Ogg is a

free Free may refer to: Concept * Freedom, having the ability to do something, without having to obey anyone/anything * Freethought, a position that beliefs should be formed only on the basis of logic, reason, and empiricism * Emancipate, to procur ...

, open

container format A container format (informally, sometimes called a wrapper) or metafile is a file format that allows multiple data streams to be embedded into a single file, usually along with metadata for identifying and further detailing those streams. Notab ...

maintained by the

Xiph.Org Foundation Xiph.Org Foundation is a nonprofit organization that produces free multimedia formats and software tools. It focuses on the Ogg family of formats, the most successful of which has been Vorbis, an open and freely licensed audio format and codec d ...

. The authors of the Ogg format state that it is unrestricted by software patents and is designed to provide for efficient

streaming Streaming media is multimedia that is delivered and consumed in a continuous manner from a source, with little or no intermediate storage in network elements. ''Streaming'' refers to the delivery method of content, rather than the content it ...

and manipulation of high-quality

digital multimedia Multimedia is a form of communication that uses a combination of different content forms such as text, audio, images, animations, or video into a single interactive presentation, in contrast to tradition ...

. Its name is derived from "ogging", jargon from the computer game '' Netrek''. The Ogg container format can multiplex a number of independent

streams A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream ...

for

audio Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound *Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum *Digital audio, representation of sound ...

, video, text (such as

subtitles Subtitles and captions are lines of dialogue or other text displayed at the bottom of the screen in films, television programs, video games or other visual media. They can be transcriptions of the screenplay, translations of it, or informati ...

), and

metadata Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive ...

. In the Ogg multimedia framework, Theora provides a lossy video layer. The audio layer is most commonly provided by the music-oriented Vorbis

format Format may refer to: Printing and visual media * Text formatting, the typesetting of text elements * Paper formats, or paper size standards * Newspaper format, the size of the paper page Computing * File format, particular way that informatio ...

or its successor Opus. Lossless audio compression formats include

FLAC FLAC (; Free Lossless Audio Codec) is an audio coding format for lossless compression of digital audio, developed by the Xiph.Org Foundation, and is also the name of the free software project producing the FLAC tools, the reference software p ...

, and

OggPCM Ogg is a free, open container format maintained by the Xiph.Org Foundation. The authors of the Ogg format state that it is unrestricted by software patents and is designed to provide for efficient streaming and manipulation of high-quality d ...

. Before 2007, the .ogg filename extension was used for all files whose content used the Ogg container format. Since 2007, the Xiph.Org Foundation recommends that .ogg only be used for Ogg Vorbis audio files. The Xiph.Org Foundation decided to create a new set of file extensions and media types to describe different types of content such as .oga for audio only files, .ogv for video with or without sound (including Theora), and .ogx for multiplexed Ogg. As of November 7, 2017, the current version of the Xiph.Org Foundation's reference implementation is libogg 1.3.3. Another version, libogg2, has been in development, but is awaiting a rewrite as of 2018. Both

software libraries In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and subro ...

are free software, released under the New BSD License. Ogg reference implementation was separated from Vorbis on September 2, 2000.Xiph.Org (2002-07-19
Ogg releases - libogg-1.0.tar.gz - CHANGES
. Retrieved 2009-09-01. Because the format is free, and its reference implementation is not subject to restrictions associated with copyright, Ogg's various codecs have been incorporated into a number of different free and

proprietary {{Short pages monitor one or more METADATA_BLOCK_PICTURE=… in a ''VorbisComment'' for thumbnails and cover art have Base64-encoded values of the corresponding

METADATA_BLOCK_PICTURE. In other words, FLAC stores thumbnails and cover art in binary blocks—outside of the FLAC tags in a little-endian METADATA_BLOCK_VORBIS_COMMENT. Other existing and proposed mechanisms are: *

metadata blocks * Ogg Skeleton *

Continuous Media Markup Language Continuous Media Markup Language (CMML) is to audio or video what HTML is to text. CMML is essentially a timed text codec. It allows file creators to structure a time-continuously sampled data file by dividing it into temporal sections (also called ...

(deprecated)

History

The Ogg project began with a simple audio compression package as part of a larger project in 1993. The software was originally named ''Squish'' but due to an existing trade mark it was renamed to '' OggSquish''. This name was later used for the whole Ogg project. In 1997, the Xiphophorus OggSquish was described as "an attempt both to create a flexible compressed audio format for modern audio applications as well as to provide the first audio format that is common on any and every modern computer platform". The OggSquish was in 2000 referred to as "a group of several related multimedia and signal processing projects". In 2000, two projects were in active development for planned release: Ogg Vorbis format and libvorbis—the reference implementation of Vorbis. Research also included work on future video and lossless audio coding. In 2001, OggSquish was renamed to ''Ogg'' and it was described as "the umbrella for a group of several related multimedia and signal processing projects". Ogg has come to stand for the

file format A file format is a standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary or free. Some file formats ...

