Explore the integration of media technologies within your app. Discuss working with audio, video, camera, and other media functionalities.

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AVAudioEngine Stop Method
Hi all! I have been experiencing some issues when using the AVAudioEngine to play audio and record input while doing a voice chat (through the PTT Interface). I noticed if I connect any players to the AudioGraph OR call start that the audio session becomes active (this is on iOS). I don't see anything in the docs or the header files in the AVFoundation, but is it possible that calling the stop method on an engine deactivates the audio session too? In a normal app this behavior seems logical, but when using PTT all activation and deactivation of the audio session must go through the framework and its delegate methods. The issue I am debugging is that when the engine with the input node tapped gets stopped, and there is a gap between the input and when the server replies with inbound audio to be played and something seems to be getting the hardware/audio session into a jammed state. Thanks for any feedback and/or confirmation on this behavior!
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Jan ’25
Unable to Capture 24MP Photos
Hello, I'm wondering how to capture 24MP photos. I'm currently testing on an iPhone 16 Pro Max. By default, the device's activeFormat supports 24MP (photo dimensions: {4032x3024, 5712x4284}). For the photoOutput, I'm setting the maxPhotoDimensions to videoDevice.activeFormat.supportedMaxPhotoDimensions.lastObject, and setting MaxPhotoQualityPrioritization to quality. When capturing, I'm applying the same maxPhotoDimensions and photoQualityPrioritization settings from the photoOutput directly to the AVCapturePhotoSettings. What could be the issue? // Objective-C // setup [self.photoOutput setMaxPhotoQualityPrioritization:AVCapturePhotoQualityPrioritizationQuality]; CMVideoDimensions maxPhotoDimensions = [(NSValue *)videoDevice.activeFormat.supportedMaxPhotoDimensions.lastObject CMVideoDimensionsValue]; [self.photoOutput setMaxPhotoDimensions:maxPhotoDimensions]; // capturing AVCapturePhotoSettings *photoSettings = [AVCapturePhotoSettings photoSettings]; photoSettings.maxPhotoDimensions = self.photoOutput.maxPhotoDimensions; photoSettings.photoQualityPrioritization = self.photoOutput.maxPhotoQualityPrioritization; [self.photoOutput capturePhotoWithSettings:photoSettings delegate:photoCaptureDelegate]; ...
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591
Jan ’25
Camera USB
am new to using Swift for a Mac Application. I am trying to control an external UVC-compliant camera focus and other capabilities. However, I'm having trouble with this and don't know where to start. I have downloaded an application from the App Store and it can control the focus and other capabilities. I've tried IOKit but this seems to be complicated and this does not return any capabilities or control the camera. I also tried AVfoundation and was able to open the camera, but using the following code did not work for me. as a device.isFocusPointOfInterestSupported returns false and without checking the app crashes. @IBAction func focusChanged(_ sender: NSSlider) { do { guard let device = videoDevice else { return } try device.lockForConfiguration() // Check if focus mode and point of interest are supported if device.isFocusModeSupported(.locked) { device.focusMode = .locked } if device.isFocusPointOfInterestSupported { // Map the slider value (0.0 to 1.0) to the focus point's X coordinate let focusX = CGFloat(sender.doubleValue) let focusPoint = CGPoint(x: focusX, y: 0.5) // Y coordinate is typically 0.5 (centered vertically) device.focusPointOfInterest = focusPoint } else { print("Focus point of interest is not supported on this device.") } device.unlockForConfiguration() // Log focus settings print("Focus point: \(device.focusPointOfInterest)") print("Focus mode: \(device.focusMode.rawValue)") } catch { print("Error adjusting focus: \(error)") } Any help or advice is much appreciated.
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Jan ’25
Best `AVMediaType` for depth data.
