A Three-Level Parallel High-Speed Low-Power Architecture for EBCOT of JPEG 2000
For JPEG 2000-based multimedia systems, embedded block coding with optimized truncation (EBCOT) tier-1 has become a bottleneck for the entire system. EBCOT tier-1 is full with bit operation, so hardware implementation is more efficient in both system throughput and power consumption. In this paper, a three-level parallel high-speed power-efficient architecture for EBCOT tier-1 is proposed. This architecture is divided into bit-plane coding (BC), arithmetic encoding (AE), and first-in first-out (FIFO) that connects BC with AE and balances the different throughput between them. To improve the system throughput, three levels of parallelism in BC are adopted: 1) the parallelism among bit planes; 2) the parallelism among three pass scans; and 3) the parallelism among coding bits. AE is implemented in four pipeline stages. To achieve power efficiency, several techniques are applied: in BC, simple control logics are added to reduce computation in BC; in FIFO, memory access is reduced since AE is fed with fixed values instead of reading from FIFO; in AE, simple control logics are added to reduce computation in AE and forwarding technique combined with clock gating is adopted to reduce switching activities in the last two pipeline stages. The proposed architecture can encode one code block with size NtimesN in only around (0.35~0.46)timesNtimesN clock cycles. Experimental results, with standard test image benchmarks, show that the proposed power reduction techniques keep the same system throughput and achieve about 27% improvement in the power consumption by comparison with the architecture without these techniques