Minor audio sink tuning to better play sound when running emulation speeds > 100%. Added logic to prevent the audio sink from emtpying when emulation is paused. This provides a seemless transition when transitioning in/out of pause.

src/drivers/Qt/sdl-sound.cpp

@@ -47,6 +47,7 @@ static double noiseGate = 0.0;
 static double noiseGateRate = 0.010;
 static bool   noiseGateActive = true;
 static bool   muteSoundOutput = false;
+static bool   fillInit = 1;
 
 static int s_mute = 0;
 
@@ -69,6 +70,34 @@ fillaudio(void *udata,
 	int16 *tmps = (int16*)stream;
 	len >>= 1;
 
+	if ( s_BufferIn > s_BufferSize25 )
+	{
+		fillInit = 0;
+	}
+	// If emulation is paused:
+	// 1. preserve sound buffer as is
+	// 2. fade from last known sample to zero
+	// 3. activate noise gate to avoid popping when coming out of pause.
+	if ( EmulationPaused || fillInit )
+	{
+		while ( len )
+		{
+			if ( sample > 0 )
+			{
+				sample--;
+			}
+			else if ( sample < 0 )
+			{
+				sample++;
+			}
+			*tmps = sample;
+			tmps++;
+			len--;
+		}
+		noiseGate = 0.0;
+		noiseGateActive = 1;
+		return;
+	}
 	mute = EmulationPaused || muteSoundOutput;
 
 	if ( mute || noiseGateActive )
@@ -106,7 +135,7 @@ fillaudio(void *udata,
 				s_BufferRead = (s_BufferRead + 1) % s_BufferSize;
 				s_BufferIn--;
 
-				*tmps = sample;
+				*tmps = sample * noiseGate;
 			}
 			else
 			{
@@ -210,6 +239,7 @@ InitSound()
 	noiseGate = 0.0;
 	noiseGateRate = 1.0 / (double)spec.samples;
 	noiseGateActive = true;
+	fillInit = 1;
 
 	s_Buffer = (int *)FCEU_dmalloc(sizeof(int) * s_BufferSize);
 
@@ -294,7 +324,7 @@ WriteSound(int32 *buf,
 
 		if ( s_BufferIn >= s_BufferSize50 )
 		{
-			ovrFlowSkip += 100;
+			ovrFlowSkip += 1;
 		}
 	}
 	else
@@ -409,6 +439,8 @@ WriteSound(int32 *buf,
 						SDL_LockAudio();
 					}
 
+					//printf("%i >= %i \n", skipCounter, ovrFlowSkip );
+
 					if ( skipCounter >= ovrFlowSkip )
 					{
 						s_Buffer[s_BufferWrite] = *buf;