Real-time Implementation Of ITU G.729 Speech Codec Based On TMS320C64 DSP

Speech coding is to use signal processing methods to compress speech signals for efficient transmission in communication systems.In recent years,speech coding technology has made breakthroughs,and some speech coding algorithms have emerged to adapt to different application scenarios.In order to meet the voice transmission requirements for the VoIP and other networks,the ITU has proposed a speech coding standard based on conjugate structure-algebraic code excited linear prediction(CS-ACELP),namely ITU G.729 standard.The G.729 algorithm has low delay and high speech quality,but its computational complexity is too large to real-time processing.Therefore,how to efficiently implement speech codec on a given processor is an important problem in engineering practice.Based on the analysis of the basic principle of speech codec,the real-time implementation and optimization of ITU G.729 speech codec based on TMS320C64 DSP processor are studied in this thesis,and main work is listed as follows:.(1)On the basis of briefly discussing speech coding techniques such as speech signal generation model,linear prediction,vector quantization,and perceptual weighted filter,the principle and algorithm of G.729 speech codec are elaborated.Linear prediction analysis,Levinson-Durbin algorithm,line spectrum pair,open-loop pitch analysis,adaptive codebook and fixed codebook search,gain quantization and prediction,codebook decoding,long-term and short-term post-filters are also analyzed in detail.(2)On the TMS320C64 DSP,G.729 speech codec algorithms are realized.Firstly,based on Microsoft Visual Studio environment,G.729 speech codec standard is implemented in C language.Then,in order to improve computational efficiency and facilitate real-time processing,according to the structure characteristics of TMS320C64+ DSP,some code optimization techniques are given,and the performance of G.729 speech codec program is optimized based on TI CCS software development environment,which significantly improves the code execution efficiency.(3)The effectiveness of the optimized G.729 speech codec is verified by ITU test sequences and speech data,and its speech quality is verified objectively and subjectively.The experimental results show that the optimized G.729 speech codec can run in real-time and has good speech quality.