diff --git a/include/utils/Functor.h b/include/utils/Functor.h
index 3955bc3..565f4a3 100644
--- a/include/utils/Functor.h
+++ b/include/utils/Functor.h
@@ -26,6 +26,7 @@
     Functor() {}
     virtual ~Functor() {}
     virtual status_t operator ()() { return true; }
+    virtual status_t operator ()(float* data, uint32_t len) { return true; }
 };
 
 }; // namespace android