Capturing more than one display is no longer working with macOS Sequoia.
We have a product that allows users to capture up to 2 displays/screens. Our application is using gstreamer which in turn is based on AVFoundation.
I found a quick way to replicate the issue by just running 2 captures from separate terminals. Assuming display 1 has device index 0, and display 2 has device index 1, here are the steps:
install gstreamer with
brew install gstreamer
Then open 2 terminal windows and launch the following processes:
terminal 1 (device-index:0):
gst-launch-1.0 avfvideosrc -e device-index=0 capture-screen=true ! queue ! videoscale ! video/x-raw,width=640,height=360 ! videoconvert ! osxvideosink
terminal 2 (device-index:1):
gst-launch-1.0 avfvideosrc -e device-index=1 capture-screen=true ! queue ! videoscale ! video/x-raw,width=640,height=360 ! videoconvert ! osxvideosink
The first process that is launched will show the screen, the second process launched will not.
Testing this on macOS Ventura and Sonoma works as expected, showing both screens.
I submitted the same issue on Feedback Assistant: FB15900976
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After 18.2 IOS update, videos are not playing in Netflix, Amazon Prime and youtube
Topic:
Media Technologies
SubTopic:
Video
Hi I'm working on a project that require video frame PTS to be consistent between original video and a transcoded one. It's working fairly well on regular mp4, however if I set preferredOutputSegmentInterval to have generate a fMP4 output, even I specified the initialSegmentStartTime as 0, it always add one frame pts offset to all frames.
For example: if I use the code sample provided by Apple: https://developer.apple.com/videos/play/wwdc2020/10011/?time=406, useffprobe -select_streams v:0 -show_entries packet=pts_time -of csv ~/Downloads/fmp4/prog_index.m3u8 to display the pts of the output, it doesn't start from 0, but has some one frame pts offset. I also tried open with MP4Box, it also shows the first frames dts and cts are not start from 0.
However, if I use AVAssetReader to read the same output video, and get the PTS from 1st frame, it's returning 0. So I can't use it to calculate the pts difference between 2 videos neither.
Can I get some help to understand why there is difference between AVAssetWriter/Reader fMP4's pts and others like ffprobe?
We integrate with FCP X using a custom share destination and the Apple Script interface. This has been working fine until the the recent version 11 update of FCP X.
With this update we are no longer receiving the open event when the export has completed. We get the apple event to creat the Asset and the file is exported to the location we set in the response. There is just no open event after that. I suspect something is wrong with our scripting support but I have no idea what or how to troubleshoot.
This works fine in 10.8.1 and below.
Hello,
I’m experiencing an issue with video playback in my Javascript (SvelteKit) application using Capacitor. The video plays and loops correctly on Android and web browsers (including Safari) but stops unexpectedly after a few iterations on iOS native App.
<video src={videoPath} autoplay muted loop playsinline
class="h-auto w-full max-w-full object-cover"></video>
Has anyone encountered a similar issue or have insights into what might be causing this behavior on iOS?
Any suggestions or workarounds would be greatly appreciated. Maybe it has something to do with the iOS power saving policy?
Thank you in advance for your help!
I’m experiencing a crash at runtime when trying to extract audio from a video. This issue occurs on both iOS 18 and earlier versions. The crash is caused by the following error:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '*** -[AVAssetExportSession exportAsynchronouslyWithCompletionHandler:] Cannot call exportAsynchronouslyWithCompletionHandler: more than once.'
*** First throw call stack:
(0x1875475ec 0x184ae1244 0x1994c49c0 0x217193358 0x217199899 0x192e208b9 0x217192fd9 0x30204c88d 0x3019e5155 0x301e5fb41 0x301af7add 0x301aff97d 0x301af888d 0x301aff27d 0x301ab5fa5 0x301ab6101 0x192e5ee39)
libc++abi: terminating due to uncaught exception of type NSException
My previous code worked fine, but it's crashing with Swift 6.
Does anyone know a solution for this?
