Hi
This is one of our top crashes. It does not contain any of our code in the stacktrace and we can't reproduce it. Those points make this crash very hard to understand and fix. We know that most of the crashes are happening on iPhone 13 with iOS 18.x.x. Also we see that a lot of cases happen when app goes into background (stacktrace contains -[UIApplication _applicationDidEnterBackground]).
2025-03-04_16-06-00.3670_-0500-6a273c7d5da97f098b5cc24898bb9761dc45208e.crash
2025-03-04_20-21-08.6609_-0500-2c08f640900f8a62c4f8a4f6f2a61feb052e66dd.crash
2025-03-04_20-46-27.7138_+0000-4d7ea89b1b564eda22ca63e708f7ad3909c7b768.crash
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 encountering a consistent crash in WebKit when using WKWebView to play a YouTube playlist in my iOS app. Playback starts successfully, but the web process terminates during the second video in the playlist. This only occurs on physical devices, not in the simulator.
Here’s a simplified Swift example of my setup:
import SwiftUI
import WebKit
struct ContentView: View {
private let playlistID = "PLig2mjpwQBZnghraUKGhCqc9eAy0UbpDN"
var body: some View {
YouTubeWebView(playlistID: playlistID)
.edgesIgnoringSafeArea(.all)
}
}
struct YouTubeWebView: UIViewRepresentable {
let playlistID: String
func makeUIView(context: Context) -> WKWebView {
let config = WKWebViewConfiguration()
config.allowsInlineMediaPlayback = true
let webView = WKWebView(frame: .zero, configuration: config)
webView.scrollView.isScrollEnabled = true
let html = """
<!doctype html>
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, maximum-scale=1.0">
<style>body,html{height:100%;margin:0;background:#000}iframe{width:100%;height:100%;border:0}</style>
</head>
<body>
<iframe
src="https://www.youtube-nocookie.com/embed/videoseries?list=\(playlistID)&controls=1&rel=0&playsinline=1&iv_load_policy=3"
frameborder="0"
allow="encrypted-media; picture-in-picture; fullscreen"
webkit-playsinline
allowfullscreen
></iframe>
</body>
</html>
"""
webView.loadHTMLString(html, baseURL: nil)
return webView
}
func updateUIView(_ uiView: WKWebView, context: Context) {}
}
#Preview {
ContentView()
}
Observed behavior:
First video plays without issue.
Web process crashes when the second video in the playlist starts.
Console logs show WebProcessProxy::didClose and repeated memory status messages.
Using ProcessAssertion or background activity does not prevent the crash.
Only occurs on physical devices; simulators do not reproduce the issue.
Questions:
Is there something I should change or add in my WKWebView setup or HTML/iframe to prevent the crash when playing the second video in a playlist on physical iOS devices?
Is there an officially supported way to limit memory or prevent WebKit from terminating the web process during multi-video playback?
Are there recommended patterns for playing YouTube playlists in a WKWebView on iOS without risking crashes?
Any tips for debugging or configuring WKWebView to make it more stable for continuous playlist playback?
Thanks in advance for any guidance!
Hi,
I am getting into a trap. Please check stack-trace, howto fix this?
regards, Joël
stack-trace with ExtAudioFileWrite
Hello, We have Video Stream app. It has HLS VOD Content. We supply 1080p, 4K Contents to users. Users were watching 1080p content before tvOS 26. Users can not watch 1080p content anymore when they update to tvOS 26. We have not changed anything at HLS playlist side and application version. This problem only occurs on Apple TV 4th Gen (A1625) tvOS 26 version. There is no problem with newer Apple TV devices. Would you help to resolve problem? Thanks in advance
Topic:
Media Technologies
SubTopic:
Streaming
Tags:
FairPlay Streaming
Apple TV
tvOS
HTTP Live Streaming
Hi everyone! I’ve been working with AVFoundation and trying to use the AVMetricEventStreamPublisher to discover media performance metrics, as described in the Apple documentation.
https://developer.apple.com/cn/videos/play/wwdc2024/10113/?time=508
However, when following the example code, I’m not getting the expected results. The performance metrics for both audio and video don’t seem to be captured properly.
