audio_core: Implement OpenAL backend (#6450)

src/audio_core/input_details.h

@@ -0,0 +1,36 @@
+// Copyright 2023 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <string>
+#include <string_view>
+#include <vector>
+#include "common/common_types.h"
+
+namespace AudioCore {
+
+class Input;
+
+enum class InputType : u32 {
+    Auto = 0,
+    Null = 1,
+    Static = 2,
+    Cubeb = 3,
+    OpenAL = 4,
+
+    NumInputTypes,
+};
+
+/// Gets the name of a input type.
+std::string_view GetInputName(InputType input_type);
+
+/// Gets the list of devices for a particular input identified by the given ID.
+std::vector<std::string> GetDeviceListForInput(InputType input_type);
+
+/// Creates an audio input identified by the given device ID.
+std::unique_ptr<Input> CreateInputFromID(InputType input_type, std::string_view device_id);
+
+} // namespace AudioCore