## **Previous code:**
func extractAudioFromVideo(from videoURL: URL, exportHandler: ((AVAssetExportSession, CurrentValueSubject<Float, Never>?) -> Void)? = nil, completion: @escaping (Swift.Result<URL, Error>) -> Void) {
let asset = AVAsset(url: videoURL)
// Create an AVAssetExportSession to export the audio track
guard let exportSession = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetAppleM4A) else {
completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Failed to create AVAssetExportSession"])))
return
}
// Set the output file type and path
guard let filename = videoURL.lastPathComponent.components(separatedBy: ["."]).first else { return }
let outputURL = VideoUtils.getTempAudioExportUrl(filename)
VideoUtils.deleteFileIfExists(outputURL.path)
exportSession.outputFileType = .m4a
exportSession.outputURL = outputURL
let audioExportProgressPublisher = CurrentValueSubject<Float, Never>(0.0)
if let exportHandler = exportHandler {
exportHandler(exportSession, audioExportProgressPublisher)
}
// Periodically check the progress of the export session
let timer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { _ in
audioExportProgressPublisher.send(exportSession.progress)
}
// Export the audio track asynchronously
exportSession.exportAsynchronously {
switch exportSession.status {
case .completed:
completion(.success(outputURL))
case .failed:
completion(.failure(exportSession.error ?? NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Unknown error occurred while exporting audio"])))
case .cancelled:
completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Export session was cancelled"])))
default:
completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Unknown export session status"])))
}
// Invalidate the timer when the export session completes or is cancelled
timer.invalidate()
}
}
## New Code:
func extractAudioFromVideo(from videoURL: URL, exportHandler: ((AVAssetExportSession, CurrentValueSubject<Float, Never>?) -> Void)? = nil, completion: @escaping (Swift.Result<URL, Error>) -> Void) async {
let asset = AVAsset(url: videoURL)
// Create an AVAssetExportSession to export the audio track
guard let exportSession = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetAppleM4A) else {
completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Failed to create AVAssetExportSession"])))
return
}
// Set the output file type and path
guard let filename = videoURL.lastPathComponent.components(separatedBy: ["."]).first else { return }
let outputURL = VideoUtils.getTempAudioExportUrl(filename)
VideoUtils.deleteFileIfExists(outputURL.path)
let audioExportProgressPublisher = CurrentValueSubject<Float, Never>(0.0)
if let exportHandler {
exportHandler(exportSession, audioExportProgressPublisher)
}
if #available(iOS 18.0, *) {
do {
try await exportSession.export(to: outputURL, as: .m4a)
let states = exportSession.states(updateInterval: 0.1)
for await state in states {
switch state {
case .pending, .waiting:
break
case .exporting(progress: let progress):
print("Exporting: \(progress.fractionCompleted)")
if progress.isFinished {
completion(.success(outputURL))
}else if progress.isCancelled {
completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Export session was cancelled"])))
}else {
audioExportProgressPublisher.send(Float(progress.fractionCompleted))
}
}
}
}catch let error {
print(error.localizedDescription)
}
}else {
// Periodically check the progress of the export session
let publishTimer = Timer.publish(every: 0.1, on: .main, in: .common)
.autoconnect()
.sink { [weak exportSession] _ in
guard let exportSession else { return }
audioExportProgressPublisher.send(exportSession.progress)
}
exportSession.outputFileType = .m4a
exportSession.outputURL = outputURL
await exportSession.export()
switch exportSession.status {
case .completed:
completion(.success(outputURL))
case .failed:
completion(.failure(exportSession.error ?? NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Unknown error occurred while exporting audio"])))
case .cancelled:
completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Export session was cancelled"])))
default:
completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Unknown export session status"])))
}
// Invalidate the timer when the export session completes or is cancelled
publishTimer.cancel()
}
}
Hi all, we try migrate project to Swift 6
Project use AVPlayer in MainActor
Selection audio and subtitiles not work
Task { @MainActor in let group = try await item.asset.loadMediaSelectionGroup(for: AVMediaCharacteristic.audible)
get error: Non-sendable type 'AVMediaSelectionGroup?' returned by implicitly asynchronous call to nonisolated function cannot cross actor boundary
and second example
`if #available(iOS 15.0, *) {
player?.currentItem?.asset.loadMediaSelectionGroup(for: AVMediaCharacteristic.audible, completionHandler: { group, error in
if error != nil {
return
}
if let groupWrp = group {
DispatchQueue.main.async {
self.setupAudio(groupWrp, audio: audioLang)
}
}
})
}`
get error: Sending 'groupWrp' risks causing data races
Hey - I am developing an app that uses the camera for recording video. I put the ability to choose a framerate and resolution and all combinations work perfectly fine, except for 4k 120fps for the new iPhone 16 pro. This just shows black on the preview. I tried to record even though the preview was black, but the recording is also just a black screen. Is there anything special that needs to be done in the camera setup for 4k 120fps to work? I have my camera setup code attached. Is it possible this is a bug in Apple's code, since this works with every other combination (1080p up to 240fps and 4k up to 60fps)?
