audio: Port WASAPI to WinRT, remove XAudio2 backend.

XAudio2 doesn't have capture support, so WASAPI was to replace it; the holdout was WinRT, which still needed it as its primary audio target until the WASAPI code code be made to work. The support matrix now looks like: WinXP: directsound by default, winmm as a fallback for buggy drivers. Vista+: WASAPI (directsound and winmm as fallbacks for debugging). WinRT: WASAPI
2017-12-06 12:24:32 -05:00 · 2017-12-06 12:24:32 -05:00 · 351d6d4784
parent 083fe066d5
commit 351d6d4784
30 changed files with 958 additions and 1518 deletions
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -1180,11 +1180,10 @@ elseif(WINDOWS)
    check_include_file(ddraw.h HAVE_DDRAW_H)
    check_include_file(dsound.h HAVE_DSOUND_H)
    check_include_file(dinput.h HAVE_DINPUT_H)
    check_include_file(xaudio2.h HAVE_XAUDIO2_H)
    check_include_file(mmdeviceapi.h HAVE_MMDEVICEAPI_H)
    check_include_file(audioclient.h HAVE_AUDIOCLIENT_H)
    check_include_file(dxgi.h HAVE_DXGI_H)
-    if(HAVE_D3D_H OR HAVE_D3D11_H OR HAVE_DDRAW_H OR HAVE_DSOUND_H OR HAVE_DINPUT_H OR HAVE_XAUDIO2_H)
+    if(HAVE_D3D_H OR HAVE_D3D11_H OR HAVE_DDRAW_H OR HAVE_DSOUND_H OR HAVE_DINPUT_H)
      set(HAVE_DIRECTX TRUE)
      if(NOT CMAKE_COMPILER_IS_MINGW AND NOT USE_WINSDK_DIRECTX)
      # TODO: change $ENV{DXSDL_DIR} to get the path from the include checks
@ -1207,12 +1206,6 @@ elseif(WINDOWS)
      set(SOURCE_FILES ${SOURCE_FILES} ${DSOUND_AUDIO_SOURCES})
    endif()
    if(HAVE_XAUDIO2_H)
      set(SDL_AUDIO_DRIVER_XAUDIO2 1)
      file(GLOB XAUDIO2_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/xaudio2/*.c)
      set(SOURCE_FILES ${SOURCE_FILES} ${XAUDIO2_AUDIO_SOURCES})
    endif()
    if(HAVE_AUDIOCLIENT_H AND HAVE_MMDEVICEAPI_H)
      set(SDL_AUDIO_DRIVER_WASAPI 1)
      file(GLOB WASAPI_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/wasapi/*.c)
--- a/VisualC-WinRT/UWP_VS2015/SDL-UWP.vcxproj
+++ b/VisualC-WinRT/UWP_VS2015/SDL-UWP.vcxproj
@ -84,8 +84,7 @@
    <ClInclude Include="..\..\src\audio\SDL_audio_c.h" />
    <ClInclude Include="..\..\src\audio\SDL_sysaudio.h" />
    <ClInclude Include="..\..\src\audio\SDL_wave.h" />
-    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2.h" />
+    <ClInclude Include="..\..\src\audio\wasapi\SDL_wasapi.h" />
    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.h" />
    <ClInclude Include="..\..\src\core\windows\SDL_directx.h" />
    <ClInclude Include="..\..\src\core\windows\SDL_windows.h" />
    <ClInclude Include="..\..\src\core\windows\SDL_xinput.h" />
@ -175,8 +174,8 @@
    <ClCompile Include="..\..\src\audio\SDL_audiotypecvt.c" />
    <ClCompile Include="..\..\src\audio\SDL_mixer.c" />
    <ClCompile Include="..\..\src\audio\SDL_wave.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c" />
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.cpp">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi_winrt.cpp">
      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</CompileAsWinRT>
      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|ARM'">true</CompileAsWinRT>
      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</CompileAsWinRT>
--- a/VisualC-WinRT/UWP_VS2015/SDL-UWP.vcxproj.filters
+++ b/VisualC-WinRT/UWP_VS2015/SDL-UWP.vcxproj.filters
@ -183,9 +183,6 @@
    <ClInclude Include="..\..\src\audio\SDL_wave.h">
      <Filter>Source Files</Filter>
    </ClInclude>
    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.h">
      <Filter>Source Files</Filter>
    </ClInclude>
    <ClInclude Include="..\..\src\core\windows\SDL_directx.h">
      <Filter>Source Files</Filter>
    </ClInclude>
@ -390,7 +387,7 @@
    <ClInclude Include="..\..\src\video\winrt\SDL_winrtvideo_cpp.h">
      <Filter>Source Files</Filter>
    </ClInclude>
-    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2.h">
+    <ClInclude Include="..\..\src\audio\wasapi\SDL_wasapi.h">
      <Filter>Source Files</Filter>
    </ClInclude>
    <ClInclude Include="..\..\src\video\winrt\SDL_winrtgamebar_cpp.h">
@ -449,7 +446,7 @@
    <ClCompile Include="..\..\src\audio\SDL_wave.c">
      <Filter>Source Files</Filter>
    </ClCompile>
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.cpp">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi_winrt.cpp">
      <Filter>Source Files</Filter>
    </ClCompile>
    <ClCompile Include="..\..\src\core\windows\SDL_windows.c">
@ -722,7 +719,7 @@
    <ClCompile Include="..\..\src\video\winrt\SDL_winrtvideo.cpp">
      <Filter>Source Files</Filter>
    </ClCompile>
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c">
      <Filter>Source Files</Filter>
    </ClCompile>
    <ClCompile Include="..\..\src\video\winrt\SDL_winrtgamebar.cpp">
--- a/VisualC-WinRT/WinPhone80_VS2012/SDL-WinPhone80.vcxproj
+++ b/VisualC-WinRT/WinPhone80_VS2012/SDL-WinPhone80.vcxproj
@ -91,7 +91,7 @@
      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
      <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalDependencies>DXGI.lib;d3d11.lib;xaudio2.lib;WindowsPhoneCore.lib;RuntimeObject.lib;PhoneAppModelHost.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>DXGI.lib;d3d11.lib;WindowsPhoneCore.lib;RuntimeObject.lib;PhoneAppModelHost.lib;%(AdditionalDependencies)</AdditionalDependencies>
    </Link>
  </ItemDefinitionGroup>
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@ -108,7 +108,7 @@
      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
      <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalDependencies>DXGI.lib;d3d11.lib;xaudio2.lib;WindowsPhoneCore.lib;RuntimeObject.lib;PhoneAppModelHost.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>DXGI.lib;d3d11.lib;WindowsPhoneCore.lib;RuntimeObject.lib;PhoneAppModelHost.lib;%(AdditionalDependencies)</AdditionalDependencies>
    </Link>
  </ItemDefinitionGroup>
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@ -126,7 +126,7 @@
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      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
      <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalDependencies>DXGI.lib;d3d11.lib;xaudio2.lib;WindowsPhoneCore.lib;RuntimeObject.lib;PhoneAppModelHost.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>DXGI.lib;d3d11.lib;WindowsPhoneCore.lib;RuntimeObject.lib;PhoneAppModelHost.lib;%(AdditionalDependencies)</AdditionalDependencies>
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@ -143,7 +143,7 @@
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      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
      <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalDependencies>DXGI.lib;d3d11.lib;xaudio2.lib;WindowsPhoneCore.lib;RuntimeObject.lib;PhoneAppModelHost.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>DXGI.lib;d3d11.lib;WindowsPhoneCore.lib;RuntimeObject.lib;PhoneAppModelHost.lib;%(AdditionalDependencies)</AdditionalDependencies>
    </Link>
  </ItemDefinitionGroup>
  <ItemGroup>
@ -211,7 +211,7 @@
    <ClInclude Include="..\..\src\audio\SDL_audio_c.h" />
    <ClInclude Include="..\..\src\audio\SDL_sysaudio.h" />
    <ClInclude Include="..\..\src\audio\SDL_wave.h" />
-    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.h" />
+    <ClInclude Include="..\..\src\audio\wasapi\SDL_wasapi.h" />
    <ClInclude Include="..\..\src\core\windows\SDL_windows.h" />
    <ClInclude Include="..\..\src\core\winrt\SDL_winrtapp_common.h" />
    <ClInclude Include="..\..\src\core\winrt\SDL_winrtapp_direct3d.h" />
@ -292,8 +292,8 @@
    <ClCompile Include="..\..\src\audio\SDL_audiotypecvt.c" />
    <ClCompile Include="..\..\src\audio\SDL_mixer.c" />
    <ClCompile Include="..\..\src\audio\SDL_wave.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c" />
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.cpp">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi_winrt.cpp">
      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|ARM'">true</CompileAsWinRT>
      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Release|ARM'">true</CompileAsWinRT>
      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</CompileAsWinRT>
--- a/VisualC-WinRT/WinPhone80_VS2012/SDL-WinPhone80.vcxproj.filters
+++ b/VisualC-WinRT/WinPhone80_VS2012/SDL-WinPhone80.vcxproj.filters
@ -168,7 +168,7 @@
    <ClInclude Include="..\..\src\audio\SDL_wave.h">
      <Filter>Source Files</Filter>
    </ClInclude>
-    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.h">
+    <ClInclude Include="..\..\src\audio\wasapi\SDL_wasapi.h">
      <Filter>Source Files</Filter>
    </ClInclude>
    <ClInclude Include="..\..\src\core\windows\SDL_windows.h">
@ -413,10 +413,10 @@
    <ClCompile Include="..\..\src\audio\SDL_wave.c">
      <Filter>Source Files</Filter>
    </ClCompile>
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c">
      <Filter>Source Files</Filter>
    </ClCompile>
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.cpp">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi_winrt.cpp">
      <Filter>Source Files</Filter>
    </ClCompile>
    <ClCompile Include="..\..\src\core\windows\SDL_windows.c">
--- a/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj
+++ b/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj
@ -76,7 +76,7 @@
    <ClInclude Include="..\..\src\audio\SDL_audio_c.h" />
    <ClInclude Include="..\..\src\audio\SDL_sysaudio.h" />
    <ClInclude Include="..\..\src\audio\SDL_wave.h" />
-    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.h" />
+    <ClInclude Include="..\..\src\audio\wasapi\SDL_wasapi.h" />
    <ClInclude Include="..\..\src\core\windows\SDL_windows.h" />
    <ClInclude Include="..\..\src\core\winrt\SDL_winrtapp_common.h" />
    <ClInclude Include="..\..\src\core\winrt\SDL_winrtapp_direct3d.h" />
@ -158,8 +158,8 @@
    <ClCompile Include="..\..\src\audio\SDL_audiotypecvt.c" />
    <ClCompile Include="..\..\src\audio\SDL_mixer.c" />
    <ClCompile Include="..\..\src\audio\SDL_wave.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c" />
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.cpp">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi_winrt.cpp">
      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</CompileAsWinRT>
      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|ARM'">true</CompileAsWinRT>
      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</CompileAsWinRT>
@ -407,7 +407,7 @@
      <SubSystem>Console</SubSystem>
      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>DXGI.lib;d3d11.lib;xaudio2.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>DXGI.lib;d3d11.lib;%(AdditionalDependencies)</AdditionalDependencies>
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  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
@ -421,7 +421,7 @@
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      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>DXGI.lib;d3d11.lib;xaudio2.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>DXGI.lib;d3d11.lib;%(AdditionalDependencies)</AdditionalDependencies>
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@ -435,7 +435,7 @@
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      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>DXGI.lib;d3d11.lib;xaudio2.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>DXGI.lib;d3d11.lib;%(AdditionalDependencies)</AdditionalDependencies>
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@ -449,7 +449,7 @@
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      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>DXGI.lib;d3d11.lib;xaudio2.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>DXGI.lib;d3d11.lib;%(AdditionalDependencies)</AdditionalDependencies>
    </Link>
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  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
--- a/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj.filters
+++ b/VisualC-WinRT/WinPhone81_VS2013/SDL-WinPhone81.vcxproj.filters
@ -183,7 +183,7 @@
    <ClInclude Include="..\..\src\audio\SDL_wave.h">
      <Filter>Source Files</Filter>
    </ClInclude>
-    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.h">
+    <ClInclude Include="..\..\src\audio\wasapi\SDL_wasapi.h">
      <Filter>Source Files</Filter>
    </ClInclude>
    <ClInclude Include="..\..\src\core\windows\SDL_windows.h">
@ -420,10 +420,10 @@
    <ClCompile Include="..\..\src\audio\SDL_wave.c">
      <Filter>Source Files</Filter>
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-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c">
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-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.cpp">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi_winrt.cpp">
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--- a/VisualC-WinRT/WinRT80_VS2012/SDL-WinRT80.vcxproj
+++ b/VisualC-WinRT/WinRT80_VS2012/SDL-WinRT80.vcxproj
@ -37,8 +37,8 @@
    <ClCompile Include="..\..\src\audio\SDL_audiotypecvt.c" />
    <ClCompile Include="..\..\src\audio\SDL_mixer.c" />
    <ClCompile Include="..\..\src\audio\SDL_wave.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c" />
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.cpp">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi_winrt.cpp">
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@ -293,7 +293,7 @@
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    <ClInclude Include="..\..\src\audio\SDL_sysaudio.h" />
    <ClInclude Include="..\..\src\audio\SDL_wave.h" />
-    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.h" />
+    <ClInclude Include="..\..\src\audio\wasapi\SDL_wasapi.h" />
    <ClInclude Include="..\..\src\core\windows\SDL_directx.h" />
    <ClInclude Include="..\..\src\core\windows\SDL_windows.h" />
    <ClInclude Include="..\..\src\core\windows\SDL_xinput.h" />
@ -483,7 +483,7 @@
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      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
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+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
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@ -497,7 +497,7 @@
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+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
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@ -511,7 +511,7 @@
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+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
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@ -525,7 +525,7 @@
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+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
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@ -539,7 +539,7 @@
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+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
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@ -553,7 +553,7 @@
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+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
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--- a/VisualC-WinRT/WinRT80_VS2012/SDL-WinRT80.vcxproj.filters
+++ b/VisualC-WinRT/WinRT80_VS2012/SDL-WinRT80.vcxproj.filters
@ -214,10 +214,10 @@
    <ClCompile Include="..\..\src\core\windows\SDL_windows.c">
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-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c">
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-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.cpp">
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@ -618,7 +618,7 @@
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-    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.h">
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--- a/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj
+++ b/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj
@ -84,7 +84,7 @@
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    <ClInclude Include="..\..\src\audio\SDL_wave.h" />
-    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.h" />
+    <ClInclude Include="..\..\src\audio\wasapi\SDL_wasapi.h" />
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@ -172,8 +172,8 @@
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    <ClCompile Include="..\..\src\audio\SDL_wave.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c" />
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.cpp">
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      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>xinput.lib;xaudio2.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
    </Link>
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|arm'">
@ -512,7 +512,7 @@
      <SubSystem>Console</SubSystem>
      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>xinput.lib;xaudio2.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
    </Link>
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|arm'">
@ -526,7 +526,7 @@
      <SubSystem>Console</SubSystem>
      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>xinput.lib;xaudio2.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
    </Link>
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
@ -540,7 +540,7 @@
      <SubSystem>Console</SubSystem>
      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>xinput.lib;xaudio2.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
    </Link>
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
@ -554,7 +554,7 @@
      <SubSystem>Console</SubSystem>
      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
      <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>xinput.lib;xaudio2.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>xinput.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
    </Link>
  </ItemDefinitionGroup>
  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
--- a/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj.filters
+++ b/VisualC-WinRT/WinRT81_VS2013/SDL-WinRT81.vcxproj.filters
@ -183,7 +183,7 @@
    <ClInclude Include="..\..\src\audio\SDL_wave.h">
      <Filter>Source Files</Filter>
    </ClInclude>
-    <ClInclude Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.h">
+    <ClInclude Include="..\..\src\audio\wasapi\SDL_wasapi.h">
      <Filter>Source Files</Filter>
    </ClInclude>
    <ClInclude Include="..\..\src\core\windows\SDL_windows.h">
@ -440,10 +440,10 @@
    <ClCompile Include="..\..\src\audio\SDL_wave.c">
      <Filter>Source Files</Filter>
    </ClCompile>
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c">
      <Filter>Source Files</Filter>
    </ClCompile>
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2_winrthelpers.cpp">
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi_winrt.cpp">
      <Filter>Source Files</Filter>
    </ClCompile>
    <ClCompile Include="..\..\src\core\windows\SDL_windows.c">
--- a/VisualC/SDL/SDL.vcxproj
+++ b/VisualC/SDL/SDL.vcxproj
@ -291,6 +291,7 @@
    <ClInclude Include="..\..\src\audio\directsound\SDL_directsound.h" />
    <ClInclude Include="..\..\src\audio\disk\SDL_diskaudio.h" />
    <ClInclude Include="..\..\src\audio\dummy\SDL_dummyaudio.h" />
    <ClInclude Include="..\..\src\audio\wasapi\SDL_wasapi.h" />
    <ClInclude Include="..\..\src\audio\SDL_audio_c.h" />
    <ClInclude Include="..\..\src\audio\SDL_audiodev_c.h" />
    <ClInclude Include="..\..\src\audio\SDL_sysaudio.h" />
@ -389,9 +390,9 @@
    <ClCompile Include="..\..\src\audio\SDL_audiotypecvt.c" />
    <ClCompile Include="..\..\src\audio\SDL_mixer.c" />
    <ClCompile Include="..\..\src\audio\SDL_wave.c" />
    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c" />
    <ClCompile Include="..\..\src\audio\winmm\SDL_winmm.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c" />
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c" />
    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi_win32.c" />
    <ClCompile Include="..\..\src\core\windows\SDL_windows.c" />
    <ClCompile Include="..\..\src\core\windows\SDL_xinput.c" />
    <ClCompile Include="..\..\src\cpuinfo\SDL_cpuinfo.c" />
--- a/VisualC/SDL/SDL.vcxproj.filters
+++ b/VisualC/SDL/SDL.vcxproj.filters
@ -438,7 +438,8 @@
    <ClCompile Include="..\..\src\video\windows\SDL_windowsvideo.c" />
    <ClCompile Include="..\..\src\video\windows\SDL_windowswindow.c" />
    <ClCompile Include="..\..\src\audio\winmm\SDL_winmm.c" />
-    <ClCompile Include="..\..\src\audio\xaudio2\SDL_xaudio2.c" />
+    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi.c" />
    <ClCompile Include="..\..\src\audio\wasapi\SDL_wasapi_win32.c" />
    <ClCompile Include="..\..\src\core\windows\SDL_xinput.c" />
    <ClCompile Include="..\..\src\haptic\windows\SDL_xinputhaptic.c" />
    <ClCompile Include="..\..\src\joystick\windows\SDL_xinputjoystick.c" />
--- a/configure.in
+++ b/configure.in
@ -2978,7 +2978,6 @@ AC_HELP_STRING([--enable-directx], [use DirectX for Windows audio/video [[defaul
        AC_CHECK_HEADER(dsound.h, have_dsound=yes)
        AC_CHECK_HEADER(dinput.h, have_dinput=yes)
        AC_CHECK_HEADER(dxgi.h, have_dxgi=yes)
        AC_CHECK_HEADER(xaudio2.h, have_xaudio2=yes)
        AC_CHECK_HEADER(xinput.h, have_xinput=yes)
        AC_CHECK_HEADER(mmdeviceapi.h, have_wasapi=yes)
        AC_CHECK_HEADER(audioclient.h,,have_wasapi=no)
@ -3486,10 +3485,6 @@ AC_HELP_STRING([--enable-render-d3d], [enable the Direct3D render driver [[defau
                AC_DEFINE(SDL_AUDIO_DRIVER_DSOUND, 1, [ ])
                SOURCES="$SOURCES $srcdir/src/audio/directsound/*.c"
            fi
            if test x$have_xaudio2 = xyes; then
                AC_DEFINE(SDL_AUDIO_DRIVER_XAUDIO2, 1, [ ])
                SOURCES="$SOURCES $srcdir/src/audio/xaudio2/*.c"
            fi
            if test x$have_wasapi = xyes; then
                AC_DEFINE(SDL_AUDIO_DRIVER_WASAPI, 1, [ ])
                SOURCES="$SOURCES $srcdir/src/audio/wasapi/*.c"
--- a/docs/README-winrt.md
+++ b/docs/README-winrt.md
@ -70,7 +70,10 @@ Here is a rough list of what works, and what doesn't:
    SDL_GetPerformanceFrequency(), etc.)
