Science Fair Project Encyclopedia
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 "Monty" Montgomery began work on the project, he was assisted by a growing collection of other developers. They continued refining the code until a stable version 1.0 of the codec was released on July 19, 2002.
The latest version is 1.1.0 released on 2004-09-22 . Source code for this release is available from the official Vorbis web site, while many Windows binaries can be downloaded at Rarewares. A simple guide to producing good Ogg Vorbis files from a CD is available here.
The Ogg Vorbis format has proved popular among open source communities; they argue that its higher fidelity and completely free nature make it a natural replacement for the entrenched MP3 format. However, MP3 has a popular history dating back to the mid-1990s and as of 2004 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 (with Epic Games' Unreal Tournament 2003 being the most notable example). The increasing number of hardware players that support Vorbis is encouraging its growth as of July 2004; see the compatible hardware below. As to software players, virtually all of the popular ones can play Vorbis "out of the box", with a few of them needing an external plug-in; see the compatible software below. Another proof of Ogg Vorbis entering mainstream is the increasing number of music websites using Ogg, like Jamendo or Mindawn .
Many other lossy audio codecs exist, including:
- MPEG-4 AAC, used by LiquidAudio and Apple Computer's iTunes Music Store;
- AC-3, used in Dolby Digital and DVD;
- ATRAC, used in Sony's Minidisc;
- MP2, MPEG-1/2 Audio Layer 2, MP3's predecessor;
- mp3PRO from Thomson Multimedia combining MP3 with SBR;
- MPC, also known as Musepack (formerly MP+), a derivative of MP2;
- QDesign, used in QuickTime at high bitrates;
- AMR-WB+ Enhanced Adaptive Multi Rate WideBand codec, optimized for cellular and other limited bandwidth use;
- RealAudio from RealNetworks, frequently in use for streaming on websites;
- WMA (Windows Media Audio) from Microsoft, which like MP3 is widely supported by hardware devices;
Listening tests  have attempted to find the best quality lossy audio codecs at certain bitrates. The tests show that: at 128kbps, Ogg Vorbis and MPC performed marginally better than other codecs. At 64kbps, AAC and mp3pro performed marginally better than other codecs. At higher bitrates (128kbps+), most people do not hear significant differences.
Based on this, Vorbis can be considered a high quality codec. For most applications Vorbis is a good codec to use, but would only be considered superior to other modern codecs because it is patent free.
Given 44.1 kHz (standard CD audio sample frequency) stereo input, the current encoder as of September 2004 will produce output from 45 to 500 kbit/s depending on the specified quality setting. Quality settings run from -1 to 10 and are an arbitrary metric; files encoded at -q5, for example, should have the same quality of sound in all versions of the encoder, but newer versions should be able to achieve that quality with a lower bitrate. Vorbis is inherently variable-bitrate (VBR).
Vorbis uses the modified discrete cosine transform (MDCT) for converting sound data from the time domain to the frequency domain. 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. The decompression algorithm reverses these stages.
Many users feel that Vorbis reaches 'transparency' (sound quality that is indistinguishable from the original source recording) at a quality setting of -q5, approximately 160kps. For comparison, it is commonly felt that MP3 reaches transparency at around 192kps, resulting in larger file sizes for the same sound quality.
Various 'tuned' versions of the encoder (Garf, aoTuV or MegaMix) attempt to provide better sound at a specified quality setting, usually by dealing with certain problematic waveforms by temporarily increasing the bitrate. The most consistently cited problem with Vorbis is 'pre-echo', a faint copy of a sharp attack that occurs just before the actual sound (the sound of castanets is commonly cited as causing this effect). Most of the 'tuned' versions of Vorbis attempt to fix this problem and to increase the sound quality of lower quality settings (-q0 through -q4). Some of the tuning suggestions created by the Vorbis user community (especially the aoTuV tunings) have been incorporated into the 1.1.0 release.
The Vorbis format supports bitrate peeling for reducing the bitrate of already encoded files, although no encoder has implemented this feature yet.
Knowledge of Vorbis's specifications is in the public domain. Concerning the specification itself, Xiph.org reserves the right to set the Vorbis specification and certify compliance. Its libraries are released under a BSD-style license and its tools are released under the GPL (GNU General Public License).
The Xiph.org Foundation says that Vorbis, like all its developments, is completely free from the licensing or patent issues raised by other proprietary formats such as MP3. Although Xiph says it has conducted a patent search that supports its claims, outside parties (notably engineers working on rival formats) have expressed doubt that Vorbis is free of patented technology. Xiph says that it was privately issued a legal opinion subject to attorney/client privilege. It has not released an official statement on the patent status of Vorbis, pointing out that such a statement is technically impossible due to the number and scope of patents in existence and the questionable validity of many of them. Such issues cannot be resolved outside of a court of law. Some Vorbis proponents have derided the uncertainty concerning the patent status as "FUD": disinformation spread by large companies with a vested interest.
