How to display live video using device directx?

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C#

DirectX

SDK

I am trying to display live video Using UltraStudio SDI Connected Via USB3 to my computer and connected via SDI IN to My Camera.

but when I wrote the following Code Only Black Image displays always
I want live video not black image

the Code As Follow:

<pre lang="c#">
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using DeckLinkAPI;
using Microsoft.DirectX;
using Microsoft.DirectX.Direct3D;
using System.Runtime.InteropServices;








namespace VideoGrapperUltraStudioSDI
{
    public partial class Form1 : Form, IDeckLinkInputCallback, IDeckLinkScreenPreviewCallback
    {
        private IDeckLink m_deckLink;
        private IDeckLinkInput m_deckLinkInput;
        private Device m_device;
        public static IDeckLinkDX9ScreenPreviewHelper m_ph;
      


        public unsafe Form1()
        {
            InitializeComponent();

            PresentParameters pp = new PresentParameters();



            pp.BackBufferFormat = Format.Unknown;
            pp.BackBufferCount = 2;
            pp.Windowed = true;
            pp.SwapEffect = SwapEffect.Discard;
            pp.PresentationInterval = PresentInterval.Default;


            m_device = new Device(0,
                                  DeviceType.Hardware,
                                  this,
                                  CreateFlags.SoftwareVertexProcessing,
                                   pp);

            m_ph = new CDeckLinkDX9ScreenPreviewHelper();

            m_ph.Initialize((IntPtr)m_device.UnmanagedComPointer);

            IDeckLinkIterator deckLinkIterator = new CDeckLinkIterator();

            deckLinkIterator.Next(out m_deckLink);

            m_deckLinkInput = (IDeckLinkInput)m_deckLink;

           // _BMDDisplayModeSupport displayModeSupport;
           // IDeckLinkDisplayMode displayMode = null;
          //  m_deckLinkInput.DoesSupportVideoMode(_BMDDisplayMode.bmdModeHD720p50, _BMDPixelFormat.bmdFormat8BitYUV, _BMDVideoInputFlags.bmdVideoInputFlagDefault, out displayModeSupport, out displayMode);
            //m_deckLinkInput.DoesSupportVideoMode(_BMDDisplayMode.bmdModeHD1080i5994, _BMDPixelFormat.bmdFormat8BitYUV, _BMDVideoInputFlags.bmdVideoInputFlagDefault,out displayModeSupport,out displayMode);
            m_deckLinkInput.EnableVideoInput(_BMDDisplayMode.bmdModeHD720p50, _BMDPixelFormat.bmdFormat8BitYUV, _BMDVideoInputFlags.bmdVideoInputFlagDefault);
            m_deckLinkInput.SetCallback(this);
            m_deckLinkInput.SetScreenPreviewCallback(this);
            m_deckLinkInput.StartStreams();
        }

        public void VideoInputFormatChanged(_BMDVideoInputFormatChangedEvents notificationEvents, IDeckLinkDisplayMode newDisplayMode, _BMDDetectedVideoInputFormatFlags detectedSignalFlags)
        {
            throw new NotImplementedException();
        }

        public void VideoInputFrameArrived(IDeckLinkVideoInputFrame videoFrame, IDeckLinkAudioInputPacket audioPacket)
        {
            
            
           
            
            System.Runtime.InteropServices.Marshal.ReleaseComObject(videoFrame);
        }

        public void DrawFrame(IDeckLinkVideoFrame theFrame)
        {
            m_ph.SetFrame(theFrame);

          
           /* IntPtr buffer;
           
            tagRECT rc = new tagRECT();
            theFrame.GetBytes(out buffer);
            m_device.BeginScene();
            m_ph.Render(ref rc);

            m_device.EndScene();
            m_device.Present(buffer);*/
            m_device.Present();
            
            System.Runtime.InteropServices.Marshal.ReleaseComObject(theFrame);
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void Form1_Paint(object sender, PaintEventArgs e)
        {
        }

       

        /*private void Form1_Paint(object sender, PaintEventArgs e)
        {
            timer1.Enabled = true;
            timer1.Start();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            m_device.Present();
        }*/
    }
}

I wait your response thank you,,,,

What I have tried:

I am trying to use Device.beginSence()
Device.EndSence()
Device.Render();

but that did not solve the problem