added additional packages needed to build QGC

README.md

@@ -41,7 +41,7 @@ You **need to install Qt as described below** instead of using pre-built package
     * Windows: Make sure to install VS 2015 32 bit package.
 
 ###### Install additional packages:
-* Ubuntu: sudo apt-get install speech-dispatcher libudev-dev libsdl2-dev
+* Ubuntu: sudo apt-get install speech-dispatcher libudev-dev libsdl2-dev libgstreamer1.0-0 gstreamer1.0-plugins-base libgstreamer-plugins-base1.0-dev gstreamer1.0*
 * Fedora: sudo dnf install speech-dispatcher SDL2-devel SDL2 systemd-devel
 * Arch Linux: pacman -Sy speech-dispatcher
 * Windows: [USB Driver](http://www.pixhawk.org/firmware/downloads) to connect to Pixhawk/PX4Flow/3DR Radio