Ogg Vorbis is supported by several large digital audio player manufacturers such as Rio, Neuros and iRiver. Many feel that the growing support for the Vorbis codec within the industry supports their interpretation of its patent status, as multinational corporations are unlikely to distribute software with questionable legal status. The same could be said about its growing popularity in other commercial enterprises like mainstream computer games.
Hardware and software support
Tremor, a version of the Vorbis decoder which uses fixed-point arithmetic (rather than floating point) was made available to the public on September 2, 2002 (also under a BSD-style license). Tremor, or platform specific versions based on it, is more suited to implementation on the limited facilities available in commercial audio systems (such as portable players). A number of versions, which make adjustments for specific platforms, and which include customised optimisations for given embedded microprocessors, have been produced. Several hardware manufacturers have expressed an intention to produce Vorbis-compliant devices, and new Vorbis devices seem to be appearing at a steady rate, especially in South Korea, although availability might differ from country to country.
The VorbisHardware node at the xiph.org wiki has an up-to-date list of Vorbis-supporting hardware, such as portables, PDAs, and microchips.
Here are a few examples of devices that play Ogg Vorbis files:
- All iRiver harddisk players (except H10 and N10) support Ogg Vorbis. Most of the flash-memory players will play Ogg Vorbis without a firmware upgrade.
- The Neuros (site) portable player released a firmware upgrade offering Ogg Vorbis support after a beta testing period in the latter half of 2003. Firmware versions 1.45 and newer support Ogg Vorbis.
- Rio Karma, an mp3 player supporting both Ogg Vorbis and FLAC.
- The Jens of Sweden MP-130 (site) supports Ogg Vorbis.
- The Xclef HD800  supports Ogg Vorbis amongst other formats.
- Cowon iAudio M3 
- Samsung YP-60V, and the Samsung YP-MT6 series supports Ogg right out of the box.
- KiSS DVD-Players (site) are supporting Ogg Vorbis, MP3 and WMA. Some models have an Ethernet port allowing to stream audio and video from a PC on the network or listen to Web radio.
- The Muzio JM-200, 250, 300, H1000 (site) all support Ogg Vorbis (through firmware upgrade for the 200/250 models).
Again, the VorbisSoftwarePlayers node at the xiph.org wiki has an up-to-date list of Vorbis-supporting software for all operating systems. You can test these players using the list of Vorbis audio streams avaiable at .
Ogg Vorbis (as of 2003) can be played using these (and other) players:
- ogg123 for Unix-like systems (GPL), a simple but sufficient commandline player
- Beep Media Player for Unix-like systems (GPL), an XMMS fork
- XMMS for Unix-like systems (GPL) [formerly known as X11amp]
- MPlayer for Unix-like systems (GPL)
- Rhythmbox for Unix-like systems, GNOME based and GPL
- amaroK for Unix-like systems, KDE based and GPL
- zinf for Linux and Windows (GPL) [formerly known as FreeAmp]
- Winamp for Windows (freeware)
- JetAudio for Windows (freeware)
- JOrbis pure Java (LGPL)
- foobar2000 for Windows (freeware) focused on high quality playback
- GStreamer for Unix-like systems (GPL)
- VLC media player for Windows, Mac OS X, and Unix-like systems. (GPL)
- iRecordMusic, encodes Internet audio streams to Ogg Vorbis on Mac OS X
- PocketOgg for Pocket PC
- PocketMusic for Windows Smartphone
- Quintessential Player for Windows (freeware)
- Sonique for Windows (freeware)
- Pocket Tunes for PalmOS 5
- AeroPlayer for PalmOS 5
- Symbian OggPlay for Symbian OS (Series 60 as well as UIQ) based Smartphones
- XMPlay for Windows (freeware)
- dBpowerAMP for Windows
- Vorbis can be played by Microsoft's Windows Media Player using an Ogg Vorbis DirectShow filter available at ; a different DirectShow filter is available at .
- There is a QuickTime component available at the qtcomponents SourceForge project. This allows Vorbis audio to be played by the popular iTunes software.
- mp3blaster for Unix-like systems, ncurses based
"Ogg" is not named after the witch Nanny Ogg in Terry Pratchett's Discworld books, see Ogg for the correct definition. However, "Vorbis" is named after another Discworld character, High Priest Vorbis in Small Gods.
- Help with Ogg Vorbis and playing sound files on Wikipedia
- Ogg bitstream format
- Speex, speech codec
- FLAC, lossless audio codec
- Theora, video codec
- Tarkin, video codec
- Xiph.org Foundation
- Ogg Vorbis site
- modified discrete cosine transform Description
- Christopher "Monty" Montgomery (main developer) interview, slashdot.org
- Listening Tests conducted by Roberto J. Amorim (comparing MP3, Vorbis, AAC, etc)
- Ogg Vorbis binaries at Rarewares
- jamendo.com : Largest archive of Creative Commons licensed Ogg Vorbis music
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