Introduction

In January 2003, BBC R&D produced a prototype video coding algorithm, based on wavelet technology, which is different from that used in the main proprietary or standard video compression systems. Our algorithm gives at least two-fold reduction in bit rate over MPEG-2 for high definition video (e.g. 1920x1080 pixels), its original target application. It has been further developed to optimise it for internet streaming resolutions and seems broadly competitive with state of the art video codecs such as H264.

We have put a lot of work into Dirac.

The main specification is now written and available on SourceForge. Quality portable software to implement Dirac is being delivered both on the Dirac and Schrödinger ares of SourceForge. The intra-coding part has been proposed by the BBC to the SMPTE as an international standard, VC-2. In hardware, we are starting to see the first VC-2 products being designed, aimed at the professional market.

The algorithm has evolved, and is now available in useable code. This includes optimisation so that it can decode in real time. Standard definition formats should be decodable in real time on a normal (2006) laptop machine, with CPU capacity left to do real work. HD formats can be decoded on a top end machine. Java implementations are becoming available to allow other applications to be developed. Algorithmic enhancements are needed to improve the compression performance still further. The resulting codec needs to be integrated with other parts of a compression system, such as players, and interfaced using standard IO formats. We welcome help and support in creating an open and freely available compression system based on this technology.