AudioCommon: if backend is unknown, use default backend

Source/Core/AudioCommon/AudioCommon.cpp

@@ -27,23 +27,37 @@ static bool s_sound_stream_running = false;
 constexpr int AUDIO_VOLUME_MIN = 0;
 constexpr int AUDIO_VOLUME_MAX = 100;
 
-void InitSoundStream()
+static std::unique_ptr<SoundStream> CreateSoundStreamForBackend(std::string_view backend)
 {
-  std::string backend = SConfig::GetInstance().sBackend;
   if (backend == BACKEND_CUBEB)
-    g_sound_stream = std::make_unique<CubebStream>();
+    return std::make_unique<CubebStream>();
   else if (backend == BACKEND_OPENAL && OpenALStream::isValid())
-    g_sound_stream = std::make_unique<OpenALStream>();
+    return std::make_unique<OpenALStream>();
   else if (backend == BACKEND_NULLSOUND)
-    g_sound_stream = std::make_unique<NullSound>();
+    return std::make_unique<NullSound>();
   else if (backend == BACKEND_ALSA && AlsaSound::isValid())
-    g_sound_stream = std::make_unique<AlsaSound>();
+    return std::make_unique<AlsaSound>();
   else if (backend == BACKEND_PULSEAUDIO && PulseAudio::isValid())
-    g_sound_stream = std::make_unique<PulseAudio>();
+    return std::make_unique<PulseAudio>();
   else if (backend == BACKEND_OPENSLES && OpenSLESStream::isValid())
-    g_sound_stream = std::make_unique<OpenSLESStream>();
+    return std::make_unique<OpenSLESStream>();
   else if (backend == BACKEND_WASAPI && WASAPIStream::isValid())
-    g_sound_stream = std::make_unique<WASAPIStream>();
+    return std::make_unique<WASAPIStream>();
+  return {};
+}
+
+void InitSoundStream()
+{
+  std::string backend = SConfig::GetInstance().sBackend;
+  g_sound_stream = CreateSoundStreamForBackend(backend);
+
+  if (!g_sound_stream)
+  {
+    WARN_LOG(AUDIO, "Unknown backend %s, using %s instead.", backend.c_str(),
+             GetDefaultSoundBackend().c_str());
+    backend = GetDefaultSoundBackend();
+    g_sound_stream = CreateSoundStreamForBackend(GetDefaultSoundBackend());
+  }
 
   if (!g_sound_stream || !g_sound_stream->Init())
   {