Vorbis
Vorbis is a completely open and free audio compression (codec) project from the Xiph.org Foundation. It is frequently used in conjunction with the Ogg container and is then called Ogg Vorbis.Vorbis was started following a September 1998 letter from Fraunhofer Gesellschaft announcing plans to charge licensing fees for the MP3 format. Soon after founder Christopher Montgomery began work on the project, he was assisted by a growing collection other developers. They continued refining the code until a stable version 1.0 of the codec was released on July 19, 2002.
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2 Technical details 3 Licensing 4 Hardware and software Support 5 See also 6 External links |
The Ogg Vorbis format has proved popular among open source communities; 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 as of 2003 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, Vorbis has already had success with many newer video game titles employing Vorbis as opposed to MP3. The lack of widely available hardware players is hindering its growth as of November 2003; see the compatible hardware below.
Given 44.1 kHz (standard CD audio sample frequency) stereo input, the current encoder as of July 2003 will produce output from 45 to 500 kbit/s depending on the specified quality setting. Though Vorbis 1.0 is tuned for bitrates of 16-128 kbit/s/channel it is still possible to encode arbitrary bitrates chosen by the user. Such figures are only approximate, however, as inherently Vorbis is variable-bitrate (VBR).
Vorbis uses modified discrete cosine transform (MDCT) for converting sound data from the time domain to the frequency domain and back.
Vorbis's specifications are in the public domain, its libraries are released under a BSD-style license, and its tools are released under the GPL (GNU General Public License).
Like all developments of the Xiph.org Foundation project, the developers believe Vorbis is completely free from the licensing or patent issues raised by other proprietary formats such as MP3. Although Xiph claims to have conducted a limited patent search that supports its claims, outside parties have expressed doubt that Vorbis is free of patented technology. Xiph says that it was issued a legal opinion privately subject to attorney/client privilege, and has not released an official statement on the patent status of Vorbis. No conclusive evidence has been presented that Vorbis is or is not patent-free as of 2004. Vorbis proponents have derided the uncertainty concerning the patent status as "FUD" disinformation spread by large companies with a vested interest.
A fixed-point implementation of the Vorbis decoder Tremor was released (also under a BSD-style license) on September 2, 2002 to encourage hardware audio player manufacturers to support the format in upcoming versions and models of their devices.
RealNetworks announced (as of when or update?) that they will support Ogg Vorbis in their products. See Helix project for more details.
Ogg Vorbis currently can be played using these (and other) players:
"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.
Popularity growth
Technical details
Licensing
Hardware and software Support
Hardware
Software
It can also be played with Microsoft's Windows Media Player using an
Ogg Vorbis DirectShow filter available at:
There is a QuickTime component available at this Sourceforge project.
BBC has recently experimented with putting out Vorbis-encoded audio streams. The technical experiments are now complete, and BBC is considering whether to deploy the technology.See also
External links