I'm building a Swift video editor with AVFoundation and a custom compositor. Despite setting AVVideoComposition.frameDuration to 60 FPS, I'm seeing significant frame skipping during playback.
Console Output Shows Frame Skipping
Frame #0 at 0.0 ms (fps: 60.0)
Frame #2 at 33.333333333333336 ms (fps: 60.0)
Frame #6 at 100.0 ms (fps: 60.0)
Frame #10 at 166.66666666666666 ms (fps: 60.0)
Frame #32 at 533.3333333333334 ms (fps: 60.0)
Frame #62 at 1033.3333333333335 ms (fps: 60.0)
Frame #96 at 1600.0 ms (fps: 60.0)
Instead of frames every ~16.67ms (60 FPS), I'm getting irregular intervals, sometimes 33ms, 67ms, or hundreds of milliseconds apart.
Renderer.swift (Key Parts)
@MainActor
class Renderer: ObservableObject {
@Published var playerItem: AVPlayerItem?
private let assetManager: ProjectAssetManager?
private let compositorId: String
func buildComposition() async {
// ... load mouse moves/clicks data ...
let composition = AVMutableComposition()
let videoTrack = composition.addMutableTrack(
withMediaType: .video,
preferredTrackID: kCMPersistentTrackID_Invalid
)
var currentTime = CMTime.zero
var layerInstructions: [AVMutableVideoCompositionLayerInstruction] = []
// Insert video segments
for videoURL in videoURLs {
let asset = AVAsset(url: videoURL)
let tracks = try await asset.loadTracks(withMediaType: .video)
let assetVideoTrack = tracks.first
let duration = try await asset.load(.duration)
try videoTrack.insertTimeRange(
CMTimeRange(start: .zero, duration: duration),
of: assetVideoTrack,
at: currentTime
)
let layerInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: videoTrack)
let transform = try await assetVideoTrack.load(.preferredTransform)
layerInstruction.setTransform(transform, at: currentTime)
layerInstructions.append(layerInstruction)
currentTime = CMTimeAdd(currentTime, duration)
}
let videoComposition = AVMutableVideoComposition()
videoComposition.frameDuration = CMTime(value: 1, timescale: 60) // 60 FPS
// Set render size from first video
if let firstURL = videoURLs.first {
let firstAsset = AVAsset(url: firstURL)
let firstTrack = try await firstAsset.loadTracks(withMediaType: .video).first
let naturalSize = try await firstTrack.load(.naturalSize)
let transform = try await firstTrack.load(.preferredTransform)
videoComposition.renderSize = CGSize(
width: abs(naturalSize.applying(transform).width),
height: abs(naturalSize.applying(transform).height)
)
}
let instruction = CompositorInstruction()
instruction.timeRange = CMTimeRange(start: .zero, duration: currentTime)
instruction.layerInstructions = layerInstructions
instruction.compositorId = compositorId
videoComposition.instructions = [instruction]
videoComposition.customVideoCompositorClass = CustomVideoCompositor.self
let playerItem = AVPlayerItem(asset: composition)
playerItem.videoComposition = videoComposition
self.playerItem = playerItem
}
}
class CompositorInstruction: NSObject, AVVideoCompositionInstructionProtocol {
var timeRange: CMTimeRange = .zero
var enablePostProcessing: Bool = false
var containsTweening: Bool = false
var requiredSourceTrackIDs: [NSValue]?
