Develop Reference

Take screenshot and send it to printer Asp.net MVC 5

I am trying to implement the functionality of taking screenshot and sending the capture to printer. No need to implement the print functionality,user will decide whether to print or cancel that particular document. After digging around the internet and tweaking it to my requirement I am able to save the screenshot locally but unable to send it to printer.
public ActionResult About()
{
ScreenCapture sc = new ScreenCapture();
// capture entire screen, and save it to a file
Image img = sc.CaptureScreen();
// capture this window, and save it
sc.CaptureScreenToFile("C:\\temp2.png", ImageFormat.Png);
return View();
}
public class ScreenCapture
{
/// <summary>
/// Creates an Image object containing a screen shot of the entire desktop
/// </summary>
/// <returns></returns>
public Image CaptureScreen()
{
return CaptureWindow(User32.GetDesktopWindow());
}
/// <summary>
/// Creates an Image object containing a screen shot of a specific window
/// </summary>
/// <param name="handle">The handle to the window. (In windows forms, this is obtained by the Handle property)</param>
/// <returns></returns>
public Image CaptureWindow(IntPtr handle)
{
// get te hDC of the target window
IntPtr hdcSrc = User32.GetWindowDC(handle);
// get the size
User32.RECT windowRect = new User32.RECT();
User32.GetWindowRect(handle, ref windowRect);
int width = windowRect.right - windowRect.left;
int height = windowRect.bottom - windowRect.top;
// create a device context we can copy to
IntPtr hdcDest = GDI32.CreateCompatibleDC(hdcSrc);
// create a bitmap we can copy it to,
// using GetDeviceCaps to get the width/height
IntPtr hBitmap = GDI32.CreateCompatibleBitmap(hdcSrc, width, height);
// select the bitmap object
IntPtr hOld = GDI32.SelectObject(hdcDest, hBitmap);
// bitblt over
GDI32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, GDI32.SRCCOPY);
// restore selection
GDI32.SelectObject(hdcDest, hOld);
// clean up
GDI32.DeleteDC(hdcDest);
User32.ReleaseDC(handle, hdcSrc);
// get a .NET image object for it
Image img = Image.FromHbitmap(hBitmap);
// free up the Bitmap object
GDI32.DeleteObject(hBitmap);
return img;
}
/// <summary>
/// Captures a screen shot of a specific window, and saves it to a file
/// </summary>
/// <param name="handle"></param>
/// <param name="filename"></param>
/// <param name="format"></param>
public void CaptureWindowToFile(IntPtr handle, string filename, ImageFormat format)
{
Image img = CaptureWindow(handle);
img.Save(filename, format);
}
/// <summary>
/// Captures a screen shot of the entire desktop, and saves it to a file
/// </summary>
/// <param name="filename"></param>
/// <param name="format"></param>
public void CaptureScreenToFile(string filename, ImageFormat format)
{
Image img = CaptureScreen();
img.Save(filename, format);
}
/// <summary>
/// Helper class containing Gdi32 API functions
/// </summary>
private class GDI32
{
public const int SRCCOPY = 0x00CC0020; // BitBlt dwRop parameter
[DllImport("gdi32.dll")]
public static extern bool BitBlt(IntPtr hObject, int nXDest, int nYDest,
int nWidth, int nHeight, IntPtr hObjectSource,
int nXSrc, int nYSrc, int dwRop);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleBitmap(IntPtr hDC, int nWidth,
int nHeight);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleDC(IntPtr hDC);
[DllImport("gdi32.dll")]
public static extern bool DeleteDC(IntPtr hDC);
[DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);
[DllImport("gdi32.dll")]
public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);
}
/// <summary>
/// Helper class containing User32 API functions
/// </summary>
private class User32
{
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int left;
public int top;
public int right;
public int bottom;
}
[DllImport("user32.dll")]
public static extern IntPtr GetDesktopWindow();
[DllImport("user32.dll")]
public static extern IntPtr GetWindowDC(IntPtr hWnd);
[DllImport("user32.dll")]
public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);
[DllImport("user32.dll")]
public static extern IntPtr GetWindowRect(IntPtr hWnd, ref RECT rect);
}
}
Any leads/help will be appreciated. I have come across the PrintDocument class but they were mostly used in WindowsForm/WPF, was not very confident about using in MVC. Thanks in Advance

