Make the sample rate queryable as a sysprop

Windows/DSoundStream.cpp

@@ -50,13 +50,16 @@ private:
 // TODO: Get rid of this
 static DSoundState *g_dsound;
 
-
 inline int RoundDown128(int x) {
 	return x & (~127);
 }
 
 int DSound_GetSampleRate() {
-	return g_dsound->GetSampleRate();
+	if (g_dsound) {
+		return g_dsound->GetSampleRate();
+	} else {
+		return 0;
+	}
 }
 
 bool DSoundState::createBuffer() {
@@ -246,7 +249,9 @@ int DSoundState::GetCurSample() {
 }
 
 void DSound_UpdateSound() {
-	g_dsound->UpdateSound();
+	if (g_dsound) {
+		g_dsound->UpdateSound();
+	}
 }
 
 bool DSound_StartSound(HWND window, StreamCallback _callback, int sampleRate) {

Windows/DSoundStream.h

@@ -5,7 +5,7 @@
 
 typedef int (*StreamCallback)(short *buffer, int numSamples, int bits, int rate, int channels);
 
-bool DSound_StartSound(HWND window, StreamCallback _callback, int sampleRate = 44100);
+bool DSound_StartSound(HWND window, StreamCallback _callback, int sampleRate);
 void DSound_UpdateSound();
 void DSound_StopSound();
 

Windows/main.cpp

@@ -30,6 +30,7 @@
 #include "Core/Config.h"
 #include "Core/SaveState.h"
 #include "Windows/EmuThread.h"
+#include "Windows/DSoundStream.h"
 #include "ext/disarm.h"
 
 #include "Common/LogManager.h"
@@ -256,7 +257,12 @@ std::string System_GetProperty(SystemProperty prop) {
 }
 
 int System_GetPropertyInt(SystemProperty prop) {
-  return -1;
+	switch (prop) {
+	case SYSPROP_AUDIO_SAMPLE_RATE:
+		return DSound_GetSampleRate();
+	default:
+		return -1;
+	}
 }
 
 void System_SendMessage(const char *command, const char *parameter) {