var passthroughTrackID: CMPersistentTrackID = kCMPersistentTrackID_Invalid
var layerInstructions: [AVVideoCompositionLayerInstruction] = []
var compositorId: String = ""
}
class CustomVideoCompositor: NSObject, AVVideoCompositing {
var sourcePixelBufferAttributes: [String : Any]? = [
kCVPixelBufferPixelFormatTypeKey as String: Int(kCVPixelFormatType_32BGRA)
]
var requiredPixelBufferAttributesForRenderContext: [String : Any] = [
kCVPixelBufferPixelFormatTypeKey as String: Int(kCVPixelFormatType_32BGRA)
]
func renderContextChanged(_ newRenderContext: AVVideoCompositionRenderContext) {}
func startRequest(_ asyncVideoCompositionRequest: AVAsynchronousVideoCompositionRequest) {
guard let sourceTrackID = asyncVideoCompositionRequest.sourceTrackIDs.first?.int32Value,
let sourcePixelBuffer = asyncVideoCompositionRequest.sourceFrame(byTrackID: sourceTrackID),
let outputBuffer = asyncVideoCompositionRequest.renderContext.newPixelBuffer() else {
asyncVideoCompositionRequest.finish(with: NSError(domain: "VideoCompositor", code: -1))
return
}
let videoComposition = asyncVideoCompositionRequest.renderContext.videoComposition
let frameDuration = videoComposition.frameDuration
let fps = Double(frameDuration.timescale) / Double(frameDuration.value)
let compositionTime = asyncVideoCompositionRequest.compositionTime
let seconds = CMTimeGetSeconds(compositionTime)
let frameInMilliseconds = seconds * 1000
let frameNumber = Int(round(seconds * fps))
print("Frame #\(frameNumber) at \(frameInMilliseconds) ms (fps: \(fps))")
asyncVideoCompositionRequest.finish(withComposedVideoFrame: outputBuffer)
}
func cancelAllPendingVideoCompositionRequests() {}
}
VideoPlayerViewModel
@MainActor
class VideoPlayerViewModel: ObservableObject {
let player = AVPlayer()
private let renderer: Renderer
func loadVideo() async {
await renderer.buildComposition()
if let playerItem = renderer.playerItem {
player.replaceCurrentItem(with: playerItem)
}
}
}
What I've Tried
Frame skipping is consistent—exact same timestamps on every playback
Issue persists even with minimal processing (just passing through buffers)
Occurs regardless of compositor complexity
Please note that I need every frame at exact millisecond intervals for my application. Frame loss or inconsistent frameInMillisecond values are not acceptable.
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Hey everyone,
I'm stuck on a really frustrating AVFoundation problem. I'm building a video editor that uses a custom AVVideoCompositor to add effects, and I need the final output to be 60 FPS.
So basically, I create an AVMutableComposition to sequence my video clips. I create an AVMutableVideoComposition and set the frame rate to 60 FPS: videoComposition.frameDuration = CMTime(value: 1, timescale: 60)
I assign my CustomVideoCompositor class to the videoComposition.
I create an AVPlayerItem with the composition and video composition.
The Problem:
Playback Works: When I play the AVPlayerItem in an AVPlayer, it's perfect. It plays at a smooth 60 FPS, and my custom compositor's startRequest method is called 60 times per second.
Export Fails: When I try to export the exact same composition and video composition using AVAssetExportSession, the final .mp4 file is always 30 FPS (or 29.97).
I've logged inside my custom compositor during the export, and it's definitely being called 30 times per second, so it's generating the 30 frames. It seems like AVAssetExportSession is just dropping every other frame when it encodes the video.
My source videos are screen recordings which I recorded using ScreenCaptureKit itself with the minimum frame interval to be 60.
Here is my export function. I'm using the AVAssetExportPresetHighestQuality preset :-
func exportVideo(to outputURL: URL) async throws {
guard let composition = composition,
let videoComposition = videoComposition else {
throw VideoCompositionError.noValidVideos
}
try? FileManager.default.removeItem(at: outputURL)
guard let exportSession = AVAssetExportSession(
asset: composition,
presetName: AVAssetExportPresetHighestQuality // Is this the problem?
) else {
throw VideoCompositionError.trackCreationFailed
}
exportSession.outputFileType = .mp4
exportSession.videoComposition = videoComposition // This has the 60fps setting
try await exportSession.export(to: outputURL, as: .mp4)
}
I've created a bare bones sample project that shows this exact bug in action. The resulting video is 60fps during playback, but only 30fps during the export. https://github.com/zaidbren/SimpleEditor
My Question:
Why is AVAssetExportSession ignoring my 60 FPS frameDuration and defaulting to 30 FPS, even though AVPlayer respects it?
When trying to record ProRes RAW (btp2) with AVAssetWriter I get several types of errors: -12780 or -11875.
I wonder if recording ProRes RAW can only be done through AVCaptureMovieFileOutput, or if there a way to correctly configure AVAssetWriter to do it.