Taking screenshot of MEmu

I downloaded a class with handy methods that I use to take screenshots of other programs for a while now
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
namespace EmulatorObserver.model
{
/// <summary>
/// Provides functions to capture the entire screen, or a particular window, and save it to a file.
/// </summary>
public static class ScreenCapture
{
/// <summary>
/// Creates an Image object containing a screen shot of a specific window
/// </summary>
/// <param name="handle">The handle to the window. (In windows forms, this is obtained by the Handle property)</param>
/// <returns></returns>
public static Bitmap CaptureWindow(IntPtr handle)
{
// get te hDC of the target window
IntPtr hdcSrc = GetWindowDC(handle);
// get the size
RECT windowRect = new RECT();
GetWindowRect(handle, ref windowRect);
int width = windowRect.right - windowRect.left;
int height = windowRect.bottom - windowRect.top;
// create a device context we can copy to
IntPtr hdcDest = CreateCompatibleDC(hdcSrc);
// create a bitmap we can copy it to,
// using GetDeviceCaps to get the width/height
IntPtr hBitmap = CreateCompatibleBitmap(hdcSrc, width, height);
// select the bitmap object
IntPtr hOld = SelectObject(hdcDest, hBitmap);
// bitblt over
BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, SRCCOPY);
// restore selection
SelectObject(hdcDest, hOld);
// clean up
DeleteDC(hdcDest);
ReleaseDC(handle, hdcSrc);
// get a .NET image object for it
Bitmap raw;
using(Image img = Image.FromHbitmap(hBitmap))
{
raw = (Bitmap)img.Clone();
}
// free up the Bitmap object
DeleteObject(hBitmap);
return raw;
}
////////////////////////////////////////////////////////////////////////////////////////////
// Win32 API
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int left;
public int top;
public int right;
public int bottom;
}
public const int SRCCOPY = 0x00CC0020; // BitBlt dwRop parameter
[DllImport("user32.dll")]
public static extern IntPtr GetWindowRect(IntPtr hWnd, ref RECT rect);
[DllImport("gdi32.dll")]
public static extern bool BitBlt(IntPtr hObject, int nXDest, int nYDest, int nWidth, int nHeight, IntPtr hObjectSource, int nXSrc, int nYSrc, int dwRop);
[DllImport("user32.dll")]
public static extern IntPtr GetWindowDC(IntPtr hWnd);
[DllImport("gdi32.dll")]
public static extern bool DeleteDC(IntPtr hDC);
[DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);
[DllImport("gdi32.dll")]
public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleBitmap(IntPtr hDC, int nWidth, int nHeight);
[DllImport("user32.dll")]
public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleDC(IntPtr hDC);
}
}
so far it worked nicely, but when trying to take a screenshot of an Android emulator MEmu
the resulting picture looks like this
what can I not take a screenshot of the content by running 'ScreenCapture.CaptureWindow(h).Save(#"screenshot.bmp");' ? what way do I have to (quickly) get these pictures?

