摘要
ITU G728 标准是国际电信联盟于1992 年推出的一种比特率为16 Kb/s低延时CELP类型语音编解码器。本文首先对G728 编解码算法和定点数字信号处理芯片TMS320C54X作了简单介绍。由于G728 标准是一种低延时语音编码标准,因此计算复杂度高,在实时实现中需要作特别处理。本文着重介绍了这种低延时CELP(LDCELP)算法在TMS320C54X上实现的软、硬件设计和在定点DSP芯片上实现此算法的一些关键技术,并给出了实际试验结果。实际结果表明,一路全双工实现所需计算量为33 MIPS(兆整点指令每秒),1.7 K字程序空间和2.3 K 字数据空间。
ITU G 728 recommendation is a scheme for coding speech at 16 Kbit/s using low delay code excited linear prediction (LD CELP). In this paper, the algorithms of LD CELP and TMS320C54X fix point DSP chip are presented briefly. As the G 728 recommendation is a low delay speech codec, its complexity is very high. So how to reduce the complexity is a key issue during real time implementation. This paper introduces some key techniques for the real time implementation of LD CELP based on TMS320C54l chip in detail. As a result, one full duplex implementation needs 33 MIPS, 1.7 K words of program memory, and 2.3 K words of data memory.
出处
《数据采集与处理》
CSCD
1999年第3期343-346,共4页
Journal of Data Acquisition and Processing