如何在ipad应用程序中录制视频剪辑并将其存储在文档文件夹中

我有一个训练应用程序，我希望当用户单击 recordVideo 按钮时，相机应该启动来录制视频，有什么方法可以在 ipad 应用程序中执行此操作。我已经完成了音频录制，我需要进行视频录制。

//for video..
#import <MobileCoreServices/MobileCoreServices.h>
#import <AVFoundation/AVFoundation.h>
#import <MediaPlayer/Mediaplayer.h>

#import <CoreMedia/CoreMedia.h>



UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;

    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    {
        NSArray *mediaTypes = [NSArray arrayWithObject:(NSString*)kUTTypeMovie];
        picker.mediaTypes = mediaTypes ;
        picker.sourceType = UIImagePickerControllerSourceTypeCamera;
        picker.cameraCaptureMode = UIImagePickerControllerCameraCaptureModeVideo ;

        [self presentModalViewController:picker animated:NO];

        [picker release];
    }
    else
    {
        UIAlertView *alt=[[UIAlertView alloc]initWithTitle:@"Error" message:@" Camera Facility is not available with this Device" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
        [alt show];
        [alt release];
    }

用于保存到文档文件夹中，也保存在照片库中

NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString* documentsDirectory = [paths objectAtIndex:0];


        //for video
        NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];
        NSLog(@"video url-%@",videoURL);

        NSData *videoData = [NSData dataWithContentsOfURL:videoURL];

        NSString * videoName = [NSString stringWithFormat:@"student_%d_%d.mp4",stud_id,imgVidID];

        videoPath = [documentsDirectory stringByAppendingPathComponent:videoName];

        NSLog(@"video path-%@",videoPath);

        [videoData writeToFile:videoPath atomically:YES];

        NSString *sourcePath = [[info objectForKey:@"UIImagePickerControllerMediaURL"]relativePath];

        UISaveVideoAtPathToSavedPhotosAlbum(sourcePath,nil,nil,nil);

}