C#视频头操作

底层操作类：

using System;   
using System.Runtime.InteropServices;

namespace GetPhoto   
{   
     /// <summary>   
     /// AviCapture 的摘要说明。   
     /// </summary>   
     public class showVideo   
     {   
         //通过调用acicap32.dll进行读取摄像头数据   
         [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 cbName, 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, FrameEventHandler lParam);   
         [DllImport("User32.dll")]   
         public static extern bool SendMessage(IntPtr hWnd, int wMsg, int wParam, ref BITMAPINFO lParam);   
         [DllImport("User32.dll")]   
         public static extern bool SendMessage(IntPtr hWnd, int wMsg, int wParam, ref CAPDRIVERCAPS lParam);   
         [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);   
  
         //部分常量   
         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;   
         public const int WM_CAP_SAVEDIB = WM_USER + 25;   
         public const int WM_CAP_SET_OVERLAY = WM_USER + 51;   
         public const int WM_CAP_GET_CAPS = WM_USER + 14;   
         public const int WM_CAP_DLG_VIDEOFORMAT = WM_USER + 41;   
         public const int WM_CAP_DLG_VIDEOSOURCE = WM_USER + 42;   
         public const int WM_CAP_DLG_VIDEODISPLAY = WM_USER + 43;   
         public const int WM_CAP_EDIT_COPY = WM_USER + 30;   
         public const int WM_CAP_SET_SEQUENCE_SETUP = WM_USER + 64;   
         public const int WM_CAP_GET_SEQUENCE_SETUP = WM_USER + 65;   
  
  
         // 结构   
         [StructLayout(LayoutKind.Sequential)]   
         //VideoHdr   
         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)]   
         //BitmapInfoHeader   
         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)]   
         //BitmapInfo   
         public struct BITMAPINFO   
         {   
             [MarshalAs(UnmanagedType.Struct, SizeConst = 40)]   
             public BITMAPINFOHEADER bmiHeader;   
             [MarshalAs(UnmanagedType.ByValArray, SizeConst = 1024)]   
             public Int32[] bmiColors;   
         }   
  
         [StructLayout(LayoutKind.Sequential)]   
         public struct CAPDRIVERCAPS   
         {   
             [MarshalAs(UnmanagedType.U2)]   
             public UInt16 wDeviceIndex;   
             [MarshalAs(UnmanagedType.Bool)]   
             public bool fHasOverlay;   
             [MarshalAs(UnmanagedType.Bool)]   
             public bool fHasDlgVideoSource;   
             [MarshalAs(UnmanagedType.Bool)]   
             public bool fHasDlgVideoFormat;   
             [MarshalAs(UnmanagedType.Bool)]   
             public bool fHasDlgVideoDisplay;   
             [MarshalAs(UnmanagedType.Bool)]   
             public bool fCaptureInitialized;   
             [MarshalAs(UnmanagedType.Bool)]   
             public bool fDriverSuppliesPalettes;   
             [MarshalAs(UnmanagedType.I4)]   
             public int hVideoIn;   
             [MarshalAs(UnmanagedType.I4)]   
             public int hVideoOut;   
             [MarshalAs(UnmanagedType.I4)]   
             public int hVideoExtIn;   
             [MarshalAs(UnmanagedType.I4)]   
             public int hVideoExtOut;   
         }   
  
           
         public delegate void FrameEventHandler(IntPtr lwnd, IntPtr lpVHdr);   
  
         // 公共函数   
         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);   
         }   
     }   
}   

功能操作类：

using System;
using System.Runtime.InteropServices;

namespace GetPhoto
{
     /// <summary>   
     /// Camera 的摘要说明。   
     /// </summary>   

     public class WebCamera
     {
         private IntPtr lwndC;
         private IntPtr mControlPtr;
         private int mWidth;
         private int mHeight;

         // 构造函数   
         public WebCamera(IntPtr handle, int width, int height)
         {
             mControlPtr = handle;
             mWidth = width;
             mHeight = height;
         }

         // 帧回调的委托   
         public delegate void RecievedFrameEventHandler(byte[] data);
         public event RecievedFrameEventHandler RecievedFrame;
         private showVideo.FrameEventHandler mFrameEventHandler;

         // 关闭摄像头   
         public void CloseWebcam()
         {
             this.capDriverDisconnect(this.lwndC);
         }

         // 开启摄像头   
         public bool StartWebCam()
         {
             byte[] lpszName = new byte[100];
             byte[] lpszVer = new byte[100];
             try
             {
                 showVideo.capGetDriverDescriptionA(0, lpszName, 100, lpszVer, 100);
                 this.lwndC = showVideo.capCreateCaptureWindowA(lpszName, showVideo.WS_VISIBLE + showVideo.WS_CHILD, 0, 0, mWidth, mHeight, mControlPtr, 0);

                 if (this.capDriverConnect(this.lwndC, 0))
                 {
                     this.capPreviewRate(this.lwndC, 66);

                     this.capPreview(this.lwndC, true);
                     this.capOverlay(this.lwndC, true);
                     showVideo.BITMAPINFO bitmapinfo = new showVideo.BITMAPINFO();
                     bitmapinfo.bmiHeader.biSize = showVideo.SizeOf(bitmapinfo.bmiHeader);
                     bitmapinfo.bmiHeader.biWidth = this.mWidth;
                     bitmapinfo.bmiHeader.biHeight = this.mHeight;
                     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);
                     return true;
                 }
                 else
                 {
                     return false;
                 }
             }
             catch
             {
                 return false;
             }
         }

         public void grabImage(string path)      //抓图到文件   
         {
             IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);
             showVideo.SendMessage(lwndC, showVideo.WM_CAP_SAVEDIB, 0, hBmp.ToInt32());
         }
         public void setCaptureSource()           //弹出色彩设置对话框   
         {
             showVideo.CAPDRIVERCAPS caps = new showVideo.CAPDRIVERCAPS();
             showVideo.SendMessage(lwndC, showVideo.WM_CAP_GET_CAPS, showVideo.SizeOf(caps), ref   caps);
             if (caps.fHasDlgVideoSource)
             {
                 showVideo.SendMessage(lwndC, showVideo.WM_CAP_DLG_VIDEOSOURCE, 0, 0);

             }
         }
         public void setCaptureFormat()          //弹出视频格式设置对话框   
         {
             showVideo.CAPDRIVERCAPS caps = new showVideo.CAPDRIVERCAPS();
             showVideo.SendMessage(lwndC, showVideo.WM_CAP_GET_CAPS, showVideo.SizeOf(caps), ref   caps);
             if (caps.fHasDlgVideoSource)
             {
                 showVideo.SendMessage(lwndC, showVideo.WM_CAP_DLG_VIDEOFORMAT, 0, 0);

             }
         }
         public bool copyToClipBoard()            //抓图到剪切板   
         {
             return showVideo.SendMessage(lwndC, showVideo.WM_CAP_EDIT_COPY, 0, 0);
         }

         // 以下为私有函数   
         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);
         }
         private bool capOverlay(IntPtr lwnd, bool f)
         {
             return showVideo.SendMessage(lwnd, showVideo.WM_CAP_SET_OVERLAY, f, 0);
         }

     }
}