Has anyone successfully used this example code? If so, could you share your experience or any solutions you’ve found? Any tips or insights would be greatly appreciated. Thanks in advance!
Ps. the example code:
AVPlayerItem *item = ...
AVMetricEventStream *eventStream = [AVMetricEventStream eventStream];
id subscriber = [[MyMetricSubscriber alloc] init];
[eventStream setSubscriber:subscriber queue:mySerialQueue]
[eventStream subscribeToMetricEvent:[AVMetricPlayerItemLikelyToKeepUpEvent class]];
[eventStream subscribeToMetricEvent:[AVMetricPlayerItemPlaybackSummaryEvent class]];
[eventStream addPublisher:item];
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?
I'm developing a photo backup app.
To detect newly added or edited photos since the app launched, I keep a local dictionary in the format [localIdentifier: modification_date].
However, PHAsset.modificationDate is not reliable.
It often changes unexpectedly, possibly due to system operations like iCloud metadata updates.
Is there a more reliable way to detect whether a photo has been modified by user since the last app launch?
I'm thinking about using content hash instead, but I'm not sure how heavy this operation is in terms of performance.
Hi! I am making an app for Apple Vision pro (VisionOS 2.5) that is scanning the surroundings and recognises all the texts around you. I tried to use the AVCaptureSession library, but when I run the app from xcode on the real AVP device, the camera is not accessible. I enabled the camera access in my Info.plist: NSCameraUsageDescription Used for live text recognition and I checked camera settings in the AVP, there are no restrictions. However I have always a black square with a crossed camera icon displayed instead of the image from the camera.
I tried a couple of different apps from Github using the AVCaptureSession and they all display the black square instead of the picture.
What can be wrong with the camera?
Topic:
Media Technologies
SubTopic:
Photos & Camera
I'm wondering if someone happened issues with currentPlaybackRate in released version of iOS 26.0?
There is no issue happened in case of iOS 18.5.
When I changed currentPlaybackRate on iOS 26.0, it seems to unexpectedly change currentPlaybackRate to be 0 or 1.0 forcibly no matter DRM or non-DRM contents. And also, playing music will be abnormal behavior and unstable with noise if currentPlaybackRate is not 1.0. And changes stop state and play state frequently.
FairPlay-Protected HLS Files Not Transferred via Quick Start I have an iOS app that downloads HLS files, which are protected by FairPlay. These files are stored locally, and their locations are managed using Core Data. When playing these tracks, I use AVURLAsset to access the stored file paths.
Recently, a client upgraded to a new iPhone and used Quick Start to transfer data from his old device. While all other app data was successfully transferred, including Core Data records and UserDefaults, the actual HLS files were missing. As a result, the app retained metadata about the downloaded content, but the files themselves were gone, causing playback failures.
Does Quick Start exclude certain types of locally stored files, especially DRM-protected HLS downloads, or is the issue related to how FairPlay-protected content is handled during the transfer of locally stored files?
Topic:
Media Technologies
SubTopic:
Streaming
Tags:
FairPlay Streaming
HTTP Live Streaming
AVFoundation
I have some tried-and-tested code that records and plays back audio via AUHAL which breaks on Tahoe on Intel. The same code works fine on Sequioa and also works on Tahoe on Apple Silicon.
