A VLSI architecture for MPEG-4 core profile video codec with accelerated bitstream processing

A VLSI architecture with flexible, application-specific coprocessors for object based video encoding/decoding is presented. The architecture consists of a standard embedded RISC core, as well as coprocessor modules for macroblock algorithms, motion estimation and bitstream processing. Bitstream decoding involves strong data dependencies, which requires optimized logical partitioning. An optimized instruction set can speed up bitstream decoding by a factor of two. This architecture combines high performance of dedicated ASIC architectures with the flexibility of programmable processors. Dataflow. and memory access were optimized based on extensive studies of statistical complexity variations. Results on gate count and clock rate, required for realtime processing of MPEG-4 Core Profile video, are presented, as well as a comparison with software implementations on a standard RISC architecture.