Ogg Vorbis is a fully open, non-proprietary, patent-and-royalty-free, general-purpose compressed audio format for mid to high quality )8kHz-48.0kHz, 16+ bit, polyphonic: audio and music at fixed and variable bitrates from 16 to 128 kbps/channel. This places Vorbis in the same competitive class as audio representations such as MPEG-4 )AAC:, and similar to, but higher performance than MPEG-1/2 audio layer 3, MPEG-4 audio )TwinVQ:, WMA and PAC.Подробнее здесь http{//www.xiph.org/ogg/vorbis/