I am working on an app which plays audio - https://youtu.be/VbAfUk_eYl0?si=nJg5ayy2faWE78-g - and one of the features is, on restart, if you had paused playback of a file at the time the app was previously shut down (or were playing one at the time of shutdown), the paused state and position in the file is restored exactly as it was, on restart.
The functionality works. However, it seems impossible to get the "now playing" information in iOS into the right state to reflect that via the MediaPlayer API. On restart, handlers are attached to the play/pause/togglePlayPause actions on MPRemoteCommandCenter.shared(), and the map of media info is updated on MPNowPlayingInfoCenter.default().nowPlayingInfo.
What happens is that iOS's media view shows the audio as playing and offers a pause button - even though the play action is enabled and the pause action is disabled.
Once playback has been initiated (my workaround is to have the pause action toggle the play state, since otherwise you wouldn't be able to initiate playback from controls in a car without initiating it once from a device first).
I've created a simplified white-noise-player demo to illustrate the problem - simply build and deploy it, and then start the app, lock your device and look at the playback controls on the lock screen. It will show a pause button - same behavior I've described.
https://github.com/timboudreau/ios-play-pause-demo
I've tried a few things to narrow down the source of the issue - for example, thinking that not MPNowPlayingInfoPropertyPlaybackProgress and MPMediaItemPropertyPlaybackDuration might be the culprit (since the system interpolates elapsed time and it's recommended to update those properties infrequently) on startup might do the trick, but the result is the same, just without a duration or progress shown.
What governs this behavior, and is there some way to explicitly tell the media player API your current state is paused?
Explore the integration of media technologies within your app. Discuss working with audio, video, camera, and other media functionalities.
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I found that when the development tool above Xcode16 ran my app, I opened the suspended inscription function, and then opened the system camera, the content in the suspended window would not be displayed, and the suspended window would have a black screen. However, this phenomenon does not appear on Xcode15.4 development tools, it is the same code, I do not know why
Topic:
Media Technologies
SubTopic:
Photos & Camera
Tags:
Swift Packages
App Clips
Developer Tools
iOS
I was advised to post here by a Code-Level Support representative. Below will be a copy of my initial issue report, and my minimally reproductive test project can be found at the following GitHub repository URL...
https://github.com/PierceLBrooks/vtUudSeiNalCmake
DESCRIPTION OF PROBLEM
When encoding H264 video codec data using the VTCompressionSession API facilities available through the VideoToolbox framework on MacOS, the resultant bitstream will invariably include Unregistered User Data SEI NAL units that carry the UUID "47564adc-5c4c-433f-94ef-c5113cd143a8".
The proprietary decoders we are working with currently struggle with filtering out these NAL units.
Can you explain what purpose this serves, what the meaning of the byte-wise unit payloads are, and which configuration settings the VideoToolbox encoder instance specifically depends upon for triggering the insertion of them?
STEPS TO REPRODUCE
1. Invoke the instantiation of a new VideoToolbox H264 encoder object by calling VTCompressionSessionCreate with appropriate configuration flags.
2. Push frames through the encoder, receiving their encoded byte buffer counterparts through an asynchronous callback.
3. Write that encoded data to some buffer which will contain the totality of the encoder's output.
4. Inspect the NAL units of the initial portion of this output bitstream buffer.
5. Observe the presence of at least one Unregistered User Data SEI NAL unit carrying the "47564adc-5c4c-433f-94ef-c5113cd143a8" UUID near the beginning of the output segment.
I’m building a professional camera app where users can customize the video recording format and color grading. In the func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) method, I handle video frames and use Metal for real-time color grading. This works well when device.activeColorSpace is sRGB or P3, and the results are great. However, when the color space is HLG_BT2020 or appleLog, the MTKTextureLoader.newTexture(cgImage: cgImage, options: options) method throws an error. After researching, I found that the video frame in these color spaces has a bit-per-channel (bpc) greater than 8 after being converted to CGImage, causing the texture creation to fail. I tried converting the CGImage to a lower bpc to successfully create the texture, but the final output image is garbled and not as expected. Is there a solution to this issue?
My app Balletrax is a music player for people to use while they teach ballet. Used to be you could silence notifications during use, but now the customer seems to have to know how to use Focus mode, remember to turn it on and off, and have to check the notifications one does and doesn't want to use. Is there no way to silence all notifications when the app is in use?
Hi!
I am writing a browser extension that allows you to control the playback of media content on a music service website. Unfortunately Safari does not support tracking changes to the audible property in an event tabs.onUpdated. Is there an alternative to this event? I'm looking for a way to track when the automatic inference engine interrupts playback on a music service website.
That you.
