CDROM: Synthesize lead-out area and stop reading when reached

src/common/cd_image.cpp

@@ -168,8 +168,16 @@ bool CDImage::ReadRawSector(void* buffer)
   }
   else
   {
-    // This in an implicit pregap. Return silence.
-    std::fill(static_cast<u8*>(buffer), static_cast<u8*>(buffer) + RAW_SECTOR_SIZE, u8(0));
+    if (m_current_index->track_number == LEAD_OUT_TRACK_NUMBER)
+    {
+      // Lead-out area.
+      std::fill(static_cast<u8*>(buffer), static_cast<u8*>(buffer) + RAW_SECTOR_SIZE, u8(0xAA));
+    }
+    else
+    {
+      // This in an implicit pregap. Return silence.
+      std::fill(static_cast<u8*>(buffer), static_cast<u8*>(buffer) + RAW_SECTOR_SIZE, u8(0));
+    }
   }
 
   m_position_on_disc++;
@@ -246,6 +254,16 @@ void CDImage::GenerateSubChannelQ(SubChannelQ* subq, const Index* index, u32 ind
   subq->crc = SubChannelQ::ComputeCRC(subq->data);
 }
 
+void CDImage::AddLeadOutIndex()
+{
+  Index index = {};
+  index.start_lba_on_disc = m_lba_count;
+  index.length = LEAD_OUT_SECTOR_COUNT;
+  index.track_number = 0xAA;
+  index.index_number = 0;
+  m_indices.push_back(index);
+}
+
 u16 CDImage::SubChannelQ::ComputeCRC(const u8* data)
 {
   static constexpr std::array<u16, 256> crc16_table = {

src/common/cd_image.h

@@ -23,7 +23,13 @@ public:
     FRAMES_PER_SECOND = 75, // "sectors", or "timecode frames" (not "channel frames")
     SECONDS_PER_MINUTE = 60,
     FRAMES_PER_MINUTE = FRAMES_PER_SECOND * SECONDS_PER_MINUTE,
-    SUBCHANNEL_BYTES_PER_FRAME = 12
+    SUBCHANNEL_BYTES_PER_FRAME = 12,
+    LEAD_OUT_SECTOR_COUNT = 6750
+  };
+
+  enum : u8
+  {
+    LEAD_OUT_TRACK_NUMBER = 0xAA
   };
 
   enum class ReadMode : u32
@@ -235,6 +241,9 @@ protected:
   /// Generates sub-channel Q from the given index and index-offset.
   void GenerateSubChannelQ(SubChannelQ* subq, const Index* index, u32 index_offset);
 
+  /// Synthesis of lead-out data.
+  void AddLeadOutIndex();
+
   std::string m_filename;
   u32 m_lba_count = 0;
 

src/common/cd_image_bin.cpp

@@ -99,6 +99,8 @@ bool CDImageBin::Open(const char* filename)
   m_tracks.push_back(
     Track{static_cast<u32>(1), data_index.start_lba_on_disc, static_cast<u32>(0), m_lba_count, mode, control});
 
+  AddLeadOutIndex();
+
   m_sbi.LoadSBI(ReplaceExtension(filename, "sbi").c_str());
 
   return Seek(1, Position{0, 0, 0});

src/common/cd_image_chd.cpp

@@ -222,6 +222,7 @@ bool CDImageCHD::Open(const char* filename)
   }
 
   m_lba_count = disc_lba;
+  AddLeadOutIndex();
 
   m_sbi.LoadSBI(FileSystem::ReplaceExtension(filename, "sbi").c_str());
 

src/common/cd_image_cue.cpp

@@ -210,6 +210,7 @@ bool CDImageCueSheet::OpenAndParse(const char* filename)
   }
 
   m_lba_count = disc_lba;
+  AddLeadOutIndex();
 
   m_sbi.LoadSBI(FileSystem::ReplaceExtension(filename, "sbi").c_str());
 

src/core/cdrom.cpp

@@ -1448,6 +1448,17 @@ void CDROM::DoTOCRead()
   SetAsyncInterrupt(Interrupt::Complete);
 }
 
+void CDROM::StopReadingWithDataEnd()
+{
+  ClearAsyncInterrupt();
+  m_async_response_fifo.Push(m_secondary_status.bits);
+  SetAsyncInterrupt(Interrupt::DataEnd);
+
+  m_secondary_status.ClearActiveBits();
+  m_drive_state = DriveState::Idle;
+  m_drive_event->Deactivate();
+}
+
 void CDROM::DoSectorRead()
 {
   if (!m_reader.WaitForReadToComplete())
@@ -1456,6 +1467,13 @@ void CDROM::DoSectorRead()
   // TODO: Error handling
   // TODO: Check SubQ checksum.
   const CDImage::SubChannelQ& subq = m_reader.GetSectorSubQ();
+  if (subq.track_number_bcd == CDImage::LEAD_OUT_TRACK_NUMBER)
+  {
+    Log_DevPrintf("Read reached lead-out area of disc at LBA %u, pausing", m_reader.GetLastReadSector());
+    StopReadingWithDataEnd();
+    return;
+  }
+
   const bool is_data_sector = subq.control.data;
   if (!is_data_sector)
   {
@@ -1471,13 +1489,7 @@ void CDROM::DoSectorRead()
       Log_DevPrintf("Auto pause at the end of track %u (LBA %u)", m_play_track_number_bcd,
                     m_reader.GetLastReadSector());
 
-      ClearAsyncInterrupt();
-      m_async_response_fifo.Push(m_secondary_status.bits);
-      SetAsyncInterrupt(Interrupt::DataEnd);
-
-      m_secondary_status.ClearActiveBits();
-      m_drive_state = DriveState::Idle;
-      m_drive_event->Deactivate();
+      StopReadingWithDataEnd();
       return;
     }
   }

src/core/cdrom.h

@@ -234,6 +234,7 @@ private:
   void ProcessDataSector(const u8* raw_sector, const CDImage::SubChannelQ& subq);
   void ProcessXAADPCMSector(const u8* raw_sector, const CDImage::SubChannelQ& subq);
   void ProcessCDDASector(const u8* raw_sector, const CDImage::SubChannelQ& subq);
+  void StopReadingWithDataEnd();
   void BeginSeeking(bool logical, bool read_after_seek, bool play_after_seek);
   void ResetCurrentXAFile();
   void LoadDataFIFO();