The Research And Implementation On DSP Of The Low Code Rate Speech Codec Algorithm

Language communication is the most fundamental information exchange method in life.in bank system, public security system, air traffic administration, fly recorder, call for centre, rail transport and so on ,much speech conversation must be recorded for the purpose of check, then corresponding equipment is need to store and replay speech information.The G.729 speech coding and encoding algorithm chosen by the paper in the designing of the train monitors speech recorder system is current an newer international speech compresses standard, is able to satisfy system design demand. In March 1996, ITU-T (Telecommunication standardization sector of International Telecommunication Union) presented the Recommendation G.729, that is the CS-ACELP speech coding algorithm. The Recommendation G.729 is a new algorithm and has good performance. It has been widely used in the field of IP phone, multimedia communication, satellite communication, speech storing, digital video monitor systems and so on.In this paper, based on grasping the principle of G.729, hardware design and several software optimization techniques are presented for efficient implementation of G.729 standard. Firstly, after studied and grasped the relevance theory of speech coding and encoding, the G.729 algorithm have been researched deeply and understanding thoroughly in this paper. Secondly, according to the requirement of memory and running speed for G.729 implementation, the hardware platform is designed. After the analysis of G.729, several optimization techniques for efficient implementation of G.729are presented on the level of C language, compiler and algorithm. Lastly the real-time implementation of the codec on the DSP and emulation investigating on computer is completed, the quality of the synthesis speech is appraised by subjective listening and objective computing.