/** The callback function that modules implement to construct a service.
*/
-typedef void *( *mlt_register_callback )( mlt_profile, mlt_service_type, const char * /* service name */, void * /* arg */ );
+typedef void *( *mlt_register_callback )( mlt_profile, mlt_service_type, const char * /* service name */, const void * /* arg */ );
/** The callback function that modules implement to supply metadata as a properties list.
*/
extern mlt_repository mlt_repository_init( const char *directory );
extern void mlt_repository_register( mlt_repository self, mlt_service_type service_type, const char *service, mlt_register_callback );
-extern void *mlt_repository_create( mlt_repository self, mlt_profile profile, mlt_service_type type, const char *service, void *arg );
+extern void *mlt_repository_create( mlt_repository self, mlt_profile profile, mlt_service_type type, const char *service, const void *arg );
extern void mlt_repository_close( mlt_repository self );
extern mlt_properties mlt_repository_consumers( mlt_repository self );
extern mlt_properties mlt_repository_filters( mlt_repository self );