Dear Apple Developer Forum, I have a question regarding the AVCaptureDevice on iOS. We're trying to capture photos in the best quality possible along with depth data with the highest accuracy possible. We were delighted when we saw AVCaptureDevice could be initialized with the AVMediaType=.depthData which works as expected (depthData is a part of the AVCapturePhoto). When setting to AVMediaType=.video, we still receive depth data (of same quality according to our own internal tests). That confused us. Mind you, we set the device format and depth format as well: private func getDeviceFormat() throws -> AVCaptureDevice.Format { // Ensures high video format and an appropriate color profile. let format = camera?.formats.first(where: { $0.isHighPhotoQualitySupported && $0.supportedDepthDataFormats.count > 0 && $0.formatDescription.mediaSubType.rawValue == kCVPixelFormatType_420YpCbCr8BiPlanarFullRange }) // Check and see if it's available. guard format != nil else { throw CaptureDeviceError.necessaryFormatNotAvailable } return format! } private func getDepthDataFormat(for format: AVCaptureDevice.Format) throws -> AVCaptureDevice.Format { // Access the depth format. let depthDataFormat = format.supportedDepthDataFormats.first(where: { $0.formatDescription.mediaSubType.rawValue == kCVPixelFormatType_DepthFloat32 }) // Check if it exists guard depthDataFormat != nil else { throw CaptureDeviceError.necessaryFormatNotAvailable } // Returns it. return depthDataFormat! } We're wondering, what steps we can take to ensure the best quality photo, along with the most accurate depth data? What properties are the most important, which have an effect, which don't? Are there any ways we can optimize our current configuration? We find it difficult as there's very limited guides and explanations on the media subtypes, for example kCVPixelFormatType_420YpCbCr8BiPlanarFullRange. Is it the best? Is it the best for our use case of high quality photo + most accurate depth data? Important comment: Our App only runs on iPhone 14 Pro, iPhone 15 Pro, iPhone 16 Pro on the latest iOS versions. We hope someone with greater knowledge at Apple can help us and guide us on how we can have the photos of best quality and depth data with most accuracy. Thank you very much! Kind regards.
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403
Jan ’25
"Baking together" two audio tracks into one for drag-and-drop
Hi all, with my app ScreenFloat, you can record your screen, along with system- and microphone audio. Those two audio feeds are recorded into separate audio tracks in order to individually remove or edit them later on. Now, these recordings you create with ScreenFloat can be drag-and-dropped to other apps instantly. So far, so good, but some apps, like Slack, or VLC, or even websites like YouTube, do not play back multiple audio tracks, just one. So what I'm trying to do is, on dragging the video recording file out of ScreenFloat, instantly baking together the two individual audio tracks into one, and offering that new file as the drag and drop file, so that all audio is played in the target app. But it's slow. I mean, it's actually quite fast, but for drag and drop, it's slow. My approach is this: "Bake together" the two audio tracks into a one-track m4a audio file using AVMutableAudioMix and AVAssetExportSession Take the video track, add the new audio file as an audio track to it, and render that out using AVAssetExportSession For a quick benchmark, a 3'40'' movie, step 1 takes ~1.7 seconds, and step two adds another ~1.5 seconds, so we're at ~3.2 seconds. That's an eternity for a drag and drop, where the user might cancel if there's no immediate feedback. I could also do it in one step, but then I couldn't use the AV*Passthrough preset, and that makes it take around 32 seconds then, because I assume it touches the video data (which is unnecessary in this case, so I think the two-step approach here is the fastest). So, my question is, is there a faster way? The best idea I can come up with right now is, when initially recording the screen with system- and microphone audio as separate tracks, to also record both of them into a third, muted, "hidden" track I could use later on, basically eliminating the need for step one and just ripping the two single audio tracks out of the movie and only have the video and the "hidden" track (then unmuted), but I'd still have a ~1.5 second delay there. Also, there's the processing and data overhead (basically doubling the movie's audio data). All this would be great for an export operation (where one expects it to take a little time), but for a drag-and-drop operation, it's not ideal. I've discarded the idea of doing a promise file drag, because many apps do not accept those, and I want to keep wide compatibility with all sorts of apps. I'd appreciate any ideas or pointers. Thank you kindly, Matthias
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Jan ’25
photos-navigation://album scheme
In my app SexyPeri (https://apps.apple.com/fr/app/id6738291985), I create an album with some pics Album is called SexyPeri Now, I wish to redirect the user from my app SexyPeri DIRECTLY to the album SexyPeri There is no doc about your scheme photos-navigation, or I didn't see it. Some guys retro-engineered it, but I couldn't make this work. photos-navigation://album?name=SexyPeri doesn't work. So my question is: how can I redirect to the album directly ?
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Jan ’25
Torch Freezes Ultra-Wide Camera When Switching Between Wide & Ultra-Wide Lenses (AVFoundation Bug?)
