Vorbis

Vorbis is a free, open-source lossy audio compression format developed by the Xiph.Org Foundation as part of the Ogg project. It uses a perceptual codec with a transform-based encoder and entropy coding to achieve efficient compression. The encoded audio data is carried in the Ogg container, commonly referred to as Ogg Vorbis, with files usually bearing the .ogg extension.

Technical characteristics: Vorbis supports stereo and multichannel audio, variable bitrate encoding, and quality-based encoding scales (traditionally described by a 0–10 quality setting). It employs psychoacoustic modeling and adaptive bit allocation to balance fidelity and data rate. Reference implementations include libvorbis for decoding and encoding and libogg for the container.

Licensing and ecosystem: Vorbis is released under a permissive free/open-source license and is designed to be patent-unencumbered. It has become widely supported by open-source multimedia software and many hardware players, particularly in Linux distributions and cross-platform media frameworks. It coexists with the Ogg container format and is often used in streaming and storage of audio data.

History and influence: Vorbis emerged in the early 2000s as part of Xiph.org's effort to provide a royalty-free alternative to proprietary codecs. It has influenced subsequent open formats and served as a basis for later codecs in the Xiph ecosystem, though it has been largely eclipsed in newer applications by Opus for many streaming and communication uses.