基于申威SIMD指令的H.264编码优化

H.264 encoding optimization based on SW SIMD instruction

国产化申威处理器出现较晚,其在多媒体领域中的性能还不突出,同时通用处理器中的单指令流多数据流(SIMD)因能有效提升并行处理能力而受到处理器厂商的青睐。为提高国产化自主平台申威架构的多媒体处理能力,结合申威架构Core3B体系的SIMD指令系统,提出一种基于申威架构的SIMD指令集H.264编码优化方法。结合申威处理器的并行结构特点,利用申威适配的Perf、Top指令等系统性能分析工具,采集两种主流视频分辨率下与编码性能强相关的高频热点函数,详细分析其程序并行化可行性,采用手工嵌入申威SIMD和访存扩展等汇编指令进行细粒度优化。实验结果表明,该方法在申威架构下的H.264平均编码性能提升了约30%。相应工作成果已推送到申威社区,增强了基于申威处理器的国产计算机在桌面多媒体应用领域的工作体验。

Domestic Shenwei processors emerged relatively late,and their performance in the multimedia field is not yet outstanding.At the same time,single instruction multiple data(SIMD) in general-purpose processors are favored by processor manufacturers for effectively improving parallel processing capabilities.In order to improve the multimedia processing capability of the domestic independent platform Shenwei architecture,a SIMD instruction set H.264 encoding optimization method based on the Shenwei architecture is proposed by combining with the SIMD instruction system of the Core3B system of the Shenwei architecture.Based on the parallel structure characteristics of the Shenwei processor,high-frequency hotspot functions strongly related to encoding performance under two mainstream video resolutions are collected by means of system performance analysis tools such as Perf and Top instructions adapted by Shenwei.The experimental results show that this method can improve the average encoding performance of H.264 under the Shenwei architecture by about 30%,and the corresponding work results have been pushed to the Shenwei community,enhancing the work experience of domestic computers based on Shenwei processors in the field of desktop multimedia applications.