, as part of the larger Xiph.org multimedia project. Squish became just the name of one of the Ogg codecs. In 2009, Ogg is described as "a multimedia container format, and the native file and stream format for the Xiph.org multimedia codecs". The Ogg reference implementation was separated from Vorbis on September 2, 2000. In May 2003, two Internet RFCs were published relating to the format. The Ogg bitstream was defined in (which is classified as 'informative') and its Internet content type (application/ogg) in (which is, , a proposed standard protocol). In September 2008, RFC 3534 was obsoleted by , which added content types video/ogg, audio/ogg and filename extensions .ogx, .ogv, .oga, .spx.

OGM

In 2002, the lack of formal video support in Ogg resulted in the development of the ''OGM'' file format, a hack on Ogg that allowed embedding of video from the Microsoft DirectShow framework into an Ogg-based wrapper. OGM was initially supported only by closed source Windows-only tools, but the codebase was subsequently opened. Later, video (and subtitle) support were formally specified for Ogg but in a manner incompatible with OGM. Independently, the Matroska container format reached maturity and provided an alternative for people interested in combining Vorbis audio and arbitrary video codecs. As a result, OGM is no longer supported or developed and is formally discouraged by Xiph.org. Today, video in Ogg is found with the .ogv file extension, which is formally specified and officially supported. Software and codecs that support .ogm files are available without charge.

2006

Although Ogg had not reached anywhere near the ubiquity of the MPEG standards (e.g., MP3/ MP4), , it was commonly used to encode free content (such as free music, multimedia on Wikimedia Foundation projects and

Creative Commons Creative Commons (CC) is an American non-profit organization and international network devoted to educational access and expanding the range of creative works available for others to build upon legally and to share. The organization has release ...

files) and had started to be supported by a significant minority of digital audio players. Also supporting the Ogg format were many popular video game engines, including '' Doom 3'', '' Unreal Tournament 2004'', '' Halo: Combat Evolved'', '' Jets'n'Guns'', '' Mafia: The City of Lost Heaven'', '' Myst IV: Revelation'', '' StepMania'', '' Serious Sam: The Second Encounter'', ''

Lineage 2 ''Lineage II'' is a massively multiplayer online role-playing game (MMORPG) for Microsoft Windows and the second game in the ''Lineage'' series. It is a prequel to ''Lineage'' and is set 150 years before the first game. It has become popular sin ...

'', '' Vendetta Online'', ''

Battlefield 2 ''Battlefield 2'' is a first-person shooter video game, developed by DICE (company), DICE and published by Electronic Arts for Microsoft Windows in June 2005 as the third game in the Battlefield (video game series), ''Battlefield'' franchise. P ...

'', and the '' Grand Theft Auto'' engines, as well as the audio files of the Java-based game, '' Minecraft''. The more popular Vorbis codec had built-in support on many software players, and extensions were available for nearly all the rest.

2007

On May 16, 2007, the Free Software Foundation started a campaign to increase the use of Vorbis "as an ethically, legally and technically superior audio alternative to the proprietary MP3 format". People were also encouraged to support the campaign by adding a web button to their website or blog. For those who did not want to download and use the FSF's suggested Ogg player ( VLC), the

had an official codec for

QuickTime QuickTime is an extensible multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. Created in 1991, the latest Mac version, QuickTime X, is avai ...

-based applications in Windows and Mac OS X, such as

iTunes iTunes () is a software program that acts as a media player, media library, mobile device management utility, and the client app for the iTunes Store. Developed by Apple Inc., it is used to purchase, play, download, and organize digital mul ...

players and

iMovie iMovie (known at times as iMovie HD) is a preinstalled video editing application developed by Apple Inc. for macOS, iOS, and iPadOS devices. It was originally released in 1999 as a Mac OS 8 application bundled with the first FireWire-enabled ...

applications; and Windows users could install a Windows Media Player Ogg codec.

2009

By June 30, 2009, the Ogg container, through the use of the Theora and Vorbis, was the only container format included in

Firefox 3.5 Mozilla Firefox 3.5 is a version of the Firefox web browser released in June 2009, adding a variety of new features to Firefox. Version 3.5 was touted as being twice as fast as 3.0 (due its TraceMonkey JavaScript engine and rendering improveme ...

web browser's implementation of the HTML5 <video> and <audio> elements. This was in accordance with the original recommendation outlined in, but later removed from, the HTML5 draft specification (see

Ogg controversy The HTML5 draft specification adds video and audio elements for embedding video and audio in HTML documents. The specification had formerly recommended support for playback of Theora video and Vorbis audio encapsulated in Ogg containers to provid ...

2010

On March 3, 2010, a technical analysis by an FFmpeg developer was critical about the general purpose abilities of Ogg as a multimedia container format. The author of Ogg later responded to these claims in an article of his own.

Ogg codecs

Ogg is only a container format. The actual audio or video encoded by a codec is stored inside an Ogg container. Ogg containers may contain streams encoded with multiple codecs; for example, a video file with sound contains data encoded by both an audio codec and a video codec. Being a container format, Ogg can embed audio and video in various formats (such as Dirac,

MNG Multiple-image Network Graphics (MNG) is a graphics file format, published in 2001, for animated images. Its specification is publicly documented and there are free software Free software or libre software is computer software distribute ...

