Dirac is a video codec that provides general-purpose video compression and decompression tools comparable with state-of-the-art systems. Dirac is a format and a compression technology, not a specific codec. The most important part of the Dirac project is the specification, which can be found here.

The purpose of the Dirac codebase has changed over time. It is no longer intended as the basis of a real-time practical implementation: for that you want Schrodinger.

Instead the Dirac project provides reference code for Dirac. This is available for distribution under the MPL version 1.1 software license (and can be relicensed under LGPL and GPLv2). This is not meant to be used in real systems, but to show the capabilities of Dirac. We are currently developing a full conformance test suite against which other implementations can be tested.

Schrodinger is a high-speed Dirac codec being developed by Fluendo in partnership with the BBC. The main developer is David Schleef, who developed the liboil optimisation library which is heavily used in the project.

Schro had just reached reached version 1.0: it's very fast and its compression performance is beginning to get close to the Dirac implementation. Schro is available as a set of libraries and as a GStreamer plugin, under any of the GPLv2, LGPL, MIT or MPL licences.

The Sourceforge project page gives access to the discussion forums, which are the main way to talk to Dirac developers. You can also browse the CVS repository. There's detailed documentation for the software API for the reference code and the algorithm also.

If you have a query or want to get involved in developing Dirac, please get in touch.

Parts of this site make use of MathML and SVG. Please read the browser compatibility notes before reading the Dirac documentation - especially if you have Internet Explorer.

Original website design created by Chris Bowley with updates and amendments by Pete Shelswell.