  * file I/O via SDL_RWops
  * mouse input  (unsupported on Windows Phone)
-  * audio, via a modified version of SDL's XAudio2 backend
+  * audio, via SDL's WASAPI backend (if you want to record, your app must 
    have "Microphone" capabilities enabled in its manifest, and the user must 
    not have blocked access. Otherwise, capture devices will fail to work,
    presenting as a device disconnect shortly after opening it.)
  * .DLL file loading.  Libraries *MUST* be packaged inside applications.  Loading
    anything outside of the app is not supported.
  * system path retrieval via SDL's filesystem APIs
--- a/include/SDL_config.h.cmake
+++ b/include/SDL_config.h.cmake
@ -202,7 +202,6 @@
 #cmakedefine HAVE_DDRAW_H @HAVE_DDRAW_H@
 #cmakedefine HAVE_DSOUND_H @HAVE_DSOUND_H@
 #cmakedefine HAVE_DINPUT_H @HAVE_DINPUT_H@
 #cmakedefine HAVE_XAUDIO2_H @HAVE_XAUDIO2_H@
 #cmakedefine HAVE_XINPUT_H @HAVE_XINPUT_H@
 #cmakedefine HAVE_DXGI_H @HAVE_DXGI_H@
 #cmakedefine HAVE_XINPUT_GAMEPAD_EX @HAVE_XINPUT_GAMEPAD_EX@
@ -259,7 +258,6 @@
 #cmakedefine SDL_AUDIO_DRIVER_SUNAUDIO @SDL_AUDIO_DRIVER_SUNAUDIO@
 #cmakedefine SDL_AUDIO_DRIVER_WASAPI @SDL_AUDIO_DRIVER_WASAPI@
 #cmakedefine SDL_AUDIO_DRIVER_WINMM @SDL_AUDIO_DRIVER_WINMM@
 #cmakedefine SDL_AUDIO_DRIVER_XAUDIO2 @SDL_AUDIO_DRIVER_XAUDIO2@
 /* Enable various input drivers */
 #cmakedefine SDL_INPUT_LINUXEV @SDL_INPUT_LINUXEV@
--- a/include/SDL_config.h.in
+++ b/include/SDL_config.h.in
@ -259,7 +259,6 @@
 #undef SDL_AUDIO_DRIVER_SUNAUDIO
 #undef SDL_AUDIO_DRIVER_WASAPI
 #undef SDL_AUDIO_DRIVER_WINMM
 #undef SDL_AUDIO_DRIVER_XAUDIO2
 /* Enable various input drivers */
 #undef SDL_INPUT_LINUXEV
--- a/include/SDL_config_windows.h
+++ b/include/SDL_config_windows.h
@ -179,7 +179,6 @@ typedef unsigned int uintptr_t;
 /* Enable various audio drivers */
 #define SDL_AUDIO_DRIVER_WASAPI 1
 #define SDL_AUDIO_DRIVER_DSOUND 1
 #define SDL_AUDIO_DRIVER_XAUDIO2    0
 #define SDL_AUDIO_DRIVER_WINMM  1
 #define SDL_AUDIO_DRIVER_DISK   1
 #define SDL_AUDIO_DRIVER_DUMMY  1
--- a/include/SDL_config_winrt.h
+++ b/include/SDL_config_winrt.h
@ -175,7 +175,7 @@ typedef unsigned int uintptr_t;
 #define HAVE__FSEEKI64 1
 /* Enable various audio drivers */
-#define SDL_AUDIO_DRIVER_XAUDIO2    1
+#define SDL_AUDIO_DRIVER_WASAPI 1
 #define SDL_AUDIO_DRIVER_DISK   1
 #define SDL_AUDIO_DRIVER_DUMMY  1
--- a/src/SDL_internal.h
+++ b/src/SDL_internal.h
@ -29,7 +29,7 @@
 /* This is for a variable-length array at the end of a struct:
    struct x { int y; char z[SDL_VARIABLE_LENGTH_ARRAY]; };
   Use this because GCC 2 needs different magic than other compilers. */
-#if (defined(__GNUC__) && (__GNUC__ <= 2)) || defined(__CC_ARM)
+#if (defined(__GNUC__) && (__GNUC__ <= 2)) || defined(__CC_ARM) || defined(__cplusplus)
 #define SDL_VARIABLE_LENGTH_ARRAY 1
 #else
 #define SDL_VARIABLE_LENGTH_ARRAY
--- a/src/audio/SDL_audio.c
+++ b/src/audio/SDL_audio.c
@ -71,9 +71,6 @@ static const AudioBootStrap *const bootstrap[] = {
 #if SDL_AUDIO_DRIVER_WASAPI
    &WASAPI_bootstrap,
 #endif
 #if SDL_AUDIO_DRIVER_XAUDIO2
    &XAUDIO2_bootstrap,
 #endif
 #if SDL_AUDIO_DRIVER_DSOUND
    &DSOUND_bootstrap,
 #endif
@ -233,6 +230,11 @@ SDL_AudioThreadDeinit_Default(_THIS)
 {                               /* no-op. */
 }
 static void
 SDL_AudioBeginLoopIteration_Default(_THIS)
 {                               /* no-op. */
 }
 static void
 SDL_AudioWaitDevice_Default(_THIS)
 {                               /* no-op. */
@ -353,6 +355,7 @@ finish_audio_entry_points_init(void)
    FILL_STUB(OpenDevice);
    FILL_STUB(ThreadInit);
    FILL_STUB(ThreadDeinit);
    FILL_STUB(BeginLoopIteration);
    FILL_STUB(WaitDevice);
    FILL_STUB(PlayDevice);
    FILL_STUB(GetPendingBytes);
@ -642,6 +645,7 @@ SDL_RunAudio(void *devicep)
    SDL_AudioDevice *device = (SDL_AudioDevice *) devicep;
    void *udata = device->callbackspec.userdata;
    SDL_AudioCallback callback = device->callbackspec.callback;
    int data_len = 0;
    Uint8 *data;
    SDL_assert(!device->iscapture);
@ -655,7 +659,8 @@ SDL_RunAudio(void *devicep)
    /* Loop, filling the audio buffers */
    while (!SDL_AtomicGet(&device->shutdown)) {
-        const int data_len = device->callbackspec.size;
+        current_audio.impl.BeginLoopIteration(device);
        data_len = device->callbackspec.size;
        /* Fill the current buffer with sound */
        if (!device->stream && SDL_AtomicGet(&device->enabled)) {
@ -754,6 +759,8 @@ SDL_CaptureAudio(void *devicep)
        int still_need;
        Uint8 *ptr;
        current_audio.impl.BeginLoopIteration(device);
        if (SDL_AtomicGet(&device->paused)) {
            SDL_Delay(delay);  /* just so we don't cook the CPU. */
            if (device->stream) {
--- a/src/audio/SDL_sysaudio.h
+++ b/src/audio/SDL_sysaudio.h
@ -68,6 +68,7 @@ typedef struct SDL_AudioDriverImpl
    int (*OpenDevice) (_THIS, void *handle, const char *devname, int iscapture);
    void (*ThreadInit) (_THIS); /* Called by audio thread at start */
    void (*ThreadDeinit) (_THIS); /* Called by audio thread at end */
    void (*BeginLoopIteration)(_THIS);  /* Called by audio thread at top of loop */
    void (*WaitDevice) (_THIS);
    void (*PlayDevice) (_THIS);
    int (*GetPendingBytes) (_THIS);
@ -193,7 +194,6 @@ extern AudioBootStrap ESD_bootstrap;
 extern AudioBootStrap NACLAUDIO_bootstrap;
 extern AudioBootStrap NAS_bootstrap;
 extern AudioBootStrap WASAPI_bootstrap;
 extern AudioBootStrap XAUDIO2_bootstrap;
 extern AudioBootStrap DSOUND_bootstrap;
 extern AudioBootStrap WINMM_bootstrap;
 extern AudioBootStrap PAUDIO_bootstrap;
--- a/src/audio/wasapi/SDL_wasapi.c
+++ b/src/audio/wasapi/SDL_wasapi.c
@ -37,14 +37,9 @@
 #include "SDL_wasapi.h"
 static const ERole SDL_WASAPI_role = eConsole;  /* !!! FIXME: should this be eMultimedia? Should be a hint? */
 /* This is global to the WASAPI target, to handle hotplug and default device lookup. */
 static IMMDeviceEnumerator *enumerator = NULL;
 /* these increment as default devices change. Opened default devices pick up changes in their threads. */
-static SDL_atomic_t default_playback_generation;
+SDL_atomic_t WASAPI_DefaultPlaybackGeneration;
-static SDL_atomic_t default_capture_generation;
+SDL_atomic_t WASAPI_DefaultCaptureGeneration;
 /* This is a list of device id strings we have inflight, so we have consistent pointers to the same device. */
 typedef struct DevIdList
@ -55,173 +50,11 @@ typedef struct DevIdList
 static DevIdList *deviceid_list = NULL;
 /* handle to Avrt.dll--Vista and later!--for flagging the callback thread as "Pro Audio" (low latency). */
 #ifndef __WINRT__
 static HMODULE libavrt = NULL;
 #endif
 typedef HANDLE (WINAPI *pfnAvSetMmThreadCharacteristicsW)(LPWSTR,LPDWORD);
 typedef BOOL (WINAPI *pfnAvRevertMmThreadCharacteristics)(HANDLE);
 static pfnAvSetMmThreadCharacteristicsW pAvSetMmThreadCharacteristicsW = NULL;
 static pfnAvRevertMmThreadCharacteristics pAvRevertMmThreadCharacteristics = NULL;
 /* Some GUIDs we need to know without linking to libraries that aren't available before Vista. */
 static const CLSID SDL_CLSID_MMDeviceEnumerator = { 0xbcde0395, 0xe52f, 0x467c, { 0x8e, 0x3d, 0xc4, 0x57, 0x92, 0x91, 0x69, 0x2e } };
 static const IID SDL_IID_IMMDeviceEnumerator = { 0xa95664d2, 0x9614, 0x4f35, { 0xa7, 0x46, 0xde, 0x8d, 0xb6, 0x36, 0x17, 0xe6 } };
 static const IID SDL_IID_IMMNotificationClient = { 0x7991eec9, 0x7e89, 0x4d85, { 0x83, 0x90, 0x6c, 0x70, 0x3c, 0xec, 0x60, 0xc0 } };
 static const IID SDL_IID_IMMEndpoint = { 0x1be09788, 0x6894, 0x4089, { 0x85, 0x86, 0x9a, 0x2a, 0x6c, 0x26, 0x5a, 0xc5 } };
 static const IID SDL_IID_IAudioClient = { 0x1cb9ad4c, 0xdbfa, 0x4c32, { 0xb1, 0x78, 0xc2, 0xf5, 0x68, 0xa7, 0x03, 0xb2 } };
 static const IID SDL_IID_IAudioRenderClient = { 0xf294acfc, 0x3146, 0x4483,{ 0xa7, 0xbf, 0xad, 0xdc, 0xa7, 0xc2, 0x60, 0xe2 } };
 static const IID SDL_IID_IAudioCaptureClient = { 0xc8adbd64, 0xe71e, 0x48a0,{ 0xa4, 0xde, 0x18, 0x5c, 0x39, 0x5c, 0xd3, 0x17 } };
 static const GUID SDL_KSDATAFORMAT_SUBTYPE_PCM = { 0x00000001, 0x0000, 0x0010,{ 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 } };
 static const GUID SDL_KSDATAFORMAT_SUBTYPE_IEEE_FLOAT = { 0x00000003, 0x0000, 0x0010,{ 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 } };
 static const PROPERTYKEY SDL_PKEY_Device_FriendlyName = { { 0xa45c254e, 0xdf1c, 0x4efd, { 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0, } }, 14 };
 /* PropVariantInit() is an inline function/macro in PropIdl.h that calls the C runtime's memset() directly. Use ours instead, to avoid dependency. */ 
 #ifdef PropVariantInit
 #undef PropVariantInit
 #endif
 #define PropVariantInit(p) SDL_zerop(p)
 static void AddWASAPIDevice(const SDL_bool iscapture, IMMDevice *device, LPCWSTR devid);
 static void RemoveWASAPIDevice(const SDL_bool iscapture, LPCWSTR devid);
 /* We need a COM subclass of IMMNotificationClient for hotplug support, which is
   easy in C++, but we have to tapdance more to make work in C.
   Thanks to this page for coaching on how to make this work:
     https://www.codeproject.com/Articles/13601/COM-in-plain-C */
 typedef struct SDLMMNotificationClient
 {
    const IMMNotificationClientVtbl *lpVtbl;
    SDL_atomic_t refcount;
 } SDLMMNotificationClient;
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_QueryInterface(IMMNotificationClient *this, REFIID iid, void **ppv)
 {
    if ((WIN_IsEqualIID(iid, &IID_IUnknown)) || (WIN_IsEqualIID(iid, &SDL_IID_IMMNotificationClient)))
    {
        *ppv = this;
        this->lpVtbl->AddRef(this);
        return S_OK;
    }
    *ppv = NULL;
    return E_NOINTERFACE;
 }
 static ULONG STDMETHODCALLTYPE
 SDLMMNotificationClient_AddRef(IMMNotificationClient *ithis)
 {
    SDLMMNotificationClient *this = (SDLMMNotificationClient *) ithis;
    return (ULONG) (SDL_AtomicIncRef(&this->refcount) + 1);
 }
 static ULONG STDMETHODCALLTYPE
 SDLMMNotificationClient_Release(IMMNotificationClient *ithis)
 {
    /* this is a static object; we don't ever free it. */
    SDLMMNotificationClient *this = (SDLMMNotificationClient *) ithis;
    const ULONG retval = SDL_AtomicDecRef(&this->refcount);
    if (retval == 0) {
        SDL_AtomicSet(&this->refcount, 0);  /* uhh... */
        return 0;
    }
    return retval - 1;
 }
 /* These are the entry points called when WASAPI device endpoints change. */
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_OnDefaultDeviceChanged(IMMNotificationClient *ithis, EDataFlow flow, ERole role, LPCWSTR pwstrDeviceId)
 {
    if (role != SDL_WASAPI_role) {
        return S_OK;  /* ignore it. */
    }
    /* Increment the "generation," so opened devices will pick this up in their threads. */
    switch (flow) {
        case eRender:
            SDL_AtomicAdd(&default_playback_generation, 1);
            break;
        case eCapture:
            SDL_AtomicAdd(&default_capture_generation, 1);
            break;
        case eAll:
            SDL_AtomicAdd(&default_playback_generation, 1);
            SDL_AtomicAdd(&default_capture_generation, 1);
            break;
        default:
            SDL_assert(!"uhoh, unexpected OnDefaultDeviceChange flow!");
            break;
    }
    return S_OK;
 }
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_OnDeviceAdded(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId)
 {
    /* we ignore this; devices added here then progress to ACTIVE, if appropriate, in 
       OnDeviceStateChange, making that a better place to deal with device adds. More 
       importantly: the first time you plug in a USB audio device, this callback will 
       fire, but when you unplug it, it isn't removed (it's state changes to NOTPRESENT).
