GSM AMR codec by CONSILIENT TECHNOLOGIES PVT LTD

Audio and Voice Solutions

Product Description

GSM-AMR is an Adaptive Multi Rate (AMR) speech coder standard introduced by the 3rd Generation Partnership Project (3GPP), which is a partnership project of various standards organizations, for compressing the toll quality speech (8000 samples/second).  This speech coder is mainly used for speech compression in the 3rd generation mobile telephony.

 

This codec has eight basic bit rates, 12.2, 10.2, 7.95, 7.40, 6.70, 5.90, 5.15 and 4.75 Kbit/s.  This codec works on the principle of Algebraic Code Excited Linear Prediction (ACELP) for all bit rates.  To reduce average bit rate, this codec supports the discontinuous transmission (DTX), using Voice Activity Detection (VAD) and Comfort Noise Generation (CNG) algorithms.  There are two types of VAD algorithms.

The codec library is well optimised for both ARM9E and NEON platforms.

• It operates at 8kHz sampling rate and sends out encoded data bits every 20ms.
• Fully compatible with the following 3GPP GSM-AMR standards

     3GPP TS 26.090 V4.0.0                      AMR Speech Codec; Transcoding functions

      3GPP TS 26.071 V4.0.0                      AMR Speech Codec; General Description

     3GPP TS 26.091 V4.0.0                      AMR Speech Codec; Error concealment of lost frames

     3GPP TS 26.092 V4.0.0                      AMR Speech Codec; Comfort noise aspects

      3GPP TS 26.093 V4.0.0                      AMR Speech Codec; Source controlled rate operation

      3GPP TS 26.094 V4.0.0                      AMR Speech Codec; Voice activity detector

• Fully bit exact with the following 3GPP GSM-AMR standard reference code

                 3GPP TS 26.071 V4.0.0                      ANSI-C code for AMR speech codec

                    (Code Version 7.6.0)

 

 

GSM AMR codec

Market Segment(s)

• Embedded
• Mobile

Target Platform(s)

• Android
• Linux
• Other OS

ARM Processor(s)

• ARM926EJ-S
• Cortex-A9
• ARMv5
• ARMv6

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