基于DM642的X264程序结构级优化

The Structure-level Optimization of X264 Based on DM642

介绍了在TI公司TMS320 DM642硬件平台上实现H.264基本档次视频编码器时所进行的结构级优化,选取H.264三大开源代码之一的X264(代码版本为06-05-06)作为参考代码,在深入分析了基于PC的X264编码程序并将其成功移植到了DM642后,首先对代码进行了最初的简化,去掉了和平台无关以及和实现档次无关的冗余代码和数据结构,而后结合DM642的特点,以充分利用DM642片上资源为出发点,以提高DM642高速缓冲(CACHE)的命中率为目的,提出了一种结构级的优化策略,该策略从程序和数据两个方面对X264算法参考代码进行了结构级优化。实验结果表明,采取的优化策略对CACHE命中率和编码速率都有明显的提高。

This paper introduces the structure-level optimization when realizing the H.264 baseline encoder based on TMS320DM642 hardware plateform developed by TI company, selects the X264 （code edition： 06-05-06） which is one of the three open code complied with the H.264 standard as the reference code, and after analyzing the x264 encoding procedures based on PC thoroughly and transplanting it to the DM642, makes the original optimization for the code, deletes the redundant code and data structure that are independent of the implementation level, and connecting with the features of DM642, starting from the full use of the resources on DM642, and aiming at improving the CACHE hit rate, puts forward a kind of structure-level optimization strategy, which optimizes the structure of the reference code from both code and data. The experimental results show that the optimization strategy adopted can improve the CACHE hit rate and coding rate obviously.