Hello everyone,
I'm looking for a definitive clarification on how to completely disable all video stabilization, including the hardware OIS, using AVFoundation. The goal is to achieve a completely raw, unstabilized video feed, which is crucial when using external equipment like gimbals to avoid conflicting stabilization motions.
My research points to using the AVCaptureConnection property preferredVideoStabilizationMode and setting it to AVCaptureVideoStabilizationMode.off.
The documentation for the .off case states:
A mode that doesn’t stabilize video capture.
This description is slightly ambiguous. It's unclear whether this only affects software-level stabilization (EIS, EIS+OIS, etc) or if it guarantees the complete deactivation of the physical OIS module. For professional video applications, this is a critical distinction.
So, I'd like to ask the community:
Has anyone been able to definitively confirm that setting preferredVideoStabilizationMode to .off also disables the hardware OIS? Are there any known tests or documentation that prove this behavior?
Is there an alternative or more direct method to ensure the OIS module is physically inactive during video capture?
What is the community's best practice for ensuring absolutely no stabilization is applied to the video pipeline?
Any insights or shared experiences on this topic would be greatly appreciated.
Thank you!
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I have a question regarding the behavior of AVAudioSession.sharedInstance().outputVolume.
Observed behavior:
When the app is in the foreground, I read audioSession.outputVolume (for example, 0.1).
The app is then moved to the background.
While the app is in the background, the user changes the system volume using the hardware buttons (for example, to 0.5).
When the app returns to the foreground, audioSession.outputVolume still reports the previous value (0.1).
From my testing, outputVolume only seems to update when the system volume is changed while the app is in the foreground. Volume changes made while the app is in the background are not reflected when the app returns to the foreground.
Questions:
According to Apple’s documentation for AVAudioSession.outputVolume:
“The systemwide output volume set by the user.”
https://developer.apple.com/documentation/avfaudio/avaudiosession/outputvolume
However, based on our testing on iOS 18.6.2 and iOS 18.1, the observed behavior seems to differ from this description.
Questions:
The documentation states that outputVolume represents the system-wide volume set by the user. In our testing, the value does not reflect volume changes made while the app is in the background and only updates when the app is in the foreground.Is this the expected behavior of AVAudioSession.outputVolume?
Is there any other recommended way in Swift to retrieve the current system volume that reflects user changes made both while the app is in the foreground and while it is in the background?
Any clarification on the intended behavior or recommended handling would be greatly appreciated.
(This only started happening as of Xcode 26.)
I know macOS and watchOS don't support this property, but all other platforms do (did?) up until I upgraded Xcode. Now when I compile I get this:
Value of type 'AVPlayerItem' has no member 'externalMetadata'
I'm working on a project to support spatial audio editing, using this sample project as a reference: https://developer.apple.com/documentation/Cinematic/editing-spatial-audio-with-an-audio-mix
This sample works well on an unedited capture, but does not work for a capture that has already been edited.
The failure is occurring at "let audioInfo = try await CNAssetSpatialAudioInfo(asset: myAsset)", which is throwing "no eligible audio tracks in asset".
I also find that for already edited captures, if i use CNAssetSpatialAudioInfo.assetContainsSpatialAudio, it returns false.
What i mean by "already edited" is that if I take a spatial capture with my iPhone 16, and then edit that capture in the Photos app using the Cinematic effect, and then save the edited output (e.g. edited_capture.mov), I can't import that edited_capture.mov into my project as a spatial audio asset.
Is this intentional behavior or a bug?
If it's intentional, can you describe why?
Topic:
Media Technologies
SubTopic:
Audio
I’m trying to build a playlist editor on macOS. I can create playlists via the Apple Music HTTP API, but DELETE always returns 401 even immediately after creation with
the same tokens.
