ios - 如何在ios中为普通视频添加黑白、复古等视觉效果

Question

电影在 MPMoviePlayerController 中播放得很好。但是当我按下按钮时，视频必须改变黑白或复古效果。

- (IBAction)videoCameraRoll:(id)sender
{
    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
    imagePicker.delegate = self;
    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    imagePicker.mediaTypes = [[NSArray alloc] initWithObjects:(NSString *)kUTTypeMovie,      nil];
    [self presentViewController:imagePicker animated:YES completion:NULL];

}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    NSURL *movieURL;
    NSString *mediaType = [info objectForKey: UIImagePickerControllerMediaType];
    if (CFStringCompare ((__bridge CFStringRef) mediaType, kUTTypeMovie, 0) == kCFCompareEqualTo)
    {
        movieURL=(NSURL*)[info objectForKey:UIImagePickerControllerMediaURL];
    }
    movieController =  [[MPMoviePlayerController alloc] initWithContentURL:movieURL];
    movieController.view.frame = CGRectMake(0, 56, 320, 200);
    movieController.controlStyle = MPMovieControlStyleEmbedded;
    movieController.shouldAutoplay = YES;
    movieController.scalingMode=MPMovieScalingModeFill;
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(moviePlayBackDidFinish:)
                                                 name:MPMoviePlayerPlaybackDidFinishNotification
                                               object:self.movieController];

    [self.view addSubview:movieController.view];
    [movieController prepareToPlay];
    [movieController setFullscreen:NO animated:NO];


    [picker dismissViewControllerAnimated:YES completion:NULL];
}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [picker dismissViewControllerAnimated:YES completion:NULL];
}

// Video Play Back Did Finish
- (void)moviePlayBackDidFinish:(NSNotification *)notification {

    [[NSNotificationCenter defaultCenter]removeObserver:self name:MPMoviePlayerPlaybackDidFinishNotification object:nil];
    [self.movieController stop];
    [self.movieController.view removeFromSuperview];
    self.movieController = nil;
}