This TS contains an electronic copy of the ANSI-C code for a floating-point implementation of the Adaptive Multi-Rate codec. This floating-point codec specification is mainly targeted to be used in multimedia applications such as the 3G-324M terminal specified in TS 26.110
, or in packet-based (e.g., H.323) applications. The bit-exact fixed-point ANSI-C code in TS 26.073
remains the preferred implementation for all applications, but the floating-point codec may be used instead of the fixed-point codec when the implementation platform is better suited for a floating-point implementation. It has been verified that the fixed-point and floating-point codecs interoperate with each other without any artefacts.
The floating-point ANSI-C code in this TS is the only standard conforming non-bit-exact implementation of the Adaptive Multi Rate speech transcoder (TS 26.090
), Voice Activity Detection (TS 26.094
), comfort noise generation (TS 26.092
), and source controlled rate operation (TS 26.093
). The floating-point code also contains example solutions for substituting and muting of lost frames (TS 26.091
The fixed-point specification in TS 26.073
shall remain the only allowed implementation for the 3G mandatory speech service and the use of the floating-point codec is strictly limited to other services.
The floating-point encoder in this TS is a non-bit-exact implementation of the fixed-point encoder producing quality indistinguishable from that of the fixed-point encoder. The decoder in this TS is functionally a bit-exact implementation of the fixed-point decoder, but the code has been optimized for speed and the standard fixedpoint libraries are not used as such.