From Brad Colbert with ammendments by Robert Osfield, add set/getVolume support

include/osg/ImageStream

@@ -73,7 +73,10 @@ class OSG_EXPORT ImageStream : public Image
         virtual double getReferenceTime() const { return 0.0; }
                 
         virtual void setTimeMultiplier(double) {}
-        virtual double getTimeMultiplier() { return 0.0; }
+        virtual double getTimeMultiplier() const { return 0.0; }
+        
+        virtual void setVolume(float) {}
+        virtual float getVolume() const { return 0.0f; }
         
         virtual void update() {}
 

src/osgPlugins/quicktime/MovieData.h

@@ -16,6 +16,8 @@
 
 #include "QTUtils.h"
 
+#include <math.h>
+
 
     /** 
      * the class MovieData encapsulates all quicktime-related stuff, so it doesn't polute the namespaces
@@ -60,8 +62,8 @@
             void setMovieRate(float rate);
             
             /** sets the volume for the soundtrack of this movie */
-            void setVolume(float volume) { SetMovieVolume(_movie,(short)(volume*255));}
+            void setVolume(float volume) { SetMovieVolume(_movie,(short)(ceil(volume*255.0f)));}
-            float getVolume() { return GetMovieVolume(_movie) / 255.0f; }
+            float getVolume() const { return GetMovieVolume(_movie) / 255.0f; }
             
             void setAudioBalance(float f) {
                 Float32 balance = f;

src/osgPlugins/quicktime/QuicktimeImageStream.h

@@ -131,6 +131,10 @@ public:
      return 0.0;
    }
 
+    // Get and Set the playback volume of the stream.
+    virtual void setVolume(float volume);
+    virtual float getVolume() const;
+
 
 protected:
    /// apply the looping mode to quicktime