In the AVP project, a selector pops up, only wanting to filter spatial videos. When selecting the material of one of the spatial videos, the selection result returns empty. How can we obtain the video selected by the user and get the path and the URL of the file
The code is as follows:
PhotosPicker(selection: $selectedItem, matching: .videos) {
Text("Choose a spatial photo or video")
}
func loadTransferable(from imageSelection: PhotosPickerItem) -> Progress {
return imageSelection.loadTransferable(type: URL.self) { result in
DispatchQueue.main.async {
// guard imageSelection == self.imageSelection else { return }
print("加载成功的图片集合:(result)")
switch result {
case .success(let url?):
self.selectSpatialVideoURL = url
print("获取视频链接:(url)")
case .success(nil):
break
// Handle the success case with an empty value.
case .failure(let error):
print("spatial错误:(error)")
// Handle the failure case with the provided error.
}
}
}
}
Explore the integration of media technologies within your app. Discuss working with audio, video, camera, and other media functionalities.
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Activity
Hello,
I have been running into issues with setting nowPlayingInfo information, specifically updating information for CarPlay and the CPNowPlayingTemplate.
When I start playback for an item, I see lock screen information update as expected, along with the CarPlay now playing information.
However, the playing items are books with collections of tracks. When I select a new track(chapter) within the book, I set the MPMediaItemPropertyTitle to the new chapter name. This change is reflected correctly on the lock screen, but almost never appears correctly on the CarPlay CPNowPlayingTemplate. The previous chapter title remains set and never updates.
I see "Application exceeded audio metadata throttle limit." in the debug console fairly frequently.
From that a I figured that I need to minimize updates to the nowPlayingInfo dictionary. What I did:
I store the metadata dictionary in a local dictionary and only set values in the main nowPlayingInfo dictionary when they are different from the current value.
I kick off the nowPlayingInfo update via a task that initially sleeps for around 2 seconds (not a final value, just for my current testing). If a previous Task is active, it gets cancelled, so that only one update can happen within that time window.
Neither of these things have been sufficient. I can switch between different titles entirely and the information updates (including cover art).
But when I switch chapters within a title, the MPMediaItemPropertyTitle continues to get dropped. I know the value is getting set, because it updates on the lock screen correctly.
In total, I have 12 keys I update for info, though with the above changes, usually 2-4 of them actually get updated with high frequency.
I am running out of ideas to satisfy the throttling thresholds to accurately display metadata. I could use some advice.
Thanks.
Support external cameras in your iPadOS app and use Swift to read multiple camera feeds?
thanks
Hello,
Basically, I am reading and writing an asset.
To simplify, I am just reading the asset and rewriting it into an output video without any modifications.
However, I want to add a fade-out effect to the last three seconds of the output video.
I don’t know how to do this.
So far, before adding the CMSampleBuffer to the output video, I tried reducing its volume using an extension on CMSampleBuffer.
In the extension, I passed 0.4 for testing, aiming to reduce the video's overall volume by 60%.
My question is:
How can I directly adjust the volume of a CMSampleBuffer?
Here is the extension:
extension CMSampleBuffer {
func adjustVolume(by factor: Float) -> CMSampleBuffer? {
guard let blockBuffer = CMSampleBufferGetDataBuffer(self) else { return nil }
var length = 0
var dataPointer: UnsafeMutablePointer<Int8>?
guard CMBlockBufferGetDataPointer(blockBuffer, atOffset: 0, lengthAtOffsetOut: nil, totalLengthOut: &length, dataPointerOut: &dataPointer) == kCMBlockBufferNoErr else { return nil }
guard let dataPointer = dataPointer else { return nil }
let sampleCount = length / MemoryLayout<Int16>.size
dataPointer.withMemoryRebound(to: Int16.self, capacity: sampleCount) { pointer in
for i in 0..<sampleCount {
let sample = Float(pointer[i])
pointer[i] = Int16(sample * factor)
}
}
return self
}
}
Hi everyone,
I am currently on MacOS Tahoe (26.1), and for some weird reason my mac is not connecting via HDMI. To be accurate: it is connecting and the LG TV shows up in the Displays settings, but no image shows up in it, I have no idea why. This used to work as I've tried this cable before with the same exact tv. The cable is a basic Amazon Basics HDMI one.
Allow me just to advanced this question a little: usually terminal commands are more advanced recommendations, whereas basic questions like "have you connected it right" are just a waste of time
Topic:
Media Technologies
SubTopic:
Video
When setting the now playing info for playing media in MPNowPlayingInfoCenter we can set artwork. But it seems the Apple API for creating the artwork is crashing on iOS 18 (FB15145734).
On iOS 17 this gave the warning that the completion handler was not run on the main thread.
