From d961f6f498aff69f21b75feba4ddb715de9a2ddf Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Tue, 17 May 2022 02:38:13 -0500
Subject: [PATCH] SegaPCM: fix samples bigger than 64KB

---
 src/engine/platform/segapcm.cpp | 12 ++++++++----
 src/engine/vgmOps.cpp           |  7 ++++---
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/engine/platform/segapcm.cpp b/src/engine/platform/segapcm.cpp
index a16f0e161..bbe28060c 100644
--- a/src/engine/platform/segapcm.cpp
+++ b/src/engine/platform/segapcm.cpp
@@ -181,11 +181,13 @@ int DivPlatformSegaPCM::dispatch(DivCommand c) {
         chan[c.chan].macroInit(ins);
         if (dumpWrites) { // Sega PCM writes
           DivSample* s=parent->getSample(chan[c.chan].pcm.sample);
+          int actualLength=(int)s->length8;
+          if (actualLength>0xfeff) actualLength=0xfeff;
           addWrite(0x10086+(c.chan<<3),3+((s->offSegaPCM>>16)<<3));
           addWrite(0x10084+(c.chan<<3),(s->offSegaPCM)&0xff);
           addWrite(0x10085+(c.chan<<3),(s->offSegaPCM>>8)&0xff);
-          addWrite(0x10006+(c.chan<<3),MIN(255,((s->offSegaPCM&0xffff)+s->length8-1)>>8));
-          if (s->loopStart<0 || s->loopStart>=(int)s->length8) {
+          addWrite(0x10006+(c.chan<<3),MIN(255,((s->offSegaPCM&0xffff)+actualLength-1)>>8));
+          if (s->loopStart<0 || s->loopStart>=actualLength) {
             addWrite(0x10086+(c.chan<<3),2+((s->offSegaPCM>>16)<<3));
           } else {
             int loopPos=(s->offSegaPCM&0xffff)+s->loopStart+s->loopOffP;
@@ -212,11 +214,13 @@ int DivPlatformSegaPCM::dispatch(DivCommand c) {
         chan[c.chan].furnacePCM=false;
         if (dumpWrites) { // Sega PCM writes
           DivSample* s=parent->getSample(chan[c.chan].pcm.sample);
+          int actualLength=(int)s->length8;
+          if (actualLength>65536) actualLength=65536;
           addWrite(0x10086+(c.chan<<3),3+((s->offSegaPCM>>16)<<3));
           addWrite(0x10084+(c.chan<<3),(s->offSegaPCM)&0xff);
           addWrite(0x10085+(c.chan<<3),(s->offSegaPCM>>8)&0xff);
-          addWrite(0x10006+(c.chan<<3),MIN(255,((s->offSegaPCM&0xffff)+s->length8-1)>>8));
-          if (s->loopStart<0 || s->loopStart>=(int)s->length8) {
+          addWrite(0x10006+(c.chan<<3),MIN(255,((s->offSegaPCM&0xffff)+actualLength-1)>>8));
+          if (s->loopStart<0 || s->loopStart>=actualLength) {
             addWrite(0x10086+(c.chan<<3),2+((s->offSegaPCM>>16)<<3));
           } else {
             int loopPos=(s->offSegaPCM&0xffff)+s->loopStart+s->loopOffP;
diff --git a/src/engine/vgmOps.cpp b/src/engine/vgmOps.cpp
index 383153fe7..35e59e94f 100644
--- a/src/engine/vgmOps.cpp
+++ b/src/engine/vgmOps.cpp
@@ -1348,14 +1348,15 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version) {
     size_t memPos=0;
     for (int i=0; i<song.sampleLen; i++) {
       DivSample* sample=song.sample[i];
-      if ((memPos&0xff0000)!=((memPos+sample->length8)&0xff0000)) {
+      unsigned int alignedSize=(sample->length8+0xff)&(~0xff);
+      if (alignedSize>65536) alignedSize=65536;
+      if ((memPos&0xff0000)!=((memPos+alignedSize)&0xff0000)) {
         memPos=(memPos+0xffff)&0xff0000;
       }
+      logV("- sample %d will be at %x with length %x",i,memPos,alignedSize);
       if (memPos>=16777216) break;
       sample->offSegaPCM=memPos;
-      unsigned int alignedSize=(sample->length8+0xff)&(~0xff);
       unsigned int readPos=0;
-      if (alignedSize>65536) alignedSize=65536;
       for (unsigned int j=0; j<alignedSize; j++) {
         if (readPos>=sample->length8) {
           if (sample->loopStart>=0 && sample->loopStart<(int)sample->length8) {