Implementation and Optimization of G.728 Speech Coder Based on TM1300

In this paper, a brief introduction to the algorithms of ITU G.728 and some main features about the fixed-point DSP chip TM1300 is firstly carried out. Subsequently, a project running on TM1300 for realtime speech sampling, speech encoding decoding and playing is designed according to the characteristic of the hardware structure. The emphatically key technologies and problem of the realtime implementation of the multichannel G.728 codec on fixed-point DSP chip are discussed. The optimization technical is given in detail to the G.728 encoding and decoding algorithms for this hardware and compile system. And in order to reduce the computational complexity, the best codebook index selector and pitch period selector module are improved. The test results are listed in the end.