From f13676cfd3b48f36b24f95178743af5a2c377b06 Mon Sep 17 00:00:00 2001
From: qwertymodo <qwertymodo@qwertymodo.com>
Date: Thu, 3 Nov 2016 13:10:01 -0700
Subject: [PATCH] Fix MSU-1 sample buffer size

---
 apu/apu.cpp | 17 +++++++++++++----
 ppu.cpp     |  1 +
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/apu/apu.cpp b/apu/apu.cpp
index c897e90f..6a83d300 100644
--- a/apu/apu.cpp
+++ b/apu/apu.cpp
@@ -336,10 +336,19 @@ bool8 S9xMixSamples (uint8 *buffer, int sample_count)
 			{
 				if (msu::resampler->avail() >= sample_count)
 				{
-					uint8 *msu_sample = new uint8[sizeof(dest)];
+					uint8 *msu_sample = new uint8[sample_count * 2];
 					msu::resampler->read((short *)msu_sample, sample_count);
-					for(uint32 i = 0; i < sizeof(dest); ++i)
-						dest[i] += msu_sample[i];
+					for (uint32 i = 0; i < sample_count * 2; i += 2)
+					{
+						int16 s1, s2;
+						((uint8 *)&s1)[0] = dest[i];
+						((uint8 *)&s1)[1] = dest[i + 1];
+						((uint8 *)&s2)[0] = dest[i];
+						((uint8 *)&s2)[1] = dest[i + 1];
+						s1 += s2;
+						dest[i] = ((uint8 *)&s1)[0];
+						dest[i+1] = ((uint8 *)&s1)[1];
+					}
 				}
 			}
 		}
@@ -481,7 +490,7 @@ bool8 S9xInitSound (int buffer_ms, int lag_ms)
 	if (Settings.SixteenBitSound)
 		spc::buffer_size <<= 1;
 	if (Settings.MSU1)
-		msu::buffer_size = buffer_ms * 44100 / 1000;
+		msu::buffer_size = (buffer_ms * 44100 / 1000) << 2; // 16-bit, Stereo
 
 	printf("Sound buffer size: %d (%d samples)\n", spc::buffer_size, sample_count);
 
diff --git a/ppu.cpp b/ppu.cpp
index 682fd880..fe0328fa 100644
--- a/ppu.cpp
+++ b/ppu.cpp
@@ -1130,6 +1130,7 @@ uint8 S9xGetPPU (uint16 Address)
 	if ((Address & 0xffc0) == 0x2140) // APUIO0, APUIO1, APUIO2, APUIO3
 		// read_port will run the APU until given APU time before reading value
 		return (S9xAPUReadPort(Address & 3));
+	else
 	if (Address <= 0x2183)
     {
 		uint8	byte;