From 8b05e7abf019c391de912b8f5edf3918da34c78b Mon Sep 17 00:00:00 2001
From: Henrik Rydgard <hrydgard@gmail.com>
Date: Wed, 14 Jan 2015 00:45:12 +0100
Subject: [PATCH] Adjust the audio speed on non-60hz Android devices to
 compensate.

Greatly improves audio stability on Nexus S.

Fixes #6677 .
---
 Core/HW/StereoResampler.cpp | 17 +++++++++++++++++
 Core/HW/StereoResampler.h   |  5 +----
 UI/DevScreens.cpp           |  7 +++++++
 Windows/main.cpp            |  2 ++
 ios/main.mm                 |  2 ++
 native                      |  2 +-
 6 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/Core/HW/StereoResampler.cpp b/Core/HW/StereoResampler.cpp
index fdfcb4329..7edf2a037 100644
--- a/Core/HW/StereoResampler.cpp
+++ b/Core/HW/StereoResampler.cpp
@@ -20,6 +20,7 @@
 #include <string.h>
 
 #include "base/logging.h"
+#include "base/NativeApp.h"
 #include "Common/ChunkFile.h"
 #include "Common/MathUtil.h"
 #include "Common/Atomics.h"
@@ -30,6 +31,22 @@
 #include <emmintrin.h>
 #endif
 
+
+StereoResampler::StereoResampler()
+	: m_dma_mixer(this, 44100)
+{
+	// Some Android devices are v-synced to non-60Hz framerates. We simply timestretch audio to fit. 
+	// TODO: should only do this if auto frameskip is off?
+
+	float refresh = System_GetPropertyInt(SYSPROP_DISPLAY_REFRESH_RATE) / 1000.0f;
+
+	// If framerate is "close"...
+	if (refresh != 60.0f && refresh > 50.0f && refresh < 70.0f) {
+		m_dma_mixer.SetInputSampleRate((int)(44100 * (refresh / 60.0f)));
+	}
+}
+
+
 inline void ClampBufferToS16(s16 *out, const s32 *in, size_t size) {
 #ifdef _M_SSE
 	// Size will always be 16-byte aligned as the hwBlockSize is.
diff --git a/Core/HW/StereoResampler.h b/Core/HW/StereoResampler.h
index 38cf449f9..504eed158 100644
--- a/Core/HW/StereoResampler.h
+++ b/Core/HW/StereoResampler.h
@@ -39,10 +39,7 @@
 class StereoResampler {
 
 public:
-	StereoResampler()
-		: m_dma_mixer(this, 44100)
-	{
-	}
+	StereoResampler();
 
 	virtual ~StereoResampler() {}
 
diff --git a/UI/DevScreens.cpp b/UI/DevScreens.cpp
index 61b3eb2cd..f3132bf0c 100644
--- a/UI/DevScreens.cpp
+++ b/UI/DevScreens.cpp
@@ -330,8 +330,15 @@ void SystemInfoScreen::CreateViews() {
 	deviceSpecs->Add(new InfoItem("Frames per buffer", StringFromFormat("%d", System_GetPropertyInt(SYSPROP_AUDIO_FRAMES_PER_BUFFER))));
 	deviceSpecs->Add(new InfoItem("Optimal sample rate", StringFromFormat("%d Hz", System_GetPropertyInt(SYSPROP_AUDIO_OPTIMAL_SAMPLE_RATE))));
 	deviceSpecs->Add(new InfoItem("Optimal frames per buffer", StringFromFormat("%d", System_GetPropertyInt(SYSPROP_AUDIO_OPTIMAL_FRAMES_PER_BUFFER))));
+
+	deviceSpecs->Add(new ItemHeader("Display Information"));
+	deviceSpecs->Add(new InfoItem("Native Resolution", StringFromFormat("%dx%d",
+		System_GetPropertyInt(SYSPROP_DISPLAY_XRES),
+		System_GetPropertyInt(SYSPROP_DISPLAY_YRES))));
+	deviceSpecs->Add(new InfoItem("Refresh rate", StringFromFormat("%0.3f Hz", (float)System_GetPropertyInt(SYSPROP_DISPLAY_REFRESH_RATE) / 1000.0f)));
 #endif
 
+
 	deviceSpecs->Add(new ItemHeader("Version Information"));
 	std::string apiVersion = thin3d->GetInfoString(T3DInfo::APIVERSION);
 	apiVersion.resize(30);
diff --git a/Windows/main.cpp b/Windows/main.cpp
index de38e42e3..dcf1c222b 100644
--- a/Windows/main.cpp
+++ b/Windows/main.cpp
@@ -263,6 +263,8 @@ int System_GetPropertyInt(SystemProperty prop) {
 	switch (prop) {
 	case SYSPROP_AUDIO_SAMPLE_RATE:
 		return winAudioBackend ? winAudioBackend->GetSampleRate() : -1;
+	case SYSPROP_DISPLAY_REFRESH_RATE:
+		return 60000;
 	default:
 		return -1;
 	}
diff --git a/ios/main.mm b/ios/main.mm
index abc4887c5..def51c996 100644
--- a/ios/main.mm
+++ b/ios/main.mm
@@ -26,6 +26,8 @@ int System_GetPropertyInt(SystemProperty prop) {
   switch (prop) {
   case SYSPROP_AUDIO_SAMPLE_RATE:
     return 44100;
+  case SYSPROP_DISPLAY_REFRESH_RATE:
+    return 60000;
   default:
     return -1;
   }
diff --git a/native b/native
index 477e0e89f..d2f95b919 160000
--- a/native
+++ b/native
@@ -1 +1 @@
-Subproject commit 477e0e89f9269b573edbfbc84c22199c4d449203
+Subproject commit d2f95b91909418d07cb6cdd3f6b8f7cf5ad4dc09