       Plugging it back in won't fire this callback again. */
    return S_OK;
 }
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_OnDeviceRemoved(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId)
 {
    /* See notes in OnDeviceAdded handler about why we ignore this. */
    return S_OK;
 }
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_OnDeviceStateChanged(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId, DWORD dwNewState)
 {
    IMMDevice *device = NULL;
    if (SUCCEEDED(IMMDeviceEnumerator_GetDevice(enumerator, pwstrDeviceId, &device))) {
        IMMEndpoint *endpoint = NULL;
        if (SUCCEEDED(IMMDevice_QueryInterface(device, &SDL_IID_IMMEndpoint, (void **) &endpoint))) {
            EDataFlow flow;
            if (SUCCEEDED(IMMEndpoint_GetDataFlow(endpoint, &flow))) {
                const SDL_bool iscapture = (flow == eCapture);
                if (dwNewState == DEVICE_STATE_ACTIVE) {
                    AddWASAPIDevice(iscapture, device, pwstrDeviceId);
                } else {
                    RemoveWASAPIDevice(iscapture, pwstrDeviceId);
                }
            }
            IMMEndpoint_Release(endpoint);
        }
        IMMDevice_Release(device);
    }
    return S_OK;
 }
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_OnPropertyValueChanged(IMMNotificationClient *this, LPCWSTR pwstrDeviceId, const PROPERTYKEY key)
 {
    return S_OK;  /* we don't care about these. */
 }
 static const IMMNotificationClientVtbl notification_client_vtbl = {
    SDLMMNotificationClient_QueryInterface,
    SDLMMNotificationClient_AddRef,
    SDLMMNotificationClient_Release,
    SDLMMNotificationClient_OnDeviceStateChanged,
    SDLMMNotificationClient_OnDeviceAdded,
    SDLMMNotificationClient_OnDeviceRemoved,
    SDLMMNotificationClient_OnDefaultDeviceChanged,
    SDLMMNotificationClient_OnPropertyValueChanged
 };
 static SDLMMNotificationClient notification_client = { &notification_client_vtbl, { 1 } };
 static SDL_bool
 WStrEqual(const WCHAR *a, const WCHAR *b)
@ -236,10 +69,22 @@ WStrEqual(const WCHAR *a, const WCHAR *b)
    return *b == 0;
 }
 static size_t
 WStrLen(const WCHAR *wstr)
 {
    size_t retval = 0;
    if (wstr) {
        while (*(wstr++)) {
            retval++;
        }
    }
    return retval;
 }
 static WCHAR *
 WStrDupe(const WCHAR *wstr)
 {
-    const int len = (lstrlenW(wstr) + 1) * sizeof (WCHAR);
+    const int len = (WStrLen(wstr) + 1) * sizeof (WCHAR);
    WCHAR *retval = (WCHAR *) SDL_malloc(len);
    if (retval) {
        SDL_memcpy(retval, wstr, len);
@ -247,8 +92,9 @@ WStrDupe(const WCHAR *wstr)
    return retval;
 }
-static void 
+
-RemoveWASAPIDevice(const SDL_bool iscapture, LPCWSTR devid)
+void
 WASAPI_RemoveDevice(const SDL_bool iscapture, LPCWSTR devid)
 {
    DevIdList *i;
    DevIdList *next;
@ -269,23 +115,16 @@ RemoveWASAPIDevice(const SDL_bool iscapture, LPCWSTR devid)
    }
 }
-static void
+void
-AddWASAPIDevice(const SDL_bool iscapture, IMMDevice *device, LPCWSTR devid)
+WASAPI_AddDevice(const SDL_bool iscapture, const char *devname, LPCWSTR devid)
 {
    IPropertyStore *props = NULL;
    char *utf8dev = NULL;
    DevIdList *devidlist;
    PROPVARIANT var;
    /* You can have multiple endpoints on a device that are mutually exclusive ("Speakers" vs "Line Out" or whatever).
       In a perfect world, things that are unplugged won't be in this collection. The only gotcha is probably for
       phones and tablets, where you might have an internal speaker and a headphone jack and expect both to be
       available and switch automatically. (!!! FIXME...?) */
    /* PKEY_Device_FriendlyName gives you "Speakers (SoundBlaster Pro)" which drives me nuts. I'd rather it be
       "SoundBlaster Pro (Speakers)" but I guess that's developers vs users. Windows uses the FriendlyName in
       its own UIs, like Volume Control, etc. */
    /* see if we already have this one. */
    for (devidlist = deviceid_list; devidlist; devidlist = devidlist->next) {
        if (WStrEqual(devidlist->str, devid)) {
@ -308,61 +147,13 @@ AddWASAPIDevice(const SDL_bool iscapture, IMMDevice *device, LPCWSTR devid)
    devidlist->next = deviceid_list;
    deviceid_list = devidlist;
-    if (SUCCEEDED(IMMDevice_OpenPropertyStore(device, STGM_READ, &props))) {
+    SDL_AddAudioDevice(iscapture, devname, (void *) devid);
        PropVariantInit(&var);
        if (SUCCEEDED(IPropertyStore_GetValue(props, &SDL_PKEY_Device_FriendlyName, &var))) {
            utf8dev = WIN_StringToUTF8(var.pwszVal);
            if (utf8dev) {
                SDL_AddAudioDevice(iscapture, utf8dev, (void *) devid);
                SDL_free(utf8dev);
            }
        }
        PropVariantClear(&var);
        IPropertyStore_Release(props);
    }
 }
 static void
 EnumerateEndpoints(const SDL_bool iscapture)
 {
    IMMDeviceCollection *collection = NULL;
    UINT i, total;
    /* Note that WASAPI separates "adapter devices" from "audio endpoint devices"
       ...one adapter device ("SoundBlaster Pro") might have multiple endpoint devices ("Speakers", "Line-Out"). */
    if (FAILED(IMMDeviceEnumerator_EnumAudioEndpoints(enumerator, iscapture ? eCapture : eRender, DEVICE_STATE_ACTIVE, &collection))) {
        return;
    }
    if (FAILED(IMMDeviceCollection_GetCount(collection, &total))) {
        IMMDeviceCollection_Release(collection);
        return;
    }
    for (i = 0; i < total; i++) {
        IMMDevice *device = NULL;
        if (SUCCEEDED(IMMDeviceCollection_Item(collection, i, &device))) {
            LPWSTR devid = NULL;
            if (SUCCEEDED(IMMDevice_GetId(device, &devid))) {
                AddWASAPIDevice(iscapture, device, devid);
                CoTaskMemFree(devid);
            }
            IMMDevice_Release(device);
        }
    }
    IMMDeviceCollection_Release(collection);
 }
 static void
 WASAPI_DetectDevices(void)
 {
-    EnumerateEndpoints(SDL_FALSE);  /* playback */
+    WASAPI_EnumerateEndpoints();
    EnumerateEndpoints(SDL_TRUE);   /* capture */
    /* if this fails, we just won't get hotplug events. Carry on anyhow. */
    IMMDeviceEnumerator_RegisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *) &notification_client);
 }
 static int
@ -372,10 +163,11 @@ WASAPI_GetPendingBytes(_THIS)
    /* it's okay to fail here; we'll deal with failures in the audio thread. */
    /* FIXME: need a lock around checking this->hidden->client */
-    if (!this->hidden->client || FAILED(IAudioClient_GetCurrentPadding(this->hidden->client, &frames))) {
+    if (this->hidden->client != NULL) {  /* definitely activated? */
        if (FAILED(IAudioClient_GetCurrentPadding(this->hidden->client, &frames))) {
            return 0;  /* oh well. */
        }
-
+    }
    return ((int) frames) * this->hidden->framesize;
 }
@ -397,41 +189,9 @@ WasapiFailed(_THIS, const HRESULT err)
    return SDL_TRUE;
 }
-static int PrepWasapiDevice(_THIS, const int iscapture, IMMDevice *device);
+static int
-static void ReleaseWasapiDevice(_THIS);
+UpdateAudioStream(_THIS, const SDL_AudioSpec *oldspec)
 static SDL_bool
 RecoverWasapiDevice(_THIS)
 {
    const SDL_AudioSpec oldspec = this->spec;
    IMMDevice *device = NULL;
    HRESULT ret = S_OK;
    if (this->hidden->default_device_generation) {
        const EDataFlow dataflow = this->iscapture ? eCapture : eRender;
        ReleaseWasapiDevice(this);  /* dump the lost device's handles. */
        this->hidden->default_device_generation = SDL_AtomicGet(this->iscapture ?  &default_capture_generation : &default_playback_generation);
        ret = IMMDeviceEnumerator_GetDefaultAudioEndpoint(enumerator, dataflow, SDL_WASAPI_role, &device);
        if (FAILED(ret)) {
            return SDL_FALSE;  /* can't find a new default device! */
        }
    } else {
        device = this->hidden->device;
        this->hidden->device = NULL;  /* don't release this in ReleaseWasapiDevice(). */
        ReleaseWasapiDevice(this);  /* dump the lost device's handles. */
    }
    SDL_assert(device != NULL);
    /* this can fail for lots of reasons, but the most likely is we had a 
       non-default device that was disconnected, so we can't recover. Default
       devices try to reinitialize whatever the new default is, so it's more
       likely to carry on here, but this handles a non-default device that
       simply had its format changed in the Windows Control Panel. */
    if (PrepWasapiDevice(this, this->iscapture, device) == -1) {
        return SDL_FALSE;
    }
    /* Since WASAPI requires us to handle all audio conversion, and our
       device format might have changed, we might have to add/remove/change
       the audio stream that the higher level uses to convert data, so
@ -444,9 +204,9 @@ RecoverWasapiDevice(_THIS)
        /* no need to buffer/convert in an AudioStream! */
        SDL_FreeAudioStream(this->stream);
        this->stream = NULL;
-    } else if ( (oldspec.channels == this->spec.channels) &&
+    } else if ( (oldspec->channels == this->spec.channels) &&
-         (oldspec.format == this->spec.format) &&
+         (oldspec->format == this->spec.format) &&
-         (oldspec.freq == this->spec.freq) ) {
+         (oldspec->freq == this->spec.freq) ) {
        /* The existing audio stream is okay to keep using. */
    } else {
        /* replace the audiostream for new format */
@ -465,7 +225,7 @@ RecoverWasapiDevice(_THIS)
        }
        if (!this->stream) {
-            return SDL_FALSE;
+            return -1;
        }
    }
@ -473,13 +233,37 @@ RecoverWasapiDevice(_THIS)
    if (this->spec.size > this->work_buffer_len) {
        Uint8 *ptr = (Uint8 *) SDL_realloc(this->work_buffer, this->spec.size);
        if (ptr == NULL) {
-            SDL_OutOfMemory();
+            return SDL_OutOfMemory();
            return SDL_FALSE;
        }
        this->work_buffer = ptr;
        this->work_buffer_len = this->spec.size;
    }
    return 0;
 }
 static void ReleaseWasapiDevice(_THIS);
 static SDL_bool
 RecoverWasapiDevice(_THIS)
 {
    ReleaseWasapiDevice(this);  /* dump the lost device's handles. */
    if (this->hidden->default_device_generation) {
        this->hidden->default_device_generation = SDL_AtomicGet(this->iscapture ?  &WASAPI_DefaultCaptureGeneration : &WASAPI_DefaultPlaybackGeneration);
    }
    /* this can fail for lots of reasons, but the most likely is we had a
       non-default device that was disconnected, so we can't recover. Default
       devices try to reinitialize whatever the new default is, so it's more
       likely to carry on here, but this handles a non-default device that
       simply had its format changed in the Windows Control Panel. */
    if (WASAPI_ActivateDevice(this, SDL_TRUE) == -1) {
        SDL_OpenedAudioDeviceDisconnected(this);
        return SDL_FALSE;
    }
    this->hidden->device_lost = SDL_FALSE;
    return SDL_TRUE;  /* okay, carry on with new device details! */
@ -495,8 +279,12 @@ RecoverWasapiIfLost(_THIS)
        return SDL_FALSE;  /* already failed. */
    }
    if (!this->hidden->client) {
        return SDL_TRUE;  /* still waiting for activation. */
    }
    if (!lost && (generation > 0)) { /* is a default device? */
-        const int newgen = SDL_AtomicGet(this->iscapture ? &default_capture_generation : &default_playback_generation);
+        const int newgen = SDL_AtomicGet(this->iscapture ? &WASAPI_DefaultCaptureGeneration : &WASAPI_DefaultPlaybackGeneration);
        if (generation != newgen) {  /* the desired default device was changed, jump over to it. */
            lost = SDL_TRUE;
        }
@ -511,7 +299,7 @@ WASAPI_GetDeviceBuf(_THIS)
    /* get an endpoint buffer from WASAPI. */
    BYTE *buffer = NULL;
-    while (RecoverWasapiIfLost(this)) {
+    while (RecoverWasapiIfLost(this) && this->hidden->render) {
        if (!WasapiFailed(this, IAudioRenderClient_GetBuffer(this->hidden->render, this->spec.samples, &buffer))) {
            return (Uint8 *) buffer;
        }
@ -524,17 +312,18 @@ WASAPI_GetDeviceBuf(_THIS)
 static void
 WASAPI_PlayDevice(_THIS)
 {
    if (this->hidden->render != NULL) {  /* definitely activated? */
        /* WasapiFailed() will mark the device for reacquisition or removal elsewhere. */
        WasapiFailed(this, IAudioRenderClient_ReleaseBuffer(this->hidden->render, this->spec.samples, 0));
    }
 }
 static void
 WASAPI_WaitDevice(_THIS)
 {
    while (RecoverWasapiIfLost(this) && this->hidden->client) {
        const UINT32 maxpadding = this->spec.samples;
    while (RecoverWasapiIfLost(this)) {
        UINT32 padding = 0;
        if (!WasapiFailed(this, IAudioClient_GetCurrentPadding(this->hidden->client, &padding))) {
            if (padding <= maxpadding) {
                break;
@ -562,6 +351,14 @@ WASAPI_CaptureFromDevice(_THIS, void *buffer, int buflen)
        UINT32 frames = 0;
        DWORD flags = 0;
        /* uhoh, client isn't activated yet, just return silence. */
        if (!this->hidden->capture) {
            /* Delay so we run at about the speed that audio would be arriving. */
            SDL_Delay(((this->spec.samples * 1000) / this->spec.freq));
            SDL_memset(buffer, this->spec.silence, buflen);
            return buflen;
        }
        ret = IAudioCaptureClient_GetBuffer(this->hidden->capture, &ptr, &frames, &flags, NULL, NULL);
        if (ret != AUDCLNT_S_BUFFER_EMPTY) {
            WasapiFailed(this, ret); /* mark device lost/failed if necessary. */
@ -609,6 +406,10 @@ WASAPI_FlushCapture(_THIS)
    UINT32 frames = 0;
    DWORD flags = 0;
    if (!this->hidden->capture) {
        return;  /* not activated yet? */
    }
    /* just read until we stop getting packets, throwing them away. */
    while (SDL_TRUE) {
        const HRESULT ret = IAudioCaptureClient_GetBuffer(this->hidden->capture, &ptr, &frames, &flags, NULL, NULL);
@ -646,30 +447,49 @@ ReleaseWasapiDevice(_THIS)
        this->hidden->waveformat = NULL;
    }
    if (this->hidden->device) {
        IMMDevice_Release(this->hidden->device);
        this->hidden->device = NULL;
    }
    if (this->hidden->capturestream) {
        SDL_FreeAudioStream(this->hidden->capturestream);
        this->hidden->capturestream = NULL;
    }
    if (this->hidden->activation_handler) {
        WASAPI_PlatformDeleteActivationHandler(this->hidden->activation_handler);
        this->hidden->activation_handler = NULL;
    }
 }
 static void
 WASAPI_CloseDevice(_THIS)
 {
    WASAPI_UnrefDevice(this);
 }
 void
 WASAPI_RefDevice(_THIS)
 {
    SDL_AtomicIncRef(&this->hidden->refcount);
 }
 void
 WASAPI_UnrefDevice(_THIS)
 {
    if (!SDL_AtomicDecRef(&this->hidden->refcount)) {
        return;
    }
    /* actual closing happens here. */
    /* don't touch this->hidden->task in here; it has to be reverted from
       our callback thread. We do that in WASAPI_ThreadDeinit().
