Hello,
I am currently considering developing a Full Space app that enables a shared visionOS experience with nearby users.
Intended Features
A Mixed Full Space app in which dozens of 3D models are placed in the space.
These 3D models may play embedded animations when tapped, be programmatically moved or rotated, or be controlled via Reality Composer Pro timelines.
The app also includes audio, spatial audio, videos with audio, and videos without audio, which are rendered as VideoTextures on planes and played back in the space.
Some media elements play automatically, while others are triggered by user interaction.
However, it is unclear whether AVPlaybackCoordinator supports shared playback across multiple types of media, such as:
audio only
spatial audio
video without audio
video with audio
I am also unsure whether there are alternative or recommended approaches for synchronizing playback in this scenario.
Questions
Is it technically possible to implement the experience described above using visionOS?
Are there any important implementation considerations or limitations that should be taken into account?
For example, when two participants experience the app simultaneously, how is the content positioned for each participant?
Is the spatial placement of content shared across participants, or is it positioned relative to each participant’s viewpoint?
For nearby participants, is it necessary to register a spatial Persona? My understanding is that spatial Personas are not visible for nearby users during the experience; is this correct?
When experiencing SharePlay with nearby users, is it possible to share the experience without registering the other participant’s contact information?
I have watched the following session, but I was unable to fully understand the feasibility of the above use case or the concrete implementation details:
https://developer.apple.com/videos/play/wwdc2025/318/
Thank you.
AVFoundation
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Hi,
I understand that AVPlayer/AVFoundation doesn’t natively play MPEG-DASH manifests (.mpd) today, while HLS is supported and widely documented by Apple.
I’m not asking for roadmap commitments, but I’d like to understand whether there is any publicly documented rationale for not supporting DASH/MPD in AVFoundation (e.g., technical constraints, platform integration, DRM ecosystem, power/performance considerations, etc.).
Questions:
Is there any Apple statement / documentation explaining why DASH (MPD) isn’t supported in AVFoundation?
Is Apple’s recommended approach still “provide HLS for Apple clients” (potentially sharing CMAF segments and generating separate manifests)?
If there’s no public rationale, is filing Feedback Assistant the best channel for requesting MPD playback support?
Thanks!
Hello,
As far as I know and in all of my testing there is no way for a user or a developer to change the frame rate of the video output on iPadOS. If you connect an iPad via a USB Hub or a USB to HDMI Adaptor and then connect it to an external monitor it will output at 59.94fps.
I have a video app where a user monitors live video at 25fps and 30fps, they often output to an external display and there are times when the external display will stutter due to the mismatch in frame rate, ie. using 25fps and outputting at 59.94fps.
I thought it was impossible to change the video output frame rate, then in V3.1 of the Blackmagic Camera App I saw an interesting change in their release notes:
‘Support for HDMI Monitoring at Sensor Rate and Resolution’
This means there is some way to modify it, not sure if this is done via a Private API that Apple has allowed Blackmagic to use. If so, how can we access this or is there a way to enable this that is undocumented?
Thanks!
Hello, I am developing a custom player SDK using AVPlayer to support HLS and LL-HLS live streaming. I have some questions about the internal logic of AVPlayer regarding ABR, as this information is not explicitly covered in the documentation.
ABR Switching Logic: Does AVPlayer trigger bitrate switching primarily based on stall occurrences (buffer starvation)? I am curious if the switching logic is reactive to stalls or if it proactively switches to prevent them based on throughput estimation.
Developer Controls for ABR: To influence or control the ABR selection, are preferredPeakBitRate and preferredForwardBufferDuration the only properties available to developers? Are there any other recommended APIs to assist with ABR decisions?
Thank you for your help.
Hi everyone, does anybody have any resources I could check out regarding the 48->12mp binning behavior on supported sensors? I know the 48mp sensor on iPhone can automatically bin pixels for better low light performance. But not sure how to reliably make this happen in practice.
On iPhone 14 Pro+ with a 48MP sensor, I want the best of both worlds for ProRAW:
∙ Bright light: 48MP full resolution
∙ Low light: 12MP pixel-binned for better noise
`photoOutput.maxPhotoDimensions = CMVideoDimensions(width: 8064, height: 6048)
let settings = AVCapturePhotoSettings(rawPixelFormatType: proRawFormat, processedFormat: [...])
settings.photoQualityPrioritization = .quality
// NOT setting settings.maxPhotoDimensions — always get 12MP`
When I omit maxPhotoDimensions, iOS always returns 12MP regardless of lighting. When I set it to 48MP, I always get 48MP.