Screenshot of all open windows

I'm trying to save screenshot of all the open windows on windows 7.
Issue is that instead of getting screenshot of open windows, it's giving me cmd.exe screenshot. (For example instead of taking google chrome screenshot it shows black cmd.exe screenshot).
I tried the same code on windows 10 before and it seemed to be working.
I have used following code from the http://www.developerfusion.com/code/4630/capture-a-screen-shot/ to get the screenshot of a particular window.
namespace ScreenShotDemo
{
/// <summary>
/// Provides functions to capture the entire screen, or a particular window, and save it to a file.
/// </summary>
public class ScreenCapture
{
/// <summary>
/// Creates an Image object containing a screen shot of the entire desktop
/// </summary>
/// <returns></returns>
public Image CaptureScreen()
{
return CaptureWindow(User32.GetDesktopWindow());
}
/// <summary>
/// Creates an Image object containing a screen shot of a specific window
/// </summary>
/// <param name="handle">The handle to the window. (In windows forms, this is obtained by the Handle property)</param>
/// <returns></returns>
public Image CaptureWindow(IntPtr handle)
{
// get te hDC of the target window
IntPtr hdcSrc = User32.GetWindowDC(handle);
// get the size
//User32.RECT windowRect = new User32.RECT();
//User32.GetWindowRect(handle, ref windowRect);
//int width = windowRect.right - windowRect.left;
//int height = windowRect.bottom - windowRect.top;
User32.WINDOWINFO info = new User32.WINDOWINFO();
User32.GetWindowInfo(handle, ref info);
int width = info.rcWindow.right - info.rcWindow.left;
int height = info.rcWindow.bottom - info.rcWindow.top;
// create a device context we can copy to
IntPtr hdcDest = GDI32.CreateCompatibleDC(hdcSrc);
// create a bitmap we can copy it to,
// using GetDeviceCaps to get the width/height
IntPtr hBitmap = GDI32.CreateCompatibleBitmap(hdcSrc, width, height);
// select the bitmap object
IntPtr hOld = GDI32.SelectObject(hdcDest, hBitmap);
// bitblt over
GDI32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, GDI32.SRCCOPY);
// restore selection
GDI32.SelectObject(hdcDest, hOld);
// clean up
GDI32.DeleteDC(hdcDest);
User32.ReleaseDC(handle, hdcSrc);
// get a .NET image object for it
Image img = Image.FromHbitmap(hBitmap);
// free up the Bitmap object
GDI32.DeleteObject(hBitmap);
return img;
}
/// <summary>
/// Captures a screen shot of a specific window, and saves it to a file
/// </summary>
/// <param name="handle"></param>
/// <param name="filename"></param>
/// <param name="format"></param>
public void CaptureWindowToFile(IntPtr handle, string filename, ImageFormat format)
{
Image img = CaptureWindow(handle);
img.Save(filename, format);
}
/// <summary>
/// Captures a screen shot of the entire desktop, and saves it to a file
/// </summary>
/// <param name="filename"></param>
/// <param name="format"></param>
public void CaptureScreenToFile(string filename, ImageFormat format)
{
Image img = CaptureScreen();
img.Save(filename, format);
}
/// <summary>
/// Helper class containing Gdi32 API functions
/// </summary>
private class GDI32
{
public const int SRCCOPY = 0x00CC0020; // BitBlt dwRop parameter
[DllImport("gdi32.dll")]
public static extern bool BitBlt(IntPtr hObject, int nXDest, int nYDest,
int nWidth, int nHeight, IntPtr hObjectSource,
int nXSrc, int nYSrc, int dwRop);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleBitmap(IntPtr hDC, int nWidth,
int nHeight);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleDC(IntPtr hDC);
[DllImport("gdi32.dll")]
public static extern bool DeleteDC(IntPtr hDC);
[DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);
[DllImport("gdi32.dll")]
public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);
}
/// <summary>
/// Helper class containing User32 API functions
/// </summary>
private class User32
{
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int left;
public int top;
public int right;
public int bottom;
}
[DllImport("user32.dll")]
public static extern IntPtr GetDesktopWindow();
[DllImport("user32.dll")]
public static extern IntPtr GetWindowDC(IntPtr hWnd);
[DllImport("user32.dll")]
public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);
[DllImport("user32.dll")]
public static extern IntPtr GetWindowRect(IntPtr hWnd, ref RECT rect);
[DllImport("user32.dll")]
public static extern bool GetWindowInfo(IntPtr hwnd, ref WINDOWINFO pwi);
[StructLayout(LayoutKind.Sequential)]
public struct WINDOWINFO
{
public uint cbSize;
public RECT rcWindow;
public RECT rcClient;
public uint dwStyle;
public uint dwExStyle;
public uint dwWindowStatus;
public uint cxWindowBorders;
public uint cyWindowBorders;
public ushort atomWindowType;
public ushort wCreatorVersion;
public WINDOWINFO(Boolean? filler)
: this() // Allows automatic initialization of "cbSize" with "new WINDOWINFO(null/true/false)".
{
cbSize = (UInt32)(Marshal.SizeOf(typeof(WINDOWINFO)));
}
}
}
}
}
To get the list of open windows I'm using following code.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using HWND = System.IntPtr;
/// <summary>Contains functionality to get all the open windows.</summary>
public static class OpenWindowGetter
{
/// <summary>Returns a dictionary that contains the handle and title of all the open windows.</summary>
/// <returns>A dictionary that contains the handle and title of all the open windows.</returns>
public static IDictionary<HWND, string> GetOpenWindows()
{
HWND shellWindow = GetShellWindow();
Dictionary<HWND, string> windows = new Dictionary<HWND, string>();
EnumWindows(delegate (HWND hWnd, int lParam)
{
if (hWnd == shellWindow) return true;
if (!IsWindowVisible(hWnd)) return true;
int length = GetWindowTextLength(hWnd);
if (length == 0) return true;
StringBuilder builder = new StringBuilder(length);
GetWindowText(hWnd, builder, length + 1);
windows[hWnd] = builder.ToString();
return true;
}, 0);
return windows;
}
private delegate bool EnumWindowsProc(HWND hWnd, int lParam);
[DllImport("USER32.DLL")]
private static extern bool EnumWindows(EnumWindowsProc enumFunc, int lParam);
[DllImport("USER32.DLL")]
private static extern int GetWindowText(HWND hWnd, StringBuilder lpString, int nMaxCount);
[DllImport("USER32.DLL")]
private static extern int GetWindowTextLength(HWND hWnd);
[DllImport("USER32.DLL")]
private static extern bool IsWindowVisible(HWND hWnd);
[DllImport("USER32.DLL")]
private static extern IntPtr GetShellWindow();
}
Following is the Main class
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using ScreenShotDemo;
using System.Drawing.Imaging;
namespace ScreenCaptureTest
{
class Program
{
static void Main(string[] args)
{
long start = DateTime.Now.Millisecond;
captureAllWindowsToFile();
//captureAllWindowsToFile2();
//captureDesktopToFile();
long end = DateTime.Now.Millisecond;
Console.WriteLine("time taken: " + (end - start));
//Console.Read();
}
static void captureAllWindowsToFile()
{
IDictionary<IntPtr, string> windowDict = OpenWindowGetter.GetOpenWindows();
ScreenCapture sc = new ScreenCapture();
int captureI = 0;
string message = "";
foreach(KeyValuePair<IntPtr, string> window in windowDict)
{
string imageName = "test" + ++captureI + ".jpg";
message +=imageName + " : " + window.Value + "\n";
sc.CaptureWindowToFile(window.Key, imageName, ImageFormat.Jpeg);
}
Console.WriteLine(message);
}
static void captureDesktopToFile()
{
ScreenCapture sc = new ScreenCapture();
sc.CaptureScreenToFile("current.jpg", ImageFormat.Jpeg);
}
}
}
Any help is appreciated.

