Context adaptive binary arithmetic decoding on transport triggered architecture

Video coding standards, such as MPEG-4, H.264, and VC1, define hybrid transform based block motion compensated techniques that employ almost the same coding tools. This observation has been a foundation for defining the MPEG Reconfigurable Multimedia Coding framework that targets to facilitate multi-format codec design. The idea is to send a description of the codec with the bit stream, and to reconfigure the coding tools accordingly on-the-fly. This kind of approach favors software solutions, and is a substantial challenge for the implementers of mobile multimedia devices that aim at high energy efficiency. In particularly as high definition formats are about to be required from mobile multimedia devices, variable length decoders are becoming a serious bottleneck. Even at current moderate mobile video bitrates software based variable length decoders swallow a major portion of the resources of a mobile processor. In this paper we present a Transport Triggered Architecture (TTA) based programmable implementation for Context Adaptive Binary Arithmetic de-Coding (CABAC) that is used e.g in the main profile of H.264 and in JPEG2000. The solution can be used even for other variable length codes.