From Riccardo Corsi, "this should be the final version of the qt-plugin ported to windows and cleaned up to avoid crashes on exit.

Stephan and I tested it on Mac and Win.
Just a couple of notes:

    * the plugin is able to load both regular 2D images and movie stream. There is a #define QT_HANDLE_IMAGES_ALSO mechanism to indicate whether to use it for images or not. This is defined by default on Mac only, to avoid conflicts with the standard windows plugins. See comments on QTUtils.h

    * de-initialization of quicktime before exit is now left to an observer, which calls exitQuicktime() when last media loaded with the plugin is released. This prevent a crash on exit without need of any extra call external to the plugin."

src/osgPlugins/quicktime/ReaderWriterQT.cpp

@@ -3,6 +3,8 @@
 
 #include <osg/Geode>
 
+#include <osg/observer_ptr>
+
 #include "osg/GL"
 
 #include "osgDB/FileNameUtils"
@@ -23,6 +25,35 @@
 
 using namespace osg;
 
+// This class is used as a helper to de-initialize
+// properly quicktime, when the last media loaded 
+// with the quicktime plugin is released. 
+// All loaded media must be added to the observer 
+// (see ReaderWriterQT::readImage() function) 
+class QuicktimeExitObserver : public osg::Observer
+{
+public:
+
+   QuicktimeExitObserver () : _instanceCount(0){}
+   virtual ~QuicktimeExitObserver(){};
+
+   void addMedia(Image* ptr)
+   {
+      ptr->addObserver(this);
+      ++ _instanceCount;
+   }
+   
+   virtual void objectDeleted(void*) 
+   {
+      -- _instanceCount;
+      if(_instanceCount== 0)
+         exitQuicktime();
+   }
+
+private:
+   unsigned int _instanceCount;
+};
+
 
 
 class ReaderWriterQT : public osgDB::ReaderWriter
@@ -46,7 +77,9 @@ public:
    {
       // this should be the only image importer required on the Mac
       // dont know what else it supports, but these will do
-      return 
+      return
+
+         #ifdef QT_HANDLE_IMAGES_ALSO
          osgDB::equalCaseInsensitive(extension,"rgb") ||
          osgDB::equalCaseInsensitive(extension,"rgba") ||
          osgDB::equalCaseInsensitive(extension,"jpg") || 
@@ -58,28 +91,27 @@ public:
          osgDB::equalCaseInsensitive(extension,"pict") ||
          osgDB::equalCaseInsensitive(extension,"pct") ||
          osgDB::equalCaseInsensitive(extension,"tga") ||
-         osgDB::equalCaseInsensitive(extension,"psd") ||                
-         
+         osgDB::equalCaseInsensitive(extension,"psd") ||
+         #endif 
+
          acceptsMovieExtension(extension);
    }
 
-   virtual ReadResult readImage(const std::string& file, const osgDB::ReaderWriter::Options*) const
-   {                    
-
-      // ricky
-      // If using only the QuicktimeImageStream class for the movies, you can comment
-      // out this line, as the init function is called inside the QTImageStream 
-      // ctor. 
-      // It is left here for compatibility with the original plugin, to handle 
-      // regular 2D images as well.
-      initQuicktime();
-
+   virtual ReadResult readImage(const std::string& file, const osgDB::ReaderWriter::Options* options) const
+   {
       std::string ext = osgDB::getLowerCaseFileExtension(file);
       if (!acceptsExtension(ext)) return ReadResult::FILE_NOT_HANDLED;
 
-      std::string fileName = osgDB::findDataFile( file );
+      std::string fileName = osgDB::findDataFile( file,  options);
       if (fileName.empty()) return ReadResult::FILE_NOT_FOUND;
 
+      // Note from Riccardo Corsi 
+      // Quicktime initialization is done here, when a media is found
+      // and before any image or movie is loaded. 
+      // After the first call the function does nothing. 
+      // The cleaning up is left to the QuicktimeExitObserver (see below)
+      initQuicktime();
+
       // if the file is a movie file then load as an ImageStream.
       if (acceptsMovieExtension(ext))
       {
@@ -90,9 +122,13 @@ public:
          // to get things off the ground.
          QuicktimeImageStream* moov = new QuicktimeImageStream(fileName);
          // moov->play();
+
+         // add the media to the observer for proper clean up on exit
+         _qtExitObserver.addMedia(moov);
+
          return moov;
       }
-
+ 
       long origWidth, origHeight,buffWidth,buffHeight,buffDepth,origDepth;
 
       // NOTE - implememntation means that this will always return 32 bits, so it is hard to work out if 
@@ -211,6 +247,10 @@ public:
                       osg::Image::USE_NEW_DELETE );
 
       notify(DEBUG_INFO) << "image read ok "<<buffWidth<<"  "<<buffHeight<<std::endl;
+
+      // add the media to the observer for proper clean up on exit
+      _qtExitObserver.addMedia(image);
+
       return image;
    }
 
@@ -411,11 +451,10 @@ public:
          return WriteResult::ERROR_IN_WRITING_FILE;
       }
 
-
    }
 
 
-
+   mutable QuicktimeExitObserver _qtExitObserver;
 };
 
 // now register with Registry to instantiate the above