EVRC Speech Codec


EVRC ENHANCED VARIABLE RATE SPEECH CODEC C64x

DESCRIPTION

The Adaptive Digital Technologies Enhanced Variable Rate Codec (EVRC) is a real-time implementation of the 3GPP2 standardized vocoder. The vocoder, originally developed for cellular telephony, also has other applications in VoIP. The EVRC codec encodes 8 kHz sampled voice audio signals for transmission, and compresses the signals to 8550, 4000, and 800 bits per second.


Coding Rate: 8550, 4000, and 800 bits per second

Sampling Rate: 8 kHz

Delay: 20 milliseconds

 

EVRC 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 EVRC compliance data files.

  5. Includes Packet Loss Concealment Algorithm

  6. Includes Support for Discontinuous Transmission (DTX)

AVAILABILITY

ADT EVRC is available on the TMS320™ DSP Family


C64x™DSP Generations

SPECIFICATIONS

EVRC C64x

All memory requirements are in units of byte.

Software
Peak Loading(MIPS)
Program Memory
Data Memory
Scratch
Per-Channel Data Memory
Preliminary 25 175 KB 15 KB
5 KB
6 KB

FUNCTIONS


APPLICATIONS

Wireless/Mobile/Personal Communications (base-stations and handset)

Voice over Packet (Gateways)

Streaming Media Servers

 

 

 

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