MSU1 fixes backported

The following fixes are backported from the Snes9x master branch:
- Release msu data and audio streams on exit, use unzClose when closing
- Fix MSU-1 channel swap on loop
- Ensure all MSU-1 reads are stereo channel aligned
- Clean up S9xMSU1Generate code
- Fix MSU1 swapping.
- Fix casting on MSU1 volume
- Get rid of "Unable to find msu file" console spam

source/snes9x/apu/apu.cpp

@@ -510,7 +510,7 @@ bool8 S9xInitSound (int buffer_ms, int lag_ms)
 		return (FALSE);
 	if (msu::landing_buffer)
 		delete[] msu::landing_buffer;
-	msu::landing_buffer = new uint8[msu::buffer_size * 2];
+	msu::landing_buffer = (uint8*) new uint32[msu::buffer_size / 2]; // Ensure 4-byte alignment
 	if (!msu::landing_buffer)
 		return (FALSE);
 
@@ -635,6 +635,8 @@ void S9xDeinitAPU (void)
 		delete[] msu::resample_buffer;
 		msu::resample_buffer = NULL;
 	}
+	
+	S9xMSU1DeInit();
 }
 
 static inline int S9xAPUGetClock (int32 cpucycles)

source/snes9x/apu/resampler.h

@@ -17,7 +17,7 @@ class Resampler : public ring_buffer
         {
         }
 
-        ~Resampler ()
+        virtual ~Resampler ()
         {
         }
 

source/snes9x/memmap.cpp

@@ -4082,7 +4082,10 @@ static bool8 ReadBPSPatch (Reader *r, long, int32 &rom_size)
 
 		switch((int)mode) {
 			case SourceRead:
-				while(length--) patched_rom[outputOffset++] = Memory.ROM[outputOffset];
+				while(length--) {
+					patched_rom[outputOffset] = Memory.ROM[outputOffset];
+					outputOffset++;
+				}
 				break;
 			case TargetRead:
 				while(length--) patched_rom[outputOffset++] = data[addr++];
@@ -4337,7 +4340,7 @@ void CMemory::CheckForAnyPatch (const char *rom_filename, bool8 header, int32 &r
 		}
 	}
 
-	// Mercurial Magic (MSU-1 distribution pack)
+    // Mercurial Magic (MSU-1 distribution pack)
 	if (strcasecmp(ext, "msu1") && strcasecmp(ext, ".msu1"))
 	{
 		_makepath(fname, drive, dir, name, "msu1");
@@ -4350,8 +4353,9 @@ void CMemory::CheckForAnyPatch (const char *rom_filename, bool8 header, int32 &r
 			{
 				printf(" in %s", fname);
 
-				ret = ReadBPSPatch(new unzReader(file), offset, rom_size);
+				Stream *s = new unzStream(msu1file);
-				unzCloseCurrentFile(file);
+				ret = ReadBPSPatch(s, offset, rom_size);
+				s->closeStream();
 
 				if (ret)
 					printf("!\n");

source/snes9x/msu1.cpp

@@ -200,7 +200,7 @@
 STREAM dataStream = NULL;
 STREAM audioStream = NULL;
 uint32 audioLoopPos;
-size_t partial_samples;
+size_t partial_frames;
 
 // Sample buffer
 int16 *bufPos, *bufBegin, *bufEnd;
@@ -239,17 +239,22 @@ static int unzFindExtension(unzFile &file, const char *ext, bool restart = TRUE,
 }
 #endif
 
-STREAM S9xMSU1OpenFile(char *msu_ext)
+STREAM S9xMSU1OpenFile(const char *msu_ext, bool skip_unpacked)
 {
     char filename[MAXPATHLEN];
 	sprintf(filename, "%s%s%s", Memory.ROMFilePath, Memory.ROMFilename, msu_ext);
     
