Revision as of 01:14, 18 June 2005

Introduction

Ogg Vorbis (www.vorbis.com) is a fully open, non-proprietary, patent-free (subject to speculation), and royalty-free, general-purpose compressed audio format for mid to high quality (8khz-48.0kHz, 16+ bit, polyphonic) audio and music at fixed and variable bitrates from 16 to >256 kbps/channel. This places vorbis in the same competitive class as audio representations such as MPEG-4 (AAC), and similar to, but higher performance MP3, twinvq (VQF), WMA and PAC.

Vorbis is the first of a planned family of Ogg multimedia coding formats being developed as part of Xiph.org's ogg multimedia project.

Informal listening test suggests Vorbis to be comparable to MPEG-4 AAC at most bitrates and MPC at 128 kbps. Transparency is generally reached at about 150-170 kbps (-q 5) (with some exceptions). The encoder is reasonably young and unoptimized, so further improvements can always be expected.

Vorbis had success with many recent video game titles employing Vorbis as opposed to MP3 (with Epic Games' Unreal Tournament 2003 and Unreal Tournament 2004, the PC port of Microsoft's Halo and Uru being notable examples).

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": misinformation spread by large companies with a vested interest.

Unfortunately, Xiph.org has failed to improve Vorbis at a steady rate since its initial 1.0 release in July 2002 (due to other developement projects and time constraints). Since then development has been lead by other coders such as Garf and Aoyumi. Aoyumi's AoTuV series of encoders was incorporated into the September 2004 release of 1.1, which brought about the first quality improvements across the board for 2 years. Currently Aoyumi is working on AoTuv Beta 4 and future releases.

Pros

Free (as in speech), Open Source and claimed to be patent free
Good all-round performance (>48 kbps - a leading codec at 128 kbps)
Well written specs
Several portable hardware players
Suitable for internet-streaming (via Icecast and other methods)
Fully gapless playback
High potential for further tuning

Cons

Limited official development (third-party developement is always encouraged)
Current implementations are more computationally intensive to encode and decode than MP3 (Vorbis 2.0 seeks to overcome this limitations by slimlining the encoder)
Quality could benefit from further tuning

Technologies used in compression

Advanced psymodel (based upon ATH model)
Coupled stereo modes (point/phase stereo and lossless)
Huffman coding
Vector quantization
Modified Discrete Cosine Transform (MDCT)
Multiple block sizes for window switching
Customly designed window function similiar to the Sine window (good sidelobe rejection).

Software

Encoders

oggenc (Win32/Posix)
oggdropXPd (Win32)
foo_vorbisenc (foobar2000)

Decoders

ogg123 for Unix systems (GPL), a very simple to use command-line player.
OggDec for Windows, by John33, a very featureful command line decoder.
QuickTime Component (Allows playback in QuickTime/iTunes)
CoreVorbis (DirectShow)
illiminable Ogg Directshow Filters (Also plays Speex, Theora and FLAC)

Supported Digital Audio Players

The following list contains some players that support Vorbis playback.

External links

The following links contain information surrounding the Ogg Vorbis codec that can be found on Hydrogenaudio and elsewhere throughtout the web.

Official web site
Ogg (Container)
Ogg Vorbis at Wikipedia.
Ogg Vorbis at AudioCoding
Ogg Vorbis binaries at Rarewares.
[http://www.rjamorim.com/test/ Listening tests comparing Vorbis against MP3, AAC, WMA, etc.)
Recommended settings thread for encoding with Vorbis.
Aoyumi homepage tuned versions of Vorbis 1.1 encoder and current beta binaries.
Archer homepage optimized versions of AoTuV Beta 3 Vorbis encoder and SSE optmizations.
Xiph.org Foundation
Xiph.org Vorbis bounties

@@ Line 5: / Line 5: @@
 Informal listening test suggests Vorbis to be comparable to MPEG-4 [[AAC]] at most bitrates and [[MPC]] at 128 kbps. Transparency is generally reached at about 150-170 kbps (-q 5) (with some exceptions). The encoder is reasonably young and unoptimized, so further improvements can always be expected.
+Vorbis had success with many recent video game titles employing Vorbis as opposed to MP3 (with Epic Games' Unreal Tournament 2003 and Unreal Tournament 2004, the PC port of Microsoft's Halo and Uru being notable examples).
+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": misinformation spread by large companies with a vested interest.
 Unfortunately, Xiph.org has failed to improve Vorbis at a steady rate since its initial 1.0 release in July 2002 (due to other developement projects and time constraints). Since then development has been lead by other coders such as [http://sjeng.org/vorbisgt3.html Garf] and [http://www.geocities.jp/aoyoume/aotuv/ Aoyumi].  Aoyumi's AoTuV series of encoders was incorporated into the September 2004 release of 1.1, which brought about the first quality improvements across the board for 2 years. Currently Aoyumi is working on AoTuv Beta 4 and future releases.
@@ Line 13: / Line 17: @@
 * Good all-round performance (>48 kbps - a leading codec at [http://www.rjamorim.com/test/multiformat128/results.html 128 kbps])
 * Well written [http://www.xiph.org/ogg/vorbis/docs.html specs]
 * Several portable [http://wiki.hydrogenaudio.org/index.php?title=Ogg_Vorbis#Hardware hardware players]
 * Suitable for internet-streaming (via [http://www.icecast.org/ Icecast] and other methods)
 * Fully [[gapless]] playback
 * High potential for further tuning
 ==Cons==
@@ Line 41: / Line 46: @@
 '''Decoders'''
 * [[ogg123]] for Unix systems (GPL), a very simple to use command-line player.
+* [http://www.rarewares.org/ogg.html OggDec] for Windows, by John33, a very featureful command line decoder.
 * [http://qtcomponents.sourceforge.net/ QuickTime Component] (Allows playback in [[QuickTime]]/[[iTunes]])
 * [http://corevorbis.corecodec.org/ CoreVorbis] (DirectShow)
@@ Line 57: / Line 63: @@
 =External links=
 The following links contain information surrounding the Ogg Vorbis codec that can be found on Hydrogenaudio and elsewhere throughtout the web.
+* [http://www.vorbis.com Official web site]
 * [[Ogg]] (Container)
 * [http://en.wikipedia.org/wiki/Vorbis Ogg Vorbis at Wikipedia.]
 * [http://www.audiocoding.com/modules/wiki/?page=Ogg+Vorbis Ogg Vorbis at AudioCoding]
 * [http://www.rarewares.org/ogg.html Ogg Vorbis binaries at Rarewares. ]
-* [http://www.hydrogenaudio.org/show.php/showtopic/13531 Discussion of Vorbis' legal status]
+* [http://www.rjamorim.com/test/ Listening tests comparing Vorbis against MP3, AAC, WMA, etc.)
 * [http://www.hydrogenaudio.org/forums/index.php?showtopic=15049 Recommended settings thread for encoding with Vorbis.]
 * [http://www.geocities.jp/aoyoume/aotuv/ Aoyumi homepage tuned versions of Vorbis 1.1 encoder and current beta binaries.]