d3d11va: Link directly to dxgi.dll and d3d11.dll functions if LoadLibrary is unavailable

When targeting the UWP API subset, the LoadLibrary function is not
available (and the fallback, LoadPackagedLibrary, can't be used to
load system DLLs). In these cases, link directly to the functions
in the DLLs instead of trying to load them dynamically at runtime.

Merges Libav commit fd1ffa1f10e940165035ccb79d4a6523da196062.

Signed-off-by: Martin Storsjö <martin@martin.st>

diff --git a/configure b/configure
index aebd5d5da55cadece42a87ee9cb80be0b3a671d3..bf48472219b46935984439d4acb273eaeea72335 100755 (executable)
--- a/configure
+++ b/configure
@@ -6120,6 +6120,10 @@ fi
 
 check_func_headers "windows.h" CreateDIBSection "$gdigrab_indev_extralibs"
 
+# d3d11va requires linking directly to dxgi and d3d11 if not building for
+# the desktop api partition
+enabled LoadLibrary || d3d11va_extralibs="-ldxgi -ld3d11"
+
 enabled vaapi &&
     check_lib vaapi va/va.h vaInitialize -lva
 

diff --git a/libavutil/hwcontext_d3d11va.c b/libavutil/hwcontext_d3d11va.c
index 3940502868c65008d2f61c7377b3c46042d2cd58..5432dd8b51b87b7ff608c370895c71fb10e62a3f 100644 (file)
--- a/libavutil/hwcontext_d3d11va.c
+++ b/libavutil/hwcontext_d3d11va.c
@@ -18,6 +18,10 @@
 
 #include <windows.h>
 
+// Include thread.h before redefining _WIN32_WINNT, to get
+// the right implementation for AVOnce
+#include "thread.h"
+
 #if !defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0600
 #undef _WIN32_WINNT
 #define _WIN32_WINNT 0x0600
@@ -39,6 +43,34 @@
 
 typedef HRESULT(WINAPI *PFN_CREATE_DXGI_FACTORY)(REFIID riid, void **ppFactory);
 
+static AVOnce functions_loaded = AV_ONCE_INIT;
+
+static PFN_CREATE_DXGI_FACTORY mCreateDXGIFactory;
+static PFN_D3D11_CREATE_DEVICE mD3D11CreateDevice;
+
+static av_cold void load_functions(void)
+{
+#if HAVE_LOADLIBRARY
+    // We let these "leak" - this is fine, as unloading has no great benefit, and
+    // Windows will mark a DLL as loaded forever if its internal refcount overflows
+    // from too many LoadLibrary calls.
+    HANDLE d3dlib, dxgilib;
+
+    d3dlib  = LoadLibrary("d3d11.dll");
+    dxgilib = LoadLibrary("dxgi.dll");
+    if (!d3dlib || !dxgilib)
+        return;
+
+    mD3D11CreateDevice = (PFN_D3D11_CREATE_DEVICE) GetProcAddress(d3dlib, "D3D11CreateDevice");
+    mCreateDXGIFactory = (PFN_CREATE_DXGI_FACTORY) GetProcAddress(dxgilib, "CreateDXGIFactory");
+#else
+    // In UWP (which lacks LoadLibrary), CreateDXGIFactory isn't available,
+    // only CreateDXGIFactory1
+    mD3D11CreateDevice = (PFN_D3D11_CREATE_DEVICE) D3D11CreateDevice;
+    mCreateDXGIFactory = (PFN_CREATE_DXGI_FACTORY) CreateDXGIFactory1;
+#endif
+}
+
 typedef struct D3D11VAFramesContext {
     int nb_surfaces_used;
 
@@ -407,50 +439,32 @@ static int d3d11va_device_create(AVHWDeviceContext *ctx, const char *device,
                                  AVDictionary *opts, int flags)
 {
     AVD3D11VADeviceContext *device_hwctx = ctx->hwctx;
-    HANDLE d3dlib;
 
     HRESULT hr;
-    PFN_D3D11_CREATE_DEVICE createD3D;
     IDXGIAdapter           *pAdapter = NULL;
     ID3D10Multithread      *pMultithread;
     UINT creationFlags = D3D11_CREATE_DEVICE_VIDEO_SUPPORT;
+    int ret;
 
-    if (device) {
-        PFN_CREATE_DXGI_FACTORY mCreateDXGIFactory;
-        HMODULE dxgilib = LoadLibrary("dxgi.dll");
-        if (!dxgilib)
-            return AVERROR_UNKNOWN;
-
-        mCreateDXGIFactory = (PFN_CREATE_DXGI_FACTORY) GetProcAddress(dxgilib, "CreateDXGIFactory");
-        if (mCreateDXGIFactory) {
-            IDXGIFactory2 *pDXGIFactory;
-            hr = mCreateDXGIFactory(&IID_IDXGIFactory2, (void **)&pDXGIFactory);
-            if (SUCCEEDED(hr)) {
-                int adapter = atoi(device);
-                if (FAILED(IDXGIFactory2_EnumAdapters(pDXGIFactory, adapter, &pAdapter)))
-                    pAdapter = NULL;
-                IDXGIFactory2_Release(pDXGIFactory);
-            }
-        }
-        FreeLibrary(dxgilib);
-    }
-
-    // We let this "leak" - this is fine, as unloading has no great benefit, and
-    // Windows will mark a DLL as loaded forever if its internal refcount overflows
-    // from too many LoadLibrary calls.
-    d3dlib = LoadLibrary("d3d11.dll");
-    if (!d3dlib) {
-        av_log(ctx, AV_LOG_ERROR, "Failed to load D3D11 library\n");
+    if ((ret = ff_thread_once(&functions_loaded, load_functions)) != 0)
+        return AVERROR_UNKNOWN;
+    if (!mD3D11CreateDevice || !mCreateDXGIFactory) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to load D3D11 library or its functions\n");
         return AVERROR_UNKNOWN;
     }
 
-    createD3D = (PFN_D3D11_CREATE_DEVICE) GetProcAddress(d3dlib, "D3D11CreateDevice");
-    if (!createD3D) {
-        av_log(ctx, AV_LOG_ERROR, "Failed to locate D3D11CreateDevice\n");
-        return AVERROR_UNKNOWN;
+    if (device) {
+        IDXGIFactory2 *pDXGIFactory;
+        hr = mCreateDXGIFactory(&IID_IDXGIFactory2, (void **)&pDXGIFactory);
+        if (SUCCEEDED(hr)) {
+            int adapter = atoi(device);
+            if (FAILED(IDXGIFactory2_EnumAdapters(pDXGIFactory, adapter, &pAdapter)))
+                pAdapter = NULL;
+            IDXGIFactory2_Release(pDXGIFactory);
+        }
     }
 
-    hr = createD3D(pAdapter, pAdapter ? D3D_DRIVER_TYPE_UNKNOWN : D3D_DRIVER_TYPE_HARDWARE, NULL, creationFlags, NULL, 0,
+    hr = mD3D11CreateDevice(pAdapter, pAdapter ? D3D_DRIVER_TYPE_UNKNOWN : D3D_DRIVER_TYPE_HARDWARE, NULL, creationFlags, NULL, 0,
                    D3D11_SDK_VERSION, &device_hwctx->device, NULL, NULL);
     if (pAdapter)
         IDXGIAdapter_Release(pAdapter);