       (likewise for this->hidden->coinitialized). */
    ReleaseWasapiDevice(this);
    SDL_free(this->hidden->devid);
    SDL_free(this->hidden);
 }
-
+/* This is called once a device is activated, possibly asynchronously. */
-static int
+int
-PrepWasapiDevice(_THIS, const int iscapture, IMMDevice *device)
+WASAPI_PrepDevice(_THIS, const SDL_bool updatestream)
 {
    /* !!! FIXME: we could request an exclusive mode stream, which is lower latency;
       !!!  it will write into the kernel's audio buffer directly instead of
@ -682,10 +502,11 @@ PrepWasapiDevice(_THIS, const int iscapture, IMMDevice *device)
       !!!  wins actually look like. Maybe add a hint to force exclusive mode at
       !!!  some point. To be sure, defaulting to shared mode is the right thing to
       !!!  do in any case. */
    const SDL_AudioSpec oldspec = this->spec;
    const AUDCLNT_SHAREMODE sharemode = AUDCLNT_SHAREMODE_SHARED;
    UINT32 bufsize = 0;  /* this is in sample frames, not samples, not bytes. */
    REFERENCE_TIME duration = 0;
-    IAudioClient *client = NULL;
+    IAudioClient *client = this->hidden->client;
    IAudioRenderClient *render = NULL;
    IAudioCaptureClient *capture = NULL;
    WAVEFORMATEX *waveformat = NULL;
@ -694,15 +515,7 @@ PrepWasapiDevice(_THIS, const int iscapture, IMMDevice *device)
    SDL_bool valid_format = SDL_FALSE;
    HRESULT ret = S_OK;
    this->hidden->device = device;
    ret = IMMDevice_Activate(device, &SDL_IID_IAudioClient, CLSCTX_ALL, NULL, (void **) &client);
    if (FAILED(ret)) {
        return WIN_SetErrorFromHRESULT("WASAPI can't activate audio endpoint", ret);
    }
    SDL_assert(client != NULL);
    this->hidden->client = client;
    ret = IAudioClient_GetMixFormat(client, &waveformat);
    if (FAILED(ret)) {
@ -763,7 +576,7 @@ PrepWasapiDevice(_THIS, const int iscapture, IMMDevice *device)
    }
    this->spec.samples = (Uint16) bufsize;
-    if (!iscapture) {
+    if (!this->iscapture) {
        this->spec.samples /= 2;  /* fill half of the DMA buffer on each run. */
    }
@ -772,7 +585,7 @@ PrepWasapiDevice(_THIS, const int iscapture, IMMDevice *device)
    this->hidden->framesize = (SDL_AUDIO_BITSIZE(this->spec.format) / 8) * this->spec.channels;
-    if (iscapture) {
+    if (this->iscapture) {
        this->hidden->capturestream = SDL_NewAudioStream(this->spec.format, this->spec.channels, this->spec.freq, this->spec.format, this->spec.channels, this->spec.freq);
        if (!this->hidden->capturestream) {
            return -1;  /* already set SDL_Error */
@ -805,15 +618,20 @@ PrepWasapiDevice(_THIS, const int iscapture, IMMDevice *device)
        }
    }
    if (updatestream) {
        if (UpdateAudioStream(this, &oldspec) == -1) {
            return -1;
        }
    }
    return 0;  /* good to go. */
 }
 static int
 WASAPI_OpenDevice(_THIS, void *handle, const char *devname, int iscapture)
 {
-    const SDL_bool is_default_device = (handle == NULL);
+    LPCWSTR devid = (LPCWSTR) handle;
    IMMDevice *device = NULL;
    HRESULT ret = S_OK;
    /* Initialize all variables that we clean on shutdown */
    this->hidden = (struct SDL_PrivateAudioData *)
@ -823,49 +641,42 @@ WASAPI_OpenDevice(_THIS, void *handle, const char *devname, int iscapture)
    }
    SDL_zerop(this->hidden);
-    if (is_default_device) {
+    WASAPI_RefDevice(this);   /* so CloseDevice() will unref to zero. */
-        const EDataFlow dataflow = iscapture ? eCapture : eRender;
+
-        this->hidden->default_device_generation = SDL_AtomicGet(iscapture ? &default_capture_generation : &default_playback_generation);
+    if (!devid) {  /* is default device? */
-        ret = IMMDeviceEnumerator_GetDefaultAudioEndpoint(enumerator, dataflow, SDL_WASAPI_role, &device);
+        this->hidden->default_device_generation = SDL_AtomicGet(iscapture ? &WASAPI_DefaultCaptureGeneration : &WASAPI_DefaultPlaybackGeneration);
    } else {
-        ret = IMMDeviceEnumerator_GetDevice(enumerator, (LPCWSTR) handle, &device);
+        this->hidden->devid = WStrDupe(devid);
        if (!this->hidden->devid) {
            return SDL_OutOfMemory();
        }
    }
-    if (FAILED(ret)) {
+    if (WASAPI_ActivateDevice(this, SDL_FALSE) == -1) {
-        return WIN_SetErrorFromHRESULT("WASAPI can't find requested audio endpoint", ret);
+        return -1;  /* already set error. */
    }
-    SDL_assert(device != NULL);
+    /* Ready, but waiting for async device activation.
-    return PrepWasapiDevice(this, iscapture, device);
+       Until activation is successful, we will report silence from capture
       devices and ignore data on playback devices.
       Also, since we don't know the _actual_ device format until after
       activation, we let the app have whatever it asks for. We set up
       an SDL_AudioStream to convert, if necessary, once the activation
       completes. */
    return 0;
 }
 static void
 WASAPI_ThreadInit(_THIS)
 {
-    /* this thread uses COM. */
+    WASAPI_PlatformThreadInit(this);
    if (SUCCEEDED(WIN_CoInitialize())) {    /* can't report errors, hope it worked! */
        this->hidden->coinitialized = SDL_TRUE;
    }
    /* Set this thread to very high "Pro Audio" priority. */
    if (pAvSetMmThreadCharacteristicsW) {
        DWORD idx = 0;
        this->hidden->task = pAvSetMmThreadCharacteristicsW(TEXT("Pro Audio"), &idx);
    }
 }
 static void
 WASAPI_ThreadDeinit(_THIS)
 {
-    /* Set this thread to very high "Pro Audio" priority. */
+    WASAPI_PlatformThreadDeinit(this);
    if (this->hidden->task && pAvRevertMmThreadCharacteristics) {
        pAvRevertMmThreadCharacteristics(this->hidden->task);
        this->hidden->task = NULL;
    }
    if (this->hidden->coinitialized) {
        WIN_CoUninitialize();
    }
 }
 static void
@ -874,21 +685,7 @@ WASAPI_Deinitialize(void)
    DevIdList *devidlist;
    DevIdList *next;
-    if (enumerator) {
+    WASAPI_PlatformDeinit();
        IMMDeviceEnumerator_UnregisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *) &notification_client);
        IMMDeviceEnumerator_Release(enumerator);
        enumerator = NULL;
    }
    #ifndef __WINRT__
    if (libavrt) {
        FreeLibrary(libavrt);
        libavrt = NULL;
    }
    #endif
    pAvSetMmThreadCharacteristicsW = NULL;
    pAvRevertMmThreadCharacteristics = NULL;
    for (devidlist = deviceid_list; devidlist; devidlist = next) {
        next = devidlist->next;
@ -896,51 +693,23 @@ WASAPI_Deinitialize(void)
        SDL_free(devidlist);
    }
    deviceid_list = NULL;
    WIN_CoUninitialize();
 }
 static int
 WASAPI_Init(SDL_AudioDriverImpl * impl)
 {
-    HRESULT ret;
+    SDL_AtomicSet(&WASAPI_DefaultPlaybackGeneration, 1);
    SDL_AtomicSet(&WASAPI_DefaultCaptureGeneration, 1);
-    /* just skip the discussion with COM here. */
+    if (WASAPI_PlatformInit() == -1) {
    if (!WIN_IsWindowsVistaOrGreater()) {
        SDL_SetError("WASAPI support requires Windows Vista or later");
        return 0;
    }
    SDL_AtomicSet(&default_playback_generation, 1);
    SDL_AtomicSet(&default_capture_generation, 1);
    if (FAILED(WIN_CoInitialize())) {
        SDL_SetError("WASAPI: CoInitialize() failed");
        return 0;
    }
    ret = CoCreateInstance(&SDL_CLSID_MMDeviceEnumerator, NULL, CLSCTX_INPROC_SERVER, &SDL_IID_IMMDeviceEnumerator, (LPVOID) &enumerator);
    if (FAILED(ret)) {
        WIN_CoUninitialize();
        WIN_SetErrorFromHRESULT("WASAPI CoCreateInstance(MMDeviceEnumerator)", ret);
        return 0;  /* oh well. */
    }
    #ifdef __WINRT__
    pAvSetMmThreadCharacteristicsW = AvSetMmThreadCharacteristicsW;
    pAvRevertMmThreadCharacteristics = AvRevertMmThreadCharacteristics;
    #else
    libavrt = LoadLibraryW(L"avrt.dll");  /* this library is available in Vista and later. No WinXP, so have to LoadLibrary to use it for now! */
    if (libavrt) {
        pAvSetMmThreadCharacteristicsW = (pfnAvSetMmThreadCharacteristicsW) GetProcAddress(libavrt, "AvSetMmThreadCharacteristicsW");
        pAvRevertMmThreadCharacteristics = (pfnAvRevertMmThreadCharacteristics) GetProcAddress(libavrt, "AvRevertMmThreadCharacteristics");
    }
    #endif
    /* Set the function pointers */
    impl->DetectDevices = WASAPI_DetectDevices;
    impl->ThreadInit = WASAPI_ThreadInit;
    impl->ThreadDeinit = WASAPI_ThreadDeinit;
    impl->BeginLoopIteration = WASAPI_BeginLoopIteration;
    impl->OpenDevice = WASAPI_OpenDevice;
    impl->PlayDevice = WASAPI_PlayDevice;
    impl->WaitDevice = WASAPI_WaitDevice;
--- a/src/audio/wasapi/SDL_wasapi.h
+++ b/src/audio/wasapi/SDL_wasapi.h
@ -23,14 +23,23 @@
 #ifndef SDL_wasapi_h_
 #define SDL_wasapi_h_
 #ifdef __cplusplus
 extern "C" {
 #endif
 #include "../SDL_sysaudio.h"
 /* Hidden "this" pointer for the audio functions */
 #ifdef __cplusplus
 #define _THIS SDL_AudioDevice *_this
 #else
 #define _THIS SDL_AudioDevice *this
 #endif
 struct SDL_PrivateAudioData
 {
-    IMMDevice *device;
+    SDL_atomic_t refcount;
    WCHAR *devid;
    WAVEFORMATEX *waveformat;
    IAudioClient *client;
    IAudioRenderClient *render;
@ -41,8 +50,35 @@ struct SDL_PrivateAudioData
    int framesize;
    int default_device_generation;
    SDL_bool device_lost;
    void *activation_handler;
    SDL_atomic_t just_activated;
 };
 /* these increment as default devices change. Opened default devices pick up changes in their threads. */
 extern SDL_atomic_t WASAPI_DefaultPlaybackGeneration;
 extern SDL_atomic_t WASAPI_DefaultCaptureGeneration;
 /* win32 and winrt implementations call into these. */
 int WASAPI_PrepDevice(_THIS, const SDL_bool updatestream);
 void WASAPI_RefDevice(_THIS);
 void WASAPI_UnrefDevice(_THIS);
 void WASAPI_AddDevice(const SDL_bool iscapture, const char *devname, LPCWSTR devid);
 void WASAPI_RemoveDevice(const SDL_bool iscapture, LPCWSTR devid);
 /* These are functions that are implemented differently for Windows vs WinRT. */
 int WASAPI_PlatformInit(void);
 void WASAPI_PlatformDeinit(void);
 void WASAPI_EnumerateEndpoints(void);
 int WASAPI_ActivateDevice(_THIS, const SDL_bool isrecovery);
 void WASAPI_PlatformThreadInit(_THIS);
 void WASAPI_PlatformThreadDeinit(_THIS);
 void WASAPI_PlatformDeleteActivationHandler(void *handler);
 void WASAPI_BeginLoopIteration(_THIS);
 #ifdef __cplusplus
 }
 #endif
 #endif /* SDL_wasapi_h_ */
 /* vi: set ts=4 sw=4 expandtab: */
--- a/src/audio/wasapi/SDL_wasapi_win32.c
+++ b/src/audio/wasapi/SDL_wasapi_win32.c
@ -0,0 +1,418 @@
 /*
  Simple DirectMedia Layer
  Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
 */
 #include "../../SDL_internal.h"
 /* This is code that Windows uses to talk to WASAPI-related system APIs.
   This is for non-WinRT desktop apps. The C++/CX implementation of these
   functions, exclusive to WinRT, are in SDL_wasapi_winrt.cpp.
   The code in SDL_wasapi.c is used by both standard Windows and WinRT builds
   to deal with audio and calls into these functions. */
 #if SDL_AUDIO_DRIVER_WASAPI && !defined(__WINRT__)
 #include "../../core/windows/SDL_windows.h"
 #include "SDL_audio.h"
 #include "SDL_timer.h"
 #include "../SDL_audio_c.h"
 #include "../SDL_sysaudio.h"
 #include "SDL_assert.h"
 #include "SDL_log.h"
 #define COBJMACROS
 #include <mmdeviceapi.h>
 #include <audioclient.h>
 #include "SDL_wasapi.h"
 static const ERole SDL_WASAPI_role = eConsole;  /* !!! FIXME: should this be eMultimedia? Should be a hint? */
 /* This is global to the WASAPI target, to handle hotplug and default device lookup. */
 static IMMDeviceEnumerator *enumerator = NULL;
 /* PropVariantInit() is an inline function/macro in PropIdl.h that calls the C runtime's memset() directly. Use ours instead, to avoid dependency. */
 #ifdef PropVariantInit
 #undef PropVariantInit
 #endif
 #define PropVariantInit(p) SDL_zerop(p)
 /* handle to Avrt.dll--Vista and later!--for flagging the callback thread as "Pro Audio" (low latency). */
 static HMODULE libavrt = NULL;
 typedef HANDLE(WINAPI *pfnAvSetMmThreadCharacteristicsW)(LPWSTR, LPDWORD);
 typedef BOOL(WINAPI *pfnAvRevertMmThreadCharacteristics)(HANDLE);
 static pfnAvSetMmThreadCharacteristicsW pAvSetMmThreadCharacteristicsW = NULL;
 static pfnAvRevertMmThreadCharacteristics pAvRevertMmThreadCharacteristics = NULL;
 /* Some GUIDs we need to know without linking to libraries that aren't available before Vista. */
 static const CLSID SDL_CLSID_MMDeviceEnumerator = { 0xbcde0395, 0xe52f, 0x467c,{ 0x8e, 0x3d, 0xc4, 0x57, 0x92, 0x91, 0x69, 0x2e } };
 static const IID SDL_IID_IMMDeviceEnumerator = { 0xa95664d2, 0x9614, 0x4f35,{ 0xa7, 0x46, 0xde, 0x8d, 0xb6, 0x36, 0x17, 0xe6 } };
 static const IID SDL_IID_IMMNotificationClient = { 0x7991eec9, 0x7e89, 0x4d85,{ 0x83, 0x90, 0x6c, 0x70, 0x3c, 0xec, 0x60, 0xc0 } };
 static const IID SDL_IID_IMMEndpoint = { 0x1be09788, 0x6894, 0x4089,{ 0x85, 0x86, 0x9a, 0x2a, 0x6c, 0x26, 0x5a, 0xc5 } };
 static const IID SDL_IID_IAudioClient = { 0x1cb9ad4c, 0xdbfa, 0x4c32,{ 0xb1, 0x78, 0xc2, 0xf5, 0x68, 0xa7, 0x03, 0xb2 } };
 static const PROPERTYKEY SDL_PKEY_Device_FriendlyName = { { 0xa45c254e, 0xdf1c, 0x4efd,{ 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0, } }, 14 };
 static char *
 GetWasapiDeviceName(IMMDevice *device)
 {
    /* PKEY_Device_FriendlyName gives you "Speakers (SoundBlaster Pro)" which drives me nuts. I'd rather it be
       "SoundBlaster Pro (Speakers)" but I guess that's developers vs users. Windows uses the FriendlyName in
       its own UIs, like Volume Control, etc. */
    char *utf8dev = NULL;
    IPropertyStore *props = NULL;
    if (SUCCEEDED(IMMDevice_OpenPropertyStore(device, STGM_READ, &props))) {
        PROPVARIANT var;
        PropVariantInit(&var);
        if (SUCCEEDED(IPropertyStore_GetValue(props, &SDL_PKEY_Device_FriendlyName, &var))) {
            utf8dev = WIN_StringToUTF8(var.pwszVal);
        }
        PropVariantClear(&var);
        IPropertyStore_Release(props);
    }
    return utf8dev;
 }
 /* We need a COM subclass of IMMNotificationClient for hotplug support, which is
   easy in C++, but we have to tapdance more to make work in C.
