diff --git a/CMakeLists.txt b/CMakeLists.txt
index cdfebd05..5c4e11d1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -80,6 +80,7 @@ add_library(lego1 SHARED
   LEGO1/legoroi.cpp
   LEGO1/legosoundmanager.cpp
   LEGO1/legostate.cpp
+  LEGO1/legostream.cpp
   LEGO1/legotexturepresenter.cpp
   LEGO1/legoutil.cpp
   LEGO1/legovideomanager.cpp
diff --git a/LEGO1/legostream.cpp b/LEGO1/legostream.cpp
new file mode 100644
index 00000000..1fd2bf11
--- /dev/null
+++ b/LEGO1/legostream.cpp
@@ -0,0 +1,149 @@
+
+#include "legostream.h"
+
+#include <cstdio>
+#include <string>
+
+// Very likely but not certain sizes.
+// The classes are only used on the stack in functions we have not 100% matched
+// yet, we can confirm the size once we have.
+DECOMP_SIZE_ASSERT(LegoStream, 0x8);
+DECOMP_SIZE_ASSERT(LegoFileStream, 0xC);
+DECOMP_SIZE_ASSERT(LegoMemoryStream, 0x10);
+
+// OFFSET: LEGO1 0x10045ae0
+MxBool LegoStream::IsWriteMode()
+{
+  return m_mode == LEGOSTREAM_MODE_WRITE;
+}
+
+// OFFSET: LEGO1 0x10045af0
+MxBool LegoStream::IsReadMode()
+{
+  return m_mode == LEGOSTREAM_MODE_READ;
+}
+
+// OFFSET: LEGO1 0x100991c0
+LegoFileStream::LegoFileStream()
+  : LegoStream()
+{
+  m_hFile = NULL;
+}
+
+// OFFSET: LEGO1 0x10099250
+LegoFileStream::~LegoFileStream()
+{
+  if (m_hFile != NULL)
+    fclose(m_hFile);
+}
+
+// OFFSET: LEGO1 0x100992c0
+MxResult LegoFileStream::Read(char* p_buffer, MxU32 p_size)
+{
+  if (m_hFile == NULL)
+    return FAILURE;
+
+  return (fread(p_buffer, 1, p_size, m_hFile) == p_size) ? SUCCESS : FAILURE;
+}
+
+// OFFSET: LEGO1 0x10099300
+MxResult LegoFileStream::Write(char* p_buffer, MxU32 p_size)
+{
+  if (m_hFile == NULL)
+    return FAILURE;
+
+  return (fwrite(p_buffer, 1, p_size, m_hFile) == p_size) ? SUCCESS : FAILURE;
+}
+
+// OFFSET: LEGO1 0x10099340
+MxResult LegoFileStream::Tell(MxU32* p_offset)
+{
+  if (m_hFile == NULL)
+    return FAILURE;
+
+  int got = ftell(m_hFile);
+  if (got == -1)
+    return FAILURE;
+
+  *p_offset = got;
+  return SUCCESS;
+}
+
+// OFFSET: LEGO1 0x10099370
+MxResult LegoFileStream::Seek(MxU32 p_offset)
+{
+  if (m_hFile == NULL)
+    return FAILURE;
+
+  return (fseek(m_hFile, p_offset, 0) == 0) ? SUCCESS : FAILURE;
+}
+
+// OFFSET: LEGO1 0x100993a0
+MxResult LegoFileStream::Open(const char* p_filename, OpenFlags p_mode)
+{
+  char modeString[4];
+
+  if (m_hFile != NULL)
+    fclose(m_hFile);
+  
+  modeString[0] = '\0';
+  if (p_mode & ReadBit)
+  {
+    m_mode = LEGOSTREAM_MODE_READ;
+    strcat(modeString, "r");
+  }
+
+  if (p_mode & WriteBit)
+  {
+    if (m_mode != LEGOSTREAM_MODE_READ)
+      m_mode = LEGOSTREAM_MODE_WRITE;
+    strcat(modeString, "w");
+  }
+
+  if ((p_mode & 4) != 0)