I'm using the SwiftUI Photos Picker to select videos from the users Photos library and then opening the video using the PhotosPickerItem.
I'm looking for a way to allow the user to open the same video on their other devices as the app uses SwiftData and CloudKit to provide access to a recently watched list of videos.
The URL from the PhotosPickerItem appears to be device specific and so I was looking to see if I can use the itemIdentifier and then the init that takes the itemIdentifier to create the PhotosPickerItem on the other devices. The itemIdentifier however is always nil and so wouldn't be able to be used in this way.
Is there an alternative approach whereby the users can open a video using a PhotosPickerItem and that item would be viewable on their other devices with an item identifier or a URL that is device agnostic. This approach should also not involve copying the video into other storage as it would simply expand the use of the users iCloud storage, providing a less than ideal user experience.
If the user has opened the video from their Photos library, there should be a way to allow the same user (e.g. same Apple ID), to use the same app on another device to open the video again.
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?
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.
I’m getting Auto Layout constraint conflict warnings related to AVPlayerView in my project.
I’ve reproduced the issue on macOS Tahoe 26.2.
The conflict appears to originate inside AVPlayerView itself, between its internal subviews, rather than in my own layout code.
This issue can be easily reproduced in an empty project by simply adding an AVPlayerView as a subview using the code below.
class ViewController: NSViewController {
override func viewDidLoad() {
super.viewDidLoad()
let playerView = AVPlayerView()
view.addSubview(playerView)
}
}
After presenting that view controller, the following Auto Layout constraint conflict warnings appear in the console:
Conflicting constraints detected: <decode: bad range for [%@] got [offs:346 len:1057 within:0]>.
Will attempt to recover by breaking <decode: bad range for [%@] got [offs:1403 len:81 within:0]>.
Unable to simultaneously satisfy constraints:
(
"<NSLayoutConstraint:0xb33c29950 H:|-(0)-[AVDesktopPlayerViewContentView:0x10164dce0](LTR) (active, names: '|':AVPlayerView:0xb32ecc000 )>",
"<NSLayoutConstraint:0xb33c299a0 AVDesktopPlayerViewContentView:0x10164dce0.right == AVPlayerView:0xb32ecc000.right (active)>",
"<NSAutoresizingMaskLayoutConstraint:0xb33c62850 h=--& v=--& AVPlayerView:0xb32ecc000.width == 0 (active)>",
"<NSLayoutConstraint:0xb33d46df0 H:|-(0)-[AVEventPassthroughView:0xb33cfb480] (active, names: '|':AVDesktopPlayerViewContentView:0x10164dce0 )>",
"<NSLayoutConstraint:0xb33d46e40 AVEventPassthroughView:0xb33cfb480.trailing == AVDesktopPlayerViewContentView:0x10164dce0.trailing (active)>",
"<NSLayoutConstraint:0xb33ef8320 NSGlassView:0xb33ed8c00.trailing == AVEventPassthroughView:0xb33cfb480.trailing - 6 (active)>",
"<NSLayoutConstraint:0xb33ef8460 NSGlassView:0xb33ed8c00.width == 180 (active)>",
"<NSLayoutConstraint:0xb33ef84b0 NSGlassView:0xb33ed8c00.leading >= AVEventPassthroughView:0xb33cfb480.leading + 6 (active)>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0xb33ef8460 NSGlassView:0xb33ed8c00.width == 180 (active)>
Set the NSUserDefault NSConstraintBasedLayoutVisualizeMutuallyExclusiveConstraints to YES to have -[NSWindow visualizeConstraints:] automatically called when this happens. And/or, set a symbolic breakpoint on LAYOUT_CONSTRAINTS_NOT_SATISFIABLE to catch this in the debugger.
Is it system bug or maybe someone knows how to fix that?
Thank you.
Hello Apple Community,
We are working on a real-time streaming feature where we receive chunks of raw MP4 data through a custom protocol and store them in a buffer (array). Our goal is to use these data chunks to play a continuous video stream in AVPlayer.
What We've Tried:
Custom URL Scheme with AVAssetResourceLoaderDelegate:
We implemented a custom URL scheme (customscheme://) to serve the buffered data using AVAssetResourceLoaderDelegate.
