Assembly Real-time Realization Of G.729 Speech Compressing Coder Based On DSP Of TI

As a special element to process digital signal, The basic theory of DSP was studies internationally in 1960s, and the first general DSP chip, with a hard multiplier, was put out in 1980s. With the great progresses and a series of break-through in VLSI technologies, integrated DSPs came out soon after. Integrated DSPs possess many advantages, such as compactness, low power cost, and high working speed and so on which are mostly suitable in speech signal compressing. Present DSPs are getting more and more attentions in the information field, due to its powerful signal processing ability, becoming a hot-point technique in communication and other relating signal processing areas.Among various DSP products, DSP chips, produced by the America TI, hold more than 50% percent in the whole DSP market, coming out first due to the excellent qualities. Therefore, most works in the application of DSP in many technical areas are carried out around TI DSP.TMS320VC5402's software development tool provides high-level language compiler, the C language compiler, which has the difficulty in real-time signal processing in the DSK (DSP start kit) board. The G.729 speech-compressing algorithm, written in C language, produces a huge amount of program codes, which cannot be stored in the chip-memory of DSP because of its 16K storing space. Therefore, G.729 speech-compressing algorithm written in C language is faced with the problems of low processing speed, and synthesis (or real time). The main goal of this paper is to accomplish G.729 speech signal compressing algorithm programmed in C54X general assembly language, and to overcome the problems above. After about two years' insisting and hard working, this goal set at the beginning has become true. The developed C54X general assembly program for G.729 speech signal compressing algorithm has passed the tracking with more than 3,000 unitary standard measuring vectors. G.729 speech signal compressing compiler using C54X general assembly program has been accomplished real-timely, and undistorted rebuilt speech signals have been obtained. The results of this paper indicate that G.729 speech signal compressing coding programmed in assembly language can overcome the real-time problem merged in C language program.This paper consists of five parts. The first chapter introduces the state-of-the-art of DSP and speech compressing technique. In the second chapter, DSP's characteristics, performance index, development tools of software, repertoire and hardware structure go into particulars. The third part in this paper gives G.729 compressing algorithm. The kernel of this paper occurs in the fourth chapter, namely the realization of G.729 speech signal coder. The last part of this paper draws the conclusion and conceives this task's betterments.