基于高速DSP的H.264视频编码器的实现和优化

H.264是由ITU-T和ISO联合制定的新一代视频编码标准,具有低码率、高质量的特点。TMS320C64x是美国德州仪器公司目前性能最高的定点数字信号处理芯片。该文在介绍H.264编码器新的技术特点的基础上,探讨了基于TMS320 C6416 DSP平台的H.264编码器的设计和实现。文章讨论了该编码器的硬件平台的结构特点及多种代码移植和优化方法,着重介绍了如何在C64x扩展指令集的基础上对程序的关键耗时模块进行优化,以及在实现过程中如何根据程序流和数据流的运转特征,使用EDMA进行资源调度,合理地分配和利用DSP有限的存储资源。试验结果表明,通过有效的优化手段,该编码器在保持较高的图像质量和压缩效率的同时,在QCIF格式下达到了实时编码效果,可以适用于多种实时应用场合。

Realization and Optimization of H.264 Encoder Based on High-Speed DSP Platform

H.264 is a new generation of video coding standard.Jointly established by ITU-T and ISO,the standard is of character- istics of low code rate and high quality.TMS320C64x is the highest-performance fixed-point digital signal processor family made by TI Corporation.This paper first introduces new technical features of the H.264 video encoder,and then discusses the design and implemen- tation of H.264 encoder based on TMS320C6416 DSP.The structure and developing platform of hardware,the procedure of code trans- plant and many optimizing methods applied are investigated.The optimization of the critical time consuming modules based on the ex- tended instruction set of C64x,the scheduling of data rolled-in and rolled-out by EDMA based on the running rule of the program and da- ta stream,and the utilization of the limited in-chip storage resources are studied in detail to improve the coding efficiency.The experi- ment results have shown that the proposed H.264 encoder can encode QCIF images sequences in real-time speed with high image quality and compression efficiency,thus can be employed in many real-time applications.