   Thanks to this page for coaching on how to make this work:
     https://www.codeproject.com/Articles/13601/COM-in-plain-C */
 typedef struct SDLMMNotificationClient
 {
    const IMMNotificationClientVtbl *lpVtbl;
    SDL_atomic_t refcount;
 } SDLMMNotificationClient;
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_QueryInterface(IMMNotificationClient *this, REFIID iid, void **ppv)
 {
    if ((WIN_IsEqualIID(iid, &IID_IUnknown)) || (WIN_IsEqualIID(iid, &SDL_IID_IMMNotificationClient)))
    {
        *ppv = this;
        this->lpVtbl->AddRef(this);
        return S_OK;
    }
    *ppv = NULL;
    return E_NOINTERFACE;
 }
 static ULONG STDMETHODCALLTYPE
 SDLMMNotificationClient_AddRef(IMMNotificationClient *ithis)
 {
    SDLMMNotificationClient *this = (SDLMMNotificationClient *) ithis;
    return (ULONG) (SDL_AtomicIncRef(&this->refcount) + 1);
 }
 static ULONG STDMETHODCALLTYPE
 SDLMMNotificationClient_Release(IMMNotificationClient *ithis)
 {
    /* this is a static object; we don't ever free it. */
    SDLMMNotificationClient *this = (SDLMMNotificationClient *) ithis;
    const ULONG retval = SDL_AtomicDecRef(&this->refcount);
    if (retval == 0) {
        SDL_AtomicSet(&this->refcount, 0);  /* uhh... */
        return 0;
    }
    return retval - 1;
 }
 /* These are the entry points called when WASAPI device endpoints change. */
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_OnDefaultDeviceChanged(IMMNotificationClient *ithis, EDataFlow flow, ERole role, LPCWSTR pwstrDeviceId)
 {
    if (role != SDL_WASAPI_role) {
        return S_OK;  /* ignore it. */
    }
    /* Increment the "generation," so opened devices will pick this up in their threads. */
    switch (flow) {
        case eRender:
            SDL_AtomicAdd(&WASAPI_DefaultPlaybackGeneration, 1);
            break;
        case eCapture:
            SDL_AtomicAdd(&WASAPI_DefaultCaptureGeneration, 1);
            break;
        case eAll:
            SDL_AtomicAdd(&WASAPI_DefaultPlaybackGeneration, 1);
            SDL_AtomicAdd(&WASAPI_DefaultCaptureGeneration, 1);
            break;
        default:
            SDL_assert(!"uhoh, unexpected OnDefaultDeviceChange flow!");
            break;
    }
    return S_OK;
 }
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_OnDeviceAdded(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId)
 {
    /* we ignore this; devices added here then progress to ACTIVE, if appropriate, in 
       OnDeviceStateChange, making that a better place to deal with device adds. More 
       importantly: the first time you plug in a USB audio device, this callback will 
       fire, but when you unplug it, it isn't removed (it's state changes to NOTPRESENT).
       Plugging it back in won't fire this callback again. */
    return S_OK;
 }
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_OnDeviceRemoved(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId)
 {
    /* See notes in OnDeviceAdded handler about why we ignore this. */
    return S_OK;
 }
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_OnDeviceStateChanged(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId, DWORD dwNewState)
 {
    SDLMMNotificationClient *this = (SDLMMNotificationClient *) ithis;
    IMMDevice *device = NULL;
    if (SUCCEEDED(IMMDeviceEnumerator_GetDevice(enumerator, pwstrDeviceId, &device))) {
        IMMEndpoint *endpoint = NULL;
        if (SUCCEEDED(IMMDevice_QueryInterface(device, &SDL_IID_IMMEndpoint, (void **) &endpoint))) {
            EDataFlow flow;
            if (SUCCEEDED(IMMEndpoint_GetDataFlow(endpoint, &flow))) {
                const SDL_bool iscapture = (flow == eCapture);
                if (dwNewState == DEVICE_STATE_ACTIVE) {
                    char *utf8dev = GetWasapiDeviceName(device);
                    if (utf8dev) {
                        WASAPI_AddDevice(iscapture, utf8dev, pwstrDeviceId);
                        SDL_free(utf8dev);
                    }
                } else {
                    WASAPI_RemoveDevice(iscapture, pwstrDeviceId);
                }
            }
            IMMEndpoint_Release(endpoint);
        }
        IMMDevice_Release(device);
    }
    return S_OK;
 }
 static HRESULT STDMETHODCALLTYPE
 SDLMMNotificationClient_OnPropertyValueChanged(IMMNotificationClient *this, LPCWSTR pwstrDeviceId, const PROPERTYKEY key)
 {
    return S_OK;  /* we don't care about these. */
 }
 static const IMMNotificationClientVtbl notification_client_vtbl = {
    SDLMMNotificationClient_QueryInterface,
    SDLMMNotificationClient_AddRef,
    SDLMMNotificationClient_Release,
    SDLMMNotificationClient_OnDeviceStateChanged,
    SDLMMNotificationClient_OnDeviceAdded,
    SDLMMNotificationClient_OnDeviceRemoved,
    SDLMMNotificationClient_OnDefaultDeviceChanged,
    SDLMMNotificationClient_OnPropertyValueChanged
 };
 static SDLMMNotificationClient notification_client = { &notification_client_vtbl, 1 };
 int
 WASAPI_PlatformInit(void)
 {
    HRESULT ret;
    /* just skip the discussion with COM here. */
    if (!WIN_IsWindowsVistaOrGreater()) {
        return SDL_SetError("WASAPI support requires Windows Vista or later");
    }
    if (FAILED(WIN_CoInitialize())) {
        return SDL_SetError("WASAPI: CoInitialize() failed");
    }
    ret = CoCreateInstance(&SDL_CLSID_MMDeviceEnumerator, NULL, CLSCTX_INPROC_SERVER, &SDL_IID_IMMDeviceEnumerator, (LPVOID) &enumerator);
    if (FAILED(ret)) {
        WIN_CoUninitialize();
        return WIN_SetErrorFromHRESULT("WASAPI CoCreateInstance(MMDeviceEnumerator)", ret);
    }
    libavrt = LoadLibraryW(L"avrt.dll");  /* this library is available in Vista and later. No WinXP, so have to LoadLibrary to use it for now! */
    if (libavrt) {
        pAvSetMmThreadCharacteristicsW = (pfnAvSetMmThreadCharacteristicsW) GetProcAddress(libavrt, "AvSetMmThreadCharacteristicsW");
        pAvRevertMmThreadCharacteristics = (pfnAvRevertMmThreadCharacteristics) GetProcAddress(libavrt, "AvRevertMmThreadCharacteristics");
    }
    return 0;
 }
 void
 WASAPI_PlatformDeinit(void)
 {
    if (enumerator) {
        IMMDeviceEnumerator_UnregisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *) &notification_client);
        IMMDeviceEnumerator_Release(enumerator);
        enumerator = NULL;
    }
    if (libavrt) {
        FreeLibrary(libavrt);
        libavrt = NULL;
    }
    pAvSetMmThreadCharacteristicsW = NULL;
    pAvRevertMmThreadCharacteristics = NULL;
    WIN_CoUninitialize();
 }
 void
 WASAPI_PlatformThreadInit(_THIS)
 {
    /* this thread uses COM. */
    if (SUCCEEDED(WIN_CoInitialize())) {    /* can't report errors, hope it worked! */
        this->hidden->coinitialized = SDL_TRUE;
    }
    /* Set this thread to very high "Pro Audio" priority. */
    if (pAvSetMmThreadCharacteristicsW) {
        DWORD idx = 0;
        this->hidden->task = pAvSetMmThreadCharacteristicsW(TEXT("Pro Audio"), &idx);
    }
 }
 void
 WASAPI_PlatformThreadDeinit(_THIS)
 {
    /* Set this thread back to normal priority. */
    if (this->hidden->task && pAvRevertMmThreadCharacteristics) {
        pAvRevertMmThreadCharacteristics(this->hidden->task);
        this->hidden->task = NULL;
    }
    if (this->hidden->coinitialized) {
        WIN_CoUninitialize();
        this->hidden->coinitialized = SDL_FALSE;
    }
 }
 int
 WASAPI_ActivateDevice(_THIS, const SDL_bool isrecovery)
 {
    LPCWSTR devid = this->hidden->devid;
    IMMDevice *device = NULL;
    HRESULT ret;
    if (devid == NULL) {
        const EDataFlow dataflow = this->iscapture ? eCapture : eRender;
        ret = IMMDeviceEnumerator_GetDefaultAudioEndpoint(enumerator, dataflow, SDL_WASAPI_role, &device);
    } else {
        ret = IMMDeviceEnumerator_GetDevice(enumerator, devid, &device);
    }
    if (FAILED(ret)) {
        SDL_assert(device == NULL);
        this->hidden->client = NULL;
        return WIN_SetErrorFromHRESULT("WASAPI can't find requested audio endpoint", ret);
    }
    /* this is not async in standard win32, yay! */
    ret = IMMDevice_Activate(device, &SDL_IID_IAudioClient, CLSCTX_ALL, NULL, (void **) &this->hidden->client);
    IMMDevice_Release(device);
    if (FAILED(ret)) {
        SDL_assert(this->hidden->client == NULL);
        return WIN_SetErrorFromHRESULT("WASAPI can't activate audio endpoint", ret);
    }
    SDL_assert(this->hidden->client != NULL);
    if (WASAPI_PrepDevice(this, isrecovery) == -1) {   /* not async, fire it right away. */
        return -1;
    }
    return 0;  /* good to go. */
 }
 static void
 WASAPI_EnumerateEndpointsForFlow(const SDL_bool iscapture)
 {
    IMMDeviceCollection *collection = NULL;
    UINT i, total;
    /* Note that WASAPI separates "adapter devices" from "audio endpoint devices"
       ...one adapter device ("SoundBlaster Pro") might have multiple endpoint devices ("Speakers", "Line-Out"). */
    if (FAILED(IMMDeviceEnumerator_EnumAudioEndpoints(enumerator, iscapture ? eCapture : eRender, DEVICE_STATE_ACTIVE, &collection))) {
        return;
    }
    if (FAILED(IMMDeviceCollection_GetCount(collection, &total))) {
        IMMDeviceCollection_Release(collection);
        return;
    }
    for (i = 0; i < total; i++) {
        IMMDevice *device = NULL;
        if (SUCCEEDED(IMMDeviceCollection_Item(collection, i, &device))) {
            LPWSTR devid = NULL;
            if (SUCCEEDED(IMMDevice_GetId(device, &devid))) {
                char *devname = GetWasapiDeviceName(device);
                if (devname) {
                    WASAPI_AddDevice(iscapture, devname, devid);
                    SDL_free(devname);
                }
                CoTaskMemFree(devid);
            }
            IMMDevice_Release(device);
        }
    }
    IMMDeviceCollection_Release(collection);
 }
 void
 WASAPI_EnumerateEndpoints(void)
 {
    WASAPI_EnumerateEndpointsForFlow(SDL_FALSE);  /* playback */
    WASAPI_EnumerateEndpointsForFlow(SDL_TRUE);  /* capture */
    /* if this fails, we just won't get hotplug events. Carry on anyhow. */
    IMMDeviceEnumerator_RegisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *) &notification_client);
 }
 void
 WASAPI_PlatformDeleteActivationHandler(void *handler)
 {
    /* not asynchronous. */
    SDL_assert(!"This function should have only be called on WinRT.");
 }
 void
 WASAPI_BeginLoopIteration(_THIS)
 {
    /* no-op. */
 }
 #endif  /* SDL_AUDIO_DRIVER_WASAPI && !defined(__WINRT__) */
 /* vi: set ts=4 sw=4 expandtab: */
--- a/src/audio/wasapi/SDL_wasapi_winrt.cpp
+++ b/src/audio/wasapi/SDL_wasapi_winrt.cpp
@ -0,0 +1,276 @@
 /*
  Simple DirectMedia Layer
  Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
 */
 #include "../../SDL_internal.h"
 // This is C++/CX code that the WinRT port uses to talk to WASAPI-related
 //  system APIs. The C implementation of these functions, for non-WinRT apps,
 //  is in SDL_wasapi_win32.c. The code in SDL_wasapi.c is used by both standard
 //  Windows and WinRT builds to deal with audio and calls into these functions.
 #if SDL_AUDIO_DRIVER_WASAPI && defined(__WINRT__)
 #include <Windows.h>
 #include <windows.ui.core.h>
 #include <windows.devices.enumeration.h>
 #include <windows.media.devices.h>
 #include <wrl/implements.h>
 extern "C" {
 #include "../../core/windows/SDL_windows.h"
 #include "SDL_audio.h"
 #include "SDL_timer.h"
 #include "../SDL_audio_c.h"
 #include "../SDL_sysaudio.h"
 #include "SDL_assert.h"
 #include "SDL_log.h"
 }
 #define COBJMACROS
 #include <mmdeviceapi.h>
 #include <audioclient.h>
 #include "SDL_wasapi.h"
 using namespace Windows::Devices::Enumeration;
 using namespace Windows::Media::Devices;
 using namespace Windows::Foundation;
 using namespace Microsoft::WRL;
 class SDL_WasapiDeviceEventHandler
 {
 public:
    SDL_WasapiDeviceEventHandler(const SDL_bool _iscapture);
    ~SDL_WasapiDeviceEventHandler();
    void OnDeviceAdded(DeviceWatcher^ sender, DeviceInformation^ args);
    void OnDeviceRemoved(DeviceWatcher^ sender, DeviceInformationUpdate^ args);
    void OnDeviceUpdated(DeviceWatcher^ sender, DeviceInformationUpdate^ args);
    void OnDefaultRenderDeviceChanged(Platform::Object^ sender, DefaultAudioRenderDeviceChangedEventArgs^ args);
    void OnDefaultCaptureDeviceChanged(Platform::Object^ sender, DefaultAudioCaptureDeviceChangedEventArgs^ args);
 private:
    const SDL_bool iscapture;
    DeviceWatcher^ watcher;
    Windows::Foundation::EventRegistrationToken added_handler;
    Windows::Foundation::EventRegistrationToken removed_handler;
    Windows::Foundation::EventRegistrationToken updated_handler;
    Windows::Foundation::EventRegistrationToken default_changed_handler;
 };
 SDL_WasapiDeviceEventHandler::SDL_WasapiDeviceEventHandler(const SDL_bool _iscapture)
    : iscapture(_iscapture)
    , watcher(DeviceInformation::CreateWatcher(_iscapture ? DeviceClass::AudioCapture : DeviceClass::AudioRender))
 {
    if (!watcher)
        return;  // uhoh.
