Hi, I'm working on an audio mixing app, that comes with bundled audio units that provide some of the app's core functionality. For the next release of that app, we are planning to make two changes: make the app sandboxed package the bundled audio units as .appex bundles instead as .component bundles, so we don't need to take care of the installation at the correct spot in the file system When trying this new approach, we run into problems where [[AVAudioUnitEffect alloc] initWithAudioComponentDescription:] crashes when trying to load our audio unit with the exception: AVAEInternal.h:109 [AUInterface.mm:468:AUInterfaceBaseV3: (AudioComponentInstanceNew(comp, &_auv2)): error -10863 Our audio unit has the `sandboxSafe flag enabled, and loads fine when the host app is not sandboxed, so I'm guessing I got the bundle id/code signing requirements for the .appex correct. It seems, that my .appex isn't even loaded, and the system rejects it because of its metadata. Maybe there something wrong the Info.plist generated by Juice? "BuildMachineOSBuild" => "23H222" "CFBundleDisplayName" => "elgato_sample_recorder" "CFBundleExecutable" => "ElgatoSampleRecorder" "CFBundleIdentifier" => "com.iwascoding.EffectLoader.samplerecorderAUv3" "CFBundleName" => "elgato_sample_recorder" "CFBundlePackageType" => "XPC!" "CFBundleShortVersionString" => "1.0.0.0" "CFBundleSignature" => "????" "CFBundleSupportedPlatforms" => [ 0 => "MacOSX" ] "CFBundleVersion" => "1.0.0.0" "DTCompiler" => "com.apple.compilers.llvm.clang.1_0" "DTPlatformBuild" => "24C94" "DTPlatformName" => "macosx" "DTPlatformVersion" => "15.2" "DTSDKBuild" => "24C94" "DTSDKName" => "macosx15.2" "DTXcode" => "1620" "DTXcodeBuild" => "16C5032a" "LSMinimumSystemVersion" => "10.13" "NSExtension" => { "NSExtensionAttributes" => { "AudioComponents" => [ 0 => { "description" => "Elgato Sample Recorder" "factoryFunction" => "elgato_sample_recorderAUFactoryAUv3" "manufacturer" => "Manu" "name" => "Elgato: Elgato Sample Recorder" "sandboxSafe" => 1 "subtype" => "Znyk" "tags" => [ 0 => "Effects" ] "type" => "aufx" "version" => 65536 } ] } "NSExtensionPointIdentifier" => "com.apple.AudioUnit-UI" "NSExtensionPrincipalClass" => "elgato_sample_recorderAUFactoryAUv3" } "NSHighResolutionCapable" => 1 } Any ideas what I am missing?

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. } } } }

Can anyone please guide me on how to use SFCustomLanguageModelData.CustomPronunciation? I am following the below example from WWDC23 https://wwdcnotes.com/documentation/wwdcnotes/wwdc23-10101-customize-ondevice-speech-recognition/ While using this kind of custom pronunciations we need X-SAMPA string of the specific word. There are tools available on the web to do the same Word to IPA: https://openl.io/ IPA to X-SAMPA: https://tools.lgm.cl/xsampa.html But these tools does not seem to produce the same kind of X-SAMPA strings used in demo, example - "Winawer" is converted to "w I n aU @r". While using any online tools it gives - "/wI"nA:w@r/".

