-tasks.continued-processing.gpu When we tried using this feature, we were not able to get it to work on IOS 26. We stumbled upon this ticket(https://developer.apple.com/forums/thread/797538?answerId=854825022#854825022) in the Apple Developer forum, in which possibly an Apple engineer claims it is supported ONLY for iPadOS 26. This is a very big bummer for us. 96% of the users are on iPhone(compared to iPad), and if we refer to the official documentation above, it claims that this feature should work on IOS 26. This feature is extremely important for having the best user experience and reducing user frustration and will be useful for other video editing apps. Looking forward to a resolution.
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254
Activity
Oct ’25
Is AVAudioPCMFormatFloat32 required for playing a buffer with AVAudioEngine / AVAudioPlayerNode
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).
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1.1k
Activity
Oct ’25
Metal CIKernel instances with arbitrarily structured data arguments
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
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534
Activity
Oct ’25
Take correctly sized screenshots with ScreenCaptureKit
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)) } } }
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975
Activity
Oct ’25
Audio player app is silent if device connected via CarPlay
I have a SwiftUI app - (https://youtu.be/VbAfUk_eYl0?si=JxUBh0Bpb-vc1E1U) - which I thought was almost ready for release - a manager for airdropped audio files from Logic Pro or other music creation applications. It uses AVAudioEngine and AVAudioPlayerNode to play audio, and the MediaPlayer API to integrate with car audio and similar, all of which works well. It does not currently have an explicit CarPlay integration (and I'm slightly horrified at the amount of work that is going to require). I had the good or bad luck of getting a loaner car with carplay while mine is being repaired yesterday, and lo and behold, when connected to the vehicle via CarPlay, there is no audio output in the vehicle at all. The now playing panel correctly shows the information my app provides about the currently playing song; the player node believes it is playing, the AVAudioSession is configured as it should be. But there is no sound. Obviously I cannot ship it in this state. I've tried fiddling with the parameters the AVAudioSession is configured with, in case there was some parameter that was preventing audio output, to no avail - currently: var options = AVAudioSession.CategoryOptions() options.insert(.allowAirPlay) options.insert(.allowBluetooth) options.insert(.allowBluetoothA2DP) try session.setCategory(.playback, mode: .default, options: options) try? session.setPreferredIOBufferDuration(0.002) // ~96 samples at 44.1kHz try? session.setPrefersNoInterruptionsFromSystemAlerts(true) try? session.setPrefersInterruptionOnRouteDisconnect(false) try session.setActive(true, options: [.notifyOthersOnDeactivation]) All diagnostics within the app show the player operating correctly - files are played and flushed; AVAudioPlayerNodeCompletionCallbacks are called when they should be. But the output is not audible in the vehicle. I would much prefer to ship this app without full-blown CarPlay integration, but with working audio when connected via CarPlay, and work on full CarPlay integration for the next release. Is there some secret handshake I am just missing to make this work?
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245
Activity
Mar ’25
MusicKit API returns 500 Internal Server Error despite valid JWT and setup
My app is properly configured with MusicKit. I've generated a JWT using my valid credentials (Team ID, Key ID, private key), and I’ve ensured the time settings are correct via NTP. When I call: https://api.music.apple.com/v1/catalog/jp/search?term=ado&amp;types=songs I consistently receive a 500 Internal Server Error. The JWT is generated using ES256 with valid iat and exp values. I’ve confirmed the token decodes properly using jwt.io, and it's passed via the Authorization: Bearer header. Things I’ve confirmed: Key ID, Team ID, private key are correct App ID is configured with MusicKit capability JWT is generated and signed correctly macOS time is synced via NTP Used both curl and Python to test — same result Is there anything else I should check on the Apple Developer Console (like App ID, Certificates, or provisioning profile)? Or could this be a backend issue on Apple’s side? Any guidance would be appreciated.
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4
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497
Activity
Nov ’25