To start with something simple, the following code to request access to the Microphone doesn't work as it should:
bool RequestMicrophoneAccess ()
{
__block AVAuthorizationStatus status =
[AVCaptureDevice authorizationStatusForMediaType: AVMediaTypeAudio];
if (status == AVAuthorizationStatusAuthorized)
return true;
__block bool done = false;
[AVCaptureDevice requestAccessForMediaType: AVMediaTypeAudio completionHandler: ^ (BOOL granted)
{
status = (granted) ? AVAuthorizationStatusAuthorized : AVAuthorizationStatusDenied;
done = true;
}];
while (!done)
CFRunLoopRunInMode (kCFRunLoopDefaultMode, 2.0, true);
return status == AVAuthorizationStatusAuthorized;
}
On Tahoe on Intel, the code runs to completion but granted is always returned as NO. Tellingly, the popup to ask the user to grant microphone access is never displayed, even though the app is not present in the Privacy pane and never appears there. On Apple Silicon, everything works fine.
There are some other problems, but I'm hoping they have a common underlying cause and that the Apple guys can figure out what's wrong from the information in this post. I'd be happy to test any potential fix. Thanks.
Topic:
Media Technologies
SubTopic:
Audio
I’m building a SwiftUI app whose primary job is to play audio. I manage all of the Now-Playing metadata and Command center manually via the available shared instances:
MPRemoteCommandCenter.shared()
MPNowPlayingInfoCenter.default().nowPlayingInfo
In certain parts of the app I also need to display videos, but as soon as I attach another AVPlayer, it automatically pushes its own metadata into the Control Center and overwrites my audio info.
What I need: a way to show video inline without ever having that video player update the system’s Now-Playing info (or Control Center).
In my app, I start by configuring the shared audio session
do {
try AVAudioSession.sharedInstance().setCategory(.playback,
mode: .default,
options: [
.allowAirPlay,
.allowBluetoothA2DP
])
try AVAudioSession.sharedInstance().setActive(true)
} catch {
NSLog("%@", "**** Failed to set up AVAudioSession \(error.localizedDescription)")
}
and then set the MPRemoteCommandCenter commands and MPNowPlayingInfoCenter nowPlayingInfo like mentioned above.
All this works without any issues as long as I only have one AVPlayer in my app. But when I add other AVPlayers to display some videos (and keep the main AVPlayer for the sound) they push undesired updates to MPNowPlayingInfoCenter:
struct VideoCardView: View {
@State private var player: AVPlayer
let videoName: String
init(player: AVPlayer = AVPlayer(), videoName: String) {
self.player = player
self.videoName = videoName
guard let path = Bundle.main.path(forResource: videoName, ofType: nil) else { return }
let url = URL(fileURLWithPath: path)
let item = AVPlayerItem(url: url)
self.player.replaceCurrentItem(with: item)
}
var body: some View {
VideoPlayer(player: player)
.aspectRatio(contentMode: .fill)
.onAppear {
player.isMuted = true
player.allowsExternalPlayback = false
player.actionAtItemEnd = .none
player.play()
MPNowPlayingInfoCenter.default().nowPlayingInfo = nil
MPNowPlayingInfoCenter.default().playbackState = .stopped
NotificationCenter.default.addObserver(forName: .AVPlayerItemDidPlayToEndTime,
object: player.currentItem,
queue: .main) { notification in
guard let finishedItem = notification.object as? AVPlayerItem,
finishedItem === player.currentItem else { return }
player.seek(to: .zero)
player.play()
}
}
.onDisappear {
player.pause()
}
}
}
Which is why I tried adding:
MPNowPlayingInfoCenter.default().nowPlayingInfo = nil
MPNowPlayingInfoCenter.default().playbackState = .stopped // or .interrupted, .unknown
But that didn't work.
I also tried making a wrapper around the AVPlayerViewController in order to set updatesNowPlayingInfoCenter to false, but that didn’t work either:
struct CustomAVPlayerView: UIViewControllerRepresentable {
let player: AVPlayer
func makeUIViewController(context: Context) -> AVPlayerViewController {
let vc = AVPlayerViewController()
vc.player = player
vc.updatesNowPlayingInfoCenter = false
vc.showsPlaybackControls = false
return vc
}
func updateUIViewController(_ controller: AVPlayerViewController, context: Context) {
controller.player = player
}
}
Hence any help on how to embed video in SwiftUI without its AVPlayer touching MPNowPlayingInfoCenter would be greatly appreciated.
