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<h1>Theora video compression</h1>
<p>
Theora is a free and open video compression format from the
<span class="xiph">Xiph.org Foundation</span>. Like all our
multimedia technology it can be used to distribute film and
video online and on disc without the licensing and royalty
fees or vendor lock-in associated with other formats.
</p>
<p>
Theora scales from postage stamp to HD resolution and
beyond, and is considered particularly competitive at low
bitrates. It is in the same class as MPEG-4/DiVX, and like
the <a href="http://xiph.org/vorbis/">Vorbis audio codec</a>
it has lots of room for improvement and encoder technology
develops.
</p>
<p>
The bitstream format for Theora I was frozen Thursday, 2004
July 1. All bitstreams encoded since will remain compatible
with future releases.
</p>
<a name="source"><h2>Source</h2></a>
<ul>
<li>The <strong>libtheora</strong> reference implementation provides
the standard encoder and decoder under a BSD license.
[<a href="http://downloads.xiph.org/releases/theora/libtheora-1.0.tar.gz">libtheora-1.0</a>]
[<a href="https://git.xiph.org/?p=theora.git">Git master</a>]
</li>
</ul>
<p>Both of implementations depend on the following libraries...</p>
<ul>
<li><a href="http://downloads.xiph.org/releases/ogg/libogg-1.3.4.tar.gz">libogg-1.3.4</a></li>
<li><a href="http://downloads.xiph.org/releases/vorbis/libvorbis-1.3.6.tar.gz">libvorbis-1.3.6</a></li>
<li><a href="http://www.libsdl.org/">libSDL 1.2</a> or later for the playback example</li>
</ul>
<a name="documentation"><h2>Documentation</h2></a>
<ul>
<li><a href="faq/">Frequently Asked Questions</a></li>
<li><a href="doc/Theora.pdf">Theora Format Specification</a></li>
<li><a href="doc/libtheora-1.0/">libtheora API reference</a></li>
</ul>
<h2>Binaries</h2>
<p>Downloads to help you play or encode Ogg Theora files.</p>
<ul>
<li><a href="http://www.v2v.cc/~j/ffmpeg2theora/">ffmpeg2theora</a></li> command line encoder
<li><a href="http://videolan.org/">VLC player</a></li>
<li><a href="https://player.helixcommunity.org/2005/downloads/">Helix Player</a></li>
<li><a href="http://www.illiminable.com/ogg/">Windows Media plugins</a></li>
<li><a href="http://xiph.org/quicktime/download.html">Apple Quicktime</a></li>
</ul>
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