Is there an API to let iOS automatically choose the optimal resolution based on conditions, or should I detect low light myself (via device.iso / exposureDuration) and set maxPhotoDimensions accordingly?
Any help or direction would be much appreciated!
Hi everyone,
I'm developing a camera application that requires precise, predictable control over the focus system. I'm encountering unexpected behavior with face-driven autofocus in continuous autofocus mode.
Issue:
When using AVCaptureDevice.FocusMode.continuousAutoFocus, the system continues to prioritize faces for focus even after attempting to disable face-driven autofocus with:
device.automaticallyAdjustsFaceDrivenAutoFocusEnabled = false
device.isFaceDrivenAutoFocusEnabled = false
Observations:
The behavior is inconsistent across different scenes.
In well-lit/properly exposed scenes: focus persistently locks onto faces, ignoring my configuration.
.
In underexposed scenes: the intended focus behavior is more consistently respected.
Has anyone tried to make an ILPD based AIME file?
When I try the resulting AIME switches to USDZ Mesh instead of saving the ILPD Data.
I am developing an iOS camera app that can record video directly to external storage connected to an iPhone.
To detect whether an external USB storage device is connected and to obtain its URL, I am considering using AVExternalStorageDeviceDiscoverySession.
However, when checking support using AVExternalStorageDeviceDiscoverySession.isSupported, I observe that it returns true only on Pro model iPhones, and false on non-Pro models in my environment.
I have reviewed Apple’s official documentation, but I could not find any clear description of the supported devices or requirements (for example, whether this API is limited to Pro models or requires specific hardware capabilities).
I would appreciate any information regarding the following points:
①The actual requirements for AVExternalStorageDeviceDiscoverySession to be supported
Device limitations (Pro vs non-Pro models)
Hardware requirements (USB controller, external recording capability, etc.)
iOS version dependencies
②Whether support for non-Pro models is planned in the future
Tested environments
iPhone 16 Pro (iOS 18.7.1) → isSupported == true
iPhone 16e (iOS 26.2) → isSupported == false
iPhone 17 (iOS 26.2) → isSupported == false
iPhone Air (iOS 26.2) → isSupported == false
If anyone has observed similar behavior or has official information from Apple regarding this API, I would greatly appreciate your insights.
I am developing an iOS camera app that can record video directly to external storage connected to an iPhone.
To detect whether an external USB storage device is connected and to obtain its URL, I am considering using AVExternalStorageDeviceDiscoverySession.
However, when checking support using AVExternalStorageDeviceDiscoverySession.isSupported, I observe that it returns true only on Pro model iPhones, and false on non-Pro models in my environment.
I have reviewed Apple’s official documentation, but I could not find any clear description of the supported devices or requirements (for example, whether this API is limited to Pro models or requires specific hardware capabilities).
I would appreciate any information regarding the following points:
●The actual requirements for AVExternalStorageDeviceDiscoverySession to be supported
Device limitations (Pro vs non-Pro models)
Hardware requirements (USB controller, external recording capability, etc.)
iOS version dependencies
●Whether support for non-Pro models is planned in the future
Tested environments
iPhone 16 Pro (iOS 18.7.1) → isSupported == true
iPhone 16e (iOS 26.2) → isSupported == false
iPhone 17 (iOS 26.2) → isSupported == false
iPhone Air (iOS 26.2) → isSupported == false
If anyone has observed similar behavior or has official information from Apple regarding this API, I would greatly appreciate your insights.
I'm receiving output from avcapturesession and capturing an image using Vision, but the image is output in landscape orientation instead of portrait.
Even when I set the orientation to up in ciimage, cgimage, and uiimage, the image is still output in landscape orientation.
On iPhones 16 and below, the image is output in portrait orientation.
But on iPhones 17 and above, the image is output in landscape orientation.
Please help.
Hi everyone,
I'm running into an issue with AVAudioRecorder when handling interruptions such as phone calls or alarms.
Problem:
When the app is recording audio and an interruption occurs:
I handle the interruption with audioRecorder?.pause() inside AVAudioSession.interruptionNotification (on .began).
On .ended, I check for .shouldResume and call audioRecorder?.record() again.
The recorder resumes successfully, but only the audio recorded after the interruption is saved. The audio recorded before the interruption is lost, even though I'm using the same file URL and not recreating the recorder.
Repro:
Start a recording with AVAudioRecorder
Simulate a system interruption (e.g., incoming call)
Resume recording after the interruption
Stop and inspect the output audio file
Expected: Full audio (before and after interruption) should be saved.
Actual: Only the audio after interruption is saved; the earlier part is missing
Notes:
According to the documentation, calling .record() after .pause() should resume recording into the same file.
I confirmed that the file URL does not change, and I do not recreate the recorder instance.
