Optimize the resampler a little. Update native with new ability to not force 44khz so we actually get any use.

This causes Nexus 4 and Nexus 9 to end up on the fast path, greatly decreasing audio latency!

This also removes the "atomic audio" setting as the new audio code is lock-free always.

Core/Config.cpp

@@ -334,8 +334,6 @@ static bool DefaultForceFlushToZero() {
 static ConfigSetting cpuSettings[] = {
 	ReportedConfigSetting("Jit", &g_Config.bJit, &DefaultJit, true, true),
 	ReportedConfigSetting("SeparateCPUThread", &g_Config.bSeparateCPUThread, false, true, true),
-	ConfigSetting("AtomicAudioLocks", &g_Config.bAtomicAudioLocks, false, true, true),
-
 	ReportedConfigSetting("SeparateIOThread", &g_Config.bSeparateIOThread, true, true, true),
 	ReportedConfigSetting("IOTimingMethod", &g_Config.iIOTimingMethod, IOTIMING_FAST, true, true),
 	ConfigSetting("FastMemoryAccess", &g_Config.bFastMemory, true, true, true),

Core/Config.h

@@ -118,7 +118,6 @@ public:
 	bool bSeparateCPUThread;
 	int iIOTimingMethod;
 	bool bSeparateIOThread;
-	bool bAtomicAudioLocks;
 	int iLockedCPUSpeed;
 	bool bAutoSaveSymbolMap;
 	bool bCacheFullIsoInRam;

Core/HW/StereoResampler.cpp

@@ -71,20 +71,16 @@ unsigned int StereoResampler::MixerFifo::Mix(short* samples, unsigned int numSam
 	u32 indexR = Common::AtomicLoad(m_indexR);
 	u32 indexW = Common::AtomicLoad(m_indexW);
 
+	// Drift prevention mechanism
 	float numLeft = (float)(((indexW - indexR) & INDEX_MASK) / 2);
 	m_numLeftI = (numLeft + m_numLeftI*(CONTROL_AVG - 1)) / CONTROL_AVG;
 	float offset = (m_numLeftI - LOW_WATERMARK) * CONTROL_FACTOR;
 	if (offset > MAX_FREQ_SHIFT) offset = MAX_FREQ_SHIFT;
 	if (offset < -MAX_FREQ_SHIFT) offset = -MAX_FREQ_SHIFT;
 
-	// render numleft sample pairs to samples[]
-	// advance indexR with sample position
-	// remember fractional offset
-
-
 	float aid_sample_rate = m_input_sample_rate + offset;
 	
-	/*
+	/* Hm?
 	u32 framelimit = SConfig::GetInstance().m_Framelimit;
 	if (consider_framelimit && framelimit > 1) {
 		aid_sample_rate = aid_sample_rate * (framelimit - 1) * 5 / 59.994;
@@ -96,21 +92,14 @@ unsigned int StereoResampler::MixerFifo::Mix(short* samples, unsigned int numSam
 	// TODO: Add a fast path for 1:1.
 	for (; currentSample < numSamples * 2 && ((indexW - indexR) & INDEX_MASK) > 2; currentSample += 2) {
 		u32 indexR2 = indexR + 2; //next sample
-
 		s16 l1 = m_buffer[indexR & INDEX_MASK]; //current
-		s16 l2 = m_buffer[indexR2 & INDEX_MASK]; //next
-		int sampleL = ((l1 << 16) + (l2 - l1) * (u16)m_frac) >> 16;
-		sampleL += samples[currentSample + 1];
-		MathUtil::Clamp(&sampleL, -32767, 32767);
-		samples[currentSample + 1] = sampleL;
-
 		s16 r1 = m_buffer[(indexR + 1) & INDEX_MASK]; //current
+		s16 l2 = m_buffer[indexR2 & INDEX_MASK]; //next
 		s16 r2 = m_buffer[(indexR2 + 1) & INDEX_MASK]; //next
+		int sampleL = ((l1 << 16) + (l2 - l1) * (u16)m_frac) >> 16;
 		int sampleR = ((r1 << 16) + (r2 - r1) * (u16)m_frac) >> 16;
-		sampleR += samples[currentSample];
-		MathUtil::Clamp(&sampleR, -32767, 32767);
-		samples[currentSample] = sampleR;
-
+		samples[currentSample] = clamp_s16(sampleL);  // Do we even need to clamp after interpolation?
+		samples[currentSample + 1] = clamp_s16(sampleR);
 		m_frac += ratio;
 		indexR += 2 * (u16)(m_frac >> 16);
 		m_frac &= 0xffff;
@@ -120,23 +109,19 @@ unsigned int StereoResampler::MixerFifo::Mix(short* samples, unsigned int numSam
 