Has anyone been able to successfully use MusicCatalogSearchRequest in a playgrounds app?
I have configured my playground similar to a regular app: app id with automatic music token generation turned on, music access authorized within the app itself, but whenever I query MusicCatalogSearchRequest I get an error thrown with .developerTokenRequestFailed.
Considering musickit is restricted in the sim, it would not surprise me if it was the same in playgrounds but it would be super helpful if I could prototype with musickit in playgrounds 4!
We are currently working on a CarPlay navigation app and so far everything is working well except for speaking turn notifications.
Our TTS implementation works fine on the phone and works fine on CarPlay if the voice is spoken over the speaker in the car. If users connect a BT headset to the car and listen through that headset, then the voice commands are chopped up / stutter.
Why would users use BT headset? Well, we are working on a motorcycle app, and there are no speakers usually on a motorcycle.
It sounds like the BT channel is opened and closed repeatedly for every character / word spoken. This happens on different CarPlay devices and different Bluetooth headsets, we have reports from multiple users that they find this behavior annoying and that other apps work fine.
Is this a known issue? Are there possible workaround?
We are encountering an issue where AVPlayer throws the error:
Error Domain=AVFoundationErrorDomain Code=-11819 "Cannot Complete Action" > Underlying Error Domain[(null)]:Code[0]:Desc[(null)]
This error seems to occur intermittently during video playback, especially after extended usage or when switching between different streams. We observe Error 11819 (AVFoundationErrorDomain) in Conviva platform that some of our users experience it but we couldn't reproduce it so far and we’re need support to determine the root cause and/or best practices to prevent it.
Some questions we have:
What typically triggers this error?
Could it be related to memory/resource constraints, network instability, or backgrounding?
Are there any recommended ways to handle or recover from this error gracefully?
Any insights or guidance would be greatly appreciated. Thanks!
Topic:
Media Technologies
SubTopic:
Streaming
I'm getting this error when I launch my application on the iPhone 14 Pro via Xcode. Everything builds OK. I"m using the audio kit plugin and Sound Pipe Audiokit.
The error starts as soon as I start the app and will carry on repeatedly.
I have background processing turned on as I'd like the sounds to play when the phone is locked via the headphones.
I can't find anything online about this error. None of my catches are printing anything in the logs either. So I don't know if this is just something that pops up repeatedly or whether there is something fundamentally wrong.
private func setupAudioSession() {
do {
let session = AVAudioSession.sharedInstance()
try session.setCategory(.playback, mode: .default, options: [.mixWithOthers])
try session.setActive(true, options: .notifyOthersOnDeactivation)
} catch {
errorMessage = "Failed to set up audio session: (error.localizedDescription)"
print(errorMessage ?? "")
}
}
// MARK: - Background Task Handling
private func setupBackgroundTaskHandling() {
// Handle app entering background
notificationObservers.append(
NotificationCenter.default.addObserver(
forName: UIApplication.didEnterBackgroundNotification,
object: nil,
queue: .main,
using: { [weak self] _ in
// Safely unwrap self
guard let self = self else { return }
self.handleBackgroundTransition()
}
)
)
I'm not sure if this is the code causing the issue. Any help would be gratefully appreciated. This is my first app I'm working on .
Topic:
Media Technologies
SubTopic:
Audio
Environment→ ・Device: iPad 10th generation ・OS:**iOS18.3.2
I'm using AVAudioSession to record sound in my application. But I recently came to realize that when the app starts a recording session on a tablet, OS automatically sets the tablet volume to 50% and when after recording ends, it doesn't change back to the previous volume level before starting the recording. So I would like to know whether this is an OS default behavior or a bug?
If it's a default behavior, I much appreciate if I can get a link to the documentation.
I need to implement a solution through an API or custom driver to completely block out the built-in speakers and microphone of Mac, because I need other apps to use specified external devices as audio input and output. Is there a way to achieve this requirement? What I mean is that even in system preferences, it should not be possible to choose the built-in microphone and speakers; only my external device can be used.
When I play an m3u8 video using AVPlayer, it can play smoothly at 2x speed. However, when I set it to 3x speed, the playback is not smooth and there is no sound.
Topic:
Media Technologies
SubTopic:
Video
Hey everyone,
I'm encountering an issue with audio sample rate conversion that I'm hoping someone can help with. Here's the breakdown:
Issue Description:
I've installed a tap on an input device to convert audio to an optimal sample rate.
There's a converter node added on top of this setup.
The problem arises when joining Zoom or FaceTime calls—the converter gets deallocated from memory, causing the program to crash.
Symptoms:
The converter node is being deallocated during video calls.
The program crashes entirely when this happens.
Traditional methods of monitoring sample rate changes (tracking nominal or actual sample rates) aren't working as expected.
