iOS mov格式转mp4格式AVFoundationError

Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo={NSUnderlyingError=0x282ce4630 {Error Domain=NSOSStatusErrorDomain Code=-16979 "(null)"}, NSLocalizedFailureReason=An unknown error occurred (-16979), NSURL=file:///var/mobile/Containers/Data/Application/248FF378-F84D-4870-8D34-4B04BBCAAF62/Library/Caches/cache/video_181228_input.mov, NSLocalizedDescription=The operation could not be completed}

出现此错误提示可能是
1.本地的mov 视频源被NSFileManager 提前删除,因此需要早转换成功后进行删除处理。
2.尽量保证本地mov 地址与 mp4输出地址在同一文件夹下。