Architecture design of H.264/AVC decoder with hybrid task pipelining for high definition videos
The most critical issue of an H.264/AVC decoder is the system architecture design with balanced pipelining schedules and proper degrees of parallelism. In this paper, a hybrid task pipelining scheme is first presented to greatly reduce the internal memory size and bandwidth. Block-level, macroblock-level, and macroblock/frame-level pipelining schedules are arranged for CAVLD/IQ/IT/INTRA/spl I.bar/PRED, INTER/spl I.bar/PRED, and DEBLOCK, respectively. Appropriate degrees of parallelism for each pipeline task are also proposed. Moreover, efficient modules are contributed. The CAVLD unit smoothly decodes the bitstream into symbols without bubble cycles. The INTER/spl I.bar/PRED unit highly exploits the data reuse between interpolation windows of neighboring blocks to save 60% of external memory bandwidth. The DEBLOCK unit doubles the processing capability of our previous work with only 35.3% of logic gate count overhead. The proposed baseline profile decoder architecture can support up to 2048/spl times/1024 30 fps videos with 217 K logic gates, 10 KB SRAMs, and 528.9 MB/s bus bandwidth when operating at 120 MHz.