在使用DirectShow桌面录制Fliped光标图标 [英] Fliped cursor icon on desktop recording using directshow

问题描述

使用Directshow.NET我已经开发了一个应用程序，它会记录桌面屏幕，来得到我们需要通过我们自己的画鼠标指针鼠标指针。所以我加了 SampleGrabber ADN在 BufferCB 我写了下面的代码：

Using Directshow.NET I have developed an application which will record the desktop screen, to get mouse pointer we need to paint mouse pointer by our own. So I added SampleGrabber adn in BufferCB I have written below code:

    public const Int32 CURSOR_SHOWING = 0x00000001;

    [StructLayout(LayoutKind.Sequential)]
    public struct ICONINFO
    {
        public bool fIcon;
        public Int32 xHotspot;
        public Int32 yHotspot;
        public IntPtr hbmMask;
        public IntPtr hbmColor;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct POINT
    {
        public Int32 x;
        public Int32 y;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct CURSORINFO
    {
        public Int32 cbSize;
        public Int32 flags;
        public IntPtr hCursor;
        public POINT ptScreenPos;
    }

    [DllImport("user32.dll")]
    public static extern bool GetCursorInfo(out CURSORINFO pci);

    [DllImport("user32.dll")]
    public static extern IntPtr CopyIcon(IntPtr hIcon);

    [DllImport("user32.dll")]
    public static extern bool DrawIcon(IntPtr hdc, int x, int y, IntPtr hIcon);

    [DllImport("user32.dll")]
    public static extern bool GetIconInfo(IntPtr hIcon, out ICONINFO piconinfo);

public int BufferCB(double SampleTime, IntPtr pBuffer, int BufferLen)
{
Graphics g;
Bitmap v;
v = new Bitmap(m_videoWidth, m_videoHeight, m_stride, System.Drawing.Imaging.PixelFormat.Format24bppRgb, pBuffer);            
g = Graphics.FromImage(v);
CURSORINFO cursorInfo;
cursorInfo.cbSize = Marshal.SizeOf(typeof(CURSORINFO));

if (GetCursorInfo(out cursorInfo))
{
    if (cursorInfo.flags == CURSOR_SHOWING)
    {
        var iconPointer = CopyIcon(cursorInfo.hCursor);
        ICONINFO iconInfo;
        int iconX, iconY;

        if (GetIconInfo(iconPointer, out iconInfo))
        {
            iconX = cursorInfo.ptScreenPos.x - ((int)iconInfo.xHotspot);
            iconY = cursorInfo.ptScreenPos.y - ((int)iconInfo.yHotspot);

            DrawIcon(g.GetHdc(), iconX, iconY, cursorInfo.hCursor);
            g.ReleaseHdc();
            g.Dispose();
            v.Dispose();                        
        }
    }
}
return 0;
}

此代码是画鼠标光标，但是光标翻转Y轴。

This code is painting the mouse cursor but cursor is flipped on Y axis.

这可能是因为 BufferCB 如果我们转换的pbuffer 中的位图，则该帧被翻转Y轴。后在 BufferCB ;为了解决这个我翻转Y轴当前帧加入 v.RotateFlip（RotateFlipType.RotateNoneFlipY）这种变化的鼠标指针是不是在桌面录制视频可见。

It's may be because in BufferCB if we convert pBuffer in Bitmap then that frame is flipped on Y axis. To solve this I flipped current frame on Y axis by adding v.RotateFlip(RotateFlipType.RotateNoneFlipY); inside BufferCB after this change mouse pointer is not visible in desktop recording video.

我怎么可以翻转鼠标指针？

How I can flip mouse pointer?

< STRONG>更新＃1

我转换图标指向图标然后到位图使用 Icon.ToBitmap（），然后翻转Y轴，这里是代码（感谢@Roman右）：

I converted icon pointer to Icon then into Bitmap using Icon.ToBitmap() and then flipped on Y axis, here is code (Thanks to @Roman R.):

...
iconX = cursorInfo.ptScreenPos.x - ((int)iconInfo.xHotspot);
iconY = cursorInfo.ptScreenPos.y - ((int)iconInfo.yHotspot);

Icon ic = Icon.FromHandle(iconPointer);
Bitmap icon = ic.ToBitmap();
icon.RotateFlip(RotateFlipType.RotateNoneFlipY);
g.DrawImage(icon, iconX, iconY);
g.Dispose();
v.Dispose();
icon.Dispose();
ic.Dispose();  
...

只有一个问题，我面对的上述修改，有时我得到的ArgumentException 在行位图图标= ic.ToBitmap（）;

  System.ArgumentException occurred
  HResult=-2147024809
  Message=Parameter is not valid.
  Source=System.Drawing
  StackTrace:
       at System.Drawing.Bitmap.FromHicon(IntPtr hicon)
  InnerException: 

我处理使用的所有位图，还是我得到这个例外。

I disposed all the bitmaps used, still i get this exception.

推荐答案

您这里的问题是你的 BufferCB 的实施。您创建一个临时图形 / 位图对象，这样就可以使用光标覆盖更新。你有这样的位图倒过来，并将其应用于翻转图标正常战平。

The problem you have here is your BufferCB implementation. You create a temporary Graphics/Bitmap object, so that it could be updated with the cursor overlay. You have this bitmap upside down and normal draw of the icon applies it flipped.

您需要考虑到，你会得到24位RGB缓冲的行正常秩序与 BufferCB 回调底部到顶部; 位图构造预期是相反的。您需要线转移到位图以相反的顺序，然后让他们回来分别。我不知道，如果负的步幅作品在那里很好，想必也不会。或仅仅叠加光标预翻转，以补偿翻转背景和叠加坐标太

You need to take into account that normal order of lines of 24-bit RGB buffer you get with BufferCB callback is bottom-to-top; order of lines Bitmap constructor expects is the opposite. You need to transfer lines into Bitmap in reversed order, then get them back respectively. I am not sure if negative stride works out there well, presumably it will not. Or simply overlay the cursor pre-flipped, to compensate for flipped background and overlay coordinates too.

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