Dirac video codec: introduction

Loo, Jonathan, Tun, Myo and Chang, Yoong Choon (2011) Dirac video codec: introduction. In: Streaming Media Architectures, Techniques, and Applications: Recent Advances. Zhu, Ce, Li, Yuenan and Niu, Xiamu, eds. IGI Global, Hershey, pp. 58-94. ISBN 9781616928315. [Book Section] (doi:10.4018/978-1-61692-831-5.ch004)


Dirac was started off by British Broadcasting Corp. (BBC) in 2003 as an experimental video coding system based on wavelet technology, which is different from that used in the main proprietary/standard video compression systems. Over the years, Dirac has grown out of its initial development and it is now on offer as an advanced royalty-free video coding system designed for a wide range of users, from delivering low-resolution web content to broadcasting high-definition (HD) and beyond, to near-lossless studio editing. The Dirac’s video coding architecture and algorithms are designed with the “keep it simple” mindset. In spite of that the Dirac seems to give a two-fold reduction in bitrate over MPEG-2 for HD video and broadly competitive with state-of-the-art video codecs. This chapter introduces the architecture of Dirac video encoder. The overall encoding structure is discussed followed by the detail description of motion estimation, Overlapped Block-based Motion Compensation (OBMC), Discrete Wavelet Transform (DWT), Rate Distortion Optimization (RDO) quantization and entropy coding. The Dirac’s bitstream syntax for compressed video data storage and streaming is described. Besides that, the coding performance of Dirac in terms of compression ratio, PSNR, SSIM and VQM in comparison with H.264 as a reference are discussed. Related issues such as transcoding and streaming over packat erasure channel are also discussed.

Item Type: Book Section
Research Areas: A. > School of Science and Technology > Computer Science > SensoLab group
A. > School of Science and Technology > Computer and Communications Engineering
Item ID: 7806
Useful Links:
Depositing User: Jonathan Loo
Date Deposited: 28 Apr 2011 12:19
Last Modified: 05 Jul 2017 13:10
URI: https://eprints.mdx.ac.uk/id/eprint/7806

Actions (login required)

View Item View Item


Activity Overview
6 month trend
6 month trend

Additional statistics are available via IRStats2.