I’m building a macOS video editor that uses AVComposition and AVVideoComposition.
Initially, my renderer creates a composition with some default video/audio tracks:
@Published var composition: AVComposition?
@Published var videoComposition: AVVideoComposition?
@Published var playerItem: AVPlayerItem?
Then I call a buildComposition() function that inserts all the default video segments.
Later in the editing workflow, the user may choose to add their own custom video clip. For this I have a function like:
private func handlePickedVideo(_ url: URL) {
guard url.startAccessingSecurityScopedResource() else {
print("Failed to access security-scoped resource")
return
}
let asset = AVURLAsset(url: url)
let videoTracks = asset.tracks(withMediaType: .video)
guard let firstVideoTrack = videoTracks.first else {
print("No video track found")
url.stopAccessingSecurityScopedResource()
return
}
renderer.insertUserVideoTrack(from: asset, track: firstVideoTrack)
url.stopAccessingSecurityScopedResource()
}
What I want to achieve is the same behavior professional video editors provide,
after the composition has already been initialized and built, the user should be able to add a new video track and the composition should update live, meaning the preview player should immediately reflect the changes without rebuilding everything from scratch manually.
How can I structure my AVComposition / AVMutableComposition and my rendering pipeline so that adding a new clip later updates the existing composition in real time (similar to Final Cut/Adobe Premiere), instead of needing to rebuild everything from zero?
You can find a playable version of this entire setup at :- https://github.com/zaidbren/SimpleEditor
Video
RSS for tagDive into the world of video on Apple platforms, exploring ways to integrate video functionalities within your iOS,iPadOS, macOS, tvOS, visionOS or watchOS app.
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Activity
I want to confirm if this is a bug or a programming error. Very easy to reproduce it by modifying AVCam sample code. Steps to reproduce:
Add AVCaptureVideoDataOutput to AVCaptureSession, no need to set delegate in AVCam sample code (CaptureService actor)
private let videoDataOutput = AVCaptureVideoDataOutput()
and then in configureSession method, add the following line
try addOutput(videoDataOutput)
if videoDataOutput.availableVideoPixelFormatTypes.contains(kCVPixelFormatType_420YpCbCr8BiPlanarFullRange) {
videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as AnyHashable as! String : kCVPixelFormatType_420YpCbCr8BiPlanarFullRange]
}
And next modify set HDR method:
/// Sets whether the app captures HDR video.
func setHDRVideoEnabled(_ isEnabled: Bool) {
// Bracket the following configuration in a begin/commit configuration pair.
captureSession.beginConfiguration()
defer { captureSession.commitConfiguration() }
do {
// If the current device provides a 10-bit HDR format, enable it for use.
if isEnabled, let format = currentDevice.activeFormat10BitVariant {
try currentDevice.lockForConfiguration()
currentDevice.activeFormat = format
currentDevice.unlockForConfiguration()
isHDRVideoEnabled = true
if videoDataOutput.availableVideoPixelFormatTypes.contains(kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange) {
videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as AnyHashable as! String : kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange]
}
} else {
captureSession.sessionPreset = .high
isHDRVideoEnabled = false
if videoDataOutput.availableVideoPixelFormatTypes.contains(kCVPixelFormatType_32BGRA) {
print("Setting sdr pixel format \(kCVPixelFormatType_32BGRA)")
videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as AnyHashable as! String : kCVPixelFormatType_32BGRA]
}
try currentDevice.lockForConfiguration()
currentDevice.activeColorSpace = .sRGB
currentDevice.unlockForConfiguration()
}
} catch {
logger.error("Unable to obtain lock on device and can't enable HDR video capture.")
}
The problem now is toggling HDR on and off no longer works in video mode. If after setting HDR on, you set HDR to off, active format of device does not change (setting sessionPreset has no effect). This does not happen if video data output is not added to session.
Is there any workaround available?
hello, I'm using VideoTololbox VTFrameRateConversionConfiguration to perform frame interpolation: https://developer.apple.com/documentation/videotoolbox/vtframerateconversionconfiguration?language=objc ,when using 640x480 vidoe input, I got error:
Error ! Invalid configuration
[VEEspressoModel] build failure : flow_adaptation_feature_extractor_rev2.espresso.net. Configuration: landscape640x480
[EpsressoModel] Cannot load Net file flow_adaptation_feature_extractor_rev2.espresso.net. Configuration: landscape640x480
Error: failed to create FRCFlowAdaptationFeatureExtractor for usage 8
Failed to switch (0x12c40e140) [usage:8, 1/4 flow:0, adaptation layer:1, twoStage:0, revision:2, flow size (320x240)].
Could not init FlowAdaptation
initFlowAdaptationWithError fail
tried 2048x1080 is ok.
Avplayer encapsulates a player. After connecting to an Apple Bluetooth headset, it immediately reports an error. Non-Apple Bluetooth headsets can be played, but currently the issue is that the player works normally in one app but not in another. We are an educational app.
Hello, I requested Fairplay credentials a week ago. Where can I check the status of my request? Thank you very much.
The team ID is: 6WZ8SVRYV9
We’re developing an AVFoundation-based video recording app (4K @ 60 fps required for biomechanical analysis). On most devices this works perfectly (iPhone 12/14/15/16 non-Pro models), but on several iPhone Pro models (12 Pro, 13 Pro, 14 Pro, 15 Pro/Pro Max), we consistently get 4K 30 fps recordings—even when the device should support 4K 60 fps on the wide-angle camera.
What we observe
We configure the session for .hd4K3840x2160.
We iterate through AVCaptureDevice.formats and select formats that:
have 3840×2160 resolution
support ≥60 fps (videoSupportedFrameRateRanges)
On some Pro devices, this format search returns no results, even though:
The Camera app records 4K60 fine.
External references list the wide camera as 4K60 capable.
The fallback becomes the device's default 4K30 format, so final files are 3840×2160 @ 30 fps.
This happens immediately on app launch (not after heating), so not thermal-related.
What we’ve tried
Force selecting .builtInWideAngleCamera instead of dual/triple cameras.
Disabling HDR (videoHDREnabled = false).
Disabling low-light boost.
Allowing 59.94 fps formats (in case exact 60.0 isn’t exposed).
Logging all videoSupportedFrameRateRanges per format.
What we’re seeing in logs
On affected Pro devices, the capture device reports only 4K formats with maxFrameRate ≈ 30 fps, despite the hardware being able to do 4K60.
Main question
Has anyone encountered cases where 4K60 formats are available in the Camera app but not exposed through AVFoundation, especially on Pro models or multi-camera devices?
Could HEVC/HDR capability or multi-camera constraints be preventing certain formats from appearing?
Are there known conditions where 4K60 formats are hidden unless specific device configuration is applied?
Any guidance on reliably locking 4K60 on iPhone Pro models via AVFoundation would be hugely appreciated.
I have found that following code runs without issue from Xcode, either in Debug or Release mode, yet crashes when running from the binary produced by archiving - i.e. what will be sent to the app store.
import SwiftUI
import AVKit
@main
struct tcApp: App {
var body: some Scene {
WindowGroup {
VideoPlayer(player: nil)
}
}
}
This is the most stripped down code that shows the issue. One can try and point the VideoPlayer at a file and the same issue will occur.
I've attached the crash log:
Crash log
Please note that this was seen with Xcode 26.2 and MacOS 26.2.