CELT The Celts (, see pronunciation for different usages) or Celtic peoples () are. "CELTS location: Greater Europe time period: Second millennium B.C.E. to present ancestry: Celtic a collection of Indo-European peoples. "The Celts, an ancient ...

MPEG-4 MPEG-4 is a group of international standards for the compression of digital audio and visual data, multimedia systems, and file storage formats. It was originally introduced in late 1998 as a group of audio and video coding formats and related tec ...

, MP3 and others) but Ogg was intended to be, and usually is, used with the following

Xiph.org Xiph.Org Foundation is a nonprofit organization that produces free multimedia formats and software tools. It focuses on the Ogg family of formats, the most successful of which has been Vorbis, an open and freely licensed audio format and codec de ...

free codecs: * Audio ** Lossy *** Speex: handles voice data at low bitrates (~2.1–32 kbit/s/channel) *** Vorbis: handles general audio data at mid to high-level variable bitrates (≈16–500 kbit/s per channel) *** Opus: handles voice, music and generic audio at low and high variable bitrates (≈6–510 kbit/s per channel) ** Lossless ***

handles archival and high-fidelity audio data. *** OggPCM allows storing standard uncompressed

PCM Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amp ...

audio in an Ogg container * Video ** Lossy *** Theora: based upon

On2 On2 Technologies, formerly known as The Duck Corporation, was a small publicly traded company (on the American Stock Exchange), founded in New York City in 1992 and headquartered in Clifton Park, New York, that designed video codec technology. It ...

VP3 On2 TrueMotion VP3 is a (royalty-free) lossy video compression format and video codec. It is an incarnation of the TrueMotion video codec, a series of video codecs developed by On2 Technologies. There is no formal specification for the VP3 bits ...

, it is targeted at competing with

video (for example, encoded with DivX or Xvid),

RealVideo RealVideo, or also spelled as Real Video, is a suite of proprietary video compression formats developed by RealNetworks – the specific format changes with the version. It was first released in 1997 and was at version 10. RealVideo is supported ...

, or Windows Media Video. *** Daala: a video coding format under development. *** Tarkin: an experimental and now obsolete video codec developed in 2000, 2001 and 2002 utilizing discrete wavelet transforms in the three dimensions of width, height, and time. It has been put on hold after Theora became the main focus for video encoding (in August 2002). *** Dirac: a free and open video format developed by the BBC. Uses wavelet encoding. ** Lossless *** Dirac: a part of the specification of dirac covers lossless compression. *** Daala: a video coding format under development. * Text **

: a text/application codec for timed metadata, captioning, and formatting. **

Annodex Annodex is a digital media format developed by CSIRO to provide annotation and indexing of ''continuous media'', such as audio and video. It is based on the Ogg container format, with an XML language called CMML (Continuous Media Markup Langua ...

: A free and open source set of standards developed by

CSIRO The Commonwealth Scientific and Industrial Research Organisation (CSIRO) is an Australian Government The Australian Government, also known as the Commonwealth Government, is the national government of Australia, a federal parliamentar ...

to annotate and index networked media. ** OggKate: An overlay codec, originally designed for karaoke and text, that can be multiplexed in Ogg.

Media types

Ogg audio media is registered as

IANA The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Interne ...

media type A media type (also known as a MIME type) is a two-part identifier for file formats and format contents transmitted on the Internet. The Internet Assigned Numbers Authority (IANA) is the official authority for the standardization and publication o ...

audio/ogg with file extensions .oga, .ogg, and .spx Speex is an audio compression codec specifically tuned for the reproduction of human speech and also a free software speech codec that may be used on VoIP applications and podcasts. It is based on the CELP speech coding algorithm.Xiph.OrIntro .... It is a proper subset of the Ogg video media type video/ogg with file extension .ogv. Other Ogg applications use media type application/ogg with file extension .ogx, this is a superset of video/ogg. The Opus media type audio/opus with file extension .opus was registered later in

RFC RFC may refer to: Computing * Request for Comments, a memorandum on Internet standards * Request for change, change management * Remote Function Call, in SAP computer systems * Rhye's and Fall of Civilization, a modification for Sid Meier's Civ ...

and .

References

External links

* /www.xiph.org/ogg/ The Xiph.Org Foundation official webpage — Ogg*
Using Creative Commons Metadata in Ogg containers

from the

Jargon File The Jargon File is a glossary and usage dictionary of slang used by computer programmers. The original Jargon File was a collection of terms from technical cultures such as the MIT AI Lab, the Stanford AI Lab (SAIL) and others of the old ARPANET A ...

* /xiph.org/quicktime/ Xiph.Org's official Ogg QuickTime Components for iTunes and iMovie (Windows and Mac OS X)
Windows Media Player codecs for Vorbis, Speex, Theora and FLAC

ffmpeg2theora
Ogg Theora encoder, commandline application for Linux and Win32 {{Xiph.org Digital container formats Filename extensions Free digital container formats Open formats Xiph.Org projects