.ogv

Theora is the video format from the Xiph.org codecs. This is basically a open, patent-free format.
== How it works ==
It works very similar to MPEG-1,MPEG-2 and MPEG-4 using chroma subsampling, block based motion compensation and an 8 by 8 DCT block.
[[Category:File formats]
Category:Video codecs
Category:Xiph.org products