Theora is a video codec being developed by the Xiph.Org Foundation as part of their Ogg project. Based upon On2 Technologies' VP3 codec, and christened by On2 as the successor in VP3's lineage, Theora is targeted at competing with MPEG-4 video (e.g., H.264, Xvid and DivX), RealVideo, Windows Media Video, and similar lower-bitrate video compression schemes. A filename extension is a suffix to the name of a computer file applied to show its format. ... Multipurpose Internet Mail Extensions (MIME) is an Internet Standard that extends the format of e-mail to support text in character sets other than US-ASCII, non-text attachments, multi-part message bodies, and header information in non-ASCII character sets. ... A video codec is a device or software module that enables video compression or decompression for digital video. ... Look up Ogg in Wiktionary, the free dictionary. ... Standards are produced by many organizations, some for internal usage only, others for use by a groups of people, groups of companies, or a subsection of an industry. ... Video (Latin for I see, first person singular present, indicative of videre, to see) is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion. ... A Codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. ... The Xiph. ... Look up Ogg in Wiktionary, the free dictionary. ... On2 Technologies is the developer behind the VP5 and VP6 codecs powering the video part of the Chinese-developed competitor to DVD, the EVD (Enhanced Versatile Disc). ... VP3 was originally a proprietary video codec developed by On2 Technologies. ... MPEG-4 is a standard used primarily to compress audio and visual (AV) digital data. ... H.264 is a high compression digital video codec standard written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product of a collective partnership effort known as the Joint Video Team (JVT). ... Xvid (formerly XviD) is a video codec library following the MPEG-4 standard. ... DivX is a brand name of products created by DivX, Inc. ... RealVideo is a proprietary video format developed by RealNetworks. ... Windows Media Video (WMV) is a generic name for the set of video codec technologies developed by Microsoft. ...

While VP3 is patented technology, On2 has irrevocably given royalty-free license of the VP3 patents to everyone, letting anyone use Theora and other VP3-derived codecs for any purpose.

In the Ogg multimedia framework, Theora provides a video layer, while Vorbis usually acts as the audio layer (Speex and FLAC can also act as audio layers). Vorbis is an open source, lossy audio codec project headed by the Xiph. ... Speex is a free software speech codec that claims to be unencumbered by patent restrictions. ... FLAC, an acronym for Free Lossless Audio Codec, is a popular file format for audio data compression. ...

Theora is named for Theora Jones, Edison Carter's Controller on the Max Headroom television program. Theora Jones is a fictional character on the television show Max Headroom. ... Edison Carter was one of the main characters in the science fiction television series Max Headroom. ... Wikiquote has a collection of quotations related to: Max Headroom Max Headroom (1987–1988) was a short-lived but ground-breaking American science fiction television series which aired on ABC. The series was developed from a British television character. ...

Technical details

Theora is a lossy video compression method derived from On2's VP3 Codec. The compressed video can be stored in any suitable container format. At the time of writing (June 2006), Theora video is generally included in Ogg container format. It is frequently paired with Vorbis audio. A lossy data compression method is one where compressing a file and then decompressing it retrieves a file that may well be different to the original, but is close enough to be useful in some way. ... NatusRoma 00:49, 12 Jun 2005 (UTC) Categories: Possible copyright violations ... VP3 was originally a proprietary video codec developed by On2 Technologies. ... A container format is a computer file format that can contain various types of data, compressed by means of standardized codecs. ... For the Manfred Mann album, see 2006 (album). ... Look up Ogg in Wiktionary, the free dictionary. ... Vorbis is an open source, lossy audio codec project headed by the Xiph. ...

The combination of the Ogg container format, Theora video and Vorbis audio allows for a completely open, royalty-free multimedia format. Previous multimedia formats (e.g. MPEG-4 video and MP3 audio) were patented, meaning that Free Software players implementing them were legally vulnerable, because paying license fees for software freely available for everyone to use anywhere for anything is often hard, if not impossible to do, regardless of whether licensing fees are rarely collected or not. Like many other image and video formats, Theora uses Chroma subsampling. Look up Ogg in Wiktionary, the free dictionary. ... Vorbis is an open source, lossy audio codec project headed by the Xiph. ... This article is about free software as defined by the sociopolitical free software movement; for information on software distributed without charge, see freeware. ... In digital image processing, chroma subsampling is the use of lower resolution for the colour (chroma) information in an image than for the brightness (intensity or luma) information. ...