Thanks so much for the help.
class CameraManager: NSObject {
enum Errors: Error {
case noCaptureDevice
case couldNotAddInput
case unsupportedConfiguration
}
enum Resolution {
case hd1080p
case uhd4K
var preset: AVCaptureSession.Preset {
switch self {
case .hd1080p:
return .hd1920x1080
case .uhd4K:
return .hd4K3840x2160
}
}
var dimensions: CMVideoDimensions {
switch self {
case .hd1080p:
return CMVideoDimensions(width: 1920, height: 1080)
case .uhd4K:
return CMVideoDimensions(width: 3840, height: 2160)
}
}
}
enum CameraType {
case wide
case ultraWide
var captureDeviceType: AVCaptureDevice.DeviceType {
switch self {
case .wide:
return .builtInWideAngleCamera
case .ultraWide:
return .builtInUltraWideCamera
}
}
}
enum FrameRate: Int {
case fps60 = 60
case fps120 = 120
case fps240 = 240
}
let orientationManager = OrientationManager()
let captureSession: AVCaptureSession
let previewLayer: AVCaptureVideoPreviewLayer
let movieFileOutput = AVCaptureMovieFileOutput()
let videoDataOutput = AVCaptureVideoDataOutput()
private var videoCaptureDevice: AVCaptureDevice?
override init() {
self.captureSession = AVCaptureSession()
self.previewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
super.init()
self.previewLayer.videoGravity = .resizeAspect
}
func configureSession(resolution: Resolution, frameRate: FrameRate, stabilizationEnabled: Bool, cameraType: CameraType, sampleBufferDelegate: AVCaptureVideoDataOutputSampleBufferDelegate?) throws {
assert(Thread.isMainThread)
captureSession.beginConfiguration()
defer { captureSession.commitConfiguration() }
captureSession.sessionPreset = resolution.preset
if captureSession.canAddOutput(movieFileOutput) {
captureSession.addOutput(movieFileOutput)
} else {
throw Errors.couldNotAddInput
}
videoDataOutput.setSampleBufferDelegate(sampleBufferDelegate, queue: DispatchQueue(label: "VideoDataOutputQueue"))
if captureSession.canAddOutput(videoDataOutput) {
captureSession.addOutput(videoDataOutput)
// Set the video orientation if needed
if let connection = videoDataOutput.connection(with: .video) {
//connection.videoOrientation = .portrait
}
} else {
throw Errors.couldNotAddInput
}
guard let videoCaptureDevice = AVCaptureDevice.default(cameraType.captureDeviceType, for: .video, position: .back) else {
throw Errors.noCaptureDevice
}
let useDimensions = resolution.dimensions
guard let format = videoCaptureDevice.formats.first(where: { format in
let dimensions = CMVideoFormatDescriptionGetDimensions(format.formatDescription)
let isRes = dimensions.width == useDimensions.width && dimensions.height == useDimensions.height
let frameRates = format.videoSupportedFrameRateRanges
return isRes && frameRates.contains(where: { $0.maxFrameRate >= Float64(frameRate.rawValue) })
}) else {
throw Errors.unsupportedConfiguration
}
self.videoCaptureDevice = videoCaptureDevice
do {
let videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
if captureSession.canAddInput(videoInput) {
captureSession.addInput(videoInput)
} else {
throw Errors.couldNotAddInput
}
try videoCaptureDevice.lockForConfiguration()
videoCaptureDevice.activeFormat = format
videoCaptureDevice.activeVideoMinFrameDuration = CMTime(value: 1, timescale: CMTimeScale(frameRate.rawValue))
videoCaptureDevice.activeVideoMaxFrameDuration = CMTime(value: 1, timescale: CMTimeScale(frameRate.rawValue))
videoCaptureDevice.activeMaxExposureDuration = CMTime(seconds: 1.0 / 960, preferredTimescale: 1000000)
videoCaptureDevice.exposureMode = .locked
videoCaptureDevice.unlockForConfiguration()
