The VC-2 Low Delay Video Codec

Much research has been focused on the development of codecs for distribution to end users via broadcasts, optical disks, the Internet and mobiles. But codecs are also required during the production of television and movies. This paper describes the VC-2 Low Delay codec (VC-2 LD), developed in BBC R&D and standardised by the Society of Motion Picture and Television Engineers (SMPTE). It describes the design requirements for a production, or “intermediate” codec. It provides an overview of the algorithms, and the innovative features, that are used in VC-2 LD. And it discusses the system features that make VC-2 LD useful in a variety of applications. Experimental results are provided for the performance of VC-2 LD. These results demonstrate that, in addition to its other advantages (low complexity and ultra low latency) at medium and high bit rates VC 2 LD provides performance comparable to or better than well known codes such as Apple ProRes or DNxHD. Additional key words: discrete wavelet transform, lifting, integer transform, edge extension, quantisation matrix, interleaved exp-Golomb, texture masking, rate control, slices, early termination, ultra low latency, low complexity, concatenated coding, royalty free, Dirac Pro.