-    STREAM file = OPEN_STREAM(filename, "rb");
+	STREAM file = 0;
-    if (file)
+
-        printf("Using msu file %s.\n", filename);
+	if (!skip_unpacked)
+	{
+		file = OPEN_STREAM(filename, "rb");
+		if (file)
+			printf("Using msu file %s.\n", filename);
+	}
 
 #ifdef UNZIP_SUPPORT
-    // look for msu file in .msu1 (Mercurial Magic pack) if not found in rom dir
+    // look for msu1 pack file in the rom or patch dir if msu data file not found in rom dir
     if (!file)
     {
         char zip_filename[MAXPATHLEN];
@@ -265,26 +270,28 @@ STREAM S9xMSU1OpenFile(char *msu_ext)
                 file = new unzStream(unzFile);
             }
             else
-                unzCloseCurrentFile(unzFile);
+                unzClose(unzFile);
         }
     }
 #endif
 
-    if(!file)
-        printf("Unable to find msu file %s.\n", filename);
-
     return file;
 }
 
-bool AudioOpen()
+static void AudioClose()
+{
+	if (audioStream)
+	{
+		CLOSE_STREAM(audioStream);
+		audioStream = NULL;
+	}
+}
+
+static bool AudioOpen()
 {
 	MSU1.MSU1_STATUS |= AudioError;
 
-    if (audioStream)
+	AudioClose();
-    {
-        CLOSE_STREAM(audioStream);
-        audioStream = NULL;
-    }
 
 	char ext[_MAX_EXT];
 	snprintf(ext, _MAX_EXT, "-%d.pcm", MSU1.MSU1_CURRENT_TRACK);
@@ -305,6 +312,8 @@ bool AudioOpen()
 		audioLoopPos = GET_LE32(&audioLoopPos);
 		audioLoopPos <<= 2;
 		audioLoopPos += 8;
+		
+		MSU1.MSU1_AUDIO_POS = 8;
 
 		MSU1.MSU1_STATUS &= ~AudioError;
 		return true;
@@ -313,13 +322,18 @@ bool AudioOpen()
 	return false;
 }
 
-bool DataOpen()
+static void DataClose()
 {
-    if (dataStream)
+	if (dataStream)
-    {
+	{
-        CLOSE_STREAM(dataStream);
+		CLOSE_STREAM(dataStream);
-        dataStream = NULL;
+		dataStream = NULL;
-    }
+	}
+}
+
+static bool DataOpen()
+{
+	DataClose();
 
     dataStream = S9xMSU1OpenFile(".msu");
 
@@ -347,19 +361,11 @@ void S9xResetMSU(void)
 	bufBegin			= 0;
 	bufEnd				= 0;
 
-	partial_samples = 0;
+	partial_frames = 0;
 
-    if (dataStream)
+	DataClose();
-    {
-        CLOSE_STREAM(dataStream);
-        dataStream = NULL;
-    }
 
-    if (audioStream)
+	AudioClose();
-    {
-        CLOSE_STREAM(audioStream);
-        audioStream = NULL;
-    }
 
 	Settings.MSU1 = S9xMSU1ROMExists();
 }
@@ -369,6 +375,13 @@ void S9xMSU1Init(void)
 	DataOpen();
 }
 
+void S9xMSU1DeInit(void)
+{
+	DataClose();
+	AudioClose();
+}
+
+
 bool S9xMSU1ROMExists(void)
 {
     STREAM s = S9xMSU1OpenFile(".msu");
@@ -384,7 +397,7 @@ bool S9xMSU1ROMExists(void)
 
 	if (unzFile)
 	{
-		unzCloseCurrentFile(unzFile);
+		unzClose(unzFile);
 		return true;
 	}
 #endif
@@ -393,31 +406,30 @@ bool S9xMSU1ROMExists(void)
 
 void S9xMSU1Generate(size_t sample_count)
 {
-	partial_samples += 4410 * sample_count;
+	partial_frames += 4410 * (sample_count / 2);
 
