【作者】 权元文；

【导师】 廉保旺；

【作者基本信息】 西北工业大学 ， 通信与信息系统， 2005， 硕士

【摘要】 语音通信是现代多媒体通信中一个重要的组成部分,语音压缩又是实现低速率语音通信的关键技术。ITU-TG.729协议是基于共轭结构-代数码激励线性预测(CS-ACELP)算法的语音压缩编码技术。该算法使用混合编码方法,采用了比较先进的几种语音分析技术,其编码速率达到8kbit/s,合成语音质量的主观评价MOS分达4. 0,是编码速率和合成语音质量综合效率最优的压缩算法之一。本文首先对CS-ACELP算法所采用的主要技术进行了分析,对G.729协议的算法结构及原理作了介绍,详细说明了基于高性能的DSP TMS320VC5402的语音信号压缩编码的具体实现方法,并提出了算法实现的代码优化方法。通过对优化后的程序进行测试验证,编解码结果正确,运算时延小于算法所要求的最小时延,基本实现了G.729协议在TMSVC5402上的实时化,表明本文研究的优化方法对算法的实现是有效的,为G.729协议在低价位、低功耗的DSP上的实用化提供了一个有益的借鉴。更多还原

【Abstract】 Speech communication is an important component of modern multimedia technology; speech compression is also the key technology to realize the low speed speech communication. ITU-T G.729 protocolis a kind of speech compression coding technology based on Conjugate Structure Algebraic Code Excited Linear Prediction (CS-ACELP) algorithm. Mixed coding and several advanced audio analysis technologies are used in this algorithm, which makes its coding speed to be 8kbit/s and MOS 4.0 of subjective evaluation. Several key technologies are analyzed in this thesis, then the algorithm structure and theory of G.729 protocol are discussed. Based on the TMS320VC5402 DSP, the scheme and implementation of this protocol are presented. The algorithm code is optimized and tested. The test about the optimized code shows that, the coding and decoding results are correct, computing delay is smaller that the required minimum delay time. The real-time implementation of G.729 on TMSVC5402 shows this optimizing method is practical, provides a good help for the application of G.729 on low price, low power consumption DSPs.更多还原