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 patent
A software patent is a patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabl ...
s and is designed to provide for efficient
streaming and manipulation of high-quality
digital multimedia. Its name is derived from "ogging",
jargon
Jargon is the specialized terminology associated with a particular field or area of activity. Jargon is normally employed in a particular communicative context and may not be well understood outside that context. The context is usually a partic ...
from the computer game ''
Netrek
''Netrek'' is an Internet game for up to 16 players, written almost entirely in cross-platform
In computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is comput ...
''.
The Ogg container format can
multiplex a number of independent
streams
A stream is a continuous body of surface water flowing within the bed and bank
A bank is a financial institution that accepts deposits from the public and creates a demand deposit while simultaneously making loans. Lending act ...
for
audio,
video
Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) ...
, text (such as
subtitles), 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
In information technology
Information technology (IT) is the use of computer
A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations ( computation) automatically. Modern digita ...
video layer. The
audio layer is most commonly provided by the music-oriented
Vorbis
Vorbis is a free and open-source software
Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software
Free software or libre software is computer software distributed under terms ...
format or its successor
Opus.
Lossless audio compression formats include
FLAC
FLAC (; Free Lossless Audio Codec) is an audio coding format
An audio coding format (or sometimes audio compression format) is a content representation format for storage or transmission of digital audio
Digital audio is a representa ...
, and
OggPCM.
Before 2007, the .ogg
filename extension
A filename extension, file name extension or file extension is a suffix to the name of a computer file (e.g., .txt, .docx, .md). The extension indicates a characteristic of the file contents or its intended use. A filename extension is typically ...
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 are
free software
Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, ...
, 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
A copyright is a type of intellectual property
Intellectual property (IP) is a category of property
Property is a system of rights that gives people legal control of valuable things, and also refers to the valuable things themselv ...
, Ogg's various
codec
A codec is a device or computer program
A computer program is a sequence or set of instructions in a programming language
A programming language is a system of notation for writing computer programs. Most programming languages are text-b ...
s have been incorporated into a number of different free and
proprietary media players, both commercial and non-commercial, as well as
portable media player
A portable media player (PMP) (also including the related digital audio player (DAP)) is a portable consumer electronics device capable of storing and playing digital media
Digital media is any communication media that operate in conjunc ...
s and
GPS receivers from different manufacturers.
Naming
Ogg is derived from "ogging",
jargon
Jargon is the specialized terminology associated with a particular field or area of activity. Jargon is normally employed in a particular communicative context and may not be well understood outside that context. The context is usually a partic ...
from the computer game ''
Netrek
''Netrek'' is an Internet game for up to 16 players, written almost entirely in cross-platform
In computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is comput ...
'', which came to mean doing something forcefully, possibly without consideration of the drain on future resources.
At its inception, the Ogg project was thought to be somewhat ambitious given the limited power of the
PC hardware of the time.
Although it is sometimes assumed that the name "Ogg" comes from the character of
Nanny Ogg in
Terry Pratchett
Sir Terence David John Pratchett (28 April 1948 – 12 March 2015) was an English humourist, satirist, and author of fantasy novels, especially comical works. He is best known for his '' Discworld'' series of 41 novels.
Pratchett's first ...
's ''
Discworld
''Discworld'' is a comic fantasy"Humorous Fantasy" in David Pringle, ed., ''The Ultimate Encyclopedia of Fantasy'' (pp.31-33). London, Carlton,2006. book series written by the English author Terry Pratchett, set on the Discworld, a fla ...
'' novels, the format's developers say that is not true.
Still, to quote the same reference: "Vorbis, on the other hand is named after the Terry Pratchett character from the book ''
Small Gods''".
The
Ogg Vorbis
Vorbis is a free and open-source software project headed by the Xiph.Org Foundation. The project produces an audio coding format and software reference encoder/decoder ( codec) for lossy audio compression. Vorbis is most commonly used in co ...
project started in 1993. It was originally named "Squish" but that name was already trademarked, so the project underwent a name change. The new name, "OggSquish", was used until 2001 when it was changed again to "Ogg". Ogg has since come to refer to the
container format, which is now part of the larger Xiph.org multimedia project. Today, "Squish" (now known as "Vorbis") refers to a particular
audio coding format
An audio coding format (or sometimes audio compression format) is a content representation format for storage or transmission of digital audio
Digital audio is a representation of sound
In physics
Physics is the natural s ...
typically used with the Ogg container format.
File format
The "Ogg"
bitstream format, designed principally by the Xiph.Org Foundation, has been developed as the framework of a larger initiative aimed at producing a set of components for the coding and decoding of multimedia files, which are available free of charge and freely re-implementable in software and hardware.
