VLSI architecture design of MPEG-4 shape coding

This paper presents an efficient VLSI architecture design of MPEG-4 shape coding, which is the key technology for supporting the content-based functionality of the MPEG-4 Video standard. The real-time constraint of MPEG-4 shape coding leads to a heavy computational bottleneck on today’s computer architectures. To overcome this problem, design analysis and optimization of MPEG-4 shape coding are addressed in this paper. By utilizing the RISC-based model, computational behaviors of the MPEG-4 shape coding tool are carefully examined and analyzed. The characteristic of a large amount of bit-level data processing and data transfer of MPEG-4 shape coding motivates us the optimization of bit-level data operations. Applying the data-flow optimization and data reuse techniques, bit-level computation-efficient architectures, such as data-dispatch-based binary-shaped motion estimation, the delay-line model, and configurable context-based arithmetic coding, are designed to accelerate bit-level processing. These hardware blocks are integrated and scheduled in a very efficient data flow to achieve real-time performance for MPEG-4 CPL2 specification at 23.5-MHz clock rate. The system architecture is implemented using Verilog HDL and synthesized with a 0.35m four-layer CMOS standard library.