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
}
}
General
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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
Hello Apple,
i've been using ios for many years and never had any issues with urdu language keyboard, but since the new 18.4 beta update some words are not working correctly as it should like a name of my friend who's name is "راعنیہ" but the new updated version cannot type is together and keep seperating like "راعنی ہ" its so frustrating to use like that and its not just one but so many other words that it just cannot do properly also the new font and no gap concept its hurting my eyes so much while reading or even typing.. i hope apple fixes that asap..
thankyou
Hey, just wonderng if anyone knows whether the sdk for Android will be updated soon to support the new 16 KB memory page size requirement coming with Android 15?
Google’s going to require all apps targeting Android 15+ to support it starting November 2025
Has anyone heard anything from Apple or the SDK team about this?
Thanks!
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?
Topic:
Media Technologies
SubTopic:
General
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!
Topic:
Media Technologies
SubTopic:
General
Tags:
App Tracking Transparency
Media Player
iOS
MusicKit
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&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.
In iOS 26, AVSpeechSynthesizer read Mandarin into Cantonese pronunciation.
No matter how you set the language, and change the settings of my phone system, it doesn't work.
let utterance = AVSpeechUtterance(string: "你好啊")
//let voice = AVSpeechSynthesisVoice(language: "zh-CN") // not work
let voice = AVSpeechSynthesisVoice(language: "zh-Hans") // not work too
utterance.voice = voice
et synth = AVSpeechSynthesizer()
synth.speak(utterance)
Topic:
Media Technologies
SubTopic:
General
Tags:
Speech
Internationalization
Localization
AVFoundation
I am using Apple's original Lightning Digital AV-adapter (Lightning-to-HDMI dongle) to connect my iPhone to an external display via a HDMI cable.
I need to synchronize rendering with the external display's refresh rate, so I create a new CADisplayLink tied to the external display's UIScreen: UIScreen.screens[externalDisplayIdx].displayLink(withTarget:, selector:).
The callback is being called regularly, but with increasing delay relative to the CADisplayLink.timestamp, so the next time the callback is called, I have less and less time to draw the next frame (see the snippet below).
Assuming 60 FPS, the value of secondsTillDeadline starts at an arbitrary value in the range of approx -0.0001 to 0.0166667, and then it slowly decreases towards zero (and for a brief period it goes into small negative numbers). Once it reaches zero, it flips back to 0.0166667 and continues to decrease again. This cycle repeats indefinitely.
Changing the external display's resolution (UIScreen's mode) or the CADisplayLink's preferredFrameRateRange to a lower FPS does not seem to have any effect on the temporal drifting (even the rate of change seem to be the same).
When I create a new CADisplayLink for the iPhone's main screen, the value of secondsTillDeadline is stable, it does not drift and it is very close to 0.0166667, as expected.
Is this drift caused by the external monitor or by Apple's Lightning-to-HDMI dongle ...or is the problem somewhere else?
Can the drifting be stopped?
func onDisplayLinkUpdate(displayLink: CADisplayLink) {
// Gradually decreases from 0.01667 to -0.0001, then flips back to 0.01667 and continues to decrease
let secondsTillDeadline = displayLink.targetTimestamp - CACurrentMediaTime()
}
On an iPhone running iOS 26 beta 5, url(for: FilePath("subdir/asset.mov")) most always throws this error:
The URL for “subdir/asset.mov” couldn’t be retrieved: “asset.mov” couldn’t be copied to “subdir” because an item with the same name already exists.
Yet, contents(at: FilePath("subdir/asset.mov")) always returns Data for a playable AVMovie.
How can I avoid this url(for:) error?
The asset pack in question is downloaded. The error persists even after pack deletion, redownload, relaunch, and combinations of that.
// Assets repo root
subdir.aar
subdir/asset.mov
subdir/asset_thumb.heic
subdir/Manifest.json
// Manifest.json
{
"assetPackID": "subdir",
"downloadPolicy": {
"onDemand": {}
},
"fileSelectors": [
{
"directory": "subdir",
},
],
"platforms": [
"iOS",
"visionOS"
]
}
xcrun ba-package subdir/Manifest.json -o subdir.aar
xcrun ba-serve --host 192.168.0.10 -p 443 subdir.aar
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
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?
Add RPSystemBroadcastPickerView to the app,
After clicking, no method of SampleHandler is triggered
In SwiftUI there is a built-in component for displaying album artworks called Artwork but there is no equivalent for UIKit.