The format consists of chunks of data each called an "
Ogg page". Each page begins with the characters "OggS" to identify the file as Ogg format.
A "serial number" and "page number" in the page header identifies each page as part of a series of pages making up a
bitstream. Multiple bitstreams may be
multiplexed in the file where pages from each bitstream are ordered by the seek time of the contained data. Bitstreams may also be appended to existing files, a process known as "chaining", to cause the bitstreams to be decoded in sequence.
A
BSD-licensed library, called "libvorbis", is available to encode and decode data from "Vorbis" streams. Independent Ogg implementations are used in several projects such as
RealPlayer and a set of
DirectShow
DirectShow (sometimes abbreviated as DS or DShow), codename Quartz, is a multimedia framework and API produced by Microsoft
Microsoft Corporation is an American multinational corporation, multinational technology company, technology corpor ...
filters.
Mogg, the "Multi-Track-Single-Logical-Stream Ogg-Vorbis", is the multi-channel or multi-track Ogg file format.
Page structure
The following is the field layout of an Ogg page header:
![Ogg page header structure (en)](https://upload.wikimedia.org/wikipedia/commons/e/ee/Ogg_page_header_structure_%28en%29.svg)
;Capture pattern – 32 bits
:The capture pattern or sync code is a
magic number used to ensure synchronization when parsing Ogg files. Every page starts with the four ASCII character sequence, "OggS". This assists in resynchronizing a parser in cases where data has been lost or is corrupted, and is a sanity check before commencing parsing of the page structure.
;Version – 8 bits
:This field indicates the version of the Ogg bitstream format, to allow for future expansion. It is currently mandated to be 0.
;Header type – 8 bits
:This is an 8 bit field of flags, which indicates the type of page that follows.
:
;Granule position – 64 bits
:A granule position is the time marker in Ogg files. It is an abstract value, whose meaning is determined by the codec. It may, for example, be a count of the number of samples, the number of frames or a more complex scheme.
;Bitstream serial number – 32 bits
:This field is a serial number that identifies a page as belonging to a particular logical bitstream. Each logical bitstream in a file has a unique value, and this field allows implementations to deliver the pages to the appropriate decoder. In a typical Vorbis and Theora file, one stream is the audio (Vorbis), and the other is the video (Theora)
;Page sequence number – 32 bits
:This field is a monotonically increasing field for each logical bitstream. The first page is 0, the second 1, etc. This allows implementations to detect when data has been lost.
;
Checksum
A checksum is a small-sized block of data derived from another block of digital data
Digital data, in information theory
Information theory is the scientific study of the quantification, storage, and communication of information. Th ...
– 32 bits
:This field provides a
CRC32
A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to digital data. Blocks of data entering these systems get a short ''check value'' attached, based on ...
checksum of the data in the entire page (including the page header, calculated with the checksum field set to 0). This allows verification that the data has not been corrupted since it was authored. Pages that fail the checksum should be discarded. The checksum is generated using a polynomial value of 0x04C11DB7.
;Page segments – 8 bits
:This field indicates the number of segments that exist in this page. It also indicates how many bytes are in the segment table that follows this field. There can be a maximum of 255 segments in any one page.
;Segment table
:The segment table is an array of 8-bit values, each indicating the length of the corresponding segment within the page body. The number of segments is determined from the preceding page segments field. Each segment is between 0 and 255 bytes in length.
The segments provide a way to group segments into packets, which are meaningful units of data for the decoder. When the segment's length is indicated to be 255, this indicates that the following segment is to be concatenated to this one and is part of the same packet. When the segment's length is 0–254, this indicates that this segment is the final segment in this packet. Where a packet's length is a multiple of 255, the final segment is length 0.
Where the final packet continues on the next page, the final segment value is 255, and the continuation flag is set on the following page to indicate that the start of the new page is a continuation of last page.
Metadata
VorbisComment is a base-level Metadata format initially authored for use with Ogg Vorbis. It has since been adopted in the specifications of Ogg encapsulations for other Xiph.Org codecs including
Theora,
Speex
Speex is an audio compression codec specifically tuned for the reproduction of human speech and also a free software
Free software or libre software is computer software distributed under terms that allow users to run the software for an ...
,
FLAC
FLAC (; Free Lossless Audio Codec) is an audio coding format
An audio coding format (or sometimes audio compression format) is a content representation format for storage or transmission of digital audio
Digital audio is a representa ...
and
Opus. ''VorbisComment'' is the simplest and most widely-supported mechanism for storing metadata with Xiph.Org codecs.
