Digital Cellular Telecommunications System (Phase 2+); Half Rate Speech; ANSI-C Code for the GSM Half Rate Speech Codec (GSM 06.06 Version 7.0.0 Release 1998)
The present document contains an electronic copy of the ANSI-C code for the GSM half rate codec. The ANSI-C code is necessary for a bit exact implementation of the half rate speech transcoder (GSM 06.20 [2])@ Voice Activity Detector (GSM 06.42 [6])@ comfort noise (GSM 06.22 [4])@ Discontinuous Transmission (GSM 06.41 [5]) and example solutions for substituting and muting of lost frames (GSM 06.21 [3]).