CDImage: Add support for loading mds/mdf images

src/common/CMakeLists.txt

@@ -17,6 +17,7 @@ add_library(common
   cd_image_hasher.cpp
   cd_image_hasher.h
   cd_image_memory.cpp
+  cd_image_mds.cpp
   cd_subchannel_replacement.cpp
   cd_subchannel_replacement.h
   cd_xa.cpp

src/common/cd_image.cpp

@@ -46,6 +46,10 @@ std::unique_ptr<CDImage> CDImage::Open(const char* filename)
   {
     return OpenEcmImage(filename);
   }
+  else if (CASE_COMPARE(extension, ".mds") == 0)
+  {
+    return OpenMdsImage(filename);
+  }
 
 #undef CASE_COMPARE
 

src/common/cd_image.h

@@ -196,6 +196,7 @@ public:
   static std::unique_ptr<CDImage> OpenCueSheetImage(const char* filename);
   static std::unique_ptr<CDImage> OpenCHDImage(const char* filename);
   static std::unique_ptr<CDImage> OpenEcmImage(const char* filename);
+  static std::unique_ptr<CDImage> OpenMdsImage(const char* filename);
   static std::unique_ptr<CDImage>
   CreateMemoryImage(CDImage* image, ProgressCallback* progress = ProgressCallback::NullProgressCallback);
 