Minimal repro:
#!/usr/bin/env bash
set -euo pipefail
BASE_URL="https://api.music.apple.com/v1"
PLAYLIST_NAME="${PLAYLIST_NAME:-blah}"
: "${APPLE_MUSIC_DEV_TOKEN:?}"
: "${APPLE_MUSIC_USER_TOKEN:?}"
create_body="$(mktemp)"
delete_body="$(mktemp)"
trap 'rm -f "$create_body" "$delete_body"' EXIT
curl -sS --compressed -o "$create_body" -w "Create status: %{http_code}\n" \
-X POST "${BASE_URL}/me/library/playlists" \
-H "Authorization: Bearer ${APPLE_MUSIC_DEV_TOKEN}" \
-H "Music-User-Token: ${APPLE_MUSIC_USER_TOKEN}" \
-H "Content-Type: application/json" \
-d "{\"attributes\":{\"name\":\"${PLAYLIST_NAME}\"}}"
playlist_id="$(python3 - "$create_body" <<'PY'
import json, sys
with open(sys.argv[1], "r", encoding="utf-8") as f:
data = json.load(f)
print(data["data"][0]["id"])
PY
)"
curl -sS --compressed -o "$delete_body" -w "Delete status: %{http_code}\n" \
-X DELETE "${BASE_URL}/me/library/playlists/${playlist_id}" \
-H "Authorization: Bearer ${APPLE_MUSIC_DEV_TOKEN}" \
-H "Music-User-Token: ${APPLE_MUSIC_USER_TOKEN}" \
-H "Content-Type: application/json"
I capture the response bodies like this:
cat "$create_body"
cat "$delete_body"
Result:
Create: 201
Delete: 401
I also checked the latest macOS SDK’s MusicKit interfaces and MusicLibrary.createPlaylist/edit/add(to:) are marked @available(macOS, unavailable), so I can’t create/
delete via MusicKit on macOS either.
Question: How can I implement a playlist editor on macOS (create/delete/modify) if:
MusicKit write APIs are unavailable on macOS, and
The HTTP API can create but DELETE returns 401?
Any guidance or official workaround would be hugely appreciated.
Hello,
I’m using a valid certificate bundle generated with SDK 26 (combined RSA‑1024 + RSA‑2048).
However, all my devices currently still generate SPC v2 during playback, including my iPhone 16 under iOS 26.2.
Apple staff mentioned that future iOS versions will send SPC v3 when using an SDK 26 certificate bundle.
Could you please clarify:
Which iOS/macOS versions will first support SPC v3?
Are there any additional client‑side requirements (Safari version, playback APIs, headers, etc.) to trigger SPC v3?
Is there any way to test SPC v3 today, e.g., using beta builds?
Thank you!
I’m using the shared instance of AVAudioSession. After activating it with .setActive(true), I observe the outputVolume, and it correctly reports the device’s volume.
However, after deactivating the session using .setActive(false), changing the volume, and then reactivating it again, the outputVolume returns the previous volume (before deactivation), not the current device volume. The correct volume is only reported after the user manually changes it again using physical buttons or Control Center, which triggers the observer.
What I need is a way to retrieve the actual current device volume immediately after reactivating the audio session, even on the second and subsequent activations.
Disabling and re-enabling the audio session is essential to how my application functions.
I’ve tested this behavior with my colleagues, and the issue is consistently reproducible on iOS 18.0.1, iOS 18.1, iOS 18.3, iOS 18.5 and iOS 18.6.2. On devices running iOS 17.6.1 and iOS 16.0.3, outputVolume correctly reflects the current volume immediately after calling .setActive(true) multiple times.
In iOS 26 (Developer Beta), the AVCaptureMetadataOutputObjectsDelegate no longer receives callbacks when metadataOutput.metadataObjectTypes = [.face] is set. On earlier iOS versions the issue does not occur. Interestingly, face detection works if I set the sessionPreset to .medium, but not with .high — except on the iPhone 16 Pro Max, where it works regardless.
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!
Is it possible to perform speech-to-text using AVAudioEngine to capture microphone input while being on a FaceTime call at the same time?
I tried implementing this, but whenever I attempt to start the AVAudioEngine while a FaceTime call is active, I get the following error:
“The operation couldn’t be completed. (OSStatus error 2003329396)”
I assume this might be due to microphone resource restrictions during FaceTime, but I’d like to confirm whether this limitation is at the system level or if there’s any possible workaround or entitlement that allows concurrent microphone access.
