如何從網絡攝像頭捕獲視頻？

Question

我需要從網絡攝像頭捕獲視頻。 C＃/ .NET中是否有任何類可以幫助我解決這個問題。 我只對實時數據感興趣。

是否有任何好的C＃/ .NET書籍我可以學習以獲得對語言和平台的深入了解？

Answer 1

這就是我使用的。 您需要第一個類來迭代您的設備：

public class DeviceManager
{
    [DllImport("avicap32.dll")]
    protected static extern bool capGetDriverDescriptionA(short wDriverIndex,
        [MarshalAs(UnmanagedType.VBByRefStr)]ref String lpszName,
       int cbName, [MarshalAs(UnmanagedType.VBByRefStr)] ref String lpszVer, int cbVer);

    static ArrayList devices = new ArrayList();

    public static TCamDevice[] GetAllDevices()
    {
        String dName = "".PadRight(100);
        String dVersion = "".PadRight(100);

        for (short i = 0; i < 10; i++)
        {
            if (capGetDriverDescriptionA(i, ref dName, 100, ref dVersion, 100))
            {
                TCamDevice d = new TCamDevice(i);
                d.Name = dName.Trim();
                d.Version = dVersion.Trim();

                devices.Add(d);
            }
        }

        return (TCamDevice[])devices.ToArray(typeof(TCamDevice));
    }

    public static TCamDevice GetDevice(int deviceIndex)
    {
        return (TCamDevice)devices[deviceIndex];
    }
}

和這一個控制凸輪。

public class TCamDevice
{
     private const short WM_CAP = 0x400;
    private const int WM_CAP_DRIVER_CONNECT = 0x40a;
    private const int WM_CAP_DRIVER_DISCONNECT = 0x40b;
    private const int WM_CAP_EDIT_COPY = 0x41e;
    private const int WM_CAP_SET_PREVIEW = 0x432;
    private const int WM_CAP_SET_OVERLAY = 0x433;
    private const int WM_CAP_SET_PREVIEWRATE = 0x434;
    private const int WM_CAP_SET_SCALE = 0x435;
    private const int WS_CHILD = 0x40000000;
    private const int WS_VISIBLE = 0x10000000;

    [DllImport("avicap32.dll")]
    protected static extern int capCreateCaptureWindowA([MarshalAs(UnmanagedType.VBByRefStr)] ref string lpszWindowName,
        int dwStyle, int x, int y, int nWidth, int nHeight, int hWndParent, int nID);

    [DllImport("user32", EntryPoint = "SendMessageA")]
    protected static extern int SendMessage(int hwnd, int wMsg, int wParam, [MarshalAs(UnmanagedType.AsAny)] object lParam);

    [DllImport("user32")]
    protected static extern int SetWindowPos(int hwnd, int hWndInsertAfter, int x, int y, int cx, int cy, int wFlags);

    [DllImport("user32")]
    protected static extern bool DestroyWindow(int hwnd);

    int index;
    int deviceHandle;

    public TCamDevice(int index)
    {
        this.index = index;
    }

    private string _name;

    public string Name
    {
        get { return _name; }
        set { _name = value; }
    }

    private string _version;

    public string Version
    {
        get { return _version; }
        set { _version = value; }
    }

    public override string ToString()
    {
        return this.Name;
    }
    /// <summary>
    /// To Initialize the device
    /// </summary>
    /// <param name="windowHeight">Height of the Window</param>
    /// <param name="windowWidth">Width of the Window</param>
    /// <param name="handle">The Control Handle to attach the device</param>
    public void Init(int windowHeight, int windowWidth, int handle)
    {
        string deviceIndex = Convert.ToString(this.index);
        deviceHandle = capCreateCaptureWindowA(ref deviceIndex, WS_VISIBLE | WS_CHILD, 0, 0, windowWidth, windowHeight, handle, 0);

        if (SendMessage(deviceHandle, WM_CAP_DRIVER_CONNECT, this.index, 0) > 0)
        {
            SendMessage(deviceHandle, WM_CAP_SET_SCALE, -1, 0);
            SendMessage(deviceHandle, WM_CAP_SET_PREVIEWRATE, 0x42, 0);
            SendMessage(deviceHandle, WM_CAP_SET_PREVIEW, -1, 0);

            SetWindowPos(deviceHandle, 1, 0, 0, windowWidth, windowHeight, 6);
        }
    }

    /// <summary>
    /// Shows the webcam preview in the control
    /// </summary>
    /// <param name="windowsControl">Control to attach the webcam preview</param>
    public void ShowWindow(global::System.Windows.Forms.Control windowsControl)
    {
        Init(windowsControl.Height, windowsControl.Width, windowsControl.Handle.ToInt32());                        
    }

    /// <summary>
    /// Stop the webcam and destroy the handle
    /// </summary>
    public void Stop()
    {
        SendMessage(deviceHandle, WM_CAP_DRIVER_DISCONNECT, this.index, 0);

        DestroyWindow(deviceHandle);
    }
}

ShowWindow將PictureBox作為參數。

Answer 2

我建議你使用第三方庫。 這將是最好的解決方案，而不是發明自己的自行車。 在這里，我使用了AForge.Net 。 雖然它在性能方面存在一些問題，但是當我的性能成為一個關鍵問題時，我自己調整了庫。 AForge.Net代碼是開源的，您可以根據自己的需要進行調整。

至於書籍，你絕對應該看看Jeffrey Richter的“CLR via C＃”和John Skeet的“C＃in Depth” 。

Answer 3

您可以使用Microsoft Expression Encoder 4 SP2 。 這是一個很棒的庫，您可以將其添加到項目中並獲取實時預覽，快照和視頻錄制 。 更多細節包括Massimo Conti的示例項目： 如何在C＃中使用帶有.NET Framework 4.0和Microsoft Expression Encoder 4的Web攝像頭

Answer 4

使用WebCam_Capture.dll捕獲照片和視頻。 這里是鏈接這里是源代碼對於LINK