NOSSDAV 2012, the 22nd SIGMM Workshop on Network and Operating Systems Support for Digital Audio and Video, will be held in Toronto, Canada, on June 7-8 2012. As in previous years, the workshop will continue to focus on both established and emerging research topics, high-risk high-return ideas and proposals, and future research directions in multimedia networking and systems, in a single-track format that encourages active participation and discussions among academic and industry researchers and practitioners.