audio_core: Add interfaces for Sink and SinkStream.

src/audio_core/sink.h

@@ -0,0 +1,29 @@
+// Copyright 2018 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+
+#include "audio_core/sink_stream.h"
+#include "common/common_types.h"
+
+namespace AudioCore {
+
+constexpr char auto_device_name[] = "auto";
+
+/**
+ * This class is an interface for an audio sink. An audio sink accepts samples in stereo signed
+ * PCM16 format to be output. Sinks *do not* handle resampling and expect the correct sample rate.
+ * They are dumb outputs.
+ */
+class Sink {
+public:
+    virtual ~Sink() = default;
+    virtual SinkStream& AcquireSinkStream(u32 sample_rate, u32 num_channels) = 0;
+};
+
+using SinkPtr = std::unique_ptr<Sink>;
+
+} // namespace AudioCore