WINCODEC_ERR_WIN32ERROR 0x88982F94 when calling IWICComponentFactory.CreateBitmapFromMemory - com

Question

I'm getting the following error when calling IWICComponentFactory.CreateBitmapFromMemory and passing it a pointer to Scan0 of a 32bppArgb GDI+ bitmap
WINCODEC_ERR_WIN32ERROR
0x88982F94
Windows Codecs received an error from the Win32 system.
IWICComponentFactory interface decl:
new IWICBitmap CreateBitmapFromMemory(
uint uiWidth,
uint uiHeight,
[MarshalAs(UnmanagedType.LPStruct)]
Guid pixelFormat,
uint cbStride,
uint cbBufferSize,
[MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 5)]
byte[] pbBuffer
);
new IWICBitmap CreateBitmapFromMemory(
uint uiWidth,
uint uiHeight,
[MarshalAs(UnmanagedType.LPStruct)]
Guid pixelFormat,
uint cbStride,
uint cbBufferSize,
IntPtr pbBuffer
);
Full code:
public static IWICBitmap ToWic(IWICComponentFactory factory, Bitmap bit) {
BitmapData bd = bit.LockBits(new Rectangle(0, 0, bit.Width, bit.Height),
ImageLockMode.ReadOnly, bit.PixelFormat);
IWICBitmap b = null;
try {
//Create WIC bitmap directly from unmanaged memory
b = factory.CreateBitmapFromMemory((uint)bit.Width, (uint)bit.Height,
ConversionUtils.FromPixelFormat(bit.PixelFormat), (uint)bd.Stride,
(uint)(bd.Stride * bd.Height), bd.Scan0);
return b;
} finally {
bit.UnlockBits(bd);
}
}
Width, Height, buffer size, format GUID, and scan size all seem correct. I can't figure out why this is happening (there are no google results for the error code or message

Answer 1

This isn't an answer as to why the original code doesn't work - but it's a workaround. Using IWICImagingFactory_CreateBitmapFromMemory_Proxy , everything works fine. But why didn't the original work as it's supposed to? And why the _Proxy methods with near-identical signatures?
[DllImport("WindowsCodecs.dll", EntryPoint = "IWICImagingFactory_CreateBitmapFromMemory_Proxy")]
internal static extern int CreateBitmapFromMemory(IWICComponentFactory factory, uint width, uint height, ref Guid pixelFormatGuid, uint stride, uint cbBufferSize, IntPtr pvPixels, out IWICBitmap ppIBitmap);
public static IWICBitmap ToWic(IWICComponentFactory factory, Bitmap bit) {
Guid pixelFormat = ConversionUtils.FromPixelFormat(bit.PixelFormat);
if (pixelFormat == Guid.Empty) throw new NotSupportedException("PixelFormat " + bit.PixelFormat.ToString() + " not supported.");
BitmapData bd = bit.LockBits(new Rectangle(0, 0, bit.Width, bit.Height), ImageLockMode.ReadOnly, bit.PixelFormat);
IWICBitmap b = null;
try {
//Create WIC bitmap directly from unmanaged memory
long result = CreateBitmapFromMemory(factory, (uint)bit.Width,
(uint)bit.Height, ref pixelFormat, (uint)bd.Stride,
(uint)(bd.Stride * bd.Height), bd.Scan0, out b);
if (result == 0x80070057) throw new ArgumentException();
if (result < 0) throw new Exception("HRESULT " + result);
return b;
} finally {
bit.UnlockBits(bd);
}
}
For reference, here is the COM method and here is the proxy method. Both use [IN] BYTE *pbBuffer.