} catch {
throw error
}
configureStabilization(enabled: stabilizationEnabled)
}`
Overlay changes color in HDR video When I’m using trying to add an overlay to an image with AVMutableVideoComposition, When the video is in HDR the overlay colors are changing and white becomes grey screen shot from original HDR video result from the code with the wrong overlay colorthe result when reducing to SDR (the right overlay color)
the distorted colorsthe way it should look(sdr)
Im creating the overlay with a CGContext
class CustomHdrCompositor: NSObject, AVVideoCompositing {
private let coreImageContext = CIContext(options: [CIContextOption.cacheIntermediates: false])
let combinedFilter = CIFilter(name: "CISourceOverCompositing")!
var sourcePixelBufferAttributes: [String: Any]? = [String(kCVPixelBufferPixelFormatTypeKey): [kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange]]
var requiredPixelBufferAttributesForRenderContext: [String: Any] =
[String(kCVPixelBufferPixelFormatTypeKey): [kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange]]
var supportsWideColorSourceFrames = true
var supportsHDRSourceFrames = true
func renderContextChanged(_ newRenderContext: AVVideoCompositionRenderContext) {
return
}
func startRequest(_ request: AVAsynchronousVideoCompositionRequest) {
guard let outputPixelBuffer = request.renderContext.newPixelBuffer() else {
print("No valid pixel buffer found. Returning.")
request.finish(with: CustomCompositorError.ciFilterFailedToProduceOutputImage)
return
}
guard let requiredTrackIDs = request.videoCompositionInstruction.requiredSourceTrackIDs, !requiredTrackIDs.isEmpty else {
print("No valid track IDs found in composition instruction.")
return
}
let sourceCount = requiredTrackIDs.count
if sourceCount > 1 {
request.finish(with: CustomCompositorError.notSupportingMoreThanOneSources)
return
}
if sourceCount == 1 {
let sourceID = requiredTrackIDs[0]
let sourceBuffer = request.sourceFrame(byTrackID: sourceID.value(of: Int32.self)!)!
let sourceCIImage = CIImage(cvPixelBuffer: sourceBuffer)
var textImage = TextLayerPlayer.instance.getTextLayerAtTimesStamp(ts:request.compositionTime.seconds)
combinedFilter.setValue(textImage, forKey: "inputImage")
if let outputImage = combinedFilter.outputImage {
let renderDestination = CIRenderDestination(pixelBuffer: outputPixelBuffer)
do {
try coreImageContext.startTask(toRender: outputImage, to: renderDestination)
} catch {
}
}
}
request.finish(withComposedVideoFrame: outputPixelBuffer)
}
}
func regularCompositionHdr(asset: AVAsset) -> AVVideoComposition
{
self.isHdr = checkHdr(asset: asset)
let avComposition = AVMutableComposition()
let composition = AVMutableVideoComposition()
composition.colorPrimaries = AVVideoColorPrimaries_ITU_R_2020
composition.colorTransferFunction = AVVideoTransferFunction_ITU_R_2100_HLG
composition.colorYCbCrMatrix = AVVideoYCbCrMatrix_ITU_R_2020
composition.renderSize = assetSize
composition.frameDuration = CMTime(value: 1, timescale: 30)
composition.customVideoCompositorClass = CustomHdrCompositor.self
composition.perFrameHDRDisplayMetadataPolicy = .propagate
return composition
}
I’m using this function to transfer the transparent CGImage to CIImage that supports HDR
func convertToHDRCIImage(from cgImage: CGImage,
maxBrightness: CGFloat = 3.0) -> CIImage? {
// Create a CIImage from the input CGImage
let baseImage = CIImage(cgImage: cgImage)
// Create HDR color adjustment filter
let colorAdjust = CIFilter(name: "CIColorMatrix")!
