UIImagePickerController不尊重iPad上的UIImagePickerControllerQualityType

Question

我正在尝试构建一个应用程序，让用户从iPad上的库中挑选和上传视频。我需要视频分辨率为960x540。

我使用以下代码：

UIImagePickerController *mediaPicker = [[UIImagePickerController alloc] init];

mediaPicker.mediaTypes = [NSArray arrayWithObjects:(NSString *)kUTTypeMovie,(NSString *)kUTTypeImage,nil];
mediaPicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;

mediaPicker.videoQuality = UIImagePickerControllerQualityTypeIFrame960x540;
mediaPicker.videoMaximumDuration = 30.0f;
mediaPicker.delegate = self;


if (self.imagePickerPopOverController.popoverVisible) {
    [self.imagePickerPopOverController dismissPopoverAnimated:YES];
}

self.imagePickerPopOverController = [[UIPopoverController alloc] initWithContentViewController:mediaPicker];
[self.imagePickerPopOverController presentPopoverFromBarButtonItem:self.navigationItem.rightBarButtonItem
                                          permittedArrowDirections:UIPopoverArrowDirectionUp
                                                          animated:NO];

当我使用上面的代码从相机中选择图像时，尺寸为960x540，但是当我在图库中执行相同操作时，其尺寸为640x360。