Add support for multiple GPUs on Windows

If the primary GPU is not an Intel GPU, libvpl cannot detect the
Intel GPU in the Windows environment, even though it is present.
The situation is, for example, using an NVIDIA graphics card with
an Intel CPU that has an embedded GPU. This patch allows the Intel
GPU to be detected in such situations.

Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>

Author: tyan0

libvpl/src/windows/mfx_library_iterator.cpp

@@ -619,9 +619,12 @@ mfxStatus MFXLibraryIterator::GetRegkeyDir(std::wstring &regDir, size_t length,
     mfxStatus sts = MFX_ERR_UNSUPPORTED;
     MFX::MFXLibraryIterator libIterator;
     wchar_t wRegDir[MFX_MAX_DLL_PATH];
+    int adapterNum = 0;
 
-    regDir.clear();
-    sts = libIterator.Init(MFX_LIB_HARDWARE, MFX_IMPL_VIA_D3D11, 0, storageID);
+    do {
+        sts = libIterator.Init(MFX_LIB_HARDWARE, MFX_IMPL_VIA_D3D11, adapterNum, storageID);
+        adapterNum++;
+    } while (sts == MFX_ERR_NONE && !libIterator.isIntelAdapter());
     if (sts)
         return MFX_ERR_UNSUPPORTED;
 

libvpl/src/windows/mfx_library_iterator.h

@@ -99,6 +99,9 @@ class MFXLibraryIterator {
                                        mfxU32 deviceID,
                                        int storageID);
     static mfxStatus GetRegkeyDir(std::wstring &regDir, size_t length, int storageID);
+    bool isIntelAdapter() const {
+        return m_vendorID == INTEL_VENDOR_ID;
+    }
 
 protected:
     // Release the iterator