audio_core: Misc. improvements to stream/buffer/audio_out.

src/audio_core/audio_out.h

@@ -13,15 +13,13 @@
 
 namespace AudioCore {
 
-using StreamPtr = std::shared_ptr<Stream>;
-
 /**
  * Represents an audio playback interface, used to open and play audio streams
  */
 class AudioOut {
 public:
     /// Opens a new audio stream
-    StreamPtr OpenStream(int sample_rate, int num_channels,
+    StreamPtr OpenStream(u32 sample_rate, u32 num_channels,
                          Stream::ReleaseCallback&& release_callback);
 
     /// Returns a vector of recently released buffers specified by tag for the specified stream
@@ -37,7 +35,7 @@ public:
     bool QueueBuffer(StreamPtr stream, Buffer::Tag tag, std::vector<u8>&& data);
 
 private:
-    /// Active audio streams on the interface
+    SinkPtr sink;
     std::vector<StreamPtr> streams;
 };