Question 68584 in IOS Swift Question posted in
The official documentation can be found here.

OpenCV in iOS: Class VideoWriter is implemented in both AutoLoop.framework and Runner.app. One of the two will be used. Which one is undefined – Ios swift

I have an ios app that uses opencv and some other libraries. When running it, I see a log:

(lldb) objc[536]: Class VideoWriter is implemented in both /System/Library/PrivateFrameworks/AutoLoop.framework/AutoLoop (0x1f897bd48) and /private/var/containers/Bundle/Application/6AF089E9-121C-41B4-8706-3F63E9F39090/Runner.app/Runner (0x1057a7888). One of the two will be used. Which one is undefined.

Surely, I can do nothing with AutoLoop.framework. But for the Runner.app/Runner (which is indeed the name of my app since I am using Flutter), I hope I can change it. However, I have searched through all my code and see I do not define VideoWriter by myself. With more searching, it seems the OpenCV defines that (please correct me if I am wrong!). The clue is: At opencv2.framework/Modules/opencv2.swiftmodule/arm64-apple-ios.swiftinterface I see –

...
extension VideoWriter {
  @nonobjc public convenience init(filename: Swift.String, fourcc: Swift.Int32, fps: Swift.Double, frameSize: opencv2.Size2i, params: [Swift.Int32])
}
...

So I guess that is where VideoWriter comes from.

I do not need the videoio submodule of OpenCV, so I am happy to remove it if I can. Indeed, since I link against opencv2.framework and do not use it, it should be already stripped out and I am not sure why it is still there.

Question:

  1. Does that conflict really comes from OpenCV? Or I made a wrong conclusion?
  2. What to do to resolve the conflict?

Any help is appreciated!

Tags:

2

Answers


  1. 0

    I have the same problem as you,and I finally use CocoaPods to import OpenCV, it fix the problem

    Login or Signup to reply.
  2. 0

    Confirm that it’s a naming conflict of OpenCV. I build the framework locally without opencv.videoio module and the warning is gone.

    Just clone github.com/opencv/opencv repo and use its scripts for building:

    python3 platforms/apple/build_xcframework.py --out ./build_xcframework3 --without videoio --iphoneos_archs arm64 --iphonesimulator_archs arm64 --build_only_specified_archs

    It might be tricky if you want to use the local xcframework in podspec. And it also needs some effort to write a Pacakage.swift.

    I just manually imported the opencv2.xcframework and added some builtin frameworks such as Accelerate CoreGraphics CoreImage CoreMedia into the Link Binary With Libraries of project settings.

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search