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Theora is a codec video free and without patents promoted by the foundation Xiph.org. It is one of the components of their project of Format of Encapsulation Ogg, the purpose of which is to create a whole of Open standards concerning the multi-media signal processing (its, video). Theora provides it video.

Theora uses a license of the type BSD and bases on free codec VP3 of On2 Technologies.

Theora is a codec which enters in competition with codecs such as MPEG-4 (example: the XviD and DivX), Windows Media Video or RealVideo.

To note that contrary to the codec XviD, the codec Theora is subjected to no Brevet pertaining to MPEG-4. Theora is subjected all the same to Brevet S pertaining to On2 Technologies but On2 gave the irrevocable right to use the patents in question without any restriction.

This gives the right to all to just like use Theora at not-commercial ends with business ends without paying royalty with the consortium MPEG, which is the case of the XviD neither of the DivX nor of any other video codec of this quality.

Etymology

The name Theora is based, like all those of Xiph.org, on that of a character of fiction. It is here about Theora Jones, character of the series television max Headroom.

History

• September 2001: The codec VP3 is released

• Mars 2002: First advertisement by Xiph.org of the intention to create a new codec based on VP3
• September 2002: Version Alpha one of Theora
• December 2002: Version Alpha two
• June 2003: first implementation of reference
• January 2004: integration with Helix Player
• Mars 2004: Version Alpha three
• June 2004: the Theora format is declared final. It will not change any more and all the flows encodés with the later versions will be retro-compatible.
• December 2004: Version Alpha four
• August 2005: Version Alpha five
• May 2006: Version Alpha six
• June 2006: Version Alpha seven: MX activated by defect.

Software using Theora

Theora is not very widespread yet, unlike Vorbis.

PeerTV proposes chains in Ogg Theora, via the network Peercast.

Video players Free S

• VLC

• Helix Player
• Xine and MPlayer

Plugins for not-free video players

• Real Player developed a free plugin in partnership with Xiph.

• For Windows Media Player like any reader using DirectShow using filters * For QuickTime on Windows/Mac OSX like any reader using QuickTime:

Software encoding  :

• will ffmpeg2theora for GNU/Linux and Windows Transcode majority of the video files in Theora.
• encoder_example provided with the sources of will theora allows encoder will theora some starting from a video file YUV and of an audio file Wav E, functions on all the platforms supported by Theora.
• Katiuska is an graphical interface of will ffmpeg2theora and encoder_example for GNU/Linux. Katiuska allows also Ripper DVD the Theora format using mplayer. Katiuska is an application KDE using Kommander.
• Thoggen is an interface of Gstreamer allowing Ripper DVD. Thoggen is an application GNOME.
• ffmpegX is an graphical interface for will ffmpeg2theora like ffmpeg and Mencoder, which functions under Mac OS X (Panther or later advised).
• VLC is capable of encoder in Theora via small Fichier Assitant de Diffusion.

Free software of Streaming Theora

• PeerCast