-	while (((uintptr_t)bufPos < (uintptr_t)bufEnd) && partial_samples > 3204)
+	while ((bufPos < (bufEnd - 2)) && partial_frames >= 3204)
 	{
 		if (MSU1.MSU1_STATUS & AudioPlaying && audioStream)
 		{
-			int16 sample;
+			int32 sample;
-            int bytes_read = READ_STREAM((char *)&sample, 2, audioStream);
+			int16* left = (int16*)&sample;
-			if (bytes_read == 2)
+			int16* right = left + 1;
-			{
-				sample = (int16)((double)(int16)GET_LE16(&sample) * (double)MSU1.MSU1_VOLUME / 255.0);
 
-				*(bufPos++) = sample;
+            int bytes_read = READ_STREAM((char *)&sample, 4, audioStream);
-				MSU1.MSU1_AUDIO_POS += 2;
+			if (bytes_read == 4)
-				partial_samples -= 3204;
+			{
+				*left = ((int32)(int16)GET_LE16(left) * MSU1.MSU1_VOLUME / 255);
+				*right = ((int32)(int16)GET_LE16(right) * MSU1.MSU1_VOLUME / 255);
+
+				*(bufPos++) = *left;
+                *(bufPos++) = *right;
+				MSU1.MSU1_AUDIO_POS += 4;
+				partial_frames -= 3204;
 			}
 			else
 			if (bytes_read >= 0)
 			{
-				sample = (int16)((double)(int16)GET_LE16(&sample) * (double)MSU1.MSU1_VOLUME / 255.0);
-
-				*(bufPos++) = sample;
-				MSU1.MSU1_AUDIO_POS += 2;
-				partial_samples -= 3204;
-
 				if (MSU1.MSU1_STATUS & AudioRepeating)
 				{
 					MSU1.MSU1_AUDIO_POS = audioLoopPos;
@@ -437,7 +449,8 @@ void S9xMSU1Generate(size_t sample_count)
 		else
 		{
 			MSU1.MSU1_STATUS &= ~(AudioPlaying | AudioRepeating);
-			partial_samples -= 3204;
+			partial_frames -= 3204;
+			*(bufPos++) = 0;
 			*(bufPos++) = 0;
 		}
 	}
@@ -449,7 +462,7 @@ uint8 S9xMSU1ReadPort(uint8 port)
 	switch (port)
 	{
 	case 0:
-		return MSU1.MSU1_STATUS;
+		return MSU1.MSU1_STATUS | MSU1_REVISION;
 	case 1:
     {
         if (MSU1.MSU1_STATUS & DataBusy)
@@ -594,5 +607,5 @@ void S9xMSU1PostLoadState(void)
 	bufBegin = 0;
 	bufEnd = 0;
 
-	partial_samples = 0;
+	partial_frames = 0;
 }

source/snes9x/msu1.h

@@ -196,6 +196,8 @@
 #include <stdint.h>
 #include <sys\stat.h>
 
+#define MSU1_REVISION 0x02
+
 struct SMSU1
 {
 	uint8	MSU1_STATUS;
@@ -211,8 +213,7 @@ struct SMSU1
 };
 
 enum SMSU1_FLAG {
-	Revision		= 0x02,	//max: 0x07
+	Revision		= 0x07,	// bitmask, not the actual version number
-	AudioResume		= 0x04,
 	AudioError		= 0x08,
 	AudioPlaying	= 0x10,
 	AudioRepeating	= 0x20,
@@ -230,8 +231,9 @@ extern struct SMSU1	MSU1;
 
 void S9xResetMSU(void);
 void S9xMSU1Init(void);
+void S9xMSU1DeInit(void);
 bool S9xMSU1ROMExists(void);
-STREAM S9xMSU1OpenFile(char *msu_ext);
+STREAM S9xMSU1OpenFile(const char *msu_ext, bool skip_unpacked = FALSE);
 void S9xMSU1Init(void);
 void S9xMSU1Generate(size_t sample_count);
 uint8 S9xMSU1ReadPort(uint8 port);