EXPORTSTATUS4ErrorDomain=AVFoundationErrorDomainCode=-11820"CannotCompleteExport"UserInfo={NSLocalizedDescription=CannotCompleteExport,NSLocalizedRecoverySuggestion=Tryexportingagain.}尝试导出包含AVMutableVideoCompositionLayerInstruction的AVMutableComposition和使用的AVMutableVideoComposition时遇到间歇性错误AVAsset