Frontend: Add audio backend to settings (switch-while-running)

src/core/spu.cpp

@@ -21,7 +21,6 @@ SPU::~SPU() = default;
 
 void SPU::Initialize(System* system, DMA* dma, InterruptController* interrupt_controller)
 {
-  m_audio_stream = system->GetHostInterface()->GetAudioStream();
   m_system = system;
   m_dma = dma;
   m_interrupt_controller = interrupt_controller;
@@ -109,7 +108,7 @@ bool SPU::DoState(StateWrapper& sw)
   sw.DoBytes(m_ram.data(), RAM_SIZE);
 
   if (sw.IsReading())
-    m_audio_stream->EmptyBuffers();
+    m_system->GetHostInterface()->GetAudioStream()->EmptyBuffers();
 
   return !sw.HasError();
 }
@@ -1006,7 +1005,7 @@ void SPU::GenerateSample()
   std::array<AudioStream::SampleType, 2> out_samples;
   out_samples[0] = Clamp16(ApplyVolume(left_sum, m_main_volume_left.GetVolume()));
   out_samples[1] = Clamp16(ApplyVolume(right_sum, m_main_volume_right.GetVolume()));
-  m_audio_stream->WriteSamples(out_samples.data(), 1);
+  m_system->GetHostInterface()->GetAudioStream()->WriteSamples(out_samples.data(), 1);
 
   // Write to capture buffers.
   WriteToCaptureBuffer(0, cd_audio_left);

src/core/spu.h

@@ -287,7 +287,6 @@ private:
   System* m_system = nullptr;
   DMA* m_dma = nullptr;
   InterruptController* m_interrupt_controller = nullptr;
-  AudioStream* m_audio_stream = nullptr;
 
   SPUCNT m_SPUCNT = {};
   SPUSTAT m_SPUSTAT = {};

src/duckstation/sdl_host_interface.cpp

@@ -201,10 +201,16 @@ void SDLHostInterface::SwitchGPURenderer()
   ClearImGuiFocus();
 }
 
-void SDLHostInterface::SwitchAudioRenderer()
+void SDLHostInterface::SwitchAudioBackend()
 {
   m_audio_stream.reset();
   CreateAudioStream();
+
+  if (m_system)
+  {
+    m_audio_stream->PauseOutput(false);
+    UpdateSpeedLimiterState();
+  }
 }
 
 void SDLHostInterface::UpdateFullscreen()
@@ -1162,14 +1168,26 @@ void SDLHostInterface::DrawSettingsWindow()
       }
 
       ImGui::NewLine();
-      if (DrawSettingsSectionHeader("Host Synchronization"))
+      if (DrawSettingsSectionHeader("Audio"))
       {
-        if (ImGui::Checkbox("Sync To Audio", &m_settings.audio_sync_enabled))
+        ImGui::Text("Backend:");
+        ImGui::SameLine(indent);
+
+        int backend = static_cast<int>(m_settings.audio_backend);
+        if (ImGui::Combo(
+              "##backend", &backend,
+              [](void*, int index, const char** out_text) {
+                *out_text = Settings::GetAudioBackendDisplayName(static_cast<AudioBackend>(index));
+                return true;
+              },
+              nullptr, static_cast<int>(AudioBackend::Count)))
         {
+          m_settings.audio_backend = static_cast<AudioBackend>(backend);
           settings_changed = true;
-          UpdateSpeedLimiterState();
+          SwitchAudioBackend();
         }
-        if (ImGui::Checkbox("Sync To Video", &m_settings.video_sync_enabled))
+
+        if (ImGui::Checkbox("Output Sync", &m_settings.audio_sync_enabled))
         {
           settings_changed = true;
           UpdateSpeedLimiterState();
@@ -1292,6 +1310,12 @@ void SDLHostInterface::DrawSettingsWindow()
           m_display->SetDisplayLinearFiltering(m_settings.display_linear_filtering);
           settings_changed = true;
         }
+
+        if (ImGui::Checkbox("VSync", &m_settings.video_sync_enabled))
+        {
+          settings_changed = true;
+          UpdateSpeedLimiterState();
+        }
       }
 
       ImGui::NewLine();

src/duckstation/sdl_host_interface.h

@@ -85,7 +85,7 @@ private:
 
   void QueueSwitchGPURenderer();
   void SwitchGPURenderer();
-  void SwitchAudioRenderer();
+  void SwitchAudioBackend();
   void UpdateFullscreen();
   void UpdateControllerMapping();