SPIRIT GSM Enhanced Full Rate (GSM-EFR) has improved speech quality in
comparison with GSM Full Rate speech codec. Based on code excited linear
predictive (ACELP) model this codec operates at 12.2 bit rate. SPIRIT GSM
EFR is fully compliant to the ETSI GSM 06.90 specification.
Features
Input bitrate 12.2 kbit/sec
Encoder input in the form of 20 ms frames (160 samples per frame, sampled at 8 kHz)
Decoder output in the form of 20 ms frames (160 samples per frame)
Substitution and muting of lost frames
Discontinuous Transmission (DTX) support
Voice Activity Detection (VAD) support
Comfort Noise Generation (CNG) support
Simple application interface
Code is reentrant, supports multithreading and dynamic memory allocation
Benefits
Highly optimized code ideal for resource constrained applications
