MELP - Mixed Excitation Linear Predictive

Department of Defense (DoD) Speech Coding Standard

Suitable for band limited or efficiency limited communication systems such as satellite links and military applications.

Nato communications
Airline Technology

Features List

  • Functions are C-callable

  • Multiple channel capable

  • NATO standard codec

  • Efficient in computational requirements

MELP DoD standard specifies a 2400 bps mode of operation.
MELPe is a triple-rate low codec that supports rates of 600 bps, 1200 bps, and 2400 bps. 

Coding Rate: 2.4 kbps
Sampling Rate: 8 kHz


Arm ® Devices Armv7-A || Armv7-M / Armv8-M || Legacy Cortex-M3, ARM9E
Texas Instruments – TI TMS320C6000 C64x/C64x+/C66x, C674x, C62/C67 | TMS320C5000 C55x

ADT MELP is available on the above Platforms: Other configurations are available upon request.



MELP Speech Coder was developed by the US military based upon the LPC-based CELP standard vocoder for low-bitrate communications. It is very efficient in its computational requirements. This translates into relatively low power consumption, an important consideration for portable systems. 

MELP codec is robust in difficult background noise environments such as found in military communications. 

MELP is used mainly in military applications and satellite communications, secure voice, and secure radio devices.

Function API's

API function call summary

InitializeMelpEncoderChannel (. . .) Initializes the MELP encoder
InitializeMelpDecoderChannel (. . .) Initializes the MELP decoder
EncodeMelp (. . .) Executes the MELP encoder
DecodeMelp (. . .) Executes the MELP decoder

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