I've tried to seek help here: https://stackoverflow.com/questions/78989543/swift-data-race-with-appkit-mpmediaitemartwork-function/78990231?noredirect=1#comment139277425_78990231
but it seems that it's not possible to override the completion handler and therefor it's up to Apple to fix this issue.
.task {
await MainActor.run {
let nowPlayingInfoCenter = MPNowPlayingInfoCenter.default()
var nowPlayingInfo = [String: Any]()
let image = NSImage(named: "image")!
// warning: data race detected: @MainActor function at MPMediaItemArtwork/ContentView.swift:22 was not called on the main thread
nowPlayingInfo[MPMediaItemPropertyArtwork] = MPMediaItemArtwork(boundsSize: image.size, requestHandler: { _ in
// Not on main thread here!
return image
})
nowPlayingInfoCenter.nowPlayingInfo = nowPlayingInfo
}
}
I'm wondering if there is an alternative method to set the now playing artwork?
I was trying to set custom audio output device for a generated audio on macCatalyst.
While using let status = AudioUnitSetProperty(outputUnit,
kAudioOutputUnitProperty_CurrentDevice,
kAudioUnitScope_Global,
0,
&outputDeviceID,
UInt32(MemoryLayout.size))
kAudioOutputUnitProperty_CurrentDevice is invalid, and status = -10879, indicating an error.
STEPS TO REPRODUCE
Set Run Destination to MacOS and run the program. "AudioUnitSetProperty: 0" should be printed, indicating it works fine.
Set Run Destination to Mac Catalyst and run the program. "Error setting output device: -10879" should be printed, indicating an error.
Our streaming app uses FairPlay-protected video streams, which previously worked fine when using AVAssetResourceLoaderDelegate to provide CKCs.
Recently, we migrated to AVContentKeySession, and while everything works as expected during regular playback, we encountered an issue with AirPlay.
Our CKC has a 120-second expiry, so we renew it by calling renewExpiringResponseData..
This trigger the didProvideRenewingContentKeyRequest delegate and we respond with updated CKC.
However, when streaming via AirPlay, both video and audio freeze exactly after 120 seconds.
To validate the issue, I tested with AVAssetResourceLoaderDelegate and found that I can reproduce the same freeze if I do not renew the key. This suggests that AirPlay is not accepting the renewed CKC when using AVContentKeySession.
Additional Details:
This issue occurs across different iOS versions and various AirPlay devices.
The same content plays without issues when played directly on the device.
The renewal process is successful, and segments continue to load, but playback remains frozen.
Tried renewing the CKC bit early (100s).
I also tried setting player.usesExternalPlaybackWhileExternalScreenIsActive = true, but the issue persists.
We don't use persistentKey.
Is there anything else that needs to be considered for proper key renewal when AirPlaying?
Any help on how to fix this or confirmation if this is a known issue would be greatly appreciated.
Hi everyone,
After updating my Apple TV HD (model A1625) to tvOS 26, I’ve noticed a significant spike in CPU usage—up to 3× higher than before the update. Go from around 40% to 120%
Model: Apple TV HD (A1625)
tvOS Version: 26 (stable release) and beta version of 26.1,
App downgrade stream due to lack of cpu power
If anyone else is experiencing this, please share your findings or workarounds.
Would love to hear from Apple engineers or other developers if this is a known regression or if there’s a recommended fix.
Thanks!
Can i use iokit usb lib to disable build-in camera?
I noticed that AVSampleBufferDisplayLayerContentLayer is not released when the AVSampleBufferDisplayLayer is removed and released.
It is possible to reproduce the issue with the simple code:
import AVFoundation
import UIKit
class ViewController: UIViewController {
var displayBufferLayer: AVSampleBufferDisplayLayer?
override func viewDidLoad() {
super.viewDidLoad()
let displayBufferLayer = AVSampleBufferDisplayLayer()
displayBufferLayer.videoGravity = .resizeAspectFill
displayBufferLayer.frame = view.bounds
view.layer.insertSublayer(displayBufferLayer, at: 0)
self.displayBufferLayer = displayBufferLayer
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
self.displayBufferLayer?.flush()
self.displayBufferLayer?.removeFromSuperlayer()
self.displayBufferLayer = nil
}
}
}
In my real project I have mutliple AVSampleBufferDisplayLayer created and removed in different view controllers, this is problematic because the amount of leaked AVSampleBufferDisplayLayerContentLayer keeps increasing.
I wonder that maybe I should use a pool of AVSampleBufferDisplayLayer and reuse them, however I'm slightly afraid that this can also lead to strange bugs.
Edit: It doesn't cause leaks on iOS 18 device but leaks on iPad Pro, iOS 17.5.1
When building an application that can be built on iOS using macCatalyst, a link error like the one below will occur.
Undefined symbol: OBJC_CLASS$_AVPlayerViewController
The AVPlayerViewController documentation seems to support macCatalyst, but what is the reality?
