From d13542f12be58ec3dd4381cf25cc59c951c110e7 Mon Sep 17 00:00:00 2001
From: twinaphex <libretro@gmail.com>
Date: Sat, 24 Aug 2013 05:10:14 +0200
Subject: [PATCH] (Android) Detects buffer size properly now on Android 4.2 and
 up - bases requested latency on this. Old fallback applies for non-4.2

---
 .../retroarch/browser/MainMenuActivity.java   | 28 +++++++++++++++++--
 audio/opensl.c                                |  2 ++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/android/phoenix/src/org/retroarch/browser/MainMenuActivity.java b/android/phoenix/src/org/retroarch/browser/MainMenuActivity.java
index d0fa8531c8..1c0491ec53 100644
--- a/android/phoenix/src/org/retroarch/browser/MainMenuActivity.java
+++ b/android/phoenix/src/org/retroarch/browser/MainMenuActivity.java
@@ -163,6 +163,18 @@ public class MainMenuActivity extends PreferenceActivity {
 		return Integer.parseInt(manager
 				.getProperty(AudioManager.PROPERTY_OUTPUT_SAMPLE_RATE));
 	}
+	
+	@TargetApi(17)
+	public static int getLowLatencyBufferSize() {
+		AudioManager manager = (AudioManager) MainMenuActivity.getInstance()
+				.getApplicationContext()
+				.getSystemService(Context.AUDIO_SERVICE);
+		int buffersize = Integer.parseInt(manager
+				.getProperty(AudioManager.PROPERTY_OUTPUT_FRAMES_PER_BUFFER));
+		
+		Log.i(TAG, "Queried ideal buffer size: " + buffersize);
+		return buffersize;
+	}
 
 	public static int getOptimalSamplingRate() {
 		int ret;
@@ -251,8 +263,20 @@ public class MainMenuActivity extends PreferenceActivity {
 				prefs.getBoolean("audio_rate_control", true));
 		config.setInt("audio_out_rate",
 				MainMenuActivity.getOptimalSamplingRate());
-		config.setInt("audio_latency",
-				prefs.getBoolean("audio_high_latency", false) ? 160 : 64);
+		
+		int buffersize = 0;
+		
+		if (android.os.Build.VERSION.SDK_INT >= 17) {
+			buffersize = getLowLatencyBufferSize();
+			if (config.getBoolean("audio_high_latency") == false) {
+				config.setInt("audio_latency", buffersize / 32);
+			}
+		}
+		else {
+			config.setInt("audio_latency",
+					prefs.getBoolean("audio_high_latency", false) ? 160 : 64);		
+		}
+
 		config.setBoolean("audio_enable",
 				prefs.getBoolean("audio_enable", true));
 		config.setBoolean("video_smooth",
diff --git a/audio/opensl.c b/audio/opensl.c
index 068e42a7a2..06362baab9 100644
--- a/audio/opensl.c
+++ b/audio/opensl.c
@@ -115,6 +115,8 @@ static void *sl_init(const char *device, unsigned rate, unsigned latency)
    if (!sl)
       goto error;
 
+   RARCH_LOG("[SLES ] : Requested audio latency: %dms...", latency);
+
    GOTO_IF_FAIL(slCreateEngine(&sl->engine_object, 0, NULL, 0, NULL, NULL));
    GOTO_IF_FAIL(SLObjectItf_Realize(sl->engine_object, SL_BOOLEAN_FALSE));
    GOTO_IF_FAIL(SLObjectItf_GetInterface(sl->engine_object, SL_IID_ENGINE, &sl->engine));