Has anyone encountered this issue or found a solution?
I'm creating Live Photos programmatically in my app using the Photos and AVFoundation frameworks. While the Live Photos work perfectly in the Photos app (long press shows motion), users cannot set them as motion wallpapers. The system shows "Motion not available" message.
Here's my approach for creating Live Photos:
// 1. Create video with required metadata
let writer = try AVAssetWriter(outputURL: videoURL, fileType: .mov)
let contentIdentifier = AVMutableMetadataItem()
contentIdentifier.identifier = .quickTimeMetadataContentIdentifier
contentIdentifier.value = assetIdentifier as NSString
writer.metadata = [contentIdentifier]
// Video settings: 882x1920, H.264, 30fps, 2 seconds
// Added still-image-time metadata at middle frame
// 2. Create HEIC image with asset identifier
var makerAppleDict: [String: Any] = [:]
makerAppleDict["17"] = assetIdentifier // Required key for Live Photo
metadata[kCGImagePropertyMakerAppleDictionary as String] = makerAppleDict
// 3. Generate Live Photo
PHLivePhoto.request(
withResourceFileURLs: [photoURL, videoURL],
placeholderImage: nil,
targetSize: .zero,
contentMode: .aspectFit
) { livePhoto, info in
// Success - Live Photo created
}
// 4. Save to Photos library
PHAssetCreationRequest.forAsset().addResource(with: .photo, fileURL: photoURL, options: nil)
PHAssetCreationRequest.forAsset().addResource(with: .pairedVideo, fileURL: videoURL, options: nil)
What I've Tried
Matching exact video specifications from Camera app (882x1920, H.264, 30fps)
Adding all documented metadata (content identifier, still-image-time)
Testing various video durations (1.5s, 2s, 3s)
Different image formats (HEIC, JPEG)
Comparing with exiftool against working Live Photos
Expected Behavior
Live Photos created programmatically should be eligible for motion wallpapers, just like those from the Camera app.
Actual Behavior
System shows "Motion not available" and only allows setting as static wallpaper.
Any insights or workarounds would be greatly appreciated. This is affecting our users who want to use their created content as wallpapers.
Questions
Are there additional undocumented requirements for Live Photos to be wallpaper-eligible?
Is this a deliberate restriction for third-party apps, or a bug?
Has anyone successfully created Live Photos that work as motion wallpapers?
Environment
iOS 17.0 - 18.1
Xcode 16.0
Tested on iPhone 16 Pro
Topic:
Media Technologies
SubTopic:
Photos & Camera
Tags:
LivePhotosKit JS
PhotoKit
Core Image
AVFoundation
Is there any way we can detect the status of the Show When Muted and Show on Skip Back device settings in code ?
Hi 👋! We have a SpriteKit-based app where we play AVAudio sounds in three different ways:
Effects (incl. UI sounds) with AVAudioPlayer.
Long looping tracks with AVAudioPlayer.
Short animation effects on the timeline of SpriteKit's SKScene files (effectively SKAudioNode nodes).
We've found that when you exit the app or otherwise interrupt audio plays, future audio plays often fail. For example, there's a WebKit-based video trailer inside the app, and if you play it, our looping background music track (2.) will stop playing, and won't resume as you close the trailer (return from WebKit). This is probably due to us not manually restarting the track (so may well be easily fixed). Periodically played AVAudioPlayer audio (1.) are not affected.
However, the more concerning thing is that the audio tracks on SKScene file timelines (3.) will no longer play. My hypothesis is that AVAudioEngine gets interrupted, and needs to be restarted for those AVAudioNode elements to regain functionality. Thing is, we don't deal with AVAudioEngine at all currently in the app, meaning it is never initiated to begin with.
Obviously things return to normal when you remove the app from short-term memory and restart it. However, it seems many of our users aren't doing this, and often report audio failing presumably due to some interruption in the past without the app ever being cleared from memory.
