Implementation of a multi-channel G.723.1 Annex A using a DSP

Abstract

This paper describes a multi-channel G.723.1 Annex A (G.723.1A) implementation focused on code optimization using a general purpose digital signal processor (DSP), TMS320C62x (C62x). To implement a multi-channel G.723.1A, complexity of the ITU-T C-code was analyzed. Then we sorted and optimized C functions in complexity order. In parallel with optimization, we verified the bit-exactness of the optimized code using the ITU-T test vectors. Using only internal memory, the optimized code can perform full-duplex 16 channel processing. In addition, we further increased the number of available channels per DSP using fast algorithms, referred to as bit-compatible optimization.