From 471bb025b2a0718aca3eec33aef73df26c8d680a Mon Sep 17 00:00:00 2001
From: hrydgard <hrydgard@gmail.com>
Date: Sat, 16 Aug 2008 22:28:33 +0000
Subject: [PATCH] gigaherz' improved resampler

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@228 8ced0084-cf51-0410-be5f-012b33b47a6e
---
 .../Plugins/Plugin_DSP_HLE/Src/PCHW/Mixer.cpp | 68 ++++++++++++++++---
 1 file changed, 60 insertions(+), 8 deletions(-)

diff --git a/Source/Plugins/Plugin_DSP_HLE/Src/PCHW/Mixer.cpp b/Source/Plugins/Plugin_DSP_HLE/Src/PCHW/Mixer.cpp
index e2745d1bbf..2aa40a5eec 100644
--- a/Source/Plugins/Plugin_DSP_HLE/Src/PCHW/Mixer.cpp
+++ b/Source/Plugins/Plugin_DSP_HLE/Src/PCHW/Mixer.cpp
@@ -78,7 +78,10 @@ void Mixer_PushSamples(short *buffer, int num_stereo_samples, int sample_rate) {
 //	if (!f)
 //		f = fopen("d:\\hello.raw", "wb");
 //	fwrite(buffer, num_stereo_samples * 4, 1, f);
-	static int fraction = 0;
+
+	static int PV1l=0,PV2l=0,PV3l=0,PV4l=0;
+	static int PV1r=0,PV2r=0,PV3r=0,PV4r=0;
+	static int acc=0;
 
 	while (queue_size > queue_maxlength / 2) {
 #ifdef _WIN32
@@ -86,14 +89,63 @@ void Mixer_PushSamples(short *buffer, int num_stereo_samples, int sample_rate) {
 #endif
 		Sleep(0);
 	}
+
+	//convert into config option?
+	const int mode = 2;
+
 	push_sync.Enter();
-	for (int i = 0; i < num_stereo_samples * 2; i++) {
-		while (fraction < 65536) {
-			sample_queue.push(buffer[i]);
-			queue_size++;
-			fraction += (65536ULL * sample_rate) / 48000;
+	while (num_stereo_samples) 
+	{
+		acc += sample_rate;
+ 		while (num_stereo_samples && (acc>=48000))
+ 		{
+ 			PV4l=PV3l;
+ 			PV3l=PV2l;
+ 			PV2l=PV1l;
+ 			PV1l=*(buffer++); //32bit processing
+ 			PV4r=PV3r;
+ 			PV3r=PV2r;
+ 			PV2r=PV1r;
+ 			PV1r=*(buffer++); //32bit processing
+			num_stereo_samples--;
+ 			acc-=48000;
+ 		}
+
+		// defaults to nearest
+		s32 DataL = PV1l;
+		s32 DataR = PV1r;
+
+ 		if (mode==1) //linear
+ 		{
+			DataL = PV1l + ((PV2l - PV1l)*acc)/48000;
+			DataR = PV1r + ((PV2r - PV1r)*acc)/48000;
 		}
-		fraction &= 0xFFFF;
-	}
+ 		else if (mode==2) //cubic
+ 		{
+ 			s32 a0l = PV1l - PV2l - PV4l + PV3l;
+ 			s32 a0r = PV1r - PV2r - PV4r + PV3r;
+ 			s32 a1l = PV4l - PV3l - a0l;
+ 			s32 a1r = PV4r - PV3r - a0r;
+ 			s32 a2l = PV1l - PV4l;
+ 			s32 a2r = PV1r - PV4r;
+ 			s32 a3l = PV2l;
+ 			s32 a3r = PV2r;
+ 
+ 			s32 t0l = ((a0l    )*acc)/48000;
+ 			s32 t0r = ((a0r    )*acc)/48000;
+ 			s32 t1l = ((t0l+a1l)*acc)/48000;
+ 			s32 t1r = ((t0r+a1r)*acc)/48000;
+ 			s32 t2l = ((t1l+a2l)*acc)/48000;
+ 			s32 t2r = ((t1r+a2r)*acc)/48000;
+ 			s32 t3l = ((t2l+a3l));
+ 			s32 t3r = ((t2r+a3r));
+ 
+ 			DataL = t3l;
+ 			DataR = t3r;
+		}
+		sample_queue.push(DataL);
+		sample_queue.push(DataR);
+		queue_size++;
+ 	}
 	push_sync.Leave();
 }