private void TestBitmapInfoHeader()
{
BitmapInfoHeader w1 = new BitmapInfoHeader();
FillBMI(w1, 0);
IntPtr ip = w1.GetPtr();
BitmapInfoHeader w2 = BitmapInfoHeader.PtrToBMI(ip);
Marshal.FreeCoTaskMem(ip);
}
private void FillBMI(BitmapInfoHeader w1, int iOffset)
{
w1.Size = Marshal.SizeOf(typeof(BitmapInfoHeader));
w1.ClrUsed = 0;
w1.BitCount = 32;
w1.Compression = 0;
w1.ClrImportant = 1 + iOffset;
w1.Height = 2 + iOffset;
w1.Planes = (short)(3 + iOffset);
w1.ImageSize = 4 + iOffset;
w1.Width = 5 + iOffset;
w1.XPelsPerMeter = 6 + iOffset;
w1.YPelsPerMeter = 7 + iOffset;
}
void TestGetCurrentImage()
{
BitmapInfoHeader bmh = new BitmapInfoHeader();
int i;
long l = 0;
IntPtr ip = IntPtr.Zero;
bmh.Size = Marshal.SizeOf(typeof(BitmapInfoHeader));
try
{
// Works in BasicPlayer
int hr = m_vdc.GetCurrentImage(bmh, out ip, out i, out l);
MFError.ThrowExceptionForHR(hr);
}
catch { }
}
public void CleanUpManagedData(object ManagedObj)
{
m_bmi = null;
}
public IntPtr MarshalManagedToNative(object managedObj)
{
m_bmi = managedObj as BitmapInfoHeader;
IntPtr ip = m_bmi.GetPtr();
return ip;
}
public void CopyFrom(BitmapInfoHeader bmi)
{
Size = bmi.Size;
Width = bmi.Width;
Height = bmi.Height;
Planes = bmi.Planes;
BitCount = bmi.BitCount;
Compression = bmi.Compression;
ImageSize = bmi.ImageSize;
YPelsPerMeter = bmi.YPelsPerMeter;
ClrUsed = bmi.ClrUsed;
ClrImportant = bmi.ClrImportant;
if (bmi is BitmapInfoHeaderWithData)
{
BitmapInfoHeaderWithData ext = this as BitmapInfoHeaderWithData;
BitmapInfoHeaderWithData ext2 = bmi as BitmapInfoHeaderWithData;
ext.bmiColors = new int[ext2.bmiColors.Length];
ext2.bmiColors.CopyTo(ext.bmiColors, 0);
}
}
public static BitmapInfoHeader PtrToBMI(IntPtr pNativeData)
{
int iEntries;
int biCompression;
int biClrUsed;
int biBitCount;
biBitCount = Marshal.ReadInt16(pNativeData, 14);
biCompression = Marshal.ReadInt32(pNativeData, 16);
biClrUsed = Marshal.ReadInt32(pNativeData, 32);
if (biCompression == 3) // BI_BITFIELDS
{
iEntries = 3;
}
else if (biClrUsed > 0)
{
iEntries = biClrUsed;
}
else if (biBitCount <= 8)
{
iEntries = 1 << biBitCount;
}
else
{
iEntries = 0;
}
BitmapInfoHeader bmi;
if (iEntries == 0)
{
// Create a simple BitmapInfoHeader struct
bmi = new BitmapInfoHeader();
Marshal.PtrToStructure(pNativeData, bmi);
}
else
{
BitmapInfoHeaderWithData ext = new BitmapInfoHeaderWithData();
ext.Size = Marshal.ReadInt32(pNativeData, 0);
ext.Width = Marshal.ReadInt32(pNativeData, 4);
ext.Height = Marshal.ReadInt32(pNativeData, 8);
ext.Planes = Marshal.ReadInt16(pNativeData, 12);
ext.BitCount = Marshal.ReadInt16(pNativeData, 14);
ext.Compression = Marshal.ReadInt32(pNativeData, 16);
ext.ImageSize = Marshal.ReadInt32(pNativeData, 20);
ext.XPelsPerMeter = Marshal.ReadInt32(pNativeData, 24);
ext.YPelsPerMeter = Marshal.ReadInt32(pNativeData, 28);
ext.ClrUsed = Marshal.ReadInt32(pNativeData, 32);
ext.ClrImportant = Marshal.ReadInt32(pNativeData, 36);
bmi = ext as BitmapInfoHeader;
ext.bmiColors = new int[iEntries];
IntPtr ip2 = new IntPtr(pNativeData.ToInt64() + Marshal.SizeOf(typeof(BitmapInfoHeader)));
Marshal.Copy(ip2, ext.bmiColors, 0, iEntries);
}
return bmi;
}
private void menuItem8_Click(object sender, EventArgs e)
{
MediaFoundation.Misc.BitmapInfoHeader pBih = new MediaFoundation.Misc.BitmapInfoHeader();
IntPtr pDib = IntPtr.Zero;
int pcbDib = 0;
long pTimeStamp = 0;
try
{
pBih.Size = Marshal.SizeOf(pBih);
int hr = evrDisplay.GetCurrentImage(pBih, out pDib, out pcbDib, out pTimeStamp);
DsError.ThrowExceptionForHR(hr);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK);
}
finally
{
if (pDib != IntPtr.Zero)
Marshal.FreeCoTaskMem(pDib);
}
}