src/common/cd_image_mds.cpp

@@ -0,0 +1,267 @@
+#include "assert.h"
+#include "cd_image.h"
+#include "cd_subchannel_replacement.h"
+#include "file_system.h"
+#include "log.h"
+#include <algorithm>
+#include <cerrno>
+#include <map>
+Log_SetChannel(CDImageMds);
+
+#pragma pack(push, 1)
+struct TrackEntry
+{
+  u8 track_type;
+  u8 has_subchannel_data;
+  u8 unk1;
+  u8 unk2;
+  u8 track_number;
+  u8 unk3[4];
+  u8 start_m;
+  u8 start_s;
+  u8 start_f;
+  u32 extra_offset;
+  u8 unk4[24];
+  u32 track_offset_in_mdf;
+  u8 unk5[36];
+};
+static_assert(sizeof(TrackEntry) == 0x50, "TrackEntry is 0x50 bytes");
+#pragma pack(pop)
+
+class CDImageMds : public CDImage
+{
+public:
+  CDImageMds();
+  ~CDImageMds() override;
+
+  bool OpenAndParse(const char* filename);
+
+  bool ReadSubChannelQ(SubChannelQ* subq) override;
+  bool HasNonStandardSubchannel() const override;
+
+protected:
+  bool ReadSectorFromIndex(void* buffer, const Index& index, LBA lba_in_index) override;
+
+private:
+  std::FILE* m_mdf_file = nullptr;
+  u64 m_mdf_file_position = 0;
+  CDSubChannelReplacement m_sbi;
+};
+
+CDImageMds::CDImageMds() = default;
+
+CDImageMds::~CDImageMds()
+{
+  if (m_mdf_file)
+    std::fclose(m_mdf_file);
+}
+
+bool CDImageMds::OpenAndParse(const char* filename)
+{
+  std::FILE* mds_fp = FileSystem::OpenCFile(filename, "rb");
+  if (!mds_fp)
+  {
+    Log_ErrorPrintf("Failed to open mds '%s': errno %d", filename, errno);
+    return false;
+  }
+
+  std::optional<std::vector<u8>> mds_data_opt(FileSystem::ReadBinaryFile(mds_fp));
+  std::fclose(mds_fp);
+  if (!mds_data_opt.has_value() || mds_data_opt->size() < 0x54)
+  {
+    Log_ErrorPrintf("Failed to read mds file '%s'", filename);
+    return false;
+  }
+
+  std::string mdf_filename(FileSystem::ReplaceExtension(filename, "mdf"));
+  m_mdf_file = FileSystem::OpenCFile(mdf_filename.c_str(), "rb");
+  if (!m_mdf_file)
+  {
+    Log_ErrorPrintf("Failed to open mdf file '%s': errno %d", mdf_filename.c_str(), errno);
+    return false;
+  }
+
+  const std::vector<u8>& mds = mds_data_opt.value();
+  static constexpr char expected_signature[] = "MEDIA DESCRIPTOR";
+  if (std::memcmp(&mds[0], expected_signature, sizeof(expected_signature) - 1) != 0)
+  {
+    Log_ErrorPrintf("Incorrect signature in '%s'", filename);
+    return false;
+  }
+
+  u32 session_offset;
+  std::memcpy(&session_offset, &mds[0x50], sizeof(session_offset));
+  if ((session_offset + 24) > mds.size())
+  {
+    Log_ErrorPrintf("Invalid session offset in '%s'", filename);
+    return false;
+  }
+
+  u16 track_count;
+  u32 track_offset;
+  std::memcpy(&track_count, &mds[session_offset + 14], sizeof(track_count));
+  std::memcpy(&track_offset, &mds[session_offset + 20], sizeof(track_offset));
+  if (track_count > 99 || track_offset >= mds.size())
+  {
+    Log_ErrorPrintf("Invalid track count/block offset %u/%u in '%s'", track_count, track_offset, filename);
+    return false;
+  }
+
+  while ((track_offset + sizeof(TrackEntry)) <= mds.size())
+  {
+    TrackEntry track;
+    std::memcpy(&track, &mds[track_offset], sizeof(track));
+    if (track.track_number < 0xA0)
+      break;
+
+    track_offset += sizeof(TrackEntry);
+  }
+
+  for (u32 track_number = 1; track_number <= track_count; track_number++)
+  {
+    if ((track_offset + sizeof(TrackEntry)) > mds.size())
+    {
+      Log_ErrorPrintf("End of file in '%s' at track %u", filename, track_number);
+      return false;
+    }
+
+    TrackEntry track;
+    std::memcpy(&track, &mds[track_offset], sizeof(track));
+    if (PackedBCDToBinary(track.track_number) != track_number)
+    {
+      Log_ErrorPrintf("Unexpected track number 0x%02X in track %u", track.track_number, track_number);
+      return false;
+    }
+    
+    const bool contains_subchannel = (track.has_subchannel_data != 0);
+    const u32 track_sector_size = (contains_subchannel ? 2448 : RAW_SECTOR_SIZE);
+    const TrackMode mode = (track.track_type == 0xA9) ? TrackMode::Audio : TrackMode::Mode2Raw;
+
+    if ((track.extra_offset + sizeof(u32) + sizeof(u32)) > mds.size())
+    {
+      Log_ErrorPrintf("Invalid extra offset %u in track %u", track.extra_offset, track_number);
+      return false;
+    }
+
+    u32 track_start_lba = Position::FromBCD(track.start_m, track.start_s, track.start_f).ToLBA();
+    u32 track_file_offset = track.track_offset_in_mdf;
+
+    u32 track_pregap;
+    u32 track_length;
+    std::memcpy(&track_pregap, &mds[track.extra_offset], sizeof(track_pregap));
+    std::memcpy(&track_length, &mds[track.extra_offset + sizeof(u32)], sizeof(track_length));
+
+    // precompute subchannel q flags for the whole track
+    // todo: pull from mds?
+    SubChannelQ::Control control{};
+    control.data = mode != TrackMode::Audio;
+
+    // create the index for the pregap
+    if (track_pregap > 0)
+    {
+      if (track_pregap > track_start_lba)
+      {
+        Log_ErrorPrintf("Track pregap %u is too large for start lba %u", track_pregap, track_start_lba);
+        return false;
+      }
+
+      Index pregap_index = {};
+      pregap_index.start_lba_on_disc = track_start_lba - track_pregap;
+      pregap_index.start_lba_in_track = static_cast<LBA>(-static_cast<s32>(track_pregap));
+      pregap_index.length = track_pregap;
+      pregap_index.track_number = track_number;
+      pregap_index.index_number = 0;
+      pregap_index.mode = mode;
+      pregap_index.control.bits = control.bits;
+      pregap_index.is_pregap = true;
+
+      const bool pregap_in_file = (track_number > 1);
+      if (pregap_in_file)
+      {
+        pregap_index.file_index = 0;
+        pregap_index.file_offset = track_file_offset;
+        pregap_index.file_sector_size = track_sector_size;
+        track_file_offset += track_pregap * track_sector_size;
+      }
+
+      m_indices.push_back(pregap_index);
+    }
+
+    // add the track itself
+    m_tracks.push_back(Track{static_cast<u32>(track_number), track_start_lba, static_cast<u32>(m_indices.size()),
+                             static_cast<u32>(track_length), mode, control});
+
+    // how many indices in this track?
+    Index last_index;
+    last_index.start_lba_on_disc = track_start_lba;
+    last_index.start_lba_in_track = 0;
+    last_index.track_number = track_number;
+    last_index.index_number = 1;
+    last_index.file_index = 0;
+    last_index.file_sector_size = track_sector_size;
+    last_index.file_offset = track_file_offset;
+    last_index.mode = mode;
+    last_index.control.bits = control.bits;
+    last_index.is_pregap = false;
+    last_index.length = track_length;
+    m_indices.push_back(last_index);
+  }
+
+  if (m_tracks.empty())
+  {
+    Log_ErrorPrintf("File '%s' contains no tracks", filename);
+    return false;
+  }
+
+  m_lba_count = m_tracks.back().start_lba + m_tracks.back().length;
+  AddLeadOutIndex();
+
+  m_sbi.LoadSBI(FileSystem::ReplaceExtension(filename, "sbi").c_str());
+
+  return Seek(1, Position{0, 0, 0});
+}
+
+bool CDImageMds::ReadSubChannelQ(SubChannelQ* subq)
+{
+  if (m_sbi.GetReplacementSubChannelQ(m_position_on_disc, subq))
+    return true;
+
+  return CDImage::ReadSubChannelQ(subq);
+}
+
+bool CDImageMds::HasNonStandardSubchannel() const
+{
+  return (m_sbi.GetReplacementSectorCount() > 0);
+}
+
+bool CDImageMds::ReadSectorFromIndex(void* buffer, const Index& index, LBA lba_in_index)
+{
+  const u64 file_position = index.file_offset + (static_cast<u64>(lba_in_index) * index.file_sector_size);
+  if (m_mdf_file_position != file_position)
+  {
+    if (std::fseek(m_mdf_file, static_cast<long>(file_position), SEEK_SET) != 0)
+      return false;
+
+    m_mdf_file_position = file_position;
+  }
+
+  // we don't want the subchannel data
+  const u32 read_size = RAW_SECTOR_SIZE;
+  if (std::fread(buffer, read_size, 1, m_mdf_file) != 1)
+  {
+    std::fseek(m_mdf_file, static_cast<long>(m_mdf_file_position), SEEK_SET);
+    return false;
+  }
+
+  m_mdf_file_position += read_size;
+  return true;
+}
+
+std::unique_ptr<CDImage> CDImage::OpenMdsImage(const char* filename)
+{
+  std::unique_ptr<CDImageMds> image = std::make_unique<CDImageMds>();
+  if (!image->OpenAndParse(filename))
+    return {};
+
+  return image;
+}

