GSM/AMR Adaptive Multi-Rate speech coder

Vocoders by Adaptive Digital

ADT GSM AMR SPEECH CODER  C54x , C55x , C64x

DESCRIPTION

GSM-AMR is an adaptive multi-rate speech coder that has been standardized for use in Third Generation (3G) mobile telephony. The coder supports eight bit rates: 12.2, 10.2, 7.95, 7.40, 6.7, 5.9, 5.15, and 4.75 kbps. The coder uses algebraic code excited linear prediction (ACELP) as the compression method. AMR also includes Voice Activity Detection (VAD) and Discontinuous Transmission (DTX) as an added way to save bandwidth by sending fewer bits per second when the user is not speaking. GSM-AMR was developed to maintain high speech quality under a wide range of transmission conditions.

Coding Rate: 12.2, 10.2, 7.95, 7.40, 6.7, 5.9, 5.15, and 4.75 kbps

Sampling Rate: 8 kHz gsm/amr

Delay: 20 milliseconds

Data sheet: .pdf

FEATURES

  1. Functions are C-callable

  2. Multiple channel capable

  3. Complies with ETSI test vectors. (bit-exact)

  4. Can be integrated with echo cancellers, and tone detection/regeneration.

AVAILABILITY

ADT GSM AMR is available on the TMS320™ DSP Family

C54x™DSP, C55x™DSP, C64x™DSP & C64x+™DSP Generations

Related links: GSM FR (Full Rate)

SPECIFICATIONS

Note: All CPU usage given in MIPS (also known as MCPS or MHz)

GSM AMR C54x

All Memory usage is given in units of 16-bit word.

Software MIPS Program Memory Data Memory Per-Channel Data Memory Scratch Memory
Encode VAD2 18.8 19591 16725 1022 5065
Decode 2.3 8164 13604 >608 868
Encode VAD2 / Decode 21.1 25949 16191 1624 5415

Current - last update: 07/17/2008

GSM AMR C55x

All Memory usage is given in units of byte.

Function MIPS Program Mem Data Mem Per-channel Data Mem Scratch Mem
Encode 17.1 37782 28364 1996 6424
Decode 2.6 19840 28952 1316 1200

Current - last update: 07/03/2008

GSM AMR C64x

All Memory usage is given in units of byte.

Function MIPS Program Mem Data Mem Per-channel Data Mem Scratch Mem
Encoder (Vad1) 13.1 107668 31158 1992 9360
Encoder (Vad2) 13.1 108148 31880 2064 9360
Decoder 3.0 53308 31988 1232 1392
Encoder (Vad1)/Decode 16.0 150556 32172 3224 10752
Encoder (Vad2)/Decode 16.0 151036 32892 3296 10752

GSM AMR C64x +

All Memory usage is given in units of byte.

Function MIPS Program Mem Data Mem Per-channel Data Mem Scratch Mem
Encoder (Vad1) 13.1 78772 31158 1992 9360
Encoder (Vad2) 13.1 79700 31880 2064 9360
Decoder 2.8 38332 31988 1232 1392
Encoder (Vad1)/Decode 15.7 109724 32172 3224 10752
Encoder (Vad2)/Decode 15.7 110652 32892 3296 10752

* Peak Mips figures vary depending on the data rate and whether DTX is enabled. The values listed in the above tables were recorded with DTX disabled, and represent the worst-case across all data rates. The Vad1 option increases MIPS by an extra 0.9 MIPS, and Vad2 increases MIPS by an extra 2.8 MIPS.

Last update:12/05/2008

FUNCTION

AMR_ADT_encInit(. . .) Initializes the AMR encoder

AMR_ADT_decInit(. . .) Initializes the AMR decoder

AMR_ADT_encode(. . .) Executes the AMR encoder

AMR_ADT_decode(. . .) Executes the AMR decoder

 

APPLICATIONS

Wireless base stations and handset " Voice over Packet Gateways

Streaming Media Servers

 

 

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