No error is thrown by the system during this process.
This behavior happens consistently when the app is interrupted and resumed.
Question:
Is this a known issue? Is there a recommended workaround for preserving the full recording when interruptions happen?
Thanks in advance!
Facing an issue with audio playback using AVPlayerViewController in iOS application. We are using the native player to play recorded audio files.
When the AVPlayerViewController appears, the native user interface is displayed correctly, including the playback controls and the volume slider.
However, when the user interacts with the volume slider
The slider UI moves and responds to touch events.
The actual audio output volume does not change. The audio continues playing at the initial volume level regardless of the slider position.
We initialize the player and present it modally using the following code:
AVPlayerViewController *avController = [[AVPlayerViewController alloc] init];
avController.player = [AVPlayer playerWithURL:videoURL];
// Setting initial volume
avController.player.volume = 1.0f;
avController.modalPresentationStyle = UIModalPresentationOverFullScreen;
avController.allowsPictureInPicturePlayback = NO;
// Present the controller
[self presentViewController:avController animated:YES completion:nil];
I'm encountering errors while using AVAudioEngine with voice processing enabled (setVoiceProcessingEnabled(true)) in scenarios where the input and output audio devices are not the same. This issue arises specifically with mismatched devices, preventing the application from functioning as expected.
Works: Paired devices (e.g., MacBook Pro mic → MacBook Pro speakers) Fails: Mismatched devices (e.g., AirPods mic → MacBook Pro speakers)
When using paired input and output devices:
The setup works as expected. Example: MacBook Pro microphone → MacBook Pro speakers. When using mismatched devices:
AVAudioEngine setup fails during aggregate device construction. Example: AirPods microphone → MacBook Pro speakers. Error logs indicate a channel count mismatch.
Here are the partial logs. Due to the content limit, I cannot post the entire logs.
AUVPAggregate.cpp:1000 client-side input and output formats do not match (err=-10875)
AUVPAggregate.cpp:1036 err=-10875
AVAEInternal.h:109 [AVAudioEngineGraph.mm:1344:Initialize: (err = PerformCommand(*outputNode, kAUInitialize, NULL, 0)): error -10875
AggregateDevice.mm:329 Failed expectation of constructed aggregate (312): mInput.streamChannelCounts == inputStreamChannelCounts
AggregateDevice.mm:331 Failed expectation of constructed aggregate (312): mInput.totalChannelCount == std::accumulate(inputStreamChannelCounts.begin(), inputStreamChannelCounts.end(), 0U)
AggregateDevice.mm:182 error fetching default pair
AggregateDevice.mm:329 Failed expectation of constructed aggregate (336): mInput.streamChannelCounts == inputStreamChannelCounts
AggregateDevice.mm:331 Failed expectation of constructed aggregate (336): mInput.totalChannelCount == std::accumulate(inputStreamChannelCounts.begin(), inputStreamChannelCounts.end(), 0U)
AUHAL.cpp:1782 ca_verify_noerr: [AudioDeviceSetProperty(mDeviceID, NULL, 0, isInput, kAudioDevicePropertyIOProcStreamUsage, theSize, theStreamUsage), 560227702]
AudioHardware-mac-imp.cpp:3484 AudioDeviceSetProperty: no device with given ID
AUHAL.cpp:1782 ca_verify_noerr: [AudioDeviceSetProperty(mDeviceID, NULL, 0, isInput, kAudioDevicePropertyIOProcStreamUsage, theSize, theStreamUsage), 560227702]
AggregateDevice.mm:182 error fetching default pair
AggregateDevice.mm:329 Failed expectation of constructed aggregate (348): mInput.streamChannelCounts == inputStreamChannelCounts
AggregateDevice.mm:331 Failed expectation of constructed aggregate (348): mInput.totalChannelCount == std::accumulate(inputStreamChannelCounts.begin(), inputStreamChannelCounts.end(), 0U)
Is it possible to use voice processing with different input/output devices?
If yes, are there any specific configurations required to handle mismatched devices? How can we resolve channel count mismatch errors during aggregate device construction?
Are there settings or API adjustments to enforce compatibility between input/output devices? Are there any workarounds or alternative approaches to achieve voice processing functionality with mismatched devices?
For instance, can we force an intermediate channel configuration or downmix input/output formats?
I am new to Swift and iOS development, and I have a question about video capture performance.
Is it possible to capture video at a resolution of 4032×3024 while simultaneously running a vision/ML model on the video stream (e.g., using Vision or CoreML)?
I want to know:
whether iOS devices support capturing video at that resolution,
whether the frame rate drops significantly at that scale,
and whether it is practical to run a Vision/ML model in real-time while recording at such a high resolution.
