C # Camera Programming

Camera programming

After installing the camera, you can usually find a Avicap32.dll file

This is a class about envisioning the head

using System;


using System.Runtime.InteropServices;


namespace Webcam


{


///

Summary description of the
///AVICap.


///


public class Showvideo


{


//Showvideo calls


[DllImport ("Avicap32.dll")] public static extern IntPtr Capcreatecapturewindowa (byte[] lpszwindowname, int dwstyle , int x, int y, int nwidth, int nheight, IntPtr hwndparent, int nID);


[DllImport ("Avicap32.dll")] public static extern bool Capgetdriverdescriptiona (short wdriver, byte[] lpszname, int c Bname, byte[] lpszver, int cbver);


[DllImport ("User32.dll")] public static extern bool SendMessage (IntPtr hWnd, int wmsg, bool wParam, int lParam);


[DllImport ("User32.dll")] public static extern bool SendMessage (IntPtr hWnd, int wmsg, short wParam, int lParam);


[DllImport ("User32.dll")] public static extern bool SendMessage (IntPtr hWnd, int wmsg, short wParam, Frameeventhandl Er lParam);


[DllImport ("User32.dll")] public static extern bool SendMessage (IntPtr hWnd, int wmsg, int wParam, ref bitmapinfo LP Aram);


[DllImport ("User32.dll")] public static extern int SetWindowPos (IntPtr hWnd, int hwndinsertafter, int x, int y, int CX, int cy, int wflags);


[DllImport ("Avicap32.dll")]public static extern int Capgetvideoformat (IntPtr hWnd, IntPtr psvideoformat, int wsize) ;


//Constants


Public const int wm_user = 0x400;


Public const int ws_child = 0x40000000;


Public const int ws_visible = 0x10000000;


Public const int swp_nomove = 0x2;


Public const int swp_nozorder = 0x4;


Public const int wm_cap_driver_connect = Wm_user 10;


public const int wm_cap_driver_disconnect = Wm_user 11;


Public const int wm_cap_set_callback_frame = Wm_user 5;


Public const int wm_cap_set_preview = Wm_user 50;


Public const int wm_cap_set_previewrate = Wm_user 52;


Public const int wm_cap_set_videoformat = Wm_user 45;





//Structures


[StructLayout (layoutkind.sequential)] public struct VIDEOHDR


{


[MarshalAs (UNMANAGEDTYPE.I4)] public int lpdata;


[MarshalAs (UNMANAGEDTYPE.I4)] public int dwbufferlength;


[MarshalAs (UNMANAGEDTYPE.I4)] public int dwbytesused;


[MarshalAs (UNMANAGEDTYPE.I4)] public int dwtimecaptured;


[MarshalAs (UNMANAGEDTYPE.I4)] public int dwuser;


[MarshalAs (UNMANAGEDTYPE.I4)] public int dwflags;


[MarshalAs (UnmanagedType.ByValArray, sizeconst=4)] public int[] dwreserved;


}


[StructLayout (layoutkind.sequential)] public struct Bitmapinfoheader


{


[MarshalAs (UNMANAGEDTYPE.I4)] public Int32 bisize;


[MarshalAs (UNMANAGEDTYPE.I4)] public Int32 biwidth;


[MarshalAs (UNMANAGEDTYPE.I4)] public Int32 biheight;


[MarshalAs (UNMANAGEDTYPE.I2)] public short biplanes;


[MarshalAs (UNMANAGEDTYPE.I2)] public short bibitcount;


[MarshalAs (UNMANAGEDTYPE.I4)] public Int32 bicompression;


[MarshalAs (UNMANAGEDTYPE.I4)] public Int32 bisizeimage;


[MarshalAs (UNMANAGEDTYPE.I4)] public Int32 bixpelspermeter;


[MarshalAs (UNMANAGEDTYPE.I4)] public Int32 biypelspermeter;


[MarshalAs (UNMANAGEDTYPE.I4)] public Int32 biclrused;


[MarshalAs (UNMANAGEDTYPE.I4)] public Int32 biclrimportant;


}


[StructLayout (layoutkind.sequential)] public struct bitmapinfo


{


[MarshalAs (Unmanagedtype.struct, sizeconst=40)] public bitmapinfoheader bmiheader;


[MarshalAs (UnmanagedType.ByValArray, sizeconst=1024)] public int32[] bmicolors;


}





public delegate void Frameeventhandler (IntPtr lwnd, IntPtr LPVHDR);





//Public methods


public static Object Getstructure (INTPTR ptr,valuetype structure)


