This TS contains an electronic copy of the ANSI-C code for the Floating-point Adaptive Multi-Rate Wideband codec. This floating-point codec specification is mainly targeted to be used in multimedia applications or in packet-based applications. The bit-exact fixed-point ANSI-C code in TS 26.173
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 artifacts.
The floating-point ANSI-C code in this TS is the only standard conforming non-bit-exact implementation of the Adaptive Multi-Rate Wideband speech transcoder (TS 26.190
), Voice Activity Detection (TS 26.194
), comfort noise generation (TS 26.192
), and source controlled rate operation (TS 26.193
). The floating-point code also contains example solutions for substituting and muting of lost frames (TS 26.191
The fixed-point specification in TS 26.173
shall remain the only allowed implementation for the 3G AMR-WB 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 fixed-point libraries are not used as such.