[AVPlayerViewController](https://developer.apple.com/documentation/avkit/avplayerviewcontroller? language=objc)
Each version of the environment is as follows.
Xcode 16.2
macOS deployment target: macOS 10.15
iOS deployment target: iOS 13.0
Thank you for your support.
Topic:
Media Technologies
SubTopic:
General
We have developed a simple video player Swift application for macOS, which uses the AVFoundation Framework. A special feature of this app is the ability to play the video backward with speeds like -0.25x, -0.5x, and -1.0x. MP4 video file is played directly from the local file system, video codec is h.264, and audio AAC. Video files are huge, like 10 GB, and a length of 3 hours.
Playing video in reverse direction works well on a Macbook Air with M1 or M2 chip. When we run the same app with the same video on a Macbook Air with M3 chip the reverse playback is much worse. Playback might stutter badly, especially in the latter part of the video. This same behavior also happens in Apple's Quicktime video player when playing in the reverse direction with -1x speed. What's even more strange is that at one point of a time, the video playback is totally smooth, but again, after a while, the playback is stuttering. For example, this morning reverse playback worked 100 % smoothly, then I rebooted the Mac and tried again: the result was stuttering. After this the Mac stayed idle for several hours and I tried to reverse play video again: smooth performance! My conclusion: M3 playback works fine if the stars in the sky are aligned correctly. :-)
So it's not only our app, but also Quicktime player is having exactly the same behavior. And only with the M3 chip. The same symptom appears with another similar M3 Mac, so it can't be a single fault. At the same time, open-source video player iina can reverse play the video well on the same Mac.
All Macs have otherwise identical configuration: 16 GB RAM and macOS 15.1.1.
Have you experienced the same problem? Any chance to solve this problem?
I really hope that the M4 chip Mac is behaving better here.
We're integrating a web based group calling application within a native iOS application and finding that every time a CallKit session gets fully established the web based media streams break, rendering as gray with no audio.
Up to iOS 18 we worked around it by not fulfilling the call start action but that's no longer an option as the audio stopped getting automatically redirected to the speakers. We would now need the CXProvider's didActivateAudioSession callback but that would break the video.
The sample project loads up a simple webpage in a WKWebView which contains a video tag streaming the media from the device's camera.
At the same time it sets up a new CallKit session by requesting and fulfilling a CXStartCallAction transaction.
You will notice that the media doesn't render and, if you are to follow the warnings we left, you will find that not fulfilling the CXStartCallAction fixes it.
Unfortunately that's not a workaround we can use as we need the CXProvider delegate to inform us about audio session changes so we can redirect the audio to the speaker (so the proximity sensor doesn't activate and locking the screen doesn't end the call)
Any insights or workarounds would be greatly appreciated.
Hello,
Does anyone have a recipe on how to raycast VNFaceLandmarkRegion2D points obtained from a frame's capturedImage?
More specifically, how to construct the "from" parameter of the frame's raycastQuery from a VNFaceLandmarkRegion2D point?
Do the points need to be flipped vertically? Is there any other transformation that needs to be performed on the points prior to passing them to raycastQuery?
I am using AVMulti so the user captures two images how can I access those images if there is only one url that stores the captured images for the lockScreenCapture extension ? Plus how can I detect if the user opened the app from the extension to be able to navigate the user to the right screen ?
// Here addObserver for routeChangeNotification
func testAudioRoute() {
// My app is an VoIP app, so I need to set "playAndRecord" and "allowBluetooth"
try? AVAudioSession.sharedInstance().setCategory(.playAndRecord, options: [.duckOthers, .allowBluetooth, .allowBluetoothA2DP])
NotificationCenter.default.addObserver(self, selector: #selector(currentRouteChanged(noti:)), name: AVAudioSession.routeChangeNotification, object: nil)
}
// Print the "availableInputs" once got a notification
@objc func currentRouteChanged(noti: Notification) {
let availableInputs = AVAudioSession.sharedInstance().availableInputs?.compactMap({ $0.portType }) ?? []
let currentRouteInputs = AVAudioSession.sharedInstance().currentRoute.inputs.compactMap({ $0.portType })
let currentRouteOutputs = AVAudioSession.sharedInstance().currentRoute.outputs.compactMap({ $0.portType })
print("willtest: \navailableInputs=\(availableInputs), \ncurrentRouteInputs=\(currentRouteInputs), \ncurrentRouteOutputs=\(currentRouteOutputs)")
/*
When BT (Airpods pro 2) CONNECTTED: it will print like below when notification comes, this is correct.