Notably, one or more
METADATA_BLOCK_PICTURE=… in a ''VorbisComment'' for thumbnails and cover art have
Base64
In computer programming, Base64 is a group of binary-to-text encoding schemes that represent binary data (more specifically, a sequence of 8-bit byte
The byte is a unit of digital information that most commonly consists of eight bits. His ...
-encoded values of the corresponding
FLAC
FLAC (; Free Lossless Audio Codec) is an audio coding format
An audio coding format (or sometimes audio compression format) is a content representation format for storage or transmission of digital audio
Digital audio is a representa ...
METADATA_BLOCK_PICTURE. In other words, FLAC stores thumbnails and cover art in binary blocks—outside of the FLAC tags in a
little-endian
In computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithm
In mathematics
Mathematics is an area of knowledge th ...
METADATA_BLOCK_VORBIS_COMMENT.
Other existing and proposed mechanisms are:
*
FLAC
FLAC (; Free Lossless Audio Codec) is an audio coding format
An audio coding format (or sometimes audio compression format) is a content representation format for storage or transmission of digital audio
Digital audio is a representa ...
metadata blocks
* Ogg Skeleton
*
Continuous Media Markup Language
Continuous Media Markup Language (CMML) is to audio or video what HTML
The HyperText Markup Language or HTML is the standard markup language
Markup language refers to a text-encoding system consisting of a set of symbols inserted in a ...
(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 form ...
, 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
DirectShow (sometimes abbreviated as DS or DShow), codename Quartz, is a multimedia framework and API produced by Microsoft
Microsoft Corporation is an American multinational corporation, multinational technology company, technology corpor ...
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
Matroska is a project to create a container format that can hold an unlimited number of video, audio, picture, or subtitle tracks in one file. The Matroska Multimedia Container is similar in concept to other containers like AVI, MP4, or Adv ...
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
The Moving Picture Experts Group (MPEG) is an alliance of working group
A working group, or working party, is a group of experts working together to achieve specified goals. The groups are domain-specific and focus on discussion or activi ...
standards (e.g.,
MP3/
MP4), , it was commonly used to encode
free content (such as free music, multimedia on
Wikimedia Foundation
The Wikimedia Foundation, Inc., or Wikimedia for short and abbreviated as WMF, is an American 501(c)(3) nonprofit organization
A nonprofit organization (NPO) or non-profit organisation, also known as a non-business entity, not-for-p ...
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 relea ...
files) and had started to be supported by a significant minority of
digital audio player
A portable media player (PMP) (also including the related digital audio player (DAP)) is a portable consumer electronics
Consumer electronics or home electronics are electronic ( analog or digital) equipment intended for everyday use, ...
s. Also supporting the Ogg format were many popular video game engines, including ''
Doom 3
''Doom 3'' is a 2004 survival horror first-person shooter
First-person shooter (FPS) is a video game genre, sub-genre of shooter video games centered on gun and other weapon-based combat in a First person (video games), first-person persp ...
'', ''
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'', ''
Vendetta Online'', ''
Battlefield 2'', and the ''
Grand Theft Auto
''Grand Theft Auto'' (''GTA'') is a series of action-adventure game
The action-adventure genre is a video game hybrid genre that combines core elements from both the action game and adventure game genres.
Typically, pure adventure ...
'' engines, as well as the audio files of the
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consist ...
-based game, ''
Minecraft
''Minecraft'' is a sandbox game developed by Mojang Studios. The game was created by Markus "Notch" Persson in the Java (programming language), Java programming language. Following several early private testing versions, it was first made pub ...
''. 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
The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization
A nonprofit organization (NPO) or non-profit organisation, also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal ...
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
A website (also written as a web site) is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. Examples of notable websites are Google, Facebook, Amazon, and ...
or
blog
A blog (a truncation of "weblog") is a discussion or informational website published on the World Wide Web
The World Wide Web (WWW), commonly known as the Web, is an information system enabling documents and other web resources ...
. For those who did not want to download and use the FSF's suggested Ogg player (
VLC), the
Xiph.Org Foundation 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 ...
-based applications in
Windows
Windows is a group of several Proprietary software, proprietary graphical user interface, graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, W ...
and
Mac OS X
macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac (computer), Mac computers. Within the market of ...
, such as
iTunes
iTunes () is a software program that acts as a media player, media library, mobile device
A mobile device (or handheld computer) is a computer small enough to hold and operate in the hand. Mobile devices typically have a flat LCD or OLE ...
players and
iMovie
iMovie (known at times as iMovie HD) is a preinstalled video editing
Video editing is the manipulation and arrangement of video
Video is an electronic medium for the recording, copying, playback, broadcasting, and display of movi ...
applications; and Windows users could install a
Windows Media Player
Windows Media Player (WMP) is the first media player and media library application that was developed by Microsoft
Microsoft Corporation is an American multinational corporation, multinational technology company, technology corporation ...
