Theora is a
free lossy
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data si ...
video compression format
A video coding format (or sometimes video compression format) is a content representation format for storage or transmission of digital video content (such as in a data file or bitstream). It typically uses a standardized video compression algo ...
. It is developed by the
Xiph.Org Foundation and distributed without licensing fees alongside their other free and open media projects, including the
Vorbis
Vorbis is a free and open-source software project headed by the Xiph.Org Foundation. The project produces an audio coding format and software reference encoder/decoder ( codec) for lossy audio compression. Vorbis is most commonly used in con ...
audio format and the
Ogg container.
The libtheora
video codec
A video codec is software or hardware that compresses and decompresses digital video. In the context of video compression, '' codec'' is a portmanteau of ''encoder'' and ''decoder'', while a device that only compresses is typically called an ...
is the
reference implementation
In the software development process, a reference implementation (or, less frequently, sample implementation or model implementation) is a program that implements all requirements from a corresponding specification. The reference implementation o ...
of the Theora video compression format being developed by the Xiph.Org Foundation.
Theora is derived from the formerly