{


return Marshal.PtrToStructure (ptr,structure. GetType ());


}





public static object Getstructure (int ptr,valuetype structure)


{


return Getstructure (New IntPtr (PTR), structure);


}





public static void Copy (INTPTR ptr,byte[] data)


{


marshal.copy (Ptr,data,0,data. Length);


}





public static void Copy (int ptr,byte[] data)


{


Copy (New IntPtr (PTR), data);


}





public static int SizeOf (object structure)


{


return marshal.sizeof (structure);


}


}


//web Camera Class


public class Webcamera


{


//Constructur


public Webcamera (IntPtr handle, int width,int height)


{


mcontrolptr = handle;


mwidth = width;


mheight = height;


}





//Delegate for frame callback


public delegate void Recievedframeeventhandler (byte[] data);


public event Recievedframeeventhandler Recievedframe;





private IntPtr LWNDC; Holds the unmanaged handle of the control


private IntPtr mcontrolptr; Holds the managed pointer of the control


private int mwidth;


private int mheight;





private Showvideo.frameeventhandler Mframeeventhandler;　Delegate instance for the frame Callback-must keep alive! GC should not collect it





//Close the Web camera


public void Closewebcam ()


{


This.capdriverdisconnect (THIS.LWNDC);


}





//Start the Web camera


public void Startwebcam ()


{


byte[] lpszname = new byte[100];


byte[] Lpszver = new byte[100];





Showvideo.capgetdriverdescriptiona (0, Lpszname, 100,lpszver, 100);


THIS.LWNDC = Showvideo.capcreatecapturewindowa (lpszname, showvideo.ws_visible showVideo.WS_CHILD, 0, 0, MWidth, MH Eight, mcontrolptr, 0);





if (this.capdriverconnect (THIS.LWNDC, 0))


{


this.cappreviewrate (THIS.LWNDC, 66);


This.cappreview (THIS.LWNDC, true);


showvideo.bitmapinfo bitmapinfo = new Showvideo.bitmapinfo ();


bitmapinfo.bmiHeader.biSize = showvideo.sizeof (Bitmapinfo.bmiheader);


bitmapinfo.bmiHeader.biWidth = 352;


bitmapinfo.bmiHeader.biHeight = 288;


bitmapinfo.bmiHeader.biPlanes = 1;


Bitmapinfo.bmiHeader.biBitCount = 24;


This.capsetvideoformat (THIS.LWNDC, ref bitmapinfo, Showvideo.sizeof (bitmapinfo));


This.mframeeventhandler = new Showvideo.frameeventhandler (framecallback);


this.capsetcallbackonframe (THIS.LWNDC, This.mframeeventhandler);


Showvideo.setwindowpos (THIS.LWNDC, 0, 0, 0, Mwidth, mheight, 6);


}


}


//Private Functions


private bool Capdriverconnect (IntPtr Lwnd, short i)


{


Return Showvideo.sendmessage (Lwnd, Showvideo.wm_cap_driver_connect, I, 0);


}


private bool Capdriverdisconnect (IntPtr lwnd)


{


return Showvideo.sendmessage (Lwnd, showvideo.wm_cap_driver_disconnect, 0, 0);


}





private bool Cappreview (INTPTR Lwnd, bool f)


{


return Showvideo.sendmessage (Lwnd, Showvideo.wm_cap_set_preview, F, 0);


}


private bool Cappreviewrate (IntPtr lwnd, short wms)


{


return Showvideo.sendmessage (Lwnd, showvideo.wm_cap_set_previewrate, WMS, 0);


}





private bool Capsetcallbackonframe (IntPtr Lwnd, Showvideo.frameeventhandler lpproc)


{　


return Showvideo.sendmessage (Lwnd, showvideo.wm_cap_set_callback_frame, 0, Lpproc);


}


private bool Capsetvideoformat (IntPtr hcapwnd, ref showvideo.bitmapinfo Bmpformat, int capformatsize)


{


return Showvideo.sendmessage (Hcapwnd, Showvideo.wm_cap_set_videoformat, capformatsize, ref BmpFormat);


}


private void Framecallback (IntPtr lwnd, IntPtr lpvhdr)


{


SHOWVIDEO.VIDEOHDR videoheader = new Showvideo.videohdr ();


byte[] Videodata;


Videoheader = (SHOWVIDEO.VIDEOHDR) showvideo.getstructure (Lpvhdr,videoheader);


videodata = new byte[videoheader.dwbytesused];


showvideo.copy (Videoheader.lpdata, videodata);


if (this. Recievedframe!= null)


this. Recievedframe (Videodata);


}


}


}