    // !!! FIXME: this doesn't need a lambda here, I think, if I make SDL_WasapiDeviceEventHandler a proper C++/CX class. --ryan.
    added_handler = watcher->Added += ref new TypedEventHandler<DeviceWatcher^, DeviceInformation^>([this](DeviceWatcher^ sender, DeviceInformation^ args) { OnDeviceAdded(sender, args); } );
    removed_handler = watcher->Removed += ref new TypedEventHandler<DeviceWatcher^, DeviceInformationUpdate^>([this](DeviceWatcher^ sender, DeviceInformationUpdate^ args) { OnDeviceRemoved(sender, args); } );
    updated_handler = watcher->Updated += ref new TypedEventHandler<DeviceWatcher^, DeviceInformationUpdate^>([this](DeviceWatcher^ sender, DeviceInformationUpdate^ args) { OnDeviceUpdated(sender, args); } );
    if (iscapture) {
        default_changed_handler = MediaDevice::DefaultAudioCaptureDeviceChanged += ref new TypedEventHandler<Platform::Object^, DefaultAudioCaptureDeviceChangedEventArgs^>([this](Platform::Object^ sender, DefaultAudioCaptureDeviceChangedEventArgs^ args) { OnDefaultCaptureDeviceChanged(sender, args); } );
    } else {
        default_changed_handler = MediaDevice::DefaultAudioRenderDeviceChanged += ref new TypedEventHandler<Platform::Object^, DefaultAudioRenderDeviceChangedEventArgs^>([this](Platform::Object^ sender, DefaultAudioRenderDeviceChangedEventArgs^ args) { OnDefaultRenderDeviceChanged(sender, args); } );
    }
    watcher->Start();
 }
 SDL_WasapiDeviceEventHandler::~SDL_WasapiDeviceEventHandler()
 {
    if (watcher) {
        watcher->Added -= added_handler;
        watcher->Removed -= removed_handler;
        watcher->Updated -= updated_handler;
        watcher->Stop();
        watcher = nullptr;
    }
    if (iscapture) {
        MediaDevice::DefaultAudioCaptureDeviceChanged -= default_changed_handler;
    } else {
        MediaDevice::DefaultAudioRenderDeviceChanged -= default_changed_handler;
    }
 }
 void
 SDL_WasapiDeviceEventHandler::OnDeviceAdded(DeviceWatcher^ sender, DeviceInformation^ info)
 {
    SDL_assert(sender == this->watcher);
    char *utf8dev = WIN_StringToUTF8(info->Name->Data());
    if (utf8dev) {
        WASAPI_AddDevice(this->iscapture, utf8dev, info->Id->Data());
        SDL_free(utf8dev);
    }
 }
 void
 SDL_WasapiDeviceEventHandler::OnDeviceRemoved(DeviceWatcher^ sender, DeviceInformationUpdate^ info)
 {
    SDL_assert(sender == this->watcher);
    WASAPI_RemoveDevice(this->iscapture, info->Id->Data());
 }
 void
 SDL_WasapiDeviceEventHandler::OnDeviceUpdated(DeviceWatcher^ sender, DeviceInformationUpdate^ args)
 {
    SDL_assert(sender == this->watcher);
 }
 void
 SDL_WasapiDeviceEventHandler::OnDefaultRenderDeviceChanged(Platform::Object^ sender, DefaultAudioRenderDeviceChangedEventArgs^ args)
 {
    SDL_assert(this->iscapture);
    SDL_AtomicAdd(&WASAPI_DefaultPlaybackGeneration, 1);
 }
 void
 SDL_WasapiDeviceEventHandler::OnDefaultCaptureDeviceChanged(Platform::Object^ sender, DefaultAudioCaptureDeviceChangedEventArgs^ args)
 {
    SDL_assert(!this->iscapture);
    SDL_AtomicAdd(&WASAPI_DefaultCaptureGeneration, 1);
 }
 static SDL_WasapiDeviceEventHandler *playback_device_event_handler;
 static SDL_WasapiDeviceEventHandler *capture_device_event_handler;
 int WASAPI_PlatformInit(void)
 {
    return 0;
 }
 void WASAPI_PlatformDeinit(void)
 {
    delete playback_device_event_handler;
    playback_device_event_handler = nullptr;
    delete capture_device_event_handler;
    capture_device_event_handler = nullptr;
 }
 void WASAPI_EnumerateEndpoints(void)
 {
    // DeviceWatchers will fire an Added event for each existing device at
    //  startup, so we don't need to enumerate them separately before
    //  listening for updates.
    playback_device_event_handler = new SDL_WasapiDeviceEventHandler(SDL_FALSE);
    capture_device_event_handler = new SDL_WasapiDeviceEventHandler(SDL_TRUE);
 }
 struct SDL_WasapiActivationHandler : public RuntimeClass< RuntimeClassFlags< ClassicCom >, FtmBase, IActivateAudioInterfaceCompletionHandler >
 {
    SDL_WasapiActivationHandler() : device(nullptr) {}
    STDMETHOD(ActivateCompleted)(IActivateAudioInterfaceAsyncOperation *operation);
    SDL_AudioDevice *device;
 };
 HRESULT
 SDL_WasapiActivationHandler::ActivateCompleted(IActivateAudioInterfaceAsyncOperation *async)
 {
    HRESULT result = S_OK;
    IUnknown *iunknown = nullptr;
    const HRESULT ret = async->GetActivateResult(&result, &iunknown);
    if (SUCCEEDED(ret) && SUCCEEDED(result)) {
        iunknown->QueryInterface(IID_PPV_ARGS(&device->hidden->client));
        if (device->hidden->client) {
            // Just set a flag, since we're probably in a different thread. We'll pick it up and init everything on our own thread to prevent races.
            SDL_AtomicSet(&device->hidden->just_activated, 1);
        }
    }
    WASAPI_UnrefDevice(device);
    return S_OK;
 }
 void
 WASAPI_PlatformDeleteActivationHandler(void *handler)
 {
    ((SDL_WasapiActivationHandler *) handler)->Release();
 }
 int
 WASAPI_ActivateDevice(_THIS, const SDL_bool isrecovery)
 {
    LPCWSTR devid = _this->hidden->devid;
    Platform::String^ defdevid;
    if (devid == nullptr) {
        defdevid = _this->iscapture ? MediaDevice::GetDefaultAudioCaptureId(AudioDeviceRole::Default) : MediaDevice::GetDefaultAudioRenderId(AudioDeviceRole::Default);
        if (defdevid) {
            devid = defdevid->Data();
        }
    }
    SDL_AtomicSet(&_this->hidden->just_activated, 0);
    ComPtr<SDL_WasapiActivationHandler> handler = Make<SDL_WasapiActivationHandler>();
    if (handler == nullptr) {
        return SDL_SetError("Failed to allocate WASAPI activation handler");
    }
    handler.Get()->AddRef();  // we hold a reference after ComPtr destructs on return, causing a Release, and Release ourselves in WASAPI_PlatformDeleteActivationHandler(), etc.
    handler.Get()->device = _this;
    _this->hidden->activation_handler = handler.Get();
    WASAPI_RefDevice(_this);  /* completion handler will unref it. */
    IActivateAudioInterfaceAsyncOperation *async = nullptr;
    const HRESULT ret = ActivateAudioInterfaceAsync(devid, __uuidof(IAudioClient), nullptr, handler.Get(), &async);
    if (async != nullptr) {
        async->Release();
    }
    if (FAILED(ret)) {
        handler.Get()->Release();
        WASAPI_UnrefDevice(_this);
        return WIN_SetErrorFromHRESULT("WASAPI can't activate requested audio endpoint", ret);
    }
    return 0;
 }
 void
 WASAPI_BeginLoopIteration(_THIS)
 {
    if (SDL_AtomicCAS(&_this->hidden->just_activated, 1, 0)) {
        if (WASAPI_PrepDevice(_this, SDL_TRUE) == -1) {
            SDL_OpenedAudioDeviceDisconnected(_this);
        } 
    }
 }
 void
 WASAPI_PlatformThreadInit(_THIS)
 {
    // !!! FIXME: set this thread to "Pro Audio" priority.
 }
 void
 WASAPI_PlatformThreadDeinit(_THIS)
 {
    // !!! FIXME: set this thread to "Pro Audio" priority.
 }
 #endif  // SDL_AUDIO_DRIVER_WASAPI && defined(__WINRT__)
 /* vi: set ts=4 sw=4 expandtab: */
--- a/src/audio/xaudio2/SDL_xaudio2.c
+++ b/src/audio/xaudio2/SDL_xaudio2.c
@ -1,505 +0,0 @@
 /*
  Simple DirectMedia Layer
  Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
 */
 /* WinRT NOTICE:
   A few changes to SDL's XAudio2 backend were warranted by API
   changes to Windows.  Many, but not all of these are documented by Microsoft
   at:
   http://blogs.msdn.com/b/chuckw/archive/2012/04/02/xaudio2-and-windows-8-consumer-preview.aspx
   1. Windows' thread synchronization function, CreateSemaphore, was removed
      from WinRT.  SDL's semaphore API was substituted instead.
   2. The method calls, IXAudio2::GetDeviceCount and IXAudio2::GetDeviceDetails
      were removed from the XAudio2 API.  Microsoft is telling developers to
      use APIs in Windows::Foundation instead.
      For SDL, the missing methods were reimplemented using the APIs Microsoft
      said to use.
   3. CoInitialize and CoUninitialize are not available in WinRT.
      These calls were removed, as COM will have been initialized earlier,
      at least by the call to the WinRT app's main function
      (aka 'int main(Platform::Array<Platform::String^>^)).  (DLudwig:
      This was my understanding of how WinRT: the 'main' function uses
      a tag of [MTAThread], which should initialize COM.  My understanding
      of COM is somewhat limited, and I may be incorrect here.)
   4. IXAudio2::CreateMasteringVoice changed its integer-based 'DeviceIndex'
      argument to a string-based one, 'szDeviceId'.  In WinRT, the
      string-based argument will be used.
 */
 #include "../../SDL_internal.h"
 #if SDL_AUDIO_DRIVER_XAUDIO2
 #include "../../core/windows/SDL_windows.h"
 #include "SDL_audio.h"
 #include "../SDL_audio_c.h"
 #include "../SDL_sysaudio.h"
 #include "SDL_assert.h"
 #ifdef __GNUC__
 /* The configure script already did any necessary checking */
 #  define SDL_XAUDIO2_HAS_SDK 1
 #elif defined(__WINRT__)
 /* WinRT always has access to the XAudio 2 SDK (albeit with a header file
   that doesn't compile as C code).
 */
 #  define SDL_XAUDIO2_HAS_SDK
 #include "SDL_xaudio2.h"    /* ... compiles as C code, in contrast to XAudio2 headers
                               in the Windows SDK, v.10.0.10240.0 (Win 10's initial SDK)
                             */
 #else
 /* XAudio2 exists in the last DirectX SDK as well as the latest Windows SDK.
   To enable XAudio2 support, you will need to add the location of your DirectX SDK headers to
   the SDL projects additional include directories and then set SDL_XAUDIO2_HAS_SDK=1 as a
   preprocessor define
 */
 #if 0 /* See comment above */
 #include <dxsdkver.h>
 #if (!defined(_DXSDK_BUILD_MAJOR) || (_DXSDK_BUILD_MAJOR < 1284))
 #  pragma message("Your DirectX SDK is too old. Disabling XAudio2 support.")
 #else
 #  define SDL_XAUDIO2_HAS_SDK 1
 #endif
 #endif /* 0 */
 #endif /* __GNUC__ */
 #ifdef SDL_XAUDIO2_HAS_SDK
 /* Check to see if we're compiling for XAudio 2.8, or higher. */
 #ifdef WINVER
 #if WINVER >= 0x0602  /* Windows 8 SDK or higher? */
 #define SDL_XAUDIO2_WIN8 1
 #endif
 #endif
 #if !defined(SDL_XAUDIO2_H_)
 #define INITGUID 1
 #include <xaudio2.h>
 #endif
 /* Hidden "this" pointer for the audio functions */
 #define _THIS   SDL_AudioDevice *this
 #ifdef __WINRT__
 #include "SDL_xaudio2_winrthelpers.h"
 #endif
 /* Fixes bug 1210 where some versions of gcc need named parameters */
 #ifdef __GNUC__
 #ifdef THIS
 #undef THIS
 #endif
 #define THIS    INTERFACE *p
 #ifdef THIS_
 #undef THIS_
 #endif
 #define THIS_   INTERFACE *p,
 #endif
 struct SDL_PrivateAudioData
 {
    IXAudio2 *ixa2;
    IXAudio2SourceVoice *source;
    IXAudio2MasteringVoice *mastering;
    SDL_sem * semaphore;
    Uint8 *mixbuf;
    int mixlen;
    Uint8 *nextbuf;
 };
 static void
 XAUDIO2_DetectDevices(void)
 {
    IXAudio2 *ixa2 = NULL;
    UINT32 devcount = 0;
    UINT32 i = 0;
    if (XAudio2Create(&ixa2, 0, XAUDIO2_DEFAULT_PROCESSOR) != S_OK) {
        SDL_SetError("XAudio2: XAudio2Create() failed at detection.");
        return;
    } else if (IXAudio2_GetDeviceCount(ixa2, &devcount) != S_OK) {
        SDL_SetError("XAudio2: IXAudio2::GetDeviceCount() failed.");
        IXAudio2_Release(ixa2);
        return;
    }
    for (i = 0; i < devcount; i++) {
        XAUDIO2_DEVICE_DETAILS details;
        if (IXAudio2_GetDeviceDetails(ixa2, i, &details) == S_OK) {
            char *str = WIN_StringToUTF8(details.DisplayName);
            if (str != NULL) {
                SDL_AddAudioDevice(SDL_FALSE, str, (void *) ((size_t) i+1));
                SDL_free(str);  /* SDL_AddAudioDevice made a copy of the string. */
            }
        }
    }
    IXAudio2_Release(ixa2);
 }
 static void STDMETHODCALLTYPE
 VoiceCBOnBufferEnd(THIS_ void *data)
 {
    /* Just signal the SDL audio thread and get out of XAudio2's way. */
    SDL_AudioDevice *this = (SDL_AudioDevice *) data;
    SDL_SemPost(this->hidden->semaphore);
 }
 static void STDMETHODCALLTYPE
 VoiceCBOnVoiceError(THIS_ void *data, HRESULT Error)
 {
    SDL_AudioDevice *this = (SDL_AudioDevice *) data;
    SDL_OpenedAudioDeviceDisconnected(this);
 }
 /* no-op callbacks... */
 static void STDMETHODCALLTYPE VoiceCBOnStreamEnd(THIS) {}
 static void STDMETHODCALLTYPE VoiceCBOnVoiceProcessPassStart(THIS_ UINT32 b) {}
 static void STDMETHODCALLTYPE VoiceCBOnVoiceProcessPassEnd(THIS) {}
 static void STDMETHODCALLTYPE VoiceCBOnBufferStart(THIS_ void *data) {}
 static void STDMETHODCALLTYPE VoiceCBOnLoopEnd(THIS_ void *data) {}
 static Uint8 *
 XAUDIO2_GetDeviceBuf(_THIS)
 {
    return this->hidden->nextbuf;
 }
 static void
 XAUDIO2_PlayDevice(_THIS)
 {
    XAUDIO2_BUFFER buffer;
    Uint8 *mixbuf = this->hidden->mixbuf;
    Uint8 *nextbuf = this->hidden->nextbuf;
    const int mixlen = this->hidden->mixlen;
    IXAudio2SourceVoice *source = this->hidden->source;
    HRESULT result = S_OK;
    if (!SDL_AtomicGet(&this->enabled)) { /* shutting down? */
        return;
    }
    /* Submit the next filled buffer */
    SDL_zero(buffer);
    buffer.AudioBytes = mixlen;
    buffer.pAudioData = nextbuf;
    buffer.pContext = this;
    if (nextbuf == mixbuf) {
        nextbuf += mixlen;
    } else {
        nextbuf = mixbuf;
    }
    this->hidden->nextbuf = nextbuf;
    result = IXAudio2SourceVoice_SubmitSourceBuffer(source, &buffer, NULL);
    if (result == XAUDIO2_E_DEVICE_INVALIDATED) {
        /* !!! FIXME: possibly disconnected or temporary lost. Recover? */
    }
    if (result != S_OK) {  /* uhoh, panic! */
        IXAudio2SourceVoice_FlushSourceBuffers(source);
        SDL_OpenedAudioDeviceDisconnected(this);
    }
 }
 static void
 XAUDIO2_WaitDevice(_THIS)
 {
    if (SDL_AtomicGet(&this->enabled)) {
        SDL_SemWait(this->hidden->semaphore);
    }
 }
 static void
 XAUDIO2_PrepareToClose(_THIS)
 {
    IXAudio2SourceVoice *source = this->hidden->source;
    if (source) {
        IXAudio2SourceVoice_Discontinuity(source);
    }
 }
 static void
 XAUDIO2_CloseDevice(_THIS)
 {
    IXAudio2 *ixa2 = this->hidden->ixa2;
    IXAudio2SourceVoice *source = this->hidden->source;
    IXAudio2MasteringVoice *mastering = this->hidden->mastering;
    if (source != NULL) {
        IXAudio2SourceVoice_Stop(source, 0, XAUDIO2_COMMIT_NOW);
        IXAudio2SourceVoice_FlushSourceBuffers(source);
        IXAudio2SourceVoice_DestroyVoice(source);
    }
    if (ixa2 != NULL) {
        IXAudio2_StopEngine(ixa2);
    }
    if (mastering != NULL) {
        IXAudio2MasteringVoice_DestroyVoice(mastering);
    }
    if (ixa2 != NULL) {
        IXAudio2_Release(ixa2);
    }
    if (this->hidden->semaphore != NULL) {
        SDL_DestroySemaphore(this->hidden->semaphore);
    }
    SDL_free(this->hidden->mixbuf);
    SDL_free(this->hidden);
 }
 static int
 XAUDIO2_OpenDevice(_THIS, void *handle, const char *devname, int iscapture)
 {
    HRESULT result = S_OK;
    WAVEFORMATEX waveformat;
    int valid_format = 0;
    SDL_AudioFormat test_format = SDL_FirstAudioFormat(this->spec.format);
    IXAudio2 *ixa2 = NULL;
    IXAudio2SourceVoice *source = NULL;
 #if defined(SDL_XAUDIO2_WIN8)
    LPCWSTR devId = NULL;
 #else
    UINT32 devId = 0;  /* 0 == system default device. */
 #endif
    static IXAudio2VoiceCallbackVtbl callbacks_vtable = {
        VoiceCBOnVoiceProcessPassStart,
        VoiceCBOnVoiceProcessPassEnd,
        VoiceCBOnStreamEnd,
        VoiceCBOnBufferStart,
        VoiceCBOnBufferEnd,
        VoiceCBOnLoopEnd,
        VoiceCBOnVoiceError
    };
    static IXAudio2VoiceCallback callbacks = { &callbacks_vtable };
 #if defined(SDL_XAUDIO2_WIN8)
    /* !!! FIXME: hook up hotplugging. */
 #else
    if (handle != NULL) {  /* specific device requested? */
        /* -1 because we increment the original value to avoid NULL. */
        const size_t val = ((size_t) handle) - 1;
        devId = (UINT32) val;
    }
 #endif
    if (XAudio2Create(&ixa2, 0, XAUDIO2_DEFAULT_PROCESSOR) != S_OK) {
        return SDL_SetError("XAudio2: XAudio2Create() failed at open.");
    }
    /*
    XAUDIO2_DEBUG_CONFIGURATION debugConfig;
    debugConfig.TraceMask = XAUDIO2_LOG_ERRORS; //XAUDIO2_LOG_WARNINGS | XAUDIO2_LOG_DETAIL | XAUDIO2_LOG_FUNC_CALLS | XAUDIO2_LOG_TIMING | XAUDIO2_LOG_LOCKS | XAUDIO2_LOG_MEMORY | XAUDIO2_LOG_STREAMING;
    debugConfig.BreakMask = XAUDIO2_LOG_ERRORS; //XAUDIO2_LOG_WARNINGS;
    debugConfig.LogThreadID = TRUE;
    debugConfig.LogFileline = TRUE;
    debugConfig.LogFunctionName = TRUE;
    debugConfig.LogTiming = TRUE;
    ixa2->SetDebugConfiguration(&debugConfig);
    */
    /* Initialize all variables that we clean on shutdown */
    this->hidden = (struct SDL_PrivateAudioData *)
        SDL_malloc((sizeof *this->hidden));
    if (this->hidden == NULL) {
        IXAudio2_Release(ixa2);
        return SDL_OutOfMemory();
    }
    SDL_zerop(this->hidden);
    this->hidden->ixa2 = ixa2;
    this->hidden->semaphore = SDL_CreateSemaphore(1);
    if (this->hidden->semaphore == NULL) {
        return SDL_SetError("XAudio2: CreateSemaphore() failed!");
    }
    while ((!valid_format) && (test_format)) {
        switch (test_format) {
        case AUDIO_U8:
        case AUDIO_S16:
        case AUDIO_S32:
        case AUDIO_F32:
            this->spec.format = test_format;
            valid_format = 1;
            break;
        }
        test_format = SDL_NextAudioFormat();
    }
    if (!valid_format) {
        return SDL_SetError("XAudio2: Unsupported audio format");
    }
    /* Update the fragment size as size in bytes */
    SDL_CalculateAudioSpec(&this->spec);
    /* We feed a Source, it feeds the Mastering, which feeds the device. */
    this->hidden->mixlen = this->spec.size;
    this->hidden->mixbuf = (Uint8 *) SDL_malloc(2 * this->hidden->mixlen);
    if (this->hidden->mixbuf == NULL) {
        return SDL_OutOfMemory();
    }
    this->hidden->nextbuf = this->hidden->mixbuf;
    SDL_memset(this->hidden->mixbuf, this->spec.silence, 2 * this->hidden->mixlen);
    /* We use XAUDIO2_DEFAULT_CHANNELS instead of this->spec.channels. On
       Xbox360, this means 5.1 output, but on Windows, it means "figure out
       what the system has." It might be preferable to let XAudio2 blast
       stereo output to appropriate surround sound configurations
       instead of clamping to 2 channels, even though we'll configure the
       Source Voice for whatever number of channels you supply. */
 #if SDL_XAUDIO2_WIN8
    result = IXAudio2_CreateMasteringVoice(ixa2, &this->hidden->mastering,
                                           XAUDIO2_DEFAULT_CHANNELS,
                                           this->spec.freq, 0, devId, NULL, AudioCategory_GameEffects);
 #else
    result = IXAudio2_CreateMasteringVoice(ixa2, &this->hidden->mastering,
                                           XAUDIO2_DEFAULT_CHANNELS,
                                           this->spec.freq, 0, devId, NULL);
 #endif
    if (result != S_OK) {
        return SDL_SetError("XAudio2: Couldn't create mastering voice");
    }
    SDL_zero(waveformat);
    if (SDL_AUDIO_ISFLOAT(this->spec.format)) {
        waveformat.wFormatTag = WAVE_FORMAT_IEEE_FLOAT;
    } else {
        waveformat.wFormatTag = WAVE_FORMAT_PCM;
    }
    waveformat.wBitsPerSample = SDL_AUDIO_BITSIZE(this->spec.format);
    waveformat.nChannels = this->spec.channels;
    waveformat.nSamplesPerSec = this->spec.freq;
    waveformat.nBlockAlign =
        waveformat.nChannels * (waveformat.wBitsPerSample / 8);
    waveformat.nAvgBytesPerSec =
        waveformat.nSamplesPerSec * waveformat.nBlockAlign;
    waveformat.cbSize = sizeof(waveformat);
 #ifdef __WINRT__
    // DLudwig: for now, make XAudio2 do sample rate conversion, just to
    // get the loopwave test to work.