src/common/common.vcxproj

@@ -132,6 +132,7 @@
     <ClCompile Include="cd_image_cue.cpp" />
     <ClCompile Include="cd_image_ecm.cpp" />
     <ClCompile Include="cd_image_hasher.cpp" />
+    <ClCompile Include="cd_image_mds.cpp" />
     <ClCompile Include="cd_image_memory.cpp" />
     <ClCompile Include="crash_handler.cpp" />
     <ClCompile Include="d3d11\shader_cache.cpp" />

src/common/common.vcxproj.filters

@@ -211,6 +211,7 @@
     </ClCompile>
     <ClCompile Include="crash_handler.cpp" />
     <ClCompile Include="cd_image_ecm.cpp" />
+    <ClCompile Include="cd_image_mds.cpp" />
   </ItemGroup>
   <ItemGroup>
     <Natvis Include="bitfield.natvis" />

src/core/system.cpp

@@ -296,10 +296,10 @@ bool IsM3UFileName(const char* path)
 
 bool IsLoadableFilename(const char* path)
 {
-  static constexpr auto extensions = make_array(".bin", ".cue", ".img", ".iso", ".chd", ".ecm", // discs
-                                                ".exe", ".psexe",                               // exes
-                                                ".psf", ".minipsf",                             // psf
-                                                ".m3u"                                          // playlists
+  static constexpr auto extensions = make_array(".bin", ".cue", ".img", ".iso", ".chd", ".ecm", ".mds", // discs
+                                                ".exe", ".psexe",                                       // exes
+                                                ".psf", ".minipsf",                                     // psf
+                                                ".m3u"                                                  // playlists
   );
   const char* extension = std::strrchr(path, '.');
   if (!extension)

src/duckstation-qt/mainwindow.cpp

@@ -33,9 +33,10 @@
 
 static constexpr char DISC_IMAGE_FILTER[] = QT_TRANSLATE_NOOP(
   "MainWindow",
-  "All File Types (*.bin *.img *.iso *.cue *.chd *.ecm *.exe *.psexe *.psf *.minipsf *.m3u);;Single-Track Raw Images "
-  "(*.bin *.img *.iso);;Cue Sheets (*.cue);;MAME CHD Images (*.chd);;Error Code Modeler Images (*.ecm);;PlayStation "
-  "Executables (*.exe *.psexe);;Portable Sound Format Files (*.psf *.minipsf);;Playlists (*.m3u)");
+  "All File Types (*.bin *.img *.iso *.cue *.chd *.ecm *.mds *.exe *.psexe *.psf *.minipsf *.m3u);;Single-Track Raw "
+  "Images (*.bin *.img *.iso);;Cue Sheets (*.cue);;MAME CHD Images (*.chd);;Error Code Modeler Images (*.ecm);;Media "
+  "Descriptor Sidecar Images (*.mds);;PlayStation Executables (*.exe *.psexe);;Portable Sound Format Files (*.psf "
+  "*.minipsf);;Playlists (*.m3u)");
 
 ALWAYS_INLINE static QString getWindowTitle()
 {

src/frontend-common/fullscreen_ui.cpp

@@ -513,7 +513,8 @@ bool InvalidateCachedTexture(const std::string& path)
 
 static ImGuiFullscreen::FileSelectorFilters GetDiscImageFilters()
 {
-  return {"*.bin", "*.cue", "*.iso", "*.img", "*.chd", "*.ecm", "*.psexe", "*.exe", "*.psf", "*.minipsf", "*.m3u"};
+  return {"*.bin", "*.cue",   "*.iso", "*.img", "*.chd",     "*.ecm",
+          "*.mds", "*.psexe", "*.exe", "*.psf", "*.minipsf", "*.m3u"};
 }
 
 static void DoStartPath(const std::string& path, bool allow_resume)