If anyone has experience with high-resolution AVCaptureSession setups or combining them with real-time ML processing, I would really appreciate guidance or sample code.
Hello,
I am wondering if it is possible to have audio from my AirPods be sent to my speech to text service and at the same time have the built in mic audio input be sent to recording a video?
I ask because I want my users to be able to say "CAPTURE" and I start recording a video (with audio from the built in mic) and then when the user says "STOP" I stop the recording.
I develop a application with an uvc camera, this camera is a webcam, I use the AVFoundation library ,but when I run the code "[self.mCaptureSession startRunning]" ,I can not get the buffer, I already set the delegate, any answer will help.
My development team admin requested the Enterprise API for camera access on the vision pro. We got that granted, got a license for usage, and got instructions for integrating it with next steps.
We did the following:
Even when I try to download and run the sample project for "Accessing the Main Camera", and follow all the exact instructions mentioned here: https://developer.apple.com/documentation/visionos/accessing-the-main-camera
I am just unable to receive camera frames.
I added the capabilities, created a new provisioning profile with this access, added the entitlements to info.plist and entitlements, replaced the dummy license file with the one we were sent, and also have a matching bundle identifier and development certificate, but it is still not showing camera access for some reason.
"Main Camera Access" shows up in our Signing & Capabilities tab, and we also added the NSMainCameraDescription in the Info.plist and allow access while opening the app. None of this works. Not on my app, and not on the sample app that I just downloaded and tried to run on the Vision Pro after replacing the dummy license file.
Hello,
I've discovered a buffer initialization bug in AVAudioUnitSampler that happens when loading presets with multiple zones referencing different regions in the same audio file (monolith/concatenated samples approach).
Almost all zones output silence (i.e. zeros) at the beginning of playback instead of starting with actual audio data.
The Problem
Setup:
Single audio file (monolith) containing multiple concatenated samples
Multiple zones in an .aupreset, each with different sample start and sample end values pointing to different regions of the same file
All zones load successfully without errors
Expected Behavior:
All zones should play their respective audio regions immediately from the first sample.
Actual Behavior:
Last zone in the zone list: Works perfectly - plays audio immediately
All other zones: Output [0, 0, 0, 0, ..., _audio_data] instead of [real_audio_data]
The number of zeros varies from event to event for each zone. It can be a couple of samples (<30) up to several buffers.
After the initial zeros, the correct audio plays normally, so there is no shift in audio playback, just missing samples at the beginning.
Minimal Reproduction
1. Create Test Monolith Audio File
Create a single Wav file with 3 concatenated 1-second samples (44.1kHz):
Sample 1: frames 0-44099 (constant amplitude 0.3)
Sample 2: frames 44100-88199 (constant amplitude 0.6)
Sample 3: frames 88200-132299 (constant amplitude 0.9)
2. Create Test Preset
Create an .aupreset with 3 zones all referencing the same file:
Pseudo code
<Zone array>
<zone 1> start : 0, end: 44099, note: 60, waveform: ref_to_monolith.wav;
<zone 2> start sample: 44100, note: 62, end sample: 88199, waveform: ref_to_monolith.wav;
<zone 3> start sample: 88200, note: 64, end sample: 132299, waveform: ref_to_monolith.wav;
</Zone array>
3. Load and Test
// Load preset into AVAudioUnitSampler
let sampler = AVAudioUnitSampler()
try sampler.loadAudioFiles(from: presetURL)
// Play each zone (MIDI notes C4=60, D4=62, E4=64)
sampler.startNote(60, withVelocity: 64, onChannel: 0) // Zone 1
sampler.startNote(62, withVelocity: 64, onChannel: 0) // Zone 2
sampler.startNote(64, withVelocity: 64, onChannel: 0) // Zone 3
4. Observed Result
Zone 1 (C4): [0, 0, 0, ..., 0.3, 0.3, 0.3] ❌ Zeros at beginning
Zone 2 (D4): [0, 0, 0, ..., 0.6, 0.6, 0.6] ❌ Zeros at beginning
Zone 3 (E4): [0.9, 0.9, 0.9, ...] ✅ Works correctly (last zone)
What I've Extensively Tested
What DOES Work
Separate files per zone:
Each zone references its own individual audio file
All zones play correctly without zeros
Problem: Not viable for iOS apps with 500+ sample libraries due to file handle limitations
What DOESN'T Work (All Tested)
1. Different Audio Formats:
CAF (Float32 PCM, Int16 PCM, both interleaved and non-interleaved)
M4A (AAC compressed)
WAV (uncompressed)
SF2 (SoundFont2)
Bug persists across all formats
2. CAF Region Chunks:
Created CAF files with embedded region chunks defining zone boundaries