My current approach is to use the .url() method to read image's URL and download the image or read it from the disk but the performance is much worse than it was previously with MPMediaItem's artworkImage method.
let artworkQueue = DispatchQueue(
label: "MusicKit-ArtworkQueue",
qos: .default,
attributes: .concurrent
)
let artworkSemaphore = DispatchSemaphore(value: 5)
extension Song {
func artworkImage(for size: CGSize, completion: @escaping (UIImage?) -> Void) {
artworkQueue.async {
artworkSemaphore.wait()
defer {
artworkSemaphore.signal()
}
let imageURL = artwork?.url(
width: Int(size.width),
height: Int(size.height)
)
// I hate doing this as it might very well break in the future
guard let imageURL, imageURL.scheme == "musicKit"
else {
return completion(nil)
}
guard let imageData = try? Data(contentsOf: imageURL),
let image = UIImage(data: imageData) else {
return completion(nil)
}
completion(image)
}
}
}
I really dislike this approach because it feels hacky but somewhat works. You might ask what's the semaphore for? Well, without it I could notice that MusicKit was choking and after reading too many artworks at once.
Can someone from Apple please provide us with an example on how to use MusicKit with UIKit properly?
Ideally (IMO) we would have a method defined on Song and other MusicKit structures that returns the image for us, just like MPMediaItem had the .artwork() method. It would make our lives so much easier.
I am using MusicKit ApplicationMusicPlayer to play music in my app. Everything works fine as long as I'm not playing large playlists that contain hundreds of songs. When I to play collection of songs that is larger than around 300 I'm always getting the error message saying:
"Prepare to play failed" UserInfo={NSDebugDescription=Prepare to play failed, NSUnderlyingError=0x121d42dc0 {Error Domain=MPMusicPlayerControllerErrorDomain Code=9 "Remote call timed out" UserInfo={NSDebugDescription=Remote call timed out}}}))
It doesn't matter if songs are downloaded to the device or not.
I am aware that there is another initializer for player's queue that accepts Playlist instances but in my app users can choose to sort playlist tracks in different order than the default and that makes using that initializer not feasible for me.
I tried everything I could think of, I tried to fall back on MPMusicPlayerController and pass array of MPMusicPlayerPlayParameters to it but the result was the same.
typealias QueueEntry = ApplicationMusicPlayer.Queue.Entry
let player = ApplicationMusicPlayer.shared
let entries: [QueueEntry] = tracks
.compactMap {
guard let song = $0 as? Song else { return nil }
return QueueEntry(song)
}
Task(priority: .high) { [player] in
do {
player.queue = .init(entries, startingAt: nil)
try await player.play() // prepareToPlay failed
} catch {
print(error)
}
}
We use BassDSDPlayer / SFBAudioEngine to play just about any file, but playing Apple Music is failing. All subscriptions are up to date. We stop the SFBAudioEngine and the BassDSDPlayer before playing Apple Music to no avail.
PRINTS:
Supported files in /Users/dorian/Music/Music/Media.localized/Music/4: 28364
Apple Music is authorized and can play catalog.
Resetting default output device...
Releasing BassDSDPlayer audio device...
BassDSDPlayer: Audio device released.
STOPPED sfbAudioDevice
Default output device is ID: 76
applicationQueuePlayer _establishConnectionIfNeeded timeout [ping did not pong]
applicationQueuePlayer _establishConnectionIfNeeded timeout [ping did not pong]
Player State - After resetting output:
Playback Status: stopped
Queue Count: 0
No track is playing.
Music player reset successfully.
BassDSDPlayer: Audio device released.
Default output device set successfully: 76
Default output device is ID: 76
Default output device set successfully: 76
Default output device ID: 76
Validated PlayParameters for track: squabble up
PlayParameters: PlayParameters(id: 1781270321, kind: "song", isLibrary: nil, catalogID: nil, libraryID: nil, deviceLocalID: nil, rawValues: [:])
Starting playback...
Player State - After playback:
Playback Status: stopped
Queue Count: 1
No track is playing.
Notification BASS DSD NSConcreteNotification 0x600007ce2b00 {name = kUpdateSongInfo; object = {
AlbumTitle = GNX;
ArtistName = "Kendrick Lamar";
SongArtwork = "<NSImage 0x6000041b7ca0 Size={300, 300} RepProvider=<NSImageArrayRepProvider: 0x600003518770, reps:(\n "NSBitmapImageRep 0x600009ed9dc0 Size={300, 300} ColorSpace=(not yet loaded) BPS=8 BPP=(not yet loaded) Pixels=300x300 Alpha=NO Planar=NO Format=(not yet loaded) CurrentBacking=nil (faulting) CGImageSource=0x600007ce15c0"\n)>>";
SongLength = "157.992";
SongTitle = "squabble up";
Source = AppleMusic;
}}
Apple Music track loaded: squabble up by Kendrick Lamar
Player State - Before play:
Playback Status: stopped
Queue Count: 1
No track is playing.
