Vocoders by Adaptive Digital

SMV - Selectable Mode Vocoder

SMV

ADT SMV C64x

AUDIO CODER

The Adaptive Digital Technologies Selectable Mode Vocoder (SMV) .pdf is a real-time implementation of the 3GPP2 standardized vocoder. The vocoder, originally developed for cellular telephony, also has other applications in VoIP. The SMV codec encodes 8 kHz sampled voice audio signals for transmission, and compresses the signals to rates of 8.55 4.0, or 2.0 kbps.

Coding Rate: 8.55 4.0, or 2.0 kbps

Sampling Rate: 8 kHz

Delay: 20 milliseconds

FEATURES

  1. Functions are C-callable.

  2. Multi–Channel Implementation.

  3. Completely re–entrant (Channel can interrupt any Channel, any time)

  4. The encoder and decoder meet all ITU SMV compliance data files.

  5. Includes Packet Loss Concealment Algorithm

  6. Includes Support for Discontinuous Transmission (DTX)

  7. Includes optional noise suppression

AVAILABILITY

ADT SMV is available on the TMS320™ DSP Family

C64x™ DSP Generation

 

SPECIFICATIONS

SMV C64x

All Memory usage is given in units of byte.

Function
MIPS
Program Memory
Data Memory
 Scratch Per Channel Data Mem
Preliminary 35 300 26 KB 15 KB 9.5 KB

Last update: 12/28/2005

 

FUNCTION

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

 

 

PRODUCTS