Any idea why timeline-run SKAudioNodes would fail like this? Should the app react to app backgrounding/foregrounding regarding audio?
Any help would be very much appreciated ✌️!
Description: I have identified a specific issue when recording acoustic guitar and other instruments on the iPhone 17 Pro Max using native applications (Voice Memos, Camera). The recordings contain an unnatural metallic resonance (ringing artifacts) that should not be present.
Testing and Methodology:
Hardware Verification: Initially, I suspected a hardware defect in the audio chip or microphone. However, extensive testing with third-party software suggests this is likely a software-level issue.
AudioShare Test: I conducted a test using the AudioShare app in "Measurement Mode" (which bypasses standard iOS system-wide audio processing). In this mode, the audio remains perfectly clean, and the metallic ringing disappears entirely.
Conclusion: The issue is rooted in the DSP (Digital Signal Processing) algorithms that iOS applies for noise suppression or voice enhancement. These algorithms appear to misinterpret the high-frequency overtones of acoustic instruments as background noise and attempt to "filter" them, resulting in audible digital artifacts.
Comparison Results: This issue has not been observed on devices from other brands or on older iPhone models (preliminary tests suggest older versions handle this better). Notably, the problem persists even in GarageBand, as the app still utilizes certain system-level processing layers.
Proposed Solution: I suggest adding a "Raw Audio" or "Instrument Mode" toggle within the Microphone/Audio settings for native apps. This mode should disable aggressive DSP processing, similar to how the AVAudioSession.Mode.measurement works in specialized apps.
Attachments: I am attaching 4 archives, including a final "Measurement Mode" folder with comparative samples (Measurement Mode vs. Standard Mode). The artifacts are most prominent when monitored through headphones.
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.
Hi there,
We're working on offline playback of DRM tracks. The persistent keys (also known as track licenses) for offline playback are stored locally on the device and are served from cache when a user initiates playback of a downloaded track.
Our persistent keys have a limited validity time and need to be refreshed when they expire. To prevent a situation where a persistent key expires while the user is offline, we've decided to eagerly refresh these keys one week before their expiration date. To make that happen we need to be able to obtain the expiration date of the given track license.
We've been attempting to use the makeSecureTokenForExpirationDateOfPersistableContentKey API to facilitate this process. The documentation states that this API returns a secret token representing the persistent key, which we can then exchange with our license server for the expiration date: https://developer.apple.com/documentation/avfoundation/avcontentkeysession/makesecuretokenforexpirationdate(ofpersistablecontentkey:completionhandler:)?language=objc
However, every time we call makeSecureTokenForExpirationDateOfPersistableContentKey, we receive an error with code -46250. We haven't been able to find any public references or documentation for this specific error code, which is preventing us from troubleshooting the issue. We are conducting our tests on a physical device, as the simulator does not support FairPlay playback. We don't use dual expiry approach.
Is our understanding of how to obtain the expiration timestamp correct? Are we using the makeSecureTokenForExpirationDateOfPersistableContentKey API as it was intended? What does the -46250 error code mean, and what steps should we take to fix our FairPlay implementation to make this work?
Thanks in advance for your assistance.
Hello,
My company has an in-store app with FPS SDK 4.x (1024) keys. We've handed those keys over to a trusted third-party and we do not have them. We've been in-store for several years.
The person that created the keys in our organization mistakenly stored them encrypted to our third-party's PGP keys, so we cannot decrypt them, and the third party also has no mechanism to provide us with the keys even though it is in their runtime environment. They only have secure mechanisms for us to upload keys onto their servers.
We are trying to migrate to a different third-party DRM provider, and would like to obtain new keys. Unfortunately, the developer portal won't let me create new keys, saying that we have exceeded the number of keys allowed, which I assume is one.
Additionally, the new DRM provider can only support SDK 4.x keys, and it appears that we can only request SDK 5.x keys on the Apple Developer portal, as the SDK 4.0 option is grayed out. Regardless, it seems that we are not able to request any keys.
We've submitted a request to the support e-mail address and received an automated e-mail that the response should take a few days, but may take longer on occasion. It's now been a month. The e-mail says that the reply address is not monitored. Is there any way we can accelerate this?
