基于威焱831平台的H.264视频解码优化

H.264 video decoder optimization based on Weiyan 831 platform

为提高威焱831平台的多媒体处理能力,解决H.264解码器解码效率低的问题,在提出SIMD指令级优化方法的同时,提出一种面向帧拷贝的优化方法。通过分析开源软件FFmpeg中H.264解码器的并行化特性,使用威焱平台性能分析工具解析影响视频解码性能的热点函数。采用手工嵌入SIMD汇编指令的方式对关键模块热点函数进行优化,通过FFmpeg源码编译过程链接汇编实现的内存操作函数memcpy提升内存拷贝速度。实验结果表明,威焱831平台视频解码的平均性能提高26%,推动了威焱831处理器在多媒体应用领域的发展。

In order to improve the capability of multimedia processing and the decoding efficiency of H.264 decoder on Weiyan 831,an optimization method for frame copy is proposed while the SIMD instruction level optimization method is proposed.By analyzing the parallel characters of the H.264 decoder in the open source Ffmpeg,the performance analysis tool on Weiyan platform is used to analyze the hot functions that influence the video decoding.The key module hotspot functions are optimized by manually embedding SIMD assembly instructions,and the memory operation function memcpy is implemented by means of FFmpeg source code compilation linked to assembly,so as to improve memory copying speed.The experimental results show that the average video decoding performance on Weiyan 831 platform is improved by up 26%,which can effectively promote the development of Weiyan 831 processors in multimedia applications.