All this was tested on an actual device with iOS 18.4.1, and built with Xcode 16.2 on macOS 15.5
I developed a driverkit extension based on overriding-the-default-usb-video-class-extension, but the link didn’t give the details of realization. I asked DTS who gave two tips:
1, Do you also have a CMIO extension to load in place of the default overriding-the-default-usb-video-class-extension
2, Your DriverKit extension’s info.plist is also missing the CameraAssistantBundleID.
I want to know why a driverkit extension needs a CMIO extension, what’s the data and control flow?
After upgrading to iOS 18.4, I'm no longer able to establish an AirPlay v1 connection to an audio system. The symptom is that the AirPlay route picker just spins when trying to connect to an audio system. It eventually gives up.
I tested this on an iPhone 14, connecting to a HomePod, AirPort express, AppleTV and a Wiim Pro. If I try connecting with AirPlay v2, ex: using Apple Music, the connection succeeds and audio can be played.
I'm the developer of an app that plays audio over AirPlay while also recording. My app has to use AirPlay v1 because AvAudioSession doesn't allow the policy .longFormAudio when the category is .playAndRecord. This issue is a real pain as it means my app is suddenly broken for many thousands of users.
Is anyone else seeing this issue? Any suggestions for a workaround?
My current app implements a custom video player, based on a AVSampleBufferRenderSynchronizer synchronising two renderers:
an AVSampleBufferDisplayLayer receiving decoded CVPixelBuffer-based video CMSampleBuffers,
and an AVSampleBufferAudioRenderer receiving decoded lpcm-based audio CMSampleBuffers.
The AVSampleBufferRenderSynchronizer is started when the first image (in presentation order) is decoded and enqueued, using avSynchronizer.setRate(_ rate: Float, time: CMTime), with rate = 1 and time the presentation timestamp of the first decoded image.
Presentation timestamps of video and audio sample buffers are consistent, and on most streams, the audio and video are correctly synchronized.
However on some network streams, on iOS, the audio and video aren't synchronized, with a time difference that seems to increase with time.
On the other hand, with the same player code and network streams on macOS, the synchronization always works fine.
This reminds me of something I've read, about cases where an AVSampleBufferRenderSynchronizer could not synchronize audio and video, causing them to run with independent and potentially drifting clocks, but I cannot find it again.
So, any help / hints on this sync problem will be greatly appreciated! :)
I'm developing an iOS app using AVFoundation for real-time video capture and object detection.
While implementing torch functionality with camera switching (between Wide and Ultra-Wide lenses), I encountered a critical issue where the camera freezes when toggling the torch while the Ultra-Wide camera is active.
Issue
If the torch is ON and I switch from Wide to Ultra-Wide, the camera freezes
If the Ultra-Wide camera is active and I try to turn the torch ON, the camera freezes
The iPhone Camera app allows using the torch while recording video with the Ultra-Wide lens, so this should be possible via AVFoundation as well.
Code snippet
DispatchQueue.global(qos: .userInitiated).async { [weak self] in
guard let self = self else { return }
let isSwitchingToUltraWide = !self.isUsingFisheyeCamera
let cameraType: AVCaptureDevice.DeviceType = isSwitchingToUltraWide ? .builtInUltraWideCamera : .builtInWideAngleCamera
let cameraName = isSwitchingToUltraWide ? "Ultra Wide" : "Wide"
guard let selectedCamera = AVCaptureDevice.default(cameraType, for: .video, position: .back) else {
DispatchQueue.main.async {
self.showAlert(title: "Camera Error", message: "\(cameraName) camera is not available on this device.")
