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Ogg Vorbis is a completely free and open audio compression (codec) project from the Foundation, and is part of their Ogg effort to create free and open multimedia and signal processing standards.

Like all developments of the Ogg project, Vorbis is believed by the developers to be completely free from the licensing or patent issues raised by other proprietary formats such as MP3. Outside parties have doubted the claim that Vorbis would be patent free; but have so far not produced any supporting evidence so this has been derided by some as so-called "FUD": disinformation spread by large companies with a vested interest.

Compared to other audio formats Ogg Vorbis is relatively new, having been refined by developers until a stable version 1.0 of the codec was released on July 19, 2002.

Table of contents
1 Popularity Growth
2 Technical Details
3 Hardware and Software Support
4 See also
5 External links

Popularity Growth

The Ogg Vorbis format has proved popular among open source communities, and they argue that due to its higher fidelity, and completely free nature, it is a natural replacement for the entrenched MP3 format. However, MP3 has a popular history dating back to the mid-1990s and is still the primary lossy audio format. It may be some time before one sees more Ogg format files than MP3 files. In the commercial sector, Ogg Vorbis has already replaced MP3 as the de facto standard audio codec, with many newer video game titles employing Ogg Vorbis as opposed to MP3. The lack of widely available hardware players is hindering its growth at the moment. See further down for compatible hardware.

Technical Details

Given 44.1 kHz (standard CD audio sample frequency) stereo input, the current encoder will produce output from 45 to 500 kbit/s, depending upon the specified quality setting. While Vorbis 1.0 is tuned for bitrates of 16-128 kbit/s/channel it is still possible to encode at arbitrary bitrates chosen by the user. Such figures are only approximate, however, as Vorbis is inherently variable bitrate (VBR). Vorbis currently produces better audio quality and smaller file sizes than other formats under comparable circumstances.

The specifications are placed in the public domain, the libraries are released under a BSD-style license, and the tools are released under the GPL (GNU General Public License).

Vorbis uses the modified discrete cosine transform (MDCT) for converting the sound data from time domain to frequency domain and back.

Hardware and Software Support

A fixed-point implementation of the Ogg Vorbis decoder, called Tremor, was released on September 2, 2002. It was released to encourage that manufacturers of hardware audio players to support the format in upcoming versions and models of their devices. Tremor is also released under a BSD-style license.



RealNetworks has announced that they will support Ogg Vorbis in their products. See Helix project for more details.

Ogg Vorbis can be played using these (and other) players:

Ogg-Vorbis DirectShow codec version to use with

It can also be played with the Windows Media Player using

Ogg-Vorbis DirectShow filter.
The BBC has recently experimented with putting out Vorbis-encoded audio streams. The technical experiments are now complete, and the BBC is considering whether to deploy the technology.

"Ogg" is not named after the witch Nanny Ogg in Terry Pratchett's Discworld books. However, "Vorbis" is named after another Discworld character, High Priest Vorbis in Small Gods.

See also

External links