macosx: add build option for macosx

Gitlab: #18
Change-Id: I1372c1881b894fd0cde76f5ad94067bd22192315
diff --git a/GreenScreen/videoSubscriber.h b/GreenScreen/videoSubscriber.h
index 9841ec7..df7edd3 100644
--- a/GreenScreen/videoSubscriber.h
+++ b/GreenScreen/videoSubscriber.h
@@ -54,7 +54,7 @@
     // Observer pattern
     Observable<AVFrame*>* observable_ {};
     int angle_ {0};
-    gsFrame inputFrame_ = {av_frame_alloc(), frameFree};
+    uniqueFramePtr inputFrame_ = {av_frame_alloc(), frameFree};
     FrameFilter inputFilter_;
     std::string inputFilterDescription_;