    //
    // TODO, WinRT: consider removing WinRT-specific source-voice creation code from SDL_xaudio2.c
    result = IXAudio2_CreateSourceVoice(ixa2, &source, &waveformat,
                                        0,
                                        1.0f, &callbacks, NULL, NULL);
 #else
    result = IXAudio2_CreateSourceVoice(ixa2, &source, &waveformat,
                                        XAUDIO2_VOICE_NOSRC |
                                        XAUDIO2_VOICE_NOPITCH,
                                        1.0f, &callbacks, NULL, NULL);
 #endif
    if (result != S_OK) {
        return SDL_SetError("XAudio2: Couldn't create source voice");
    }
    this->hidden->source = source;
    /* Start everything playing! */
    result = IXAudio2_StartEngine(ixa2);
    if (result != S_OK) {
        return SDL_SetError("XAudio2: Couldn't start engine");
    }
    result = IXAudio2SourceVoice_Start(source, 0, XAUDIO2_COMMIT_NOW);
    if (result != S_OK) {
        return SDL_SetError("XAudio2: Couldn't start source voice");
    }
    return 0; /* good to go. */
 }
 static void
 XAUDIO2_Deinitialize(void)
 {
 #if defined(__WIN32__)
    WIN_CoUninitialize();
 #endif
 }
 #endif  /* SDL_XAUDIO2_HAS_SDK */
 static int
 XAUDIO2_Init(SDL_AudioDriverImpl * impl)
 {
 #ifndef SDL_XAUDIO2_HAS_SDK
    SDL_SetError("XAudio2: SDL was built without XAudio2 support (old DirectX SDK).");
    return 0;  /* no XAudio2 support, ever. Update your SDK! */
 #else
    /* XAudio2Create() is a macro that uses COM; we don't load the .dll */
    IXAudio2 *ixa2 = NULL;
    HRESULT hr = S_FALSE;
 #if defined(__WIN32__)
    // TODO, WinRT: Investigate using CoInitializeEx here
    if (FAILED(WIN_CoInitialize())) {
        SDL_SetError("XAudio2: CoInitialize() failed");
        return 0;
    }
 #endif
    hr = XAudio2Create( &ixa2, 0, XAUDIO2_DEFAULT_PROCESSOR );
    if ( hr != S_OK) {
 #if defined(__WIN32__)
        WIN_CoUninitialize();
 #endif
        SDL_SetError("XAudio2: XAudio2Create() failed at initialization: 0x%.8x", hr );
        return 0;  /* not available. */
    }
    IXAudio2_Release(ixa2);
    /* Set the function pointers */
    impl->DetectDevices = XAUDIO2_DetectDevices;
    impl->OpenDevice = XAUDIO2_OpenDevice;
    impl->PlayDevice = XAUDIO2_PlayDevice;
    impl->WaitDevice = XAUDIO2_WaitDevice;
    impl->PrepareToClose = XAUDIO2_PrepareToClose;
    impl->GetDeviceBuf = XAUDIO2_GetDeviceBuf;
    impl->CloseDevice = XAUDIO2_CloseDevice;
    impl->Deinitialize = XAUDIO2_Deinitialize;
    /* !!! FIXME: We can apparently use a C++ interface on Windows 8
     * !!! FIXME: (Windows::Devices::Enumeration::DeviceInformation) for device
     * !!! FIXME: detection, but it's not implemented here yet.
     * !!! FIXME:  see http://blogs.msdn.com/b/chuckw/archive/2012/04/02/xaudio2-and-windows-8-consumer-preview.aspx
     * !!! FIXME:  for now, force the default device.
     */
 #if defined(SDL_XAUDIO2_WIN8) || defined(__WINRT__)
    impl->OnlyHasDefaultOutputDevice = 1;
 #endif
    return 1;   /* this audio target is available. */
 #endif
 }
 AudioBootStrap XAUDIO2_bootstrap = {
    "xaudio2", "XAudio2", XAUDIO2_Init, 0
 };
 #endif  /* SDL_AUDIO_DRIVER_XAUDIO2 */
 /* vi: set ts=4 sw=4 expandtab: */
--- a/src/audio/xaudio2/SDL_xaudio2.h
+++ b/src/audio/xaudio2/SDL_xaudio2.h
@ -1,386 +0,0 @@
 /*
  Simple DirectMedia Layer
  Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
 */
 #ifndef SDL_XAUDIO2_H_
 #define SDL_XAUDIO2_H_
 #include <windows.h>
 #include <mmreg.h>
 #include <objbase.h>
 /* XAudio2 packs its structure members together as tightly as possible.
   This pragma is needed to ensure compatibility with XAudio2 on 64-bit
   platforms.
 */
 #pragma pack(push, 1)
 typedef interface IXAudio2 IXAudio2;
 typedef interface IXAudio2SourceVoice IXAudio2SourceVoice;
 typedef interface IXAudio2MasteringVoice IXAudio2MasteringVoice;
 typedef interface IXAudio2EngineCallback IXAudio2EngineCallback;
 typedef interface IXAudio2VoiceCallback IXAudio2VoiceCallback;
 typedef interface IXAudio2Voice IXAudio2Voice;
 typedef interface IXAudio2SubmixVoice IXAudio2SubmixVoice;
 typedef enum _AUDIO_STREAM_CATEGORY {
    AudioCategory_Other = 0,
    AudioCategory_ForegroundOnlyMedia,
    AudioCategory_BackgroundCapableMedia,
    AudioCategory_Communications,
    AudioCategory_Alerts,
    AudioCategory_SoundEffects,
    AudioCategory_GameEffects,
    AudioCategory_GameMedia,
    AudioCategory_GameChat,
    AudioCategory_Movie,
    AudioCategory_Media
 } AUDIO_STREAM_CATEGORY;
 typedef struct XAUDIO2_BUFFER {
    UINT32     Flags;
    UINT32     AudioBytes;
    const BYTE *pAudioData;
    UINT32     PlayBegin;
    UINT32     PlayLength;
    UINT32     LoopBegin;
    UINT32     LoopLength;
    UINT32     LoopCount;
    void       *pContext;
 } XAUDIO2_BUFFER;
 typedef struct XAUDIO2_BUFFER_WMA {
    const UINT32 *pDecodedPacketCumulativeBytes;
    UINT32       PacketCount;
 } XAUDIO2_BUFFER_WMA;
 typedef struct XAUDIO2_SEND_DESCRIPTOR {
    UINT32        Flags;
    IXAudio2Voice *pOutputVoice;
 } XAUDIO2_SEND_DESCRIPTOR;
 typedef struct XAUDIO2_VOICE_SENDS {
    UINT32                  SendCount;
    XAUDIO2_SEND_DESCRIPTOR *pSends;
 } XAUDIO2_VOICE_SENDS;
 typedef struct XAUDIO2_EFFECT_DESCRIPTOR {
    IUnknown *pEffect;
    BOOL     InitialState;
    UINT32   OutputChannels;
 } XAUDIO2_EFFECT_DESCRIPTOR;
 typedef struct XAUDIO2_EFFECT_CHAIN {
    UINT32                    EffectCount;
    XAUDIO2_EFFECT_DESCRIPTOR *pEffectDescriptors;
 } XAUDIO2_EFFECT_CHAIN;
 typedef struct XAUDIO2_PERFORMANCE_DATA {
    UINT64 AudioCyclesSinceLastQuery;
    UINT64 TotalCyclesSinceLastQuery;
    UINT32 MinimumCyclesPerQuantum;
    UINT32 MaximumCyclesPerQuantum;
    UINT32 MemoryUsageInBytes;
    UINT32 CurrentLatencyInSamples;
    UINT32 GlitchesSinceEngineStarted;
    UINT32 ActiveSourceVoiceCount;
    UINT32 TotalSourceVoiceCount;
    UINT32 ActiveSubmixVoiceCount;
    UINT32 ActiveResamplerCount;
    UINT32 ActiveMatrixMixCount;
    UINT32 ActiveXmaSourceVoices;
    UINT32 ActiveXmaStreams;
 } XAUDIO2_PERFORMANCE_DATA;
 typedef struct XAUDIO2_DEBUG_CONFIGURATION {
    UINT32 TraceMask;
    UINT32 BreakMask;
    BOOL   LogThreadID;
    BOOL   LogFileline;
    BOOL   LogFunctionName;
    BOOL   LogTiming;
 } XAUDIO2_DEBUG_CONFIGURATION;
 typedef struct XAUDIO2_VOICE_DETAILS {
    UINT32 CreationFlags;
    UINT32 ActiveFlags;
    UINT32 InputChannels;
    UINT32 InputSampleRate;
 } XAUDIO2_VOICE_DETAILS;
 typedef enum XAUDIO2_FILTER_TYPE {
    LowPassFilter = 0,
    BandPassFilter = 1,
    HighPassFilter = 2,
    NotchFilter = 3,
    LowPassOnePoleFilter = 4,
    HighPassOnePoleFilter = 5
 } XAUDIO2_FILTER_TYPE;
 typedef struct XAUDIO2_FILTER_PARAMETERS {
    XAUDIO2_FILTER_TYPE Type;
    float               Frequency;
    float               OneOverQ;
 } XAUDIO2_FILTER_PARAMETERS;
 typedef struct XAUDIO2_VOICE_STATE {
    void   *pCurrentBufferContext;
    UINT32 BuffersQueued;
    UINT64 SamplesPlayed;
 } XAUDIO2_VOICE_STATE;
 typedef UINT32 XAUDIO2_PROCESSOR;
 #define Processor1 0x00000001
 #define XAUDIO2_DEFAULT_PROCESSOR Processor1
 #define XAUDIO2_E_DEVICE_INVALIDATED 0x88960004
 #define XAUDIO2_COMMIT_NOW 0
 #define XAUDIO2_VOICE_NOSAMPLESPLAYED 0x0100
 #define XAUDIO2_DEFAULT_CHANNELS 0
 extern HRESULT __stdcall XAudio2Create(
    _Out_ IXAudio2          **ppXAudio2,
    _In_  UINT32            Flags,
    _In_  XAUDIO2_PROCESSOR XAudio2Processor
    );
 #undef INTERFACE
 #define INTERFACE IXAudio2
 typedef interface IXAudio2 {
    const struct IXAudio2Vtbl FAR* lpVtbl;
 } IXAudio2;
 typedef const struct IXAudio2Vtbl IXAudio2Vtbl;
 const struct IXAudio2Vtbl
 {
    /* IUnknown */
    STDMETHOD(QueryInterface)(THIS_ REFIID iid, LPVOID *ppv) PURE;
    STDMETHOD_(ULONG, AddRef)(THIS) PURE;
    STDMETHOD_(ULONG, Release)(THIS) PURE;
    /* IXAudio2 */
    STDMETHOD_(HRESULT, RegisterForCallbacks)(THIS, IXAudio2EngineCallback *pCallback) PURE;
    STDMETHOD_(VOID, UnregisterForCallbacks)(THIS, IXAudio2EngineCallback *pCallback) PURE;
    STDMETHOD_(HRESULT, CreateSourceVoice)(THIS, IXAudio2SourceVoice **ppSourceVoice,
                                           const WAVEFORMATEX *pSourceFormat,
                                           UINT32 Flags,
                                           float MaxFrequencyRatio,
                                           IXAudio2VoiceCallback *pCallback,
                                           const XAUDIO2_VOICE_SENDS *pSendList,
                                           const XAUDIO2_EFFECT_CHAIN *pEffectChain) PURE;
    STDMETHOD_(HRESULT, CreateSubmixVoice)(THIS, IXAudio2SubmixVoice **ppSubmixVoice,
                                           UINT32 InputChannels,
                                           UINT32 InputSampleRate,
                                           UINT32 Flags,
                                           UINT32 ProcessingStage,
                                           const XAUDIO2_VOICE_SENDS *pSendList,
                                           const XAUDIO2_EFFECT_CHAIN *pEffectChain) PURE;
    STDMETHOD_(HRESULT, CreateMasteringVoice)(THIS, IXAudio2MasteringVoice **ppMasteringVoice,
                                              UINT32 InputChannels,
                                              UINT32 InputSampleRate,
                                              UINT32 Flags,
                                              LPCWSTR szDeviceId,
                                              const XAUDIO2_EFFECT_CHAIN *pEffectChain,
                                              AUDIO_STREAM_CATEGORY StreamCategory) PURE;
    STDMETHOD_(HRESULT, StartEngine)(THIS) PURE;
    STDMETHOD_(VOID, StopEngine)(THIS) PURE;
    STDMETHOD_(HRESULT, CommitChanges)(THIS, UINT32 OperationSet) PURE;
    STDMETHOD_(HRESULT, GetPerformanceData)(THIS, XAUDIO2_PERFORMANCE_DATA *pPerfData) PURE;
    STDMETHOD_(HRESULT, SetDebugConfiguration)(THIS, XAUDIO2_DEBUG_CONFIGURATION *pDebugConfiguration,
                                               VOID *pReserved) PURE;
 };
 #define IXAudio2_Release(A) ((A)->lpVtbl->Release(A))
 #define IXAudio2_CreateSourceVoice(A,B,C,D,E,F,G,H) ((A)->lpVtbl->CreateSourceVoice(A,B,C,D,E,F,G,H))
 #define IXAudio2_CreateMasteringVoice(A,B,C,D,E,F,G,H) ((A)->lpVtbl->CreateMasteringVoice(A,B,C,D,E,F,G,H))
 #define IXAudio2_StartEngine(A) ((A)->lpVtbl->StartEngine(A))
 #define IXAudio2_StopEngine(A) ((A)->lpVtbl->StopEngine(A))
 #undef INTERFACE
 #define INTERFACE IXAudio2SourceVoice
 typedef interface IXAudio2SourceVoice {
    const struct IXAudio2SourceVoiceVtbl FAR* lpVtbl;
 } IXAudio2SourceVoice;
 typedef const struct IXAudio2SourceVoiceVtbl IXAudio2SourceVoiceVtbl;
 const struct IXAudio2SourceVoiceVtbl
 {
    /* MSDN says that IXAudio2Voice inherits from IXAudio2, but MSVC's debugger
     * says otherwise, and that IXAudio2Voice doesn't inherit from any other
     * interface!
