Theora

For the genus of clams, see Theora (bivalve).

Theora
Filename extension
.ogv, .ogg
Internet media type
video/ogg
Developed byXiph.org
Initial release1 June 2004 (2004-06-01)[1]
Latest release
Theora I
16 March 2011[2]
Type of formatVideo coding format
Contained byOgg, Matroska
Extended fromVP3
StandardSpecification
Open format?Yes[3]
Free format?Yes[4]
Websitetheora.org
libtheora
Developer(s)Xiph.org
Initial release3 November 2008 (2008-11-03) (1.0)
Stable release
1.1.1 / 1 October 2009; 15 years ago (2009-10-01)[5]
Preview release
1.2.0 Alpha 1 / 24 September 2010; 14 years ago (2010-09-24)[6]
Written inC
Operating systemUnix-like (incl Linux, Mac OS X), Windows
TypeVideo codec, reference implementation
License3-clause BSD
Websitewww.theora.org

Theora is a free lossy video compression format.[7] It was developed by the Xiph.Org Foundation and distributed without licensing fees alongside their other free and open media projects, including the Vorbis audio format and the Ogg container.

The libtheora video codec is the reference implementation of the Theora video compression format developed by the Xiph.Org Foundation.[8][9]

Theora was derived from the formerly proprietary VP3 codec, released into the public domain by On2 Technologies. It is broadly comparable in design and bitrate efficiency to MPEG-4 Part 2, early versions of Windows Media Video, and RealVideo while it lacked some of the features present in some of these other codecs. It is comparable in open standards philosophy to the BBC's Dirac codec.

Theora was named after Theora Jones, Edison Carter's Controller on the Max Headroom television program.[10]

  1. ^ Giles, Ralph (1 June 2004). "Theora I bitstream freeze". theora-dev (Mailing list). Retrieved 25 September 2009.
  2. ^ "Theora Specification" (PDF). Xiph.Org Foundation. 16 March 2011. Retrieved 31 January 2012.
  3. ^ "PlayOgg! – FSF – Free Software Foundation". 17 March 2010. Retrieved 1 October 2013.
  4. ^ "Theora FAQ". Xiph.org. 2016. Archived from the original on 26 September 2020. Retrieved 1 December 2021.
  5. ^ "Theora 1.1.1 release". Xiph.Org Foundation. Retrieved 6 October 2009.
  6. ^ "libtheora 1.2.0alpha1 release". Xiph.Org Foundation. September 2010. Retrieved 10 October 2010.
  7. ^ Theora.
  8. ^ Xiph.Org Foundation. "libtheora Documentation 1.1.0". Xiph.Org Foundation. Retrieved 25 September 2009.
  9. ^ ohloh. "libtheora". ohloh. Archived from the original on 10 October 2010. Retrieved 25 September 2009.
  10. ^ "Theora FAQ". Xiph.Org Foundation. Retrieved 6 August 2009.