I finally found the issue.
I had changed windows 7 settings for best performance, once I changed it to normal Aero settings. It works as expected.

WebBrowser.DrawToBitmap() or other methods?

I am trying to capture the content of the WebBrowser control. DrawToBitmap() would work perfectly, but it is not supported in documentation for the WebBrowser control. I have been trying to find another way to capture the contents of the WebBrowser control and save them to a local image file.
Does anyone have any workarounds or other methods to save the contents of the WebBrowser control to a local image file?

The Control.DrawToBitmap doesn't always work so I resorted to the following native API calls that provide more consistent results:
The Utilities class. Call Utilities.CaptureWindow(Control.Handle) to capture a specific control:
public static class Utilities
{
public static Image CaptureScreen()
{
return CaptureWindow(User32.GetDesktopWindow());
}
public static Image CaptureWindow(IntPtr handle)
{
IntPtr hdcSrc = User32.GetWindowDC(handle);
RECT windowRect = new RECT();
User32.GetWindowRect(handle, ref windowRect);
int width = windowRect.right - windowRect.left;
int height = windowRect.bottom - windowRect.top;
IntPtr hdcDest = Gdi32.CreateCompatibleDC(hdcSrc);
IntPtr hBitmap = Gdi32.CreateCompatibleBitmap(hdcSrc, width, height);
IntPtr hOld = Gdi32.SelectObject(hdcDest, hBitmap);
Gdi32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, ApiConstants.SRCCOPY);
Gdi32.SelectObject(hdcDest, hOld);
Gdi32.DeleteDC(hdcDest);
User32.ReleaseDC(handle, hdcSrc);
Image image = Image.FromHbitmap(hBitmap);
Gdi32.DeleteObject(hBitmap);
return image;
}
}
The Gdi32 class:
public class Gdi32
{
[DllImport("gdi32.dll")]
public static extern bool BitBlt(IntPtr hObject, int nXDest, int nYDest, int nWidth, int nHeight, IntPtr hObjectSource, int nXSrc, int nYSrc, int dwRop);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleBitmap(IntPtr hDC, int nWidth, int nHeight);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleDC(IntPtr hDC);
[DllImport("gdi32.dll")]
public static extern bool DeleteDC(IntPtr hDC);
[DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);
[DllImport("gdi32.dll")]
public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);
}
The User32 class:
public static class User32
{
[DllImport("user32.dll")]
public static extern IntPtr GetDesktopWindow();
[DllImport("user32.dll")]
public static extern IntPtr GetWindowDC(IntPtr hWnd);
[DllImport("user32.dll")]
public static extern IntPtr GetWindowRect(IntPtr hWnd, ref RECT rect);
[DllImport("user32.dll")]
public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);
}
The constants used:
public const int SRCCOPY = 13369376;
The structs used:
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int left;
public int top;
public int right;
public int bottom;
}
A friendly Control extension method:
public static class ControlExtensions
{
public static Image DrawToImage(this Control control)
{
return Utilities.CaptureWindow(control.Handle);
}
}
This is a code snippet from my CC.Utilities project and I specifically wrote it to take screenshots from the WebBrowser control.

