o Added a Clone() method to InterchangeObject and derivatives

   that allows making a descriptor copy that is not owned by
   any other strucure. The caller must arrange to delete the
   object pointer returned.

 o While implementing the above it became obvious that the
   reference-to-a-pointer-to-the-dictionary idiom that is used
   throughout the lower levels of the MXF library was the
   cause of much more grief than it was originally designed to
   prevent. This was made even more obvious when I replaced all
   of it with simple pointers, which revealed several shadow
   instances of m_Dict that were only reliable while the object
   that held them was valid.

1 files changed, 6 insertions, 6 deletions

diff --git a/src/AS_DCP_PCM.cpp b/src/AS_DCP_PCM.cpp
index 6241d15..01b02ba 100755
--- a/src/AS_DCP_PCM.cpp
+++ b/src/AS_DCP_PCM.cpp
@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2004-2016, John Hurst
+Copyright (c) 2004-2021, John Hurst
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -250,7 +250,7 @@ class ASDCP::PCM::MXFReader::h__Reader : public ASDCP::h__ASDCPReader
 public:
   AudioDescriptor m_ADesc;
 
-  h__Reader(const Dictionary& d) : ASDCP::h__ASDCPReader(d) {}
+  h__Reader(const Dictionary *d) : ASDCP::h__ASDCPReader(d) {}
   virtual ~h__Reader() {}
   Result_t    OpenRead(const std::string&);
   Result_t    ReadFrame(ui32_t, FrameBuffer&, AESDecContext*, HMACContext*);
@@ -368,7 +368,7 @@ ASDCP::PCM::FrameBuffer::Dump(FILE* stream, ui32_t dump_len) const
 
 ASDCP::PCM::MXFReader::MXFReader()
 {
-  m_Reader = new h__Reader(DefaultCompositeDict());
+  m_Reader = new h__Reader(&DefaultCompositeDict());
 }
 
 
@@ -523,7 +523,7 @@ public:
   AudioDescriptor m_ADesc;
   byte_t          m_EssenceUL[SMPTE_UL_LENGTH];
   
-  h__Writer(const Dictionary& d) : ASDCP::h__ASDCPWriter(d) {
+  h__Writer(const Dictionary *d) : ASDCP::h__ASDCPWriter(d) {
     memset(m_EssenceUL, 0, SMPTE_UL_LENGTH);
   }
 
@@ -718,9 +718,9 @@ ASDCP::PCM::MXFWriter::OpenWrite(const std::string& filename, const WriterInfo&
 				 const AudioDescriptor& ADesc, ui32_t HeaderSize)
 {
   if ( Info.LabelSetType == LS_MXF_SMPTE )
-    m_Writer = new h__Writer(DefaultSMPTEDict());
+    m_Writer = new h__Writer(&DefaultSMPTEDict());
   else
-    m_Writer = new h__Writer(DefaultInteropDict());
+    m_Writer = new h__Writer(&DefaultInteropDict());
 
   m_Writer->m_Info = Info;