An In/Post-Loop Deblocking Filter With Hybrid Filtering Schedule

In this paper, we propose a high-throughput deblocking filter to perform the in-loop or post-loop filtering process for different standard requirements. The performance improvement is very mild if we replace a post-loop filter with an in-loop filter. To alleviate this problem, we derive an integration-oriented algorithm that can be reconfigured as the in-loop or post-loop filter. Moreover, we develop a hybrid filtering schedule to reach a lower bound of processing cycles. In particular, we reschedule the filtering order and reuse the intermediate pixels when the deblocking filter switches the filtered edges from vertical to horizontal direction. Finally, a 0.18-mum CMOS design that performs the in/post-loop filter with the hybrid filtering schedule is implemented. The synthesized gate counts are 21.1 K which is reduced to 70% of preliminary design that performs the in-loop or post-loop filter separately. Moreover, it achieves 4times10⁵ macroblock/s of throughput rate at a 100-MHz clock rate.