ESPICO

Specialists in Speech and Audio Software Development

Material Copyright © 2023 ESPICO Ltd

ETSI NB-AMR

The ETSI standard AMR (Adaptive Multi-Rate) narrow band speech codec belongs to the ACELP family of speech coders. Narrow band AMR operates at eight different bit rates from 4.75kbps to 12.2kbps and incorporates the second-generation vocoder standards EFR-GSM (12.2kbps mode) and IS-641-A (7.4kbps mode). Discontinuous transmission (DTX) functionality is also part of the standard with a choice of two different Voice Activity Detection (VAD) algorithms, VAD1 and VAD2. The ESPICO software includes both algorithms. The codec operates on speech frames of 20ms (160 samples) with a 5ms look-ahead.


The ESPICO implementations are highly optimised, realising low memory and MHz requirements. Contact ESPICO for specific resource requirements.

Features


Availability


ESPICO’s optimised solution can be ported to any platform. Available solutions include:


Applications