From Jeffrey Kinross, "I ran into an issue with case sensitivity on OS X and the OSXAVFoundation code.
In CMakeList.txt there is a case sensitivity issue which a fix was posted by Robert Osfield in the users forum.

I also had to rename the files OSXAvFoundationCoreVideoTexture.h and OSXAvFoundationCoreVideoTexture.cpp to OSXAVFoundationCoreVideoTexture.h and OSXAVFoundationCoreVideoTexture.cpp

Finally in OSXAvFoundationCoreVideoTexture.cpp the include OSXAVFoundationVideo.H was updated to OSXAVFoundationVideo.h"