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 
Delay: 20 milliseconds
Data sheet: .pdf ![]()
Functions are C-callable 
Multiple channel capable
Complies with ETSI test vectors. (bit-exact)
Can be integrated with echo cancellers, and tone detection/regeneration.
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)
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
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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:12/05/2008AMR_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
Wireless base stations and handset " Voice over Packet Gateways
Streaming Media Servers
SITE LINKS
HOMEVOCODERS
ADT 4800 ADT 9600 G.711 G.722 G.722.1 G.722.2 AMR-WB G.723.1 G.726 G.728 G.729, G.729 AB GSM AMR GSM FR LPC EVRC EVRC-B MELP MELPe SMV TDVC iLBCRELATED LINKS
PRODUCT INDEX G.168 NEC & LEC G.168 Lite G.168 EC CHIP 'C6424 G.168 EC CHIP 'C641x ACOUSTIC EC ACOUSTIC EC G2 LC IPP REFERENCE DESIGN DSP RESOURCE WIZARDAdaptive Digital is a member of:
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