     */
    /* IXAudio2Voice */
    STDMETHOD_(VOID, GetVoiceDetails)(THIS, XAUDIO2_VOICE_DETAILS *pVoiceDetails) PURE;
    STDMETHOD_(HRESULT, SetOutputVoices)(THIS, const XAUDIO2_VOICE_SENDS *pSendList) PURE;
    STDMETHOD_(HRESULT, SetEffectChain)(THIS, const XAUDIO2_EFFECT_CHAIN *pEffectChain) PURE;
    STDMETHOD_(HRESULT, EnableEffect)(THIS, UINT32 EffectIndex, UINT32 OperationSet) PURE;
    STDMETHOD_(HRESULT, DisableEffect)(THIS, UINT32 EffectIndex, UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetEffectState)(THIS, UINT32 EffectIndex, BOOL *pEnabled) PURE;
    STDMETHOD_(HRESULT, SetEffectParameters)(THIS, UINT32 EffectIndex,
                                             const void *pParameters,
                                             UINT32 ParametersByteSize,
                                             UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetEffectParameters)(THIS, UINT32 EffectIndex,
                                          void *pParameters,
                                          UINT32 ParametersByteSize) PURE;
    STDMETHOD_(HRESULT, SetFilterParameters)(THIS, const XAUDIO2_FILTER_PARAMETERS *pParameters,
                                             UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetFilterParameters)(THIS, XAUDIO2_FILTER_PARAMETERS *pParameters) PURE;
    STDMETHOD_(HRESULT, SetOutputFilterParameters)(THIS, IXAudio2Voice *pDestinationVoice,
                                                   XAUDIO2_FILTER_PARAMETERS *pParameters,
                                                   UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetOutputFilterParameters)(THIS, IXAudio2Voice *pDestinationVoice,
                                                XAUDIO2_FILTER_PARAMETERS *pParameters) PURE;
    STDMETHOD_(HRESULT, SetVolume)(THIS, float Volume,
                                   UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetVolume)(THIS, float *pVolume) PURE;
    STDMETHOD_(HRESULT, SetChannelVolumes)(THIS, UINT32 Channels,
                                           const float *pVolumes,
                                           UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetChannelVolumes)(THIS, UINT32 Channels,
                                        float *pVolumes) PURE;
    STDMETHOD_(HRESULT, SetOutputMatrix)(THIS, IXAudio2Voice *pDestinationVoice,
                                         UINT32 SourceChannels,
                                         UINT32 DestinationChannels,
                                         const float *pLevelMatrix,
                                         UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetOutputMatrix)(THIS, IXAudio2Voice *pDestinationVoice,
                                      UINT32 SourceChannels,
                                      UINT32 DestinationChannels,
                                      float *pLevelMatrix) PURE;
    STDMETHOD_(VOID, DestroyVoice)(THIS) PURE;
    /* IXAudio2SourceVoice */
    STDMETHOD_(HRESULT, Start)(THIS, UINT32 Flags,
                               UINT32 OperationSet) PURE;
    STDMETHOD_(HRESULT, Stop)(THIS, UINT32 Flags,
                              UINT32 OperationSet) PURE;
    STDMETHOD_(HRESULT, SubmitSourceBuffer)(THIS, const XAUDIO2_BUFFER *pBuffer,
                                            const XAUDIO2_BUFFER_WMA *pBufferWMA) PURE;
    STDMETHOD_(HRESULT, FlushSourceBuffers)(THIS) PURE;
    STDMETHOD_(HRESULT, Discontinuity)(THIS) PURE;
    STDMETHOD_(HRESULT, ExitLoop)(THIS, UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetState)(THIS, XAUDIO2_VOICE_STATE *pVoiceState,
                               UINT32 Flags) PURE;
    STDMETHOD_(HRESULT, SetFrequencyRatio)(THIS, float Ratio,
                                           UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetFrequencyRatio)(THIS, float *pRatio) PURE;
    STDMETHOD_(HRESULT, SetSourceSampleRate)(THIS, UINT32 NewSourceSampleRate) PURE;
 };
 #define IXAudio2SourceVoice_DestroyVoice(A) ((A)->lpVtbl->DestroyVoice(A))
 #define IXAudio2SourceVoice_Start(A,B,C) ((A)->lpVtbl->Start(A,B,C))
 #define IXAudio2SourceVoice_Stop(A,B,C) ((A)->lpVtbl->Stop(A,B,C))
 #define IXAudio2SourceVoice_SubmitSourceBuffer(A,B,C) ((A)->lpVtbl->SubmitSourceBuffer(A,B,C))
 #define IXAudio2SourceVoice_FlushSourceBuffers(A) ((A)->lpVtbl->FlushSourceBuffers(A))
 #define IXAudio2SourceVoice_Discontinuity(A) ((A)->lpVtbl->Discontinuity(A))
 #define IXAudio2SourceVoice_GetState(A,B,C) ((A)->lpVtbl->GetState(A,B,C))
 #undef INTERFACE
 #define INTERFACE IXAudio2MasteringVoice
 typedef interface IXAudio2MasteringVoice {
    const struct IXAudio2MasteringVoiceVtbl FAR* lpVtbl;
 } IXAudio2MasteringVoice;
 typedef const struct IXAudio2MasteringVoiceVtbl IXAudio2MasteringVoiceVtbl;
 const struct IXAudio2MasteringVoiceVtbl
 {
    /* MSDN says that IXAudio2Voice inherits from IXAudio2, but MSVC's debugger
     * says otherwise, and that IXAudio2Voice doesn't inherit from any other
     * interface!
     */
    /* IXAudio2Voice */
    STDMETHOD_(VOID, GetVoiceDetails)(THIS, XAUDIO2_VOICE_DETAILS *pVoiceDetails) PURE;
    STDMETHOD_(HRESULT, SetOutputVoices)(THIS, const XAUDIO2_VOICE_SENDS *pSendList) PURE;
    STDMETHOD_(HRESULT, SetEffectChain)(THIS, const XAUDIO2_EFFECT_CHAIN *pEffectChain) PURE;
    STDMETHOD_(HRESULT, EnableEffect)(THIS, UINT32 EffectIndex, UINT32 OperationSet) PURE;
    STDMETHOD_(HRESULT, DisableEffect)(THIS, UINT32 EffectIndex, UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetEffectState)(THIS, UINT32 EffectIndex, BOOL *pEnabled) PURE;
    STDMETHOD_(HRESULT, SetEffectParameters)(THIS, UINT32 EffectIndex,
                                             const void *pParameters,
                                             UINT32 ParametersByteSize,
                                             UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetEffectParameters)(THIS, UINT32 EffectIndex,
                                          void *pParameters,
                                          UINT32 ParametersByteSize) PURE;
    STDMETHOD_(HRESULT, SetFilterParameters)(THIS, const XAUDIO2_FILTER_PARAMETERS *pParameters,
                                             UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetFilterParameters)(THIS, XAUDIO2_FILTER_PARAMETERS *pParameters) PURE;
    STDMETHOD_(HRESULT, SetOutputFilterParameters)(THIS, IXAudio2Voice *pDestinationVoice,
                                                   XAUDIO2_FILTER_PARAMETERS *pParameters,
                                                   UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetOutputFilterParameters)(THIS, IXAudio2Voice *pDestinationVoice,
                                                XAUDIO2_FILTER_PARAMETERS *pParameters) PURE;
    STDMETHOD_(HRESULT, SetVolume)(THIS, float Volume,
                                   UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetVolume)(THIS, float *pVolume) PURE;
    STDMETHOD_(HRESULT, SetChannelVolumes)(THIS, UINT32 Channels,
                                           const float *pVolumes,
                                           UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetChannelVolumes)(THIS, UINT32 Channels,
                                        float *pVolumes) PURE;
    STDMETHOD_(HRESULT, SetOutputMatrix)(THIS, IXAudio2Voice *pDestinationVoice,
                                         UINT32 SourceChannels,
                                         UINT32 DestinationChannels,
                                         const float *pLevelMatrix,
                                         UINT32 OperationSet) PURE;
    STDMETHOD_(VOID, GetOutputMatrix)(THIS, IXAudio2Voice *pDestinationVoice,
                                      UINT32 SourceChannels,
                                      UINT32 DestinationChannels,
                                      float *pLevelMatrix) PURE;
    STDMETHOD_(VOID, DestroyVoice)(THIS) PURE;
    /* IXAudio2SourceVoice */
    STDMETHOD_(VOID, GetChannelMask)(THIS, DWORD *pChannelMask) PURE;
 };
 #define IXAudio2MasteringVoice_DestroyVoice(A) ((A)->lpVtbl->DestroyVoice(A))
 #undef INTERFACE
 #define INTERFACE IXAudio2VoiceCallback
 typedef interface IXAudio2VoiceCallback {
    const struct IXAudio2VoiceCallbackVtbl FAR* lpVtbl;
 } IXAudio2VoiceCallback;
 typedef const struct IXAudio2VoiceCallbackVtbl IXAudio2VoiceCallbackVtbl;
 const struct IXAudio2VoiceCallbackVtbl
 {
    /* MSDN says that IXAudio2VoiceCallback inherits from IXAudio2, but SDL's
     * own code says otherwise, and that IXAudio2VoiceCallback doesn't inherit
     * from any other interface!
     */
    /* IXAudio2VoiceCallback */
    STDMETHOD_(VOID, OnVoiceProcessingPassStart)(THIS, UINT32 BytesRequired) PURE;
    STDMETHOD_(VOID, OnVoiceProcessingPassEnd)(THIS) PURE;
    STDMETHOD_(VOID, OnStreamEnd)(THIS) PURE;
    STDMETHOD_(VOID, OnBufferStart)(THIS, void *pBufferContext) PURE;
    STDMETHOD_(VOID, OnBufferEnd)(THIS, void *pBufferContext) PURE;
    STDMETHOD_(VOID, OnLoopEnd)(THIS, void *pBufferContext) PURE;
    STDMETHOD_(VOID, OnVoiceError)(THIS, void *pBufferContext, HRESULT Error) PURE;
 };
 #pragma pack(pop)   /* Undo pragma push */
 #endif  /* SDL_XAUDIO2_H_ */
 /* vi: set ts=4 sw=4 expandtab: */
--- a/src/audio/xaudio2/SDL_xaudio2_winrthelpers.cpp
+++ b/src/audio/xaudio2/SDL_xaudio2_winrthelpers.cpp
@ -1,90 +0,0 @@
 /*
  Simple DirectMedia Layer
  Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
 */
 #include "../../SDL_internal.h"
 #include <xaudio2.h>
 #include "SDL_xaudio2_winrthelpers.h"
 #if WINAPI_FAMILY != WINAPI_FAMILY_PHONE_APP
 using Windows::Devices::Enumeration::DeviceClass;
 using Windows::Devices::Enumeration::DeviceInformation;
 using Windows::Devices::Enumeration::DeviceInformationCollection;
 #endif
 extern "C" HRESULT __cdecl IXAudio2_GetDeviceCount(IXAudio2 * ixa2, UINT32 * devcount)
 {
 #if WINAPI_FAMILY == WINAPI_FAMILY_PHONE_APP
    // There doesn't seem to be any audio device enumeration on Windows Phone.
    // In lieu of this, just treat things as if there is one and only one
    // audio device.
    *devcount = 1;
    return S_OK;
 #else
    // TODO, WinRT: make xaudio2 device enumeration only happen once, and in the background
    auto operation = DeviceInformation::FindAllAsync(DeviceClass::AudioRender);
    while (operation->Status != Windows::Foundation::AsyncStatus::Completed)
    {
    }
    DeviceInformationCollection^ devices = operation->GetResults();
    *devcount = devices->Size;
    return S_OK;
 #endif
 }
 extern "C" HRESULT IXAudio2_GetDeviceDetails(IXAudio2 * unused, UINT32 index, XAUDIO2_DEVICE_DETAILS * details)
 {
 #if WINAPI_FAMILY == WINAPI_FAMILY_PHONE_APP
    // Windows Phone doesn't seem to have the same device enumeration APIs that
    // Windows 8/RT has, or it doesn't have them at all.  In lieu of this,
    // just treat things as if there is one, and only one, default device.
    if (index != 0)
    {
        return XAUDIO2_E_INVALID_CALL;
    }
    if (details)
    {
        wcsncpy_s(details->DeviceID, ARRAYSIZE(details->DeviceID), L"default", _TRUNCATE);
        wcsncpy_s(details->DisplayName, ARRAYSIZE(details->DisplayName), L"default", _TRUNCATE);
    }
    return S_OK;
 #else
    auto operation = DeviceInformation::FindAllAsync(DeviceClass::AudioRender);
    while (operation->Status != Windows::Foundation::AsyncStatus::Completed)
    {
    }
    DeviceInformationCollection^ devices = operation->GetResults();
    if (index >= devices->Size)
    {
        return XAUDIO2_E_INVALID_CALL;
    }
    DeviceInformation^ d = devices->GetAt(index);
    if (details)
    {
        wcsncpy_s(details->DeviceID, ARRAYSIZE(details->DeviceID), d->Id->Data(), _TRUNCATE);
        wcsncpy_s(details->DisplayName, ARRAYSIZE(details->DisplayName), d->Name->Data(), _TRUNCATE);
    }
    return S_OK;
 #endif
 }
--- a/src/audio/xaudio2/SDL_xaudio2_winrthelpers.h
+++ b/src/audio/xaudio2/SDL_xaudio2_winrthelpers.h
@ -1,70 +0,0 @@
 /*
  Simple DirectMedia Layer
  Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
 */
 //
 // Re-implementation of methods removed from XAudio2 (in WinRT):
 //
 typedef struct XAUDIO2_DEVICE_DETAILS
 {
    WCHAR DeviceID[256];
    WCHAR DisplayName[256];
    /* Other fields exist in the pre-Windows 8 version of this struct, however
       they weren't used by SDL, so they weren't added.
    */
 } XAUDIO2_DEVICE_DETAILS;
 #ifdef __cplusplus
 extern "C" {
 #endif
 HRESULT IXAudio2_GetDeviceCount(IXAudio2 * unused, UINT32 * devcount);
 HRESULT IXAudio2_GetDeviceDetails(IXAudio2 * unused, UINT32 index, XAUDIO2_DEVICE_DETAILS * details);
 #ifdef __cplusplus
 }
 #endif
 //
 // C-style macros to call XAudio2's methods in C++:
 //
 #ifdef __cplusplus
 /*
 #define IXAudio2_CreateMasteringVoice(A, B, C, D, E, F, G) (A)->CreateMasteringVoice((B), (C), (D), (E), (F), (G))
 #define IXAudio2_CreateSourceVoice(A, B, C, D, E, F, G, H) (A)->CreateSourceVoice((B), (C), (D), (E), (F), (G), (H))
 #define IXAudio2_QueryInterface(A, B, C) (A)->QueryInterface((B), (C))
 #define IXAudio2_Release(A) (A)->Release()
 #define IXAudio2_StartEngine(A) (A)->StartEngine()
 #define IXAudio2_StopEngine(A) (A)->StopEngine()
 #define IXAudio2MasteringVoice_DestroyVoice(A) (A)->DestroyVoice()
 #define IXAudio2SourceVoice_DestroyVoice(A) (A)->DestroyVoice()
 #define IXAudio2SourceVoice_Discontinuity(A) (A)->Discontinuity()
 #define IXAudio2SourceVoice_FlushSourceBuffers(A) (A)->FlushSourceBuffers()
 #define IXAudio2SourceVoice_GetState(A, B) (A)->GetState((B))
 #define IXAudio2SourceVoice_Start(A, B, C) (A)->Start((B), (C))
 #define IXAudio2SourceVoice_Stop(A, B, C) (A)->Stop((B), (C))
 #define IXAudio2SourceVoice_SubmitSourceBuffer(A, B, C) (A)->SubmitSourceBuffer((B), (C))
 */
 #endif // ifdef __cplusplus