Set zones with no sampleStart/sampleEnd in preset (nil values)
AVAudioUnitSampler completely ignores CAF region metadata
Bug persists
3. Unique Waveform IDs:
Gave each zone a unique waveform ID (268435456, 268435457, 268435458)
Each ID has its own file reference entry (all pointing to same physical file)
Hypothesized this might trigger separate buffer initialization
Bug persists - no improvement
4. Different Sample Rates:
Tested: 44.1kHz, 48kHz, 96kHz
Bug occurs at all sample rates
5. Mono vs Stereo:
Bug occurs with both mono and stereo files
Environment
macOS: Sonoma 14.x (tested across multiple minor versions)
iOS: Tested on iOS 17.x with same results
Xcode: 16.x
Frameworks: AVFoundation, AudioToolbox
Reproducibility: 100% reproducible with setup described above
Impact & Use Case
This bug severely impacts professional music applications that need:
Small file sizes: Monolith files allow sharing compressed audio data (AAC/M4A)
iOS file handle limits: Opening 400+ individual sample files is not viable on iOS
Performance: Single file loading is much faster than hundreds of individual files
Standard industry practice: Monolith/concatenated samples are used by EXS24, Kontakt, and most professional samplers
Current Impact:
Cannot use monolith files with AVAudioUnitSampler on iOS
Forced to choose between: unusable audio (zeros at start) OR hitting iOS file limits
No viable workaround exists
Root Cause Hypothesis
The bug appears to be in AVAudioUnitSampler's internal buffer initialization when:
Multiple zones share the same source audio file
Each zone specifies different sampleStart/sampleEnd offsets
Key observation: The last zone in the zone array always works correctly.
This is NOT related to:
File permissions or security-scoped resources (separate files work fine)
Audio codec issues (happens with uncompressed PCM too)
Preset parsing (preset loads correctly, all zones are valid)
Questions
Is this a known issue? I couldn't find any documentation, bug reports, or discussions about this.
Is there ANY workaround that allows monolith files to work with AVAudioUnitSampler?
Alternative APIs? Is there a different API or approach for iOS that properly supports monolith sample files?
Hi,
I have an app that displays tens of short (<1mb) mp4 videos stored in a remote server in a vertical UICollectionView that has horizontally scrollable sections.
I'm caching all mp4 files on disk after downloading, and I also have a in-memory cache that holds a limited number (around 30) of players. The players I'm using are simple views that wrap an AVPlayerLayer and its AVPlayerItem, along with a few additional UI components.
The scrolling performance was good before iOS 26, but with the release of iOS 26, I noticed that there is significant stuttering during scrolling while creating players with a fileUrl. It happens even if use the same video file cached on disk for each cell for testing.
I also started getting this kind of log messages after the players are deinitialized:
<<<< PlayerRemoteXPC >>>> signalled err=-12785 at <>:1107
<<<< PlayerRemoteXPC >>>> signalled err=-12785 at <>:1095
<<<< PlayerRemoteXPC >>>> signalled err=-12785 at <>:1095
There's also another log message that I see occasionally, but I don't know what triggers it.
<< FigXPC >> signalled err=-16152 at <>:1683
Is there anyone else that experienced this kind of problem with the latest release?
Also, I'm wondering what's the best way to resolve the issue. I could increase the size of the memory cache to something large like 100, but I'm not sure if it is an acceptable solution because:
1- There will be 100 player instance in memory at all times.
2- There will still be stuttering during the initial loading of the videos from the web.
Any help is appreciated!
We are experiencing an issue related to DepthData from the TrueDepth camera on a specific device.
On December 1, we tested with the complainant’s device iPhone 14 / iOS 26.0.1, and observed that the depth image is received with empty values.
However, the same implementation works normally on iPhone 17 Pro Max (iOS 26.1) and iPhone 13 Pro Max (iOS 26.0.1), where depth data is delivered correctly.
In the problematic case:
TrueDepth camera is active
Face ID works normally
The app receives a DepthData object, but all values are empty (0), not nil
Because the DepthData object is not nil, this makes it difficult to detect the issue through software fallback handling.
We developed the feature with reference to the following Apple sample:
https://developer.apple.com/documentation/AVFoundation/streaming-depth-data-from-the-truedepth-camera
We would like to ask:
Are there known cases where Face ID functions normally but DepthData from the TrueDepth camera is returned as empty values?
If so, is there a recommended approach for identifying or handling this situation?
Any guidance from Apple engineers or the community would be greatly appreciated.
Thank you.