ITU-TG.729a语音编解码器的实时实现

Real-Time Implementation of ITU-TG.729a Speech Codec

G.72 9a是 ITU- T推出的用于 PSTN的第四代语音编码标准 ,采用了共轭结构 -算术码本激励线性预测编码 (CS- ACEL P)算法 ,其码率为 8Kbps。本文在对 G.72 9a的编解码算法作出扼要介绍后 ,就如何在定点 DSP芯片 TMS32 0 C5 41上实时实现该编解码算法做出了具体讨论 ,包括系统的软硬件设计及关键技术。随后文中给出了详细的实验结果以供分析。根据测试结果 ,最后得出结论 :在′C5 41上实现一路全双工 G.72 9a编解码器需程序空间 7.2 3K字、数据空间 6 .7K字 ,其算法复杂度最大为 15 .5

G.729a is the fourth generation of speech compression coding standard used on PSTN issued by ITU T. It is used for coding speech at 8 Kbps by conjugate structure algebraic code excited linear prediction (CS ACELP) scheme. This paper firstly introduces the coding and decoding algorithm of the G.729a speech codec, then concretely discusses its real time implementation on a fixed point DSP chip TMS320C541, including the system design of hardware and software as well as the key techniques. Subsequently, the detailed experimental results of the implementation are given for succeeding analysis. According to the test, final conclusion can be reached: one full duplex implementation of G.729a speech codec on TMS320C541 needs 7.23 K word of program memory, 6.7 K word of data memory and 15.5 MIPS (on worst occasion).