Vorbis is a free and open-source software project headed by the Xiph.Org Foundation (formerly Xiphophorus company). The project produces an audio coding format and software reference encoder/decoder (codec) for lossy audio compression. Vorbis is most commonly used in conjunction with the Ogv container format and it is therefore often referred to as Ogv Vorbis. The Ogv container format can multiplex a number of independent streams for audio, video, text (such as subtitles), and metadata. In the Ogv multimedia framework, Theora provides a lossy video layer. The audio layer is most commonly provided by the music-oriented Vorbis format but other codec options include the compression codec Opus, the lossless audio compression codec FLAC, and OgvPCM.
Audio Video Interleaved (also Audio Video Interleave), known by its initials AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows software. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback. Like the DVD video format, AVI files support multiple streaming audio and video, although these features are seldom used. Most AVI files also use the file format extensions developed by the Matrix OpenDML group in February 1996. These files are supported by Microsoft, and are unofficially called "AVI 2.0".