CVSD Military Speech Codec

Continuously Variable Slope Delta Modulation

CVSD is used in both commercial and military communications

MELPe Military Codec

Features List

  • Full Duplex codec
  • Functions are C-callable
  • Designed for Multi-channel operation

Also visit:

MELPe – Enhanced Mixed Excitation Linear Predictive (MELP) vocoder

A low bit-rate military codec known as standard MIL-STD-3005 and NATO STANAG 4591

CVSD Codec encodes voice signals at 1 bit per sample, so that audio sampled at 16kHz is encoded at 16 kbps.

Sampling Rate: 8 kHz  Coding Rate = 8000 bps
Sampling Rate: 12khz Coding Rate = 12000 bps
Sampling Rate: 16khz Coding Rate = 16000 bps

Availability

Platforms
Arm ® Devices – Armv7-A, Armv8-A, Armv9-A || Armv7-M / Armv8-M || Legacy Cortex-M3, ARM9e/ARM11
Texas Instruments – TI TMS320C7000 C7x, TMS320C6000 C64x/C64x+/C66, C674x, TMS320C5000 C55x
Win32 LIB / DLL
Linux i686

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

Specifications

NOTE: We specify MIPS (Millions of Instructions Per Second) as MCPS (Millions of Instruction Cycles Per Second). Unless otherwise specified, peak MIPS are indicated.

↓  Click on links below to view specification tables. 

ARM Cortex-A8 / A9 / A15

CPU UTILIZATION & MEMORY REQUIREMENTS
Cortex-A MIPS (Peak)
8000 hz/8000 bps12000 hz/12000 bps16000 hz/16000 bps
SoftwareEncodeDecodeEncodeDecodeEncodeDecode
CVSD1.61.62.42.43.23.28

All Memory usage is given in bytes.

Memory
FunctionProgram MemoryData Memory
Encoder | Decoder18721664

Cortex-M4

CPU UTILIZATION & MEMORY REQUIREMENTS
Cortex-M4 MIPS (Peak)
8000 hz/8000 bps12000 hz/12000 bps16000 hz/16000 bps
SoftwareEncodeDecodeEncodeDecodeEncodeDecode
CVSD1.61.62.42.43.23.28

All Memory usage is given in bytes.

Memory
FunctionProgram MemoryData Memory
Encoder | Decoder17921664

C64x / C64x+ / C66x / C67xx / C7x

CPU UTILIZATION & MEMORY REQUIREMENTS
C64x MIPS (Peak)
8000 hz/8000 bps12000 hz/12000 bps16000 hz/16000 bps
SoftwareEncodeDecodeEncodeDecodeEncodeDecode
CVSD0.20.20.30.30.40.41

All Memory usage is given in bytes.

Memory
FunctionProgram MemoryTablesData MemoryChannel
Encoder | Decoder5120014

CVSD C55x

CPU UTILIZATION
C64x MIPS (Peak)
8000 hz/8000 bps12000 hz/12000 bps16000 hz/16000 bps
SoftwareEncodeDecodeEncodeDecodeEncodeDecode
CVSD0.40.40.60.60.80.82

x86 32-Bit

MEMORY REQUIREMENTS
All Memory usage is given in bytes.
Memory
Channel InstanceProgram MemoryData Memory
4018721664

Win32 DLL & Static lib

MEMORY REQUIREMENTS
All Memory usage is given in bytes.
Memory
Channel InstanceProgram MemoryData Memory
407841400

Description

CVSD Codec (Continuously Variable Slope Delta Modulation) is used in both commercial and military communications where “toll-quality” is required, yet low computation complexity and low memory requirements are desirable.  As the name implies it is Delta modulation (DM*) with variable step size. A method by which a voice signal is digitized for transmission, and then changed back to an analogue voice signal during reception. The size of the steps of the approximated signal is progressively increased or decreased as required to make the approximated signal closely match the input analog wave. The CVSD Codec is a full duplex codec.

*Delta-modulation (DM) is a differential waveform quantization or coding technique. A DM encoder uses the error between the original signal to be coded and the coded signal itself to create a differentially quantized data stream. Codec

Function API's​

API function call summary

CVSD_ADT_reset (. . .)     Initializes the CVSD 
CVSD_ADT_encode (. . .)    Executes the CVSD encoder
CVSD_ADT_decode (. . .)    Executes the CVSD decoder

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