The method shouldWaitForLoadingOfRequestedResource is called only during the initial allocation. It doesn't get triggered when new chunks are appended to the buffer.
Despite appending new data to the buffer, AVPlayer doesn’t request further chunks from the delegate.
What We Need:
We are looking for a solution where:
The player continuously fetches data from the buffer as new chunks are added.
The playback remains smooth and uninterrupted, even with real-time data being appended.
Ideally, this solution works with AVPlayer while adhering to HLS-like behavior without implementing an HLS server.
Questions:
Is AVAssetResourceLoaderDelegate the right approach for this use case?
If so, how can we ensure shouldWaitForLoadingOfRequestedResource is called whenever new data is available in the buffer?
Are there alternative APIs or recommended patterns for playing real-time MP4 data chunks in AVPlayer?
Would implementing a custom FFmpeg-based player be necessary, or can this be achieved using AVPlayer and its APIs?
We appreciate any guidance, suggestions, or examples that can help us achieve this. Thank you!
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.
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?
Hello,
Is there a way to handle 403 error returned by the server, eg token expired ?
Cannot find any information about this and everything that I tried wasn't working (addObserver, NotificationCenter with .AVPlayerItemNewErrorLogEntry, AVPlayerItemPlaybackStalled, ...)
Thank you very much.
Topic:
Media Technologies
SubTopic:
Video
Are serialized parameters already available inside -pluginInstanceAddedToDocument via FxParameterRetrievalAPI or are they being read later?
I have an app that has a WKWebView for watching YouTube videos. When the videos are windowed the audio seems fine, positionally as well. All perfectly.
When I fullscreen the video and it goes into the native visionOS video player the audio messes up.
It will suddenly sound like it is in your ears, or maybe even just one ear channel, or the position will be wrong. It might be fine for a moment but the second I touch the controls or move the window the sound jumps across the room, away from the window, or switches to stereo.
Sometimes exiting windows entirely you will still hear the videos playing. Even if you open the window back up and go to another screen and open another video, now you hear 2 videos playing at the same time with no way to stop the first one in the background, requiring to force restart the app.
It is all sorts of glitchy. I haven't the slightest clue what is happening here. I am strongly feeling this is a visionOS bug.
I tried using AVAudioSession to change some of the sound settings, and that makes zero difference in behavior.
Multiple testers have also reported this behavior and it has been seen on both visionOS 2.3 and 2.4 betas.
Thanks for the help! This is driving me mad! It is extremely consistent behavior!
I am working on a project for macOS where I am taking an AVCaptureSession's CVPixelBuffer and I need to convert it into a MTLTexture for rendering. On macOS the pixel format is 2vuy, there does not seem to be a clear format conversion while converting to a metal texture. I have been able to convert it to a texture but the color space seems to be off as it is rendering distorted colors with a double image.
I believe 2vuy is a single pane color space and I have tried to account for that, but I am unaware of what is off.
I have attached The CVPixelBuffer and The distorted MTLTexture along with a laundry list of errors.
On iOS my conversions are fine, it is only the macOS 2vuy pixel format that seems to have issues.
My code for the conversion is also attached.
If there are any suggestions or guidance on how to properly convert a 2vuy CVPixelBuffer to a MTLTexture I would greatly appreciate it.
Many Thanks
Conversion_Logs.txt
ConversionCode.swift
When I play an m3u8 video using AVPlayer, it can play smoothly at 2x speed. However, when I set it to 3x speed, the playback is not smooth and there is no sound.
Topic:
Media Technologies
SubTopic:
Video
As of iOS 18, as far as I can tell, it appears there's still no AVPlayer options that allow users to toggle the caption / subtitle track on and off. Does anyone know of a way to do this with AVPlayer or with SwiftUI's VideoPlayer?
The following code reproduces this issue. It can be pasted into an app playground. This is a random video and a random vtt file I found on the internet.
import SwiftUI
import AVKit
import UIKit
struct ContentView: View {
private let video = URL(string: "https://server15700.contentdm.oclc.org/dmwebservices/index.php?q=dmGetStreamingFile/p15700coll2/15.mp4/byte/json")!
private let captions = URL(string: "https://gist.githubusercontent.com/samdutton/ca37f3adaf4e23679957b8083e061177/raw/e19399fbccbc069a2af4266e5120ae6bad62699a/sample.vtt")!
