Real-time implementation of G.723.1A/G.729AB on a RISC processor for personal IP telephony devices

This paper describes implementation of international standard speech coders for IP telephony using an ARM processor. To implement the low bit-rate speech coders on real-time, we utilize compiler option, intrinsic functions, C code optimization and fast algorithms. Finally we applied optimized software codecs to IP phones and measured CPU usages of the coders. Experimental results showed that the optimised codecs can perform encoding and decoding simultaneously on real-time using a single ARM926EJ-S.