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 web browser's implementation of the
HTML5
HTML5 is a markup language
Markup language refers to a text-encoding system consisting of a set of symbols inserted in a text document to control its structure, formatting, or the relationship between its parts. Markup is often used to con ...
<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).
2010
On March 3, 2010, a technical analysis by an
FFmpeg
FFmpeg is a free and open-source software project consisting of a suite of libraries
A library is a collection of materials, books or media that are accessible for use and not just for display purposes. A library provides physical (hard co ...
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,
CELT
The Celts (, see pronunciation
Pronunciation is the way in which a word or a language
Language is a structured system of communication. The structure of a language is its grammar and the free components are its vocabulary. Lang ...
,
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 ...
,
MP3 and others) but Ogg was intended to be, and usually is, used with the following
Xiph.org free codecs:
* Audio
**
Lossy
In information technology
Information technology (IT) is the use of computer
A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations ( computation) automatically. Modern digita ...
***
Speex
Speex is an audio compression codec specifically tuned for the reproduction of human speech and also a free software
Free software or libre software is computer software distributed under terms that allow users to run the software for an ...
: handles voice data at low bitrates (~2.1–32 kbit/s/channel)
***
Vorbis
Vorbis is a free and open-source software
Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software
Free software or libre software is computer software distributed under terms ...
: 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
***
FLAC
FLAC (; Free Lossless Audio Codec) is an audio coding format
An audio coding format (or sometimes audio compression format) is a content representation format for storage or transmission of digital audio
Digital audio is a representa ...
handles archival and high-fidelity audio data.
*** OggPCM allows storing standard uncompressed
PCM audio in an Ogg container
* Video
**
Lossy
In information technology
Information technology (IT) is the use of computer
A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations ( computation) automatically. Modern digita ...
***
Theora: based upon
On2's
VP3, it is targeted at competing with
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 ...
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
RealNetworks, Inc. is a provider of artificial intelligence and computer vision based products. RealNetworks was a pi ...
, 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 transform
In numerical analysis and functional analysis, a discrete wavelet transform (DWT) is any wavelet transform
In mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes ...
s in the three
dimension
In physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of ...
s 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
**
Continuous Media Markup Language
Continuous Media Markup Language (CMML) is to audio or video what HTML
The HyperText Markup Language or HTML is the standard markup language
Markup language refers to a text-encoding system consisting of a set of symbols inserted in a ...
: a text/application codec for timed metadata, captioning, and formatting.
**
Annodex
Annodex is a digital media
Digital media is any communication media that operate in conjunction with various encoded machine-readable data formats. Digital media can be created, viewed, distributed, modified, listened to, and preserved on a ...
: A free and open source set of standards developed by
CSIRO
The Commonwealth Scientific and Industrial Research Organisation (CSIRO) is an Australian Government agency responsible for scientific research.
CSIRO works with leading organisations around the world. From its headquarters in Canberra, CSIRO ...
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 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 (or internet) is the global system of interconnected computer networks that uses the Inter ...
audio/ogg with file extensions
.oga,
.ogg, and
.spx. 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 and .
See also
*
Audio data compression
In information theory
Information theory is the scientific study of the quantification, storage, and communication of information. The field was originally established by the works of Harry Nyquist and Ralph Hartley, in the 1920s, and ...
*
Comparison of audio coding formats
The following tables compare general and technical information for a variety of audio coding formats.
For listening tests comparing the perceived audio quality of audio formats and codecs, see the article Codec listening test.
General informat ...
*
Comparison of container formats
*
Commons:file types
*
Use of Ogg formats in HTML5
*
Wikimedia Commons' Theora video conversion help page
*
Wikipedia:Media help (Ogg) Installing audio and video software
References
External links
*
/www.xiph.org/ogg/ The Xiph.Org Foundation official webpage — Ogg*
Using Creative Commons Metadata in Ogg containersfrom the
Jargon File
The Jargon File is a glossary and usage dictionary of slang
Slang is vocabulary (words, phrases, and linguistic usages) of an informal register, common in spoken conversation but avoided in formal writing. It also sometimes refers to the ...
*
/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 FLACffmpeg2theoraOgg Theora encoder, commandline application for Linux and
Win32
{{Xiph.org
Digital container formats
Filename extensions
Free digital container formats
Open formats
Xiph.Org projects