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 have a Mac Catalyst video conferencing app that streams video using AVCaptureMultiCamSession. Everything has been working well for me in a variety of scenarios and hardware, but recently I got a report that virtual cameras / camera extensions do not seem to work - which I can reproduce 100% of the time by using something like OBS's virtual camera. FaceTime and Photo Booth work okay with these virtual cameras. Although my app can see and add the external AVCaptureDevice, I get an AVCaptureSessionRuntimeError posted when I start the session with a connection between the virtual camera and a AVCaptureVideoDataOutput (I don't get the error if I don't connect or add an output). The posted error is AVUnknown: AVCaptureSessionRuntimeErrorNotification with Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo={NSLocalizedFailureReason=An unknown error occurred (-12780), NSLocalizedDescription=The operation could not be completed, NSUnderlyingError=0x600001dcd680 {Error Domain=NSOSStatusErrorDomain Code=-12780 "(null)"}} Which doesn't tell me too much. I do see some fig assertions just above in Console though: <<<< BWMultiStreamCameraSourceNode >>>> Fig assert: "err == 0 " at bail (BWMultiStreamCameraSourceNode.m:3964) - (err=-12780) <<<< BWMultiStreamCameraSourceNode >>>> Fig assert: "err == 0 " at bail (BWMultiStreamCameraSourceNode.m:1591) - (err=-12780) <<<< BWMultiStreamCameraSourceNode >>>> Fig assert: "err == 0 " at bail (BWMultiStreamCameraSourceNode.m:1418) - (err=-12780) <<<< FigCaptureCameraSourcePipeline >>>> Fig assert: "err == 0 " at bail (FigCaptureCameraSourcePipeline.m:3572) - (err=-12780) <<<< FigCaptureCameraSourcePipeline >>>> Fig assert: "err == 0 " at bail (FigCaptureCameraSourcePipeline.m:4518) - (err=-12780) <<<< FigCaptureCameraSourcePipeline >>>> Fig assert: "err == 0 " at bail (FigCaptureCameraSourcePipeline.m:483) - (err=-12780) I've verified formats are sane (the usual 420v 1080p 30fps I have everywhere else) and data output functions and such, but I'm a bit stuck as to where to go from here. One thing that did stand out is that in the AVCamBarcode example I can see the virtual camera in that app's preview layer, but if I create an AVCaptureVideoDataOutput and add it to the session in that example, it fails in what looks like exactly the same way that my app does, with the same assertions. Does anyone have any advice? Thanks!

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 i use AVPlayer to obtain the video frame CVPixelBufferRef of an HDR video, and use AVSampleBufferDisplayLayer to display it on the screen, after a period of time, the HDR video content and screen gradually darken, losing the HDR effect. Steps to reproduce: Create an AVPlayer to loop an HDR video, specify the video frame format as kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange Create a timer to get the video frame CVPixelBufferRef at 30 frames per second Use AVSampleBufferDisplayLayer to display CVPixelBufferRef on the screen Don't operate the phone, wait for a period of time (such as 40 minutes), the HDR effect disappears and the screen darkens Note: You need to use an iPhone device, iOS 18.5 and below operating system You need to ensure that the HDR video is played in a loop, that is, to ensure that the screen continues to display HDR content, wait for a period of time, depending on different devices, you need to wait for 20-40 minutes. In the iPhone Photos app,the same problem will occur after playing HDR video in a loop for a long time Expected Results: When rendering HDR content for a long time, it is guaranteed that there is always an HDR effect, and the HDR content and screen will not be darkened. Current Results: After about 20-40 minutes, the HDR effect disappears and the screen darkens.

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.

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 have application using PTT Framework to record audio messages when app is backgrounded. Right now we are using AVAudioRecorder for that purpose. And problem is one specific user has frequent issue - recorded audio contains only silence. I've checked almost everything I can imagine but didn't find any possible reason of issue. Conditions: AVAudioRecorder uses following configuration: [ AVEncoderAudioQualityKey: AVAudioQuality.low.rawValue, AVFormatIDKey : kAudioFormatMPEG4AAC, AVNumberOfChannelsKey: 1, AVSampleRateKey: 16000.0 ] App waits both didBeginTransmitting and didActivate audioSession from PTChannelManager (audio session has playback category at that moment) App does AVAudioSession category change to playAndRecord App gets routeChangeNotification with categoryChange and category = playAndRecord There is no any interruption notifications from AVAudioSession during recording There is no any error notification from AVAudioRecorder Any idea what exactly I do wrong? Is there anything else I should check? Thanks in advance. P.S. it looks like recording audio with AudioUnit has the same issue, but let's exclude it from question atm for simplicity.

