Video Picker for Unity iOS native plugin call sample, Using UIImagePickerController

VideoPicker.cs

using UnityEngine;
using System.Collections;
using System.Runtime.InteropServices;

public class VideoPicker : MonoBehaviour {

	public Texture2D shareButtonImage; // Use this for initialization

	[DllImport("__Internal")]
	private static extern void OpenVideoPicker(string game_object_name, string function_name);
	
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
	
	}

	void OnGUI ()
	{
		if (GUILayout.Button (shareButtonImage, GUIStyle.none, GUILayout.Width (128), GUILayout.Height (128))) {
			OpenVideoPicker( "GameObject", "VideoPicked" );
		}
	}

	void VideoPicked( string path ){
		Debug.Log ("---->VideoPicked");
		Debug.Log( path );
	}
}

VideoPicker.mm

#import <UIKit/UIKit.h>
#import <MobileCoreServices/MobileCoreServices.h>

#if UNITY_VERSION <= 434
#import "iPhone_View.h"

#endif

char video_url_path[1024];

@interface NonRotatingUIImagePickerController : UIImagePickerController


@end

@implementation NonRotatingUIImagePickerController
- (NSUInteger)supportedInterfaceOrientations{
    return UIInterfaceOrientationMaskLandscape;
}
@end


//-----------------------------------------------------------------

@interface APLViewController : UIViewController <UINavigationControllerDelegate, UIImagePickerControllerDelegate>{

    UIImagePickerController *imagePickerController;
@public
    const char *callback_game_object_name ;
    const char *callback_function_name ;
}

@end


@implementation APLViewController


- (void)viewDidLoad
{
    [super viewDidLoad];

    [self showImagePickerForSourceType:UIImagePickerControllerSourceTypePhotoLibrary];

}


- (void)showImagePickerForSourceType:(UIImagePickerControllerSourceType)sourceType
{
    imagePickerController = [[UIImagePickerController alloc] init];
    imagePickerController.modalPresentationStyle = UIModalPresentationCurrentContext;
    imagePickerController.sourceType = sourceType;
    imagePickerController.mediaTypes = [[NSArray alloc] initWithObjects:(NSString *)kUTTypeMovie,nil];
    
    imagePickerController.delegate = self;
    
    [self.view addSubview:imagePickerController.view];
}


#pragma mark - UIImagePickerControllerDelegate

// This method is called when an image has been chosen from the library or taken from the camera.
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    
    NSString *type = [info objectForKey:UIImagePickerControllerMediaType];
    //NSLog(@"type=%@",type);
    if ([type isEqualToString:(NSString *)kUTTypeVideo] ||
        [type isEqualToString:(NSString *)kUTTypeMovie])
    {// movie != video
        NSURL *urlvideo = [info objectForKey:UIImagePickerControllerMediaURL];
        NSLog(@"%@", urlvideo);
        NSString *urlString = [urlvideo absoluteString];
        const char* cp = [urlString UTF8String];
        strcpy(video_url_path, cp);
    }

    [self dismissViewControllerAnimated:YES completion:NULL];
    
    // UnitySendMessage("GameObject", "VideoPicked", video_url_path);
    UnitySendMessage(callback_game_object_name, callback_function_name, video_url_path);
}


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


@end





extern "C" {

    void OpenVideoPicker(const char *game_object_name, const char *function_name) {
        
        
        if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
            // APLViewController
            UIViewController* parent = UnityGetGLViewController();
            APLViewController *uvc = [[APLViewController alloc] init];
            uvc->callback_game_object_name = strdup(game_object_name) ;
            uvc->callback_function_name = strdup(function_name) ;
            [parent presentViewController:uvc animated:YES completion:nil];
        }
    }
}

What does the header file look like for this?