2 This
document is the specification of the Dirac video decoder and stream syntax.
4 Dirac is a royalty-free video compression system developed by the BBC
5 utilising wavelet transforms and motion
6 compensation. It is designed to be simple, flexible, yet highly effective.
7 It can operate across a wide range of resolutions and
8 application domains, including: internet and mobile streaming, delivery of
9 standard-definition and high-definition
10 television, digital television and cinema production and distribution,
11 and low-power devices and embedded applications.
13 The system offers several key features:
15 \item lossy and lossless coding using a common tool set
16 \item intra-coded modes for professional production applications
17 \item a special low delay mode for link adaption applications, such as the carriage of HDTV
18 over SDTV infrastructure
19 \item motion-compensated (`long-GOP') modes for distribution applications
20 \item gradual quality reduction with increasing compression