I am looking to learn more about the new Capture Button controls for iPhone 16, and am working to adapt the AVCam Sample Code to support the Capture Button. While I believe I've followed the guidance in the Enhancing your app experience with the Camera Control documentation, I'm finding that while my AVCaptureControl items seem to be added to the capture session, the Capture Button does not ever do anything, nor are any of the delegate methods called. After I configure my capture session per the setupSession() method, I'm calling a method I added, func configureCameraControls(device:AVCaptureDevice): func configureCameraControls(device: AVCaptureDevice) { guard captureSession.supportsControls else { assertionFailure("App does not support camera control.") return } // Set the controls delegate captureSession.setControlsDelegate(controlsDelegate, queue: sessionQueue) // Begin configuring the capture session. captureSession.beginConfiguration() // Remove previously configured controls, if any. for control in captureSession.controls { captureSession.removeControl(control) } // Add a zoom control let systemZoomSlider = AVCaptureSystemZoomSlider(device: device) { zoomFactor in // TODO } // Create a control to adjust the device's exposure bias. let systemBiasSlider = AVCaptureSystemExposureBiasSlider(device: device) // Add a custom slider let focusSlider = AVCaptureSlider("Focus", symbolName: "scope", in: 0...1) focusSlider.setActionQueue(sessionQueue) { focusValue in // TODO } // Iterate over the passed in controls. for control in [systemZoomSlider, systemBiasSlider, focusSlider] { // Add the control to the capture session if possible. if captureSession.canAddControl(control) { captureSession.addControl(control) } else { print("Unable to add control \(control).") } } // Commit the capture session configuration. captureSession.commitConfiguration() } I define the controls delegate like so: final class CaptureControlsDelegate: NSObject, AVCaptureSessionControlsDelegate { func sessionControlsDidBecomeActive(_ session: AVCaptureSession) { } func sessionControlsWillEnterFullscreenAppearance(_ session: AVCaptureSession) { } func sessionControlsWillExitFullscreenAppearance(_ session: AVCaptureSession) { } func sessionControlsDidBecomeInactive(_ session: AVCaptureSession) { } } Which I instantiate earlier on in my app's lifecycle and make available to the CaptureService actor. I'm not sure if this snippet can provide enough detail to gather some help, but I can't quite fathom why the camera/capture pipeline works, but I'm not getting any functionality from the Capture Button nor is the AVCaptureSessionControlsDelegate ever having its methods called.

We are using the MediaPlayer API to provide CarPlay support. Starting in iOS 18 we are having issues updating the content list. The initial list of items will populate on a fresh instance but soon there after an error will show up saying we are not entitled to "com.apple.mediaremote.external-artwork-validation". From that point onwards no changes we make to our MPPlayableContentDataSource are reflected in CarPlay. Even after restarting the device. While the MediaPlayer API is marked as deprecated, we are still using it to provide CarPlay support going back to iOS 10. Has anyone else run into this or have suggestions for workarounds?

I tried adding watermarks to the recorded video. Appending sample buffers using AVAssetWriterInput's append method fails and when I inspect the AVAssetWriter's error property, I get the following: Error Domain=AVFoundation Error Domain Code=-11800 "This operation cannot be completed" UserInfo={NSLocalizedFailureReason=An unknown error occurred (-12780), NSLocalizedDDescription=This operation cannot be completed, NSUnderlyingError=0x302399a70 {Error Domain=NSOSStatusErrorDomain Code=-12780 "(null)"}} As far as I can tell -11800 indicates an AVErrorUknown, however I have not been able to find information about the -12780 error code, which as far as I can tell is undocumented. Thanks! Here is the code

Hello everyone, I am using QRCodeScanner library in my project, the scan qr code was working in earlier ipad os but now in iPad os 18 it's stopped working.