I'm developing an iOS app using AVFoundation for real-time video capture and object detection. While implementing torch functionality with camera switching (between Wide and Ultra-Wide lenses), I encountered a critical issue where the camera freezes when toggling the torch while the Ultra-Wide camera is active. Issue If the torch is ON and I switch from Wide to Ultra-Wide, the camera freezes If the Ultra-Wide camera is active and I try to turn the torch ON, the camera freezes The iPhone Camera app allows using the torch while recording video with the Ultra-Wide lens, so this should be possible via AVFoundation as well. Code snippet DispatchQueue.global(qos: .userInitiated).async { [weak self] in guard let self = self else { return } let isSwitchingToUltraWide = !self.isUsingFisheyeCamera let cameraType: AVCaptureDevice.DeviceType = isSwitchingToUltraWide ? .builtInUltraWideCamera : .builtInWideAngleCamera let cameraName = isSwitchingToUltraWide ? "Ultra Wide" : "Wide" guard let selectedCamera = AVCaptureDevice.default(cameraType, for: .video, position: .back) else { DispatchQueue.main.async { self.showAlert(title: "Camera Error", message: "\(cameraName) camera is not available on this device.") } return } do { let currentInput = self.videoCapture.captureSession.inputs.first as? AVCaptureDeviceInput self.videoCapture.captureSession.beginConfiguration() if isSwitchingToUltraWide && self.isFlashlightOn { self.forceEnableTorchThroughWide() } if let currentInput = currentInput { self.videoCapture.captureSession.removeInput(currentInput) } let videoInput = try AVCaptureDeviceInput(device: selectedCamera) self.videoCapture.captureSession.addInput(videoInput) self.videoCapture.captureSession.commitConfiguration() self.videoCapture.updateVideoOrientation() DispatchQueue.main.async { if let barButton = sender as? UIBarButtonItem { barButton.title = isSwitchingToUltraWide ? "Wide" : "Ultra Wide" barButton.tintColor = isSwitchingToUltraWide ? UIColor.systemGreen : UIColor.white } print("Switched to \(cameraName) camera.") } self.isUsingFisheyeCamera.toggle() } catch { DispatchQueue.main.async { self.showAlert(title: "Camera Error", message: "Failed to switch to \(cameraName) camera: \(error.localizedDescription)") } } } } Expected Behavior Torch should be able to work when Ultra-Wide is active, just like the iPhone Camera app does. The camera should not freeze when switching between Wide and Ultra-Wide with the torch ON. AVCaptureSession should not crash when toggling the torch while Ultra-Wide is active. Questions & Help Needed Is this a known issue with AVFoundation? How does the iPhone Camera app allow using the torch while recording in Ultra-Wide? What’s the correct way to switch between Wide and Ultra-Wide cameras without freezing when the torch is active? Info Device tested: iPhone 13 Pro / iPhone 15 Pro / Iphone 15 iOS Version: iOS 17.3 / iOS 18.0 Xcode Version: 16.2
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Jan ’25
Question regarding CarPlay Integration for a Note/Voice Recording App
Hello everyone, I am currently working on an app project aimed at users who want to quickly and easily capture their ideas and notes while on the go. The basic concept is to develop an iOS app where users can store both typed notes and voice recordings – essentially a "brain dump" solution. The core functionality (storing, editing, synchronizing via CloudKit, etc.) will be handled within the iOS app. In addition, I plan to integrate a CarPlay extension that allows the driver to start and stop a recording – ideally through a minimalist interface featuring a large record button and a "Done" button. Since the iPhone is often not within immediate reach in the car, the CarPlay integration should serve as a quick trigger to initiate the recording in the iOS app. My questions are as follows: Has anyone had experience implementing a CarPlay extension for an app that primarily handles notes and voice recordings, rather than falling into the traditional categories like navigation, audio, or communication? Has such a concept ever been approved by Apple, or are there known hurdles and guidelines that must be observed? Are there alternative approaches to implementing CarPlay integration in this context in a compliant and effective manner? I would greatly appreciate any feedback, shared experiences, and tips on best practices. Thank you in advance and best regards!
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472
Feb ’25
Why do I get .ts and .aac requests to the server when playing a downloaded HLS?
