Multiple webcam capture in one avi with c# (windows forms)

Question

Hi all! I need to find a way how to make one video file from 2 or more webcam in C# (windows app). I tried to use the google for finding some samples, but no success. I found a way how to record a video from the webcam (with directshowNet, directx I can save two avi with two webcam...)

more about directShowNet:

http: //directshownet.sourceforge.net/

Sample for capturing video:

http: //www.codeproject.com/KB/directx/directshownet.aspx

For a simple example I have 2 webcams. I need to get the frames during the record, paste one frame near the other (make one image, create one frame from the two), and insert these new frames into a new avi. Any idea? Is it possible to get the frames in time, and create one new avi from the 2 captured?

Answer 1

here this code for merge 2 images

#region TakeSnap Class

 IntPtr memDc;
 [StructLayout(LayoutKind.Sequential)]
  public struct Sizes
 {
  public Int32 cx;
  public Int32 cy;

  public Sizes(Int32 x, Int32 y)
  {
   cx = x;
   cy = y;
  }
 }

 [StructLayout(LayoutKind.Sequential, Pack = 1)]
  public struct BLENDFUNCTION
 {
  public byte BlendOp;
  public byte BlendFlags;
  public byte SourceConstantAlpha;
  public byte AlphaFormat;
 }

 [StructLayout(LayoutKind.Sequential)]
  public struct Points
 {
  public Int32 x;
  public Int32 y;

  public Points(Int32 x, Int32 y)
  {
   this.x = x;
   this.y = y;
  }
 }

 [DllImport("gdi32.dll",EntryPoint="DeleteDC")]
 public static extern IntPtr DeleteDC(IntPtr hDc);

 [DllImport("gdi32.dll",EntryPoint="DeleteObject")]
 public static extern IntPtr DeleteObject(IntPtr hDc);

 [DllImport("gdi32.dll",EntryPoint="BitBlt")]
 public static extern bool BitBlt(IntPtr hdcDest,int xDest,
  int yDest,int wDest,int hDest,IntPtr hdcSource,
  int xSrc,int ySrc,int RasterOp);

 [DllImport ("gdi32.dll",EntryPoint="CreateCompatibleBitmap")]
 public static extern IntPtr CreateCompatibleBitmap(IntPtr hdc,
  int nWidth, int nHeight);

 [DllImport ("gdi32.dll",EntryPoint="CreateCompatibleDC")]
 public static extern IntPtr CreateCompatibleDC(IntPtr hdc);

 [DllImport ("gdi32.dll",EntryPoint="SelectObject")]
 public static extern IntPtr SelectObject(IntPtr hdc,IntPtr bmp);

 [DllImport("user32.dll", EntryPoint="GetDesktopWindow")]
 public static extern IntPtr GetDesktopWindow();

 [DllImport("user32.dll",EntryPoint="GetDC")]
 public static extern IntPtr GetDC(IntPtr ptr);

 [DllImport("user32.dll",EntryPoint="GetSystemMetrics")]
 public static extern int GetSystemMetrics(int abc);

 [DllImport("user32.dll",EntryPoint="GetWindowDC")]
 public static extern IntPtr GetWindowDC(Int32 ptr);

 [DllImport("user32.dll",EntryPoint="ReleaseDC")]
 public static extern IntPtr ReleaseDC(IntPtr hWnd,IntPtr hDc);

 protected static IntPtr m_HBitmap;
 public const int SM_CXSCREEN=0;
 public const int SM_CYSCREEN=1;
 public const int SRCCOPY = 13369376;

 #endregion



  private IntPtr get_pointer(string path)
 {

  Bitmap bitmap=new Bitmap(path);
  IntPtr oldBits = IntPtr.Zero;
  IntPtr screenDC = GetDC(IntPtr.Zero);
  IntPtr hBitmap = IntPtr.Zero;
  memDc = CreateCompatibleDC(screenDC);

  try
  {
   Point topLoc = new Point(Left, Top);
   Sizes bitMapSize = new Sizes(bitmap.Width, bitmap.Height);
   BLENDFUNCTION blendFunc = new BLENDFUNCTION();
   Points srcLoc = new Points(0, 0);

   hBitmap = bitmap.GetHbitmap(Color.FromArgb(0));
   IntPtr pt= SelectObject(memDc, hBitmap);
   ReleaseDC(IntPtr.Zero, screenDC);    
   return memDc;
  }
  catch(Exception ex)
  {
   return this.Handle;
  }

 }  
 public  Bitmap GetDesktopImage()
 {
  try
  {    

   Sizes size; 
   IntPtr hBitmap;   
   IntPtr  hDC = get_pointer(@"C:\Documents and Settings\admin\Desktop\11_13_40_453.jpg");    
   IntPtr hMemDC = CreateCompatibleDC(hDC);
   IntPtr  hDC1 = get_pointer(@"C:\Documents and Settings\admin\Desktop\11_13_42_906.jpg");  

   size.cx = this.Width-2;
   size.cy = this.Height-22;
   hBitmap = CreateCompatibleBitmap(hDC, size.cx*2, size.cy);   
   if (hBitmap!=IntPtr.Zero)
   {
    IntPtr hOld = (IntPtr)SelectObject(hMemDC, hBitmap);     
    BitBlt(hMemDC, 0, 0,size.cx,size.cy, hDC,0, 0,SRCCOPY); 
    BitBlt(hMemDC, size.cx, 0,size.cx,size.cy, hDC1,0, 0,SRCCOPY);
    SelectObject(hMemDC, hOld);       
    DeleteDC(hMemDC);     
    DeleteDC(memDc);     
    ReleaseDC(this.Handle, hDC);
    ReleaseDC(this.Handle, hDC1);    
    Bitmap bmp = System.Drawing.Image.FromHbitmap(hBitmap);     
    DeleteObject(hBitmap);    
    GC.Collect();    
    return bmp;
   }   
   return null;

  }
  catch(Exception ex)
  {   
   return null;
  }
 }


 private void Createimage()
 {
  try
  {
   Bitmap bm= GetDesktopImage();
   bm.Save(Application.StartupPath+"\\temp\\"+DateTime.Now.ToString("hh-mm-ss ff")+".Jpeg",System.Drawing.Imaging.ImageFormat.Jpeg);
  }
  catch(Exception ex)
  {
   MessageBox.Show(ex.Message);
  }

 }

Answer 2

CAnimateCtrl MFC Class. This is in Visual C++ 6.0. There is probably something better in the later versions.

HTH

Answer 3

The question is bit old(!) but just in case: I have successfully used AForge.NET library. In its 2.1.4 version it has a sample that displays video from two cameras.
All you have to do is instead of using default Video Player control use VideoCaptureDevice and in NewFrame events create your desired bitmap. AForge.NET even have a AVIWriter that you can use for creating output videos.