AVAssetExportSession Trouble with iOS 17

[helgehoi]

Hi again,

You were so helpful last time around. Thank you!

I have another question - when trying out IOS 17 beta (tried both 4 and 5), the export function fails with the following error:
"Error Domain=NSCocoaErrorDomain Code=257 "The file couldn’t be opened because you don’t have permission to view it."

It works well on iOS 16, but generates a .failed in iOS17 in the AVAssetExportSession exportAsynchronously closure.

Have you seen the same behavior? Any idea on how to fix this?

Thanks in advance

[orchetect]

I think you mean when using AVAssetExportSession from this discussion post?

This may be an iOS change or bug. Or an app permission issue. It would be useful to know where this error is happening exactly in code.

[orchetect]

It looks like a file permission error that probably isn't related to TimecodeKit.

Can you log the URLs to the console so see what they are? fromFileUrl, newFilePath

[helgehoi]

Both URLs look just fine. And as mentioned, on iOS 16 this works as a charm. The error only shows up on iOS 17 betas.

It does not seem to be related to TimecodeKit, I agree, more to the code around it to write the result to a file. I only asked you as you seem very knowledgeable about everything related.

[orchetect]

I was only interested in the URLs because their paths might provide a hint as to why we're getting permissions errors.

[orchetect]

I did a MVP test to see if I could replicate the issue. Xcode 15 beta 6 using an iPhone 14 Simulator with iOS 17 beta 5.

• Empty iOS App project
• Added a small test.mov file in the app's Resources
• Reads the test.mov file, modifies its timecode track, and exports it to a new mov file in a system-provided temporary folder

import TimecodeKit
import AVFoundation

func go() throws {
    guard let fromFileUrl = Bundle.main.url(forResource: "test", withExtension: "mov") else { print("Resource URL error") ; return }
    let movie = AVMovie(url: fromFileUrl)
    guard let mutableMovie = movie.mutableCopy() as? AVMutableMovie else { print("Mutable movie is nil") ; return }
    print(mutableMovie)
    
    let tc = try Timecode(TCC(h: 1), at: ._24)
    try mutableMovie.replaceTimecodeTrack(startTimecode: tc, fileType: .mov)
    
    let outURL = URL.temporaryDirectory.appending(component: UUID().uuidString + ".mov")
    
    let exporter = AVAssetExportSession(
        asset: mutableMovie,
        presetName: AVAssetExportPresetPassthrough
    )!
    exporter.outputFileType = .mov
    exporter.outputURL = outURL
    exporter.exportAsynchronously {
        switch exporter.status {
        case .unknown: print("unknown")
        case .waiting: print("waiting")
        case .exporting: print("exporting")
        case .completed: print("completed")
        case .failed: print("failed")
        case .cancelled: print("cancelled")
        @unknown default: print("default")
        }
        
        if let exportError = exporter.error {
            print("\(exportError)")
        }
        
        print("Output file exists:", FileManager.default.fileExists(atPath: outURL.path(percentEncoded: false)))
    }
}

Works as expected with no issues. Log output:

<AVMutableMovie: 0x60000026bf20 tracks = (
    "<AVMutableMovieTrack: 0x600000274660, trackID = 1, mediaType = vide>",
    "<AVMutableMovieTrack: 0x600000274a00, trackID = 2, mediaType = tmcd>"
) >
completed
Output file exists: true

[helgehoi]

Hi and thank you again!

I have now tried your code snippet, and on the emulator I get the same result as you, but when I run it on an iPhone with IOS 17 beta 6, I get the following:

<AVMutableMovie: 0x280fe4560 tracks = (
"<AVMutableMovieTrack: 0x280f9aba0, trackID = 1, mediaType = vide>",
"<AVMutableMovieTrack: 0x280f95680, trackID = 2, mediaType = soun>",
"<AVMutableMovieTrack: 0x280ff5a40, trackID = 3, mediaType = tmcd>"
) >
failed
Output file exists: false

Any idea why this is so? Seems to be just the same error as I experience in my app

[helgehoi]

...and when I added a bit more logging I get this:
<AVMutableMovie: 0x2803bc520 tracks = (
"<AVMutableMovieTrack: 0x2803dfc00, trackID = 1, mediaType = vide>",
"<AVMutableMovieTrack: 0x2803cb9c0, trackID = 2, mediaType = soun>",
"<AVMutableMovieTrack: 0x2803d40e0, trackID = 3, mediaType = tmcd>"
) >
failed - Optional(Error Domain=NSCocoaErrorDomain Code=257 "The file couldn’t be opened because you don’t have permission to view it." UserInfo={NSUnderlyingError=0x280d8abe0 {Error Domain=NSOSStatusErrorDomain Code=-12203 "(null)"}})
Output file exists: false

[orchetect]

Not sure what to say at this point. It sounds like it could be some condition on your system? I haven't tested with a physical device. Does it work in a simulator for you?

[helgehoi]

Yes, on the simulator everything works

[orchetect]

I've submitted a radar to Apple (#FB12986599) with all the details and an example project for them to test. We'll see if anything happens.

[orchetect]

No response from Apple yet, and issue still persists in Xcode 15 beta 8 / iOS 17 beta 8.

[orchetect]

Still failing on-device with the iOS 17 RC build / Xcode 15 RC.

[helgehoi]

Still failing on me here as well, even on the official release iOS 17.0.1

Did you ever hear back from Apple?

[orchetect]

No and I wasn't really expecting a response. They take months or sometimes years to respond, if they ever do.

[orchetect]

Great news! Apple just responded to my radar and said to try the iOS 17.1 beta that was just released.

I gave it a spin myself, and it looks like they fixed it!

<AVMutableMovie: 0x280d3c5c0 tracks = (
    "<AVMutableMovieTrack: 0x280d30800, trackID = 1, mediaType = vide>",
    "<AVMutableMovieTrack: 0x280d3c8c0, trackID = 2, mediaType = tmcd>"
) >
Output URL: file:///private/var/mobile/Containers/Data/Application/3D4897CC-F9B9-4E8B-A306-DB9B315AA7CE/tmp/757F01E0-6B9E-415D-A046-121345A5E38B.mov
completed
Output file exists: true

[helgehoi]

Awesome, thanks for the update!

…

On Fri, 29 Sep 2023 at 01:47, Steffan Andrews ***@***.***> wrote: Great news! Apple just responded to my radar and said to try the iOS 17.1 beta that was just released. I gave it a spin myself, and it looks like they fixed it! <AVMutableMovie: 0x280d3c5c0 tracks = ( "<AVMutableMovieTrack: 0x280d30800, trackID = 1, mediaType = vide>", "<AVMutableMovieTrack: 0x280d3c8c0, trackID = 2, mediaType = tmcd>" ) > Output URL: file:///private/var/mobile/Containers/Data/Application/3D4897CC-F9B9-4E8B-A306-DB9B315AA7CE/tmp/757F01E0-6B9E-415D-A046-121345A5E38B.mov completed Output file exists: true — Reply to this email directly, view it on GitHub <#63 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABOIVS7JVS7TD7B5QAD3AADX4YEBXANCNFSM6AAAAAA3J2X7UI> . You are receiving this because you authored the thread.Message ID: ***@***.***>