Hi, I have just implemented an Audio Unit v3 host. AgsAudioUnitPlugin *audio_unit_plugin; AVAudioUnitComponentManager *audio_unit_component_manager; NSArray<AVAudioUnitComponent *> *av_component_arr; AudioComponentDescription description; guint i, i_stop; if(!AGS_AUDIO_UNIT_MANAGER(audio_unit_manager)){ return; } audio_unit_component_manager = [AVAudioUnitComponentManager sharedAudioUnitComponentManager]; /* effects */ description = (AudioComponentDescription) {0,}; description.componentType = kAudioUnitType_Effect; av_component_arr = [audio_unit_component_manager componentsMatchingDescription:description]; i_stop = [av_component_arr count]; for(i = 0; i < i_stop; i++){ ags_audio_unit_manager_load_component(audio_unit_manager, (gpointer) av_component_arr[i]); } /* instruments */ description = (AudioComponentDescription) {0,}; description.componentType = kAudioUnitType_MusicDevice; av_component_arr = [audio_unit_component_manager componentsMatchingDescription:description]; i_stop = [av_component_arr count]; for(i = 0; i < i_stop; i++){ ags_audio_unit_manager_load_component(audio_unit_manager, (gpointer) av_component_arr[i]); } But this doesn't show me Audio Unit v2 plugins, why? regards, Joël

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() }

I have an HDR10+ encoded video that if loaded as a mov plays back on the Apple Vision Pro but when that video is encoded using the latest (1.23b) Apple HLS tools to generate an fMP4 - the resulting m3u8 cannot be played back in the Apple Vision Pro and I only get back a "Cannot Open" error. To generate the m3u8, I'm just calling mediafilesegmenter (with -iso-fragmented) and then variantplaylistcreator. This completes with no errors but the m3u8 will playback on the Mac using VLC but not on the Apple Vision Pro. The relevant part of the m3u8 is: #EXT-X-STREAM-INF:AVERAGE-BANDWIDTH=40022507,BANDWIDTH=48883974,VIDEO-RANGE=PQ,CODECS="ec-3,hvc1.1.60000000.L180.B0",RESOLUTION=4096x4096,FRAME-RATE=24.000,CLOSED-CAPTIONS=NONE,AUDIO="audio1",REQ-VIDEO-LAYOUT="CH-STEREO" {{url}} Has anyone been able to use the HLS tools to generate fMP4s of MV-HEVC videos with HDR10?

It's simple to reproduce. The bug is simply when you queue a bunch of songs to play, it will always queue less than what you gave it. Here, I'm attempting to play an apple curated playlist, it will only queue a subset, usually less than 15, but as low as 1 out of 100. Use the system's forward and backwards to test it out. Here is the code, just paste it in to the ContentView file and make sure you have the capibility to run it. import SwiftUI import MusicKit struct ContentView: View { var body: some View { VStack{ Button("Play Music") { Task{ await playMusic() } } } } } func getOnlySongsFromTracks(tracks:MusicItemCollection<Track>?) async throws ->MusicItemCollection<Song>?{ var songs:[Song]? if let t = tracks{ songs = [Song]() for track in t { if case let .song(song) = track { songs?.append(song) print("track is song \(track.debugDescription)") }else{ print("track not song \(track.debugDescription)") } } } if let songs = songs { let topSongs = MusicItemCollection(songs) return topSongs } return nil } func playMusic() async { // Request authorization let status = await MusicAuthorization.request() guard status == .authorized else { print("Music authorization denied.") return } do { // Perform a hardcoded search for a playlist let searchTerm = "2000" let request = MusicCatalogSearchRequest(term: searchTerm, types: [Playlist.self]) let response = try await request.response() guard let playlist = response.playlists.first else { print("No playlists found for the search term '\(searchTerm)'.") return } // Fetch the songs in the playlist let detailedPlaylist = try await playlist.with([.tracks]) guard let songCollection = try await getOnlySongsFromTracks(tracks: detailedPlaylist.tracks) else { print("no songs found") return } guard let t = detailedPlaylist.tracks else { print("no tracks") return } // Create a queue and play let musicPlayer = ApplicationMusicPlayer.shared let q = ApplicationMusicPlayer.Queue(for: t) musicPlayer.queue = q try await musicPlayer.play() print("Now playing playlist: \(playlist.name)") } catch { print("An error occurred: \(error.localizedDescription)") } }

