fix sound crackling

source/preferences.cpp

@@ -478,12 +478,13 @@ DefaultSettings ()
 	Settings.HDMATimingHack = 100;
 
 	// Sound defaults. On Wii this is 32Khz/16bit/Stereo
-	//Settings.SoundSync = true;
+	Settings.SoundSync = true;
 	Settings.SixteenBitSound = true;
 	Settings.Stereo = true;
 	Settings.ReverseStereo = true;
 	Settings.SoundPlaybackRate = 32040;
-	Settings.SoundInputRate = 32040;
+	Settings.SoundInputRate = 32000;
+	Settings.DynamicRateControl = true;
 
 	// Graphics
 	Settings.Transparency = true;

source/s9xsupport.cpp

@@ -85,11 +85,7 @@ void S9xInitSync()
 
 /*** Synchronisation ***/
 
-void S9xSyncSpeed ()
-{
-	while (!S9xSyncSound())
-		usleep(10);
-
+void S9xSyncSpeed () {
 	uint32 skipFrms = Settings.SkipFrames;
 
 	if (Settings.TurboMode)

source/snes9x/apu/SNES_SPC.cpp

@@ -131,7 +131,6 @@ void SNES_SPC::enable_rom( int enable )
 			int count = (time) - m.dsp_time;\
 			if ( !SPC_MORE_ACCURACY || count )\
 			{\
-				assert( count > 0 );\
 				m.dsp_time = (time);\
 				dsp.run( count );\
 			}\
@@ -402,7 +401,7 @@ void SNES_SPC::cpu_write_high( int data, int i, rel_time_t time )
 	}
 	else
 	{
-		assert( *(&(RAM [0]) + i + rom_addr) == (uint8_t) data );
+		//assert( *(&(RAM [0]) + i + rom_addr) == (uint8_t) data );
 		*(&(RAM [0]) + i + rom_addr) = cpu_pad_fill; // restore overwritten padding
 		cpu_write( data, i + rom_addr - 0x10000, time );
 	}
@@ -494,7 +493,7 @@ int SNES_SPC::cpu_read( int addr, rel_time_t time )
 			}
 			else // 1%
 			{
-				assert( reg + (r_t0out + 0xF0 - 0x10000) < 0x100 );
+				//assert( reg + (r_t0out + 0xF0 - 0x10000) < 0x100 );
 				result = cpu_read( reg + (r_t0out + 0xF0 - 0x10000), time );
 			}
 		}
@@ -543,7 +542,7 @@ void SNES_SPC::end_frame( time_t end_time )
 	// Greatest number of clocks early that emulation can stop early due to
 	// not being able to execute current instruction without going over
 	// allowed time.
-	assert( -cpu_lag_max <= m.spc_time && m.spc_time <= cpu_lag_max );
+	//assert( -cpu_lag_max <= m.spc_time && m.spc_time <= cpu_lag_max );
 	
 	// Catch timers up to CPU
 	for ( int i = 0; i < timer_count; i++ )

source/snes9x/apu/apu.cpp

@@ -237,6 +237,8 @@ namespace spc
 	   if necessary on game load. */
 	static uint32		ratio_numerator = APU_NUMERATOR_NTSC;
 	static uint32		ratio_denominator = APU_DENOMINATOR_NTSC;
+
+	static double		dynamic_rate_multiplier = 1.0;
 }
 
 namespace msu
@@ -273,7 +275,7 @@ static void DeStereo (uint8 *buffer, int sample_count)
 	int16	*buf = (int16 *) buffer;
 	int32	s1, s2;
 
-	for (int i = 0; i < sample_count >> 1; i++)
+	for (int i = 0; i < (sample_count >> 1); i++)
 	{
 		s1 = (int32) buf[2 * i];
 		s2 = (int32) buf[2 * i + 1];
@@ -328,7 +330,9 @@ bool8 S9xMixSamples (uint8 *buffer, int sample_count)
 	{
 		memset(dest, 0, sample_count << 1);
 		spc::resampler->clear();
-        msu::resampler->clear();
+
+		if(Settings.MSU1)
+			msu::resampler->clear();
 
 		return (FALSE);
 	}
@@ -387,6 +391,24 @@ int S9xGetSampleCount (void)
 	return (spc::resampler->avail() >> (Settings.Stereo ? 0 : 1));
 }
 
