WIC factory will always be nullptr on windows7 (used "What's a Creel?" tutorial)

Question

I used this tutorial and i always got an error that says "wicFactory was nullptr". I'm using windows 7 and this code doesn't make it work. I've read that you should use CLSID_WICImagingfactory1 But it doesn't work. this is my code:

HRESULT hr;
bmp = nullptr;

IWICBitmapDecoder *pDecoder = NULL;
IWICBitmapFrameDecode *pSource = NULL;
IWICFormatConverter *pConverter = NULL;

//Creating a factory
IWICImagingFactory *wicFactory = NULL;
CoCreateInstance(
    CLSID_WICImagingFactory1,
    NULL,
    CLSCTX_INPROC_SERVER,
    IID_IWICImagingFactory,
    (LPVOID*)&wicFactory);

MessageBox(NULL, (LPCWSTR)wicFactory, NULL, MB_OK);

//Creating a decoder

hr = wicFactory->CreateDecoderFromFilename(
    filename,
    NULL,
    GENERIC_READ,
    WICDecodeMetadataCacheOnLoad,
    &pDecoder);

//Read Frame from image
if (SUCCEEDED(hr)) {
    // Create the initial frame.
    hr = pDecoder->GetFrame(0, &pSource);
}

//Creating a Converter
if (SUCCEEDED(hr)) {

    // Convert the image format to 32bppPBGRA
    // (DXGI_FORMAT_B8G8R8A8_UNORM + D2D1_ALPHA_MODE_PREMULTIPLIED).
    hr = wicFactory->CreateFormatConverter(&pConverter);
}

//Setup the converter
if (SUCCEEDED(hr)) {
    hr = pConverter->Initialize(
        pSource,
        GUID_WICPixelFormat32bppPBGRA,
        WICBitmapDitherTypeNone,
        NULL,
        0.0f,
        WICBitmapPaletteTypeMedianCut
    );
}
//Use the converter to create an D2D1Bitmap
//ID2D1Bitmap* bmp;
if (SUCCEEDED(hr))
{
    hr = d2dg->pRT->CreateBitmapFromWicBitmap(
        pConverter,
        NULL,
        &bmp
    );
}

if (wicFactory)wicFactory->Release();
if (pDecoder)pDecoder->Release();
if (pConverter)pConverter->Release();
if (pSource)pSource->Release();

Can anyone Identify the issue here? I cant find any more information about that problem other then define _WIN32_WINNT to 0x0600 or 0x0601, still that wont help...

Yes, just remember, you should call CoInitializeEx before creating any COM object. — xeco, Nov 25 '19 at 20:20
@xeco seems like the issue is still there and still doesn't work — Itay, Nov 25 '19 at 20:54
You should check what HRESULT code `CreateDecoderFromFilename` returns. — xeco, Nov 26 '19 at 00:33
I've checked the hr of the WicFactory creation and its still messed up. gives an hr error. — Itay, Nov 26 '19 at 05:03

Chuck Walbourn · Answer 1 · 2020-01-17T19:59:47.760

As noted in the comments, you need to call CoInitializeEx before you can call CoCreateInstance.

BTW, here's some robust code for creating a WIC factory that handles the "WIC2" vs. "WIC1" down-level scenario for Windows 7 with or without the KB2670838 update:

namespace
{
    bool g_WIC2 = false;

    BOOL WINAPI InitializeWICFactory(PINIT_ONCE, PVOID, PVOID *ifactory) noexcept
    {
    #if (_WIN32_WINNT >= _WIN32_WINNT_WIN8) || defined(_WIN7_PLATFORM_UPDATE)
        HRESULT hr = CoCreateInstance(
            CLSID_WICImagingFactory2,
            nullptr,
            CLSCTX_INPROC_SERVER,
            __uuidof(IWICImagingFactory2),
            ifactory
        );

        if (SUCCEEDED(hr))
        {
            // WIC2 is available on Windows 10, Windows 8.x, and Windows 7 SP1 with KB 2670838 installed
            g_WIC2 = true;
            return TRUE;
        }
        else
        {
            g_WIC2 = false;

            hr = CoCreateInstance(
                CLSID_WICImagingFactory1,
                nullptr,
                CLSCTX_INPROC_SERVER,
                __uuidof(IWICImagingFactory),
                ifactory
            );
            return SUCCEEDED(hr) ? TRUE : FALSE;
        }
    #else
        g_WIC2 = false;

        return SUCCEEDED(CoCreateInstance(
            CLSID_WICImagingFactory,
            nullptr,
            CLSCTX_INPROC_SERVER,
            __uuidof(IWICImagingFactory),
            ifactory)) ? TRUE : FALSE;
    #endif
    }
}

IWICImagingFactory* GetWICFactory(bool& iswic2) noexcept
{
    static INIT_ONCE s_initOnce = INIT_ONCE_STATIC_INIT;

    IWICImagingFactory* factory = nullptr;
    if (!InitOnceExecuteOnce(&s_initOnce,
        InitializeWICFactory,
        nullptr,
        reinterpret_cast<LPVOID*>(&factory)))
    {
        return nullptr;
    }

    iswic2 = g_WIC2;
    return factory;
}

For details on what's in WIC2, see Microsoft Docs. I support both in DirectXTex to get 32bpp BMP with alpha (BITMAPV5HEADER) and support for 96bp TIFF (GUID_WICPixelFormat96bppRGBFloat) when WIC2 is installed.

You can use WIC2 on Windows 7 if installed, which you enable by building with /D_WIN32_WINNT=0x0601 /D_WIN7_PLATFORM_UPDATE.

WIC factory will always be nullptr on windows7 (used "What's a Creel?" tutorial)

1 Answers1