+    strcat(modeString, "b");
+  else
+    strcat(modeString, "t");
+
+  return (m_hFile = fopen(p_filename, modeString)) ? SUCCESS : FAILURE;
+}
+
+// OFFSET: LEGO1 0x10099080
+LegoMemoryStream::LegoMemoryStream(char* p_buffer)
+  : LegoStream()
+{
+  m_buffer = p_buffer;
+  m_offset = 0;
+}
+
+// OFFSET: LEGO1 0x10099160
+MxResult LegoMemoryStream::Read(char* p_buffer, MxU32 p_size)
+{
+  memcpy(p_buffer, m_buffer + m_offset, p_size);
+  m_offset += p_size;
+  return SUCCESS;
+}
+
+// OFFSET: LEGO1 0x10099190
+MxResult LegoMemoryStream::Write(char* p_buffer, MxU32 p_size)
+{
+  memcpy(m_buffer + m_offset, p_buffer, p_size);
+  m_offset += p_size;
+  return SUCCESS;
+}
+
+// OFFSET: LEGO1 0x100994a0
+MxResult LegoMemoryStream::Tell(MxU32* p_offset)
+{
+  *p_offset = m_offset;
+  return SUCCESS;
+}
+
+// OFFSET: LEGO1 0x100994b0
+MxResult LegoMemoryStream::Seek(MxU32 p_offset)
+{
+  m_offset = p_offset;
+  return SUCCESS;
+}
+
+
diff --git a/LEGO1/legostream.h b/LEGO1/legostream.h
new file mode 100644
index 00000000..a505cd54
--- /dev/null
+++ b/LEGO1/legostream.h
@@ -0,0 +1,73 @@
+#ifndef LEGOSTREAM_H
+#define LEGOSTREAM_H
+
+#include "decomp.h"
+#include "mxtypes.h"
+
+#include <iosfwd>
+
+#define LEGOSTREAM_MODE_READ 1
+#define LEGOSTREAM_MODE_WRITE 2
+
+// VTABLE 0x100d7d80
+class LegoStream
+{
+public:
+  LegoStream() : m_mode(0) {}
+  inline virtual ~LegoStream() {};
+
+  virtual MxResult Read(char* p_buffer, MxU32 p_size) = 0;
+  virtual MxResult Write(char* p_buffer, MxU32 p_size) = 0;
+  virtual MxResult Tell(MxU32* p_offset) = 0;
+  virtual MxResult Seek(MxU32 p_offset) = 0;
+
+  virtual MxBool IsWriteMode();
+  virtual MxBool IsReadMode();
+
+  enum OpenFlags
+  {
+    ReadBit = 1,
+    WriteBit = 2,
+    BinaryBit = 4,
+  };
+
+protected:
+  MxU8 m_mode;
+};
+
+// VTABLE 0x100db730
+class LegoFileStream : public LegoStream
+{
+public:
+  LegoFileStream();
+  virtual ~LegoFileStream();
+
+  MxResult Read(char* p_buffer, MxU32 p_size) override;
+  MxResult Write(char* p_buffer, MxU32 p_size) override;
+  MxResult Tell(MxU32* p_offset) override;
+  MxResult Seek(MxU32 p_offset) override;
+
+  MxResult Open(const char* p_filename, OpenFlags p_mode);
+
+private:
+  FILE *m_hFile;
+};
+
+// VTABLE 0x100db710
+class LegoMemoryStream : public LegoStream
+{
+public:
+  LegoMemoryStream(char* p_buffer);
+  ~LegoMemoryStream() {}
+
+  MxResult Read(char* p_buffer, MxU32 p_size) override;
+  MxResult Write(char* p_buffer, MxU32 p_size) override;
+  MxResult Tell(MxU32* p_offset) override;
+  MxResult Seek(MxU32 p_offset) override;
+
+private:
+  char *m_buffer;
+  MxU32 m_offset;
+};
+
+#endif // LEGOSTREAM_H
\ No newline at end of file