SMV

Selectable Mode Vocoder

SMV IS VARIABLE BITRATE SPEECH CODING STANDARD USED IN CDMA* NETWORKS

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Features List

  • Functions are C-callable
  • Designed for Multi-channel operation
  • Completely re–entrant (Channel can interrupt any Channel, any time)
  • Includes Packet Loss Concealment Algorithm
  • Includes Support for Discontinuous Transmission (DTX)
  • Includes optional noise suppression

Availability

Platforms
Texas Instruments – TI TMS320C6000 C64x / C64x+/ C66x / C674x

Coding Rate: 8.55 4.0, or 2.0 kbps

Sampling Rate: 8 kHz

Delay: 20 milliseconds

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

Specifications

SMV C6xx

CPU UTILIZATION & MEMORY REQUIREMENTS
All Memory usage is given in bytes.
SoftwareMIPSMemory
ModelPeakProgramData ScratchPer-Channel Data
SMV3530026 KB15 KB9.5 KB

 

Description

The Adaptive Digital Technologies Selectable Mode Vocoder (SMV)is a real-time implementation of the 3GPP2 standardized speech codec. The vocoder, originally developed for cellular telephony, also has other applications in VoIP.

SMV provides a number of operating points, or average bit rate set points, allowing operators to make their own voice quality/system capacity trade-offs. These trade-offs can be made on a static basis, such as call set-up, or on a dynamic basis, allowing for a reduction in voice quality to manage localized capacity problems.

SMV is required to operate at a number of average bit rate setpoints, allowing for each service provider to perform their own voice quality/system capacity trade off. As a result, the SMV design includes multiple modes; each associated with an average bit rate limitation.

*Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies.

Function API's​

API function call summary

SMVENC_ADT_init Initializes an Encode Channel
SMVDEC_ADT_init Initializes an Decode Channel 
SMVENC_ADT_encode Encodes a frame of data 

SMVDEC_ADT_decode Decodes a frame of data
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