colorAdjust.setValue(baseImage, forKey: kCIInputImageKey)
// Calculate HDR multipliers based on maxBrightness
// This will maintain color ratios while increasing brightness
colorAdjust.setValue(CIVector(x: maxBrightness, y: 0, z: 0, w: 0), forKey: "inputRVector")
colorAdjust.setValue(CIVector(x: 0, y: maxBrightness, z: 0, w: 0), forKey: "inputGVector")
colorAdjust.setValue(CIVector(x: 0, y: 0, z: maxBrightness, w: 0), forKey: "inputBVector")
// Maintain alpha channel
colorAdjust.setValue(CIVector(x: 0, y: 0, z: 0, w: 1), forKey: "inputAVector")
guard let adjustedImage = colorAdjust.outputImage else {
return nil
}
// Apply color space transformation using CIImage's colorSpace property
let transformedImage = adjustedImage.matchedFromWorkingSpace(to: hdrWorkingSpace)!
// Create context with HDR color space
let context = CIContext(options: [
.workingColorSpace: hdrColorSpace,
.outputColorSpace: hdrColorSpace
])
// Get the image bounds
let bounds = transformedImage.extent
// Create a new pixel buffer with HDR format
var pixelBuffer: CVPixelBuffer?
let pixelBufferAttributes = [
kCVPixelBufferPixelFormatTypeKey: kCVPixelFormatType_64RGBAHalf,
kCVPixelBufferMetalCompatibilityKey: true
] as CFDictionary
CVPixelBufferCreate(kCFAllocatorDefault,
Int(bounds.width),
Int(bounds.height),
kCVPixelFormatType_64RGBAHalf,
pixelBufferAttributes,
&pixelBuffer)
guard let destinationBuffer = pixelBuffer else {
return nil
}
context.render(transformedImage,
to: destinationBuffer,
bounds: bounds,
colorSpace: hdrColorSpace)
// Create final CIImage from the HDR pixel buffer
let finalImage = CIImage(cvPixelBuffer: destinationBuffer,
options: [.colorSpace: hdrColorSpace])
return finalImage
}
When reducing the HDR to SDR it keeps the right color of the overlay with, but than it reduces the HDR effect which I want to keep
Topic:
Media Technologies
SubTopic:
Video
We have a Push To Talk application which allow user to record video and audio.
When user is recording a video using AVCaptureSession and receive's an Push To Talk call, from moment the Push To Talk call is received the audio in the video which is being captured is stopped while the video capture is still in progress.
Here after the PTT call is completed, we have tried restarting the audio session, there are no errors that are getting printed but we still don't see the audio getting restarted in video capture.
We have also tried to add a new input for AVCaptureSession we are receiving error that is resulting in video capture stopping, error mentioned below:
[OS-PLT] [CameraManager] Movie file finished with error: Error Domain=AVFoundationErrorDomain Code=-11818 "Recording Stopped" UserInfo={AVErrorRecordingSuccessfullyFinishedKey=true, NSLocalizedDescription=Recording Stopped, NSLocalizedRecoverySuggestion=Stop any other actions using the recording device and try again., AVErrorRecordingFailureDomainKey=1, NSUnderlyingError=0x3026bff60 {Error Domain=NSOSStatusErrorDomain Code=-16414 "(null)"}}, success
We have also raised a Feedback Ticket on same: https://feedbackassistant.apple.com/feedback/16050598
I see some demo show convert HDR video to SDR Pixelbuffer,such AVAssetReader、 AVVideoComposition 、AVComposition 、AVFoundation.
