// Get next video frame
public Bitmap GetNextFrame()
{
// get frame at specified position
IntPtr pdib = Win32.AVIStreamGetFrame(getFrame, position);
if (pdib == IntPtr.Zero)
{
throw new ApplicationException("Failed getting frame");
}
Win32.BITMAPINFOHEADER bih;
// copy BITMAPINFOHEADER from unmanaged memory
bih = (Win32.BITMAPINFOHEADER)Marshal.PtrToStructure(pdib, typeof(Win32.BITMAPINFOHEADER));
// create new bitmap
Bitmap bmp = new Bitmap(width, height, PixelFormat.Format24bppRgb);
// lock bitmap data
BitmapData bmData = bmp.LockBits(
new Rectangle(0, 0, width, height),
ImageLockMode.ReadWrite,
PixelFormat.Format24bppRgb);
// copy image data
int srcStride = bmData.Stride; // width * 3;
int dstStride = bmData.Stride;
// check image direction
if (bih.biHeight > 0)
{
// it`s a bottom-top image
int dst = bmData.Scan0.ToInt32() + dstStride * (height - 1);
int src = pdib.ToInt32() + Marshal.SizeOf(typeof(Win32.BITMAPINFOHEADER));
for (int y = 0; y < height; y++)
{
Win32.memcpy(dst, src, srcStride);
dst -= dstStride;
src += srcStride;
}
}
else
{
// it`s a top bootom image
int dst = bmData.Scan0.ToInt32();
int src = pdib.ToInt32() + Marshal.SizeOf(typeof(Win32.BITMAPINFOHEADER));
if (srcStride != dstStride)
{
// copy line by line
for (int y = 0; y < height; y++)
{
Win32.memcpy(dst, src, srcStride);
dst += dstStride;
src += srcStride;
}
}
else
{
// copy the whole image
Win32.memcpy(dst, src, srcStride * height);
}
}
// unlock bitmap data
bmp.UnlockBits(bmData);
position++;
return(bmp);
}
