Fix choppy audio playback of sound effects on Windows

Increase default audio buffer size

See: #680
See: 25aeb1c5

src/sound/win32_s.cpp

@@ -70,7 +70,7 @@ const char *SoundDriver_Win32::Start(const StringList &parm)
 	wfex.nAvgBytesPerSec = wfex.nSamplesPerSec * wfex.nBlockAlign;
 
 	/* Limit buffer size to prevent overflows. */
-	_bufsize = GetDriverParamInt(parm, "samples", 1024);
+	_bufsize = GetDriverParamInt(parm, "samples", 2048);
 	_bufsize = std::min<int>(_bufsize, UINT16_MAX);
 
 	try {

src/sound/xaudio2_s.cpp

@@ -205,7 +205,7 @@ const char *SoundDriver_XAudio2::Start(const StringList &parm)
 	wfex.nAvgBytesPerSec = wfex.nSamplesPerSec * wfex.nBlockAlign;
 
 	// Limit buffer size to prevent overflows
-	int bufsize = GetDriverParamInt(parm, "samples", 1024);
+	int bufsize = GetDriverParamInt(parm, "samples", 2048);
 	bufsize = std::min<int>(bufsize, UINT16_MAX);
 
 	_voice_context = new StreamingVoiceContext(bufsize * 4);