fixed playback/export flickering and hanging

main.cpp

@@ -9,7 +9,7 @@ extern "C" {
 int main(int argc, char *argv[]) {
 	// init ffmpeg subsystem
 	av_register_all();
-	avfilter_register_all();
+	avfilter_register_all();	
 
     QApplication a(argc, argv);
 	MainWindow w;