I simply can't find documentation on how to implement live wallpaper. Questions in the forum are all outdated and with very little information. I did find this forum info describing the format and I've tried my best to create the mp4 as described: https://developer.apple.com/forums/thread/18610 My app can currently share mp4's and I can save it into my photo-library. I can't seem to use any of the mp4 for live-wallpaper though. I'm using Swift and have tried pretty much all of the AVVideoCodecType's to no awail.

I'm trying to move a video I create from images within my app from a temporary path to the photo library. I've verified that the movie exists by downloading the app data via devices/xcode and the movie then plays fine on my macbook. I've tried: UISaveVideoAtPathToSavedPhotosAlbum(             videoPath,             self,             #selector(self.video(_:didFinishSavingWithError:contextInfo:)),             nil) with Error: Optional(Error Domain=ALAssetsLibraryErrorDomain Code=-1 "Unknown error" UserInfo={NSLocalizedDescription=Unknown error, NSUnderlyingError=0x283684570 {Error Domain=ALAssetsLibraryErrorDomain Code=-1 "Unknown error" UserInfo={NSLocalizedDescription=Unknown error, NSUnderlyingError=0x283681860 {Error Domain=ALAssetsLibraryErrorDomain Code=-1 "Unknown error" UserInfo={NSLocalizedDescription=Unknown error, NSUnderlyingError=0x28366e490 {Error Domain=com.apple.photos.error Code=42001 "(null)"}}}}}}) and PHPhotoLibrary.requestAuthorization { status in       // Return if unauthorized       guard status == .authorized else {         print("Error saving video: unauthorized access")         return       }       PHPhotoLibrary.shared().performChanges({         PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: videoURL as URL)       }) { success, error in         if !success {           print("Error saving video: \(String(describing: error))")         }       }     } with Error: Domain=ALAssetsLibraryErrorDomain Code=-1 "Unknown error" UserInfo= ...... {Error Domain=com.apple.photos.error Code=42001 "(null)" both compile fine and are called, but end up giving me errors that do not help in the slightest. I have a full help request on StackOverflow with a link to the project (that it does not let me post here): https://stackoverflow.com/questions/63575539/swift-ios-save-video-to-library

I'm trying to move a video to the photo library and I'm getting very unhelpful errors. Is there any way to get more detailed error information, or is there some place I can look them up? I've verified that the movie exists by downloading the app data via devices/xcode and the movie plays fine on my macbook. I have a full help request on StackOverflow with a link to the project (that it does not let me post here): https://stackoverflow.com/questions/63575539/swift-ios-save-video-to-library I've tried:     PHPhotoLibrary.requestAuthorization { status in       // Return if unauthorized       guard status == .authorized else {         print("Error saving video: unauthorized access")         return       }       PHPhotoLibrary.shared().performChanges({         PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: videoURL as URL)       }) { success, error in         if !success {           print("Error saving video: \(String(describing: error))")         }       }     }   } with Error: Error saving video: Optional(Error Domain=PHPhotosErrorDomain Code=-1 "(null)") and UISaveVideoAtPathToSavedPhotosAlbum(             videoPath,             self,             #selector(self.video(_:didFinishSavingWithError:contextInfo:)),             nil) with Error: Domain=ALAssetsLibraryErrorDomain Code=-1 "Unknown error" UserInfo= ...... {Error Domain=com.apple.photos.error Code=42001 "(null)" both compile fine and are called. But end up giving me errors that do not help in the slightest.