g.729version1.5

G.729 Version 1.5 is a low-bit-rate speech codec developed by the International Telecommunication Union (ITU). It is designed to compress speech signals at very low bit rates, typically around 8 kbps, while maintaining acceptable voice quality.

Compared to the earlier G.729 version 1, version 1.5 introduces some improvements in the coding algorithm, which leads to a slightly better voice quality at the same bit rate. However, it is not backwards compatible with G.729 version 1, which means that devices supporting G.729 version 1.5 cannot communicate with devices using the earlier version.