I am developing an app to stream and download DRM protected HLS videos based on the official “FairPlay Streaming Server SDK”. When I play the downloaded video, it asks the server for .ts or .aac, even though I have passed the path of the downloaded video to AVURLAsset. As a result, playback fails when the device is offline, such as in airplane mode. This behavior depends on the playback time of the video and occurs when trying to download and play a video with a playback time of 19 hours or more. It did not occur for videos with a playback time of 18 hours. The environment we checked is iOS 18.3. The solution at this time is to limit the video playback time to 18 hours, but if possible, we would like to allow download playback of videos longer than 19 hours. Does anyone have any information or know of a solution to this problem, such as if you have experienced this type of event, or if you know that content longer than 19 hours cannot be played offline? // load let path = ".../xxx.movpkg" // Path of the downloaded file videoAsset = AVURLAsset(url: path) playerItem = AVPlayerItem(asset: videoAsset!) player.replaceCurrentItem(with: playerItem) // isPlayableOffline print("videoAsset.assetCache.isPlayableOffline = \(videoAsset.assetCache.isPlayableOffline)") // true
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422
Feb ’25
Improving the transition between ultra wide and wide angle lens
I'm building an app which uses the camera and want to take advantage of the ability of the builtInTripleCamera and builtInDualWideCamera to automatically switch between the ultra wide and wide angle lens to focus on close up shots. It's working fine - except that the transition between the two lenses is a bit jumpy. I looked at what the native Camera app does and it seems to apply a small amount of blurring when the transition happens to help "mask" the jumpiness. How can I replicate this, or is there another way to improve the UX of switching between one lens and another automatically?
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488
Feb ’25
AVURLAsset with AVURLAssetHTTPCookiesKey - Cookies not persisting on retry requests
I'm experiencing an unexpected behavior with AVURLAsset and cookies. When setting cookies through AVURLAssetHTTPCookiesKey option, they seem to be sent only on the initial request but not on retry attempts. Here's my current implementation: let cookieProperties: [HTTPCookiePropertyKey: Any] = [ .name: "sessionCookie", .value: "testValue", .domain: url.host ?? "", .path: "/", .secure: true ] if let cookie = HTTPCookie(properties: cookieProperties) { let asset = AVURLAsset(url: url, options: [ AVURLAssetHTTPCookiesKey: [cookie], ]) } According to the documentation, AVURLAssetHTTPCookiesKey should apply the cookies to all requests made by this asset. However, when the initial request fails and AVPlayer retries, the cookies are not included in subsequent requests. Only when I store the cookie with HTTPCookieStorage.shared.setCookie, then it persists. Questions: Is this the expected behavior? If not, what could be causing the cookies to not persist for retry attempts? Is using HTTPCookieStorage.shared the recommended approach instead? Environment: iOS 16+ Using AVPlayer with AVURLAsset Streaming HLS content Any insights would be greatly appreciated.
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351
Feb ’25
How can I add support for Apple Music lyrics sharing in my app?
I noticed that Instagram and iMessage support receiving shared lyrics from Apple Music. Specifically, when users long-press lyrics, a sheet pops up showing iMessage and Instagram. Clicking on either app generates a beautifully formatted lyrics image. I've looked through MusicKit documentation but couldn't find any related APIs. How can I implement this functionality in my app?
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Feb ’25
SCStreamDelegetate stream:didStopWithError receiving null pointer for error
I have an SCStreamDelegate for capturing frames from applications. On recent point releases of macOS Sonoma, I've noticed that the stream is being cancelled with no user action being taken. I started trying to debug it and when my on error method is called, the error parameter being passed is null: func stream(_ stream: SCStream, didStopWithError error: Error) { /*debugger shows this and segfaults if I try to print "\(error)" error (Error) > error = (Builtin.RawPointer) 0x0 */ From what I can tell, error should be a valid NSError so I can check the error code, based on similar code I've seen in, for example OBS (https://github.com/obsproject/obs-studio/blob/265239d4174f8d291b0de437088c5b78f8e27687/plugins/mac-capture/mac-sck-common.m#L29) Usually when this happens, the menubar icon for screen sharing (where I would click to change sharing window, etc) stays there even after my app has closed an no apps are doing sharing stuff. Has anyone come across this before? Am I misinterpreting what the debugger is saying about the error parameter? I'm running macos 14.7.3, but I just updated from 14.7.2 earlier and had basically the same issue on both macos versions
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Feb ’25
Missing Depth Frames When Recording with AVCaptureVideoDataOutputSampleBufferDelegate/AVCaptureDataOutputSynchronizerDelegate and AVAssetWriter
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) } }
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458
