Patches for Resident Evil 2/3 audio issues

Data/Sys/GameSettings/GHAE08.ini

@@ -0,0 +1,16 @@
+# GHAE08 - Resident Evil 2
+
+[OnFrame]
+# Work around a game bug that causes background sounds to be zeroed during load.
+# The bug was masked on real hardware by dcache. This patch fully fixes the bug
+# and should also work on real hardware. Dolphin doesn't emulate dcache because
+# the performance hit would be huge.
+$Fix audio issues
+# main.dol
+0x800339E4:dword:0x60000000
+# leon.rel
+0x8055ACBC:dword:0x60000000:0x4BAA8445
+# claire.rel
+0x8055AB54:dword:0x60000000:0x4BAA85AD
+[OnFrame_Enabled]
+$Fix audio issues

Data/Sys/GameSettings/GHAJ08.ini

@@ -0,0 +1,16 @@
+# GHAJ08 - Biohazard 2
+
+[OnFrame]
+# Work around a game bug that causes background sounds to be zeroed during load.
+# The bug was masked on real hardware by dcache. This patch fully fixes the bug
+# and should also work on real hardware. Dolphin doesn't emulate dcache because
+# the performance hit would be huge.
+$Fix audio issues
+# main.dol
+0x80065FFC:dword:0x60000000
+# leon.rel
+0x805C5CC4:dword:0x60000000:0x4BA3D43D
+# claire.rel
+0x805C5BFC:dword:0x60000000:0x4BA3D505
+[OnFrame_Enabled]
+$Fix audio issues

Data/Sys/GameSettings/GHAP08.ini

@@ -0,0 +1,32 @@
+# GHAP08 - Resident Evil 2
+
+[OnFrame]
+# Work around a game bug that causes background sounds to be zeroed during load.
+# The bug was masked on real hardware by dcache. This patch fully fixes the bug
+# and should also work on real hardware. Dolphin doesn't emulate dcache because
+# the performance hit would be huge.
+$Fix audio issues
+# main.dol
+0x80033D60:dword:0x60000000
+# leon.rel
+0x8055C5F8:dword:0x60000000:0x4BAA6B09
+# claire.rel
+0x8055C490:dword:0x60000000:0x4BAA6C71
+# leon_g.rel
+0x8055C3B8:dword:0x60000000:0x4BAA6D49
+# claire_g.rel
+0x8055C328:dword:0x60000000:0x4BAA6DD9
+# leon_f.rel
+0x8055D188:dword:0x60000000:0x4BAA5F79
+# claire_f.rel
+0x8055D068:dword:0x60000000:0x4BAA6099
+# leon_s.rel
+0x8055D100:dword:0x60000000:0x4BAA6001
+# claire_s.rel
+0x8055D064:dword:0x60000000:0x4BAA609D
+# leon_i.rel
+0x8055CFDC:dword:0x60000000:0x4BAA6125
+# claire_i.rel
+0x8055CEBC:dword:0x60000000:0x4BAA6245
+[OnFrame_Enabled]
+$Fix audio issues

Data/Sys/GameSettings/GLEE08.ini

@@ -0,0 +1,12 @@
+# GLEE08 - Resident Evil 3: Nemesis
+
+[OnFrame]
+# Work around a game bug that causes background sounds to be zeroed during load.
+# The bug was masked on real hardware by dcache. This patch fully fixes the bug
+# and should also work on real hardware. Dolphin doesn't emulate dcache because
+# the performance hit would be huge.
+$Fix audio issues
+# main.dol
+0x80150E94:dword:0x60000000
+[OnFrame_Enabled]
+$Fix audio issues

Data/Sys/GameSettings/GLEJ08.ini

@@ -0,0 +1,12 @@
+# GLEJ08 - BioHazard 3: Last Escape
+
+[OnFrame]
+# Work around a game bug that causes background sounds to be zeroed during load.
+# The bug was masked on real hardware by dcache. This patch fully fixes the bug
+# and should also work on real hardware. Dolphin doesn't emulate dcache because
+# the performance hit would be huge.
+$Fix audio issues
+# main.dol
+0x8015110C:dword:0x60000000
+[OnFrame_Enabled]
+$Fix audio issues

Data/Sys/GameSettings/GLEP08.ini

@@ -0,0 +1,20 @@
+# GLEP08 - Resident Evil 3: Nemesis
+
+[OnFrame]
+# Work around a game bug that causes background sounds to be zeroed during load.
+# The bug was masked on real hardware by dcache. This patch fully fixes the bug
+# and should also work on real hardware. Dolphin doesn't emulate dcache because
+# the performance hit would be huge.
+$Fix audio issues
+# eng.rel
+0x8058C174:dword:0x60000000:0x4BA76F8D
+# ger.rel
+0x8058CE40:dword:0x60000000:0x4BA762C1
+# fra.rel
+0x8058D03C:dword:0x60000000:0x4BA760C5
+# spa.rel
+0x8058D024:dword:0x60000000:0x4BA760DD
+# ita.rel
+0x8058CEA4:dword:0x60000000:0x4BA7625D
+[OnFrame_Enabled]
+$Fix audio issues

Source/Core/Core/PatchEngine.cpp

@@ -90,6 +90,11 @@ void LoadPatchSection(const std::string& section, std::vector<Patch>& patches, I
           bool success = true;
           success &= TryParse(items[0], &pE.address);
           success &= TryParse(items[2], &pE.value);
+          if (items.size() >= 4)
+          {
+            success &= TryParse(items[3], &pE.comparand);
+            pE.conditional = true;
+          }
 
           const auto iter =
               std::find(s_patch_type_strings.begin(), s_patch_type_strings.end(), items[1]);
@@ -184,16 +189,20 @@ static void ApplyPatches(const std::vector<Patch>& patches)
       {
         u32 addr = entry.address;
         u32 value = entry.value;
+        u32 comparand = entry.comparand;
         switch (entry.type)
         {
         case PatchType::Patch8Bit:
-          PowerPC::HostWrite_U8(static_cast<u8>(value), addr);
+          if (!entry.conditional || PowerPC::HostRead_U8(addr) == static_cast<u8>(comparand))
+            PowerPC::HostWrite_U8(static_cast<u8>(value), addr);
           break;
         case PatchType::Patch16Bit:
-          PowerPC::HostWrite_U16(static_cast<u16>(value), addr);
+          if (!entry.conditional || PowerPC::HostRead_U16(addr) == static_cast<u16>(comparand))
+            PowerPC::HostWrite_U16(static_cast<u16>(value), addr);
           break;
         case PatchType::Patch32Bit:
-          PowerPC::HostWrite_U32(value, addr);
+          if (!entry.conditional || PowerPC::HostRead_U32(addr) == comparand)
+            PowerPC::HostWrite_U32(value, addr);
           break;
         default:
           // unknown patchtype

Source/Core/Core/PatchEngine.h

@@ -27,6 +27,8 @@ struct PatchEntry
   PatchType type = PatchType::Patch8Bit;
   u32 address = 0;
   u32 value = 0;
+  u32 comparand = 0;
+  bool conditional = false;
 };
 
 struct Patch