For Ubuntu:
sudo apt-get install libqt5multimedia5-plugins qtmultimedia5-dev qttools5-dev qttools5-dev-tools libqt5opengl5-dev qtbase5-dev libusb-1.0 librtlsdr-dev
mkdir out && cd out && cmake ../ && make
"librtlsdr-dev" is in the "universe" repo. (utopic 14.10 amd64.)