d3d: simplify DLL loading

For some reason, the d3d9/dxva2/d3d11 DLLs are still optional. But we
don't need to try so hard to keep exact references. In fact, there's no
reason to unload them at all.

So load them once in a central place. For simplicity, the d3d9/d3d11
backends both load all DLLs. (They will error out only if the required
DLLs could not be loaded.)

In theory, we could just call LoadLibrary multiple times (without
calling FreeLibrary), but I'm slightly worried that this could be
detected as a "bug", or that the reference count could even have a low
static limit that could be hit soon.

1 files changed, 6 insertions, 0 deletions

diff --git a/video/decode/d3d.h b/video/decode/d3d.h
index 3f5b8aebe7..15c423ab8c 100644
--- a/video/decode/d3d.h
+++ b/video/decode/d3d.h
@@ -36,6 +36,12 @@ struct d3d_decoder_fmt {
     const struct d3d_decoded_format *format;
 };
 
+// Must call d3d_load_dlls() before accessing. Once this is done, the DLLs
+// remain loaded forever.
+extern HMODULE d3d11_dll, d3d9_dll, dxva2_dll;
+
+void d3d_load_dlls(void);
+
 int d3d_probe_codec(const char *codec);
 
 struct d3d_decoder_fmt d3d_select_decoder_mode(