C#摄像头操作辅助类

/// <summary>
/// 摄像头操作辅助类，包括开启、关闭、抓图、设置等功能
/// </summary>
public class Camera
{
private IntPtr lwndC;
private IntPtr mControlPtr;
private int mWidth;
private int mHeight;

// 构造函数
public Camera(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 AviCapture.FrameEventHandler mFrameEventHandler;

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

/// <summary>
/// 开启摄像头
/// </summary>
public void StartWebCam()
{
byte[] lpszName = new byte[100];
byte[] lpszVer = new byte[100];

AviCapture.capGetDriverDescriptionA(1, lpszName, 100, lpszVer, 100);
this.lwndC = AviCapture.capCreateCaptureWindowA(lpszName, AviCapture.WS_VISIBLE + AviCapture.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);
AviCapture.BITMAPINFO bitmapinfo = new AviCapture.BITMAPINFO();
bitmapinfo.bmiHeader.biSize = AviCapture.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, AviCapture.SizeOf(bitmapinfo));

this.mFrameEventHandler = new AviCapture.FrameEventHandler(FrameCallBack);
this.capSetCallbackOnFrame(this.lwndC, this.mFrameEventHandler);
AviCapture.SetWindowPos(this.lwndC, 0, 0, 0, mWidth, mHeight, 6);
}
}

/// <summary>
/// 抓图到文件
/// </summary>
/// <param name="path"></param>
public void GrabImage(string path)
{
IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);
AviCapture.SendMessage(lwndC, AviCapture.WM_CAP_SAVEDIB, 0, hBmp.ToInt32());
}

/// <summary>
/// 抓图到剪切板
/// </summary>
/// <returns></returns>
public bool GrabImageToClipBoard()
{
return AviCapture.SendMessage(lwndC, AviCapture.WM_CAP_EDIT_COPY, 0, 0);
}

/// <summary>
/// 弹出色彩设置对话框
/// </summary>
public void SetCaptureSource()
{
AviCapture.CAPDRIVERCAPS caps = new AviCapture.CAPDRIVERCAPS();
AviCapture.SendMessage(lwndC, AviCapture.WM_CAP_GET_CAPS, AviCapture.SizeOf(caps), ref caps);
if (caps.fHasDlgVideoSource)
{
AviCapture.SendMessage(lwndC, AviCapture.WM_CAP_DLG_VIDEOSOURCE, 0, 0);
}
}

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

#region 以下为私有函数
private bool capDriverConnect(IntPtr lwnd, short i)
{
return AviCapture.SendMessage(lwnd, AviCapture.WM_CAP_DRIVER_CONNECT, i, 0);
}

private bool capDriverDisconnect(IntPtr lwnd)
{
return AviCapture.SendMessage(lwnd, AviCapture.WM_CAP_DRIVER_DISCONNECT, 0, 0);
}

private bool capPreview(IntPtr lwnd, bool f)
{
return AviCapture.SendMessage(lwnd, AviCapture.WM_CAP_SET_PREVIEW, f, 0);
}

private bool capPreviewRate(IntPtr lwnd, short wMS)
{
return AviCapture.SendMessage(lwnd, AviCapture.WM_CAP_SET_PREVIEWRATE, wMS, 0);
}

private bool capSetCallbackOnFrame(IntPtr lwnd, AviCapture.FrameEventHandler lpProc)
{
return AviCapture.SendMessage(lwnd, AviCapture.WM_CAP_SET_CALLBACK_FRAME, 0, lpProc);
}

private bool capSetVideoFormat(IntPtr hCapWnd, ref AviCapture.BITMAPINFO BmpFormat, int CapFormatSize)
{
return AviCapture.SendMessage(hCapWnd, AviCapture.WM_CAP_SET_VIDEOFORMAT, CapFormatSize, ref BmpFormat);
}

private void FrameCallBack(IntPtr lwnd, IntPtr lpVHdr)
{
AviCapture.VIDEOHDR videoHeader = new AviCapture.VIDEOHDR();
byte[] VideoData;
videoHeader = (AviCapture.VIDEOHDR)AviCapture.GetStructure(lpVHdr, videoHeader);
VideoData = new byte[videoHeader.dwBytesUsed];
AviCapture.Copy(videoHeader.lpData, VideoData);
if (this.RecievedFrame != null)
this.RecievedFrame(VideoData);
}
private bool capOverlay(IntPtr lwnd, bool f)
{
return AviCapture.SendMessage(lwnd, AviCapture.WM_CAP_SET_OVERLAY, f, 0);
}
#endregion

}

/// <summary>
/// 视频辅助类
/// </summary>
internal class AviCapture
{
//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);
}
}