prepareToPlay failed [no target descriptor]
NSError Code: 1, Domain: MPMusicPlayerControllerErrorDomain
Player State - After play:
Playback Status: stopped
Queue Count: 1
No track is playing.
func playAppleMusicTracks(tracks: [Track]) {
AppleMusicManager.shared.isAuthorizedAndReadyForPlayback { isAuthorized in
guard isAuthorized else {
print("Apple Music authorization or capabilities insufficient for playback.")
return
}
print("Resetting default output device...")
self.stopSFBAudioDevice()
self.resetMusicPlayer()
self.resetAudioSystem()
self.ensureOutputDeviceReady()
Task {
for track in tracks {
guard self.validatePlayParameters(for: track) else { continue }
do {
try await ApplicationMusicPlayer.shared.queue.insert(track, position: .afterCurrentEntry)
guard !ApplicationMusicPlayer.shared.queue.entries.isEmpty else {
print("Queue is empty after queuing. Playback cannot proceed.")
return
}
self.notifyAppleMusicTrackInfo(track)
} catch {
print("Error starting playback: \(error)")
if let nsError = error as NSError? {
print("NSError Code: \(nsError.code), Domain: \(nsError.domain)")
}
}
}
MusicKitWrapper.shared.logPlayerState(message: "After playback")
}
}
}
@objc public class MusicKitWrapper: NSObject {
@objc public static let shared = MusicKitWrapper()
private let player = ApplicationMusicPlayer.shared
// Play the current track
@objc public func play() {
guard !player.queue.entries.isEmpty else {
print("Queue is empty. Cannot start playback.")
return
}
logPlayerState(message: "Before play")
Task {
do {
try await player.prepareToPlay()
try await player.play()
print("Playback started successfully.")
} catch {
if let nsError = error as NSError? {
print("NSError Code: \(nsError.code), Domain: \(nsError.domain)")
}
}
logPlayerState(message: "After play")
}
}
Any help would be appreciated.
Thanks!
Hi All,
I am working on a DJ playout app (MACOS). The app has a few AVAudioPlayerNode's combined with the ApplicationMusicPlayer from Musickit. I can route the output of the AVaudioPlayer to a hardware device so that the audio files are directed to their own dedicated output on my Mac. The ApplicationMusicPlayer is following the default output and this is pretty annoying.
Has anyone found a solution to chain the ApplicationMusicPlayer and get it set to a output device?
Thanks
Pancras
Hi,
I am trying to enable the default MIDINetworkSession in a Catalyst app on MacOS like this:
MIDINetworkSession.default().isEnabled = true
MIDINetworkSession.default().connectionPolicy = .anyone
In the AppSandbox I have both incoming and outgoing network connections enabled. And I also added the NSLocalNetworkUsageDescription key to the info.plist. Bonjour services are also added to the info.plist:
NSBonjourServices
_apple-midi._udp.
Nevertheless the session stays disabled. Running the same code works just fine on iOS.
Is there any special setup I need to make on MacOS to enable the MIDINetworkSession?
Thanks!
I'm building a camera app that does some post processing after the photo has been taken. With 12MP the processing is pretty good, but larger images 24MP is very slow.
I created a very simple example to demonstrate the issue, which is loading an image and the rendering it to data.
let context = CIContext()
let imageUrl = Bundle.main.url(forResource: "12mp", withExtension: "jpg")!
let data = try! Data(contentsOf: imageUrl)
let ciImage = CIImage(data: data)!
let start = CFAbsoluteTimeGetCurrent()
let data = context.jpegRepresentation(of: ciImage, colorSpace: context.workingColorSpace!)
print(data?.count)
print("Resize Completed: " + String(CFAbsoluteTimeGetCurrent() - start))
Running this code on an iPhone 16 Pro with different images produces these benchmarks:
12MP => 0.03s
24MP => 1.22s
48MP => 2.98s
I understand that processing time will increase with resolution but it doesn't seem linear. I have tried setting different CiContext options such as .useSoftwareRenderer: false but it has made no difference.
From profiling the process it looks like the JPEG decoding is the bottle neck. This is for a 48MP Image:
Is there any way this can be improved?
I'm unable to play music using Musickit.js in the Chrome or Firefox browsers.
Even using the apple guide here: https://js-cdn.music.apple.com/musickit/v1/index.html - I've added my Music Developer Token and song/album url, but it only works in Safari and not in Chrome or Firefox.
I'm unsure if this is a global issue, or if there is something I need to do to enable playback in other browsers, but as it stands it's not working for me.
Thanks for any help in advance!