The Big Challenge:
I can't figure out how to properly monitor sample rate changes.
Listeners set up to track these changes don't trigger when the device joins a Zoom or FaceTime call.
Please, if anyone has experience with this or knows a solution, I'd really appreciate your help. Thanks in advance!
When I use musicKit SDK for Android 1.1.2, I found that MediaContainerType only defines three types:
NONE = 0;
ALBUM = 1;
PLAYLIST = 2;
The RADIO_STATION type is not defined.
However, the documentation of com.apple.android.music.playback.model states that the RADIO_STATION type is supported.
This problem causes an error after I pass in the stations ID:
MediaSessionManager com.apple.android.music.sdk.testapp D onPlaybackError() Quincy java.io.IOException
May I ask how to solve this problem?
Hello Apple Developer Community,
I am trying to play an HLS stream using the React Native Video player (underneath it's using AvPlayer). I am able to play the stream smoothly, but in some cases the player can not play the stream properly.
Behaviour:
react-native-video: I am getting the below error.
Error details from react-native-video player:
Error Code: -12971
Domain: CoreMediaErrorDomain
Localised Description: The operation couldn’t be completed. (CoreMediaErrorDomain error -12971.)
Target: 2457
The error does not provide a specific failure reason or recovery suggestion, which makes troubleshooting challenging.
AvPlayer on native iOS project: Video playback stopped after playing a few seconds.
AVPlayer configuration:
player.currentItem?.preferredForwardBufferDuration = 1
player.automaticallyWaitsToMinimizeStalling = true
N.B.: The same buffer duration is working perfectly for others.
Stream properties:
video resolution: 1280 x 720
I have attached an overview report generated from MediaStreamValidator.
I would appreciate any insights or suggestions on how to address this error. Has anyone in the community experienced a similar issue or have any advice on potential solutions?
Thank you for your help!
Hello! I have been following the UsingAVFoundationToPlayAndPersistHTTPLiveStreams sample code in order to test persisting streams to disk. In addition to support for m3u8, I have noticed in testing that this also seems to work for MP3 Audio, simply by changing the plist entries to point to remote URLs with audio/mpeg content. Is this expected, or are there caveats that I should be aware of?
Thanks you!
I am working on a project for macOS where I am taking an AVCaptureSession's CVPixelBuffer and I need to convert it into a MTLTexture for rendering. On macOS the pixel format is 2vuy, there does not seem to be a clear format conversion while converting to a metal texture. I have been able to convert it to a texture but the color space seems to be off as it is rendering distorted colors with a double image.
I believe 2vuy is a single pane color space and I have tried to account for that, but I am unaware of what is off.
I have attached The CVPixelBuffer and The distorted MTLTexture along with a laundry list of errors.
On iOS my conversions are fine, it is only the macOS 2vuy pixel format that seems to have issues.
My code for the conversion is also attached.
If there are any suggestions or guidance on how to properly convert a 2vuy CVPixelBuffer to a MTLTexture I would greatly appreciate it.
Many Thanks
Conversion_Logs.txt
ConversionCode.swift
I use the Apple Music API to poll my listening history at regular intervals.
Every morning between 5:30AM and 7:30AM, I observe a strange pattern in the API responses. During this window, one or more of the regular polling intervals returns a response that differs significantly from the prior history response, even though I had no listening activity at that time.
I'm using this endpoint: https://api.music.apple.com/v1/me/recent/played/tracks?types=songs,library-songs&include[library-songs]=catalog&include[songs]=albums,artists
Here’s a concrete example from this morning:
Time: 5:45AM
Fetch 1 Tracks (subset):
1799261990, 1739657416, 1786317143, 1784288789, 1743250261, 1738681804, 1789325498, 1743036755, ...
Time: 5:50AM
Fetch 2 Tracks (subset):
1799261990, 1739657416, 1786317143, 1623924746, 1635185172, 1574004238, 1198763630, 1621299055, ...
Time: 5:55AM
Fetch 3 Tracks (subset):
1799261990, 1739657416, 1786317143, 1784288789, 1743250261, 1738681804, 1789325498, 1743036755, ...
At 5:50, a materially different history is returned, then it returns back to the prior history at the next poll. I've listened to all of the tracks in each set, but the 5:50 history drops some tracks and returns some from further back in history.
I've connected other accounts and the behavior is consistent and repeatable every day across them. It appears the API is temporarily returning a different (possibly outdated or cached?) view of the user's history during that early morning window.
Has anyone seen this behavior before?
Is this a known issue with the Apple Music API or MusicKit backend? I'd love any insights into what might cause this, or recommendations on how to work around it.
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! :)