decklink: Add Windows DeckLink project

The code specific to Windows: helps convert `BSTR` instances to
`std::string`s; provides a Windows COM-specific implementation of
`CreateDeckLinkDiscoveryInstance`; aliases CFUUIDGetUUIDBytes,
CFUUIDBytes, and IUnknownUUID (the Linux SDK does this, but for some
reason the Windows SDK does not).

plugins/CMakeLists.txt

@@ -3,6 +3,7 @@ if(WIN32)
 	add_subdirectory(win-wasapi)
 	add_subdirectory(win-dshow)
 	add_subdirectory(win-capture)
+	add_subdirectory(decklink/win)
 elseif(APPLE)
 	add_subdirectory(mac-avcapture)
 	add_subdirectory(mac-capture)

plugins/decklink/platform.hpp

@@ -1,7 +1,12 @@
 #pragma once
 
 #if defined(_WIN32)
-// TODO: Windows support
+#include <DeckLinkAPI.h>
+typedef BSTR decklink_string_t;
+IDeckLinkDiscovery *CreateDeckLinkDiscoveryInstance(void);
+#define IUnknownUUID IID_IUnknown
+typedef REFIID CFUUIDBytes;
+#define CFUUIDGetUUIDBytes(x) x
 #elif defined(__APPLE__)
 #include "mac/decklink-sdk/DeckLinkAPI.h"
 #include <CoreFoundation/CoreFoundation.h>

plugins/decklink/win/CMakeLists.txt

@@ -0,0 +1,46 @@
+project(win-decklink)
+
+include(IDLFileHelper)
+
+set(win-decklink-sdk_IDLS
+	decklink-sdk/DeckLinkAPI.idl
+	)
+
+set(win-decklink-sdk_HEADERS
+	decklink-sdk/DeckLinkAPIVersion.h
+	)
+
+set(win-decklink_HEADERS
+	../platform.hpp
+	../decklink.hpp
+	../decklink-device-instance.hpp
+	../decklink-device-discovery.hpp
+	../decklink-device.hpp
+	../decklink-device-mode.hpp
+	)
+
+set(win-decklink_SOURCES
+	../plugin-main.cpp
+	../decklink.cpp
+	../decklink-device-instance.cpp
+	../decklink-device-discovery.cpp
+	../decklink-device.cpp
+	../decklink-device-mode.cpp
+	platform.cpp)
+
+add_idl_files(win-decklink-sdk_GENERATED_FILES
+	${win-decklink-sdk_IDLS})
+
+include_directories(
+	${CMAKE_CURRENT_BINARY_DIR})
+
+add_library(win-decklink MODULE
+	${win-decklink_SOURCES}
+	${win-decklink_HEADERS}
+	${win-decklink-sdk_HEADERS}
+	${win-decklink-sdk_GENERATED_FILES})
+
+target_link_libraries(win-decklink
+	libobs)
+
+install_obs_plugin_with_data(win-decklink ../data)

plugins/decklink/win/platform.cpp

@@ -0,0 +1,26 @@
+#include "../platform.hpp"
+
+#include <util/platform.h>
+
+IDeckLinkDiscovery *CreateDeckLinkDiscoveryInstance(void)
+{
+	IDeckLinkDiscovery *instance;
+	const HRESULT result = CoCreateInstance(CLSID_CDeckLinkDiscovery,
+			nullptr, CLSCTX_ALL, IID_IDeckLinkDiscovery,
+			(void **)&instance);
+	return result == S_OK ? instance : nullptr;
+}
+
+bool DeckLinkStringToStdString(decklink_string_t input, std::string& output)
+{
+	if (input == nullptr)
+		return false;
+
+	size_t len = wcslen(input);
+	size_t utf8_len = os_wcs_to_utf8(input, len, nullptr, 0);
+
+	output.resize(utf8_len);
+	os_wcs_to_utf8(input, len, &output[0], utf8_len);
+
+	return true;
+}