Thank you,
Carlos
Looking to implement to UI to tell the user to clean their lens in our app.
Implemented the KVO for the cameraLensSmudgeDetectionStatus but I'm having issues reliably triggering it in, both in our app and the main camera app. Tried to get inventive by putting tupperware over the lens, but I think the model driving this or the LiDAR sensor might be smart enough to detect there is something close to the lens.
Is there any way to trigger this change in a similar way we can trigger thermal changes in debug?
Thanks.
In my app I use AVAssetReaderTrackOutput to extract PCM audio from a user-provided video or audio file and display it as a waveform.
Recently a user reported that the waveform is not in sync with his video, and after receiving the video I noticed that the waveform is in fact double as long as the video duration, i.e. it shows the audio in slow-motion, so to speak.
Until now I was using
CMFormatDescription.audioStreamBasicDescription.mSampleRate
which for this particular user video returns 22'050. But in this case it seems that this value is wrong... because the audio file has two audio channels with different sample rates, as returned by
CMFormatDescription.audioFormatList.map({ $0.mASBD.mSampleRate })
The first channel has a sample rate of 44'100, the second one 22'050. If I use the first sample rate, the waveform is perfectly in sync with the video.
The problem is given by the fact that the ratio between the audio data length and the sample rate multiplied by the audio duration is 8, double the ratio for the first audio file (4). In the code below this ratio is given by
Double(length) / (sampleRate * asset.duration.seconds)
When commenting out the line with the sampleRate variable definition in the code below and uncommenting the following line, the ratios for both audio files are 4, which is the expected result. I would expect audioStreamBasicDescription to return the correct sample rate, i.e. the one used by AVAssetReaderTrackOutput, which (I think) somehow merges the stereo tracks. The documentation is sparse, and in particular it’s not documented whether the lower or higher sample rate is used; in this case, it seems like the higher one is used, but audioStreamBasicDescription for some reason returns the lower one.
Does anybody know why this is the case or how I should extract the sample rate of the produced PCM audio data? Should I always take the higher one?
I created FB19620455.
let openPanel = NSOpenPanel()
openPanel.allowedContentTypes = [.audiovisualContent]
openPanel.runModal()
let url = openPanel.urls[0]
let asset = AVURLAsset(url: url)
let assetTrack = asset.tracks(withMediaType: .audio)[0]
let assetReader = try! AVAssetReader(asset: asset)
let readerOutput = AVAssetReaderTrackOutput(track: assetTrack, outputSettings: [AVFormatIDKey: Int(kAudioFormatLinearPCM), AVLinearPCMBitDepthKey: 16, AVLinearPCMIsBigEndianKey: false, AVLinearPCMIsFloatKey: false, AVLinearPCMIsNonInterleaved: false])
readerOutput.alwaysCopiesSampleData = false
assetReader.add(readerOutput)
let formatDescriptions = assetTrack.formatDescriptions as! [CMFormatDescription]
let sampleRate = formatDescriptions[0].audioStreamBasicDescription!.mSampleRate
//let sampleRate = formatDescriptions[0].audioFormatList.map({ $0.mASBD.mSampleRate }).max()!
print(formatDescriptions[0].audioStreamBasicDescription!.mSampleRate)
print(formatDescriptions[0].audioFormatList.map({ $0.mASBD.mSampleRate }))
if !assetReader.startReading() {
preconditionFailure()
}
var length = 0
while assetReader.status == .reading {
guard let sampleBuffer = readerOutput.copyNextSampleBuffer(), let blockBuffer = sampleBuffer.dataBuffer else {
break
}
length += blockBuffer.dataLength
}
print(Double(length) / (sampleRate * asset.duration.seconds))
I am unable to find any clearcut documentation on configuring AVCaptureSession pipeline to capture video with proResRAW codec type, which is 16 bit format. Is it supported only with AVCaptureMovieFileOutput or one can have AVCaptureVideoDataOutput emitting 16-bit sample buffers that can be vended to AVAssetWriter?