[APU] Changed default value of apu_max_queued_frames to 8.

Added ability to set it even lower to 4. However this might impact CPU usage.

src/xenia/apu/audio_system.cc

@@ -35,9 +35,10 @@
 // and let the normal AudioSystem handling take it, to prevent duplicate
 // implementations. They can be found in xboxkrnl_audio_xma.cc
 
-DEFINE_uint32(apu_max_queued_frames, 64,
+DEFINE_uint32(apu_max_queued_frames, 8,
               "Allows changing max buffered audio frames to reduce audio "
-              "delay. Minimum is 16.",
+              "delay. Lowering this value might cause performance issues. "
+              "Value range: [4-64]",
               "APU");
 
 namespace xe {
@@ -48,7 +49,9 @@ AudioSystem::AudioSystem(cpu::Processor* processor)
       processor_(processor),
       worker_running_(false) {
   std::memset(clients_, 0, sizeof(clients_));
-  queued_frames_ = std::max(cvars::apu_max_queued_frames, (uint32_t)16);
+  queued_frames_ = std::min(
+      static_cast<uint32_t>(kMaximumQueuedFrames),
+      std::max(cvars::apu_max_queued_frames, static_cast<uint32_t>(4)));
 
   for (size_t i = 0; i < kMaximumClientCount; ++i) {
     client_semaphores_[i] = xe::threading::Semaphore::Create(0, queued_frames_);