But In some cases,I want to render HDR Pixelbuffer and record video.
AVCaptureSession *session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetHigh;
AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if ([videoDevice isVideoHDRSupported]) {
NSError *error = nil;
if ([videoDevice lockForConfiguration:&error]) {
videoDevice.automaticallyAdjustsVideoHDREnabled = NO;
videoDevice.videoHDREnabled = YES; // 开启 HDR
[videoDevice unlockForConfiguration];
} else {
NSLog(@"Error: %@", error.localizedDescription);
}
}
Real-time processing of HDR data requires processing of video frame data (such as filters), ensuring that the processing chain supports 10-bit color depth and HDR metadata. And use imagesBuffer to object tracking, etc.
How to solve this problem?
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.
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)
}
}
Hi, I am a newbie here.
We have been given a task to build a robotic vision system to capture an immersive video in a hazed environment, which will later be played on Apple Vision Pro. I am thinking of starting with 2 or 4 basic CMOS camera sensors, such as IMX378, AR0144, or VD66GY, and designing an FPGA-based circuit to synchronously capture and store raw frame-by-frame data. Some frame initial processing such as demosaicing and filtering can also be done by the FPGA. Then, I would use software for post-processing to convert the data into a compatible video format for Apple Vision Pro.
Will this idea work? I can handle the raw data capture, but I’m unsure if this approach is feasible and what post-processing software I should use.
Thanks a lot for your suggestions!
Charlie
Topic:
Media Technologies
SubTopic:
Video
I’m currently working on a project where I capture both depth frames and RGB frames using AVCaptureDataOutputSynchronizer. Depth frames are stored as raw binary data and RGB frames are saved with AVAssetWriter.
The issue I’m facing is that AVAssetWriter enforces a fixed framerate, meaning it adds or discards frames to maintain that rate (as I understand it). This causes a desynchronization between the depth and RGB frames, which is a problem because I need each depth frame to be exactly matched with the corresponding RGB frame as they were captured.
How can I ensure that the RGB frames are saved without AVAssetWriter modifying the frame count?
I am creating an app that decodes H.265 elementary streams on iOS.
I use VideoToolBox to decode from H.265 to NV12.
The decoded data is enqueued in the CMSampleBufferDisplayLayer as a CMSampleBuffer.
However, nothing is displayed in the VideoPlayerView. It remains black.
The decoding in VideoToolBox is successful. I confirmed this by saving the NV12 data in the CMSampleBuffer to a file and displaying it using a tool.
Why is nothing displayed in the VideoPlayerView?
I can provide other source code as well.
//
// VideoPlayerView.swift
// H265Decoder
//
// Created by Kohshin Tokunaga on 2025/02/15.
//
import SwiftUI
import AVFoundation
struct VideoPlayerView: UIViewRepresentable {
// Return an H265Player as the coordinator, and start playback there.
func makeCoordinator() -> H265Player {
H265Player()
}
func makeUIView(context: Context) -> UIView {
let uiView = UIView(frame: .zero)
// Base layer for attaching sublayers
uiView.backgroundColor = .black // Screen background color (for iOS)
// Create the display layer and add it to uiView.layer
let displayLayer = context.coordinator.displayLayer
displayLayer.frame = uiView.bounds
displayLayer.backgroundColor = UIColor.clear.cgColor
uiView.layer.addSublayer(displayLayer)
// Start playback
context.coordinator.startPlayback()
return uiView
}
func updateUIView(_ uiView: UIView, context: Context) {
// Reset the frame of the AVSampleBufferDisplayLayer when the view's size changes.
let displayLayer = context.coordinator.displayLayer
displayLayer.frame = uiView.layer.bounds
// Optionally update the layer's background color, etc.
uiView.backgroundColor = .black
displayLayer.backgroundColor = UIColor.clear.cgColor
// Flush transactions if necessary
CATransaction.flush()
}
}
//
// H265Player.swift
// H265Decoder
//
// Created by Kohshin Tokunaga on 2025/02/15.
