Vorbis metadata, called Vorbis comments, supports metadata tags similar to those implemented in the ID3 standard for MP3. Vorbis streams can also be encapsulated in an RTP payload format. It is also used in WebM, a container format based on a subset of Matroska. Vorbis streams can be encapsulated in other media container formats besides Ogg. The sound of compression artifacts at low bitrates can be perhaps described as reverberations in an amphitheater or a room. The noise-floor approach gives Vorbis its characteristic analog noise-like failure mode when the bitrate is too low to encode the audio without perceptible loss. The decompression algorithm reverses these stages. The resulting frequency-domain data is broken into noise floor and residue components, and then quantized and entropy coded using a codebook-based vector quantization algorithm. Vorbis uses the modified discrete cosine transform for converting sound data from the time domain to the frequency domain. Vorbis I is a forward-adaptive monolithic transform codec based on the modified discrete cosine transform (MDCT). The new libvorbis v1.2 usually compresses better than these values (effective bitrate may vary). Technical details Vorbis nominal bitrate at quality levels for 44.1 kHz stereo input. Also, the French music site Qobuz offers its customers the possibility to download their purchased songs in Vorbis format, as does the American music site Bandcamp. The Spotify audio streaming service has used Vorbis in a basket of codecs for its audio streams, but now has also been using AAC profiles. Others include Jamendo and Mindawn, as well as several national radio stations like JazzRadio, Absolute Radio, NPR, Radio New Zealand and Deutschlandradio. A number of websites, including Wikipedia, use it. Popular software players support Vorbis playback either natively or through an external plugin. Many video games store in-game audio as Vorbis, including Amnesia: The Dark Descent, Grand Theft Auto: San Andreas, Halo: Combat Evolved, Minecraft, and World of Warcraft, among others. Vorbis has different uses for consumer products. They argue that its higher fidelity and completely free nature, unencumbered by patents, make it a well-suited replacement for patented and restricted formats. The Vorbis format has proven popular among supporters of free software. Because Vorbis does not have financial support from large organisations, support for the format is not as widespread, though programs such as Audacity can convert to more popular formats, and support in games has gradually improved. Though Vorbis is technically superior (addressing many of the limitations inherent to the MP3 design), MP3 has a far higher public profile. Vorbis faces competition from other audio formats, such as MP3. The Ogg format, however, is not named after Nanny Ogg, another Discworld character the name is in fact derived from ogging, jargon that arose in the computer game Netrek. Vorbis is named after a Discworld character Exquisitor Vorbis in Small Gods by Sir Terry Pratchett. Compared to Vorbis, Opus can simultaneously achieve higher compression efficiency-per both Xiph.Org itself and third-party listening tests -and lower encode/decode latency (in most cases, low enough for real-time applications such as internet telephony or live singing, rarely possible with Vorbis). Since February 2013, Xiph.Org has stated that the use of Vorbis should be deprecated in favor of the Opus codec, which is also a Xiph.Org Foundation project and also free and open-source. A stable version (1.0) of the reference software was released on July 19, 2002. Originally licensed as LGPL, in 2001 the Vorbis license was changed to the BSD license to encourage adoption, with the endorsement of Richard Stallman. They continued refining the source code until the Vorbis file format was frozen for 1.0 in May 2000. Chris Montgomery began work on the project and was assisted by a growing number of other developers. The Vorbis project started as part of the Xiphophorus company's Ogg project (also known as OggSquish multimedia project). Intensive development began following a September 1998 letter from the Fraunhofer Society announcing plans to charge licensing fees for the MP3 audio format. Vorbis is a continuation of audio compression development started in 1993 by Chris Montgomery. Vorbis is most commonly used in conjunction with the Ogg container format and it is therefore often referred to as Ogg Vorbis. The project produces an audio coding format and software reference encoder/decoder ( codec) for lossy audio compression. Vorbis is a free and open-source software project headed by the Xiph.Org Foundation.
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