}
return
}
do {
let currentInput = self.videoCapture.captureSession.inputs.first as? AVCaptureDeviceInput
self.videoCapture.captureSession.beginConfiguration()
if isSwitchingToUltraWide && self.isFlashlightOn {
self.forceEnableTorchThroughWide()
}
if let currentInput = currentInput {
self.videoCapture.captureSession.removeInput(currentInput)
}
let videoInput = try AVCaptureDeviceInput(device: selectedCamera)
self.videoCapture.captureSession.addInput(videoInput)
self.videoCapture.captureSession.commitConfiguration()
self.videoCapture.updateVideoOrientation()
DispatchQueue.main.async {
if let barButton = sender as? UIBarButtonItem {
barButton.title = isSwitchingToUltraWide ? "Wide" : "Ultra Wide"
barButton.tintColor = isSwitchingToUltraWide ? UIColor.systemGreen : UIColor.white
}
print("Switched to \(cameraName) camera.")
}
self.isUsingFisheyeCamera.toggle()
} catch {
DispatchQueue.main.async {
self.showAlert(title: "Camera Error", message: "Failed to switch to \(cameraName) camera: \(error.localizedDescription)")
}
}
}
}
Expected Behavior
Torch should be able to work when Ultra-Wide is active, just like the iPhone Camera app does.
The camera should not freeze when switching between Wide and Ultra-Wide with the torch ON.
AVCaptureSession should not crash when toggling the torch while Ultra-Wide is active.
Questions & Help Needed
Is this a known issue with AVFoundation?
How does the iPhone Camera app allow using the torch while recording in Ultra-Wide?
What’s the correct way to switch between Wide and Ultra-Wide cameras without freezing when the torch is active?
Info
Device tested: iPhone 13 Pro / iPhone 15 Pro / Iphone 15
iOS Version: iOS 17.3 / iOS 18.0
Xcode Version: 16.2
The same H265 encrypted Fairplay content can be played in all Apple devices except A1625.
The clear H265 content is played in A1625.
The question is: will this model (A1625) support H265 Fairplay encrypted content?
A ticket was created here:
https://discussions.apple.com/thread/255658006?sortBy=best
Topic:
Media Technologies
SubTopic:
Streaming
Tags:
FairPlay Streaming
Media
Video
HTTP Live Streaming
Hi everyone,
I’m running into an issue with PHPickerFilter when using PHPickerViewController.
When I configure the picker with a .videos and .livePhotos filter, it seems to work correctly in the Photos tab. However, when I switch to the Collections tab, the filter doesn’t always apply — users can still see and select static image assets in certain collections (e.g. from one of the People & Pets sections).
Here’s a simplified snippet of my setup:
var configuration = PHPickerConfiguration(photoLibrary: .shared())
configuration.selectionLimit = 1
var filters = [PHPickerFilter]()
filters.append(.videos)
filters.append(.livePhotos)
configuration.filter = PHPickerFilter.any(of: filters)
configuration.preferredAssetRepresentationMode = .current
let picker = PHPickerViewController(configuration: configuration)
picker.delegate = self
present(picker, animated: true)
Expected behavior:
The picker should consistently respect the filter across both Photos and Collections tabs, only showing assets that match the filter.
Actual behavior:
The filter seems to apply correctly in the Photos tab, but in the Collections tab, other asset types are still visible/selectable.
Has anyone else encountered this behavior? Is this expected or a known issue, or am I missing something in the configuration?
Thanks in advance!
Topic:
Media Technologies
SubTopic:
Photos & Camera
Tags:
Files and Storage
Media Library
Photos and Imaging
PhotoKit
Hi, when using ApplicationMusicPlayer from MusicKit my app automatically gets the media controls on the lock screen: Play/ Pause, Skip Buttons, Playback Position etc.
I would like to customize these. Tried a bunch of things, e.g. using MPRemoteCommandCenter. So far I haven't had any success.
Does anyone know how I can customize the media controls of ApplicationMusicPlayer.
Thank you.
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);
}