VP3

VP3 was originally a proprietary video codec developed by On2 Technologies. It is approximately comparable in quality and bit rate to MPEG-1 video codecs. A video codec is a device or software module that enables video compression or decompression for digital video. ... On2 Technologies is the developer behind the VP5 and VP6 codecs powering the video part of the Chinese-developed competitor to DVD, the EVD (Enhanced Versatile Disc). ... In telecommunications and computing, bit rate (sometimes written bitrate) is the frequency at which bits are passing a given (physical or metaphorical) point. It is quantified using the bit per second (bit/s) unit. ... MPEG-1 defines a group of Audio and Video (AV) coding and compression standards agreed upon by MPEG (Moving Picture Experts Group). ...

In September, 2001 it was donated to the public as open source, and On2 disclaimed all rights to it, including their patents on the technology. In 2002, On2 entered into an agreement with the Xiph.Org Foundation to make VP3 the basis of a new, free video codec, Ogg Theora. It can be operated alongside Ogg Vorbis to provide a set of open source multimedia codecs that are intended to be free of patent licensing restrictions and royalty fees. Theora is currently still in alpha stage. However, the bitstream format was frozen with alpha 3, therefore video encoded with the current codec will be playable by future versions of the Theora decoder. 2001 (MMI) was a common year starting on Monday of the Gregorian calendar. ... Open source refers to projects that are open to the public and which draw on other projects that are freely available to the general public. ... A patent is a set of exclusive rights granted by a state to a patentee (the inventor or assignee) for a fixed period of time in exchange for the regulated, public disclosure of certain details of a device, method, process or composition of matter (substance) (known as an invention) which... For album titles with the same name, see 2002 (album). ... The Xiph. ... Look up Ogg in Wiktionary, the free dictionary. ... Vorbis is an open source, lossy audio codec project headed by the Xiph. ... A Codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. ... In software engineering, development stage terminology expresses how far through the development sequence things have progressed and how much further development a product may require. ...

Encoding Theora videos

The libtheora library contains the reference implementations of both the Theora encoder and decoder. libtheora is still under development by the Xiph.Org Foundation, which has made seven alpha releases thus far. The library is released under the terms of a BSD-style license. The Xiph. ... Software development stages In computer programming, development stage terminology expresses how the development of a piece of software has progressed and how much further development it may require. ... The BSD daemon BSD licenses represent a family of permissive free software licenses. ...

As of 2006, Xiph.Org has not developed any stand-alone programs to encode video in Theora, but there are several third-party programs that support encoding through libtheora:

• ffmpeg2theora uses FFmpeg to decode video and libtheora to encode it. This is currently the most functional Theora encoder, and can be used for both creating stand-alone video files and to produce streaming video.
• VLC is able to encode Theora video, from any of the video sources it supports, and also stream it.
• The open-source OggConvert [1] utility can convert virtually all common media formats to Theora.
• The open-source 'Video DJ' program FreeJ can encode and stream ogg/theora. Video comes from one or more different video or image files/sources while audio is encoded from the soundcard.
• The GNOME video editor Diva encodes to Ogg Theora.
• The open-source Video Editing program LiVES can also encode to ogg theora at different quality settings.
• There is also currently a beta-version of Thoggen [2] for Linux, a GTK+ and GStreamer based DVD-backup utility, which encodes to Ogg (Vorbis audio, Theora video).
• KungFu DVD Ripper [3]

Also, several media frameworks have support for Theora. FFmpeg is a collection of free software that can record, convert and stream digital audio and video. ... The VLC media player is a free software media player, distributed under the GNU General Public License. ... FreeJ is an instrument for realtime video manipulation where various input layers combined with live effects. ... This article or section does not adequately cite its references or sources. ... LiVES (LiVES is a Video Editing System) is a video editing program and VJ tool, released under GNU General Public License. ... Thoggen is a DVD backup utility (DVD ripper) for Linux within the GNOME project. ... GStreamer is a multimedia framework written in the C programming language with the type system based on GObject. ... Look up Ogg in Wiktionary, the free dictionary. ... Vorbis is an open source, lossy audio codec project headed by the Xiph. ...

• The open-source ffdshow audio/video decoder is capable of encoding Theora videos using its Video for Windows (VFW) multi-codec interface within popular AVI editing programs such as VirtualDub. It supports both encoding and decoding Theora video streams and uses Theora's alpha 4 libraries. However, many of the more refined features of Theora aren't available to the user in ffdshow's interface.
• The GStreamer framework has support for Theora.

ffdshow is an open source decoder (and encoder) mainly used for the fast and high-quality decoding of video in the MPEG-4 ASP (e. ... Video for Windows was a multimedia technology developed by Microsoft that allowed Microsoft Windows to play digital video. ... VirtualDub is an open source video capture and linear processing tool for Microsoft Windows. ... GStreamer is a multimedia framework written in the C programming language with the type system based on GObject. ...