Feb ’25
MPRemoteCommandCenter not updating play/pause button to proper state on iOS
So I'm using AVAudioEngine. When playing audio I become the 'now playing' app using MPNowPlayingInfoCenter/MPRemoteCommandCenter APIs. When configuring MPRemoteCommandCenter I add a play/pause command target via -addTargetWithHandler on the togglePlayPauseCommand property. Now I also have a play/pause button in my app's UI. When I pause playback from my app's UI (which means I'm the active app, I'm in the foreground), what I do is this: -I pause the AVAudioPlayerNode I'm using with AVAudioEngine. I do not, stop, reset, etc. the AVAudioEngine. I only pause the player node. My thought process here is that the user just pressed pause and it is very likely that he will hit 'play' to resume playback in the near future because My app is in the foreground and the user just hit the pause button. Now if my app moves to the background and if I receive a memory warning I presume it'd make sense to tear down the engine or pause it. Perhaps I'm wrong about this? So when I initially hit the play button from my app's UI I also activate my AVAudioSession. I do this in high priority NSOperation since the documentation warns that "we recommend that applications not activate their session from a thread where a long blocking operation will be problematic." So now I'm playing and I hit pause from my app's UI. Then I quickly bring up the "Now Playing" center and I see I'm the "Now Playing" app but the play-pause button is showing the pause icon instead of the play icon but I'm in the pause state. I do set MPNowPlayingInfoCenter's playbackState to MPNowPlayingPlaybackStatePaused when I pause. Not surprisingly this doesn't work. The documentation states this is for macOS only. So the only way to get MPRemoteCommandCenter to show the "play" image for the play-pause button is to deactivate my AVAudioSession when I pause playback? Since I change the active state of my audio session in a NSOperation because documentation recommends "we recommend that applications not activate their session from a thread where a long blocking operation will be problematic." the play-pause toggle in the remote command center won't immediately update since I'm doing it on another thread. IMO it feels kind of inappropriate for a play-pause button to wait on a NSOperation activating the audio session before updating its UI when I already know my play/paused state, it should update right away like the button in my app does. Wouldn't it be nicer to just use MPNowPlayingInfoCenter's playbackState property on iOS too? If I'm no the longer the now playing app/active audio session it doesn't matter since I'm not in the now playing UI, just ignore it? Also is it recommended that I deactivate my audio session explicitly every time the user pauses audio in my app (when I'm in the foreground)? Also when I do deactivate the audio session I get an error: AVAudioSessionErrorCodeIsBusy (but the button in the now playing center updates to the proper image). I do this : -(void)pause { [self.playerNode pause]; [self runOperationToDeactivateAudioSession]; // This does nothing on iOS: MPNowPlayingInfoCenter *nowPlayingCenter = [MPNowPlayingInfoCenter defaultCenter]; nowPlayingCenter.playbackState = MPNowPlayingPlaybackStatePaused; } So in -runOperationToDeactivateAudioSession I get the AVAudioSessionErrorCodeIsBusy. According to the documentation Starting in iOS 8, if the session has running I/Os at the time that deactivation is requested, the session will be deactivated, but the method will return NO and populate the NSError with the code property set to AVAudioSessionErrorCodeIsBusy to indicate the misuse of the API. So pausing the player node when pausing isn't enough to meet the deactivation criteria. I guess I have to pause or stop the audio engine. I could probably wait until I receive a scene went to background notification or something before deactivating my audio session (which is async, so the button may not update to the correct image in time). This seems like a lot of code to have to write to get a play-pause toggle to update, especially in iPad-multi window scene environment. What's the recommended approach? Should I pause the AudioEngine instead of the player node always? Should I always explicitly deactivate my audio session when the user pauses playback from my app's UI even if I'm in the foreground? I personally like the idea of just being able to set [MPNowPlayingInfoCenter defaultCenter].playbackState = MPNowPlayingPlaybackStatePaused; But maybe that's because that would just make things easier on me. This does feels overcomplicated though. If anyone can share some tips on how I should handle this, I'd appreciate it.
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704
Feb ’25
Attaching depth map manually
Hi, I have a problem when I want to attach my grayscale depth map image into the real image. The produced depth map doesn't have the cameraCalibration value which should responsible to align the depth data to the image. How do I align the depth map? I saw an article about it but it is not really detailed so I might be missing some process. I tried to: convert my depth map into pixel buffer create image destination ref and add the image there. add the auxData (depth map dict) This is the output: There is some black space there and my RGB image colour changes
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403
Feb ’25