//
import Foundation
import AVFoundation
import CoreMedia
class H265Player: NSObject, VideoDecoderDelegate {
let displayLayer = AVSampleBufferDisplayLayer()
private var decoder: H265Decoder?
override init() {
super.init()
// Initial configuration for the display layer
displayLayer.videoGravity = .resizeAspect
// Initialize the decoder (delegate = self)
decoder = H265Decoder(delegate: self)
// For simple playback, set isBaseline to true
decoder?.isBaseline = true
}
func startPlayback() {
// Load the file "cars_320x240.h265"
guard let url = Bundle.main.url(forResource: "temp2", withExtension: "h265") else {
print("File not found")
return
}
do {
let data = try Data(contentsOf: url)
// Set FPS and video size as needed
let packet = VideoPacket(data: data,
type: .h265,
fps: 30,
videoSize: CGSize(width: 1080, height: 1920))
// Decode as a single packet
decoder?.decodeOnePacket(packet)
} catch {
print("Failed to load file: \(error)")
}
}
// MARK: - VideoDecoderDelegate
func decodeOutput(video: CMSampleBuffer) {
// When decoding is complete, send the output to AVSampleBufferDisplayLayer
displayLayer.enqueue(video)
}
func decodeOutput(error: DecodeError) {
print("Decoding error: \(error)")
}
}
Topic:
Media Technologies
SubTopic:
Video
Context
We develop an iOS/Apple TV app that allows to play HLS+FP Live streams (custom playback UI), some of which use the same FairPlay content key id. All FairPlay content keys are requested to the same content key server.
Implementation
Despite Apple documentation warning to not reuse AVContentKeySessions, we use only one AVContentKeySession for all channels which allows the system to reuse the content key when a content key id is met again. As seen in another thread, people seems to think this is OK.
Issue
When reusing the AVContentKeySession and the user quickly tunes channels multiple times (up to 2 or 3 times per second using gestures), an inconsistency may occur where the content key request for a previous streams is asked to the delegate after a new stream is already being prepared and its AVURLAsset already assigned as the content key session AVContentKeyRecipient. Note that the previous content key recipient is removed before the new one is added.
We also have been reported for crashes (though I haven't experienced it myself) when performing multiple channels tunings which makes us think that the AVContentKeySession should definitely not been reused.
Note: On the other hand if a new AVContentKeySession is used for each stream, the system systematically requests a content key even if previous streams have used the same content key id. In this case, neither the crash nor the inconsistency issue are observed but it dramatically increases the number of calls to the content key server.
Questions
Should AVContentKeySessions definitely not be reused? Otherwise, how to handle the inconsistency issue described above?
Hi,
I am recording video using my app. And setting up fps also using below code. But sometime video is being recorded using 20 FPS. Can someone please let me know what I am doing wrong?
private func eightBitVariantOfFormat() -> AVCaptureDevice.Format? {
let activeFormat = self.videoDeviceInput.device.activeFormat
let fpsToBeSupported: Int = 60
debugPrint("fpsToBeSupported - \(fpsToBeSupported)" as AnyObject)
let allSupportedFormats = self.videoDeviceInput.device.formats
debugPrint("all formats - \(allSupportedFormats)" as AnyObject)
let activeDimensions = CMVideoFormatDescriptionGetDimensions(activeFormat.formatDescription)
debugPrint("activeDimensions - \(activeDimensions)" as AnyObject)
let filterBasedOnDimensions = allSupportedFormats.filter({ (CMVideoFormatDescriptionGetDimensions($0.formatDescription).width == activeDimensions.width) && (CMVideoFormatDescriptionGetDimensions($0.formatDescription).height == activeDimensions.height) })
if filterBasedOnDimensions.isEmpty {
// Dimension not found. Required format not found to handle.
