src/output: add wasapi output and mixer plugin

src/mixer/MixerList.hxx

@@ -36,6 +36,7 @@ extern const MixerPlugin oss_mixer_plugin;
 extern const MixerPlugin osx_mixer_plugin;
 extern const MixerPlugin pulse_mixer_plugin;
 extern const MixerPlugin winmm_mixer_plugin;
+extern const MixerPlugin wasapi_mixer_plugin;
 extern const MixerPlugin sndio_mixer_plugin;
 
 #endif

src/mixer/plugins/WasapiMixerPlugin.cxx

@@ -0,0 +1,128 @@
+/*
+ * Copyright 2020 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "mixer/MixerInternal.hxx"
+#include "output/plugins/WasapiOutputPlugin.hxx"
+#include "win32/Com.hxx"
+#include "win32/HResult.hxx"
+
+#include <cmath>
+#include <endpointvolume.h>
+#include <optional>
+
+class WasapiMixer final : public Mixer {
+	WasapiOutput &output;
+	std::optional<COM> com;
+
+public:
+	WasapiMixer(WasapiOutput &_output, MixerListener &_listener)
+	: Mixer(wasapi_mixer_plugin, _listener), output(_output) {}
+
+	void Open() override { com.emplace(); }
+
+	void Close() noexcept override { com.reset(); }
+
+	int GetVolume() override {
+		HRESULT result;
+		float volume_level;
+
+		if (wasapi_is_exclusive(output)) {
+			ComPtr<IAudioEndpointVolume> endpoint_volume;
+			result = wasapi_output_get_device(output)->Activate(
+				__uuidof(IAudioEndpointVolume), CLSCTX_ALL, nullptr,
+				endpoint_volume.AddressCast());
+			if (FAILED(result)) {
+				throw FormatHResultError(
+					result, "Unable to get device endpoint volume");
+			}
+
+			result = endpoint_volume->GetMasterVolumeLevelScalar(
+				&volume_level);
+			if (FAILED(result)) {
+				throw FormatHResultError(
+					result, "Unable to get master volume level");
+			}
+		} else {
+			ComPtr<ISimpleAudioVolume> session_volume;
+			result = wasapi_output_get_client(output)->GetService(
+				__uuidof(ISimpleAudioVolume),
+				session_volume.AddressCast<void>());
+			if (FAILED(result)) {
+				throw FormatHResultError(
+					result, "Unable to get client session volume");
+			}
+
+			result = session_volume->GetMasterVolume(&volume_level);
+			if (FAILED(result)) {
+				throw FormatHResultError(result,
+							 "Unable to get master volume");
+			}
+		}
+
+		return std::lround(volume_level * 100.0f);
+	}
+
+	void SetVolume(unsigned volume) override {
+		HRESULT result;
+		const float volume_level = volume / 100.0f;
+
+		if (wasapi_is_exclusive(output)) {
+			ComPtr<IAudioEndpointVolume> endpoint_volume;
+			result = wasapi_output_get_device(output)->Activate(
+				__uuidof(IAudioEndpointVolume), CLSCTX_ALL, nullptr,
+				endpoint_volume.AddressCast());
+			if (FAILED(result)) {
+				throw FormatHResultError(
+					result, "Unable to get device endpoint volume");
+			}
+
+			result = endpoint_volume->SetMasterVolumeLevelScalar(volume_level,
+									     nullptr);
+			if (FAILED(result)) {
+				throw FormatHResultError(
+					result, "Unable to set master volume level");
+			}
+		} else {
+			ComPtr<ISimpleAudioVolume> session_volume;
+			result = wasapi_output_get_client(output)->GetService(
+				__uuidof(ISimpleAudioVolume),
+				session_volume.AddressCast<void>());
+			if (FAILED(result)) {
+				throw FormatHResultError(
+					result, "Unable to get client session volume");
+			}
+
+			result = session_volume->SetMasterVolume(volume_level, nullptr);
+			if (FAILED(result)) {
+				throw FormatHResultError(result,
+							 "Unable to set master volume");
+			}
+		}
+	}
+};
+
+static Mixer *wasapi_mixer_init(EventLoop &, AudioOutput &ao, MixerListener &listener,
+				const ConfigBlock &) {
+	return new WasapiMixer(wasapi_output_downcast(ao), listener);
+}
+
+const MixerPlugin wasapi_mixer_plugin = {
+	wasapi_mixer_init,
+	false,
+};

src/mixer/plugins/meson.build

@@ -31,7 +31,10 @@ if libsndio_dep.found()
 endif
 
 if is_windows
-  mixer_plugins_sources += 'WinmmMixerPlugin.cxx'
+  mixer_plugins_sources += [
+    'WinmmMixerPlugin.cxx',
+    'WasapiMixerPlugin.cxx',
+  ]
 endif
 
 if is_android