audout: FlushAudioOutBuffers

Fixes Devil May Cry

src/audio_core/stream.cpp

@@ -51,6 +51,14 @@ void Stream::Stop() {
     UNIMPLEMENTED();
 }
 
+bool Stream::Flush() {
+    const bool had_buffers = !queued_buffers.empty();
+    while (!queued_buffers.empty()) {
+        queued_buffers.pop();
+    }
+    return had_buffers;
+}
+
 void Stream::SetVolume(float volume) {
     game_volume = volume;
 }

src/audio_core/stream.h

@@ -56,6 +56,9 @@ public:
     /// Queues a buffer into the audio stream, returns true on success
     bool QueueBuffer(BufferPtr&& buffer);
 
+    /// Flush audio buffers
+    bool Flush();
+
     /// Returns true if the audio stream contains a buffer with the specified tag
     [[nodiscard]] bool ContainsBuffer(Buffer::Tag tag) const;
 

src/core/hle/service/audio/audout_u.cpp

@@ -58,7 +58,7 @@ public:
             {8, &IAudioOut::GetReleasedAudioOutBufferImpl, "GetReleasedAudioOutBufferAuto"},
             {9, &IAudioOut::GetAudioOutBufferCount, "GetAudioOutBufferCount"},
             {10, nullptr, "GetAudioOutPlayedSampleCount"},
-            {11, nullptr, "FlushAudioOutBuffers"},
+            {11, &IAudioOut::FlushAudioOutBuffers, "FlushAudioOutBuffers"},
             {12, &IAudioOut::SetAudioOutVolume, "SetAudioOutVolume"},
             {13, &IAudioOut::GetAudioOutVolume, "GetAudioOutVolume"},
         };
@@ -185,6 +185,14 @@ private:
         rb.Push(static_cast<u32>(stream->GetQueueSize()));
     }
 
+    void FlushAudioOutBuffers(Kernel::HLERequestContext& ctx) {
+        LOG_DEBUG(Service_Audio, "called");
+
+        IPC::ResponseBuilder rb{ctx, 3};
+        rb.Push(RESULT_SUCCESS);
+        rb.Push(stream->Flush());
+    }
+
     void SetAudioOutVolume(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
         const float volume = rp.Pop<float>();