CDImage: Support SBI replacement subchannel Q for cue/bin images

src/common/cd_subchannel_replacement.cpp

@@ -0,0 +1,97 @@
+#include "cd_subchannel_replacement.h"
+#include "YBaseLib/Log.h"
+#include <memory>
+Log_SetChannel(CDSubChannelReplacement);
+
+#pragma pack(push, 1)
+struct SBIFileEntry
+{
+  u8 minute_bcd;
+  u8 second_bcd;
+  u8 frame_bcd;
+  u8 type;
+  u8 data[10];
+};
+#pragma pack(pop)
+
+CDSubChannelReplacement::CDSubChannelReplacement() = default;
+
+CDSubChannelReplacement::~CDSubChannelReplacement() = default;
+
+static constexpr u32 MSFToLBA(u8 minute_bcd, u8 second_bcd, u8 frame_bcd)
+{
+  const u8 minute = PackedBCDToBinary(minute_bcd);
+  const u8 second = PackedBCDToBinary(second_bcd);
+  const u8 frame = PackedBCDToBinary(frame_bcd);
+
+  return (ZeroExtend32(minute) * 60 * 75) + (ZeroExtend32(second) * 75) + ZeroExtend32(frame);
+}
+
+bool CDSubChannelReplacement::LoadSBI(const char* path)
+{
+  std::unique_ptr<std::FILE, void (*)(std::FILE*)> fp(std::fopen(path, "rb"), [](std::FILE* fp) { std::fclose(fp); });
+  if (!fp)
+    return false;
+
+  char header[4];
+  if (std::fread(header, sizeof(header), 1, fp.get()) != 1)
+  {
+    Log_ErrorPrintf("Failed to read header for '%s'", path);
+    return true;
+  }
+
+  static constexpr char expected_header[] = {'S', 'B', 'I', '\0'};
+  if (std::memcmp(header, expected_header, sizeof(header)) != 0)
+  {
+    Log_ErrorPrintf("Invalid header in '%s'", path);
+    return true;
+  }
+
+  SBIFileEntry entry;
+  while (std::fread(&entry, sizeof(entry), 1, fp.get()) == 1)
+  {
+    if (!IsValidPackedBCD(entry.minute_bcd) || !IsValidPackedBCD(entry.second_bcd) ||
+        !IsValidPackedBCD(entry.frame_bcd))
+    {
+      Log_ErrorPrintf("Invalid position [%02x:%02x:%02x] in '%s'", entry.minute_bcd, entry.second_bcd, entry.frame_bcd,
+                      path);
+      return false;
+    }
+
+    if (entry.type != 1)
+    {
+      Log_ErrorPrintf("Invalid type 0x%02X in '%s'", path);
+      return false;
+    }
+
+    const u32 lba = MSFToLBA(entry.minute_bcd, entry.second_bcd, entry.frame_bcd);
+
+    ReplacementData subq_data;
+    std::copy_n(entry.data, countof(entry.data), subq_data.data());
+
+    // generate an invalid crc by flipping all bits from the valid crc (will never collide)
+    const u16 crc = CDImage::SubChannelQ::ComputeCRC(subq_data.data()) ^ 0xFFFF;
+    subq_data[10] = Truncate8(crc);
+    subq_data[11] = Truncate8(crc >> 8);
+
+    m_replacement_subq.emplace(lba, subq_data);
+  }
+
+  Log_InfoPrintf("Loaded %zu replacement sectors from '%s'", m_replacement_subq.size(), path);
+  return true;
+}
+
+bool CDSubChannelReplacement::GetReplacementSubChannelQ(u8 minute_bcd, u8 second_bcd, u8 frame_bcd, u8* subq_data) const
+{
+  return GetReplacementSubChannelQ(MSFToLBA(minute_bcd, second_bcd, frame_bcd), subq_data);
+}
+
+bool CDSubChannelReplacement::GetReplacementSubChannelQ(u32 lba, u8* subq_data) const
+{
+  ReplacementMap::const_iterator iter = m_replacement_subq.find(lba);
+  if (iter == m_replacement_subq.end())
+    return false;
+
+  std::copy(iter->second.begin(), iter->second.end(), subq_data);
+  return true;
+}