The following method can capture the entire window image even if the window is larger than the size of screen. Then it can capture the image of the contents of the page if the window be resized to the webBrowser.Document.OffsetRectangle.Size
class NativeMethods
{
[ComImport]
[Guid("0000010D-0000-0000-C000-000000000046")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
interface IViewObject
{
void Draw([MarshalAs(UnmanagedType.U4)] uint dwAspect, int lindex, IntPtr pvAspect, [In] IntPtr ptd, IntPtr hdcTargetDev, IntPtr hdcDraw, [MarshalAs(UnmanagedType.Struct)] ref RECT lprcBounds, [In] IntPtr lprcWBounds, IntPtr pfnContinue, [MarshalAs(UnmanagedType.U4)] uint dwContinue);
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
struct RECT
{
public int Left;
public int Top;
public int Right;
public int Bottom;
}
public static void GetImage(object obj, Image destination, Color backgroundColor)
{
using(Graphics graphics = Graphics.FromImage(destination))
{
IntPtr deviceContextHandle = IntPtr.Zero;
RECT rectangle = new RECT();
rectangle.Right = destination.Width;
rectangle.Bottom = destination.Height;
graphics.Clear(backgroundColor);
try
{
deviceContextHandle = graphics.GetHdc();
IViewObject viewObject = obj as IViewObject;
viewObject.Draw(1, -1, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, deviceContextHandle, ref rectangle, IntPtr.Zero, IntPtr.Zero, 0);
}
finally
{
if(deviceContextHandle != IntPtr.Zero)
{
graphics.ReleaseHdc(deviceContextHandle);
}
}
}
}
}
Usage :
Bitmap screenshot = new Bitmap(1024, 768);
NativeMethods.GetImage(webBrowser.ActiveXInstance, screenshot, Color.White);

I am using DrawToBitmap (Visual Studio 2008 C#) to capture big images (user signed invoices,content out of the screen). Basically it is working well but I am getting blank images. About 100 employees are using this software, about every 2 weeks I can see one blank image.
I have done a lot of testing and one funny thing I found is:
I created a button to generate the image from the webbrowser. Usually is OK but if I click the webbrowser first, then click the create-button, the blank image will appear.

I used OleDraw method as in this topic on SO, but integrated it in a class derived from WebBrowser. This allows to do normal Control.DrawToBitmap not only for the WebBrowser, but for a form with WebBrowser in it as well. This also works if the form is hidden (covered by another form, including MDI parent form) and should work when user has locked session with Win+L (I haven't tested it).
public class WebBrowserEx : WebBrowser
{
private const uint DVASPECT_CONTENT = 1;
[DllImport("ole32.dll", PreserveSig = false)]
private static extern void OleDraw([MarshalAs(UnmanagedType.IUnknown)] object pUnk,
uint dwAspect,
IntPtr hdcDraw,
[In] ref System.Drawing.Rectangle lprcBounds
);
protected override void WndProc(ref Message m)
{
const int WM_PRINT = 0x0317;
switch (m.Msg)
{
case WM_PRINT:
Rectangle browserRect = new Rectangle(0, 0, this.Width, this.Height);
// Don't know why, but drawing with OleDraw directly on HDC from m.WParam.
// results in badly scaled (stretched) image of the browser.
// So, drawing to an intermediate bitmap first.
using (Bitmap browserBitmap = new Bitmap(browserRect.Width, browserRect.Height))
{
using (var graphics = Graphics.FromImage(browserBitmap))
{
var hdc = graphics.GetHdc();
OleDraw(this.ActiveXInstance, DVASPECT_CONTENT, hdc, ref browserRect);
graphics.ReleaseHdc(hdc);
}
using (var graphics = Graphics.FromHdc(m.WParam))
{
graphics.DrawImage(browserBitmap, Point.Empty);
}
}
// ignore default WndProc
return;
}
base.WndProc(ref m);
}
}

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

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?

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.

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);
}
}