However, a patent license is required for all manufacturers or developers of AAC codecs. For this reason, free and open source software implementations such as FFmpeg and FAAC may be distributed in source form only, in order to avoid patent infringement. The AAC patent holders include Bell Labs, Dolby, Fraunhofer, LG Electronics, NEC, NTT Docomo, Panasonic, Sony Corporation,[1] ETRI, JVC Kenwood, Philips, Microsoft, and NTT.---viz tamtéž ...