 	// Padding with the last value to reduce clicking
 	short s[2];
-	s[0] = m_buffer[(indexR - 1) & INDEX_MASK];
-	s[1] = m_buffer[(indexR - 2) & INDEX_MASK];
+	s[0] = clamp_s16(m_buffer[(indexR - 1) & INDEX_MASK]);
+	s[1] = clamp_s16(m_buffer[(indexR - 2) & INDEX_MASK]);
 	for (; currentSample < numSamples * 2; currentSample += 2) {
-		int sampleR = s[0] + samples[currentSample];
-		MathUtil::Clamp(&sampleR, -32767, 32767);
-		samples[currentSample] = sampleR;
-		int sampleL = s[1] + samples[currentSample + 1];
-		MathUtil::Clamp(&sampleL, -32767, 32767);
-		samples[currentSample + 1] = sampleL;
+		samples[currentSample] = s[0];
+		samples[currentSample + 1] = s[1];
 	}
 
 	// Flush cached variable
 	Common::AtomicStore(m_indexR, indexR);
 
-	if (realSamples != numSamples * 2) {
-		ILOG("Underrun! %i / %i", realSamples / 2, numSamples);
-	}
+	//if (realSamples != numSamples * 2) {
+	//	ILOG("Underrun! %i / %i", realSamples / 2, numSamples);
+	//}
 
 	return realSamples / 2;
 }
@@ -145,8 +130,6 @@ unsigned int StereoResampler::Mix(short* samples, unsigned int num_samples, bool
 	if (!samples)
 		return 0;
 
-	lock_guard lk(m_csMixing);
-	memset(samples, 0, num_samples * 2 * sizeof(short));
 	return m_dma_mixer.Mix(samples, num_samples, consider_framelimit, sample_rate);
 }
 

Core/HW/StereoResampler.h

@@ -57,8 +57,6 @@ public:
 
 	void SetDMAInputSampleRate(unsigned int rate);
 
-	recursive_mutex& MixerCritical() { return m_csMixing; }
-
 	float GetCurrentSpeed() const { return m_speed; }
 	void UpdateSpeed(volatile float val) { m_speed = val; }
 
@@ -99,7 +97,5 @@ protected:
 	MixerFifo m_dma_mixer;
 	unsigned int m_sampleRate;
 
-	recursive_mutex m_csMixing;
-
 	volatile float m_speed; // Current rate of the emulation (1.0 = 100% speed)
 };

UI/GameSettingsScreen.cpp

@@ -428,8 +428,6 @@ void GameSettingsScreen::CreateViews() {
 #endif
 	systemSettings->Add(new CheckBox(&g_Config.bSetRoundingMode, s->T("Respect FPU rounding (disable for old GEB saves)")))->OnClick.Handle(this, &GameSettingsScreen::OnJitAffectingSetting);
 
-	systemSettings->Add(new CheckBox(&g_Config.bAtomicAudioLocks, s->T("Atomic Audio locks (experimental)")))->SetEnabled(!PSP_IsInited());
-
 	systemSettings->Add(new ItemHeader(s->T("Developer Tools")));
 	systemSettings->Add(new Choice(s->T("Developer Tools")))->OnClick.Handle(this, &GameSettingsScreen::OnDeveloperTools);
 

UI/NativeApp.cpp

@@ -219,8 +219,10 @@ std::string NativeQueryConfig(std::string query) {
 
 		sprintf(temp, "%i", scale);
 		return std::string(temp);
+	} else if (query == "force44khz") {
+		return std::string("0");
 	} else {
-		return std::string("");
+		return "";
 	}
 }