name: Libtheora
description: Theora Video Compression Codec
version: 1.2.0
date: 20250512-15.56
author: Xiph.Org Foundation
submitter: Michael Trebilcock
url: https://www.theora.org/
category: development/library/graphics
replaces: development/library/graphics/libtheora.lha
license: Other
minosversion: 4.1
distribute: yes
fileid: 13339
hend:


# Xiph.org Foundation's libtheora

### What is Theora?

Theora was Xiph.Org's first publicly released video codec, intended
for use within the Foundation's Ogg multimedia streaming system.
Theora is derived directly from On2's VP3 codec, adds new features
while allowing it a longer useful lifetime.

The 1.0 release decoder supported all the new features, but the
encoder is nearly identical to the VP3 code.

The 1.1 release, codenamed Thusnelda, featured a completely rewritten
encoder, offering better performance and compression, and making more
complete use of the format's feature set.

The 1.2 release, codenamed Ptalarbvorm, features significant
additional improvements in compression and performance. Files produced
by newer encoders can be decoded by earlier releases.

### Where is Theora?

Theora's main site is https://www.theora.org. Releases of Theora
and related libraries can be found on the
[download page](https://www.theora.org/downloads/) or the
[main Xiph.Org site](https://xiph.org/downloads/).

Development source is kept at https://gitlab.xiph.org/xiph/theora