debugPrint("Dimension not found" as AnyObject)
return activeFormat
}
debugPrint("filterBasedOnDimensions - \(filterBasedOnDimensions)" as AnyObject)
let filterBasedOnMaxFrameRate = filterBasedOnDimensions.compactMap({ format in
let videoSupportedFrameRateRanges = format.videoSupportedFrameRateRanges
if !videoSupportedFrameRateRanges.isEmpty {
let contains = videoSupportedFrameRateRanges.contains(where: { Int($0.maxFrameRate) >= fpsToBeSupported })
if contains {
return format
} else {
return nil
}
} else {
return nil
}
})
debugPrint("allFormatsToBeSupported - \(filterBasedOnMaxFrameRate)" as AnyObject)
guard !filterBasedOnMaxFrameRate.isEmpty else {
debugPrint("Taking default active format as nothing found when filtered using desired FPS" as AnyObject)
return activeFormat
}
var formatToBeUsed: AVCaptureDevice.Format!
if let four_two_zero_v = filterBasedOnMaxFrameRate.first(where: { CMFormatDescriptionGetMediaSubType($0.formatDescription) == kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange}) {
// 'vide'/'420v'
formatToBeUsed = four_two_zero_v
} else {
// Take the first one from above array.
formatToBeUsed = filterBasedOnMaxFrameRate.first
}
do {
try self.videoDeviceInput.device.lockForConfiguration()
self.videoDeviceInput.device.activeFormat = formatToBeUsed
self.videoDeviceInput.device.activeVideoMinFrameDuration = CMTimeMake(value: 1, timescale: Int32(fpsToBeSupported))
self.videoDeviceInput.device.activeVideoMaxFrameDuration = CMTimeMake(value: 1, timescale: Int32(fpsToBeSupported))
if videoDeviceInput.device.isFocusModeSupported(.continuousAutoFocus) {
self.videoDeviceInput.device.focusMode = AVCaptureDevice.FocusMode.continuousAutoFocus
}
self.videoDeviceInput.device.unlockForConfiguration()
} catch let error {
debugPrint("\(error)" as AnyObject)
}
return formatToBeUsed
}
Hi,
I am recording a video at 240 FPS within my application and saving it to the Photos app. The recorded video retains 240 FPS in the Photos app. However, after trimming the video using the Photos app and importing it back into my app, the FPS is reduced to 30 FPS.
Steps to Reproduce:
Record a video inside the application at 240 FPS.
Save the recorded video to the Photos app.
Verify that the video retains 240 FPS in the Photos app.
Trim the video using the built-in Photos app editor.
Import the trimmed video back into the application.
The FPS of the imported video is now reduced to 30 FPS.
Code Used for Importing Video:
I am using the following code to fetch the video from the Photos app:
let options: PHVideoRequestOptions = PHVideoRequestOptions()
options.version = .current // Using `.original` preserves FPS, but I need `.current` for other changes
options.deliveryMode = .highQualityFormat
options.isNetworkAccessAllowed = true
PHImageManager.default().requestAVAsset(forVideo: self, options: options) { (avAsset, audioMix, info) in
if let urlAsset = avAsset as? AVURLAsset {
completionHandler(urlAsset.url, self)
} else {
self.askForOriginal(completionHandler: completionHandler)
}
}
Observations:
The original video retains 240 FPS until it is trimmed in the Photos app.
After trimming, the FPS automatically drops to 30 FPS when imported back into the app.
If I use options.version = .original, the FPS is preserved, but I need .current to apply other modifications.
Questions:
Is this an expected behavior of PHImageManager when requesting a video with options.version = .current?
Is there a way to preserve the original FPS while still using .current?
Are there any workarounds to extract the trimmed video without FPS reduction?
Any insights or solutions would be greatly appreciated. Thanks in advance!
No video is playing and the same error is coming. I have tried everything by resetting. Please get an update as soon as possible.
error-The operation couldn't be completed. (CoreMediaErrorDomain error -42709.)