----------------------------------------------------------
willtest:
availableInputs=[__C.AVAudioSessionPort(_rawValue: MicrophoneBuiltIn), __C.AVAudioSessionPort(_rawValue: BluetoothHFP)],
currentRouteInputs=[],
currentRouteOutputs=[__C.AVAudioSessionPort(_rawValue: BluetoothA2DPOutput)]
----------------------------------------------------------
When BT (Airpods pro 2) DISCONNECTTED: it will print like below when notification comes, this is wrong.
----------------------------------------------------------
availableInputs=[__C.AVAudioSessionPort(_rawValue: MicrophoneBuiltIn), __C.AVAudioSessionPort(_rawValue: BluetoothHFP)],
currentRouteInputs=[],
currentRouteOutputs=[__C.AVAudioSessionPort(_rawValue: Speaker)]
*/
}
So my question here is:
Why does the "availableInputs" still contain the "C.AVAudioSessionPort(_rawValue: BluetoothHFP)" item even though I have already disconnected the BT device? (Put AirPods in the case.)
BTW, if I tap the "Manual" button once I disconnected the BT, it also prints the "wrong" value for "availableInputs", and it will become normal after about 3~4 seconds.
I am trying to get access to raw audio samples from mic. I've written a simple example application that writes the values to a text file.
Below is my sample application. All the input samples from the buffers connected to the input tap is zero. What am I doing wrong?
I did add the Privacy - Microphone Usage Description key to my application target properties and I am allowing microphone access when the application launches. I do find it strange that I have to provide permission every time even though in Settings > Privacy, my application is listed as one of the applications allowed to access the microphone.
class AudioRecorder {
private let audioEngine = AVAudioEngine()
private var fileHandle: FileHandle?
func startRecording() {
let inputNode = audioEngine.inputNode
let audioFormat: AVAudioFormat
#if os(iOS)
let hardwareSampleRate = AVAudioSession.sharedInstance().sampleRate
audioFormat = AVAudioFormat(standardFormatWithSampleRate: hardwareSampleRate, channels: 1)!
#elseif os(macOS)
audioFormat = inputNode.inputFormat(forBus: 0) // Use input node's current format
#endif
setupTextFile()
inputNode.installTap(onBus: 0, bufferSize: 1024, format: audioFormat) { [weak self] buffer, _ in
self!.processAudioBuffer(buffer: buffer)
}
do {
try audioEngine.start()
print("Recording started with format: \(audioFormat)")
} catch {
print("Failed to start audio engine: \(error.localizedDescription)")
}
}
func stopRecording() {
audioEngine.stop()
audioEngine.inputNode.removeTap(onBus: 0)
print("Recording stopped.")
}
private func setupTextFile() {
let tempDir = FileManager.default.temporaryDirectory
let textFileURL = tempDir.appendingPathComponent("audioData.txt")
FileManager.default.createFile(atPath: textFileURL.path, contents: nil, attributes: nil)
fileHandle = try? FileHandle(forWritingTo: textFileURL)
}
private func processAudioBuffer(buffer: AVAudioPCMBuffer) {
guard let channelData = buffer.floatChannelData else { return }
let channelSamples = channelData[0]
let frameLength = Int(buffer.frameLength)
var textData = ""
var allZero = true
for i in 0..<frameLength {
let sample = channelSamples[i]
if sample != 0 {
allZero = false
}
textData += "\(sample)\n"
}
if allZero {
print("Got \(frameLength) worth of audio data on \(buffer.stride) channels. All data is zero.")
} else {
print("Got \(frameLength) worth of audio data on \(buffer.stride) channels.")
}
// Write to file
if let data = textData.data(using: .utf8) {
fileHandle!.write(data)
}
}
}
So experimenting with the new SpeechTranscriber, if I do:
let transcriber = SpeechTranscriber(
locale: locale,
transcriptionOptions: [],
reportingOptions: [.volatileResults],
attributeOptions: [.audioTimeRange]
)
only the final result has audio time ranges, not the volatile results.
Is this a performance consideration? If there is no performance problem, it would be nice to have the option to also get speech time ranges for volatile responses.
I'm not presenting the volatile text at all in the UI, I was just trying to keep statistics about the non-speech and the speech noise level, this way I can determine when the noise level falls under the noisefloor for a while.
The goal here was to finalize the recording automatically, when the noise level indicate that the user has finished speaking.
I am trying to use SpeechDetector Module in Speech framework along with SpeechTranscriber. and it is giving me an error
Cannot convert value of type 'SpeechDetector' to expected element type 'Array.ArrayLiteralElement' (aka 'any SpeechModule')
Below is how I am using it
let speechDetector = Speech.SpeechDetector()
let transcriber = SpeechTranscriber(locale: Locale.current,
transcriptionOptions: [],
reportingOptions: [.volatileResults],
attributeOptions: [.audioTimeRange])
speechAnalyzer = try SpeechAnalyzer(modules: [transcriber,speechDetector])