+#ifdef GEKKO
+void S9xIncreaseDynamicRateMultiplier ()
+{
+	if(spc::dynamic_rate_multiplier != 1.001) {
+		spc::dynamic_rate_multiplier = 1.001;
+		UpdatePlaybackRate();
+	}
+}
+
+void S9xResetDynamicRateMultiplier ()
+{
+	if(spc::dynamic_rate_multiplier != 1.0) {
+		spc::dynamic_rate_multiplier = 1.0;
+		UpdatePlaybackRate();
+	}
+}
+#endif
+
 void S9xFinalizeSamples (void)
 {
 	bool drop_current_msu1_samples = TRUE;
@@ -399,6 +421,7 @@ void S9xFinalizeSamples (void)
 		{
 			/* We weren't able to process the entire buffer. Potential overrun. */
 			spc::sound_in_sync = FALSE;
+			S9xIncreaseDynamicRateMultiplier();
 			
 			if (Settings.SoundSync && !Settings.TurboMode)
 				return;
@@ -428,8 +451,14 @@ void S9xFinalizeSamples (void)
 	else
 	if (spc::resampler->space_empty() >= spc::resampler->space_filled())
 		spc::sound_in_sync = TRUE;
-	else
+	else {
+		S9xIncreaseDynamicRateMultiplier ();
 		spc::sound_in_sync = FALSE;
+	}
+
+	if(spc::sound_in_sync) {
+		S9xResetDynamicRateMultiplier ();
+	}
 
 	spc_core->set_output((SNES_SPC::sample_t *) spc::landing_buffer, spc::buffer_size >> 1);
 }
@@ -472,10 +501,19 @@ void UpdatePlaybackRate (void)
 		Settings.SoundInputRate = APU_DEFAULT_INPUT_RATE;
 
 	double time_ratio = (double) Settings.SoundInputRate * spc::timing_hack_numerator / (Settings.SoundPlaybackRate * spc::timing_hack_denominator);
+
+	if (Settings.DynamicRateControl)
+	{
+		time_ratio *= spc::dynamic_rate_multiplier;
+	}
+
 	spc::resampler->time_ratio(time_ratio);
 
-	time_ratio = (44100.0 / Settings.SoundPlaybackRate) * (Settings.SoundInputRate / 32040.0);
-	msu::resampler->time_ratio(time_ratio);
+	if (Settings.MSU1)
+	{
+		time_ratio = (44100.0 / Settings.SoundPlaybackRate) * (Settings.SoundInputRate / 32040.0);
+		msu::resampler->time_ratio(time_ratio);
+	}
 }
 
 bool8 S9xInitSound (int buffer_ms, int lag_ms)
@@ -712,7 +750,9 @@ void S9xResetAPU (void)
 	spc_core->set_output((SNES_SPC::sample_t *) spc::landing_buffer, spc::buffer_size >> 1);
 
 	spc::resampler->clear();
-	msu::resampler->clear();
+
+	if (Settings.MSU1)
+		msu::resampler->clear();
 }
 
 void S9xSoftResetAPU (void)
@@ -723,7 +763,9 @@ void S9xSoftResetAPU (void)
 	spc_core->set_output((SNES_SPC::sample_t *) spc::landing_buffer, spc::buffer_size >> 1);
 
 	spc::resampler->clear();
-	msu::resampler->clear();
+
+	if (Settings.MSU1)
+		msu::resampler->clear();
 }
 
 static void from_apu_to_state (uint8 **buf, void *var, size_t size)

source/snes9x/snes9x.h

@@ -423,6 +423,7 @@ struct SSettings
 	bool8	Stereo;
 	bool8	ReverseStereo;
 	bool8	Mute;
+	bool8	DynamicRateControl;
 
 	bool8	SupportHiRes;
 	bool8	Transparency;

source/video.cpp

@@ -638,7 +638,7 @@ ResetVideo_Emu ()
 		else
 			ResetFbWidth(512, rmode);
 		
-		Settings.SoundInputRate = 31953;
+		Settings.SoundInputRate = 32000;
 		UpdatePlaybackRate();
 	}