SPIRIT Adaptive Multi-Rate Wideband (AMR-WB) GSM speech transcoder is a
wideband codec with 6.6 - 23.85 kbps bit-rate range. Based on code excited
linear predictive (ACELP) model, the codec is fully compliant to the ITU-T
G.722.2 specification.
This speech coder is mainly used for toll quality speech compression in the
3rd generation mobile telephony applications.
Features
Nine input bit rates available (6.60, 8.85, 12.65, 14.25, 15.85, 18.25, 19.85, 23.05, 23.85 kbit/sec)
Encoder input in the form of 20 ms frames (320 samples per frame, sampled at 16 kHz)
Decoder output in the form of 20 ms frames (320 samples per frame)
Substitution and muting of lost frames
Discontinuous Transmission (DTX) support
Voice Activity Detection (VAD) support
Comfort Noise Generation (CNG) support
Code is reentrant, supports multithreading and dynamic memory allocation
Can be easily ported to any DSP or RISC platform.
Benefits
Highly optimized code ideal for resource constrained applications
