How to solve the exception "attempted to read or write protected memory. This is often an indication that other memory is corrupt"?

See more:

C#

WPF

SDK

I am trying to create simple application (WPF Application Using C#)
I want to display the VideoFrame Comes from My camera through UltraStudio SDI in My Application

I've got the VideoFrame But I have a problem, When I am trying to Draw My Video frame Using IntPtr as Follow:

_writeable.WritePixels(new Int32Rect(0, 0, _width, _height), _tempRGBData, _height * _width * 3, _width * 3);

The Following Exception is thrown

Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

I will post my Code With My Question and I am waiting your Answers

I'm Using C# and Decklink in WPF Application

thank you in advance...

the Code as follow:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using DeckLinkAPI;
using System.Windows.Threading;
using System.Runtime.InteropServices;



namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window, IDeckLinkInputCallback
    {

        private IDeckLinkIterator _deckLinkIterator;
        private List<IDeckLink> _deckLinkList = new List<IDeckLink>();
        private IDeckLink _currentDevice = null;
        private IDeckLinkInput _deckLinkInput = null;
        IDeckLinkOutput _deckLinkOutput = null;
        private IDeckLinkScreenPreviewCallback screenPreviewCallback;
        private IDeckLinkVideoInputFrame video = null;
        private int _width = 1280;
        private int _height = 720;

        private WriteableBitmap _writeableBitmap = null;
       
        IntPtr _tempRGBData;
        //byte[] _tempRGBDataBytes;

        DispatcherTimer _timer = new DispatcherTimer();

       


        public MainWindow()
        {
            InitializeComponent();
        }
       

        void _timer_Tick(object sender, EventArgs e)
        {

            _writeableBitmap.Lock();
            unsafe
            {
                _writeableBitmap.WritePixels(new Int32Rect(0, 0, _width, _height), _tempRGBData, _height * _width * 3, _width * 3);
            }
            _writeableBitmap.Unlock();
               
           

        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            _writeableBitmap = new WriteableBitmap(_width, _height, 72, 27, PixelFormats.Bgr24, null);
            _captureImage.Source = _writeableBitmap;

            _tempRGBData = Marshal.AllocHGlobal(3 * _width * _height * Marshal.SizeOf(typeof(byte)));
            //_tempRGBDataBytes = new byte[3 * _width * _height];
            _deckLinkIterator = new CDeckLinkIterator();

            IDeckLink dl = null;
            while (true)
            {
                _deckLinkIterator.Next(out dl);

                if (dl == null)
                {
                    break;
                }
                else
                {
                    _deckLinkList.Add(dl);
                }
            }

            foreach (IDeckLink device in _deckLinkList)
            {
                String name;
                device.GetModelName(out name);
                Console.WriteLine("" + name);
            }

            _currentDevice = _deckLinkList[0];
            string displayName;
            _currentDevice.GetDisplayName(out displayName);
            _deckLinkInput = (IDeckLinkInput)_currentDevice;
            
            
            uint frameCount = 0;
            _deckLinkInput.GetAvailableVideoFrameCount(out frameCount);

            Console.WriteLine("available frame count: " + frameCount);

            IDeckLinkDisplayModeIterator displayIterator = null;
            _deckLinkInput.GetDisplayModeIterator(out displayIterator);


            _BMDDisplayModeSupport displayModeSupport;
            IDeckLinkDisplayMode displayMode = null;

            _BMDDisplayMode setDisplayMode = _BMDDisplayMode.bmdModeHD720p50;
            _BMDPixelFormat setPixelFormat = _BMDPixelFormat.bmdFormat8BitYUV;
            _BMDVideoInputFlags setInputFlag = _BMDVideoInputFlags.bmdVideoInputFlagDefault;

            _deckLinkInput.DoesSupportVideoMode(setDisplayMode, setPixelFormat, setInputFlag, out displayModeSupport, out displayMode);
            

            try
            {
                //_deckLinkInput.DisableAudioInput();
                _deckLinkInput.EnableVideoInput(setDisplayMode, setPixelFormat, setInputFlag);

            }
            catch (Exception em)
            {
                Console.WriteLine("deck link init failed: " + em.Message);
            }

            _deckLinkInput.SetCallback(this);


            Console.WriteLine("done!");

            _timer.Interval = TimeSpan.FromSeconds(1f / 30f);
            _timer.Tick += new EventHandler(_timer_Tick);
            _timer.Start();
        }

        int frameCount = 0;


        #region callbacks
        public void VideoInputFormatChanged(_BMDVideoInputFormatChangedEvents notificationEvents, IDeckLinkDisplayMode newDisplayMode, _BMDDetectedVideoInputFormatFlags detectedSignalFlags)
        {
            Console.WriteLine("video format changed!!");
        }

        public void VideoInputFrameArrived(IDeckLinkVideoInputFrame videoFrame, IDeckLinkAudioInputPacket audioPacket)
        {
            //get image data
           IntPtr pData;
           videoFrame.GetBytes(out pData);
          
              _tempRGBData = pData;
          
      
            //keeping it simple so just counting frames - this gets called 56 times then stops
            Console.WriteLine("video frame arrived!! " + frameCount);
            frameCount++;
           // System.Runtime.InteropServices.Marshal.ReleaseComObject(videoFrame);
        }
      
        #endregion





        //start stream
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            
                _deckLinkInput.StartStreams();
           
        }

        //stop stream
        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            _deckLinkInput.StopStreams();
        }

        private void Button_Click_2(object sender, RoutedEventArgs e)
        {
            _deckLinkInput.PauseStreams();
        }

        private void Button_Click_3(object sender, RoutedEventArgs e)
        {
            _deckLinkInput.FlushStreams();
        }

        private void Window_Loaded_1(object sender, RoutedEventArgs e)
        {

        }
    }

   

}

and XAML Code as Follow:

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="886.3" Width="916" Loaded="Window_Loaded">
    <Grid>
        <Button Content="Button" HorizontalAlignment="Left" Margin="65,51,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click"/>
        <Button Content="Button" HorizontalAlignment="Left" Margin="208,51,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click_1"/>
        <Button Content="Button" HorizontalAlignment="Left" Margin="368,51,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click_2"/>
        <Button Content="Button" HorizontalAlignment="Left" Margin="535,51,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click_3"/>
        <Image Name="_captureImage" HorizontalAlignment="Left" Height="408" Margin="31,96,0,0" VerticalAlignment="Top" Width="848"/>
        <Label Content="Label" HorizontalAlignment="Left" Margin="680,45,0,0" VerticalAlignment="Top" Width="184" Name="label1"/>

    </Grid>
</Window>

What I have tried:

I am trying to draw my videoFrame Using WriteableBitmap
thank you