Builds cinelerra-cv-2.2.1-20141224git70b8c14.tar.bz2 with libmpeg3-1.8-7
from rpmfusion and rpmfusion_nonfree buildroot.

Example:
rpmbuild -bs cinelerra-cv.spec  --define "_sourcedir ." --define '_srcrpmdir .'
mock -r fedora-21-x86_64-rpmfusion_nonfree --no-clean --rebuild ./cinelerra-cv-2.2.1-0.9.20141224git70b8c14.fc20.src.rpm