I’ve tried both AVCaptureVideoDataOutputSampleBufferDelegate (captureOutput) and AVCaptureDataOutputSynchronizerDelegate (dataOutputSynchronizer), but the number of depth frames and saved timestamps is significantly lower than the number of frames in the .mp4 file written by AVAssetWriter. In my code, I save: Timestamps for each frame to a metadata file Depth frames to a binary file Video to an .mp4 file If I record a 4-second video at 30fps, the .mp4 file correctly plays for 4 seconds, but the number of stored timestamps and depth frames is much lower—around 70 frames instead of the expected 120. Does anyone know why this mismatch happens? func dataOutputSynchronizer(_ synchronizer: AVCaptureDataOutputSynchronizer, didOutput synchronizedDataCollection: AVCaptureSynchronizedDataCollection) { // Read all outputs guard let syncedDepthData: AVCaptureSynchronizedDepthData = synchronizedDataCollection.synchronizedData(for: depthDataOutput) as? AVCaptureSynchronizedDepthData, let syncedVideoData: AVCaptureSynchronizedSampleBufferData = synchronizedDataCollection.synchronizedData(for: videoDataOutput) as? AVCaptureSynchronizedSampleBufferData else { // only work on synced pairs return } if syncedDepthData.depthDataWasDropped || syncedVideoData.sampleBufferWasDropped { return } let depthData = syncedDepthData.depthData let depthPixelBuffer = depthData.depthDataMap let sampleBuffer = syncedVideoData.sampleBuffer guard let videoPixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer), let formatDescription = CMSampleBufferGetFormatDescription(sampleBuffer) else { return } addToPreviewStream?(CIImage(cvPixelBuffer: videoPixelBuffer)) if !canWrite() { return } // Extract the presentation timestamp (PTS) from the sample buffer let timestamp = CMSampleBufferGetPresentationTimeStamp(sampleBuffer) //sessionAtSourceTime is the first buffer we will write to the file if self.sessionAtSourceTime == nil { //Make sure we don't start recording until the buffer reaches the correct time (buffer is always behind, this will fix the difference in time) guard sampleBuffer.presentationTimeStamp >= self.recordFromTime! else { return } self.sessionAtSourceTime = sampleBuffer.presentationTimeStamp self.videoWriter!.startSession(atSourceTime: sampleBuffer.presentationTimeStamp) } if self.videoWriterInput!.isReadyForMoreMediaData { self.videoWriterInput!.append(sampleBuffer) self.videoTimestamps.append( Timestamp( frame: videoTimestamps.count, value: timestamp.value, timescale: timestamp.timescale ) ) let ddm = depthData.depthDataMap depthCapture.addDepthData(pixelBuffer: ddm, timestamp: timestamp) } }

Dear Sirs, I've written an audio driver based on IOUserAudioDevice. In my IOOperationHandler I can receive and send the audio samples as expected. Is there any way to configure the number of samples transferred in each call? Currently it seem to be around 512 samples per call, which relates to 10.7 millisecs when operating on 48 kHz samplerate. I'd like to achieve something like 48 or 96 samples per call. I did some experiments and tried calls to SetOutputLatency() etc. but so far I didn't find the right way to change the in_io_buffer_frame_size in the callback. I'd like to do this as smaller buffer sizes would allow lower latencies for the subsequent audio processing. Thanks and best regards, Johannes