@State private var player: AVPlayer?
var body: some View {
VStack {
VideoPlayerView(player: player)
.frame(maxWidth: .infinity, maxHeight: 200)
}
.task {
// Captions won't work for some reason
player = try? await loadPlayer(video: video, captions: captions)
}
}
}
private struct VideoPlayerView: UIViewControllerRepresentable {
let player: AVPlayer?
func makeUIViewController(context: Context) -> AVPlayerViewController {
let controller = AVPlayerViewController()
controller.player = player
controller.modalPresentationStyle = .overFullScreen
return controller
}
func updateUIViewController(_ uiViewController: AVPlayerViewController, context: Context) {
uiViewController.player = player
}
}
private func loadPlayer(video: URL, captions: URL?) async throws -> AVPlayer {
let videoAsset = AVURLAsset(url: video)
let videoPlusSubtitles = AVMutableComposition()
try await videoPlusSubtitles.add(videoAsset, withMediaType: .video)
try await videoPlusSubtitles.add(videoAsset, withMediaType: .audio)
if let captions {
let captionAsset = AVURLAsset(url: captions)
// Must add as .text. .closedCaption and .subtitle don't work?
try await videoPlusSubtitles.add(captionAsset, withMediaType: .text)
}
return await AVPlayer(playerItem: AVPlayerItem(asset: videoPlusSubtitles))
}
private extension AVMutableComposition {
func add(_ asset: AVAsset, withMediaType mediaType: AVMediaType) async throws {
let duration = try await asset.load(.duration)
try await asset.loadTracks(withMediaType: mediaType).first.map { track in
let newTrack = self.addMutableTrack(withMediaType: mediaType, preferredTrackID: kCMPersistentTrackID_Invalid)
let range = CMTimeRangeMake(start: .zero, duration: duration)
try newTrack?.insertTimeRange(range, of: track, at: .zero)
}
}
}
How can I setup correctly AVSampleBufferDisplayLayer for video display when I have input picture format kCVPixelFormatType_32BGRA?
Currently video i visible in simulator, but not iPhone, miss I something?
Render code:
var pixelBuffer: CVPixelBuffer?
let attrs: [String: Any] = [
kCVPixelBufferPixelFormatTypeKey as String: kCVPixelFormatType_32BGRA,
kCVPixelBufferWidthKey as String: width,
kCVPixelBufferHeightKey as String: height,
kCVPixelBufferBytesPerRowAlignmentKey as String: width * 4,
kCVPixelBufferIOSurfacePropertiesKey as String: [:]
]
let status = CVPixelBufferCreateWithBytes(
nil,
width,
height,
kCVPixelFormatType_32BGRA,
img,
width * 4,
nil,
nil,
attrs as CFDictionary,
&pixelBuffer
)
guard status == kCVReturnSuccess, let pb = pixelBuffer else { return }
var formatDesc: CMVideoFormatDescription?
CMVideoFormatDescriptionCreateForImageBuffer(
allocator: nil,
imageBuffer: pb,
formatDescriptionOut: &formatDesc
)
guard let format = formatDesc else { return }
var timingInfo = CMSampleTimingInfo(
duration: .invalid,
presentationTimeStamp: currentTime,
decodeTimeStamp: .invalid
)
var sampleBuffer: CMSampleBuffer?
CMSampleBufferCreateForImageBuffer(
allocator: kCFAllocatorDefault,
imageBuffer: pb,
dataReady: true,
makeDataReadyCallback: nil,
refcon: nil,
formatDescription: format,
sampleTiming: &timingInfo,
sampleBufferOut: &sampleBuffer
)
if let sb = sampleBuffer {
if CMSampleBufferGetPresentationTimeStamp(sb) == .invalid {
print("Invalid video timestamp")
}
if (displayLayer.status == .failed) {
displayLayer.flush()
}
DispatchQueue.main.async { [weak self] in
guard let self = self else {
print("Lost reference to self drawing")
return
}
displayLayer.enqueue(sb)
}
frameIndex += 1
}