Editing Theora videos

CVS versions of the Cinelerra non-linear video editing system support Theora, as of August 2005. The Concurrent Versions System (CVS), also known as the Concurrent Versioning System is an open-source version control system invented and developed by Dick Grune in the 1980s. ... Cinelerra is a free non-linear video editing system for the GNU/Linux operating system. ... Note: Please see National Latin Examination for the standardized test that is also abbreviated NLE. A non-linear editing system (abbreviated NLE) is a video editing or audio editing system that can perform random access on the source material. ...

Playing Theora videos

If you want to find videos to test out your new theora-enabled player, see the Theora test suite.

List of Theora video players

See also Wikipedia:Media help (Ogg)

• Cortado, a Java based applet
  • Itheora, a PHP wrapper for Cortado
• FFmpeg (own implementation)
• illiminable Ogg Directshow Filters for Speex, Vorbis, Theora and FLAC enable DirectShow-based players, such as Media Player Classic, Windows Media Player, and Winamp (when properly configured) to play Theora.
• RadLight Theora DirectShow filter from the RadLight Open Source project enables Microsoft Windows Media Player to play theora videos.
• MPlayer
• RealPlayer (requires these codecs for a non-helix player based RealPlayer)
• Helix Player
• VLC (native support)
• xine and all libxine-based players like Kaffeine
• Totem
• QuickTime 7 (Requires official (and experimental) components for playback on Windows and Macintosh systems)
• Visonair.tv Player
• The KMPlayer
• Democracy Player

Cortado is a streaming Java applet for Ogg formats, released under GPL. Itheora http://www. ... Java is an object-oriented applications programming language developed by Sun Microsystems in the early 1990s. ... An applet is a software component that runs in the context of another program, for example a web browser. ... ITheora is a PHP wrapper for Cortado, a Java-based means of embedding Theora-encoded videos and video streams into webpages. ... FFmpeg is a collection of free software that can record, convert and stream digital audio and video. ... Logo of the DirectX Media SDK - the first time DirectShow was distributed under its current name. ... Media Player Classic (MPC) is a compact free software media player for Microsoft Windows. ... Windows Media Player (WMP) is a digital media player and media library application developed by Microsoft that is used for playing audio, video and images on personal computers running the Microsoft Windows operating system, as well as on Pocket PC and Windows Mobile-based devices. ... Winamp is a proprietary media player written by Nullsoft, a subsidiary of Time Warner. ... This article is about the open source media player. ... RealPlayer is a cross-platform media player by RealNetworks that plays a number of multimedia formats including MP3, MPEG-4, QuickTime, Windows Media and multiple versions of proprietary RealAudio and RealVideo codecs. ... Helix is an open multi-format digital media framework. ... The VLC media player is a free software media player, distributed under the GNU General Public License. ... The correct title of this article is . ... Kaffeine is a full featured media player for UNIX based machines running the KDE (K Desktop Environment). ... Totem Movie Player is a media player (audio and video) for the GNOME personal computer desktop environment which runs on Linux, Solaris, BSD and other UNIX and UNIX-like systems. ... QuickTime is a multimedia framework developed by Apple Inc. ... plays internet streams in Ogg/Vorbis/Theora format. ... The KMPlayer (not to be confused with KMPlayer) is a video and audio player for Windows which can play a large number of formats such as VCD, DVD, AVI, MPEG-1/2/4, WMV, RealMedia, and QuickTime among others. ... Democracy Players (also known as Democracy and DTV) is an Internet television program developed by the Participatory Culture Foundation (PCF). ...

Streaming Theora

The following streaming media servers are capable of streaming Theora video:

• VLC
• Icecast
• Flumotion
• FreeCast, a Java peer-to-peer streaming solution

The VLC media player is a free software media player, distributed under the GNU General Public License. ... Icecast is a FOSS streaming media project maintained by the Xiph. ... FreeCast Manager, listeners website and FreeCast client FreeCast is a free software application which allows peer-to-peer streaming, sometimes called peercasting. ... Java is an object-oriented applications programming language developed by Sun Microsystems in the early 1990s. ...

See also

Free software Portal

• Video editing software
• Dirac
• Comparison of video codecs

Image File history File links Floss_draft. ... It has been suggested that Movie Making Software be merged into this article or section. ... Dirac is a prototype algorithm for the encoding and decoding (see codec) of raw video. ... This is a comparison of video codecs. ...

External links

• AMPE — An Open Source (LGPL) .Net library for playing Theora video.
• Theora.org
• Theora I Specification
• Building an Ogg Theora camera using an FPGA and embedded Linux
• ffmpeg2theora
• v2vwiki's list of Theora players
• List of Theora videos — downloadable videos encoded with Theora
• Why Ogg Theora Matters for Internet TV
• Ogg Theora on Danish Public TV? — DR (Danmarks Radio - Denmark's primary public TV station) is currently evaluating Ogg Theora as an alternative to Windows Media (Danish)