Theora
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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., XviD and DivX), RealVideo, Windows Media Video, and similar lower-bitrate video compression schemes.
Theora is still in developmental stages with Xiph.org having made four alpha releases thus far.
- Alpha One was released on September 25, 2002
- Alpha Two was released half on December 16 and half on December 27, 2002
- Alpha Three was released on March 20, 2004
- Alpha Four was released on December 15, 2004
The first beta release Beta-1 is expected later in 2005. Theora is released under the terms of a BSD-style license.
While VP3 is patented technology, On2 has irrevocably given royalty-free license of the VP3 patents to all of humanity, enabling the public to utilize Theora and other VP3-derived codecs for any imaginable purpose.
In the Ogg multimedia framework, Theora provides a video layer, while Vorbis acts as the audio layer.
Theora is named for Theora Jones, Edison Carter's Controller on the Max Headroom television program.
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History
- September 6, 2001
- On2 releases the source code to their libraries for VP3 under the terms of the VP3.2 Public License.
- March 27, 2002
- On2's founder and CTO, Dan Miller, sends an email to vorbis-dev (http://www.xiph.org/archives/vorbis-dev/200203/0174.html) announcing On2's interest in collaborating with the Xiph.org Foundation and relicensing VP3 under the terms of the LGPL.
- June 24, 2002
- On2 and the Xiph.org Foundation announce their alliance to develop Ogg Theora: the integration of VP3 with the Ogg framework and Vorbis. See also On2's press release (http://on2.com/pressreleases.php3?qs1=vp3_combines_with_vorbis).
- September 25, 2002
- Theora Alpha One is released. See also On2's press release (http://on2.com/pressreleases.php3?qs1=On2_Xiph_Announce_Theora_Alpha).
- December 16 and December 27, 2002
- Theora Alpha Two is released in two stages.
- January 23, 2004
- Milestone 2 release of the RealNetworks Helix player includes preliminary support for Ogg Theora. Milestone 3, scheduled release in April 2004, is planned to provide complete support. See also the status at helixcommunity.org (https://xiph.helixcommunity.org/)
- May 10, 2004
- Theora/Vorbis plug-in version 0.2 for the Windows version of RealPlayer is released. Download it from helixcommunity.org (https://helixcommunity.org/project/showfiles.php?group_id=7).
- June 1, 2004
- The Theora bitstream format has been frozen. It has not been changed from Alpha Three. So it is guaranteed that all files encoded using Alpha Three (or any later version) will be supported by future decoders.
Playing Theora videos
- RealPlayer (requires these codecs (https://helixcommunity.org/project/showfiles.php?group_id=7))
- VLC (native support)
- Media Player Classic, Windows Media Player or other DirectShow based players (requires these codecs (http://www.illiminable.com/ogg/))
- Cortado (http://www.flumotion.net/news/) a Java based applet (http://www.fluendo.com/products.php?product=applet)
- MPlayer
- xine and all xinelib-based players like Kaffeine
- FreeCast (http://www.freecast.org) a Java peer-to-peer streaming solution
See also
External links
- Theora.org (http://www.theora.org/)
- Xiph.org Foundation (http://xiph.org/)
- On2 Technologies (http://on2.com/)
- VP3.com (http://vp3.com/)
- Building an Ogg Theora camera using an FPGA and embedded Linux (http://www.linuxdevices.com/articles/AT3888835064.html)de:Theora