ios - UiVideoEditorController 改变大小

Question

我正在捕捉视频使用AVCaptureSession

然后使用编辑视频UIVideoEditorController

UIVideoEditorController *videoEditor = [[UIVideoEditorController alloc] init];
videoEditor.videoPath = recordedFile.path;
videoEditor.videoQuality = UIImagePickerControllerQualityTypeIFrame960x540;
videoEditor.delegate = self;

但是输出视频大小始终返回为 640 *360

有谁知道为什么？